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mbedtls/library/psa_crypto.c
Gilles Peskine 2d0b7231f7
Merge pull request #3712 from jdurkop/psa-crypto-config-ecdsa-3670 
Introduce MBEDTLS_PSA_CRYPTO_CONFIG and use it for ECDSA
2020-10-27 17:40:04 +01:00

6336 lines
219 KiB
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/*
* PSA crypto layer on top of Mbed TLS crypto
*/
/*
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "common.h"
#if defined(MBEDTLS_PSA_CRYPTO_C)
#include "psa_crypto_service_integration.h"
#include "psa/crypto.h"
#include "psa_crypto_core.h"
#include "psa_crypto_invasive.h"
#include "psa_crypto_driver_wrappers.h"
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
#include "psa_crypto_se.h"
#endif
#include "psa_crypto_slot_management.h"
/* Include internal declarations that are useful for implementing persistently
* stored keys. */
#include "psa_crypto_storage.h"
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include "mbedtls/platform.h"
#if !defined(MBEDTLS_PLATFORM_C)
#define mbedtls_calloc calloc
#define mbedtls_free free
#endif
#include "mbedtls/arc4.h"
#include "mbedtls/asn1.h"
#include "mbedtls/asn1write.h"
#include "mbedtls/bignum.h"
#include "mbedtls/blowfish.h"
#include "mbedtls/camellia.h"
#include "mbedtls/chacha20.h"
#include "mbedtls/chachapoly.h"
#include "mbedtls/cipher.h"
#include "mbedtls/ccm.h"
#include "mbedtls/cmac.h"
#include "mbedtls/ctr_drbg.h"
#include "mbedtls/des.h"
#include "mbedtls/ecdh.h"
#include "mbedtls/ecp.h"
#include "mbedtls/entropy.h"
#include "mbedtls/error.h"
#include "mbedtls/gcm.h"
#include "mbedtls/md2.h"
#include "mbedtls/md4.h"
#include "mbedtls/md5.h"
#include "mbedtls/md.h"
#include "mbedtls/md_internal.h"
#include "mbedtls/pk.h"
#include "mbedtls/pk_internal.h"
#include "mbedtls/platform_util.h"
#include "mbedtls/error.h"
#include "mbedtls/ripemd160.h"
#include "mbedtls/rsa.h"
#include "mbedtls/sha1.h"
#include "mbedtls/sha256.h"
#include "mbedtls/sha512.h"
#include "mbedtls/xtea.h"
#define ARRAY_LENGTH( array ) ( sizeof( array ) / sizeof( *( array ) ) )
/* constant-time buffer comparison */
static inline int safer_memcmp( const uint8_t *a, const uint8_t *b, size_t n )
{
size_t i;
unsigned char diff = 0;
for( i = 0; i < n; i++ )
diff |= a[i] ^ b[i];
return( diff );
}
/****************************************************************/
/* Global data, support functions and library management */
/****************************************************************/
static int key_type_is_raw_bytes( psa_key_type_t type )
{
return( PSA_KEY_TYPE_IS_UNSTRUCTURED( type ) );
}
/* Values for psa_global_data_t::rng_state */
#define RNG_NOT_INITIALIZED 0
#define RNG_INITIALIZED 1
#define RNG_SEEDED 2
typedef struct
{
void (* entropy_init )( mbedtls_entropy_context *ctx );
void (* entropy_free )( mbedtls_entropy_context *ctx );
mbedtls_entropy_context entropy;
mbedtls_ctr_drbg_context ctr_drbg;
unsigned initialized : 1;
unsigned rng_state : 2;
} psa_global_data_t;
static psa_global_data_t global_data;
#define GUARD_MODULE_INITIALIZED \
if( global_data.initialized == 0 ) \
return( PSA_ERROR_BAD_STATE );
psa_status_t mbedtls_to_psa_error( int ret )
{
/* If there's both a high-level code and low-level code, dispatch on
* the high-level code. */
switch( ret < -0x7f ? - ( -ret & 0x7f80 ) : ret )
{
case 0:
return( PSA_SUCCESS );
case MBEDTLS_ERR_AES_INVALID_KEY_LENGTH:
case MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH:
case MBEDTLS_ERR_AES_FEATURE_UNAVAILABLE:
return( PSA_ERROR_NOT_SUPPORTED );
case MBEDTLS_ERR_AES_HW_ACCEL_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
case MBEDTLS_ERR_ARC4_HW_ACCEL_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
case MBEDTLS_ERR_ASN1_OUT_OF_DATA:
case MBEDTLS_ERR_ASN1_UNEXPECTED_TAG:
case MBEDTLS_ERR_ASN1_INVALID_LENGTH:
case MBEDTLS_ERR_ASN1_LENGTH_MISMATCH:
case MBEDTLS_ERR_ASN1_INVALID_DATA:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_ASN1_ALLOC_FAILED:
return( PSA_ERROR_INSUFFICIENT_MEMORY );
case MBEDTLS_ERR_ASN1_BUF_TOO_SMALL:
return( PSA_ERROR_BUFFER_TOO_SMALL );
#if defined(MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA)
case MBEDTLS_ERR_BLOWFISH_BAD_INPUT_DATA:
#elif defined(MBEDTLS_ERR_BLOWFISH_INVALID_KEY_LENGTH)
case MBEDTLS_ERR_BLOWFISH_INVALID_KEY_LENGTH:
#endif
case MBEDTLS_ERR_BLOWFISH_INVALID_INPUT_LENGTH:
return( PSA_ERROR_NOT_SUPPORTED );
case MBEDTLS_ERR_BLOWFISH_HW_ACCEL_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
#if defined(MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA)
case MBEDTLS_ERR_CAMELLIA_BAD_INPUT_DATA:
#elif defined(MBEDTLS_ERR_CAMELLIA_INVALID_KEY_LENGTH)
case MBEDTLS_ERR_CAMELLIA_INVALID_KEY_LENGTH:
#endif
case MBEDTLS_ERR_CAMELLIA_INVALID_INPUT_LENGTH:
return( PSA_ERROR_NOT_SUPPORTED );
case MBEDTLS_ERR_CAMELLIA_HW_ACCEL_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
case MBEDTLS_ERR_CCM_BAD_INPUT:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_CCM_AUTH_FAILED:
return( PSA_ERROR_INVALID_SIGNATURE );
case MBEDTLS_ERR_CCM_HW_ACCEL_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
case MBEDTLS_ERR_CHACHA20_BAD_INPUT_DATA:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_CHACHAPOLY_BAD_STATE:
return( PSA_ERROR_BAD_STATE );
case MBEDTLS_ERR_CHACHAPOLY_AUTH_FAILED:
return( PSA_ERROR_INVALID_SIGNATURE );
case MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE:
return( PSA_ERROR_NOT_SUPPORTED );
case MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_CIPHER_ALLOC_FAILED:
return( PSA_ERROR_INSUFFICIENT_MEMORY );
case MBEDTLS_ERR_CIPHER_INVALID_PADDING:
return( PSA_ERROR_INVALID_PADDING );
case MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_CIPHER_AUTH_FAILED:
return( PSA_ERROR_INVALID_SIGNATURE );
case MBEDTLS_ERR_CIPHER_INVALID_CONTEXT:
return( PSA_ERROR_CORRUPTION_DETECTED );
case MBEDTLS_ERR_CIPHER_HW_ACCEL_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
case MBEDTLS_ERR_CMAC_HW_ACCEL_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
case MBEDTLS_ERR_CTR_DRBG_ENTROPY_SOURCE_FAILED:
return( PSA_ERROR_INSUFFICIENT_ENTROPY );
case MBEDTLS_ERR_CTR_DRBG_REQUEST_TOO_BIG:
case MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG:
return( PSA_ERROR_NOT_SUPPORTED );
case MBEDTLS_ERR_CTR_DRBG_FILE_IO_ERROR:
return( PSA_ERROR_INSUFFICIENT_ENTROPY );
case MBEDTLS_ERR_DES_INVALID_INPUT_LENGTH:
return( PSA_ERROR_NOT_SUPPORTED );
case MBEDTLS_ERR_DES_HW_ACCEL_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
case MBEDTLS_ERR_ENTROPY_NO_SOURCES_DEFINED:
case MBEDTLS_ERR_ENTROPY_NO_STRONG_SOURCE:
case MBEDTLS_ERR_ENTROPY_SOURCE_FAILED:
return( PSA_ERROR_INSUFFICIENT_ENTROPY );
case MBEDTLS_ERR_GCM_AUTH_FAILED:
return( PSA_ERROR_INVALID_SIGNATURE );
case MBEDTLS_ERR_GCM_BAD_INPUT:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_GCM_HW_ACCEL_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
case MBEDTLS_ERR_MD2_HW_ACCEL_FAILED:
case MBEDTLS_ERR_MD4_HW_ACCEL_FAILED:
case MBEDTLS_ERR_MD5_HW_ACCEL_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
case MBEDTLS_ERR_MD_FEATURE_UNAVAILABLE:
return( PSA_ERROR_NOT_SUPPORTED );
case MBEDTLS_ERR_MD_BAD_INPUT_DATA:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_MD_ALLOC_FAILED:
return( PSA_ERROR_INSUFFICIENT_MEMORY );
case MBEDTLS_ERR_MD_FILE_IO_ERROR:
return( PSA_ERROR_STORAGE_FAILURE );
case MBEDTLS_ERR_MD_HW_ACCEL_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
case MBEDTLS_ERR_MPI_FILE_IO_ERROR:
return( PSA_ERROR_STORAGE_FAILURE );
case MBEDTLS_ERR_MPI_BAD_INPUT_DATA:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_MPI_INVALID_CHARACTER:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_MPI_BUFFER_TOO_SMALL:
return( PSA_ERROR_BUFFER_TOO_SMALL );
case MBEDTLS_ERR_MPI_NEGATIVE_VALUE:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_MPI_DIVISION_BY_ZERO:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_MPI_NOT_ACCEPTABLE:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_MPI_ALLOC_FAILED:
return( PSA_ERROR_INSUFFICIENT_MEMORY );
case MBEDTLS_ERR_PK_ALLOC_FAILED:
return( PSA_ERROR_INSUFFICIENT_MEMORY );
case MBEDTLS_ERR_PK_TYPE_MISMATCH:
case MBEDTLS_ERR_PK_BAD_INPUT_DATA:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_PK_FILE_IO_ERROR:
return( PSA_ERROR_STORAGE_FAILURE );
case MBEDTLS_ERR_PK_KEY_INVALID_VERSION:
case MBEDTLS_ERR_PK_KEY_INVALID_FORMAT:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_PK_UNKNOWN_PK_ALG:
return( PSA_ERROR_NOT_SUPPORTED );
case MBEDTLS_ERR_PK_PASSWORD_REQUIRED:
case MBEDTLS_ERR_PK_PASSWORD_MISMATCH:
return( PSA_ERROR_NOT_PERMITTED );
case MBEDTLS_ERR_PK_INVALID_PUBKEY:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_PK_INVALID_ALG:
case MBEDTLS_ERR_PK_UNKNOWN_NAMED_CURVE:
case MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE:
return( PSA_ERROR_NOT_SUPPORTED );
case MBEDTLS_ERR_PK_SIG_LEN_MISMATCH:
return( PSA_ERROR_INVALID_SIGNATURE );
case MBEDTLS_ERR_PK_HW_ACCEL_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
case MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
case MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED:
return( PSA_ERROR_NOT_SUPPORTED );
case MBEDTLS_ERR_RIPEMD160_HW_ACCEL_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
case MBEDTLS_ERR_RSA_BAD_INPUT_DATA:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_RSA_INVALID_PADDING:
return( PSA_ERROR_INVALID_PADDING );
case MBEDTLS_ERR_RSA_KEY_GEN_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
case MBEDTLS_ERR_RSA_KEY_CHECK_FAILED:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_RSA_PUBLIC_FAILED:
case MBEDTLS_ERR_RSA_PRIVATE_FAILED:
return( PSA_ERROR_CORRUPTION_DETECTED );
case MBEDTLS_ERR_RSA_VERIFY_FAILED:
return( PSA_ERROR_INVALID_SIGNATURE );
case MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE:
return( PSA_ERROR_BUFFER_TOO_SMALL );
case MBEDTLS_ERR_RSA_RNG_FAILED:
return( PSA_ERROR_INSUFFICIENT_MEMORY );
case MBEDTLS_ERR_RSA_UNSUPPORTED_OPERATION:
return( PSA_ERROR_NOT_SUPPORTED );
case MBEDTLS_ERR_RSA_HW_ACCEL_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
case MBEDTLS_ERR_SHA1_HW_ACCEL_FAILED:
case MBEDTLS_ERR_SHA256_HW_ACCEL_FAILED:
case MBEDTLS_ERR_SHA512_HW_ACCEL_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
case MBEDTLS_ERR_XTEA_INVALID_INPUT_LENGTH:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_XTEA_HW_ACCEL_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
case MBEDTLS_ERR_ECP_BAD_INPUT_DATA:
case MBEDTLS_ERR_ECP_INVALID_KEY:
return( PSA_ERROR_INVALID_ARGUMENT );
case MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL:
return( PSA_ERROR_BUFFER_TOO_SMALL );
case MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE:
return( PSA_ERROR_NOT_SUPPORTED );
case MBEDTLS_ERR_ECP_SIG_LEN_MISMATCH:
case MBEDTLS_ERR_ECP_VERIFY_FAILED:
return( PSA_ERROR_INVALID_SIGNATURE );
case MBEDTLS_ERR_ECP_ALLOC_FAILED:
return( PSA_ERROR_INSUFFICIENT_MEMORY );
case MBEDTLS_ERR_ECP_HW_ACCEL_FAILED:
return( PSA_ERROR_HARDWARE_FAILURE );
case MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED:
return( PSA_ERROR_CORRUPTION_DETECTED );
default:
return( PSA_ERROR_GENERIC_ERROR );
}
}
/****************************************************************/
/* Key management */
/****************************************************************/
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
static inline int psa_key_slot_is_external( const psa_key_slot_t *slot )
{
return( psa_key_lifetime_is_external( slot->attr.lifetime ) );
}
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
#if defined(MBEDTLS_ECP_C)
mbedtls_ecp_group_id mbedtls_ecc_group_of_psa( psa_ecc_family_t curve,
size_t byte_length )
{
switch( curve )
{
case PSA_ECC_FAMILY_SECP_R1:
switch( byte_length )
{
case PSA_BITS_TO_BYTES( 192 ):
return( MBEDTLS_ECP_DP_SECP192R1 );
case PSA_BITS_TO_BYTES( 224 ):
return( MBEDTLS_ECP_DP_SECP224R1 );
case PSA_BITS_TO_BYTES( 256 ):
return( MBEDTLS_ECP_DP_SECP256R1 );
case PSA_BITS_TO_BYTES( 384 ):
return( MBEDTLS_ECP_DP_SECP384R1 );
case PSA_BITS_TO_BYTES( 521 ):
return( MBEDTLS_ECP_DP_SECP521R1 );
default:
return( MBEDTLS_ECP_DP_NONE );
}
break;
case PSA_ECC_FAMILY_BRAINPOOL_P_R1:
switch( byte_length )
{
case PSA_BITS_TO_BYTES( 256 ):
return( MBEDTLS_ECP_DP_BP256R1 );
case PSA_BITS_TO_BYTES( 384 ):
return( MBEDTLS_ECP_DP_BP384R1 );
case PSA_BITS_TO_BYTES( 512 ):
return( MBEDTLS_ECP_DP_BP512R1 );
default:
return( MBEDTLS_ECP_DP_NONE );
}
break;
case PSA_ECC_FAMILY_MONTGOMERY:
switch( byte_length )
{
case PSA_BITS_TO_BYTES( 255 ):
return( MBEDTLS_ECP_DP_CURVE25519 );
case PSA_BITS_TO_BYTES( 448 ):
return( MBEDTLS_ECP_DP_CURVE448 );
default:
return( MBEDTLS_ECP_DP_NONE );
}
break;
case PSA_ECC_FAMILY_SECP_K1:
switch( byte_length )
{
case PSA_BITS_TO_BYTES( 192 ):
return( MBEDTLS_ECP_DP_SECP192K1 );
case PSA_BITS_TO_BYTES( 224 ):
return( MBEDTLS_ECP_DP_SECP224K1 );
case PSA_BITS_TO_BYTES( 256 ):
return( MBEDTLS_ECP_DP_SECP256K1 );
default:
return( MBEDTLS_ECP_DP_NONE );
}
break;
default:
return( MBEDTLS_ECP_DP_NONE );
}
}
#endif /* defined(MBEDTLS_ECP_C) */
static psa_status_t validate_unstructured_key_bit_size( psa_key_type_t type,
size_t bits )
{
/* Check that the bit size is acceptable for the key type */
switch( type )
{
case PSA_KEY_TYPE_RAW_DATA:
#if defined(MBEDTLS_MD_C)
case PSA_KEY_TYPE_HMAC:
#endif
case PSA_KEY_TYPE_DERIVE:
break;
#if defined(MBEDTLS_AES_C)
case PSA_KEY_TYPE_AES:
if( bits != 128 && bits != 192 && bits != 256 )
return( PSA_ERROR_INVALID_ARGUMENT );
break;
#endif
#if defined(MBEDTLS_CAMELLIA_C)
case PSA_KEY_TYPE_CAMELLIA:
if( bits != 128 && bits != 192 && bits != 256 )
return( PSA_ERROR_INVALID_ARGUMENT );
break;
#endif
#if defined(MBEDTLS_DES_C)
case PSA_KEY_TYPE_DES:
if( bits != 64 && bits != 128 && bits != 192 )
return( PSA_ERROR_INVALID_ARGUMENT );
break;
#endif
#if defined(MBEDTLS_ARC4_C)
case PSA_KEY_TYPE_ARC4:
if( bits < 8 || bits > 2048 )
return( PSA_ERROR_INVALID_ARGUMENT );
break;
#endif
#if defined(MBEDTLS_CHACHA20_C)
case PSA_KEY_TYPE_CHACHA20:
if( bits != 256 )
return( PSA_ERROR_INVALID_ARGUMENT );
break;
#endif
default:
return( PSA_ERROR_NOT_SUPPORTED );
}
if( bits % 8 != 0 )
return( PSA_ERROR_INVALID_ARGUMENT );
return( PSA_SUCCESS );
}
#if defined(MBEDTLS_RSA_C)
#if defined(MBEDTLS_PK_PARSE_C)
/* Mbed TLS doesn't support non-byte-aligned key sizes (i.e. key sizes
* that are not a multiple of 8) well. For example, there is only
* mbedtls_rsa_get_len(), which returns a number of bytes, and no
* way to return the exact bit size of a key.
* To keep things simple, reject non-byte-aligned key sizes. */
static psa_status_t psa_check_rsa_key_byte_aligned(
const mbedtls_rsa_context *rsa )
{
mbedtls_mpi n;
psa_status_t status;
mbedtls_mpi_init( &n );
status = mbedtls_to_psa_error(
mbedtls_rsa_export( rsa, &n, NULL, NULL, NULL, NULL ) );
if( status == PSA_SUCCESS )
{
if( mbedtls_mpi_bitlen( &n ) % 8 != 0 )
status = PSA_ERROR_NOT_SUPPORTED;
}
mbedtls_mpi_free( &n );
return( status );
}
#endif /* MBEDTLS_PK_PARSE_C */
/** Load the contents of a key buffer into an internal RSA representation
*
* \param[in] type The type of key contained in \p data.
* \param[in] data The buffer from which to load the representation.
* \param[in] data_length The size in bytes of \p data.
* \param[out] p_rsa Returns a pointer to an RSA context on success.
* The caller is responsible for freeing both the
* contents of the context and the context itself
* when done.
*/
static psa_status_t psa_load_rsa_representation( psa_key_type_t type,
const uint8_t *data,
size_t data_length,
mbedtls_rsa_context **p_rsa )
{
#if defined(MBEDTLS_PK_PARSE_C)
psa_status_t status;
mbedtls_pk_context ctx;
size_t bits;
mbedtls_pk_init( &ctx );
/* Parse the data. */
if( PSA_KEY_TYPE_IS_KEY_PAIR( type ) )
status = mbedtls_to_psa_error(
mbedtls_pk_parse_key( &ctx, data, data_length, NULL, 0 ) );
else
status = mbedtls_to_psa_error(
mbedtls_pk_parse_public_key( &ctx, data, data_length ) );
if( status != PSA_SUCCESS )
goto exit;
/* We have something that the pkparse module recognizes. If it is a
* valid RSA key, store it. */
if( mbedtls_pk_get_type( &ctx ) != MBEDTLS_PK_RSA )
{
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
/* The size of an RSA key doesn't have to be a multiple of 8. Mbed TLS
* supports non-byte-aligned key sizes, but not well. For example,
* mbedtls_rsa_get_len() returns the key size in bytes, not in bits. */
bits = PSA_BYTES_TO_BITS( mbedtls_rsa_get_len( mbedtls_pk_rsa( ctx ) ) );
if( bits > PSA_VENDOR_RSA_MAX_KEY_BITS )
{
status = PSA_ERROR_NOT_SUPPORTED;
goto exit;
}
status = psa_check_rsa_key_byte_aligned( mbedtls_pk_rsa( ctx ) );
if( status != PSA_SUCCESS )
goto exit;
/* Copy out the pointer to the RSA context, and reset the PK context
* such that pk_free doesn't free the RSA context we just grabbed. */
*p_rsa = mbedtls_pk_rsa( ctx );
ctx.pk_info = NULL;
exit:
mbedtls_pk_free( &ctx );
return( status );
#else
(void) data;
(void) data_length;
(void) type;
(void) rsa;
return( PSA_ERROR_NOT_SUPPORTED );
#endif /* MBEDTLS_PK_PARSE_C */
}
/** Export an RSA key to export representation
*
* \param[in] type The type of key (public/private) to export
* \param[in] rsa The internal RSA representation from which to export
* \param[out] data The buffer to export to
* \param[in] data_size The length of the buffer to export to
* \param[out] data_length The amount of bytes written to \p data
*/
static psa_status_t psa_export_rsa_key( psa_key_type_t type,
mbedtls_rsa_context *rsa,
uint8_t *data,
size_t data_size,
size_t *data_length )
{
#if defined(MBEDTLS_PK_WRITE_C)
int ret;
mbedtls_pk_context pk;
uint8_t *pos = data + data_size;
mbedtls_pk_init( &pk );
pk.pk_info = &mbedtls_rsa_info;
pk.pk_ctx = rsa;
/* PSA Crypto API defines the format of an RSA key as a DER-encoded
* representation of the non-encrypted PKCS#1 RSAPrivateKey for a
* private key and of the RFC3279 RSAPublicKey for a public key. */
if( PSA_KEY_TYPE_IS_KEY_PAIR( type ) )
ret = mbedtls_pk_write_key_der( &pk, data, data_size );
else
ret = mbedtls_pk_write_pubkey( &pos, data, &pk );
if( ret < 0 )
{
/* Clean up in case pk_write failed halfway through. */
memset( data, 0, data_size );
return( mbedtls_to_psa_error( ret ) );
}
/* The mbedtls_pk_xxx functions write to the end of the buffer.
* Move the data to the beginning and erase remaining data
* at the original location. */
if( 2 * (size_t) ret <= data_size )
{
memcpy( data, data + data_size - ret, ret );
memset( data + data_size - ret, 0, ret );
}
else if( (size_t) ret < data_size )
{
memmove( data, data + data_size - ret, ret );
memset( data + ret, 0, data_size - ret );
}
*data_length = ret;
return( PSA_SUCCESS );
#else
(void) type;
(void) rsa;
(void) data;
(void) data_size;
(void) data_length;
return( PSA_ERROR_NOT_SUPPORTED );
#endif /* MBEDTLS_PK_WRITE_C */
}
/** Import an RSA key from import representation to a slot
*
* \param[in,out] slot The slot where to store the export representation to
* \param[in] data The buffer containing the import representation
* \param[in] data_length The amount of bytes in \p data
*/
static psa_status_t psa_import_rsa_key( psa_key_slot_t *slot,
const uint8_t *data,
size_t data_length )
{
psa_status_t status;
uint8_t* output = NULL;
mbedtls_rsa_context *rsa = NULL;
/* Parse input */
status = psa_load_rsa_representation( slot->attr.type,
data,
data_length,
&rsa );
if( status != PSA_SUCCESS )
goto exit;
slot->attr.bits = (psa_key_bits_t) PSA_BYTES_TO_BITS(
mbedtls_rsa_get_len( rsa ) );
/* Re-export the data to PSA export format, such that we can store export
* representation in the key slot. Export representation in case of RSA is
* the smallest representation that's allowed as input, so a straight-up
* allocation of the same size as the input buffer will be large enough. */
output = mbedtls_calloc( 1, data_length );
if( output == NULL )
{
status = PSA_ERROR_INSUFFICIENT_MEMORY;
goto exit;
}
status = psa_export_rsa_key( slot->attr.type,
rsa,
output,
data_length,
&data_length);
exit:
/* Always free the RSA object */
mbedtls_rsa_free( rsa );
mbedtls_free( rsa );
/* Free the allocated buffer only on error. */
if( status != PSA_SUCCESS )
{
mbedtls_free( output );
return( status );
}
/* On success, store the allocated export-formatted key. */
slot->data.key.data = output;
slot->data.key.bytes = data_length;
return( PSA_SUCCESS );
}
#endif /* defined(MBEDTLS_RSA_C) */
#if defined(MBEDTLS_ECP_C)
/** Load the contents of a key buffer into an internal ECP representation
*
* \param[in] type The type of key contained in \p data.
* \param[in] data The buffer from which to load the representation.
* \param[in] data_length The size in bytes of \p data.
* \param[out] p_ecp Returns a pointer to an ECP context on success.
* The caller is responsible for freeing both the
* contents of the context and the context itself
* when done.
*/
static psa_status_t psa_load_ecp_representation( psa_key_type_t type,
const uint8_t *data,
size_t data_length,
mbedtls_ecp_keypair **p_ecp )
{
mbedtls_ecp_group_id grp_id = MBEDTLS_ECP_DP_NONE;
psa_status_t status;
mbedtls_ecp_keypair *ecp = NULL;
size_t curve_size = data_length;
if( PSA_KEY_TYPE_IS_PUBLIC_KEY( type ) &&
PSA_KEY_TYPE_ECC_GET_FAMILY( type ) != PSA_ECC_FAMILY_MONTGOMERY )
{
/* A Weierstrass public key is represented as:
* - The byte 0x04;
* - `x_P` as a `ceiling(m/8)`-byte string, big-endian;
* - `y_P` as a `ceiling(m/8)`-byte string, big-endian.
* So its data length is 2m+1 where n is the key size in bits.
*/
if( ( data_length & 1 ) == 0 )
return( PSA_ERROR_INVALID_ARGUMENT );
curve_size = data_length / 2;
/* Montgomery public keys are represented in compressed format, meaning
* their curve_size is equal to the amount of input. */
/* Private keys are represented in uncompressed private random integer
* format, meaning their curve_size is equal to the amount of input. */
}
/* Allocate and initialize a key representation. */
ecp = mbedtls_calloc( 1, sizeof( mbedtls_ecp_keypair ) );
if( ecp == NULL )
return( PSA_ERROR_INSUFFICIENT_MEMORY );
mbedtls_ecp_keypair_init( ecp );
/* Load the group. */
grp_id = mbedtls_ecc_group_of_psa( PSA_KEY_TYPE_ECC_GET_FAMILY( type ),
curve_size );
if( grp_id == MBEDTLS_ECP_DP_NONE )
{
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
status = mbedtls_to_psa_error(
mbedtls_ecp_group_load( &ecp->grp, grp_id ) );
if( status != PSA_SUCCESS )
goto exit;
/* Load the key material. */
if( PSA_KEY_TYPE_IS_PUBLIC_KEY( type ) )
{
/* Load the public value. */
status = mbedtls_to_psa_error(
mbedtls_ecp_point_read_binary( &ecp->grp, &ecp->Q,
data,
data_length ) );
if( status != PSA_SUCCESS )
goto exit;
/* Check that the point is on the curve. */
status = mbedtls_to_psa_error(
mbedtls_ecp_check_pubkey( &ecp->grp, &ecp->Q ) );
if( status != PSA_SUCCESS )
goto exit;
}
else
{
/* Load and validate the secret value. */
status = mbedtls_to_psa_error(
mbedtls_ecp_read_key( ecp->grp.id,
ecp,
data,
data_length ) );
if( status != PSA_SUCCESS )
goto exit;
}
*p_ecp = ecp;
exit:
if( status != PSA_SUCCESS )
{
mbedtls_ecp_keypair_free( ecp );
mbedtls_free( ecp );
}
return( status );
}
/** Export an ECP key to export representation
*
* \param[in] type The type of key (public/private) to export
* \param[in] ecp The internal ECP representation from which to export
* \param[out] data The buffer to export to
* \param[in] data_size The length of the buffer to export to
* \param[out] data_length The amount of bytes written to \p data
*/
static psa_status_t psa_export_ecp_key( psa_key_type_t type,
mbedtls_ecp_keypair *ecp,
uint8_t *data,
size_t data_size,
size_t *data_length )
{
psa_status_t status;
if( PSA_KEY_TYPE_IS_PUBLIC_KEY( type ) )
{
/* Check whether the public part is loaded */
if( mbedtls_ecp_is_zero( &ecp->Q ) )
{
/* Calculate the public key */
status = mbedtls_to_psa_error(
mbedtls_ecp_mul( &ecp->grp, &ecp->Q, &ecp->d, &ecp->grp.G,
mbedtls_ctr_drbg_random, &global_data.ctr_drbg ) );
if( status != PSA_SUCCESS )
return( status );
}
status = mbedtls_to_psa_error(
mbedtls_ecp_point_write_binary( &ecp->grp, &ecp->Q,
MBEDTLS_ECP_PF_UNCOMPRESSED,
data_length,
data,
data_size ) );
if( status != PSA_SUCCESS )
memset( data, 0, data_size );
return( status );
}
else
{
if( data_size < PSA_BITS_TO_BYTES( ecp->grp.nbits ) )
return( PSA_ERROR_BUFFER_TOO_SMALL );
status = mbedtls_to_psa_error(
mbedtls_ecp_write_key( ecp,
data,
PSA_BITS_TO_BYTES( ecp->grp.nbits ) ) );
if( status == PSA_SUCCESS )
*data_length = PSA_BITS_TO_BYTES( ecp->grp.nbits );
else
memset( data, 0, data_size );
return( status );
}
}
/** Import an ECP key from import representation to a slot
*
* \param[in,out] slot The slot where to store the export representation to
* \param[in] data The buffer containing the import representation
* \param[in] data_length The amount of bytes in \p data
*/
static psa_status_t psa_import_ecp_key( psa_key_slot_t *slot,
const uint8_t *data,
size_t data_length )
{
psa_status_t status;
uint8_t* output = NULL;
mbedtls_ecp_keypair *ecp = NULL;
/* Parse input */
status = psa_load_ecp_representation( slot->attr.type,
data,
data_length,
&ecp );
if( status != PSA_SUCCESS )
goto exit;
if( PSA_KEY_TYPE_ECC_GET_FAMILY( slot->attr.type ) == PSA_ECC_FAMILY_MONTGOMERY)
slot->attr.bits = (psa_key_bits_t) ecp->grp.nbits + 1;
else
slot->attr.bits = (psa_key_bits_t) ecp->grp.nbits;
/* Re-export the data to PSA export format. There is currently no support
* for other input formats then the export format, so this is a 1-1
* copy operation. */
output = mbedtls_calloc( 1, data_length );
if( output == NULL )
{
status = PSA_ERROR_INSUFFICIENT_MEMORY;
goto exit;
}
status = psa_export_ecp_key( slot->attr.type,
ecp,
output,
data_length,
&data_length);
exit:
/* Always free the PK object (will also free contained ECP context) */
mbedtls_ecp_keypair_free( ecp );
mbedtls_free( ecp );
/* Free the allocated buffer only on error. */
if( status != PSA_SUCCESS )
{
mbedtls_free( output );
return( status );
}
/* On success, store the allocated export-formatted key. */
slot->data.key.data = output;
slot->data.key.bytes = data_length;
return( PSA_SUCCESS );
}
#endif /* defined(MBEDTLS_ECP_C) */
/** Return the size of the key in the given slot, in bits.
*
* \param[in] slot A key slot.
*
* \return The key size in bits, read from the metadata in the slot.
*/
static inline size_t psa_get_key_slot_bits( const psa_key_slot_t *slot )
{
return( slot->attr.bits );
}
/** Try to allocate a buffer to an empty key slot.
*
* \param[in,out] slot Key slot to attach buffer to.
* \param[in] buffer_length Requested size of the buffer.
*
* \retval #PSA_SUCCESS
* The buffer has been successfully allocated.
* \retval #PSA_ERROR_INSUFFICIENT_MEMORY
* Not enough memory was available for allocation.
* \retval #PSA_ERROR_ALREADY_EXISTS
* Trying to allocate a buffer to a non-empty key slot.
*/
static psa_status_t psa_allocate_buffer_to_slot( psa_key_slot_t *slot,
size_t buffer_length )
{
if( slot->data.key.data != NULL )
return( PSA_ERROR_ALREADY_EXISTS );
slot->data.key.data = mbedtls_calloc( 1, buffer_length );
if( slot->data.key.data == NULL )
return( PSA_ERROR_INSUFFICIENT_MEMORY );
slot->data.key.bytes = buffer_length;
return( PSA_SUCCESS );
}
/** Import key data into a slot. `slot->attr.type` must have been set
* previously. This function assumes that the slot does not contain
* any key material yet. On failure, the slot content is unchanged. */
psa_status_t psa_import_key_into_slot( psa_key_slot_t *slot,
const uint8_t *data,
size_t data_length )
{
psa_status_t status = PSA_SUCCESS;
/* zero-length keys are never supported. */
if( data_length == 0 )
return( PSA_ERROR_NOT_SUPPORTED );
if( key_type_is_raw_bytes( slot->attr.type ) )
{
size_t bit_size = PSA_BYTES_TO_BITS( data_length );
/* Ensure that the bytes-to-bits conversion hasn't overflown. */
if( data_length > SIZE_MAX / 8 )
return( PSA_ERROR_NOT_SUPPORTED );
/* Enforce a size limit, and in particular ensure that the bit
* size fits in its representation type. */
if( bit_size > PSA_MAX_KEY_BITS )
return( PSA_ERROR_NOT_SUPPORTED );
status = validate_unstructured_key_bit_size( slot->attr.type, bit_size );
if( status != PSA_SUCCESS )
return( status );
/* Allocate memory for the key */
status = psa_allocate_buffer_to_slot( slot, data_length );
if( status != PSA_SUCCESS )
return( status );
/* copy key into allocated buffer */
memcpy( slot->data.key.data, data, data_length );
/* Write the actual key size to the slot.
* psa_start_key_creation() wrote the size declared by the
* caller, which may be 0 (meaning unspecified) or wrong. */
slot->attr.bits = (psa_key_bits_t) bit_size;
}
else if( PSA_KEY_TYPE_IS_ECC( slot->attr.type ) )
{
#if defined(MBEDTLS_ECP_C)
status = psa_import_ecp_key( slot,
data, data_length );
#else
/* No drivers have been implemented yet, so without mbed TLS backing
* there's no way to do ECP with the current library. */
return( PSA_ERROR_NOT_SUPPORTED );
#endif /* defined(MBEDTLS_ECP_C) */
}
else if( PSA_KEY_TYPE_IS_RSA( slot->attr.type ) )
{
#if defined(MBEDTLS_RSA_C)
status = psa_import_rsa_key( slot,
data, data_length );
#else
/* No drivers have been implemented yet, so without mbed TLS backing
* there's no way to do RSA with the current library. */
status = PSA_ERROR_NOT_SUPPORTED;
#endif /* defined(MBEDTLS_RSA_C) */
}
else
{
/* Unknown key type */
return( PSA_ERROR_NOT_SUPPORTED );
}
return( status );
}
/** Calculate the intersection of two algorithm usage policies.
*
* Return 0 (which allows no operation) on incompatibility.
*/
static psa_algorithm_t psa_key_policy_algorithm_intersection(
psa_algorithm_t alg1,
psa_algorithm_t alg2 )
{
/* Common case: both sides actually specify the same policy. */
if( alg1 == alg2 )
return( alg1 );
/* If the policies are from the same hash-and-sign family, check
* if one is a wildcard. If so the other has the specific algorithm. */
if( PSA_ALG_IS_HASH_AND_SIGN( alg1 ) &&
PSA_ALG_IS_HASH_AND_SIGN( alg2 ) &&
( alg1 & ~PSA_ALG_HASH_MASK ) == ( alg2 & ~PSA_ALG_HASH_MASK ) )
{
if( PSA_ALG_SIGN_GET_HASH( alg1 ) == PSA_ALG_ANY_HASH )
return( alg2 );
if( PSA_ALG_SIGN_GET_HASH( alg2 ) == PSA_ALG_ANY_HASH )
return( alg1 );
}
/* If the policies are incompatible, allow nothing. */
return( 0 );
}
static int psa_key_algorithm_permits( psa_algorithm_t policy_alg,
psa_algorithm_t requested_alg )
{
/* Common case: the policy only allows requested_alg. */
if( requested_alg == policy_alg )
return( 1 );
/* If policy_alg is a hash-and-sign with a wildcard for the hash,
* and requested_alg is the same hash-and-sign family with any hash,
* then requested_alg is compliant with policy_alg. */
if( PSA_ALG_IS_HASH_AND_SIGN( requested_alg ) &&
PSA_ALG_SIGN_GET_HASH( policy_alg ) == PSA_ALG_ANY_HASH )
{
return( ( policy_alg & ~PSA_ALG_HASH_MASK ) ==
( requested_alg & ~PSA_ALG_HASH_MASK ) );
}
/* If policy_alg is a generic key agreement operation, then using it for
* a key derivation with that key agreement should also be allowed. This
* behaviour is expected to be defined in a future specification version. */
if( PSA_ALG_IS_RAW_KEY_AGREEMENT( policy_alg ) &&
PSA_ALG_IS_KEY_AGREEMENT( requested_alg ) )
{
return( PSA_ALG_KEY_AGREEMENT_GET_BASE( requested_alg ) ==
policy_alg );
}
/* If it isn't permitted, it's forbidden. */
return( 0 );
}
/** Test whether a policy permits an algorithm.
*
* The caller must test usage flags separately.
*/
static int psa_key_policy_permits( const psa_key_policy_t *policy,
psa_algorithm_t alg )
{
return( psa_key_algorithm_permits( policy->alg, alg ) ||
psa_key_algorithm_permits( policy->alg2, alg ) );
}
/** Restrict a key policy based on a constraint.
*
* \param[in,out] policy The policy to restrict.
* \param[in] constraint The policy constraint to apply.
*
* \retval #PSA_SUCCESS
* \c *policy contains the intersection of the original value of
* \c *policy and \c *constraint.
* \retval #PSA_ERROR_INVALID_ARGUMENT
* \c *policy and \c *constraint are incompatible.
* \c *policy is unchanged.
*/
static psa_status_t psa_restrict_key_policy(
psa_key_policy_t *policy,
const psa_key_policy_t *constraint )
{
psa_algorithm_t intersection_alg =
psa_key_policy_algorithm_intersection( policy->alg, constraint->alg );
psa_algorithm_t intersection_alg2 =
psa_key_policy_algorithm_intersection( policy->alg2, constraint->alg2 );
if( intersection_alg == 0 && policy->alg != 0 && constraint->alg != 0 )
return( PSA_ERROR_INVALID_ARGUMENT );
if( intersection_alg2 == 0 && policy->alg2 != 0 && constraint->alg2 != 0 )
return( PSA_ERROR_INVALID_ARGUMENT );
policy->usage &= constraint->usage;
policy->alg = intersection_alg;
policy->alg2 = intersection_alg2;
return( PSA_SUCCESS );
}
/** Retrieve a slot which must contain a key. The key must have allow all the
* usage flags set in \p usage. If \p alg is nonzero, the key must allow
* operations with this algorithm. */
static psa_status_t psa_get_key_from_slot( psa_key_handle_t handle,
psa_key_slot_t **p_slot,
psa_key_usage_t usage,
psa_algorithm_t alg )
{
psa_status_t status;
psa_key_slot_t *slot = NULL;
*p_slot = NULL;
status = psa_get_key_slot( handle, &slot );
if( status != PSA_SUCCESS )
return( status );
/* Enforce that usage policy for the key slot contains all the flags
* required by the usage parameter. There is one exception: public
* keys can always be exported, so we treat public key objects as
* if they had the export flag. */
if( PSA_KEY_TYPE_IS_PUBLIC_KEY( slot->attr.type ) )
usage &= ~PSA_KEY_USAGE_EXPORT;
if( ( slot->attr.policy.usage & usage ) != usage )
return( PSA_ERROR_NOT_PERMITTED );
/* Enforce that the usage policy permits the requested algortihm. */
if( alg != 0 && ! psa_key_policy_permits( &slot->attr.policy, alg ) )
return( PSA_ERROR_NOT_PERMITTED );
*p_slot = slot;
return( PSA_SUCCESS );
}
/** Retrieve a slot which must contain a transparent key.
*
* A transparent key is a key for which the key material is directly
* available, as opposed to a key in a secure element.
*
* This is a temporary function to use instead of psa_get_key_from_slot()
* until secure element support is fully implemented.
*/
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
static psa_status_t psa_get_transparent_key( psa_key_handle_t handle,
psa_key_slot_t **p_slot,
psa_key_usage_t usage,
psa_algorithm_t alg )
{
psa_status_t status = psa_get_key_from_slot( handle, p_slot, usage, alg );
if( status != PSA_SUCCESS )
return( status );
if( psa_key_slot_is_external( *p_slot ) )
{
*p_slot = NULL;
return( PSA_ERROR_NOT_SUPPORTED );
}
return( PSA_SUCCESS );
}
#else /* MBEDTLS_PSA_CRYPTO_SE_C */
/* With no secure element support, all keys are transparent. */
#define psa_get_transparent_key( handle, p_slot, usage, alg ) \
psa_get_key_from_slot( handle, p_slot, usage, alg )
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
/** Wipe key data from a slot. Preserve metadata such as the policy. */
static psa_status_t psa_remove_key_data_from_memory( psa_key_slot_t *slot )
{
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
if( psa_key_slot_is_external( slot ) )
{
/* No key material to clean. */
}
else
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
{
/* Data pointer will always be either a valid pointer or NULL in an
* initialized slot, so we can just free it. */
if( slot->data.key.data != NULL )
mbedtls_platform_zeroize( slot->data.key.data, slot->data.key.bytes);
mbedtls_free( slot->data.key.data );
slot->data.key.data = NULL;
slot->data.key.bytes = 0;
}
return( PSA_SUCCESS );
}
/** Completely wipe a slot in memory, including its policy.
* Persistent storage is not affected. */
psa_status_t psa_wipe_key_slot( psa_key_slot_t *slot )
{
psa_status_t status = psa_remove_key_data_from_memory( slot );
/* Multipart operations may still be using the key. This is safe
* because all multipart operation objects are independent from
* the key slot: if they need to access the key after the setup
* phase, they have a copy of the key. Note that this means that
* key material can linger until all operations are completed. */
/* At this point, key material and other type-specific content has
* been wiped. Clear remaining metadata. We can call memset and not
* zeroize because the metadata is not particularly sensitive. */
memset( slot, 0, sizeof( *slot ) );
return( status );
}
psa_status_t psa_destroy_key( psa_key_handle_t handle )
{
psa_key_slot_t *slot;
psa_status_t status; /* status of the last operation */
psa_status_t overall_status = PSA_SUCCESS;
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
psa_se_drv_table_entry_t *driver;
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
if( handle == 0 )
return( PSA_SUCCESS );
status = psa_get_key_slot( handle, &slot );
if( status != PSA_SUCCESS )
return( status );
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
driver = psa_get_se_driver_entry( slot->attr.lifetime );
if( driver != NULL )
{
/* For a key in a secure element, we need to do three things:
* remove the key file in internal storage, destroy the
* key inside the secure element, and update the driver's
* persistent data. Start a transaction that will encompass these
* three actions. */
psa_crypto_prepare_transaction( PSA_CRYPTO_TRANSACTION_DESTROY_KEY );
psa_crypto_transaction.key.lifetime = slot->attr.lifetime;
psa_crypto_transaction.key.slot = slot->data.se.slot_number;
psa_crypto_transaction.key.id = slot->attr.id;
status = psa_crypto_save_transaction( );
if( status != PSA_SUCCESS )
{
(void) psa_crypto_stop_transaction( );
/* We should still try to destroy the key in the secure
* element and the key metadata in storage. This is especially
* important if the error is that the storage is full.
* But how to do it exactly without risking an inconsistent
* state after a reset?
* https://github.com/ARMmbed/mbed-crypto/issues/215
*/
overall_status = status;
goto exit;
}
status = psa_destroy_se_key( driver, slot->data.se.slot_number );
if( overall_status == PSA_SUCCESS )
overall_status = status;
}
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
#if defined(MBEDTLS_PSA_CRYPTO_STORAGE_C)
if( slot->attr.lifetime != PSA_KEY_LIFETIME_VOLATILE )
{
status = psa_destroy_persistent_key( slot->attr.id );
if( overall_status == PSA_SUCCESS )
overall_status = status;
/* TODO: other slots may have a copy of the same key. We should
* invalidate them.
* https://github.com/ARMmbed/mbed-crypto/issues/214
*/
}
#endif /* defined(MBEDTLS_PSA_CRYPTO_STORAGE_C) */
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
if( driver != NULL )
{
status = psa_save_se_persistent_data( driver );
if( overall_status == PSA_SUCCESS )
overall_status = status;
status = psa_crypto_stop_transaction( );
if( overall_status == PSA_SUCCESS )
overall_status = status;
}
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
exit:
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
status = psa_wipe_key_slot( slot );
/* Prioritize CORRUPTION_DETECTED from wiping over a storage error */
if( overall_status == PSA_SUCCESS )
overall_status = status;
return( overall_status );
}
void psa_reset_key_attributes( psa_key_attributes_t *attributes )
{
mbedtls_free( attributes->domain_parameters );
memset( attributes, 0, sizeof( *attributes ) );
}
psa_status_t psa_set_key_domain_parameters( psa_key_attributes_t *attributes,
psa_key_type_t type,
const uint8_t *data,
size_t data_length )
{
uint8_t *copy = NULL;
if( data_length != 0 )
{
copy = mbedtls_calloc( 1, data_length );
if( copy == NULL )
return( PSA_ERROR_INSUFFICIENT_MEMORY );
memcpy( copy, data, data_length );
}
/* After this point, this function is guaranteed to succeed, so it
* can start modifying `*attributes`. */
if( attributes->domain_parameters != NULL )
{
mbedtls_free( attributes->domain_parameters );
attributes->domain_parameters = NULL;
attributes->domain_parameters_size = 0;
}
attributes->domain_parameters = copy;
attributes->domain_parameters_size = data_length;
attributes->core.type = type;
return( PSA_SUCCESS );
}
psa_status_t psa_get_key_domain_parameters(
const psa_key_attributes_t *attributes,
uint8_t *data, size_t data_size, size_t *data_length )
{
if( attributes->domain_parameters_size > data_size )
return( PSA_ERROR_BUFFER_TOO_SMALL );
*data_length = attributes->domain_parameters_size;
if( attributes->domain_parameters_size != 0 )
memcpy( data, attributes->domain_parameters,
attributes->domain_parameters_size );
return( PSA_SUCCESS );
}
#if defined(MBEDTLS_RSA_C)
static psa_status_t psa_get_rsa_public_exponent(
const mbedtls_rsa_context *rsa,
psa_key_attributes_t *attributes )
{
mbedtls_mpi mpi;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
uint8_t *buffer = NULL;
size_t buflen;
mbedtls_mpi_init( &mpi );
ret = mbedtls_rsa_export( rsa, NULL, NULL, NULL, NULL, &mpi );
if( ret != 0 )
goto exit;
if( mbedtls_mpi_cmp_int( &mpi, 65537 ) == 0 )
{
/* It's the default value, which is reported as an empty string,
* so there's nothing to do. */
goto exit;
}
buflen = mbedtls_mpi_size( &mpi );
buffer = mbedtls_calloc( 1, buflen );
if( buffer == NULL )
{
ret = MBEDTLS_ERR_MPI_ALLOC_FAILED;
goto exit;
}
ret = mbedtls_mpi_write_binary( &mpi, buffer, buflen );
if( ret != 0 )
goto exit;
attributes->domain_parameters = buffer;
attributes->domain_parameters_size = buflen;
exit:
mbedtls_mpi_free( &mpi );
if( ret != 0 )
mbedtls_free( buffer );
return( mbedtls_to_psa_error( ret ) );
}
#endif /* MBEDTLS_RSA_C */
/** Retrieve all the publicly-accessible attributes of a key.
*/
psa_status_t psa_get_key_attributes( psa_key_handle_t handle,
psa_key_attributes_t *attributes )
{
psa_key_slot_t *slot;
psa_status_t status;
psa_reset_key_attributes( attributes );
status = psa_get_key_from_slot( handle, &slot, 0, 0 );
if( status != PSA_SUCCESS )
return( status );
attributes->core = slot->attr;
attributes->core.flags &= ( MBEDTLS_PSA_KA_MASK_EXTERNAL_ONLY |
MBEDTLS_PSA_KA_MASK_DUAL_USE );
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
if( psa_key_slot_is_external( slot ) )
psa_set_key_slot_number( attributes, slot->data.se.slot_number );
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
switch( slot->attr.type )
{
#if defined(MBEDTLS_RSA_C)
case PSA_KEY_TYPE_RSA_KEY_PAIR:
case PSA_KEY_TYPE_RSA_PUBLIC_KEY:
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
/* TODO: reporting the public exponent for opaque keys
* is not yet implemented.
* https://github.com/ARMmbed/mbed-crypto/issues/216
*/
if( psa_key_slot_is_external( slot ) )
break;
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
{
mbedtls_rsa_context *rsa = NULL;
status = psa_load_rsa_representation( slot->attr.type,
slot->data.key.data,
slot->data.key.bytes,
&rsa );
if( status != PSA_SUCCESS )
break;
status = psa_get_rsa_public_exponent( rsa,
attributes );
mbedtls_rsa_free( rsa );
mbedtls_free( rsa );
}
break;
#endif /* MBEDTLS_RSA_C */
default:
/* Nothing else to do. */
break;
}
if( status != PSA_SUCCESS )
psa_reset_key_attributes( attributes );
return( status );
}
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
psa_status_t psa_get_key_slot_number(
const psa_key_attributes_t *attributes,
psa_key_slot_number_t *slot_number )
{
if( attributes->core.flags & MBEDTLS_PSA_KA_FLAG_HAS_SLOT_NUMBER )
{
*slot_number = attributes->slot_number;
return( PSA_SUCCESS );
}
else
return( PSA_ERROR_INVALID_ARGUMENT );
}
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
static psa_status_t psa_internal_export_key_buffer( const psa_key_slot_t *slot,
uint8_t *data,
size_t data_size,
size_t *data_length )
{
if( slot->data.key.bytes > data_size )
return( PSA_ERROR_BUFFER_TOO_SMALL );
memcpy( data, slot->data.key.data, slot->data.key.bytes );
memset( data + slot->data.key.bytes, 0,
data_size - slot->data.key.bytes );
*data_length = slot->data.key.bytes;
return( PSA_SUCCESS );
}
static psa_status_t psa_internal_export_key( const psa_key_slot_t *slot,
uint8_t *data,
size_t data_size,
size_t *data_length,
int export_public_key )
{
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
const psa_drv_se_t *drv;
psa_drv_se_context_t *drv_context;
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
*data_length = 0;
if( export_public_key && ! PSA_KEY_TYPE_IS_ASYMMETRIC( slot->attr.type ) )
return( PSA_ERROR_INVALID_ARGUMENT );
/* Reject a zero-length output buffer now, since this can never be a
* valid key representation. This way we know that data must be a valid
* pointer and we can do things like memset(data, ..., data_size). */
if( data_size == 0 )
return( PSA_ERROR_BUFFER_TOO_SMALL );
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
if( psa_get_se_driver( slot->attr.lifetime, &drv, &drv_context ) )
{
psa_drv_se_export_key_t method;
if( drv->key_management == NULL )
return( PSA_ERROR_NOT_SUPPORTED );
method = ( export_public_key ?
drv->key_management->p_export_public :
drv->key_management->p_export );
if( method == NULL )
return( PSA_ERROR_NOT_SUPPORTED );
return( method( drv_context,
slot->data.se.slot_number,
data, data_size, data_length ) );
}
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
if( key_type_is_raw_bytes( slot->attr.type ) )
{
return( psa_internal_export_key_buffer( slot, data, data_size, data_length ) );
}
else if( PSA_KEY_TYPE_IS_RSA( slot->attr.type ) ||
PSA_KEY_TYPE_IS_ECC( slot->attr.type ) )
{
if( PSA_KEY_TYPE_IS_PUBLIC_KEY( slot->attr.type ) )
{
/* Exporting public -> public */
return( psa_internal_export_key_buffer( slot, data, data_size, data_length ) );
}
else if( !export_public_key )
{
/* Exporting private -> private */
return( psa_internal_export_key_buffer( slot, data, data_size, data_length ) );
}
/* Need to export the public part of a private key,
* so conversion is needed */
if( PSA_KEY_TYPE_IS_RSA( slot->attr.type ) )
{
#if defined(MBEDTLS_RSA_C)
mbedtls_rsa_context *rsa = NULL;
psa_status_t status = psa_load_rsa_representation(
slot->attr.type,
slot->data.key.data,
slot->data.key.bytes,
&rsa );
if( status != PSA_SUCCESS )
return( status );
status = psa_export_rsa_key( PSA_KEY_TYPE_RSA_PUBLIC_KEY,
rsa,
data,
data_size,
data_length );
mbedtls_rsa_free( rsa );
mbedtls_free( rsa );
return( status );
#else
/* We don't know how to convert a private RSA key to public. */
return( PSA_ERROR_NOT_SUPPORTED );
#endif
}
else
{
#if defined(MBEDTLS_ECP_C)
mbedtls_ecp_keypair *ecp = NULL;
psa_status_t status = psa_load_ecp_representation(
slot->attr.type,
slot->data.key.data,
slot->data.key.bytes,
&ecp );
if( status != PSA_SUCCESS )
return( status );
status = psa_export_ecp_key( PSA_KEY_TYPE_ECC_PUBLIC_KEY(
PSA_KEY_TYPE_ECC_GET_FAMILY(
slot->attr.type ) ),
ecp,
data,
data_size,
data_length );
mbedtls_ecp_keypair_free( ecp );
mbedtls_free( ecp );
return( status );
#else
/* We don't know how to convert a private ECC key to public */
return( PSA_ERROR_NOT_SUPPORTED );
#endif
}
}
else
{
/* This shouldn't happen in the reference implementation, but
it is valid for a special-purpose implementation to omit
support for exporting certain key types. */
return( PSA_ERROR_NOT_SUPPORTED );
}
}
psa_status_t psa_export_key( psa_key_handle_t handle,
uint8_t *data,
size_t data_size,
size_t *data_length )
{
psa_key_slot_t *slot;
psa_status_t status;
/* Set the key to empty now, so that even when there are errors, we always
* set data_length to a value between 0 and data_size. On error, setting
* the key to empty is a good choice because an empty key representation is
* unlikely to be accepted anywhere. */
*data_length = 0;
/* Export requires the EXPORT flag. There is an exception for public keys,
* which don't require any flag, but psa_get_key_from_slot takes
* care of this. */
status = psa_get_key_from_slot( handle, &slot, PSA_KEY_USAGE_EXPORT, 0 );
if( status != PSA_SUCCESS )
return( status );
return( psa_internal_export_key( slot, data, data_size,
data_length, 0 ) );
}
psa_status_t psa_export_public_key( psa_key_handle_t handle,
uint8_t *data,
size_t data_size,
size_t *data_length )
{
psa_key_slot_t *slot;
psa_status_t status;
/* Set the key to empty now, so that even when there are errors, we always
* set data_length to a value between 0 and data_size. On error, setting
* the key to empty is a good choice because an empty key representation is
* unlikely to be accepted anywhere. */
*data_length = 0;
/* Exporting a public key doesn't require a usage flag. */
status = psa_get_key_from_slot( handle, &slot, 0, 0 );
if( status != PSA_SUCCESS )
return( status );
return( psa_internal_export_key( slot, data, data_size,
data_length, 1 ) );
}
#if defined(static_assert)
static_assert( ( MBEDTLS_PSA_KA_MASK_EXTERNAL_ONLY & MBEDTLS_PSA_KA_MASK_DUAL_USE ) == 0,
"One or more key attribute flag is listed as both external-only and dual-use" );
static_assert( ( PSA_KA_MASK_INTERNAL_ONLY & MBEDTLS_PSA_KA_MASK_DUAL_USE ) == 0,
"One or more key attribute flag is listed as both internal-only and dual-use" );
static_assert( ( PSA_KA_MASK_INTERNAL_ONLY & MBEDTLS_PSA_KA_MASK_EXTERNAL_ONLY ) == 0,
"One or more key attribute flag is listed as both internal-only and external-only" );
#endif
/** Validate that a key policy is internally well-formed.
*
* This function only rejects invalid policies. It does not validate the
* consistency of the policy with respect to other attributes of the key
* such as the key type.
*/
static psa_status_t psa_validate_key_policy( const psa_key_policy_t *policy )
{
if( ( policy->usage & ~( PSA_KEY_USAGE_EXPORT |
PSA_KEY_USAGE_COPY |
PSA_KEY_USAGE_ENCRYPT |
PSA_KEY_USAGE_DECRYPT |
PSA_KEY_USAGE_SIGN_HASH |
PSA_KEY_USAGE_VERIFY_HASH |
PSA_KEY_USAGE_DERIVE ) ) != 0 )
return( PSA_ERROR_INVALID_ARGUMENT );
return( PSA_SUCCESS );
}
/** Validate the internal consistency of key attributes.
*
* This function only rejects invalid attribute values. If does not
* validate the consistency of the attributes with any key data that may
* be involved in the creation of the key.
*
* Call this function early in the key creation process.
*
* \param[in] attributes Key attributes for the new key.
* \param[out] p_drv On any return, the driver for the key, if any.
* NULL for a transparent key.
*
*/
static psa_status_t psa_validate_key_attributes(
const psa_key_attributes_t *attributes,
psa_se_drv_table_entry_t **p_drv )
{
psa_status_t status = PSA_ERROR_INVALID_ARGUMENT;
status = psa_validate_key_location( psa_get_key_lifetime( attributes ),
p_drv );
if( status != PSA_SUCCESS )
return( status );
status = psa_validate_key_persistence( psa_get_key_lifetime( attributes ),
psa_get_key_id( attributes ) );
if( status != PSA_SUCCESS )
return( status );
status = psa_validate_key_policy( &attributes->core.policy );
if( status != PSA_SUCCESS )
return( status );
/* Refuse to create overly large keys.
* Note that this doesn't trigger on import if the attributes don't
* explicitly specify a size (so psa_get_key_bits returns 0), so
* psa_import_key() needs its own checks. */
if( psa_get_key_bits( attributes ) > PSA_MAX_KEY_BITS )
return( PSA_ERROR_NOT_SUPPORTED );
/* Reject invalid flags. These should not be reachable through the API. */
if( attributes->core.flags & ~ ( MBEDTLS_PSA_KA_MASK_EXTERNAL_ONLY |
MBEDTLS_PSA_KA_MASK_DUAL_USE ) )
return( PSA_ERROR_INVALID_ARGUMENT );
return( PSA_SUCCESS );
}
/** Prepare a key slot to receive key material.
*
* This function allocates a key slot and sets its metadata.
*
* If this function fails, call psa_fail_key_creation().
*
* This function is intended to be used as follows:
* -# Call psa_start_key_creation() to allocate a key slot, prepare
* it with the specified attributes, and assign it a handle.
* -# Populate the slot with the key material.
* -# Call psa_finish_key_creation() to finalize the creation of the slot.
* In case of failure at any step, stop the sequence and call
* psa_fail_key_creation().
*
* \param method An identification of the calling function.
* \param[in] attributes Key attributes for the new key.
* \param[out] handle On success, a handle for the allocated slot.
* \param[out] p_slot On success, a pointer to the prepared slot.
* \param[out] p_drv On any return, the driver for the key, if any.
* NULL for a transparent key.
*
* \retval #PSA_SUCCESS
* The key slot is ready to receive key material.
* \return If this function fails, the key slot is an invalid state.
* You must call psa_fail_key_creation() to wipe and free the slot.
*/
static psa_status_t psa_start_key_creation(
psa_key_creation_method_t method,
const psa_key_attributes_t *attributes,
psa_key_handle_t *handle,
psa_key_slot_t **p_slot,
psa_se_drv_table_entry_t **p_drv )
{
psa_status_t status;
psa_key_slot_t *slot;
(void) method;
*p_drv = NULL;
status = psa_validate_key_attributes( attributes, p_drv );
if( status != PSA_SUCCESS )
return( status );
status = psa_get_empty_key_slot( handle, p_slot );
if( status != PSA_SUCCESS )
return( status );
slot = *p_slot;
/* We're storing the declared bit-size of the key. It's up to each
* creation mechanism to verify that this information is correct.
* It's automatically correct for mechanisms that use the bit-size as
* an input (generate, device) but not for those where the bit-size
* is optional (import, copy). */
slot->attr = attributes->core;
/* Erase external-only flags from the internal copy. To access
* external-only flags, query `attributes`. Thanks to the check
* in psa_validate_key_attributes(), this leaves the dual-use
* flags and any internal flag that psa_get_empty_key_slot()
* may have set. */
slot->attr.flags &= ~MBEDTLS_PSA_KA_MASK_EXTERNAL_ONLY;
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
/* For a key in a secure element, we need to do three things
* when creating or registering a persistent key:
* create the key file in internal storage, create the
* key inside the secure element, and update the driver's
* persistent data. This is done by starting a transaction that will
* encompass these three actions.
* For registering a volatile key, we just need to find an appropriate
* slot number inside the SE. Since the key is designated volatile, creating
* a transaction is not required. */
/* The first thing to do is to find a slot number for the new key.
* We save the slot number in persistent storage as part of the
* transaction data. It will be needed to recover if the power
* fails during the key creation process, to clean up on the secure
* element side after restarting. Obtaining a slot number from the
* secure element driver updates its persistent state, but we do not yet
* save the driver's persistent state, so that if the power fails,
* we can roll back to a state where the key doesn't exist. */
if( *p_drv != NULL )
{
status = psa_find_se_slot_for_key( attributes, method, *p_drv,
&slot->data.se.slot_number );
if( status != PSA_SUCCESS )
return( status );
if( ! PSA_KEY_LIFETIME_IS_VOLATILE( attributes->core.lifetime ) )
{
psa_crypto_prepare_transaction( PSA_CRYPTO_TRANSACTION_CREATE_KEY );
psa_crypto_transaction.key.lifetime = slot->attr.lifetime;
psa_crypto_transaction.key.slot = slot->data.se.slot_number;
psa_crypto_transaction.key.id = slot->attr.id;
status = psa_crypto_save_transaction( );
if( status != PSA_SUCCESS )
{
(void) psa_crypto_stop_transaction( );
return( status );
}
}
}
if( *p_drv == NULL && method == PSA_KEY_CREATION_REGISTER )
{
/* Key registration only makes sense with a secure element. */
return( PSA_ERROR_INVALID_ARGUMENT );
}
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
return( status );
}
/** Finalize the creation of a key once its key material has been set.
*
* This entails writing the key to persistent storage.
*
* If this function fails, call psa_fail_key_creation().
* See the documentation of psa_start_key_creation() for the intended use
* of this function.
*
* \param[in,out] slot Pointer to the slot with key material.
* \param[in] driver The secure element driver for the key,
* or NULL for a transparent key.
*
* \retval #PSA_SUCCESS
* The key was successfully created. The handle is now valid.
* \return If this function fails, the key slot is an invalid state.
* You must call psa_fail_key_creation() to wipe and free the slot.
*/
static psa_status_t psa_finish_key_creation(
psa_key_slot_t *slot,
psa_se_drv_table_entry_t *driver )
{
psa_status_t status = PSA_SUCCESS;
(void) slot;
(void) driver;
#if defined(MBEDTLS_PSA_CRYPTO_STORAGE_C)
if( ! PSA_KEY_LIFETIME_IS_VOLATILE( slot->attr.lifetime ) )
{
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
if( driver != NULL )
{
psa_se_key_data_storage_t data;
#if defined(static_assert)
static_assert( sizeof( slot->data.se.slot_number ) ==
sizeof( data.slot_number ),
"Slot number size does not match psa_se_key_data_storage_t" );
#endif
memcpy( &data.slot_number, &slot->data.se.slot_number,
sizeof( slot->data.se.slot_number ) );
status = psa_save_persistent_key( &slot->attr,
(uint8_t*) &data,
sizeof( data ) );
}
else
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
{
size_t buffer_size =
PSA_KEY_EXPORT_MAX_SIZE( slot->attr.type,
slot->attr.bits );
uint8_t *buffer = mbedtls_calloc( 1, buffer_size );
size_t length = 0;
if( buffer == NULL )
return( PSA_ERROR_INSUFFICIENT_MEMORY );
status = psa_internal_export_key( slot,
buffer, buffer_size, &length,
0 );
if( status == PSA_SUCCESS )
status = psa_save_persistent_key( &slot->attr,
buffer, length );
mbedtls_platform_zeroize( buffer, buffer_size );
mbedtls_free( buffer );
}
}
#endif /* defined(MBEDTLS_PSA_CRYPTO_STORAGE_C) */
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
/* Finish the transaction for a key creation. This does not
* happen when registering an existing key. Detect this case
* by checking whether a transaction is in progress (actual
* creation of a persistent key in a secure element requires a transaction,
* but registration or volatile key creation doesn't use one). */
if( driver != NULL &&
psa_crypto_transaction.unknown.type == PSA_CRYPTO_TRANSACTION_CREATE_KEY )
{
status = psa_save_se_persistent_data( driver );
if( status != PSA_SUCCESS )
{
psa_destroy_persistent_key( slot->attr.id );
return( status );
}
status = psa_crypto_stop_transaction( );
if( status != PSA_SUCCESS )
return( status );
}
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
return( status );
}
/** Abort the creation of a key.
*
* You may call this function after calling psa_start_key_creation(),
* or after psa_finish_key_creation() fails. In other circumstances, this
* function may not clean up persistent storage.
* See the documentation of psa_start_key_creation() for the intended use
* of this function.
*
* \param[in,out] slot Pointer to the slot with key material.
* \param[in] driver The secure element driver for the key,
* or NULL for a transparent key.
*/
static void psa_fail_key_creation( psa_key_slot_t *slot,
psa_se_drv_table_entry_t *driver )
{
(void) driver;
if( slot == NULL )
return;
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
/* TODO: If the key has already been created in the secure
* element, and the failure happened later (when saving metadata
* to internal storage), we need to destroy the key in the secure
* element.
* https://github.com/ARMmbed/mbed-crypto/issues/217
*/
/* Abort the ongoing transaction if any (there may not be one if
* the creation process failed before starting one, or if the
* key creation is a registration of a key in a secure element).
* Earlier functions must already have done what it takes to undo any
* partial creation. All that's left is to update the transaction data
* itself. */
(void) psa_crypto_stop_transaction( );
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
psa_wipe_key_slot( slot );
}
/** Validate optional attributes during key creation.
*
* Some key attributes are optional during key creation. If they are
* specified in the attributes structure, check that they are consistent
* with the data in the slot.
*
* This function should be called near the end of key creation, after
* the slot in memory is fully populated but before saving persistent data.
*/
static psa_status_t psa_validate_optional_attributes(
const psa_key_slot_t *slot,
const psa_key_attributes_t *attributes )
{
if( attributes->core.type != 0 )
{
if( attributes->core.type != slot->attr.type )
return( PSA_ERROR_INVALID_ARGUMENT );
}
if( attributes->domain_parameters_size != 0 )
{
#if defined(MBEDTLS_RSA_C)
if( PSA_KEY_TYPE_IS_RSA( slot->attr.type ) )
{
mbedtls_rsa_context *rsa = NULL;
mbedtls_mpi actual, required;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
psa_status_t status = psa_load_rsa_representation(
slot->attr.type,
slot->data.key.data,
slot->data.key.bytes,
&rsa );
if( status != PSA_SUCCESS )
return( status );
mbedtls_mpi_init( &actual );
mbedtls_mpi_init( &required );
ret = mbedtls_rsa_export( rsa,
NULL, NULL, NULL, NULL, &actual );
mbedtls_rsa_free( rsa );
mbedtls_free( rsa );
if( ret != 0 )
goto rsa_exit;
ret = mbedtls_mpi_read_binary( &required,
attributes->domain_parameters,
attributes->domain_parameters_size );
if( ret != 0 )
goto rsa_exit;
if( mbedtls_mpi_cmp_mpi( &actual, &required ) != 0 )
ret = MBEDTLS_ERR_RSA_BAD_INPUT_DATA;
rsa_exit:
mbedtls_mpi_free( &actual );
mbedtls_mpi_free( &required );
if( ret != 0)
return( mbedtls_to_psa_error( ret ) );
}
else
#endif
{
return( PSA_ERROR_INVALID_ARGUMENT );
}
}
if( attributes->core.bits != 0 )
{
if( attributes->core.bits != slot->attr.bits )
return( PSA_ERROR_INVALID_ARGUMENT );
}
return( PSA_SUCCESS );
}
psa_status_t psa_import_key( const psa_key_attributes_t *attributes,
const uint8_t *data,
size_t data_length,
psa_key_handle_t *handle )
{
psa_status_t status;
psa_key_slot_t *slot = NULL;
psa_se_drv_table_entry_t *driver = NULL;
/* Reject zero-length symmetric keys (including raw data key objects).
* This also rejects any key which might be encoded as an empty string,
* which is never valid. */
if( data_length == 0 )
return( PSA_ERROR_INVALID_ARGUMENT );
status = psa_start_key_creation( PSA_KEY_CREATION_IMPORT, attributes,
handle, &slot, &driver );
if( status != PSA_SUCCESS )
goto exit;
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
if( driver != NULL )
{
const psa_drv_se_t *drv = psa_get_se_driver_methods( driver );
/* The driver should set the number of key bits, however in
* case it doesn't, we initialize bits to an invalid value. */
size_t bits = PSA_MAX_KEY_BITS + 1;
if( drv->key_management == NULL ||
drv->key_management->p_import == NULL )
{
status = PSA_ERROR_NOT_SUPPORTED;
goto exit;
}
status = drv->key_management->p_import(
psa_get_se_driver_context( driver ),
slot->data.se.slot_number, attributes, data, data_length,
&bits );
if( status != PSA_SUCCESS )
goto exit;
if( bits > PSA_MAX_KEY_BITS )
{
status = PSA_ERROR_NOT_SUPPORTED;
goto exit;
}
slot->attr.bits = (psa_key_bits_t) bits;
}
else
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
{
status = psa_import_key_into_slot( slot, data, data_length );
if( status != PSA_SUCCESS )
goto exit;
}
status = psa_validate_optional_attributes( slot, attributes );
if( status != PSA_SUCCESS )
goto exit;
status = psa_finish_key_creation( slot, driver );
exit:
if( status != PSA_SUCCESS )
{
psa_fail_key_creation( slot, driver );
*handle = 0;
}
return( status );
}
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
psa_status_t mbedtls_psa_register_se_key(
const psa_key_attributes_t *attributes )
{
psa_status_t status;
psa_key_slot_t *slot = NULL;
psa_se_drv_table_entry_t *driver = NULL;
psa_key_handle_t handle = 0;
/* Leaving attributes unspecified is not currently supported.
* It could make sense to query the key type and size from the
* secure element, but not all secure elements support this
* and the driver HAL doesn't currently support it. */
if( psa_get_key_type( attributes ) == PSA_KEY_TYPE_NONE )
return( PSA_ERROR_NOT_SUPPORTED );
if( psa_get_key_bits( attributes ) == 0 )
return( PSA_ERROR_NOT_SUPPORTED );
status = psa_start_key_creation( PSA_KEY_CREATION_REGISTER, attributes,
&handle, &slot, &driver );
if( status != PSA_SUCCESS )
goto exit;
status = psa_finish_key_creation( slot, driver );
exit:
if( status != PSA_SUCCESS )
{
psa_fail_key_creation( slot, driver );
}
/* Registration doesn't keep the key in RAM. */
psa_close_key( handle );
return( status );
}
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
static psa_status_t psa_copy_key_material( const psa_key_slot_t *source,
psa_key_slot_t *target )
{
psa_status_t status;
uint8_t *buffer = NULL;
size_t buffer_size = 0;
size_t length;
buffer_size = PSA_KEY_EXPORT_MAX_SIZE( source->attr.type,
psa_get_key_slot_bits( source ) );
buffer = mbedtls_calloc( 1, buffer_size );
if( buffer == NULL )
return( PSA_ERROR_INSUFFICIENT_MEMORY );
status = psa_internal_export_key( source, buffer, buffer_size, &length, 0 );
if( status != PSA_SUCCESS )
goto exit;
target->attr.type = source->attr.type;
status = psa_import_key_into_slot( target, buffer, length );
exit:
mbedtls_platform_zeroize( buffer, buffer_size );
mbedtls_free( buffer );
return( status );
}
psa_status_t psa_copy_key( psa_key_handle_t source_handle,
const psa_key_attributes_t *specified_attributes,
psa_key_handle_t *target_handle )
{
psa_status_t status;
psa_key_slot_t *source_slot = NULL;
psa_key_slot_t *target_slot = NULL;
psa_key_attributes_t actual_attributes = *specified_attributes;
psa_se_drv_table_entry_t *driver = NULL;
status = psa_get_transparent_key( source_handle, &source_slot,
PSA_KEY_USAGE_COPY, 0 );
if( status != PSA_SUCCESS )
goto exit;
status = psa_validate_optional_attributes( source_slot,
specified_attributes );
if( status != PSA_SUCCESS )
goto exit;
status = psa_restrict_key_policy( &actual_attributes.core.policy,
&source_slot->attr.policy );
if( status != PSA_SUCCESS )
goto exit;
status = psa_start_key_creation( PSA_KEY_CREATION_COPY,
&actual_attributes,
target_handle, &target_slot, &driver );
if( status != PSA_SUCCESS )
goto exit;
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
if( driver != NULL )
{
/* Copying to a secure element is not implemented yet. */
status = PSA_ERROR_NOT_SUPPORTED;
goto exit;
}
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
status = psa_copy_key_material( source_slot, target_slot );
if( status != PSA_SUCCESS )
goto exit;
status = psa_finish_key_creation( target_slot, driver );
exit:
if( status != PSA_SUCCESS )
{
psa_fail_key_creation( target_slot, driver );
*target_handle = 0;
}
return( status );
}
/****************************************************************/
/* Message digests */
/****************************************************************/
#if defined(MBEDTLS_RSA_C) || defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA)
static const mbedtls_md_info_t *mbedtls_md_info_from_psa( psa_algorithm_t alg )
{
switch( alg )
{
#if defined(MBEDTLS_MD2_C)
case PSA_ALG_MD2:
return( &mbedtls_md2_info );
#endif
#if defined(MBEDTLS_MD4_C)
case PSA_ALG_MD4:
return( &mbedtls_md4_info );
#endif
#if defined(MBEDTLS_MD5_C)
case PSA_ALG_MD5:
return( &mbedtls_md5_info );
#endif
#if defined(MBEDTLS_RIPEMD160_C)
case PSA_ALG_RIPEMD160:
return( &mbedtls_ripemd160_info );
#endif
#if defined(MBEDTLS_SHA1_C)
case PSA_ALG_SHA_1:
return( &mbedtls_sha1_info );
#endif
#if defined(MBEDTLS_SHA256_C)
case PSA_ALG_SHA_224:
return( &mbedtls_sha224_info );
case PSA_ALG_SHA_256:
return( &mbedtls_sha256_info );
#endif
#if defined(MBEDTLS_SHA512_C)
#if !defined(MBEDTLS_SHA512_NO_SHA384)
case PSA_ALG_SHA_384:
return( &mbedtls_sha384_info );
#endif
case PSA_ALG_SHA_512:
return( &mbedtls_sha512_info );
#endif
default:
return( NULL );
}
}
#endif /* defined(MBEDTLS_RSA_C) || defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) */
psa_status_t psa_hash_abort( psa_hash_operation_t *operation )
{
switch( operation->alg )
{
case 0:
/* The object has (apparently) been initialized but it is not
* in use. It's ok to call abort on such an object, and there's
* nothing to do. */
break;
#if defined(MBEDTLS_MD2_C)
case PSA_ALG_MD2:
mbedtls_md2_free( &operation->ctx.md2 );
break;
#endif
#if defined(MBEDTLS_MD4_C)
case PSA_ALG_MD4:
mbedtls_md4_free( &operation->ctx.md4 );
break;
#endif
#if defined(MBEDTLS_MD5_C)
case PSA_ALG_MD5:
mbedtls_md5_free( &operation->ctx.md5 );
break;
#endif
#if defined(MBEDTLS_RIPEMD160_C)
case PSA_ALG_RIPEMD160:
mbedtls_ripemd160_free( &operation->ctx.ripemd160 );
break;
#endif
#if defined(MBEDTLS_SHA1_C)
case PSA_ALG_SHA_1:
mbedtls_sha1_free( &operation->ctx.sha1 );
break;
#endif
#if defined(MBEDTLS_SHA256_C)
case PSA_ALG_SHA_224:
case PSA_ALG_SHA_256:
mbedtls_sha256_free( &operation->ctx.sha256 );
break;
#endif
#if defined(MBEDTLS_SHA512_C)
#if !defined(MBEDTLS_SHA512_NO_SHA384)
case PSA_ALG_SHA_384:
#endif
case PSA_ALG_SHA_512:
mbedtls_sha512_free( &operation->ctx.sha512 );
break;
#endif
default:
return( PSA_ERROR_BAD_STATE );
}
operation->alg = 0;
return( PSA_SUCCESS );
}
psa_status_t psa_hash_setup( psa_hash_operation_t *operation,
psa_algorithm_t alg )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
/* A context must be freshly initialized before it can be set up. */
if( operation->alg != 0 )
{
return( PSA_ERROR_BAD_STATE );
}
switch( alg )
{
#if defined(MBEDTLS_MD2_C)
case PSA_ALG_MD2:
mbedtls_md2_init( &operation->ctx.md2 );
ret = mbedtls_md2_starts_ret( &operation->ctx.md2 );
break;
#endif
#if defined(MBEDTLS_MD4_C)
case PSA_ALG_MD4:
mbedtls_md4_init( &operation->ctx.md4 );
ret = mbedtls_md4_starts_ret( &operation->ctx.md4 );
break;
#endif
#if defined(MBEDTLS_MD5_C)
case PSA_ALG_MD5:
mbedtls_md5_init( &operation->ctx.md5 );
ret = mbedtls_md5_starts_ret( &operation->ctx.md5 );
break;
#endif
#if defined(MBEDTLS_RIPEMD160_C)
case PSA_ALG_RIPEMD160:
mbedtls_ripemd160_init( &operation->ctx.ripemd160 );
ret = mbedtls_ripemd160_starts_ret( &operation->ctx.ripemd160 );
break;
#endif
#if defined(MBEDTLS_SHA1_C)
case PSA_ALG_SHA_1:
mbedtls_sha1_init( &operation->ctx.sha1 );
ret = mbedtls_sha1_starts_ret( &operation->ctx.sha1 );
break;
#endif
#if defined(MBEDTLS_SHA256_C)
case PSA_ALG_SHA_224:
mbedtls_sha256_init( &operation->ctx.sha256 );
ret = mbedtls_sha256_starts_ret( &operation->ctx.sha256, 1 );
break;
case PSA_ALG_SHA_256:
mbedtls_sha256_init( &operation->ctx.sha256 );
ret = mbedtls_sha256_starts_ret( &operation->ctx.sha256, 0 );
break;
#endif
#if defined(MBEDTLS_SHA512_C)
#if !defined(MBEDTLS_SHA512_NO_SHA384)
case PSA_ALG_SHA_384:
mbedtls_sha512_init( &operation->ctx.sha512 );
ret = mbedtls_sha512_starts_ret( &operation->ctx.sha512, 1 );
break;
#endif
case PSA_ALG_SHA_512:
mbedtls_sha512_init( &operation->ctx.sha512 );
ret = mbedtls_sha512_starts_ret( &operation->ctx.sha512, 0 );
break;
#endif
default:
return( PSA_ALG_IS_HASH( alg ) ?
PSA_ERROR_NOT_SUPPORTED :
PSA_ERROR_INVALID_ARGUMENT );
}
if( ret == 0 )
operation->alg = alg;
else
psa_hash_abort( operation );
return( mbedtls_to_psa_error( ret ) );
}
psa_status_t psa_hash_update( psa_hash_operation_t *operation,
const uint8_t *input,
size_t input_length )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
/* Don't require hash implementations to behave correctly on a
* zero-length input, which may have an invalid pointer. */
if( input_length == 0 )
return( PSA_SUCCESS );
switch( operation->alg )
{
#if defined(MBEDTLS_MD2_C)
case PSA_ALG_MD2:
ret = mbedtls_md2_update_ret( &operation->ctx.md2,
input, input_length );
break;
#endif
#if defined(MBEDTLS_MD4_C)
case PSA_ALG_MD4:
ret = mbedtls_md4_update_ret( &operation->ctx.md4,
input, input_length );
break;
#endif
#if defined(MBEDTLS_MD5_C)
case PSA_ALG_MD5:
ret = mbedtls_md5_update_ret( &operation->ctx.md5,
input, input_length );
break;
#endif
#if defined(MBEDTLS_RIPEMD160_C)
case PSA_ALG_RIPEMD160:
ret = mbedtls_ripemd160_update_ret( &operation->ctx.ripemd160,
input, input_length );
break;
#endif
#if defined(MBEDTLS_SHA1_C)
case PSA_ALG_SHA_1:
ret = mbedtls_sha1_update_ret( &operation->ctx.sha1,
input, input_length );
break;
#endif
#if defined(MBEDTLS_SHA256_C)
case PSA_ALG_SHA_224:
case PSA_ALG_SHA_256:
ret = mbedtls_sha256_update_ret( &operation->ctx.sha256,
input, input_length );
break;
#endif
#if defined(MBEDTLS_SHA512_C)
#if !defined(MBEDTLS_SHA512_NO_SHA384)
case PSA_ALG_SHA_384:
#endif
case PSA_ALG_SHA_512:
ret = mbedtls_sha512_update_ret( &operation->ctx.sha512,
input, input_length );
break;
#endif
default:
return( PSA_ERROR_BAD_STATE );
}
if( ret != 0 )
psa_hash_abort( operation );
return( mbedtls_to_psa_error( ret ) );
}
psa_status_t psa_hash_finish( psa_hash_operation_t *operation,
uint8_t *hash,
size_t hash_size,
size_t *hash_length )
{
psa_status_t status;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t actual_hash_length = PSA_HASH_SIZE( operation->alg );
/* Fill the output buffer with something that isn't a valid hash
* (barring an attack on the hash and deliberately-crafted input),
* in case the caller doesn't check the return status properly. */
*hash_length = hash_size;
/* If hash_size is 0 then hash may be NULL and then the
* call to memset would have undefined behavior. */
if( hash_size != 0 )
memset( hash, '!', hash_size );
if( hash_size < actual_hash_length )
{
status = PSA_ERROR_BUFFER_TOO_SMALL;
goto exit;
}
switch( operation->alg )
{
#if defined(MBEDTLS_MD2_C)
case PSA_ALG_MD2:
ret = mbedtls_md2_finish_ret( &operation->ctx.md2, hash );
break;
#endif
#if defined(MBEDTLS_MD4_C)
case PSA_ALG_MD4:
ret = mbedtls_md4_finish_ret( &operation->ctx.md4, hash );
break;
#endif
#if defined(MBEDTLS_MD5_C)
case PSA_ALG_MD5:
ret = mbedtls_md5_finish_ret( &operation->ctx.md5, hash );
break;
#endif
#if defined(MBEDTLS_RIPEMD160_C)
case PSA_ALG_RIPEMD160:
ret = mbedtls_ripemd160_finish_ret( &operation->ctx.ripemd160, hash );
break;
#endif
#if defined(MBEDTLS_SHA1_C)
case PSA_ALG_SHA_1:
ret = mbedtls_sha1_finish_ret( &operation->ctx.sha1, hash );
break;
#endif
#if defined(MBEDTLS_SHA256_C)
case PSA_ALG_SHA_224:
case PSA_ALG_SHA_256:
ret = mbedtls_sha256_finish_ret( &operation->ctx.sha256, hash );
break;
#endif
#if defined(MBEDTLS_SHA512_C)
#if !defined(MBEDTLS_SHA512_NO_SHA384)
case PSA_ALG_SHA_384:
#endif
case PSA_ALG_SHA_512:
ret = mbedtls_sha512_finish_ret( &operation->ctx.sha512, hash );
break;
#endif
default:
return( PSA_ERROR_BAD_STATE );
}
status = mbedtls_to_psa_error( ret );
exit:
if( status == PSA_SUCCESS )
{
*hash_length = actual_hash_length;
return( psa_hash_abort( operation ) );
}
else
{
psa_hash_abort( operation );
return( status );
}
}
psa_status_t psa_hash_verify( psa_hash_operation_t *operation,
const uint8_t *hash,
size_t hash_length )
{
uint8_t actual_hash[MBEDTLS_MD_MAX_SIZE];
size_t actual_hash_length;
psa_status_t status = psa_hash_finish( operation,
actual_hash, sizeof( actual_hash ),
&actual_hash_length );
if( status != PSA_SUCCESS )
return( status );
if( actual_hash_length != hash_length )
return( PSA_ERROR_INVALID_SIGNATURE );
if( safer_memcmp( hash, actual_hash, actual_hash_length ) != 0 )
return( PSA_ERROR_INVALID_SIGNATURE );
return( PSA_SUCCESS );
}
psa_status_t psa_hash_compute( psa_algorithm_t alg,
const uint8_t *input, size_t input_length,
uint8_t *hash, size_t hash_size,
size_t *hash_length )
{
psa_hash_operation_t operation = PSA_HASH_OPERATION_INIT;
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
*hash_length = hash_size;
status = psa_hash_setup( &operation, alg );
if( status != PSA_SUCCESS )
goto exit;
status = psa_hash_update( &operation, input, input_length );
if( status != PSA_SUCCESS )
goto exit;
status = psa_hash_finish( &operation, hash, hash_size, hash_length );
if( status != PSA_SUCCESS )
goto exit;
exit:
if( status == PSA_SUCCESS )
status = psa_hash_abort( &operation );
else
psa_hash_abort( &operation );
return( status );
}
psa_status_t psa_hash_compare( psa_algorithm_t alg,
const uint8_t *input, size_t input_length,
const uint8_t *hash, size_t hash_length )
{
psa_hash_operation_t operation = PSA_HASH_OPERATION_INIT;
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
status = psa_hash_setup( &operation, alg );
if( status != PSA_SUCCESS )
goto exit;
status = psa_hash_update( &operation, input, input_length );
if( status != PSA_SUCCESS )
goto exit;
status = psa_hash_verify( &operation, hash, hash_length );
if( status != PSA_SUCCESS )
goto exit;
exit:
if( status == PSA_SUCCESS )
status = psa_hash_abort( &operation );
else
psa_hash_abort( &operation );
return( status );
}
psa_status_t psa_hash_clone( const psa_hash_operation_t *source_operation,
psa_hash_operation_t *target_operation )
{
if( target_operation->alg != 0 )
return( PSA_ERROR_BAD_STATE );
switch( source_operation->alg )
{
case 0:
return( PSA_ERROR_BAD_STATE );
#if defined(MBEDTLS_MD2_C)
case PSA_ALG_MD2:
mbedtls_md2_clone( &target_operation->ctx.md2,
&source_operation->ctx.md2 );
break;
#endif
#if defined(MBEDTLS_MD4_C)
case PSA_ALG_MD4:
mbedtls_md4_clone( &target_operation->ctx.md4,
&source_operation->ctx.md4 );
break;
#endif
#if defined(MBEDTLS_MD5_C)
case PSA_ALG_MD5:
mbedtls_md5_clone( &target_operation->ctx.md5,
&source_operation->ctx.md5 );
break;
#endif
#if defined(MBEDTLS_RIPEMD160_C)
case PSA_ALG_RIPEMD160:
mbedtls_ripemd160_clone( &target_operation->ctx.ripemd160,
&source_operation->ctx.ripemd160 );
break;
#endif
#if defined(MBEDTLS_SHA1_C)
case PSA_ALG_SHA_1:
mbedtls_sha1_clone( &target_operation->ctx.sha1,
&source_operation->ctx.sha1 );
break;
#endif
#if defined(MBEDTLS_SHA256_C)
case PSA_ALG_SHA_224:
case PSA_ALG_SHA_256:
mbedtls_sha256_clone( &target_operation->ctx.sha256,
&source_operation->ctx.sha256 );
break;
#endif
#if defined(MBEDTLS_SHA512_C)
#if !defined(MBEDTLS_SHA512_NO_SHA384)
case PSA_ALG_SHA_384:
#endif
case PSA_ALG_SHA_512:
mbedtls_sha512_clone( &target_operation->ctx.sha512,
&source_operation->ctx.sha512 );
break;
#endif
default:
return( PSA_ERROR_NOT_SUPPORTED );
}
target_operation->alg = source_operation->alg;
return( PSA_SUCCESS );
}
/****************************************************************/
/* MAC */
/****************************************************************/
static const mbedtls_cipher_info_t *mbedtls_cipher_info_from_psa(
psa_algorithm_t alg,
psa_key_type_t key_type,
size_t key_bits,
mbedtls_cipher_id_t* cipher_id )
{
mbedtls_cipher_mode_t mode;
mbedtls_cipher_id_t cipher_id_tmp;
if( PSA_ALG_IS_AEAD( alg ) )
alg = PSA_ALG_AEAD_WITH_TAG_LENGTH( alg, 0 );
if( PSA_ALG_IS_CIPHER( alg ) || PSA_ALG_IS_AEAD( alg ) )
{
switch( alg )
{
case PSA_ALG_ARC4:
case PSA_ALG_CHACHA20:
mode = MBEDTLS_MODE_STREAM;
break;
case PSA_ALG_CTR:
mode = MBEDTLS_MODE_CTR;
break;
case PSA_ALG_CFB:
mode = MBEDTLS_MODE_CFB;
break;
case PSA_ALG_OFB:
mode = MBEDTLS_MODE_OFB;
break;
case PSA_ALG_ECB_NO_PADDING:
mode = MBEDTLS_MODE_ECB;
break;
case PSA_ALG_CBC_NO_PADDING:
mode = MBEDTLS_MODE_CBC;
break;
case PSA_ALG_CBC_PKCS7:
mode = MBEDTLS_MODE_CBC;
break;
case PSA_ALG_AEAD_WITH_TAG_LENGTH( PSA_ALG_CCM, 0 ):
mode = MBEDTLS_MODE_CCM;
break;
case PSA_ALG_AEAD_WITH_TAG_LENGTH( PSA_ALG_GCM, 0 ):
mode = MBEDTLS_MODE_GCM;
break;
case PSA_ALG_AEAD_WITH_TAG_LENGTH( PSA_ALG_CHACHA20_POLY1305, 0 ):
mode = MBEDTLS_MODE_CHACHAPOLY;
break;
default:
return( NULL );
}
}
else if( alg == PSA_ALG_CMAC )
mode = MBEDTLS_MODE_ECB;
else
return( NULL );
switch( key_type )
{
case PSA_KEY_TYPE_AES:
cipher_id_tmp = MBEDTLS_CIPHER_ID_AES;
break;
case PSA_KEY_TYPE_DES:
/* key_bits is 64 for Single-DES, 128 for two-key Triple-DES,
* and 192 for three-key Triple-DES. */
if( key_bits == 64 )
cipher_id_tmp = MBEDTLS_CIPHER_ID_DES;
else
cipher_id_tmp = MBEDTLS_CIPHER_ID_3DES;
/* mbedtls doesn't recognize two-key Triple-DES as an algorithm,
* but two-key Triple-DES is functionally three-key Triple-DES
* with K1=K3, so that's how we present it to mbedtls. */
if( key_bits == 128 )
key_bits = 192;
break;
case PSA_KEY_TYPE_CAMELLIA:
cipher_id_tmp = MBEDTLS_CIPHER_ID_CAMELLIA;
break;
case PSA_KEY_TYPE_ARC4:
cipher_id_tmp = MBEDTLS_CIPHER_ID_ARC4;
break;
case PSA_KEY_TYPE_CHACHA20:
cipher_id_tmp = MBEDTLS_CIPHER_ID_CHACHA20;
break;
default:
return( NULL );
}
if( cipher_id != NULL )
*cipher_id = cipher_id_tmp;
return( mbedtls_cipher_info_from_values( cipher_id_tmp,
(int) key_bits, mode ) );
}
#if defined(MBEDTLS_MD_C)
static size_t psa_get_hash_block_size( psa_algorithm_t alg )
{
switch( alg )
{
case PSA_ALG_MD2:
return( 16 );
case PSA_ALG_MD4:
return( 64 );
case PSA_ALG_MD5:
return( 64 );
case PSA_ALG_RIPEMD160:
return( 64 );
case PSA_ALG_SHA_1:
return( 64 );
case PSA_ALG_SHA_224:
return( 64 );
case PSA_ALG_SHA_256:
return( 64 );
case PSA_ALG_SHA_384:
return( 128 );
case PSA_ALG_SHA_512:
return( 128 );
default:
return( 0 );
}
}
#endif /* MBEDTLS_MD_C */
/* Initialize the MAC operation structure. Once this function has been
* called, psa_mac_abort can run and will do the right thing. */
static psa_status_t psa_mac_init( psa_mac_operation_t *operation,
psa_algorithm_t alg )
{
psa_status_t status = PSA_ERROR_NOT_SUPPORTED;
operation->alg = alg;
operation->key_set = 0;
operation->iv_set = 0;
operation->iv_required = 0;
operation->has_input = 0;
operation->is_sign = 0;
#if defined(MBEDTLS_CMAC_C)
if( alg == PSA_ALG_CMAC )
{
operation->iv_required = 0;
mbedtls_cipher_init( &operation->ctx.cmac );
status = PSA_SUCCESS;
}
else
#endif /* MBEDTLS_CMAC_C */
#if defined(MBEDTLS_MD_C)
if( PSA_ALG_IS_HMAC( operation->alg ) )
{
/* We'll set up the hash operation later in psa_hmac_setup_internal. */
operation->ctx.hmac.hash_ctx.alg = 0;
status = PSA_SUCCESS;
}
else
#endif /* MBEDTLS_MD_C */
{
if( ! PSA_ALG_IS_MAC( alg ) )
status = PSA_ERROR_INVALID_ARGUMENT;
}
if( status != PSA_SUCCESS )
memset( operation, 0, sizeof( *operation ) );
return( status );
}
#if defined(MBEDTLS_MD_C)
static psa_status_t psa_hmac_abort_internal( psa_hmac_internal_data *hmac )
{
mbedtls_platform_zeroize( hmac->opad, sizeof( hmac->opad ) );
return( psa_hash_abort( &hmac->hash_ctx ) );
}
#endif /* MBEDTLS_MD_C */
psa_status_t psa_mac_abort( psa_mac_operation_t *operation )
{
if( operation->alg == 0 )
{
/* The object has (apparently) been initialized but it is not
* in use. It's ok to call abort on such an object, and there's
* nothing to do. */
return( PSA_SUCCESS );
}
else
#if defined(MBEDTLS_CMAC_C)
if( operation->alg == PSA_ALG_CMAC )
{
mbedtls_cipher_free( &operation->ctx.cmac );
}
else
#endif /* MBEDTLS_CMAC_C */
#if defined(MBEDTLS_MD_C)
if( PSA_ALG_IS_HMAC( operation->alg ) )
{
psa_hmac_abort_internal( &operation->ctx.hmac );
}
else
#endif /* MBEDTLS_MD_C */
{
/* Sanity check (shouldn't happen: operation->alg should
* always have been initialized to a valid value). */
goto bad_state;
}
operation->alg = 0;
operation->key_set = 0;
operation->iv_set = 0;
operation->iv_required = 0;
operation->has_input = 0;
operation->is_sign = 0;
return( PSA_SUCCESS );
bad_state:
/* If abort is called on an uninitialized object, we can't trust
* anything. Wipe the object in case it contains confidential data.
* This may result in a memory leak if a pointer gets overwritten,
* but it's too late to do anything about this. */
memset( operation, 0, sizeof( *operation ) );
return( PSA_ERROR_BAD_STATE );
}
#if defined(MBEDTLS_CMAC_C)
static int psa_cmac_setup( psa_mac_operation_t *operation,
size_t key_bits,
psa_key_slot_t *slot,
const mbedtls_cipher_info_t *cipher_info )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
operation->mac_size = cipher_info->block_size;
ret = mbedtls_cipher_setup( &operation->ctx.cmac, cipher_info );
if( ret != 0 )
return( ret );
ret = mbedtls_cipher_cmac_starts( &operation->ctx.cmac,
slot->data.key.data,
key_bits );
return( ret );
}
#endif /* MBEDTLS_CMAC_C */
#if defined(MBEDTLS_MD_C)
static psa_status_t psa_hmac_setup_internal( psa_hmac_internal_data *hmac,
const uint8_t *key,
size_t key_length,
psa_algorithm_t hash_alg )
{
uint8_t ipad[PSA_HMAC_MAX_HASH_BLOCK_SIZE];
size_t i;
size_t hash_size = PSA_HASH_SIZE( hash_alg );
size_t block_size = psa_get_hash_block_size( hash_alg );
psa_status_t status;
/* Sanity checks on block_size, to guarantee that there won't be a buffer
* overflow below. This should never trigger if the hash algorithm
* is implemented correctly. */
/* The size checks against the ipad and opad buffers cannot be written
* `block_size > sizeof( ipad ) || block_size > sizeof( hmac->opad )`
* because that triggers -Wlogical-op on GCC 7.3. */
if( block_size > sizeof( ipad ) )
return( PSA_ERROR_NOT_SUPPORTED );
if( block_size > sizeof( hmac->opad ) )
return( PSA_ERROR_NOT_SUPPORTED );
if( block_size < hash_size )
return( PSA_ERROR_NOT_SUPPORTED );
if( key_length > block_size )
{
status = psa_hash_compute( hash_alg, key, key_length,
ipad, sizeof( ipad ), &key_length );
if( status != PSA_SUCCESS )
goto cleanup;
}
/* A 0-length key is not commonly used in HMAC when used as a MAC,
* but it is permitted. It is common when HMAC is used in HKDF, for
* example. Don't call `memcpy` in the 0-length because `key` could be
* an invalid pointer which would make the behavior undefined. */
else if( key_length != 0 )
memcpy( ipad, key, key_length );
/* ipad contains the key followed by garbage. Xor and fill with 0x36
* to create the ipad value. */
for( i = 0; i < key_length; i++ )
ipad[i] ^= 0x36;
memset( ipad + key_length, 0x36, block_size - key_length );
/* Copy the key material from ipad to opad, flipping the requisite bits,
* and filling the rest of opad with the requisite constant. */
for( i = 0; i < key_length; i++ )
hmac->opad[i] = ipad[i] ^ 0x36 ^ 0x5C;
memset( hmac->opad + key_length, 0x5C, block_size - key_length );
status = psa_hash_setup( &hmac->hash_ctx, hash_alg );
if( status != PSA_SUCCESS )
goto cleanup;
status = psa_hash_update( &hmac->hash_ctx, ipad, block_size );
cleanup:
mbedtls_platform_zeroize( ipad, sizeof( ipad ) );
return( status );
}
#endif /* MBEDTLS_MD_C */
static psa_status_t psa_mac_setup( psa_mac_operation_t *operation,
psa_key_handle_t handle,
psa_algorithm_t alg,
int is_sign )
{
psa_status_t status;
psa_key_slot_t *slot;
size_t key_bits;
psa_key_usage_t usage =
is_sign ? PSA_KEY_USAGE_SIGN_HASH : PSA_KEY_USAGE_VERIFY_HASH;
uint8_t truncated = PSA_MAC_TRUNCATED_LENGTH( alg );
psa_algorithm_t full_length_alg = PSA_ALG_FULL_LENGTH_MAC( alg );
/* A context must be freshly initialized before it can be set up. */
if( operation->alg != 0 )
{
return( PSA_ERROR_BAD_STATE );
}
status = psa_mac_init( operation, full_length_alg );
if( status != PSA_SUCCESS )
return( status );
if( is_sign )
operation->is_sign = 1;
status = psa_get_transparent_key( handle, &slot, usage, alg );
if( status != PSA_SUCCESS )
goto exit;
key_bits = psa_get_key_slot_bits( slot );
#if defined(MBEDTLS_CMAC_C)
if( full_length_alg == PSA_ALG_CMAC )
{
const mbedtls_cipher_info_t *cipher_info =
mbedtls_cipher_info_from_psa( full_length_alg,
slot->attr.type, key_bits, NULL );
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
if( cipher_info == NULL )
{
status = PSA_ERROR_NOT_SUPPORTED;
goto exit;
}
operation->mac_size = cipher_info->block_size;
ret = psa_cmac_setup( operation, key_bits, slot, cipher_info );
status = mbedtls_to_psa_error( ret );
}
else
#endif /* MBEDTLS_CMAC_C */
#if defined(MBEDTLS_MD_C)
if( PSA_ALG_IS_HMAC( full_length_alg ) )
{
psa_algorithm_t hash_alg = PSA_ALG_HMAC_GET_HASH( alg );
if( hash_alg == 0 )
{
status = PSA_ERROR_NOT_SUPPORTED;
goto exit;
}
operation->mac_size = PSA_HASH_SIZE( hash_alg );
/* Sanity check. This shouldn't fail on a valid configuration. */
if( operation->mac_size == 0 ||
operation->mac_size > sizeof( operation->ctx.hmac.opad ) )
{
status = PSA_ERROR_NOT_SUPPORTED;
goto exit;
}
if( slot->attr.type != PSA_KEY_TYPE_HMAC )
{
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
status = psa_hmac_setup_internal( &operation->ctx.hmac,
slot->data.key.data,
slot->data.key.bytes,
hash_alg );
}
else
#endif /* MBEDTLS_MD_C */
{
(void) key_bits;
status = PSA_ERROR_NOT_SUPPORTED;
}
if( truncated == 0 )
{
/* The "normal" case: untruncated algorithm. Nothing to do. */
}
else if( truncated < 4 )
{
/* A very short MAC is too short for security since it can be
* brute-forced. Ancient protocols with 32-bit MACs do exist,
* so we make this our minimum, even though 32 bits is still
* too small for security. */
status = PSA_ERROR_NOT_SUPPORTED;
}
else if( truncated > operation->mac_size )
{
/* It's impossible to "truncate" to a larger length. */
status = PSA_ERROR_INVALID_ARGUMENT;
}
else
operation->mac_size = truncated;
exit:
if( status != PSA_SUCCESS )
{
psa_mac_abort( operation );
}
else
{
operation->key_set = 1;
}
return( status );
}
psa_status_t psa_mac_sign_setup( psa_mac_operation_t *operation,
psa_key_handle_t handle,
psa_algorithm_t alg )
{
return( psa_mac_setup( operation, handle, alg, 1 ) );
}
psa_status_t psa_mac_verify_setup( psa_mac_operation_t *operation,
psa_key_handle_t handle,
psa_algorithm_t alg )
{
return( psa_mac_setup( operation, handle, alg, 0 ) );
}
psa_status_t psa_mac_update( psa_mac_operation_t *operation,
const uint8_t *input,
size_t input_length )
{
psa_status_t status = PSA_ERROR_BAD_STATE;
if( ! operation->key_set )
return( PSA_ERROR_BAD_STATE );
if( operation->iv_required && ! operation->iv_set )
return( PSA_ERROR_BAD_STATE );
operation->has_input = 1;
#if defined(MBEDTLS_CMAC_C)
if( operation->alg == PSA_ALG_CMAC )
{
int ret = mbedtls_cipher_cmac_update( &operation->ctx.cmac,
input, input_length );
status = mbedtls_to_psa_error( ret );
}
else
#endif /* MBEDTLS_CMAC_C */
#if defined(MBEDTLS_MD_C)
if( PSA_ALG_IS_HMAC( operation->alg ) )
{
status = psa_hash_update( &operation->ctx.hmac.hash_ctx, input,
input_length );
}
else
#endif /* MBEDTLS_MD_C */
{
/* This shouldn't happen if `operation` was initialized by
* a setup function. */
return( PSA_ERROR_BAD_STATE );
}
if( status != PSA_SUCCESS )
psa_mac_abort( operation );
return( status );
}
#if defined(MBEDTLS_MD_C)
static psa_status_t psa_hmac_finish_internal( psa_hmac_internal_data *hmac,
uint8_t *mac,
size_t mac_size )
{
uint8_t tmp[MBEDTLS_MD_MAX_SIZE];
psa_algorithm_t hash_alg = hmac->hash_ctx.alg;
size_t hash_size = 0;
size_t block_size = psa_get_hash_block_size( hash_alg );
psa_status_t status;
status = psa_hash_finish( &hmac->hash_ctx, tmp, sizeof( tmp ), &hash_size );
if( status != PSA_SUCCESS )
return( status );
/* From here on, tmp needs to be wiped. */
status = psa_hash_setup( &hmac->hash_ctx, hash_alg );
if( status != PSA_SUCCESS )
goto exit;
status = psa_hash_update( &hmac->hash_ctx, hmac->opad, block_size );
if( status != PSA_SUCCESS )
goto exit;
status = psa_hash_update( &hmac->hash_ctx, tmp, hash_size );
if( status != PSA_SUCCESS )
goto exit;
status = psa_hash_finish( &hmac->hash_ctx, tmp, sizeof( tmp ), &hash_size );
if( status != PSA_SUCCESS )
goto exit;
memcpy( mac, tmp, mac_size );
exit:
mbedtls_platform_zeroize( tmp, hash_size );
return( status );
}
#endif /* MBEDTLS_MD_C */
static psa_status_t psa_mac_finish_internal( psa_mac_operation_t *operation,
uint8_t *mac,
size_t mac_size )
{
if( ! operation->key_set )
return( PSA_ERROR_BAD_STATE );
if( operation->iv_required && ! operation->iv_set )
return( PSA_ERROR_BAD_STATE );
if( mac_size < operation->mac_size )
return( PSA_ERROR_BUFFER_TOO_SMALL );
#if defined(MBEDTLS_CMAC_C)
if( operation->alg == PSA_ALG_CMAC )
{
uint8_t tmp[PSA_MAX_BLOCK_CIPHER_BLOCK_SIZE];
int ret = mbedtls_cipher_cmac_finish( &operation->ctx.cmac, tmp );
if( ret == 0 )
memcpy( mac, tmp, operation->mac_size );
mbedtls_platform_zeroize( tmp, sizeof( tmp ) );
return( mbedtls_to_psa_error( ret ) );
}
else
#endif /* MBEDTLS_CMAC_C */
#if defined(MBEDTLS_MD_C)
if( PSA_ALG_IS_HMAC( operation->alg ) )
{
return( psa_hmac_finish_internal( &operation->ctx.hmac,
mac, operation->mac_size ) );
}
else
#endif /* MBEDTLS_MD_C */
{
/* This shouldn't happen if `operation` was initialized by
* a setup function. */
return( PSA_ERROR_BAD_STATE );
}
}
psa_status_t psa_mac_sign_finish( psa_mac_operation_t *operation,
uint8_t *mac,
size_t mac_size,
size_t *mac_length )
{
psa_status_t status;
if( operation->alg == 0 )
{
return( PSA_ERROR_BAD_STATE );
}
/* Fill the output buffer with something that isn't a valid mac
* (barring an attack on the mac and deliberately-crafted input),
* in case the caller doesn't check the return status properly. */
*mac_length = mac_size;
/* If mac_size is 0 then mac may be NULL and then the
* call to memset would have undefined behavior. */
if( mac_size != 0 )
memset( mac, '!', mac_size );
if( ! operation->is_sign )
{
return( PSA_ERROR_BAD_STATE );
}
status = psa_mac_finish_internal( operation, mac, mac_size );
if( status == PSA_SUCCESS )
{
status = psa_mac_abort( operation );
if( status == PSA_SUCCESS )
*mac_length = operation->mac_size;
else
memset( mac, '!', mac_size );
}
else
psa_mac_abort( operation );
return( status );
}
psa_status_t psa_mac_verify_finish( psa_mac_operation_t *operation,
const uint8_t *mac,
size_t mac_length )
{
uint8_t actual_mac[PSA_MAC_MAX_SIZE];
psa_status_t status;
if( operation->alg == 0 )
{
return( PSA_ERROR_BAD_STATE );
}
if( operation->is_sign )
{
return( PSA_ERROR_BAD_STATE );
}
if( operation->mac_size != mac_length )
{
status = PSA_ERROR_INVALID_SIGNATURE;
goto cleanup;
}
status = psa_mac_finish_internal( operation,
actual_mac, sizeof( actual_mac ) );
if( status != PSA_SUCCESS )
goto cleanup;
if( safer_memcmp( mac, actual_mac, mac_length ) != 0 )
status = PSA_ERROR_INVALID_SIGNATURE;
cleanup:
if( status == PSA_SUCCESS )
status = psa_mac_abort( operation );
else
psa_mac_abort( operation );
mbedtls_platform_zeroize( actual_mac, sizeof( actual_mac ) );
return( status );
}
/****************************************************************/
/* Asymmetric cryptography */
/****************************************************************/
#if defined(MBEDTLS_RSA_C)
/* Decode the hash algorithm from alg and store the mbedtls encoding in
* md_alg. Verify that the hash length is acceptable. */
static psa_status_t psa_rsa_decode_md_type( psa_algorithm_t alg,
size_t hash_length,
mbedtls_md_type_t *md_alg )
{
psa_algorithm_t hash_alg = PSA_ALG_SIGN_GET_HASH( alg );
const mbedtls_md_info_t *md_info = mbedtls_md_info_from_psa( hash_alg );
*md_alg = mbedtls_md_get_type( md_info );
/* The Mbed TLS RSA module uses an unsigned int for hash length
* parameters. Validate that it fits so that we don't risk an
* overflow later. */
#if SIZE_MAX > UINT_MAX
if( hash_length > UINT_MAX )
return( PSA_ERROR_INVALID_ARGUMENT );
#endif
#if defined(MBEDTLS_PKCS1_V15)
/* For PKCS#1 v1.5 signature, if using a hash, the hash length
* must be correct. */
if( PSA_ALG_IS_RSA_PKCS1V15_SIGN( alg ) &&
alg != PSA_ALG_RSA_PKCS1V15_SIGN_RAW )
{
if( md_info == NULL )
return( PSA_ERROR_NOT_SUPPORTED );
if( mbedtls_md_get_size( md_info ) != hash_length )
return( PSA_ERROR_INVALID_ARGUMENT );
}
#endif /* MBEDTLS_PKCS1_V15 */
#if defined(MBEDTLS_PKCS1_V21)
/* PSS requires a hash internally. */
if( PSA_ALG_IS_RSA_PSS( alg ) )
{
if( md_info == NULL )
return( PSA_ERROR_NOT_SUPPORTED );
}
#endif /* MBEDTLS_PKCS1_V21 */
return( PSA_SUCCESS );
}
static psa_status_t psa_rsa_sign( mbedtls_rsa_context *rsa,
psa_algorithm_t alg,
const uint8_t *hash,
size_t hash_length,
uint8_t *signature,
size_t signature_size,
size_t *signature_length )
{
psa_status_t status;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
mbedtls_md_type_t md_alg;
status = psa_rsa_decode_md_type( alg, hash_length, &md_alg );
if( status != PSA_SUCCESS )
return( status );
if( signature_size < mbedtls_rsa_get_len( rsa ) )
return( PSA_ERROR_BUFFER_TOO_SMALL );
#if defined(MBEDTLS_PKCS1_V15)
if( PSA_ALG_IS_RSA_PKCS1V15_SIGN( alg ) )
{
mbedtls_rsa_set_padding( rsa, MBEDTLS_RSA_PKCS_V15,
MBEDTLS_MD_NONE );
ret = mbedtls_rsa_pkcs1_sign( rsa,
mbedtls_ctr_drbg_random,
&global_data.ctr_drbg,
MBEDTLS_RSA_PRIVATE,
md_alg,
(unsigned int) hash_length,
hash,
signature );
}
else
#endif /* MBEDTLS_PKCS1_V15 */
#if defined(MBEDTLS_PKCS1_V21)
if( PSA_ALG_IS_RSA_PSS( alg ) )
{
mbedtls_rsa_set_padding( rsa, MBEDTLS_RSA_PKCS_V21, md_alg );
ret = mbedtls_rsa_rsassa_pss_sign( rsa,
mbedtls_ctr_drbg_random,
&global_data.ctr_drbg,
MBEDTLS_RSA_PRIVATE,
MBEDTLS_MD_NONE,
(unsigned int) hash_length,
hash,
signature );
}
else
#endif /* MBEDTLS_PKCS1_V21 */
{
return( PSA_ERROR_INVALID_ARGUMENT );
}
if( ret == 0 )
*signature_length = mbedtls_rsa_get_len( rsa );
return( mbedtls_to_psa_error( ret ) );
}
static psa_status_t psa_rsa_verify( mbedtls_rsa_context *rsa,
psa_algorithm_t alg,
const uint8_t *hash,
size_t hash_length,
const uint8_t *signature,
size_t signature_length )
{
psa_status_t status;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
mbedtls_md_type_t md_alg;
status = psa_rsa_decode_md_type( alg, hash_length, &md_alg );
if( status != PSA_SUCCESS )
return( status );
if( signature_length != mbedtls_rsa_get_len( rsa ) )
return( PSA_ERROR_INVALID_SIGNATURE );
#if defined(MBEDTLS_PKCS1_V15)
if( PSA_ALG_IS_RSA_PKCS1V15_SIGN( alg ) )
{
mbedtls_rsa_set_padding( rsa, MBEDTLS_RSA_PKCS_V15,
MBEDTLS_MD_NONE );
ret = mbedtls_rsa_pkcs1_verify( rsa,
mbedtls_ctr_drbg_random,
&global_data.ctr_drbg,
MBEDTLS_RSA_PUBLIC,
md_alg,
(unsigned int) hash_length,
hash,
signature );
}
else
#endif /* MBEDTLS_PKCS1_V15 */
#if defined(MBEDTLS_PKCS1_V21)
if( PSA_ALG_IS_RSA_PSS( alg ) )
{
mbedtls_rsa_set_padding( rsa, MBEDTLS_RSA_PKCS_V21, md_alg );
ret = mbedtls_rsa_rsassa_pss_verify( rsa,
mbedtls_ctr_drbg_random,
&global_data.ctr_drbg,
MBEDTLS_RSA_PUBLIC,
MBEDTLS_MD_NONE,
(unsigned int) hash_length,
hash,
signature );
}
else
#endif /* MBEDTLS_PKCS1_V21 */
{
return( PSA_ERROR_INVALID_ARGUMENT );
}
/* Mbed TLS distinguishes "invalid padding" from "valid padding but
* the rest of the signature is invalid". This has little use in
* practice and PSA doesn't report this distinction. */
if( ret == MBEDTLS_ERR_RSA_INVALID_PADDING )
return( PSA_ERROR_INVALID_SIGNATURE );
return( mbedtls_to_psa_error( ret ) );
}
#endif /* MBEDTLS_RSA_C */
#if defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA)
/* `ecp` cannot be const because `ecp->grp` needs to be non-const
* for mbedtls_ecdsa_sign() and mbedtls_ecdsa_sign_det()
* (even though these functions don't modify it). */
static psa_status_t psa_ecdsa_sign( mbedtls_ecp_keypair *ecp,
psa_algorithm_t alg,
const uint8_t *hash,
size_t hash_length,
uint8_t *signature,
size_t signature_size,
size_t *signature_length )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
mbedtls_mpi r, s;
size_t curve_bytes = PSA_BITS_TO_BYTES( ecp->grp.pbits );
mbedtls_mpi_init( &r );
mbedtls_mpi_init( &s );
if( signature_size < 2 * curve_bytes )
{
ret = MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL;
goto cleanup;
}
#if defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA)
if( PSA_ALG_DSA_IS_DETERMINISTIC( alg ) )
{
psa_algorithm_t hash_alg = PSA_ALG_SIGN_GET_HASH( alg );
const mbedtls_md_info_t *md_info = mbedtls_md_info_from_psa( hash_alg );
mbedtls_md_type_t md_alg = mbedtls_md_get_type( md_info );
MBEDTLS_MPI_CHK( mbedtls_ecdsa_sign_det_ext( &ecp->grp, &r, &s,
&ecp->d, hash,
hash_length, md_alg,
mbedtls_ctr_drbg_random,
&global_data.ctr_drbg ) );
}
else
#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) */
{
(void) alg;
MBEDTLS_MPI_CHK( mbedtls_ecdsa_sign( &ecp->grp, &r, &s, &ecp->d,
hash, hash_length,
mbedtls_ctr_drbg_random,
&global_data.ctr_drbg ) );
}
MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &r,
signature,
curve_bytes ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &s,
signature + curve_bytes,
curve_bytes ) );
cleanup:
mbedtls_mpi_free( &r );
mbedtls_mpi_free( &s );
if( ret == 0 )
*signature_length = 2 * curve_bytes;
return( mbedtls_to_psa_error( ret ) );
}
static psa_status_t psa_ecdsa_verify( mbedtls_ecp_keypair *ecp,
const uint8_t *hash,
size_t hash_length,
const uint8_t *signature,
size_t signature_length )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
mbedtls_mpi r, s;
size_t curve_bytes = PSA_BITS_TO_BYTES( ecp->grp.pbits );
mbedtls_mpi_init( &r );
mbedtls_mpi_init( &s );
if( signature_length != 2 * curve_bytes )
return( PSA_ERROR_INVALID_SIGNATURE );
MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( &r,
signature,
curve_bytes ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_read_binary( &s,
signature + curve_bytes,
curve_bytes ) );
/* Check whether the public part is loaded. If not, load it. */
if( mbedtls_ecp_is_zero( &ecp->Q ) )
{
MBEDTLS_MPI_CHK(
mbedtls_ecp_mul( &ecp->grp, &ecp->Q, &ecp->d, &ecp->grp.G,
mbedtls_ctr_drbg_random, &global_data.ctr_drbg ) );
}
ret = mbedtls_ecdsa_verify( &ecp->grp, hash, hash_length,
&ecp->Q, &r, &s );
cleanup:
mbedtls_mpi_free( &r );
mbedtls_mpi_free( &s );
return( mbedtls_to_psa_error( ret ) );
}
#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA */
psa_status_t psa_sign_hash( psa_key_handle_t handle,
psa_algorithm_t alg,
const uint8_t *hash,
size_t hash_length,
uint8_t *signature,
size_t signature_size,
size_t *signature_length )
{
psa_key_slot_t *slot;
psa_status_t status;
*signature_length = signature_size;
/* Immediately reject a zero-length signature buffer. This guarantees
* that signature must be a valid pointer. (On the other hand, the hash
* buffer can in principle be empty since it doesn't actually have
* to be a hash.) */
if( signature_size == 0 )
return( PSA_ERROR_BUFFER_TOO_SMALL );
status = psa_get_key_from_slot( handle, &slot, PSA_KEY_USAGE_SIGN_HASH, alg );
if( status != PSA_SUCCESS )
goto exit;
if( ! PSA_KEY_TYPE_IS_KEY_PAIR( slot->attr.type ) )
{
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
/* Try any of the available accelerators first */
status = psa_driver_wrapper_sign_hash( slot,
alg,
hash,
hash_length,
signature,
signature_size,
signature_length );
if( status != PSA_ERROR_NOT_SUPPORTED ||
psa_key_lifetime_is_external( slot->attr.lifetime ) )
goto exit;
/* If the operation was not supported by any accelerator, try fallback. */
#if defined(MBEDTLS_RSA_C)
if( slot->attr.type == PSA_KEY_TYPE_RSA_KEY_PAIR )
{
mbedtls_rsa_context *rsa = NULL;
status = psa_load_rsa_representation( slot->attr.type,
slot->data.key.data,
slot->data.key.bytes,
&rsa );
if( status != PSA_SUCCESS )
goto exit;
status = psa_rsa_sign( rsa,
alg,
hash, hash_length,
signature, signature_size,
signature_length );
mbedtls_rsa_free( rsa );
mbedtls_free( rsa );
}
else
#endif /* defined(MBEDTLS_RSA_C) */
#if defined(MBEDTLS_ECP_C)
if( PSA_KEY_TYPE_IS_ECC( slot->attr.type ) )
{
#if defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA)
if(
#if defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA)
PSA_ALG_IS_ECDSA( alg )
#else
PSA_ALG_IS_RANDOMIZED_ECDSA( alg )
#endif
)
{
mbedtls_ecp_keypair *ecp = NULL;
status = psa_load_ecp_representation( slot->attr.type,
slot->data.key.data,
slot->data.key.bytes,
&ecp );
if( status != PSA_SUCCESS )
goto exit;
status = psa_ecdsa_sign( ecp,
alg,
hash, hash_length,
signature, signature_size,
signature_length );
mbedtls_ecp_keypair_free( ecp );
mbedtls_free( ecp );
}
else
#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) */
{
status = PSA_ERROR_INVALID_ARGUMENT;
}
}
else
#endif /* defined(MBEDTLS_ECP_C) */
{
status = PSA_ERROR_NOT_SUPPORTED;
}
exit:
/* Fill the unused part of the output buffer (the whole buffer on error,
* the trailing part on success) with something that isn't a valid mac
* (barring an attack on the mac and deliberately-crafted input),
* in case the caller doesn't check the return status properly. */
if( status == PSA_SUCCESS )
memset( signature + *signature_length, '!',
signature_size - *signature_length );
else
memset( signature, '!', signature_size );
/* If signature_size is 0 then we have nothing to do. We must not call
* memset because signature may be NULL in this case. */
return( status );
}
psa_status_t psa_verify_hash( psa_key_handle_t handle,
psa_algorithm_t alg,
const uint8_t *hash,
size_t hash_length,
const uint8_t *signature,
size_t signature_length )
{
psa_key_slot_t *slot;
psa_status_t status;
status = psa_get_key_from_slot( handle, &slot, PSA_KEY_USAGE_VERIFY_HASH, alg );
if( status != PSA_SUCCESS )
return( status );
/* Try any of the available accelerators first */
status = psa_driver_wrapper_verify_hash( slot,
alg,
hash,
hash_length,
signature,
signature_length );
if( status != PSA_ERROR_NOT_SUPPORTED ||
psa_key_lifetime_is_external( slot->attr.lifetime ) )
return status;
#if defined(MBEDTLS_RSA_C)
if( PSA_KEY_TYPE_IS_RSA( slot->attr.type ) )
{
mbedtls_rsa_context *rsa = NULL;
status = psa_load_rsa_representation( slot->attr.type,
slot->data.key.data,
slot->data.key.bytes,
&rsa );
if( status != PSA_SUCCESS )
return( status );
status = psa_rsa_verify( rsa,
alg,
hash, hash_length,
signature, signature_length );
mbedtls_rsa_free( rsa );
mbedtls_free( rsa );
return( status );
}
else
#endif /* defined(MBEDTLS_RSA_C) */
#if defined(MBEDTLS_ECP_C)
if( PSA_KEY_TYPE_IS_ECC( slot->attr.type ) )
{
#if defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA)
if( PSA_ALG_IS_ECDSA( alg ) )
{
mbedtls_ecp_keypair *ecp = NULL;
status = psa_load_ecp_representation( slot->attr.type,
slot->data.key.data,
slot->data.key.bytes,
&ecp );
if( status != PSA_SUCCESS )
return( status );
status = psa_ecdsa_verify( ecp,
hash, hash_length,
signature, signature_length );
mbedtls_ecp_keypair_free( ecp );
mbedtls_free( ecp );
return( status );
}
else
#endif /* defined(MBEDTLS_PSA_BUILTIN_ALG_ECDSA) || defined(MBEDTLS_PSA_BUILTIN_ALG_DETERMINISTIC_ECDSA) */
{
return( PSA_ERROR_INVALID_ARGUMENT );
}
}
else
#endif /* defined(MBEDTLS_ECP_C) */
{
return( PSA_ERROR_NOT_SUPPORTED );
}
}
#if defined(MBEDTLS_RSA_C) && defined(MBEDTLS_PKCS1_V21)
static void psa_rsa_oaep_set_padding_mode( psa_algorithm_t alg,
mbedtls_rsa_context *rsa )
{
psa_algorithm_t hash_alg = PSA_ALG_RSA_OAEP_GET_HASH( alg );
const mbedtls_md_info_t *md_info = mbedtls_md_info_from_psa( hash_alg );
mbedtls_md_type_t md_alg = mbedtls_md_get_type( md_info );
mbedtls_rsa_set_padding( rsa, MBEDTLS_RSA_PKCS_V21, md_alg );
}
#endif /* defined(MBEDTLS_RSA_C) && defined(MBEDTLS_PKCS1_V21) */
psa_status_t psa_asymmetric_encrypt( psa_key_handle_t handle,
psa_algorithm_t alg,
const uint8_t *input,
size_t input_length,
const uint8_t *salt,
size_t salt_length,
uint8_t *output,
size_t output_size,
size_t *output_length )
{
psa_key_slot_t *slot;
psa_status_t status;
(void) input;
(void) input_length;
(void) salt;
(void) output;
(void) output_size;
*output_length = 0;
if( ! PSA_ALG_IS_RSA_OAEP( alg ) && salt_length != 0 )
return( PSA_ERROR_INVALID_ARGUMENT );
status = psa_get_transparent_key( handle, &slot, PSA_KEY_USAGE_ENCRYPT, alg );
if( status != PSA_SUCCESS )
return( status );
if( ! ( PSA_KEY_TYPE_IS_PUBLIC_KEY( slot->attr.type ) ||
PSA_KEY_TYPE_IS_KEY_PAIR( slot->attr.type ) ) )
return( PSA_ERROR_INVALID_ARGUMENT );
#if defined(MBEDTLS_RSA_C)
if( PSA_KEY_TYPE_IS_RSA( slot->attr.type ) )
{
mbedtls_rsa_context *rsa = NULL;
status = psa_load_rsa_representation( slot->attr.type,
slot->data.key.data,
slot->data.key.bytes,
&rsa );
if( status != PSA_SUCCESS )
goto rsa_exit;
if( output_size < mbedtls_rsa_get_len( rsa ) )
{
status = PSA_ERROR_BUFFER_TOO_SMALL;
goto rsa_exit;
}
#if defined(MBEDTLS_PKCS1_V15)
if( alg == PSA_ALG_RSA_PKCS1V15_CRYPT )
{
status = mbedtls_to_psa_error(
mbedtls_rsa_pkcs1_encrypt( rsa,
mbedtls_ctr_drbg_random,
&global_data.ctr_drbg,
MBEDTLS_RSA_PUBLIC,
input_length,
input,
output ) );
}
else
#endif /* MBEDTLS_PKCS1_V15 */
#if defined(MBEDTLS_PKCS1_V21)
if( PSA_ALG_IS_RSA_OAEP( alg ) )
{
psa_rsa_oaep_set_padding_mode( alg, rsa );
status = mbedtls_to_psa_error(
mbedtls_rsa_rsaes_oaep_encrypt( rsa,
mbedtls_ctr_drbg_random,
&global_data.ctr_drbg,
MBEDTLS_RSA_PUBLIC,
salt, salt_length,
input_length,
input,
output ) );
}
else
#endif /* MBEDTLS_PKCS1_V21 */
{
status = PSA_ERROR_INVALID_ARGUMENT;
goto rsa_exit;
}
rsa_exit:
if( status == PSA_SUCCESS )
*output_length = mbedtls_rsa_get_len( rsa );
mbedtls_rsa_free( rsa );
mbedtls_free( rsa );
return( status );
}
else
#endif /* defined(MBEDTLS_RSA_C) */
{
return( PSA_ERROR_NOT_SUPPORTED );
}
}
psa_status_t psa_asymmetric_decrypt( psa_key_handle_t handle,
psa_algorithm_t alg,
const uint8_t *input,
size_t input_length,
const uint8_t *salt,
size_t salt_length,
uint8_t *output,
size_t output_size,
size_t *output_length )
{
psa_key_slot_t *slot;
psa_status_t status;
(void) input;
(void) input_length;
(void) salt;
(void) output;
(void) output_size;
*output_length = 0;
if( ! PSA_ALG_IS_RSA_OAEP( alg ) && salt_length != 0 )
return( PSA_ERROR_INVALID_ARGUMENT );
status = psa_get_transparent_key( handle, &slot, PSA_KEY_USAGE_DECRYPT, alg );
if( status != PSA_SUCCESS )
return( status );
if( ! PSA_KEY_TYPE_IS_KEY_PAIR( slot->attr.type ) )
return( PSA_ERROR_INVALID_ARGUMENT );
#if defined(MBEDTLS_RSA_C)
if( slot->attr.type == PSA_KEY_TYPE_RSA_KEY_PAIR )
{
mbedtls_rsa_context *rsa = NULL;
status = psa_load_rsa_representation( slot->attr.type,
slot->data.key.data,
slot->data.key.bytes,
&rsa );
if( status != PSA_SUCCESS )
return( status );
if( input_length != mbedtls_rsa_get_len( rsa ) )
{
status = PSA_ERROR_INVALID_ARGUMENT;
goto rsa_exit;
}
#if defined(MBEDTLS_PKCS1_V15)
if( alg == PSA_ALG_RSA_PKCS1V15_CRYPT )
{
status = mbedtls_to_psa_error(
mbedtls_rsa_pkcs1_decrypt( rsa,
mbedtls_ctr_drbg_random,
&global_data.ctr_drbg,
MBEDTLS_RSA_PRIVATE,
output_length,
input,
output,
output_size ) );
}
else
#endif /* MBEDTLS_PKCS1_V15 */
#if defined(MBEDTLS_PKCS1_V21)
if( PSA_ALG_IS_RSA_OAEP( alg ) )
{
psa_rsa_oaep_set_padding_mode( alg, rsa );
status = mbedtls_to_psa_error(
mbedtls_rsa_rsaes_oaep_decrypt( rsa,
mbedtls_ctr_drbg_random,
&global_data.ctr_drbg,
MBEDTLS_RSA_PRIVATE,
salt, salt_length,
output_length,
input,
output,
output_size ) );
}
else
#endif /* MBEDTLS_PKCS1_V21 */
{
status = PSA_ERROR_INVALID_ARGUMENT;
}
rsa_exit:
mbedtls_rsa_free( rsa );
mbedtls_free( rsa );
return( status );
}
else
#endif /* defined(MBEDTLS_RSA_C) */
{
return( PSA_ERROR_NOT_SUPPORTED );
}
}
/****************************************************************/
/* Symmetric cryptography */
/****************************************************************/
static psa_status_t psa_cipher_setup( psa_cipher_operation_t *operation,
psa_key_handle_t handle,
psa_algorithm_t alg,
mbedtls_operation_t cipher_operation )
{
int ret = 0;
psa_status_t status = PSA_ERROR_GENERIC_ERROR;
psa_key_slot_t *slot;
size_t key_bits;
const mbedtls_cipher_info_t *cipher_info = NULL;
psa_key_usage_t usage = ( cipher_operation == MBEDTLS_ENCRYPT ?
PSA_KEY_USAGE_ENCRYPT :
PSA_KEY_USAGE_DECRYPT );
/* A context must be freshly initialized before it can be set up. */
if( operation->alg != 0 )
return( PSA_ERROR_BAD_STATE );
/* The requested algorithm must be one that can be processed by cipher. */
if( ! PSA_ALG_IS_CIPHER( alg ) )
return( PSA_ERROR_INVALID_ARGUMENT );
/* Fetch key material from key storage. */
status = psa_get_key_from_slot( handle, &slot, usage, alg );
if( status != PSA_SUCCESS )
goto exit;
/* Initialize the operation struct members, except for alg. The alg member
* is used to indicate to psa_cipher_abort that there are resources to free,
* so we only set it after resources have been allocated/initialized. */
operation->key_set = 0;
operation->iv_set = 0;
operation->mbedtls_in_use = 0;
operation->iv_size = 0;
operation->block_size = 0;
if( alg == PSA_ALG_ECB_NO_PADDING )
operation->iv_required = 0;
else
operation->iv_required = 1;
/* Try doing the operation through a driver before using software fallback. */
if( cipher_operation == MBEDTLS_ENCRYPT )
status = psa_driver_wrapper_cipher_encrypt_setup( &operation->ctx.driver,
slot,
alg );
else
status = psa_driver_wrapper_cipher_decrypt_setup( &operation->ctx.driver,
slot,
alg );
if( status == PSA_SUCCESS )
{
/* Once the driver context is initialised, it needs to be freed using
* psa_cipher_abort. Indicate this through setting alg. */
operation->alg = alg;
}
if( status != PSA_ERROR_NOT_SUPPORTED ||
psa_key_lifetime_is_external( slot->attr.lifetime ) )
goto exit;
/* Proceed with initializing an mbed TLS cipher context if no driver is
* available for the given algorithm & key. */
mbedtls_cipher_init( &operation->ctx.cipher );
/* Once the cipher context is initialised, it needs to be freed using
* psa_cipher_abort. Indicate there is something to be freed through setting
* alg, and indicate the operation is being done using mbedtls crypto through
* setting mbedtls_in_use. */
operation->alg = alg;
operation->mbedtls_in_use = 1;
key_bits = psa_get_key_slot_bits( slot );
cipher_info = mbedtls_cipher_info_from_psa( alg, slot->attr.type, key_bits, NULL );
if( cipher_info == NULL )
{
status = PSA_ERROR_NOT_SUPPORTED;
goto exit;
}
ret = mbedtls_cipher_setup( &operation->ctx.cipher, cipher_info );
if( ret != 0 )
goto exit;
#if defined(MBEDTLS_DES_C)
if( slot->attr.type == PSA_KEY_TYPE_DES && key_bits == 128 )
{
/* Two-key Triple-DES is 3-key Triple-DES with K1=K3 */
uint8_t keys[24];
memcpy( keys, slot->data.key.data, 16 );
memcpy( keys + 16, slot->data.key.data, 8 );
ret = mbedtls_cipher_setkey( &operation->ctx.cipher,
keys,
192, cipher_operation );
}
else
#endif
{
ret = mbedtls_cipher_setkey( &operation->ctx.cipher,
slot->data.key.data,
(int) key_bits, cipher_operation );
}
if( ret != 0 )
goto exit;
#if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
switch( alg )
{
case PSA_ALG_CBC_NO_PADDING:
ret = mbedtls_cipher_set_padding_mode( &operation->ctx.cipher,
MBEDTLS_PADDING_NONE );
break;
case PSA_ALG_CBC_PKCS7:
ret = mbedtls_cipher_set_padding_mode( &operation->ctx.cipher,
MBEDTLS_PADDING_PKCS7 );
break;
default:
/* The algorithm doesn't involve padding. */
ret = 0;
break;
}
if( ret != 0 )
goto exit;
#endif //MBEDTLS_CIPHER_MODE_WITH_PADDING
operation->block_size = ( PSA_ALG_IS_STREAM_CIPHER( alg ) ? 1 :
PSA_BLOCK_CIPHER_BLOCK_SIZE( slot->attr.type ) );
if( ( alg & PSA_ALG_CIPHER_FROM_BLOCK_FLAG ) != 0 &&
alg != PSA_ALG_ECB_NO_PADDING )
{
operation->iv_size = PSA_BLOCK_CIPHER_BLOCK_SIZE( slot->attr.type );
}
#if defined(MBEDTLS_CHACHA20_C)
else
if( alg == PSA_ALG_CHACHA20 )
operation->iv_size = 12;
#endif
status = PSA_SUCCESS;
exit:
if( ret != 0 )
status = mbedtls_to_psa_error( ret );
if( status == PSA_SUCCESS )
{
/* Update operation flags for both driver and software implementations */
operation->key_set = 1;
}
else
psa_cipher_abort( operation );
return( status );
}
psa_status_t psa_cipher_encrypt_setup( psa_cipher_operation_t *operation,
psa_key_handle_t handle,
psa_algorithm_t alg )
{
return( psa_cipher_setup( operation, handle, alg, MBEDTLS_ENCRYPT ) );
}
psa_status_t psa_cipher_decrypt_setup( psa_cipher_operation_t *operation,
psa_key_handle_t handle,
psa_algorithm_t alg )
{
return( psa_cipher_setup( operation, handle, alg, MBEDTLS_DECRYPT ) );
}
psa_status_t psa_cipher_generate_iv( psa_cipher_operation_t *operation,
uint8_t *iv,
size_t iv_size,
size_t *iv_length )
{
psa_status_t status;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
if( operation->iv_set || ! operation->iv_required )
{
return( PSA_ERROR_BAD_STATE );
}
if( operation->mbedtls_in_use == 0 )
{
status = psa_driver_wrapper_cipher_generate_iv( &operation->ctx.driver,
iv,
iv_size,
iv_length );
goto exit;
}
if( iv_size < operation->iv_size )
{
status = PSA_ERROR_BUFFER_TOO_SMALL;
goto exit;
}
ret = mbedtls_ctr_drbg_random( &global_data.ctr_drbg,
iv, operation->iv_size );
if( ret != 0 )
{
status = mbedtls_to_psa_error( ret );
goto exit;
}
*iv_length = operation->iv_size;
status = psa_cipher_set_iv( operation, iv, *iv_length );
exit:
if( status == PSA_SUCCESS )
operation->iv_set = 1;
else
psa_cipher_abort( operation );
return( status );
}
psa_status_t psa_cipher_set_iv( psa_cipher_operation_t *operation,
const uint8_t *iv,
size_t iv_length )
{
psa_status_t status;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
if( operation->iv_set || ! operation->iv_required )
{
return( PSA_ERROR_BAD_STATE );
}
if( operation->mbedtls_in_use == 0 )
{
status = psa_driver_wrapper_cipher_set_iv( &operation->ctx.driver,
iv,
iv_length );
goto exit;
}
if( iv_length != operation->iv_size )
{
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
ret = mbedtls_cipher_set_iv( &operation->ctx.cipher, iv, iv_length );
status = mbedtls_to_psa_error( ret );
exit:
if( status == PSA_SUCCESS )
operation->iv_set = 1;
else
psa_cipher_abort( operation );
return( status );
}
/* Process input for which the algorithm is set to ECB mode. This requires
* manual processing, since the PSA API is defined as being able to process
* arbitrary-length calls to psa_cipher_update() with ECB mode, but the
* underlying mbedtls_cipher_update only takes full blocks. */
static psa_status_t psa_cipher_update_ecb_internal(
mbedtls_cipher_context_t *ctx,
const uint8_t *input,
size_t input_length,
uint8_t *output,
size_t output_size,
size_t *output_length )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
size_t block_size = ctx->cipher_info->block_size;
size_t internal_output_length = 0;
*output_length = 0;
if( input_length == 0 )
{
status = PSA_SUCCESS;
goto exit;
}
if( ctx->unprocessed_len > 0 )
{
/* Fill up to block size, and run the block if there's a full one. */
size_t bytes_to_copy = block_size - ctx->unprocessed_len;
if( input_length < bytes_to_copy )
bytes_to_copy = input_length;
memcpy( &( ctx->unprocessed_data[ctx->unprocessed_len] ),
input, bytes_to_copy );
input_length -= bytes_to_copy;
input += bytes_to_copy;
ctx->unprocessed_len += bytes_to_copy;
if( ctx->unprocessed_len == block_size )
{
status = mbedtls_to_psa_error(
mbedtls_cipher_update( ctx,
ctx->unprocessed_data,
block_size,
output, &internal_output_length ) );
if( status != PSA_SUCCESS )
goto exit;
output += internal_output_length;
output_size -= internal_output_length;
*output_length += internal_output_length;
ctx->unprocessed_len = 0;
}
}
while( input_length >= block_size )
{
/* Run all full blocks we have, one by one */
status = mbedtls_to_psa_error(
mbedtls_cipher_update( ctx, input,
block_size,
output, &internal_output_length ) );
if( status != PSA_SUCCESS )
goto exit;
input_length -= block_size;
input += block_size;
output += internal_output_length;
output_size -= internal_output_length;
*output_length += internal_output_length;
}
if( input_length > 0 )
{
/* Save unprocessed bytes for later processing */
memcpy( &( ctx->unprocessed_data[ctx->unprocessed_len] ),
input, input_length );
ctx->unprocessed_len += input_length;
}
status = PSA_SUCCESS;
exit:
return( status );
}
psa_status_t psa_cipher_update( psa_cipher_operation_t *operation,
const uint8_t *input,
size_t input_length,
uint8_t *output,
size_t output_size,
size_t *output_length )
{
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
size_t expected_output_size;
if( operation->alg == 0 )
{
return( PSA_ERROR_BAD_STATE );
}
if( operation->iv_required && ! operation->iv_set )
{
return( PSA_ERROR_BAD_STATE );
}
if( operation->mbedtls_in_use == 0 )
{
status = psa_driver_wrapper_cipher_update( &operation->ctx.driver,
input,
input_length,
output,
output_size,
output_length );
goto exit;
}
if( ! PSA_ALG_IS_STREAM_CIPHER( operation->alg ) )
{
/* Take the unprocessed partial block left over from previous
* update calls, if any, plus the input to this call. Remove
* the last partial block, if any. You get the data that will be
* output in this call. */
expected_output_size =
( operation->ctx.cipher.unprocessed_len + input_length )
/ operation->block_size * operation->block_size;
}
else
{
expected_output_size = input_length;
}
if( output_size < expected_output_size )
{
status = PSA_ERROR_BUFFER_TOO_SMALL;
goto exit;
}
if( operation->alg == PSA_ALG_ECB_NO_PADDING )
{
/* mbedtls_cipher_update has an API inconsistency: it will only
* process a single block at a time in ECB mode. Abstract away that
* inconsistency here to match the PSA API behaviour. */
status = psa_cipher_update_ecb_internal( &operation->ctx.cipher,
input,
input_length,
output,
output_size,
output_length );
}
else
{
status = mbedtls_to_psa_error(
mbedtls_cipher_update( &operation->ctx.cipher, input,
input_length, output, output_length ) );
}
exit:
if( status != PSA_SUCCESS )
psa_cipher_abort( operation );
return( status );
}
psa_status_t psa_cipher_finish( psa_cipher_operation_t *operation,
uint8_t *output,
size_t output_size,
size_t *output_length )
{
psa_status_t status = PSA_ERROR_GENERIC_ERROR;
uint8_t temp_output_buffer[MBEDTLS_MAX_BLOCK_LENGTH];
if( operation->alg == 0 )
{
return( PSA_ERROR_BAD_STATE );
}
if( operation->iv_required && ! operation->iv_set )
{
return( PSA_ERROR_BAD_STATE );
}
if( operation->mbedtls_in_use == 0 )
{
status = psa_driver_wrapper_cipher_finish( &operation->ctx.driver,
output,
output_size,
output_length );
goto exit;
}
if( operation->ctx.cipher.unprocessed_len != 0 )
{
if( operation->alg == PSA_ALG_ECB_NO_PADDING ||
operation->alg == PSA_ALG_CBC_NO_PADDING )
{
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
}
status = mbedtls_to_psa_error(
mbedtls_cipher_finish( &operation->ctx.cipher,
temp_output_buffer,
output_length ) );
if( status != PSA_SUCCESS )
goto exit;
if( *output_length == 0 )
; /* Nothing to copy. Note that output may be NULL in this case. */
else if( output_size >= *output_length )
memcpy( output, temp_output_buffer, *output_length );
else
status = PSA_ERROR_BUFFER_TOO_SMALL;
exit:
if( operation->mbedtls_in_use == 1 )
mbedtls_platform_zeroize( temp_output_buffer, sizeof( temp_output_buffer ) );
if( status == PSA_SUCCESS )
return( psa_cipher_abort( operation ) );
else
{
*output_length = 0;
(void) psa_cipher_abort( operation );
return( status );
}
}
psa_status_t psa_cipher_abort( psa_cipher_operation_t *operation )
{
if( operation->alg == 0 )
{
/* The object has (apparently) been initialized but it is not (yet)
* in use. It's ok to call abort on such an object, and there's
* nothing to do. */
return( PSA_SUCCESS );
}
/* Sanity check (shouldn't happen: operation->alg should
* always have been initialized to a valid value). */
if( ! PSA_ALG_IS_CIPHER( operation->alg ) )
return( PSA_ERROR_BAD_STATE );
if( operation->mbedtls_in_use == 0 )
psa_driver_wrapper_cipher_abort( &operation->ctx.driver );
else
mbedtls_cipher_free( &operation->ctx.cipher );
operation->alg = 0;
operation->key_set = 0;
operation->iv_set = 0;
operation->mbedtls_in_use = 0;
operation->iv_size = 0;
operation->block_size = 0;
operation->iv_required = 0;
return( PSA_SUCCESS );
}
/****************************************************************/
/* AEAD */
/****************************************************************/
typedef struct
{
psa_key_slot_t *slot;
const mbedtls_cipher_info_t *cipher_info;
union
{
#if defined(MBEDTLS_CCM_C)
mbedtls_ccm_context ccm;
#endif /* MBEDTLS_CCM_C */
#if defined(MBEDTLS_GCM_C)
mbedtls_gcm_context gcm;
#endif /* MBEDTLS_GCM_C */
#if defined(MBEDTLS_CHACHAPOLY_C)
mbedtls_chachapoly_context chachapoly;
#endif /* MBEDTLS_CHACHAPOLY_C */
} ctx;
psa_algorithm_t core_alg;
uint8_t full_tag_length;
uint8_t tag_length;
} aead_operation_t;
static void psa_aead_abort_internal( aead_operation_t *operation )
{
switch( operation->core_alg )
{
#if defined(MBEDTLS_CCM_C)
case PSA_ALG_CCM:
mbedtls_ccm_free( &operation->ctx.ccm );
break;
#endif /* MBEDTLS_CCM_C */
#if defined(MBEDTLS_GCM_C)
case PSA_ALG_GCM:
mbedtls_gcm_free( &operation->ctx.gcm );
break;
#endif /* MBEDTLS_GCM_C */
}
}
static psa_status_t psa_aead_setup( aead_operation_t *operation,
psa_key_handle_t handle,
psa_key_usage_t usage,
psa_algorithm_t alg )
{
psa_status_t status;
size_t key_bits;
mbedtls_cipher_id_t cipher_id;
status = psa_get_transparent_key( handle, &operation->slot, usage, alg );
if( status != PSA_SUCCESS )
return( status );
key_bits = psa_get_key_slot_bits( operation->slot );
operation->cipher_info =
mbedtls_cipher_info_from_psa( alg, operation->slot->attr.type, key_bits,
&cipher_id );
if( operation->cipher_info == NULL )
return( PSA_ERROR_NOT_SUPPORTED );
switch( PSA_ALG_AEAD_WITH_TAG_LENGTH( alg, 0 ) )
{
#if defined(MBEDTLS_CCM_C)
case PSA_ALG_AEAD_WITH_TAG_LENGTH( PSA_ALG_CCM, 0 ):
operation->core_alg = PSA_ALG_CCM;
operation->full_tag_length = 16;
/* CCM allows the following tag lengths: 4, 6, 8, 10, 12, 14, 16.
* The call to mbedtls_ccm_encrypt_and_tag or
* mbedtls_ccm_auth_decrypt will validate the tag length. */
if( PSA_BLOCK_CIPHER_BLOCK_SIZE( operation->slot->attr.type ) != 16 )
return( PSA_ERROR_INVALID_ARGUMENT );
mbedtls_ccm_init( &operation->ctx.ccm );
status = mbedtls_to_psa_error(
mbedtls_ccm_setkey( &operation->ctx.ccm, cipher_id,
operation->slot->data.key.data,
(unsigned int) key_bits ) );
if( status != 0 )
goto cleanup;
break;
#endif /* MBEDTLS_CCM_C */
#if defined(MBEDTLS_GCM_C)
case PSA_ALG_AEAD_WITH_TAG_LENGTH( PSA_ALG_GCM, 0 ):
operation->core_alg = PSA_ALG_GCM;
operation->full_tag_length = 16;
/* GCM allows the following tag lengths: 4, 8, 12, 13, 14, 15, 16.
* The call to mbedtls_gcm_crypt_and_tag or
* mbedtls_gcm_auth_decrypt will validate the tag length. */
if( PSA_BLOCK_CIPHER_BLOCK_SIZE( operation->slot->attr.type ) != 16 )
return( PSA_ERROR_INVALID_ARGUMENT );
mbedtls_gcm_init( &operation->ctx.gcm );
status = mbedtls_to_psa_error(
mbedtls_gcm_setkey( &operation->ctx.gcm, cipher_id,
operation->slot->data.key.data,
(unsigned int) key_bits ) );
if( status != 0 )
goto cleanup;
break;
#endif /* MBEDTLS_GCM_C */
#if defined(MBEDTLS_CHACHAPOLY_C)
case PSA_ALG_AEAD_WITH_TAG_LENGTH( PSA_ALG_CHACHA20_POLY1305, 0 ):
operation->core_alg = PSA_ALG_CHACHA20_POLY1305;
operation->full_tag_length = 16;
/* We only support the default tag length. */
if( alg != PSA_ALG_CHACHA20_POLY1305 )
return( PSA_ERROR_NOT_SUPPORTED );
mbedtls_chachapoly_init( &operation->ctx.chachapoly );
status = mbedtls_to_psa_error(
mbedtls_chachapoly_setkey( &operation->ctx.chachapoly,
operation->slot->data.key.data ) );
if( status != 0 )
goto cleanup;
break;
#endif /* MBEDTLS_CHACHAPOLY_C */
default:
return( PSA_ERROR_NOT_SUPPORTED );
}
if( PSA_AEAD_TAG_LENGTH( alg ) > operation->full_tag_length )
{
status = PSA_ERROR_INVALID_ARGUMENT;
goto cleanup;
}
operation->tag_length = PSA_AEAD_TAG_LENGTH( alg );
return( PSA_SUCCESS );
cleanup:
psa_aead_abort_internal( operation );
return( status );
}
psa_status_t psa_aead_encrypt( psa_key_handle_t handle,
psa_algorithm_t alg,
const uint8_t *nonce,
size_t nonce_length,
const uint8_t *additional_data,
size_t additional_data_length,
const uint8_t *plaintext,
size_t plaintext_length,
uint8_t *ciphertext,
size_t ciphertext_size,
size_t *ciphertext_length )
{
psa_status_t status;
aead_operation_t operation;
uint8_t *tag;
*ciphertext_length = 0;
status = psa_aead_setup( &operation, handle, PSA_KEY_USAGE_ENCRYPT, alg );
if( status != PSA_SUCCESS )
return( status );
/* For all currently supported modes, the tag is at the end of the
* ciphertext. */
if( ciphertext_size < ( plaintext_length + operation.tag_length ) )
{
status = PSA_ERROR_BUFFER_TOO_SMALL;
goto exit;
}
tag = ciphertext + plaintext_length;
#if defined(MBEDTLS_GCM_C)
if( operation.core_alg == PSA_ALG_GCM )
{
status = mbedtls_to_psa_error(
mbedtls_gcm_crypt_and_tag( &operation.ctx.gcm,
MBEDTLS_GCM_ENCRYPT,
plaintext_length,
nonce, nonce_length,
additional_data, additional_data_length,
plaintext, ciphertext,
operation.tag_length, tag ) );
}
else
#endif /* MBEDTLS_GCM_C */
#if defined(MBEDTLS_CCM_C)
if( operation.core_alg == PSA_ALG_CCM )
{
status = mbedtls_to_psa_error(
mbedtls_ccm_encrypt_and_tag( &operation.ctx.ccm,
plaintext_length,
nonce, nonce_length,
additional_data,
additional_data_length,
plaintext, ciphertext,
tag, operation.tag_length ) );
}
else
#endif /* MBEDTLS_CCM_C */
#if defined(MBEDTLS_CHACHAPOLY_C)
if( operation.core_alg == PSA_ALG_CHACHA20_POLY1305 )
{
if( nonce_length != 12 || operation.tag_length != 16 )
{
status = PSA_ERROR_NOT_SUPPORTED;
goto exit;
}
status = mbedtls_to_psa_error(
mbedtls_chachapoly_encrypt_and_tag( &operation.ctx.chachapoly,
plaintext_length,
nonce,
additional_data,
additional_data_length,
plaintext,
ciphertext,
tag ) );
}
else
#endif /* MBEDTLS_CHACHAPOLY_C */
{
return( PSA_ERROR_NOT_SUPPORTED );
}
if( status != PSA_SUCCESS && ciphertext_size != 0 )
memset( ciphertext, 0, ciphertext_size );
exit:
psa_aead_abort_internal( &operation );
if( status == PSA_SUCCESS )
*ciphertext_length = plaintext_length + operation.tag_length;
return( status );
}
/* Locate the tag in a ciphertext buffer containing the encrypted data
* followed by the tag. Return the length of the part preceding the tag in
* *plaintext_length. This is the size of the plaintext in modes where
* the encrypted data has the same size as the plaintext, such as
* CCM and GCM. */
static psa_status_t psa_aead_unpadded_locate_tag( size_t tag_length,
const uint8_t *ciphertext,
size_t ciphertext_length,
size_t plaintext_size,
const uint8_t **p_tag )
{
size_t payload_length;
if( tag_length > ciphertext_length )
return( PSA_ERROR_INVALID_ARGUMENT );
payload_length = ciphertext_length - tag_length;
if( payload_length > plaintext_size )
return( PSA_ERROR_BUFFER_TOO_SMALL );
*p_tag = ciphertext + payload_length;
return( PSA_SUCCESS );
}
psa_status_t psa_aead_decrypt( psa_key_handle_t handle,
psa_algorithm_t alg,
const uint8_t *nonce,
size_t nonce_length,
const uint8_t *additional_data,
size_t additional_data_length,
const uint8_t *ciphertext,
size_t ciphertext_length,
uint8_t *plaintext,
size_t plaintext_size,
size_t *plaintext_length )
{
psa_status_t status;
aead_operation_t operation;
const uint8_t *tag = NULL;
*plaintext_length = 0;
status = psa_aead_setup( &operation, handle, PSA_KEY_USAGE_DECRYPT, alg );
if( status != PSA_SUCCESS )
return( status );
status = psa_aead_unpadded_locate_tag( operation.tag_length,
ciphertext, ciphertext_length,
plaintext_size, &tag );
if( status != PSA_SUCCESS )
goto exit;
#if defined(MBEDTLS_GCM_C)
if( operation.core_alg == PSA_ALG_GCM )
{
status = mbedtls_to_psa_error(
mbedtls_gcm_auth_decrypt( &operation.ctx.gcm,
ciphertext_length - operation.tag_length,
nonce, nonce_length,
additional_data,
additional_data_length,
tag, operation.tag_length,
ciphertext, plaintext ) );
}
else
#endif /* MBEDTLS_GCM_C */
#if defined(MBEDTLS_CCM_C)
if( operation.core_alg == PSA_ALG_CCM )
{
status = mbedtls_to_psa_error(
mbedtls_ccm_auth_decrypt( &operation.ctx.ccm,
ciphertext_length - operation.tag_length,
nonce, nonce_length,
additional_data,
additional_data_length,
ciphertext, plaintext,
tag, operation.tag_length ) );
}
else
#endif /* MBEDTLS_CCM_C */
#if defined(MBEDTLS_CHACHAPOLY_C)
if( operation.core_alg == PSA_ALG_CHACHA20_POLY1305 )
{
if( nonce_length != 12 || operation.tag_length != 16 )
{
status = PSA_ERROR_NOT_SUPPORTED;
goto exit;
}
status = mbedtls_to_psa_error(
mbedtls_chachapoly_auth_decrypt( &operation.ctx.chachapoly,
ciphertext_length - operation.tag_length,
nonce,
additional_data,
additional_data_length,
tag,
ciphertext,
plaintext ) );
}
else
#endif /* MBEDTLS_CHACHAPOLY_C */
{
return( PSA_ERROR_NOT_SUPPORTED );
}
if( status != PSA_SUCCESS && plaintext_size != 0 )
memset( plaintext, 0, plaintext_size );
exit:
psa_aead_abort_internal( &operation );
if( status == PSA_SUCCESS )
*plaintext_length = ciphertext_length - operation.tag_length;
return( status );
}
/****************************************************************/
/* Generators */
/****************************************************************/
#define HKDF_STATE_INIT 0 /* no input yet */
#define HKDF_STATE_STARTED 1 /* got salt */
#define HKDF_STATE_KEYED 2 /* got key */
#define HKDF_STATE_OUTPUT 3 /* output started */
static psa_algorithm_t psa_key_derivation_get_kdf_alg(
const psa_key_derivation_operation_t *operation )
{
if ( PSA_ALG_IS_KEY_AGREEMENT( operation->alg ) )
return( PSA_ALG_KEY_AGREEMENT_GET_KDF( operation->alg ) );
else
return( operation->alg );
}
psa_status_t psa_key_derivation_abort( psa_key_derivation_operation_t *operation )
{
psa_status_t status = PSA_SUCCESS;
psa_algorithm_t kdf_alg = psa_key_derivation_get_kdf_alg( operation );
if( kdf_alg == 0 )
{
/* The object has (apparently) been initialized but it is not
* in use. It's ok to call abort on such an object, and there's
* nothing to do. */
}
else
#if defined(MBEDTLS_MD_C)
if( PSA_ALG_IS_HKDF( kdf_alg ) )
{
mbedtls_free( operation->ctx.hkdf.info );
status = psa_hmac_abort_internal( &operation->ctx.hkdf.hmac );
}
else if( PSA_ALG_IS_TLS12_PRF( kdf_alg ) ||
/* TLS-1.2 PSK-to-MS KDF uses the same core as TLS-1.2 PRF */
PSA_ALG_IS_TLS12_PSK_TO_MS( kdf_alg ) )
{
if( operation->ctx.tls12_prf.seed != NULL )
{
mbedtls_platform_zeroize( operation->ctx.tls12_prf.seed,
operation->ctx.tls12_prf.seed_length );
mbedtls_free( operation->ctx.tls12_prf.seed );
}
if( operation->ctx.tls12_prf.label != NULL )
{
mbedtls_platform_zeroize( operation->ctx.tls12_prf.label,
operation->ctx.tls12_prf.label_length );
mbedtls_free( operation->ctx.tls12_prf.label );
}
status = psa_hmac_abort_internal( &operation->ctx.tls12_prf.hmac );
/* We leave the fields Ai and output_block to be erased safely by the
* mbedtls_platform_zeroize() in the end of this function. */
}
else
#endif /* MBEDTLS_MD_C */
{
status = PSA_ERROR_BAD_STATE;
}
mbedtls_platform_zeroize( operation, sizeof( *operation ) );
return( status );
}
psa_status_t psa_key_derivation_get_capacity(const psa_key_derivation_operation_t *operation,
size_t *capacity)
{
if( operation->alg == 0 )
{
/* This is a blank key derivation operation. */
return( PSA_ERROR_BAD_STATE );
}
*capacity = operation->capacity;
return( PSA_SUCCESS );
}
psa_status_t psa_key_derivation_set_capacity( psa_key_derivation_operation_t *operation,
size_t capacity )
{
if( operation->alg == 0 )
return( PSA_ERROR_BAD_STATE );
if( capacity > operation->capacity )
return( PSA_ERROR_INVALID_ARGUMENT );
operation->capacity = capacity;
return( PSA_SUCCESS );
}
#if defined(MBEDTLS_MD_C)
/* Read some bytes from an HKDF-based operation. This performs a chunk
* of the expand phase of the HKDF algorithm. */
static psa_status_t psa_key_derivation_hkdf_read( psa_hkdf_key_derivation_t *hkdf,
psa_algorithm_t hash_alg,
uint8_t *output,
size_t output_length )
{
uint8_t hash_length = PSA_HASH_SIZE( hash_alg );
psa_status_t status;
if( hkdf->state < HKDF_STATE_KEYED || ! hkdf->info_set )
return( PSA_ERROR_BAD_STATE );
hkdf->state = HKDF_STATE_OUTPUT;
while( output_length != 0 )
{
/* Copy what remains of the current block */
uint8_t n = hash_length - hkdf->offset_in_block;
if( n > output_length )
n = (uint8_t) output_length;
memcpy( output, hkdf->output_block + hkdf->offset_in_block, n );
output += n;
output_length -= n;
hkdf->offset_in_block += n;
if( output_length == 0 )
break;
/* We can't be wanting more output after block 0xff, otherwise
* the capacity check in psa_key_derivation_output_bytes() would have
* prevented this call. It could happen only if the operation
* object was corrupted or if this function is called directly
* inside the library. */
if( hkdf->block_number == 0xff )
return( PSA_ERROR_BAD_STATE );
/* We need a new block */
++hkdf->block_number;
hkdf->offset_in_block = 0;
status = psa_hmac_setup_internal( &hkdf->hmac,
hkdf->prk, hash_length,
hash_alg );
if( status != PSA_SUCCESS )
return( status );
if( hkdf->block_number != 1 )
{
status = psa_hash_update( &hkdf->hmac.hash_ctx,
hkdf->output_block,
hash_length );
if( status != PSA_SUCCESS )
return( status );
}
status = psa_hash_update( &hkdf->hmac.hash_ctx,
hkdf->info,
hkdf->info_length );
if( status != PSA_SUCCESS )
return( status );
status = psa_hash_update( &hkdf->hmac.hash_ctx,
&hkdf->block_number, 1 );
if( status != PSA_SUCCESS )
return( status );
status = psa_hmac_finish_internal( &hkdf->hmac,
hkdf->output_block,
sizeof( hkdf->output_block ) );
if( status != PSA_SUCCESS )
return( status );
}
return( PSA_SUCCESS );
}
static psa_status_t psa_key_derivation_tls12_prf_generate_next_block(
psa_tls12_prf_key_derivation_t *tls12_prf,
psa_algorithm_t alg )
{
psa_algorithm_t hash_alg = PSA_ALG_HKDF_GET_HASH( alg );
uint8_t hash_length = PSA_HASH_SIZE( hash_alg );
psa_hash_operation_t backup = PSA_HASH_OPERATION_INIT;
psa_status_t status, cleanup_status;
/* We can't be wanting more output after block 0xff, otherwise
* the capacity check in psa_key_derivation_output_bytes() would have
* prevented this call. It could happen only if the operation
* object was corrupted or if this function is called directly
* inside the library. */
if( tls12_prf->block_number == 0xff )
return( PSA_ERROR_CORRUPTION_DETECTED );
/* We need a new block */
++tls12_prf->block_number;
tls12_prf->left_in_block = hash_length;
/* Recall the definition of the TLS-1.2-PRF from RFC 5246:
*
* PRF(secret, label, seed) = P_<hash>(secret, label + seed)
*
* P_hash(secret, seed) = HMAC_hash(secret, A(1) + seed) +
* HMAC_hash(secret, A(2) + seed) +
* HMAC_hash(secret, A(3) + seed) + ...
*
* A(0) = seed
* A(i) = HMAC_hash(secret, A(i-1))
*
* The `psa_tls12_prf_key_derivation` structure saves the block
* `HMAC_hash(secret, A(i) + seed)` from which the output
* is currently extracted as `output_block` and where i is
* `block_number`.
*/
/* Save the hash context before using it, to preserve the hash state with
* only the inner padding in it. We need this, because inner padding depends
* on the key (secret in the RFC's terminology). */
status = psa_hash_clone( &tls12_prf->hmac.hash_ctx, &backup );
if( status != PSA_SUCCESS )
goto cleanup;
/* Calculate A(i) where i = tls12_prf->block_number. */
if( tls12_prf->block_number == 1 )
{
/* A(1) = HMAC_hash(secret, A(0)), where A(0) = seed. (The RFC overloads
* the variable seed and in this instance means it in the context of the
* P_hash function, where seed = label + seed.) */
status = psa_hash_update( &tls12_prf->hmac.hash_ctx,
tls12_prf->label, tls12_prf->label_length );
if( status != PSA_SUCCESS )
goto cleanup;
status = psa_hash_update( &tls12_prf->hmac.hash_ctx,
tls12_prf->seed, tls12_prf->seed_length );
if( status != PSA_SUCCESS )
goto cleanup;
}
else
{
/* A(i) = HMAC_hash(secret, A(i-1)) */
status = psa_hash_update( &tls12_prf->hmac.hash_ctx,
tls12_prf->Ai, hash_length );
if( status != PSA_SUCCESS )
goto cleanup;
}
status = psa_hmac_finish_internal( &tls12_prf->hmac,
tls12_prf->Ai, hash_length );
if( status != PSA_SUCCESS )
goto cleanup;
status = psa_hash_clone( &backup, &tls12_prf->hmac.hash_ctx );
if( status != PSA_SUCCESS )
goto cleanup;
/* Calculate HMAC_hash(secret, A(i) + label + seed). */
status = psa_hash_update( &tls12_prf->hmac.hash_ctx,
tls12_prf->Ai, hash_length );
if( status != PSA_SUCCESS )
goto cleanup;
status = psa_hash_update( &tls12_prf->hmac.hash_ctx,
tls12_prf->label, tls12_prf->label_length );
if( status != PSA_SUCCESS )
goto cleanup;
status = psa_hash_update( &tls12_prf->hmac.hash_ctx,
tls12_prf->seed, tls12_prf->seed_length );
if( status != PSA_SUCCESS )
goto cleanup;
status = psa_hmac_finish_internal( &tls12_prf->hmac,
tls12_prf->output_block, hash_length );
if( status != PSA_SUCCESS )
goto cleanup;
status = psa_hash_clone( &backup, &tls12_prf->hmac.hash_ctx );
if( status != PSA_SUCCESS )
goto cleanup;
cleanup:
cleanup_status = psa_hash_abort( &backup );
if( status == PSA_SUCCESS && cleanup_status != PSA_SUCCESS )
status = cleanup_status;
return( status );
}
static psa_status_t psa_key_derivation_tls12_prf_read(
psa_tls12_prf_key_derivation_t *tls12_prf,
psa_algorithm_t alg,
uint8_t *output,
size_t output_length )
{
psa_algorithm_t hash_alg = PSA_ALG_TLS12_PRF_GET_HASH( alg );
uint8_t hash_length = PSA_HASH_SIZE( hash_alg );
psa_status_t status;
uint8_t offset, length;
while( output_length != 0 )
{
/* Check if we have fully processed the current block. */
if( tls12_prf->left_in_block == 0 )
{
status = psa_key_derivation_tls12_prf_generate_next_block( tls12_prf,
alg );
if( status != PSA_SUCCESS )
return( status );
continue;
}
if( tls12_prf->left_in_block > output_length )
length = (uint8_t) output_length;
else
length = tls12_prf->left_in_block;
offset = hash_length - tls12_prf->left_in_block;
memcpy( output, tls12_prf->output_block + offset, length );
output += length;
output_length -= length;
tls12_prf->left_in_block -= length;
}
return( PSA_SUCCESS );
}
#endif /* MBEDTLS_MD_C */
psa_status_t psa_key_derivation_output_bytes(
psa_key_derivation_operation_t *operation,
uint8_t *output,
size_t output_length )
{
psa_status_t status;
psa_algorithm_t kdf_alg = psa_key_derivation_get_kdf_alg( operation );
if( operation->alg == 0 )
{
/* This is a blank operation. */
return( PSA_ERROR_BAD_STATE );
}
if( output_length > operation->capacity )
{
operation->capacity = 0;
/* Go through the error path to wipe all confidential data now
* that the operation object is useless. */
status = PSA_ERROR_INSUFFICIENT_DATA;
goto exit;
}
if( output_length == 0 && operation->capacity == 0 )
{
/* Edge case: this is a finished operation, and 0 bytes
* were requested. The right error in this case could
* be either INSUFFICIENT_CAPACITY or BAD_STATE. Return
* INSUFFICIENT_CAPACITY, which is right for a finished
* operation, for consistency with the case when
* output_length > 0. */
return( PSA_ERROR_INSUFFICIENT_DATA );
}
operation->capacity -= output_length;
#if defined(MBEDTLS_MD_C)
if( PSA_ALG_IS_HKDF( kdf_alg ) )
{
psa_algorithm_t hash_alg = PSA_ALG_HKDF_GET_HASH( kdf_alg );
status = psa_key_derivation_hkdf_read( &operation->ctx.hkdf, hash_alg,
output, output_length );
}
else
if( PSA_ALG_IS_TLS12_PRF( kdf_alg ) ||
PSA_ALG_IS_TLS12_PSK_TO_MS( kdf_alg ) )
{
status = psa_key_derivation_tls12_prf_read( &operation->ctx.tls12_prf,
kdf_alg, output,
output_length );
}
else
#endif /* MBEDTLS_MD_C */
{
return( PSA_ERROR_BAD_STATE );
}
exit:
if( status != PSA_SUCCESS )
{
/* Preserve the algorithm upon errors, but clear all sensitive state.
* This allows us to differentiate between exhausted operations and
* blank operations, so we can return PSA_ERROR_BAD_STATE on blank
* operations. */
psa_algorithm_t alg = operation->alg;
psa_key_derivation_abort( operation );
operation->alg = alg;
memset( output, '!', output_length );
}
return( status );
}
#if defined(MBEDTLS_DES_C)
static void psa_des_set_key_parity( uint8_t *data, size_t data_size )
{
if( data_size >= 8 )
mbedtls_des_key_set_parity( data );
if( data_size >= 16 )
mbedtls_des_key_set_parity( data + 8 );
if( data_size >= 24 )
mbedtls_des_key_set_parity( data + 16 );
}
#endif /* MBEDTLS_DES_C */
static psa_status_t psa_generate_derived_key_internal(
psa_key_slot_t *slot,
size_t bits,
psa_key_derivation_operation_t *operation )
{
uint8_t *data = NULL;
size_t bytes = PSA_BITS_TO_BYTES( bits );
psa_status_t status;
if( ! key_type_is_raw_bytes( slot->attr.type ) )
return( PSA_ERROR_INVALID_ARGUMENT );
if( bits % 8 != 0 )
return( PSA_ERROR_INVALID_ARGUMENT );
data = mbedtls_calloc( 1, bytes );
if( data == NULL )
return( PSA_ERROR_INSUFFICIENT_MEMORY );
status = psa_key_derivation_output_bytes( operation, data, bytes );
if( status != PSA_SUCCESS )
goto exit;
#if defined(MBEDTLS_DES_C)
if( slot->attr.type == PSA_KEY_TYPE_DES )
psa_des_set_key_parity( data, bytes );
#endif /* MBEDTLS_DES_C */
status = psa_import_key_into_slot( slot, data, bytes );
exit:
mbedtls_free( data );
return( status );
}
psa_status_t psa_key_derivation_output_key( const psa_key_attributes_t *attributes,
psa_key_derivation_operation_t *operation,
psa_key_handle_t *handle )
{
psa_status_t status;
psa_key_slot_t *slot = NULL;
psa_se_drv_table_entry_t *driver = NULL;
/* Reject any attempt to create a zero-length key so that we don't
* risk tripping up later, e.g. on a malloc(0) that returns NULL. */
if( psa_get_key_bits( attributes ) == 0 )
return( PSA_ERROR_INVALID_ARGUMENT );
if( ! operation->can_output_key )
return( PSA_ERROR_NOT_PERMITTED );
status = psa_start_key_creation( PSA_KEY_CREATION_DERIVE,
attributes, handle, &slot, &driver );
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
if( driver != NULL )
{
/* Deriving a key in a secure element is not implemented yet. */
status = PSA_ERROR_NOT_SUPPORTED;
}
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
if( status == PSA_SUCCESS )
{
status = psa_generate_derived_key_internal( slot,
attributes->core.bits,
operation );
}
if( status == PSA_SUCCESS )
status = psa_finish_key_creation( slot, driver );
if( status != PSA_SUCCESS )
{
psa_fail_key_creation( slot, driver );
*handle = 0;
}
return( status );
}
/****************************************************************/
/* Key derivation */
/****************************************************************/
static psa_status_t psa_key_derivation_setup_kdf(
psa_key_derivation_operation_t *operation,
psa_algorithm_t kdf_alg )
{
/* Make sure that operation->ctx is properly zero-initialised. (Macro
* initialisers for this union leave some bytes unspecified.) */
memset( &operation->ctx, 0, sizeof( operation->ctx ) );
/* Make sure that kdf_alg is a supported key derivation algorithm. */
#if defined(MBEDTLS_MD_C)
if( PSA_ALG_IS_HKDF( kdf_alg ) ||
PSA_ALG_IS_TLS12_PRF( kdf_alg ) ||
PSA_ALG_IS_TLS12_PSK_TO_MS( kdf_alg ) )
{
psa_algorithm_t hash_alg = PSA_ALG_HKDF_GET_HASH( kdf_alg );
size_t hash_size = PSA_HASH_SIZE( hash_alg );
if( hash_size == 0 )
return( PSA_ERROR_NOT_SUPPORTED );
if( ( PSA_ALG_IS_TLS12_PRF( kdf_alg ) ||
PSA_ALG_IS_TLS12_PSK_TO_MS( kdf_alg ) ) &&
! ( hash_alg == PSA_ALG_SHA_256 || hash_alg == PSA_ALG_SHA_384 ) )
{
return( PSA_ERROR_NOT_SUPPORTED );
}
operation->capacity = 255 * hash_size;
return( PSA_SUCCESS );
}
#endif /* MBEDTLS_MD_C */
else
return( PSA_ERROR_NOT_SUPPORTED );
}
psa_status_t psa_key_derivation_setup( psa_key_derivation_operation_t *operation,
psa_algorithm_t alg )
{
psa_status_t status;
if( operation->alg != 0 )
return( PSA_ERROR_BAD_STATE );
if( PSA_ALG_IS_RAW_KEY_AGREEMENT( alg ) )
return( PSA_ERROR_INVALID_ARGUMENT );
else if( PSA_ALG_IS_KEY_AGREEMENT( alg ) )
{
psa_algorithm_t kdf_alg = PSA_ALG_KEY_AGREEMENT_GET_KDF( alg );
status = psa_key_derivation_setup_kdf( operation, kdf_alg );
}
else if( PSA_ALG_IS_KEY_DERIVATION( alg ) )
{
status = psa_key_derivation_setup_kdf( operation, alg );
}
else
return( PSA_ERROR_INVALID_ARGUMENT );
if( status == PSA_SUCCESS )
operation->alg = alg;
return( status );
}
#if defined(MBEDTLS_MD_C)
static psa_status_t psa_hkdf_input( psa_hkdf_key_derivation_t *hkdf,
psa_algorithm_t hash_alg,
psa_key_derivation_step_t step,
const uint8_t *data,
size_t data_length )
{
psa_status_t status;
switch( step )
{
case PSA_KEY_DERIVATION_INPUT_SALT:
if( hkdf->state != HKDF_STATE_INIT )
return( PSA_ERROR_BAD_STATE );
status = psa_hmac_setup_internal( &hkdf->hmac,
data, data_length,
hash_alg );
if( status != PSA_SUCCESS )
return( status );
hkdf->state = HKDF_STATE_STARTED;
return( PSA_SUCCESS );
case PSA_KEY_DERIVATION_INPUT_SECRET:
/* If no salt was provided, use an empty salt. */
if( hkdf->state == HKDF_STATE_INIT )
{
status = psa_hmac_setup_internal( &hkdf->hmac,
NULL, 0,
hash_alg );
if( status != PSA_SUCCESS )
return( status );
hkdf->state = HKDF_STATE_STARTED;
}
if( hkdf->state != HKDF_STATE_STARTED )
return( PSA_ERROR_BAD_STATE );
status = psa_hash_update( &hkdf->hmac.hash_ctx,
data, data_length );
if( status != PSA_SUCCESS )
return( status );
status = psa_hmac_finish_internal( &hkdf->hmac,
hkdf->prk,
sizeof( hkdf->prk ) );
if( status != PSA_SUCCESS )
return( status );
hkdf->offset_in_block = PSA_HASH_SIZE( hash_alg );
hkdf->block_number = 0;
hkdf->state = HKDF_STATE_KEYED;
return( PSA_SUCCESS );
case PSA_KEY_DERIVATION_INPUT_INFO:
if( hkdf->state == HKDF_STATE_OUTPUT )
return( PSA_ERROR_BAD_STATE );
if( hkdf->info_set )
return( PSA_ERROR_BAD_STATE );
hkdf->info_length = data_length;
if( data_length != 0 )
{
hkdf->info = mbedtls_calloc( 1, data_length );
if( hkdf->info == NULL )
return( PSA_ERROR_INSUFFICIENT_MEMORY );
memcpy( hkdf->info, data, data_length );
}
hkdf->info_set = 1;
return( PSA_SUCCESS );
default:
return( PSA_ERROR_INVALID_ARGUMENT );
}
}
static psa_status_t psa_tls12_prf_set_seed( psa_tls12_prf_key_derivation_t *prf,
const uint8_t *data,
size_t data_length )
{
if( prf->state != TLS12_PRF_STATE_INIT )
return( PSA_ERROR_BAD_STATE );
if( data_length != 0 )
{
prf->seed = mbedtls_calloc( 1, data_length );
if( prf->seed == NULL )
return( PSA_ERROR_INSUFFICIENT_MEMORY );
memcpy( prf->seed, data, data_length );
prf->seed_length = data_length;
}
prf->state = TLS12_PRF_STATE_SEED_SET;
return( PSA_SUCCESS );
}
static psa_status_t psa_tls12_prf_set_key( psa_tls12_prf_key_derivation_t *prf,
psa_algorithm_t hash_alg,
const uint8_t *data,
size_t data_length )
{
psa_status_t status;
if( prf->state != TLS12_PRF_STATE_SEED_SET )
return( PSA_ERROR_BAD_STATE );
status = psa_hmac_setup_internal( &prf->hmac, data, data_length, hash_alg );
if( status != PSA_SUCCESS )
return( status );
prf->state = TLS12_PRF_STATE_KEY_SET;
return( PSA_SUCCESS );
}
static psa_status_t psa_tls12_prf_psk_to_ms_set_key(
psa_tls12_prf_key_derivation_t *prf,
psa_algorithm_t hash_alg,
const uint8_t *data,
size_t data_length )
{
psa_status_t status;
uint8_t pms[ 4 + 2 * PSA_ALG_TLS12_PSK_TO_MS_MAX_PSK_LEN ];
uint8_t *cur = pms;
if( data_length > PSA_ALG_TLS12_PSK_TO_MS_MAX_PSK_LEN )
return( PSA_ERROR_INVALID_ARGUMENT );
/* Quoting RFC 4279, Section 2:
*
* The premaster secret is formed as follows: if the PSK is N octets
* long, concatenate a uint16 with the value N, N zero octets, a second
* uint16 with the value N, and the PSK itself.
*/
*cur++ = ( data_length >> 8 ) & 0xff;
*cur++ = ( data_length >> 0 ) & 0xff;
memset( cur, 0, data_length );
cur += data_length;
*cur++ = pms[0];
*cur++ = pms[1];
memcpy( cur, data, data_length );
cur += data_length;
status = psa_tls12_prf_set_key( prf, hash_alg, pms, cur - pms );
mbedtls_platform_zeroize( pms, sizeof( pms ) );
return( status );
}
static psa_status_t psa_tls12_prf_set_label( psa_tls12_prf_key_derivation_t *prf,
const uint8_t *data,
size_t data_length )
{
if( prf->state != TLS12_PRF_STATE_KEY_SET )
return( PSA_ERROR_BAD_STATE );
if( data_length != 0 )
{
prf->label = mbedtls_calloc( 1, data_length );
if( prf->label == NULL )
return( PSA_ERROR_INSUFFICIENT_MEMORY );
memcpy( prf->label, data, data_length );
prf->label_length = data_length;
}
prf->state = TLS12_PRF_STATE_LABEL_SET;
return( PSA_SUCCESS );
}
static psa_status_t psa_tls12_prf_input( psa_tls12_prf_key_derivation_t *prf,
psa_algorithm_t hash_alg,
psa_key_derivation_step_t step,
const uint8_t *data,
size_t data_length )
{
switch( step )
{
case PSA_KEY_DERIVATION_INPUT_SEED:
return( psa_tls12_prf_set_seed( prf, data, data_length ) );
case PSA_KEY_DERIVATION_INPUT_SECRET:
return( psa_tls12_prf_set_key( prf, hash_alg, data, data_length ) );
case PSA_KEY_DERIVATION_INPUT_LABEL:
return( psa_tls12_prf_set_label( prf, data, data_length ) );
default:
return( PSA_ERROR_INVALID_ARGUMENT );
}
}
static psa_status_t psa_tls12_prf_psk_to_ms_input(
psa_tls12_prf_key_derivation_t *prf,
psa_algorithm_t hash_alg,
psa_key_derivation_step_t step,
const uint8_t *data,
size_t data_length )
{
if( step == PSA_KEY_DERIVATION_INPUT_SECRET )
{
return( psa_tls12_prf_psk_to_ms_set_key( prf, hash_alg,
data, data_length ) );
}
return( psa_tls12_prf_input( prf, hash_alg, step, data, data_length ) );
}
#endif /* MBEDTLS_MD_C */
/** Check whether the given key type is acceptable for the given
* input step of a key derivation.
*
* Secret inputs must have the type #PSA_KEY_TYPE_DERIVE.
* Non-secret inputs must have the type #PSA_KEY_TYPE_RAW_DATA.
* Both secret and non-secret inputs can alternatively have the type
* #PSA_KEY_TYPE_NONE, which is never the type of a key object, meaning
* that the input was passed as a buffer rather than via a key object.
*/
static int psa_key_derivation_check_input_type(
psa_key_derivation_step_t step,
psa_key_type_t key_type )
{
switch( step )
{
case PSA_KEY_DERIVATION_INPUT_SECRET:
if( key_type == PSA_KEY_TYPE_DERIVE )
return( PSA_SUCCESS );
if( key_type == PSA_KEY_TYPE_NONE )
return( PSA_SUCCESS );
break;
case PSA_KEY_DERIVATION_INPUT_LABEL:
case PSA_KEY_DERIVATION_INPUT_SALT:
case PSA_KEY_DERIVATION_INPUT_INFO:
case PSA_KEY_DERIVATION_INPUT_SEED:
if( key_type == PSA_KEY_TYPE_RAW_DATA )
return( PSA_SUCCESS );
if( key_type == PSA_KEY_TYPE_NONE )
return( PSA_SUCCESS );
break;
}
return( PSA_ERROR_INVALID_ARGUMENT );
}
static psa_status_t psa_key_derivation_input_internal(
psa_key_derivation_operation_t *operation,
psa_key_derivation_step_t step,
psa_key_type_t key_type,
const uint8_t *data,
size_t data_length )
{
psa_status_t status;
psa_algorithm_t kdf_alg = psa_key_derivation_get_kdf_alg( operation );
status = psa_key_derivation_check_input_type( step, key_type );
if( status != PSA_SUCCESS )
goto exit;
#if defined(MBEDTLS_MD_C)
if( PSA_ALG_IS_HKDF( kdf_alg ) )
{
status = psa_hkdf_input( &operation->ctx.hkdf,
PSA_ALG_HKDF_GET_HASH( kdf_alg ),
step, data, data_length );
}
else if( PSA_ALG_IS_TLS12_PRF( kdf_alg ) )
{
status = psa_tls12_prf_input( &operation->ctx.tls12_prf,
PSA_ALG_HKDF_GET_HASH( kdf_alg ),
step, data, data_length );
}
else if( PSA_ALG_IS_TLS12_PSK_TO_MS( kdf_alg ) )
{
status = psa_tls12_prf_psk_to_ms_input( &operation->ctx.tls12_prf,
PSA_ALG_HKDF_GET_HASH( kdf_alg ),
step, data, data_length );
}
else
#endif /* MBEDTLS_MD_C */
{
/* This can't happen unless the operation object was not initialized */
return( PSA_ERROR_BAD_STATE );
}
exit:
if( status != PSA_SUCCESS )
psa_key_derivation_abort( operation );
return( status );
}
psa_status_t psa_key_derivation_input_bytes(
psa_key_derivation_operation_t *operation,
psa_key_derivation_step_t step,
const uint8_t *data,
size_t data_length )
{
return( psa_key_derivation_input_internal( operation, step,
PSA_KEY_TYPE_NONE,
data, data_length ) );
}
psa_status_t psa_key_derivation_input_key(
psa_key_derivation_operation_t *operation,
psa_key_derivation_step_t step,
psa_key_handle_t handle )
{
psa_key_slot_t *slot;
psa_status_t status;
status = psa_get_transparent_key( handle, &slot,
PSA_KEY_USAGE_DERIVE,
operation->alg );
if( status != PSA_SUCCESS )
{
psa_key_derivation_abort( operation );
return( status );
}
/* Passing a key object as a SECRET input unlocks the permission
* to output to a key object. */
if( step == PSA_KEY_DERIVATION_INPUT_SECRET )
operation->can_output_key = 1;
return( psa_key_derivation_input_internal( operation,
step, slot->attr.type,
slot->data.key.data,
slot->data.key.bytes ) );
}
/****************************************************************/
/* Key agreement */
/****************************************************************/
#if defined(MBEDTLS_ECDH_C)
static psa_status_t psa_key_agreement_ecdh( const uint8_t *peer_key,
size_t peer_key_length,
const mbedtls_ecp_keypair *our_key,
uint8_t *shared_secret,
size_t shared_secret_size,
size_t *shared_secret_length )
{
mbedtls_ecp_keypair *their_key = NULL;
mbedtls_ecdh_context ecdh;
psa_status_t status;
size_t bits = 0;
psa_ecc_family_t curve = mbedtls_ecc_group_to_psa( our_key->grp.id, &bits );
mbedtls_ecdh_init( &ecdh );
status = psa_load_ecp_representation( PSA_KEY_TYPE_ECC_PUBLIC_KEY(curve),
peer_key,
peer_key_length,
&their_key );
if( status != PSA_SUCCESS )
goto exit;
status = mbedtls_to_psa_error(
mbedtls_ecdh_get_params( &ecdh, their_key, MBEDTLS_ECDH_THEIRS ) );
if( status != PSA_SUCCESS )
goto exit;
status = mbedtls_to_psa_error(
mbedtls_ecdh_get_params( &ecdh, our_key, MBEDTLS_ECDH_OURS ) );
if( status != PSA_SUCCESS )
goto exit;
status = mbedtls_to_psa_error(
mbedtls_ecdh_calc_secret( &ecdh,
shared_secret_length,
shared_secret, shared_secret_size,
mbedtls_ctr_drbg_random,
&global_data.ctr_drbg ) );
if( status != PSA_SUCCESS )
goto exit;
if( PSA_BITS_TO_BYTES( bits ) != *shared_secret_length )
status = PSA_ERROR_CORRUPTION_DETECTED;
exit:
if( status != PSA_SUCCESS )
mbedtls_platform_zeroize( shared_secret, shared_secret_size );
mbedtls_ecdh_free( &ecdh );
mbedtls_ecp_keypair_free( their_key );
mbedtls_free( their_key );
return( status );
}
#endif /* MBEDTLS_ECDH_C */
#define PSA_KEY_AGREEMENT_MAX_SHARED_SECRET_SIZE MBEDTLS_ECP_MAX_BYTES
static psa_status_t psa_key_agreement_raw_internal( psa_algorithm_t alg,
psa_key_slot_t *private_key,
const uint8_t *peer_key,
size_t peer_key_length,
uint8_t *shared_secret,
size_t shared_secret_size,
size_t *shared_secret_length )
{
switch( alg )
{
#if defined(MBEDTLS_ECDH_C)
case PSA_ALG_ECDH:
if( ! PSA_KEY_TYPE_IS_ECC_KEY_PAIR( private_key->attr.type ) )
return( PSA_ERROR_INVALID_ARGUMENT );
mbedtls_ecp_keypair *ecp = NULL;
psa_status_t status = psa_load_ecp_representation(
private_key->attr.type,
private_key->data.key.data,
private_key->data.key.bytes,
&ecp );
if( status != PSA_SUCCESS )
return( status );
status = psa_key_agreement_ecdh( peer_key, peer_key_length,
ecp,
shared_secret, shared_secret_size,
shared_secret_length );
mbedtls_ecp_keypair_free( ecp );
mbedtls_free( ecp );
return( status );
#endif /* MBEDTLS_ECDH_C */
default:
(void) private_key;
(void) peer_key;
(void) peer_key_length;
(void) shared_secret;
(void) shared_secret_size;
(void) shared_secret_length;
return( PSA_ERROR_NOT_SUPPORTED );
}
}
/* Note that if this function fails, you must call psa_key_derivation_abort()
* to potentially free embedded data structures and wipe confidential data.
*/
static psa_status_t psa_key_agreement_internal( psa_key_derivation_operation_t *operation,
psa_key_derivation_step_t step,
psa_key_slot_t *private_key,
const uint8_t *peer_key,
size_t peer_key_length )
{
psa_status_t status;
uint8_t shared_secret[PSA_KEY_AGREEMENT_MAX_SHARED_SECRET_SIZE];
size_t shared_secret_length = 0;
psa_algorithm_t ka_alg = PSA_ALG_KEY_AGREEMENT_GET_BASE( operation->alg );
/* Step 1: run the secret agreement algorithm to generate the shared
* secret. */
status = psa_key_agreement_raw_internal( ka_alg,
private_key,
peer_key, peer_key_length,
shared_secret,
sizeof( shared_secret ),
&shared_secret_length );
if( status != PSA_SUCCESS )
goto exit;
/* Step 2: set up the key derivation to generate key material from
* the shared secret. A shared secret is permitted wherever a key
* of type DERIVE is permitted. */
status = psa_key_derivation_input_internal( operation, step,
PSA_KEY_TYPE_DERIVE,
shared_secret,
shared_secret_length );
exit:
mbedtls_platform_zeroize( shared_secret, shared_secret_length );
return( status );
}
psa_status_t psa_key_derivation_key_agreement( psa_key_derivation_operation_t *operation,
psa_key_derivation_step_t step,
psa_key_handle_t private_key,
const uint8_t *peer_key,
size_t peer_key_length )
{
psa_key_slot_t *slot;
psa_status_t status;
if( ! PSA_ALG_IS_KEY_AGREEMENT( operation->alg ) )
return( PSA_ERROR_INVALID_ARGUMENT );
status = psa_get_transparent_key( private_key, &slot,
PSA_KEY_USAGE_DERIVE, operation->alg );
if( status != PSA_SUCCESS )
return( status );
status = psa_key_agreement_internal( operation, step,
slot,
peer_key, peer_key_length );
if( status != PSA_SUCCESS )
psa_key_derivation_abort( operation );
else
{
/* If a private key has been added as SECRET, we allow the derived
* key material to be used as a key in PSA Crypto. */
if( step == PSA_KEY_DERIVATION_INPUT_SECRET )
operation->can_output_key = 1;
}
return( status );
}
psa_status_t psa_raw_key_agreement( psa_algorithm_t alg,
psa_key_handle_t private_key,
const uint8_t *peer_key,
size_t peer_key_length,
uint8_t *output,
size_t output_size,
size_t *output_length )
{
psa_key_slot_t *slot;
psa_status_t status;
if( ! PSA_ALG_IS_KEY_AGREEMENT( alg ) )
{
status = PSA_ERROR_INVALID_ARGUMENT;
goto exit;
}
status = psa_get_transparent_key( private_key, &slot,
PSA_KEY_USAGE_DERIVE, alg );
if( status != PSA_SUCCESS )
goto exit;
status = psa_key_agreement_raw_internal( alg, slot,
peer_key, peer_key_length,
output, output_size,
output_length );
exit:
if( status != PSA_SUCCESS )
{
/* If an error happens and is not handled properly, the output
* may be used as a key to protect sensitive data. Arrange for such
* a key to be random, which is likely to result in decryption or
* verification errors. This is better than filling the buffer with
* some constant data such as zeros, which would result in the data
* being protected with a reproducible, easily knowable key.
*/
psa_generate_random( output, output_size );
*output_length = output_size;
}
return( status );
}
/****************************************************************/
/* Random generation */
/****************************************************************/
psa_status_t psa_generate_random( uint8_t *output,
size_t output_size )
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
GUARD_MODULE_INITIALIZED;
while( output_size > MBEDTLS_CTR_DRBG_MAX_REQUEST )
{
ret = mbedtls_ctr_drbg_random( &global_data.ctr_drbg,
output,
MBEDTLS_CTR_DRBG_MAX_REQUEST );
if( ret != 0 )
return( mbedtls_to_psa_error( ret ) );
output += MBEDTLS_CTR_DRBG_MAX_REQUEST;
output_size -= MBEDTLS_CTR_DRBG_MAX_REQUEST;
}
ret = mbedtls_ctr_drbg_random( &global_data.ctr_drbg, output, output_size );
return( mbedtls_to_psa_error( ret ) );
}
#if defined(MBEDTLS_PSA_INJECT_ENTROPY)
#include "mbedtls/entropy_poll.h"
psa_status_t mbedtls_psa_inject_entropy( const uint8_t *seed,
size_t seed_size )
{
if( global_data.initialized )
return( PSA_ERROR_NOT_PERMITTED );
if( ( ( seed_size < MBEDTLS_ENTROPY_MIN_PLATFORM ) ||
( seed_size < MBEDTLS_ENTROPY_BLOCK_SIZE ) ) ||
( seed_size > MBEDTLS_ENTROPY_MAX_SEED_SIZE ) )
return( PSA_ERROR_INVALID_ARGUMENT );
return( mbedtls_psa_storage_inject_entropy( seed, seed_size ) );
}
#endif /* MBEDTLS_PSA_INJECT_ENTROPY */
#if defined(MBEDTLS_RSA_C) && defined(MBEDTLS_GENPRIME)
static psa_status_t psa_read_rsa_exponent( const uint8_t *domain_parameters,
size_t domain_parameters_size,
int *exponent )
{
size_t i;
uint32_t acc = 0;
if( domain_parameters_size == 0 )
{
*exponent = 65537;
return( PSA_SUCCESS );
}
/* Mbed TLS encodes the public exponent as an int. For simplicity, only
* support values that fit in a 32-bit integer, which is larger than
* int on just about every platform anyway. */
if( domain_parameters_size > sizeof( acc ) )
return( PSA_ERROR_NOT_SUPPORTED );
for( i = 0; i < domain_parameters_size; i++ )
acc = ( acc << 8 ) | domain_parameters[i];
if( acc > INT_MAX )
return( PSA_ERROR_NOT_SUPPORTED );
*exponent = acc;
return( PSA_SUCCESS );
}
#endif /* MBEDTLS_RSA_C && MBEDTLS_GENPRIME */
static psa_status_t psa_generate_key_internal(
psa_key_slot_t *slot, size_t bits,
const uint8_t *domain_parameters, size_t domain_parameters_size )
{
psa_key_type_t type = slot->attr.type;
if( domain_parameters == NULL && domain_parameters_size != 0 )
return( PSA_ERROR_INVALID_ARGUMENT );
if( key_type_is_raw_bytes( type ) )
{
psa_status_t status;
status = validate_unstructured_key_bit_size( slot->attr.type, bits );
if( status != PSA_SUCCESS )
return( status );
/* Allocate memory for the key */
status = psa_allocate_buffer_to_slot( slot, PSA_BITS_TO_BYTES( bits ) );
if( status != PSA_SUCCESS )
return( status );
status = psa_generate_random( slot->data.key.data,
slot->data.key.bytes );
if( status != PSA_SUCCESS )
return( status );
slot->attr.bits = (psa_key_bits_t) bits;
#if defined(MBEDTLS_DES_C)
if( type == PSA_KEY_TYPE_DES )
psa_des_set_key_parity( slot->data.key.data,
slot->data.key.bytes );
#endif /* MBEDTLS_DES_C */
}
else
#if defined(MBEDTLS_RSA_C) && defined(MBEDTLS_GENPRIME)
if ( type == PSA_KEY_TYPE_RSA_KEY_PAIR )
{
mbedtls_rsa_context rsa;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
int exponent;
psa_status_t status;
if( bits > PSA_VENDOR_RSA_MAX_KEY_BITS )
return( PSA_ERROR_NOT_SUPPORTED );
/* Accept only byte-aligned keys, for the same reasons as
* in psa_import_rsa_key(). */
if( bits % 8 != 0 )
return( PSA_ERROR_NOT_SUPPORTED );
status = psa_read_rsa_exponent( domain_parameters,
domain_parameters_size,
&exponent );
if( status != PSA_SUCCESS )
return( status );
mbedtls_rsa_init( &rsa, MBEDTLS_RSA_PKCS_V15, MBEDTLS_MD_NONE );
ret = mbedtls_rsa_gen_key( &rsa,
mbedtls_ctr_drbg_random,
&global_data.ctr_drbg,
(unsigned int) bits,
exponent );
if( ret != 0 )
return( mbedtls_to_psa_error( ret ) );
/* Make sure to always have an export representation available */
size_t bytes = PSA_KEY_EXPORT_RSA_KEY_PAIR_MAX_SIZE( bits );
status = psa_allocate_buffer_to_slot( slot, bytes );
if( status != PSA_SUCCESS )
{
mbedtls_rsa_free( &rsa );
return( status );
}
status = psa_export_rsa_key( type,
&rsa,
slot->data.key.data,
bytes,
&slot->data.key.bytes );
mbedtls_rsa_free( &rsa );
if( status != PSA_SUCCESS )
psa_remove_key_data_from_memory( slot );
return( status );
}
else
#endif /* MBEDTLS_RSA_C && MBEDTLS_GENPRIME */
#if defined(MBEDTLS_ECP_C)
if ( PSA_KEY_TYPE_IS_ECC( type ) && PSA_KEY_TYPE_IS_KEY_PAIR( type ) )
{
psa_ecc_family_t curve = PSA_KEY_TYPE_ECC_GET_FAMILY( type );
mbedtls_ecp_group_id grp_id =
mbedtls_ecc_group_of_psa( curve, PSA_BITS_TO_BYTES( bits ) );
const mbedtls_ecp_curve_info *curve_info =
mbedtls_ecp_curve_info_from_grp_id( grp_id );
mbedtls_ecp_keypair ecp;
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
if( domain_parameters_size != 0 )
return( PSA_ERROR_NOT_SUPPORTED );
if( grp_id == MBEDTLS_ECP_DP_NONE || curve_info == NULL )
return( PSA_ERROR_NOT_SUPPORTED );
mbedtls_ecp_keypair_init( &ecp );
ret = mbedtls_ecp_gen_key( grp_id, &ecp,
mbedtls_ctr_drbg_random,
&global_data.ctr_drbg );
if( ret != 0 )
{
mbedtls_ecp_keypair_free( &ecp );
return( mbedtls_to_psa_error( ret ) );
}
/* Make sure to always have an export representation available */
size_t bytes = PSA_BITS_TO_BYTES( bits );
psa_status_t status = psa_allocate_buffer_to_slot( slot, bytes );
if( status != PSA_SUCCESS )
{
mbedtls_ecp_keypair_free( &ecp );
return( status );
}
status = mbedtls_to_psa_error(
mbedtls_ecp_write_key( &ecp, slot->data.key.data, bytes ) );
mbedtls_ecp_keypair_free( &ecp );
if( status != PSA_SUCCESS ) {
memset( slot->data.key.data, 0, bytes );
psa_remove_key_data_from_memory( slot );
}
return( status );
}
else
#endif /* MBEDTLS_ECP_C */
{
return( PSA_ERROR_NOT_SUPPORTED );
}
return( PSA_SUCCESS );
}
psa_status_t psa_generate_key( const psa_key_attributes_t *attributes,
psa_key_handle_t *handle )
{
psa_status_t status;
psa_key_slot_t *slot = NULL;
psa_se_drv_table_entry_t *driver = NULL;
/* Reject any attempt to create a zero-length key so that we don't
* risk tripping up later, e.g. on a malloc(0) that returns NULL. */
if( psa_get_key_bits( attributes ) == 0 )
return( PSA_ERROR_INVALID_ARGUMENT );
status = psa_start_key_creation( PSA_KEY_CREATION_GENERATE,
attributes, handle, &slot, &driver );
if( status != PSA_SUCCESS )
goto exit;
status = psa_driver_wrapper_generate_key( attributes,
slot );
if( status != PSA_ERROR_NOT_SUPPORTED ||
psa_key_lifetime_is_external( attributes->core.lifetime ) )
goto exit;
status = psa_generate_key_internal(
slot, attributes->core.bits,
attributes->domain_parameters, attributes->domain_parameters_size );
exit:
if( status == PSA_SUCCESS )
status = psa_finish_key_creation( slot, driver );
if( status != PSA_SUCCESS )
{
psa_fail_key_creation( slot, driver );
*handle = 0;
}
return( status );
}
/****************************************************************/
/* Module setup */
/****************************************************************/
psa_status_t mbedtls_psa_crypto_configure_entropy_sources(
void (* entropy_init )( mbedtls_entropy_context *ctx ),
void (* entropy_free )( mbedtls_entropy_context *ctx ) )
{
if( global_data.rng_state != RNG_NOT_INITIALIZED )
return( PSA_ERROR_BAD_STATE );
global_data.entropy_init = entropy_init;
global_data.entropy_free = entropy_free;
return( PSA_SUCCESS );
}
void mbedtls_psa_crypto_free( void )
{
psa_wipe_all_key_slots( );
if( global_data.rng_state != RNG_NOT_INITIALIZED )
{
mbedtls_ctr_drbg_free( &global_data.ctr_drbg );
global_data.entropy_free( &global_data.entropy );
}
/* Wipe all remaining data, including configuration.
* In particular, this sets all state indicator to the value
* indicating "uninitialized". */
mbedtls_platform_zeroize( &global_data, sizeof( global_data ) );
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
/* Unregister all secure element drivers, so that we restart from
* a pristine state. */
psa_unregister_all_se_drivers( );
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
}
#if defined(PSA_CRYPTO_STORAGE_HAS_TRANSACTIONS)
/** Recover a transaction that was interrupted by a power failure.
*
* This function is called during initialization, before psa_crypto_init()
* returns. If this function returns a failure status, the initialization
* fails.
*/
static psa_status_t psa_crypto_recover_transaction(
const psa_crypto_transaction_t *transaction )
{
switch( transaction->unknown.type )
{
case PSA_CRYPTO_TRANSACTION_CREATE_KEY:
case PSA_CRYPTO_TRANSACTION_DESTROY_KEY:
/* TODO - fall through to the failure case until this
* is implemented.
* https://github.com/ARMmbed/mbed-crypto/issues/218
*/
default:
/* We found an unsupported transaction in the storage.
* We don't know what state the storage is in. Give up. */
return( PSA_ERROR_STORAGE_FAILURE );
}
}
#endif /* PSA_CRYPTO_STORAGE_HAS_TRANSACTIONS */
psa_status_t psa_crypto_init( void )
{
psa_status_t status;
const unsigned char drbg_seed[] = "PSA";
/* Double initialization is explicitly allowed. */
if( global_data.initialized != 0 )
return( PSA_SUCCESS );
/* Set default configuration if
* mbedtls_psa_crypto_configure_entropy_sources() hasn't been called. */
if( global_data.entropy_init == NULL )
global_data.entropy_init = mbedtls_entropy_init;
if( global_data.entropy_free == NULL )
global_data.entropy_free = mbedtls_entropy_free;
/* Initialize the random generator. */
global_data.entropy_init( &global_data.entropy );
#if defined(MBEDTLS_PSA_INJECT_ENTROPY) && \
defined(MBEDTLS_NO_DEFAULT_ENTROPY_SOURCES)
/* The PSA entropy injection feature depends on using NV seed as an entropy
* source. Add NV seed as an entropy source for PSA entropy injection. */
mbedtls_entropy_add_source( &global_data.entropy,
mbedtls_nv_seed_poll, NULL,
MBEDTLS_ENTROPY_BLOCK_SIZE,
MBEDTLS_ENTROPY_SOURCE_STRONG );
#endif
mbedtls_ctr_drbg_init( &global_data.ctr_drbg );
global_data.rng_state = RNG_INITIALIZED;
status = mbedtls_to_psa_error(
mbedtls_ctr_drbg_seed( &global_data.ctr_drbg,
mbedtls_entropy_func,
&global_data.entropy,
drbg_seed, sizeof( drbg_seed ) - 1 ) );
if( status != PSA_SUCCESS )
goto exit;
global_data.rng_state = RNG_SEEDED;
status = psa_initialize_key_slots( );
if( status != PSA_SUCCESS )
goto exit;
#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
status = psa_init_all_se_drivers( );
if( status != PSA_SUCCESS )
goto exit;
#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
#if defined(PSA_CRYPTO_STORAGE_HAS_TRANSACTIONS)
status = psa_crypto_load_transaction( );
if( status == PSA_SUCCESS )
{
status = psa_crypto_recover_transaction( &psa_crypto_transaction );
if( status != PSA_SUCCESS )
goto exit;
status = psa_crypto_stop_transaction( );
}
else if( status == PSA_ERROR_DOES_NOT_EXIST )
{
/* There's no transaction to complete. It's all good. */
status = PSA_SUCCESS;
}
#endif /* PSA_CRYPTO_STORAGE_HAS_TRANSACTIONS */
/* All done. */
global_data.initialized = 1;
exit:
if( status != PSA_SUCCESS )
mbedtls_psa_crypto_free( );
return( status );
}
#endif /* MBEDTLS_PSA_CRYPTO_C */
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