/* * PSA crypto layer on top of Mbed TLS crypto */ /* Copyright (C) 2018, ARM Limited, All Rights Reserved * 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. * * This file is part of mbed TLS (https://tls.mbed.org) */ #if !defined(MBEDTLS_CONFIG_FILE) #include "mbedtls/config.h" #else #include MBEDTLS_CONFIG_FILE #endif #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" #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 #include #include #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/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 ); static 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_BAD_STATE ); 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 ); 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) static psa_ecc_curve_t mbedtls_ecc_group_to_psa( mbedtls_ecp_group_id grpid ) { switch( grpid ) { case MBEDTLS_ECP_DP_SECP192R1: return( PSA_ECC_CURVE_SECP192R1 ); case MBEDTLS_ECP_DP_SECP224R1: return( PSA_ECC_CURVE_SECP224R1 ); case MBEDTLS_ECP_DP_SECP256R1: return( PSA_ECC_CURVE_SECP256R1 ); case MBEDTLS_ECP_DP_SECP384R1: return( PSA_ECC_CURVE_SECP384R1 ); case MBEDTLS_ECP_DP_SECP521R1: return( PSA_ECC_CURVE_SECP521R1 ); case MBEDTLS_ECP_DP_BP256R1: return( PSA_ECC_CURVE_BRAINPOOL_P256R1 ); case MBEDTLS_ECP_DP_BP384R1: return( PSA_ECC_CURVE_BRAINPOOL_P384R1 ); case MBEDTLS_ECP_DP_BP512R1: return( PSA_ECC_CURVE_BRAINPOOL_P512R1 ); case MBEDTLS_ECP_DP_CURVE25519: return( PSA_ECC_CURVE_CURVE25519 ); case MBEDTLS_ECP_DP_SECP192K1: return( PSA_ECC_CURVE_SECP192K1 ); case MBEDTLS_ECP_DP_SECP224K1: return( PSA_ECC_CURVE_SECP224K1 ); case MBEDTLS_ECP_DP_SECP256K1: return( PSA_ECC_CURVE_SECP256K1 ); case MBEDTLS_ECP_DP_CURVE448: return( PSA_ECC_CURVE_CURVE448 ); default: return( 0 ); } } static mbedtls_ecp_group_id mbedtls_ecc_group_of_psa( psa_ecc_curve_t curve ) { switch( curve ) { case PSA_ECC_CURVE_SECP192R1: return( MBEDTLS_ECP_DP_SECP192R1 ); case PSA_ECC_CURVE_SECP224R1: return( MBEDTLS_ECP_DP_SECP224R1 ); case PSA_ECC_CURVE_SECP256R1: return( MBEDTLS_ECP_DP_SECP256R1 ); case PSA_ECC_CURVE_SECP384R1: return( MBEDTLS_ECP_DP_SECP384R1 ); case PSA_ECC_CURVE_SECP521R1: return( MBEDTLS_ECP_DP_SECP521R1 ); case PSA_ECC_CURVE_BRAINPOOL_P256R1: return( MBEDTLS_ECP_DP_BP256R1 ); case PSA_ECC_CURVE_BRAINPOOL_P384R1: return( MBEDTLS_ECP_DP_BP384R1 ); case PSA_ECC_CURVE_BRAINPOOL_P512R1: return( MBEDTLS_ECP_DP_BP512R1 ); case PSA_ECC_CURVE_CURVE25519: return( MBEDTLS_ECP_DP_CURVE25519 ); case PSA_ECC_CURVE_SECP192K1: return( MBEDTLS_ECP_DP_SECP192K1 ); case PSA_ECC_CURVE_SECP224K1: return( MBEDTLS_ECP_DP_SECP224K1 ); case PSA_ECC_CURVE_SECP256K1: return( MBEDTLS_ECP_DP_SECP256K1 ); case PSA_ECC_CURVE_CURVE448: return( MBEDTLS_ECP_DP_CURVE448 ); default: return( MBEDTLS_ECP_DP_NONE ); } } #endif /* defined(MBEDTLS_ECP_C) */ static psa_status_t prepare_raw_data_slot( psa_key_type_t type, size_t bits, struct raw_data *raw ) { /* 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 ); /* Allocate memory for the key */ raw->bytes = PSA_BITS_TO_BYTES( bits ); raw->data = mbedtls_calloc( 1, raw->bytes ); if( raw->data == NULL ) { raw->bytes = 0; return( PSA_ERROR_INSUFFICIENT_MEMORY ); } return( PSA_SUCCESS ); } #if defined(MBEDTLS_RSA_C) && 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 ); } static psa_status_t psa_import_rsa_key( psa_key_type_t type, const uint8_t *data, size_t data_length, mbedtls_rsa_context **p_rsa ) { psa_status_t status; mbedtls_pk_context pk; mbedtls_rsa_context *rsa; size_t bits; mbedtls_pk_init( &pk ); /* Parse the data. */ if( PSA_KEY_TYPE_IS_KEY_PAIR( type ) ) status = mbedtls_to_psa_error( mbedtls_pk_parse_key( &pk, data, data_length, NULL, 0 ) ); else status = mbedtls_to_psa_error( mbedtls_pk_parse_public_key( &pk, 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( &pk ) != MBEDTLS_PK_RSA ) { status = PSA_ERROR_INVALID_ARGUMENT; goto exit; } rsa = mbedtls_pk_rsa( pk ); /* 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( rsa ) ); if( bits > PSA_VENDOR_RSA_MAX_KEY_BITS ) { status = PSA_ERROR_NOT_SUPPORTED; goto exit; } status = psa_check_rsa_key_byte_aligned( rsa ); exit: /* Free the content of the pk object only on error. */ if( status != PSA_SUCCESS ) { mbedtls_pk_free( &pk ); return( status ); } /* On success, store the content of the object in the RSA context. */ *p_rsa = rsa; return( PSA_SUCCESS ); } #endif /* defined(MBEDTLS_RSA_C) && defined(MBEDTLS_PK_PARSE_C) */ #if defined(MBEDTLS_ECP_C) /* Import a public key given as the uncompressed representation defined by SEC1 * 2.3.3 as the content of an ECPoint. */ static psa_status_t psa_import_ec_public_key( psa_ecc_curve_t curve, const uint8_t *data, size_t data_length, mbedtls_ecp_keypair **p_ecp ) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; mbedtls_ecp_keypair *ecp = NULL; mbedtls_ecp_group_id grp_id = mbedtls_ecc_group_of_psa( curve ); *p_ecp = NULL; ecp = mbedtls_calloc( 1, sizeof( *ecp ) ); if( ecp == NULL ) return( PSA_ERROR_INSUFFICIENT_MEMORY ); mbedtls_ecp_keypair_init( ecp ); /* Load the group. */ status = mbedtls_to_psa_error( mbedtls_ecp_group_load( &ecp->grp, grp_id ) ); if( status != PSA_SUCCESS ) goto exit; /* 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; *p_ecp = ecp; return( PSA_SUCCESS ); exit: if( ecp != NULL ) { mbedtls_ecp_keypair_free( ecp ); mbedtls_free( ecp ); } return( status ); } #endif /* defined(MBEDTLS_ECP_C) */ #if defined(MBEDTLS_ECP_C) /* Import a private key given as a byte string which is the private value * in big-endian order. */ static psa_status_t psa_import_ec_private_key( psa_ecc_curve_t curve, const uint8_t *data, size_t data_length, mbedtls_ecp_keypair **p_ecp ) { psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED; mbedtls_ecp_keypair *ecp = NULL; mbedtls_ecp_group_id grp_id = mbedtls_ecc_group_of_psa( curve ); if( PSA_BITS_TO_BYTES( PSA_ECC_CURVE_BITS( curve ) ) != data_length ) return( PSA_ERROR_INVALID_ARGUMENT ); *p_ecp = NULL; ecp = mbedtls_calloc( 1, sizeof( mbedtls_ecp_keypair ) ); if( ecp == NULL ) return( PSA_ERROR_INSUFFICIENT_MEMORY ); mbedtls_ecp_keypair_init( ecp ); /* Load the group. */ status = mbedtls_to_psa_error( mbedtls_ecp_group_load( &ecp->grp, grp_id ) ); if( status != PSA_SUCCESS ) goto exit; /* Load the secret value. */ status = mbedtls_to_psa_error( mbedtls_mpi_read_binary( &ecp->d, data, data_length ) ); if( status != PSA_SUCCESS ) goto exit; /* Validate the private key. */ status = mbedtls_to_psa_error( mbedtls_ecp_check_privkey( &ecp->grp, &ecp->d ) ); if( status != PSA_SUCCESS ) goto exit; /* Calculate the public key from the private 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 ) goto exit; *p_ecp = ecp; return( PSA_SUCCESS ); exit: if( ecp != NULL ) { mbedtls_ecp_keypair_free( ecp ); mbedtls_free( ecp ); } return( status ); } #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 ); } /** Calculate the size of the key in the given slot, in bits. * * \param[in] slot A key slot containing a transparent key. * * \return The key size in bits, calculated from the key data. */ static psa_key_bits_t psa_calculate_key_bits( const psa_key_slot_t *slot ) { size_t bits = 0; /* return 0 on an empty slot */ if( key_type_is_raw_bytes( slot->attr.type ) ) bits = PSA_BYTES_TO_BITS( slot->data.raw.bytes ); #if defined(MBEDTLS_RSA_C) else if( PSA_KEY_TYPE_IS_RSA( slot->attr.type ) ) bits = PSA_BYTES_TO_BITS( mbedtls_rsa_get_len( slot->data.rsa ) ); #endif /* defined(MBEDTLS_RSA_C) */ #if defined(MBEDTLS_ECP_C) else if( PSA_KEY_TYPE_IS_ECC( slot->attr.type ) ) bits = slot->data.ecp->grp.pbits; #endif /* defined(MBEDTLS_ECP_C) */ /* We know that the size fits in psa_key_bits_t thanks to checks * when the key was created. */ return( (psa_key_bits_t) bits ); } /** 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; if( key_type_is_raw_bytes( slot->attr.type ) ) { size_t bit_size = PSA_BYTES_TO_BITS( data_length ); /* Ensure that the bytes-to-bit conversion didn't overflow. */ 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 = prepare_raw_data_slot( slot->attr.type, bit_size, &slot->data.raw ); if( status != PSA_SUCCESS ) return( status ); if( data_length != 0 ) memcpy( slot->data.raw.data, data, data_length ); } else #if defined(MBEDTLS_ECP_C) if( PSA_KEY_TYPE_IS_ECC_KEY_PAIR( slot->attr.type ) ) { status = psa_import_ec_private_key( PSA_KEY_TYPE_GET_CURVE( slot->attr.type ), data, data_length, &slot->data.ecp ); } else if( PSA_KEY_TYPE_IS_ECC_PUBLIC_KEY( slot->attr.type ) ) { status = psa_import_ec_public_key( PSA_KEY_TYPE_GET_CURVE( slot->attr.type ), data, data_length, &slot->data.ecp ); } else #endif /* MBEDTLS_ECP_C */ #if defined(MBEDTLS_RSA_C) && defined(MBEDTLS_PK_PARSE_C) if( PSA_KEY_TYPE_IS_RSA( slot->attr.type ) ) { status = psa_import_rsa_key( slot->attr.type, data, data_length, &slot->data.rsa ); } else #endif /* defined(MBEDTLS_RSA_C) && defined(MBEDTLS_PK_PARSE_C) */ { return( PSA_ERROR_NOT_SUPPORTED ); } if( status == PSA_SUCCESS ) { /* 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_calculate_key_bits( slot ); } 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 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 */ if( slot->attr.type == PSA_KEY_TYPE_NONE ) { /* No key material to clean. */ } else if( key_type_is_raw_bytes( slot->attr.type ) ) { mbedtls_free( slot->data.raw.data ); } else #if defined(MBEDTLS_RSA_C) if( PSA_KEY_TYPE_IS_RSA( slot->attr.type ) ) { mbedtls_rsa_free( slot->data.rsa ); mbedtls_free( slot->data.rsa ); } else #endif /* defined(MBEDTLS_RSA_C) */ #if defined(MBEDTLS_ECP_C) if( PSA_KEY_TYPE_IS_ECC( slot->attr.type ) ) { mbedtls_ecp_keypair_free( slot->data.ecp ); mbedtls_free( slot->data.ecp ); } else #endif /* defined(MBEDTLS_ECP_C) */ { /* Shouldn't happen: the key type is not any type that we * put in. */ return( PSA_ERROR_CORRUPTION_DETECTED ); } 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 */ 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; 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 */ status = psa_get_rsa_public_exponent( slot->data.rsa, attributes ); 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 */ #if defined(MBEDTLS_RSA_C) || defined(MBEDTLS_ECP_C) static int pk_write_pubkey_simple( mbedtls_pk_context *key, unsigned char *buf, size_t size ) { int ret; unsigned char *c; size_t len = 0; c = buf + size; MBEDTLS_ASN1_CHK_ADD( len, mbedtls_pk_write_pubkey( &c, buf, key ) ); return( (int) len ); } #endif /* defined(MBEDTLS_RSA_C) || defined(MBEDTLS_ECP_C) */ 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 ) ) { if( slot->data.raw.bytes > data_size ) return( PSA_ERROR_BUFFER_TOO_SMALL ); memcpy( data, slot->data.raw.data, slot->data.raw.bytes ); memset( data + slot->data.raw.bytes, 0, data_size - slot->data.raw.bytes ); *data_length = slot->data.raw.bytes; return( PSA_SUCCESS ); } #if defined(MBEDTLS_ECP_C) if( PSA_KEY_TYPE_IS_ECC_KEY_PAIR( slot->attr.type ) && !export_public_key ) { psa_status_t status; size_t bytes = PSA_BITS_TO_BYTES( slot->attr.bits ); if( bytes > data_size ) return( PSA_ERROR_BUFFER_TOO_SMALL ); status = mbedtls_to_psa_error( mbedtls_mpi_write_binary( &slot->data.ecp->d, data, bytes ) ); if( status != PSA_SUCCESS ) return( status ); memset( data + bytes, 0, data_size - bytes ); *data_length = bytes; return( PSA_SUCCESS ); } #endif else { #if defined(MBEDTLS_PK_WRITE_C) if( PSA_KEY_TYPE_IS_RSA( slot->attr.type ) || PSA_KEY_TYPE_IS_ECC( slot->attr.type ) ) { mbedtls_pk_context pk; int ret; if( PSA_KEY_TYPE_IS_RSA( slot->attr.type ) ) { #if defined(MBEDTLS_RSA_C) mbedtls_pk_init( &pk ); pk.pk_info = &mbedtls_rsa_info; pk.pk_ctx = slot->data.rsa; #else return( PSA_ERROR_NOT_SUPPORTED ); #endif } else { #if defined(MBEDTLS_ECP_C) mbedtls_pk_init( &pk ); pk.pk_info = &mbedtls_eckey_info; pk.pk_ctx = slot->data.ecp; #else return( PSA_ERROR_NOT_SUPPORTED ); #endif } if( export_public_key || PSA_KEY_TYPE_IS_PUBLIC_KEY( slot->attr.type ) ) { ret = pk_write_pubkey_simple( &pk, data, data_size ); } else { ret = mbedtls_pk_write_key_der( &pk, data, data_size ); } if( ret < 0 ) { 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 #endif /* defined(MBEDTLS_PK_WRITE_C) */ { /* 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 | PSA_KEY_USAGE_VERIFY | 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; if( attributes->core.lifetime != PSA_KEY_LIFETIME_VOLATILE ) { status = psa_validate_persistent_key_parameters( attributes->core.lifetime, attributes->core.id, p_drv, 1 ); 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 a key (but not when registering an existing key): * create the key file in internal storage, create the * key inside the secure element, and update the driver's * persistent data. Start a transaction that will encompass these * three actions. */ /* 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 && method != PSA_KEY_CREATION_REGISTER ) { status = psa_find_se_slot_for_key( attributes, method, *p_drv, &slot->data.se.slot_number ); if( status != PSA_SUCCESS ) return( status ); 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 ); } } #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( slot->attr.lifetime != PSA_KEY_LIFETIME_VOLATILE ) { #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" ); static_assert( sizeof( slot->attr.bits ) == sizeof( data.bits ), "Bit-size 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 ) ); memcpy( &data.bits, &slot->attr.bits, sizeof( slot->attr.bits ) ); 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 key in a secure element requires a transaction, * but registration 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_mpi actual, required; int ret; mbedtls_mpi_init( &actual ); mbedtls_mpi_init( &required ); ret = mbedtls_rsa_export( slot->data.rsa, NULL, NULL, NULL, NULL, &actual ); 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; const psa_drv_se_t *drv; 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; if( driver == NULL ) { status = PSA_ERROR_INVALID_ARGUMENT; goto exit; } drv = psa_get_se_driver_methods( driver ); if ( psa_get_key_slot_number( attributes, &slot->data.se.slot_number ) != PSA_SUCCESS ) { /* The application didn't specify a slot number. This doesn't * make sense when registering a slot. */ status = PSA_ERROR_INVALID_ARGUMENT; goto exit; } /* If the driver has a slot number validation method, call it. * If it doesn't, it means the secure element is unable to validate * anything and so we have to trust the application. */ if( drv->key_management != NULL && drv->key_management->p_validate_slot_number != NULL ) { status = drv->key_management->p_validate_slot_number( psa_get_se_driver_context( driver ), attributes, PSA_KEY_CREATION_REGISTER, slot->data.se.slot_number ); 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 */ /****************************************************************/ 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) case PSA_ALG_SHA_384: return( &mbedtls_sha384_info ); case PSA_ALG_SHA_512: return( &mbedtls_sha512_info ); #endif default: return( NULL ); } } 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) case PSA_ALG_SHA_384: 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; /* 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) case PSA_ALG_SHA_384: mbedtls_sha512_init( &operation->ctx.sha512 ); ret = mbedtls_sha512_starts_ret( &operation->ctx.sha512, 1 ); break; 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; /* 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) case PSA_ALG_SHA_384: 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; 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) case PSA_ALG_SHA_384: 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_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) case PSA_ALG_SHA_384: 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_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; 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.raw.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_setup( &hmac->hash_ctx, hash_alg ); if( status != PSA_SUCCESS ) goto cleanup; status = psa_hash_update( &hmac->hash_ctx, key, key_length ); if( status != PSA_SUCCESS ) goto cleanup; status = psa_hash_finish( &hmac->hash_ctx, 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 : PSA_KEY_USAGE_VERIFY; 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; 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.raw.data, slot->data.raw.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( 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_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_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_ECDSA_C) /* `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_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_ECDSA_DETERMINISTIC) 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 /* MBEDTLS_ECDSA_DETERMINISTIC */ { (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_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 ) ); 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 /* MBEDTLS_ECDSA_C */ psa_status_t psa_asymmetric_sign( 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; #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 */ *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, alg ); if( status != PSA_SUCCESS ) goto exit; if( ! PSA_KEY_TYPE_IS_KEY_PAIR( slot->attr.type ) ) { status = PSA_ERROR_INVALID_ARGUMENT; goto exit; } #if defined(MBEDTLS_PSA_CRYPTO_SE_C) if( psa_get_se_driver( slot->attr.lifetime, &drv, &drv_context ) ) { if( drv->asymmetric == NULL || drv->asymmetric->p_sign == NULL ) { status = PSA_ERROR_NOT_SUPPORTED; goto exit; } status = drv->asymmetric->p_sign( drv_context, slot->data.se.slot_number, alg, hash, hash_length, signature, signature_size, signature_length ); } else #endif /* MBEDTLS_PSA_CRYPTO_SE_C */ #if defined(MBEDTLS_RSA_C) if( slot->attr.type == PSA_KEY_TYPE_RSA_KEY_PAIR ) { status = psa_rsa_sign( slot->data.rsa, alg, hash, hash_length, signature, signature_size, signature_length ); } else #endif /* defined(MBEDTLS_RSA_C) */ #if defined(MBEDTLS_ECP_C) if( PSA_KEY_TYPE_IS_ECC( slot->attr.type ) ) { #if defined(MBEDTLS_ECDSA_C) if( #if defined(MBEDTLS_ECDSA_DETERMINISTIC) PSA_ALG_IS_ECDSA( alg ) #else PSA_ALG_IS_RANDOMIZED_ECDSA( alg ) #endif ) status = psa_ecdsa_sign( slot->data.ecp, alg, hash, hash_length, signature, signature_size, signature_length ); else #endif /* defined(MBEDTLS_ECDSA_C) */ { 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_asymmetric_verify( 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; #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 */ status = psa_get_key_from_slot( handle, &slot, PSA_KEY_USAGE_VERIFY, alg ); if( status != PSA_SUCCESS ) return( status ); #if defined(MBEDTLS_PSA_CRYPTO_SE_C) if( psa_get_se_driver( slot->attr.lifetime, &drv, &drv_context ) ) { if( drv->asymmetric == NULL || drv->asymmetric->p_verify == NULL ) return( PSA_ERROR_NOT_SUPPORTED ); return( drv->asymmetric->p_verify( drv_context, slot->data.se.slot_number, alg, hash, hash_length, signature, signature_length ) ); } else #endif /* MBEDTLS_PSA_CRYPTO_SE_C */ #if defined(MBEDTLS_RSA_C) if( PSA_KEY_TYPE_IS_RSA( slot->attr.type ) ) { return( psa_rsa_verify( slot->data.rsa, alg, hash, hash_length, signature, signature_length ) ); } else #endif /* defined(MBEDTLS_RSA_C) */ #if defined(MBEDTLS_ECP_C) if( PSA_KEY_TYPE_IS_ECC( slot->attr.type ) ) { #if defined(MBEDTLS_ECDSA_C) if( PSA_ALG_IS_ECDSA( alg ) ) return( psa_ecdsa_verify( slot->data.ecp, hash, hash_length, signature, signature_length ) ); else #endif /* defined(MBEDTLS_ECDSA_C) */ { 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 = slot->data.rsa; int ret; if( output_size < mbedtls_rsa_get_len( rsa ) ) return( PSA_ERROR_BUFFER_TOO_SMALL ); #if defined(MBEDTLS_PKCS1_V15) if( alg == PSA_ALG_RSA_PKCS1V15_CRYPT ) { ret = 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 ); ret = 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 */ { return( PSA_ERROR_INVALID_ARGUMENT ); } if( ret == 0 ) *output_length = mbedtls_rsa_get_len( rsa ); return( mbedtls_to_psa_error( ret ) ); } 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 = slot->data.rsa; int ret; if( input_length != mbedtls_rsa_get_len( rsa ) ) return( PSA_ERROR_INVALID_ARGUMENT ); #if defined(MBEDTLS_PKCS1_V15) if( alg == PSA_ALG_RSA_PKCS1V15_CRYPT ) { ret = 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 ); ret = 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 */ { return( PSA_ERROR_INVALID_ARGUMENT ); } return( mbedtls_to_psa_error( ret ) ); } else #endif /* defined(MBEDTLS_RSA_C) */ { return( PSA_ERROR_NOT_SUPPORTED ); } } /****************************************************************/ /* Symmetric cryptography */ /****************************************************************/ /* Initialize the cipher operation structure. Once this function has been * called, psa_cipher_abort can run and will do the right thing. */ static psa_status_t psa_cipher_init( psa_cipher_operation_t *operation, psa_algorithm_t alg ) { if( ! PSA_ALG_IS_CIPHER( alg ) ) { memset( operation, 0, sizeof( *operation ) ); return( PSA_ERROR_INVALID_ARGUMENT ); } operation->alg = alg; operation->key_set = 0; operation->iv_set = 0; operation->iv_required = 1; operation->iv_size = 0; operation->block_size = 0; mbedtls_cipher_init( &operation->ctx.cipher ); return( PSA_SUCCESS ); } 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 ); } status = psa_cipher_init( operation, alg ); if( status != PSA_SUCCESS ) return( status ); status = psa_get_transparent_key( handle, &slot, usage, alg); if( status != PSA_SUCCESS ) goto exit; 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.raw.data, 16 ); memcpy( keys + 16, slot->data.raw.data, 8 ); ret = mbedtls_cipher_setkey( &operation->ctx.cipher, keys, 192, cipher_operation ); } else #endif { ret = mbedtls_cipher_setkey( &operation->ctx.cipher, slot->data.raw.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->key_set = 1; 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 ) { 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 exit: if( status == 0 ) status = mbedtls_to_psa_error( ret ); if( status != 0 ) 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; if( operation->iv_set || ! operation->iv_required ) { return( PSA_ERROR_BAD_STATE ); } 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 ) 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; if( operation->iv_set || ! operation->iv_required ) { return( PSA_ERROR_BAD_STATE ); } 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 ); } 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; int ret; size_t expected_output_size; if( operation->alg == 0 ) { return( PSA_ERROR_BAD_STATE ); } 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; } ret = mbedtls_cipher_update( &operation->ctx.cipher, input, input_length, output, output_length ); status = mbedtls_to_psa_error( ret ); 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; int cipher_ret = MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE; uint8_t temp_output_buffer[MBEDTLS_MAX_BLOCK_LENGTH]; if( ! operation->key_set ) { return( PSA_ERROR_BAD_STATE ); } if( operation->iv_required && ! operation->iv_set ) { return( PSA_ERROR_BAD_STATE ); } if( operation->ctx.cipher.operation == MBEDTLS_ENCRYPT && operation->alg == PSA_ALG_CBC_NO_PADDING && operation->ctx.cipher.unprocessed_len != 0 ) { status = PSA_ERROR_INVALID_ARGUMENT; goto error; } cipher_ret = mbedtls_cipher_finish( &operation->ctx.cipher, temp_output_buffer, output_length ); if( cipher_ret != 0 ) { status = mbedtls_to_psa_error( cipher_ret ); goto error; } 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; goto error; } mbedtls_platform_zeroize( temp_output_buffer, sizeof( temp_output_buffer ) ); status = psa_cipher_abort( operation ); return( status ); error: *output_length = 0; mbedtls_platform_zeroize( temp_output_buffer, sizeof( temp_output_buffer ) ); (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 * 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 ); mbedtls_cipher_free( &operation->ctx.cipher ); operation->alg = 0; operation->key_set = 0; operation->iv_set = 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.raw.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.raw.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.raw.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_(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 ); 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 */ static psa_status_t psa_key_derivation_input_internal( psa_key_derivation_operation_t *operation, psa_key_derivation_step_t step, const uint8_t *data, size_t data_length ) { psa_status_t status; psa_algorithm_t kdf_alg = psa_key_derivation_get_kdf_alg( operation ); #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 ); } 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 ) { if( step == PSA_KEY_DERIVATION_INPUT_SECRET ) return( PSA_ERROR_INVALID_ARGUMENT ); return( psa_key_derivation_input_internal( operation, step, 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 ) return( status ); if( slot->attr.type != PSA_KEY_TYPE_DERIVE ) return( PSA_ERROR_INVALID_ARGUMENT ); /* Don't allow a key to be used as an input that is usually public. * This is debatable. It's ok from a cryptographic perspective to * use secret material as an input that is usually public. However * the material should be dedicated to a particular input step, * otherwise this may allow the key to be used in an unintended way * and leak values derived from the key. So be conservative. */ if( step != PSA_KEY_DERIVATION_INPUT_SECRET ) return( PSA_ERROR_INVALID_ARGUMENT ); return( psa_key_derivation_input_internal( operation, step, slot->data.raw.data, slot->data.raw.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; mbedtls_ecdh_init( &ecdh ); status = psa_import_ec_public_key( mbedtls_ecc_group_to_psa( our_key->grp.id ), 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 ) ); exit: 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 ); return( psa_key_agreement_ecdh( peer_key, peer_key_length, private_key->data.ecp, shared_secret, shared_secret_size, shared_secret_length ) ); #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. */ status = psa_key_derivation_input_internal( operation, step, 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 ); 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; 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 = prepare_raw_data_slot( type, bits, &slot->data.raw ); if( status != PSA_SUCCESS ) return( status ); status = psa_generate_random( slot->data.raw.data, slot->data.raw.bytes ); if( status != PSA_SUCCESS ) return( status ); #if defined(MBEDTLS_DES_C) if( type == PSA_KEY_TYPE_DES ) psa_des_set_key_parity( slot->data.raw.data, slot->data.raw.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; 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 ); rsa = mbedtls_calloc( 1, sizeof( *rsa ) ); if( rsa == NULL ) return( PSA_ERROR_INSUFFICIENT_MEMORY ); 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 ) { mbedtls_rsa_free( rsa ); mbedtls_free( rsa ); return( mbedtls_to_psa_error( ret ) ); } slot->data.rsa = rsa; } 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_curve_t curve = PSA_KEY_TYPE_GET_CURVE( type ); mbedtls_ecp_group_id grp_id = mbedtls_ecc_group_of_psa( curve ); const mbedtls_ecp_curve_info *curve_info = mbedtls_ecp_curve_info_from_grp_id( grp_id ); mbedtls_ecp_keypair *ecp; int ret; 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 ); if( curve_info->bit_size != bits ) return( PSA_ERROR_INVALID_ARGUMENT ); ecp = mbedtls_calloc( 1, sizeof( *ecp ) ); if( ecp == NULL ) return( PSA_ERROR_INSUFFICIENT_MEMORY ); 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 ); mbedtls_free( ecp ); return( mbedtls_to_psa_error( ret ) ); } slot->data.ecp = ecp; } 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; #if defined(MBEDTLS_PSA_CRYPTO_SE_C) if( driver != NULL ) { const psa_drv_se_t *drv = psa_get_se_driver_methods( driver ); size_t pubkey_length = 0; /* We don't support this feature yet */ if( drv->key_management == NULL || drv->key_management->p_generate == NULL ) { status = PSA_ERROR_NOT_SUPPORTED; goto exit; } status = drv->key_management->p_generate( psa_get_se_driver_context( driver ), slot->data.se.slot_number, attributes, NULL, 0, &pubkey_length ); } else #endif /* MBEDTLS_PSA_CRYPTO_SE_C */ { 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(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 */