Sort out RSA mechanisms

* PSS needs to be parametrized by a hash.
* Don't use `_MGF1` in the names of macros for OAEP and PSS. No one
  ever uses anything else.
* Add brief documentation for the RSA signature mechanisms.
This commit is contained in:
Gilles Peskine 2018-06-26 15:53:48 +02:00 committed by itayzafrir
parent 9e73ff17d4
commit 55bf3d1171
3 changed files with 55 additions and 15 deletions

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@ -621,18 +621,52 @@ typedef uint32_t psa_algorithm_t;
#define PSA_ALG_CCM ((psa_algorithm_t)0x06000001)
#define PSA_ALG_GCM ((psa_algorithm_t)0x06000002)
#define PSA_ALG_RSA_PKCS1V15_SIGN_RAW ((psa_algorithm_t)0x10010000)
#define PSA_ALG_RSA_PSS_MGF1 ((psa_algorithm_t)0x10020000)
#define PSA_ALG_RSA_PKCS1V15_CRYPT ((psa_algorithm_t)0x12010000)
#define PSA_ALG_RSA_OAEP_MGF1_BASE ((psa_algorithm_t)0x12020000)
#define PSA_ALG_RSA_PKCS1V15_SIGN_BASE ((psa_algorithm_t)0x10020000)
/** RSA PKCS#1 v1.5 signature with hashing.
*
* This is the signature scheme defined by RFC 8017
* (PKCS#1: RSA Cryptography Specifications) under the name
* RSASSA-PKCS1-v1_5.
*
* \param hash_alg A hash algorithm (\c PSA_ALG_XXX value such that
* #PSA_ALG_IS_HASH(alg) is true).
*
* \return The corresponding RSA PKCS#1 v1.5 signature algorithm.
* \return Unspecified if \p alg is not a supported
* hash algorithm.
*/
#define PSA_ALG_RSA_PKCS1V15_SIGN(hash_alg) \
(PSA_ALG_RSA_PKCS1V15_SIGN_RAW | ((hash_alg) & PSA_ALG_HASH_MASK))
(PSA_ALG_RSA_PKCS1V15_SIGN_BASE | ((hash_alg) & PSA_ALG_HASH_MASK))
/** Raw PKCS#1 v1.5 signature.
*
* The input to this algorithm is the DigestInfo structure used by
* RFC 8017 (PKCS#1: RSA Cryptography Specifications), §9.2
* steps 3–6.
*/
#define PSA_ALG_RSA_PKCS1V15_SIGN_RAW PSA_ALG_RSA_PKCS1V15_SIGN_BASE
#define PSA_ALG_IS_RSA_PKCS1V15_SIGN(alg) \
(((alg) & ~PSA_ALG_HASH_MASK) == PSA_ALG_RSA_PKCS1V15_SIGN_RAW)
#define PSA_ALG_RSA_OAEP_MGF1(hash_alg) \
(PSA_ALG_RSA_OAEP_MGF1_RAW | ((hash_alg) & PSA_ALG_HASH_MASK))
#define PSA_ALG_IS_RSA_OAEP_MGF1(alg) \
(((alg) & ~PSA_ALG_HASH_MASK) == PSA_ALG_RSA_OAEP_MGF1_BASE)
(((alg) & ~PSA_ALG_HASH_MASK) == PSA_ALG_RSA_PKCS1V15_SIGN_BASE)
#define PSA_ALG_RSA_PSS_BASE ((psa_algorithm_t)0x10030000)
/** RSA PSS signature with hashing.
*
* This is the signature scheme defined by RFC 8017
* (PKCS#1: RSA Cryptography Specifications) under the name
* RSASSA-PSS, with the message generation function MGF1. The specified
* hash algorithm is used to hash the input message, to create the
* salted hash, and for the mask generation.
*
* \param hash_alg A hash algorithm (\c PSA_ALG_XXX value such that
* #PSA_ALG_IS_HASH(alg) is true).
*
* \return The corresponding RSA PSS signature algorithm.
* \return Unspecified if \p alg is not a supported
* hash algorithm.
*/
#define PSA_ALG_RSA_PSS(hash_alg) \
(PSA_ALG_RSA_PSS_BASE | ((hash_alg) & PSA_ALG_HASH_MASK))
#define PSA_ALG_IS_RSA_PSS(alg) \
(((alg) & ~PSA_ALG_HASH_MASK) == PSA_ALG_RSA_PSS_BASE)
/** Get the hash used by a hash-and-sign signature algorithm.
*
* A hash-and-sign algorithm is a signature algorithm which is
@ -657,6 +691,12 @@ typedef uint32_t psa_algorithm_t;
0)
#define PSA_ALG_ECDSA_RAW ((psa_algorithm_t)0x10030000)
#define PSA_ALG_RSA_PKCS1V15_CRYPT ((psa_algorithm_t)0x12020000)
#define PSA_ALG_RSA_OAEP_BASE ((psa_algorithm_t)0x12030000)
#define PSA_ALG_RSA_OAEP(hash_alg) \
(PSA_ALG_RSA_OAEP_BASE | ((hash_alg) & PSA_ALG_HASH_MASK))
#define PSA_ALG_IS_RSA_OAEP(alg) \
(((alg) & ~PSA_ALG_HASH_MASK) == PSA_ALG_RSA_OAEP_BASE)
/**@}*/

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@ -1690,7 +1690,7 @@ psa_status_t psa_asymmetric_sign( psa_key_slot_t key,
else
#endif /* MBEDTLS_PKCS1_V15 */
#if defined(MBEDTLS_PKCS1_V21)
if( alg == PSA_ALG_RSA_PSS_MGF1 )
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,
@ -1789,7 +1789,7 @@ psa_status_t psa_asymmetric_verify( psa_key_slot_t key,
else
#endif /* MBEDTLS_PKCS1_V15 */
#if defined(MBEDTLS_PKCS1_V21)
if( alg == PSA_ALG_RSA_PSS_MGF1 )
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,
@ -1872,7 +1872,7 @@ psa_status_t psa_asymmetric_encrypt( psa_key_slot_t key,
else
#endif /* MBEDTLS_PKCS1_V15 */
#if defined(MBEDTLS_PKCS1_V21)
if( PSA_ALG_IS_RSA_OAEP_MGF1( alg ) )
if( PSA_ALG_IS_RSA_OAEP( alg ) )
{
return( PSA_ERROR_NOT_SUPPORTED );
}
@ -1941,7 +1941,7 @@ psa_status_t psa_asymmetric_decrypt( psa_key_slot_t key,
else
#endif /* MBEDTLS_PKCS1_V15 */
#if defined(MBEDTLS_PKCS1_V21)
if( PSA_ALG_IS_RSA_OAEP_MGF1( alg ) )
if( PSA_ALG_IS_RSA_OAEP( alg ) )
{
return( PSA_ERROR_NOT_SUPPORTED );
}

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@ -503,7 +503,7 @@ PSA signature size: RSA keypair, 1024 bits, PKCS#1 v1.5 SHA-256
signature_size:PSA_KEY_TYPE_RSA_KEYPAIR:1024:PSA_ALG_RSA_PKCS1V15_SIGN(PSA_ALG_SHA_256):128
PSA signature size: RSA keypair, 1024 bits, PSS
signature_size:PSA_KEY_TYPE_RSA_KEYPAIR:1024:PSA_ALG_RSA_PSS_MGF1:128
signature_size:PSA_KEY_TYPE_RSA_KEYPAIR:1024:PSA_ALG_RSA_PSS( PSA_ALG_SHA_256 ):128
PSA signature size: RSA keypair, 1023 bits, PKCS#1 v1.5 raw
signature_size:PSA_KEY_TYPE_RSA_KEYPAIR:1023:PSA_ALG_RSA_PKCS1V15_SIGN_RAW:128