mirror of
https://github.com/yuzu-emu/mbedtls.git
synced 2024-11-24 02:55:38 +01:00
528 lines
22 KiB
C
528 lines
22 KiB
C
/**
|
|
* \file psa/crypto_sizes.h
|
|
*
|
|
* \brief PSA cryptography module: Mbed TLS buffer size macros
|
|
*
|
|
* \note This file may not be included directly. Applications must
|
|
* include psa/crypto.h.
|
|
*
|
|
* This file contains the definitions of macros that are useful to
|
|
* compute buffer sizes. The signatures and semantics of these macros
|
|
* are standardized, but the definitions are not, because they depend on
|
|
* the available algorithms and, in some cases, on permitted tolerances
|
|
* on buffer sizes.
|
|
*
|
|
* In implementations with isolation between the application and the
|
|
* cryptography module, implementers should take care to ensure that
|
|
* the definitions that are exposed to applications match what the
|
|
* module implements.
|
|
*
|
|
* Macros that compute sizes whose values do not depend on the
|
|
* implementation are in crypto.h.
|
|
*/
|
|
/*
|
|
* 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)
|
|
*/
|
|
|
|
#ifndef PSA_CRYPTO_SIZES_H
|
|
#define PSA_CRYPTO_SIZES_H
|
|
|
|
/* Include the Mbed TLS configuration file, the way Mbed TLS does it
|
|
* in each of its header files. */
|
|
#if !defined(MBEDTLS_CONFIG_FILE)
|
|
#include "../mbedtls/config.h"
|
|
#else
|
|
#include MBEDTLS_CONFIG_FILE
|
|
#endif
|
|
|
|
/** \def PSA_HASH_MAX_SIZE
|
|
*
|
|
* Maximum size of a hash.
|
|
*
|
|
* This macro must expand to a compile-time constant integer. This value
|
|
* should be the maximum size of a hash supported by the implementation,
|
|
* in bytes, and must be no smaller than this maximum.
|
|
*/
|
|
/* Note: for HMAC-SHA-3, the block size is 144 bytes for HMAC-SHA3-226,
|
|
* 136 bytes for HMAC-SHA3-256, 104 bytes for SHA3-384, 72 bytes for
|
|
* HMAC-SHA3-512. */
|
|
#if defined(MBEDTLS_SHA512_C)
|
|
#define PSA_HASH_MAX_SIZE 64
|
|
#define PSA_HMAC_MAX_HASH_BLOCK_SIZE 128
|
|
#else
|
|
#define PSA_HASH_MAX_SIZE 32
|
|
#define PSA_HMAC_MAX_HASH_BLOCK_SIZE 64
|
|
#endif
|
|
|
|
/** \def PSA_MAC_MAX_SIZE
|
|
*
|
|
* Maximum size of a MAC.
|
|
*
|
|
* This macro must expand to a compile-time constant integer. This value
|
|
* should be the maximum size of a MAC supported by the implementation,
|
|
* in bytes, and must be no smaller than this maximum.
|
|
*/
|
|
/* All non-HMAC MACs have a maximum size that's smaller than the
|
|
* minimum possible value of PSA_HASH_MAX_SIZE in this implementation. */
|
|
/* Note that the encoding of truncated MAC algorithms limits this value
|
|
* to 64 bytes.
|
|
*/
|
|
#define PSA_MAC_MAX_SIZE PSA_HASH_MAX_SIZE
|
|
|
|
/* The maximum size of an RSA key on this implementation, in bits.
|
|
* This is a vendor-specific macro.
|
|
*
|
|
* Mbed TLS does not set a hard limit on the size of RSA keys: any key
|
|
* whose parameters fit in a bignum is accepted. However large keys can
|
|
* induce a large memory usage and long computation times. Unlike other
|
|
* auxiliary macros in this file and in crypto.h, which reflect how the
|
|
* library is configured, this macro defines how the library is
|
|
* configured. This implementation refuses to import or generate an
|
|
* RSA key whose size is larger than the value defined here.
|
|
*
|
|
* Note that an implementation may set different size limits for different
|
|
* operations, and does not need to accept all key sizes up to the limit. */
|
|
#define PSA_VENDOR_RSA_MAX_KEY_BITS 4096
|
|
|
|
/* The maximum size of an ECC key on this implementation, in bits.
|
|
* This is a vendor-specific macro. */
|
|
#if defined(MBEDTLS_ECP_DP_SECP521R1_ENABLED)
|
|
#define PSA_VENDOR_ECC_MAX_CURVE_BITS 521
|
|
#elif defined(MBEDTLS_ECP_DP_BP512R1_ENABLED)
|
|
#define PSA_VENDOR_ECC_MAX_CURVE_BITS 512
|
|
#elif defined(MBEDTLS_ECP_DP_CURVE448_ENABLED)
|
|
#define PSA_VENDOR_ECC_MAX_CURVE_BITS 448
|
|
#elif defined(MBEDTLS_ECP_DP_SECP384R1_ENABLED)
|
|
#define PSA_VENDOR_ECC_MAX_CURVE_BITS 384
|
|
#elif defined(MBEDTLS_ECP_DP_BP384R1_ENABLED)
|
|
#define PSA_VENDOR_ECC_MAX_CURVE_BITS 384
|
|
#elif defined(MBEDTLS_ECP_DP_SECP256R1_ENABLED)
|
|
#define PSA_VENDOR_ECC_MAX_CURVE_BITS 256
|
|
#elif defined(MBEDTLS_ECP_DP_SECP256K1_ENABLED)
|
|
#define PSA_VENDOR_ECC_MAX_CURVE_BITS 256
|
|
#elif defined(MBEDTLS_ECP_DP_BP256R1_ENABLED)
|
|
#define PSA_VENDOR_ECC_MAX_CURVE_BITS 256
|
|
#elif defined(MBEDTLS_ECP_DP_CURVE25519_ENABLED)
|
|
#define PSA_VENDOR_ECC_MAX_CURVE_BITS 255
|
|
#elif defined(MBEDTLS_ECP_DP_SECP224R1_ENABLED)
|
|
#define PSA_VENDOR_ECC_MAX_CURVE_BITS 224
|
|
#elif defined(MBEDTLS_ECP_DP_SECP224K1_ENABLED)
|
|
#define PSA_VENDOR_ECC_MAX_CURVE_BITS 224
|
|
#elif defined(MBEDTLS_ECP_DP_SECP192R1_ENABLED)
|
|
#define PSA_VENDOR_ECC_MAX_CURVE_BITS 192
|
|
#elif defined(MBEDTLS_ECP_DP_SECP192K1_ENABLED)
|
|
#define PSA_VENDOR_ECC_MAX_CURVE_BITS 192
|
|
#else
|
|
#define PSA_VENDOR_ECC_MAX_CURVE_BITS 0
|
|
#endif
|
|
|
|
/** \def PSA_ALG_TLS12_PSK_TO_MS_MAX_PSK_LEN
|
|
*
|
|
* This macro returns the maximum length of the PSK supported
|
|
* by the TLS-1.2 PSK-to-MS key derivation.
|
|
*
|
|
* Quoting RFC 4279, Sect 5.3:
|
|
* TLS implementations supporting these ciphersuites MUST support
|
|
* arbitrary PSK identities up to 128 octets in length, and arbitrary
|
|
* PSKs up to 64 octets in length. Supporting longer identities and
|
|
* keys is RECOMMENDED.
|
|
*
|
|
* Therefore, no implementation should define a value smaller than 64
|
|
* for #PSA_ALG_TLS12_PSK_TO_MS_MAX_PSK_LEN.
|
|
*/
|
|
#define PSA_ALG_TLS12_PSK_TO_MS_MAX_PSK_LEN 128
|
|
|
|
/** \def PSA_ASYMMETRIC_SIGNATURE_MAX_SIZE
|
|
*
|
|
* Maximum size of an asymmetric signature.
|
|
*
|
|
* This macro must expand to a compile-time constant integer. This value
|
|
* should be the maximum size of a MAC supported by the implementation,
|
|
* in bytes, and must be no smaller than this maximum.
|
|
*/
|
|
#define PSA_ASYMMETRIC_SIGNATURE_MAX_SIZE \
|
|
PSA_BITS_TO_BYTES( \
|
|
PSA_VENDOR_RSA_MAX_KEY_BITS > PSA_VENDOR_ECC_MAX_CURVE_BITS ? \
|
|
PSA_VENDOR_RSA_MAX_KEY_BITS : \
|
|
PSA_VENDOR_ECC_MAX_CURVE_BITS \
|
|
)
|
|
|
|
/** The maximum size of a block cipher supported by the implementation. */
|
|
#define PSA_MAX_BLOCK_CIPHER_BLOCK_SIZE 16
|
|
|
|
/** The size of the output of psa_mac_sign_finish(), in bytes.
|
|
*
|
|
* This is also the MAC size that psa_mac_verify_finish() expects.
|
|
*
|
|
* \param key_type The type of the MAC key.
|
|
* \param key_bits The size of the MAC key in bits.
|
|
* \param alg A MAC algorithm (\c PSA_ALG_XXX value such that
|
|
* #PSA_ALG_IS_MAC(alg) is true).
|
|
*
|
|
* \return The MAC size for the specified algorithm with
|
|
* the specified key parameters.
|
|
* \return 0 if the MAC algorithm is not recognized.
|
|
* \return Either 0 or the correct size for a MAC algorithm that
|
|
* the implementation recognizes, but does not support.
|
|
* \return Unspecified if the key parameters are not consistent
|
|
* with the algorithm.
|
|
*/
|
|
#define PSA_MAC_FINAL_SIZE(key_type, key_bits, alg) \
|
|
((alg) & PSA_ALG_MAC_TRUNCATION_MASK ? PSA_MAC_TRUNCATED_LENGTH(alg) : \
|
|
PSA_ALG_IS_HMAC(alg) ? PSA_HASH_SIZE(PSA_ALG_HMAC_GET_HASH(alg)) : \
|
|
PSA_ALG_IS_BLOCK_CIPHER_MAC(alg) ? PSA_BLOCK_CIPHER_BLOCK_SIZE(key_type) : \
|
|
((void)(key_type), (void)(key_bits), 0))
|
|
|
|
/** The maximum size of the output of psa_aead_encrypt(), in bytes.
|
|
*
|
|
* If the size of the ciphertext buffer is at least this large, it is
|
|
* guaranteed that psa_aead_encrypt() will not fail due to an
|
|
* insufficient buffer size. Depending on the algorithm, the actual size of
|
|
* the ciphertext may be smaller.
|
|
*
|
|
* \param alg An AEAD algorithm
|
|
* (\c PSA_ALG_XXX value such that
|
|
* #PSA_ALG_IS_AEAD(alg) is true).
|
|
* \param plaintext_length Size of the plaintext in bytes.
|
|
*
|
|
* \return The AEAD ciphertext size for the specified
|
|
* algorithm.
|
|
* If the AEAD algorithm is not recognized, return 0.
|
|
* An implementation may return either 0 or a
|
|
* correct size for an AEAD algorithm that it
|
|
* recognizes, but does not support.
|
|
*/
|
|
#define PSA_AEAD_ENCRYPT_OUTPUT_SIZE(alg, plaintext_length) \
|
|
(PSA_AEAD_TAG_LENGTH(alg) != 0 ? \
|
|
(plaintext_length) + PSA_AEAD_TAG_LENGTH(alg) : \
|
|
0)
|
|
|
|
/** The maximum size of the output of psa_aead_decrypt(), in bytes.
|
|
*
|
|
* If the size of the plaintext buffer is at least this large, it is
|
|
* guaranteed that psa_aead_decrypt() will not fail due to an
|
|
* insufficient buffer size. Depending on the algorithm, the actual size of
|
|
* the plaintext may be smaller.
|
|
*
|
|
* \param alg An AEAD algorithm
|
|
* (\c PSA_ALG_XXX value such that
|
|
* #PSA_ALG_IS_AEAD(alg) is true).
|
|
* \param ciphertext_length Size of the plaintext in bytes.
|
|
*
|
|
* \return The AEAD ciphertext size for the specified
|
|
* algorithm.
|
|
* If the AEAD algorithm is not recognized, return 0.
|
|
* An implementation may return either 0 or a
|
|
* correct size for an AEAD algorithm that it
|
|
* recognizes, but does not support.
|
|
*/
|
|
#define PSA_AEAD_DECRYPT_OUTPUT_SIZE(alg, ciphertext_length) \
|
|
(PSA_AEAD_TAG_LENGTH(alg) != 0 ? \
|
|
(plaintext_length) - PSA_AEAD_TAG_LENGTH(alg) : \
|
|
0)
|
|
|
|
/** Safe signature buffer size for psa_asymmetric_sign().
|
|
*
|
|
* This macro returns a safe buffer size for a signature using a key
|
|
* of the specified type and size, with the specified algorithm.
|
|
* Note that the actual size of the signature may be smaller
|
|
* (some algorithms produce a variable-size signature).
|
|
*
|
|
* \warning This function may call its arguments multiple times or
|
|
* zero times, so you should not pass arguments that contain
|
|
* side effects.
|
|
*
|
|
* \param key_type An asymmetric key type (this may indifferently be a
|
|
* key pair type or a public key type).
|
|
* \param key_bits The size of the key in bits.
|
|
* \param alg The signature algorithm.
|
|
*
|
|
* \return If the parameters are valid and supported, return
|
|
* a buffer size in bytes that guarantees that
|
|
* psa_asymmetric_sign() will not fail with
|
|
* #PSA_ERROR_BUFFER_TOO_SMALL.
|
|
* If the parameters are a valid combination that is not supported
|
|
* by the implementation, this macro either shall return either a
|
|
* sensible size or 0.
|
|
* If the parameters are not valid, the
|
|
* return value is unspecified.
|
|
*/
|
|
#define PSA_ASYMMETRIC_SIGN_OUTPUT_SIZE(key_type, key_bits, alg) \
|
|
(PSA_KEY_TYPE_IS_RSA(key_type) ? ((void)alg, PSA_BITS_TO_BYTES(key_bits)) : \
|
|
PSA_KEY_TYPE_IS_ECC(key_type) ? PSA_ECDSA_SIGNATURE_SIZE(key_bits) : \
|
|
((void)alg, 0))
|
|
|
|
/** Safe output buffer size for psa_asymmetric_encrypt().
|
|
*
|
|
* This macro returns a safe buffer size for a ciphertext produced using
|
|
* a key of the specified type and size, with the specified algorithm.
|
|
* Note that the actual size of the ciphertext may be smaller, depending
|
|
* on the algorithm.
|
|
*
|
|
* \warning This function may call its arguments multiple times or
|
|
* zero times, so you should not pass arguments that contain
|
|
* side effects.
|
|
*
|
|
* \param key_type An asymmetric key type (this may indifferently be a
|
|
* key pair type or a public key type).
|
|
* \param key_bits The size of the key in bits.
|
|
* \param alg The signature algorithm.
|
|
*
|
|
* \return If the parameters are valid and supported, return
|
|
* a buffer size in bytes that guarantees that
|
|
* psa_asymmetric_encrypt() will not fail with
|
|
* #PSA_ERROR_BUFFER_TOO_SMALL.
|
|
* If the parameters are a valid combination that is not supported
|
|
* by the implementation, this macro either shall return either a
|
|
* sensible size or 0.
|
|
* If the parameters are not valid, the
|
|
* return value is unspecified.
|
|
*/
|
|
#define PSA_ASYMMETRIC_ENCRYPT_OUTPUT_SIZE(key_type, key_bits, alg) \
|
|
(PSA_KEY_TYPE_IS_RSA(key_type) ? \
|
|
((void)alg, PSA_BITS_TO_BYTES(key_bits)) : \
|
|
0)
|
|
|
|
/** Safe output buffer size for psa_asymmetric_decrypt().
|
|
*
|
|
* This macro returns a safe buffer size for a ciphertext produced using
|
|
* a key of the specified type and size, with the specified algorithm.
|
|
* Note that the actual size of the ciphertext may be smaller, depending
|
|
* on the algorithm.
|
|
*
|
|
* \warning This function may call its arguments multiple times or
|
|
* zero times, so you should not pass arguments that contain
|
|
* side effects.
|
|
*
|
|
* \param key_type An asymmetric key type (this may indifferently be a
|
|
* key pair type or a public key type).
|
|
* \param key_bits The size of the key in bits.
|
|
* \param alg The signature algorithm.
|
|
*
|
|
* \return If the parameters are valid and supported, return
|
|
* a buffer size in bytes that guarantees that
|
|
* psa_asymmetric_decrypt() will not fail with
|
|
* #PSA_ERROR_BUFFER_TOO_SMALL.
|
|
* If the parameters are a valid combination that is not supported
|
|
* by the implementation, this macro either shall return either a
|
|
* sensible size or 0.
|
|
* If the parameters are not valid, the
|
|
* return value is unspecified.
|
|
*/
|
|
#define PSA_ASYMMETRIC_DECRYPT_OUTPUT_SIZE(key_type, key_bits, alg) \
|
|
(PSA_KEY_TYPE_IS_RSA(key_type) ? \
|
|
PSA_BITS_TO_BYTES(key_bits) - PSA_RSA_MINIMUM_PADDING_SIZE(alg) : \
|
|
0)
|
|
|
|
/* Maximum size of the ASN.1 encoding of an INTEGER with the specified
|
|
* number of bits.
|
|
*
|
|
* This definition assumes that bits <= 2^19 - 9 so that the length field
|
|
* is at most 3 bytes. The length of the encoding is the length of the
|
|
* bit string padded to a whole number of bytes plus:
|
|
* - 1 type byte;
|
|
* - 1 to 3 length bytes;
|
|
* - 0 to 1 bytes of leading 0 due to the sign bit.
|
|
*/
|
|
#define PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(bits) \
|
|
((bits) / 8 + 5)
|
|
|
|
/* Maximum size of the export encoding of an RSA public key.
|
|
* Assumes that the public exponent is less than 2^32.
|
|
*
|
|
* SubjectPublicKeyInfo ::= SEQUENCE {
|
|
* algorithm AlgorithmIdentifier,
|
|
* subjectPublicKey BIT STRING } -- contains RSAPublicKey
|
|
* AlgorithmIdentifier ::= SEQUENCE {
|
|
* algorithm OBJECT IDENTIFIER,
|
|
* parameters NULL }
|
|
* RSAPublicKey ::= SEQUENCE {
|
|
* modulus INTEGER, -- n
|
|
* publicExponent INTEGER } -- e
|
|
*
|
|
* - 3 * 4 bytes of SEQUENCE overhead;
|
|
* - 1 + 1 + 9 bytes of algorithm (RSA OID);
|
|
* - 2 bytes of NULL;
|
|
* - 4 bytes of BIT STRING overhead;
|
|
* - n : INTEGER;
|
|
* - 7 bytes for the public exponent.
|
|
*/
|
|
#define PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(key_bits) \
|
|
(PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(key_bits) + 36)
|
|
|
|
/* Maximum size of the export encoding of an RSA key pair.
|
|
* Assumes thatthe public exponent is less than 2^32 and that the size
|
|
* difference between the two primes is at most 1 bit.
|
|
*
|
|
* RSAPrivateKey ::= SEQUENCE {
|
|
* version Version, -- 0
|
|
* modulus INTEGER, -- N-bit
|
|
* publicExponent INTEGER, -- 32-bit
|
|
* privateExponent INTEGER, -- N-bit
|
|
* prime1 INTEGER, -- N/2-bit
|
|
* prime2 INTEGER, -- N/2-bit
|
|
* exponent1 INTEGER, -- N/2-bit
|
|
* exponent2 INTEGER, -- N/2-bit
|
|
* coefficient INTEGER, -- N/2-bit
|
|
* }
|
|
*
|
|
* - 4 bytes of SEQUENCE overhead;
|
|
* - 3 bytes of version;
|
|
* - 7 half-size INTEGERs plus 2 full-size INTEGERs,
|
|
* overapproximated as 9 half-size INTEGERS;
|
|
* - 7 bytes for the public exponent.
|
|
*/
|
|
#define PSA_KEY_EXPORT_RSA_KEYPAIR_MAX_SIZE(key_bits) \
|
|
(9 * PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE((key_bits) / 2 + 1) + 14)
|
|
|
|
/* Maximum size of the export encoding of a DSA public key.
|
|
*
|
|
* SubjectPublicKeyInfo ::= SEQUENCE {
|
|
* algorithm AlgorithmIdentifier,
|
|
* subjectPublicKey BIT STRING } -- contains DSAPublicKey
|
|
* AlgorithmIdentifier ::= SEQUENCE {
|
|
* algorithm OBJECT IDENTIFIER,
|
|
* parameters Dss-Parms } -- SEQUENCE of 3 INTEGERs
|
|
* DSAPublicKey ::= INTEGER -- public key, Y
|
|
*
|
|
* - 3 * 4 bytes of SEQUENCE overhead;
|
|
* - 1 + 1 + 7 bytes of algorithm (DSA OID);
|
|
* - 4 bytes of BIT STRING overhead;
|
|
* - 3 full-size INTEGERs (p, g, y);
|
|
* - 1 + 1 + 32 bytes for 1 sub-size INTEGER (q <= 256 bits).
|
|
*/
|
|
#define PSA_KEY_EXPORT_DSA_PUBLIC_KEY_MAX_SIZE(key_bits) \
|
|
(PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(key_bits) * 3 + 59)
|
|
|
|
/* Maximum size of the export encoding of a DSA key pair.
|
|
*
|
|
* DSAPrivateKey ::= SEQUENCE {
|
|
* version Version, -- 0
|
|
* prime INTEGER, -- p
|
|
* subprime INTEGER, -- q
|
|
* generator INTEGER, -- g
|
|
* public INTEGER, -- y
|
|
* private INTEGER, -- x
|
|
* }
|
|
*
|
|
* - 4 bytes of SEQUENCE overhead;
|
|
* - 3 bytes of version;
|
|
* - 3 full-size INTEGERs (p, g, y);
|
|
* - 2 * (1 + 1 + 32) bytes for 2 sub-size INTEGERs (q, x <= 256 bits).
|
|
*/
|
|
#define PSA_KEY_EXPORT_DSA_KEYPAIR_MAX_SIZE(key_bits) \
|
|
(PSA_KEY_EXPORT_ASN1_INTEGER_MAX_SIZE(key_bits) * 3 + 75)
|
|
|
|
/* Maximum size of the export encoding of an ECC public key.
|
|
*
|
|
* SubjectPublicKeyInfo ::= SEQUENCE {
|
|
* algorithm AlgorithmIdentifier,
|
|
* subjectPublicKey BIT STRING } -- contains ECPoint
|
|
* AlgorithmIdentifier ::= SEQUENCE {
|
|
* algorithm OBJECT IDENTIFIER,
|
|
* parameters OBJECT IDENTIFIER } -- namedCurve
|
|
* ECPoint ::= ...
|
|
* -- first 8 bits: 0x04;
|
|
* -- then x_P as a `ceiling(m/8)`-byte string, big endian;
|
|
* -- then y_P as a `ceiling(m/8)`-byte string, big endian;
|
|
* -- where `m` is the bit size associated with the curve.
|
|
*
|
|
* - 2 * 4 bytes of SEQUENCE overhead;
|
|
* - 1 + 1 + 7 bytes of algorithm (id-ecPublicKey OID);
|
|
* - 1 + 1 + 12 bytes of namedCurve OID;
|
|
* - 4 bytes of BIT STRING overhead;
|
|
* - 1 byte + 2 * point size in ECPoint.
|
|
*/
|
|
#define PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(key_bits) \
|
|
(2 * PSA_BITS_TO_BYTES(key_bits) + 36)
|
|
|
|
/* Maximum size of the export encoding of an ECC key pair.
|
|
*
|
|
* An ECC key pair is represented by the secret value.
|
|
*/
|
|
#define PSA_KEY_EXPORT_ECC_KEYPAIR_MAX_SIZE(key_bits) \
|
|
(PSA_BITS_TO_BYTES(key_bits))
|
|
|
|
/** Safe output buffer size for psa_export_key() or psa_export_public_key().
|
|
*
|
|
* This macro returns a compile-time constant if its arguments are
|
|
* compile-time constants.
|
|
*
|
|
* \warning This function may call its arguments multiple times or
|
|
* zero times, so you should not pass arguments that contain
|
|
* side effects.
|
|
*
|
|
* The following code illustrates how to allocate enough memory to export
|
|
* a key by querying the key type and size at runtime.
|
|
* \code{c}
|
|
* psa_key_type_t key_type;
|
|
* size_t key_bits;
|
|
* psa_status_t status;
|
|
* status = psa_get_key_information(key, &key_type, &key_bits);
|
|
* if (status != PSA_SUCCESS) handle_error(...);
|
|
* size_t buffer_size = PSA_KEY_EXPORT_MAX_SIZE(key_type, key_bits);
|
|
* unsigned char *buffer = malloc(buffer_size);
|
|
* if (buffer != NULL) handle_error(...);
|
|
* size_t buffer_length;
|
|
* status = psa_export_key(key, buffer, buffer_size, &buffer_length);
|
|
* if (status != PSA_SUCCESS) handle_error(...);
|
|
* \endcode
|
|
*
|
|
* For psa_export_public_key(), calculate the buffer size from the
|
|
* public key type. You can use the macro #PSA_KEY_TYPE_PUBLIC_KEY_OF_KEYPAIR
|
|
* to convert a key pair type to the corresponding public key type.
|
|
* \code{c}
|
|
* psa_key_type_t key_type;
|
|
* size_t key_bits;
|
|
* psa_status_t status;
|
|
* status = psa_get_key_information(key, &key_type, &key_bits);
|
|
* if (status != PSA_SUCCESS) handle_error(...);
|
|
* psa_key_type_t public_key_type = PSA_KEY_TYPE_PUBLIC_KEY_OF_KEYPAIR(key_type);
|
|
* size_t buffer_size = PSA_KEY_EXPORT_MAX_SIZE(public_key_type, key_bits);
|
|
* unsigned char *buffer = malloc(buffer_size);
|
|
* if (buffer != NULL) handle_error(...);
|
|
* size_t buffer_length;
|
|
* status = psa_export_public_key(key, buffer, buffer_size, &buffer_length);
|
|
* if (status != PSA_SUCCESS) handle_error(...);
|
|
* \endcode
|
|
*
|
|
* \param key_type A supported key type.
|
|
* \param key_bits The size of the key in bits.
|
|
*
|
|
* \return If the parameters are valid and supported, return
|
|
* a buffer size in bytes that guarantees that
|
|
* psa_asymmetric_sign() will not fail with
|
|
* #PSA_ERROR_BUFFER_TOO_SMALL.
|
|
* If the parameters are a valid combination that is not supported
|
|
* by the implementation, this macro either shall return either a
|
|
* sensible size or 0.
|
|
* If the parameters are not valid, the
|
|
* return value is unspecified.
|
|
*/
|
|
#define PSA_KEY_EXPORT_MAX_SIZE(key_type, key_bits) \
|
|
(PSA_KEY_TYPE_IS_UNSTRUCTURED(key_type) ? PSA_BITS_TO_BYTES(key_bits) : \
|
|
(key_type) == PSA_KEY_TYPE_RSA_KEYPAIR ? PSA_KEY_EXPORT_RSA_KEYPAIR_MAX_SIZE(key_bits) : \
|
|
(key_type) == PSA_KEY_TYPE_RSA_PUBLIC_KEY ? PSA_KEY_EXPORT_RSA_PUBLIC_KEY_MAX_SIZE(key_bits) : \
|
|
(key_type) == PSA_KEY_TYPE_DSA_KEYPAIR ? PSA_KEY_EXPORT_DSA_KEYPAIR_MAX_SIZE(key_bits) : \
|
|
(key_type) == PSA_KEY_TYPE_DSA_PUBLIC_KEY ? PSA_KEY_EXPORT_DSA_PUBLIC_KEY_MAX_SIZE(key_bits) : \
|
|
PSA_KEY_TYPE_IS_ECC_KEYPAIR(key_type) ? PSA_KEY_EXPORT_ECC_KEYPAIR_MAX_SIZE(key_bits) : \
|
|
PSA_KEY_TYPE_IS_ECC_PUBLIC_KEY(key_type) ? PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(key_bits) : \
|
|
0)
|
|
|
|
#endif /* PSA_CRYPTO_SIZES_H */
|