Algorithm encoding: add flag bit PSA_ALG_AEAD_FROM_BLOCK_FLAG

Make it easy to distinguish generic constructions on top of block
ciphers, such as CCM or GCM, from specialized algorithms such as
Chacha20-Poly1305.
This commit is contained in:
Gilles Peskine 2019-05-06 15:10:16 +02:00
parent d22b6c4f89
commit 679693ee49
3 changed files with 27 additions and 4 deletions

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@ -874,13 +874,34 @@
*/
#define PSA_ALG_CBC_PKCS7 ((psa_algorithm_t)0x04600101)
#define PSA_ALG_AEAD_FROM_BLOCK_FLAG ((psa_algorithm_t)0x00400000)
/** Whether the specified algorithm is an AEAD mode on a block cipher.
*
* \param alg An algorithm identifier (value of type #psa_algorithm_t).
*
* \return 1 if \p alg is an AEAD algorithm which is an AEAD mode based on
* a block cipher, 0 otherwise.
* This macro may return either 0 or 1 if \p alg is not a supported
* algorithm identifier.
*/
#define PSA_ALG_IS_AEAD_ON_BLOCK_CIPHER(alg) \
(((alg) & (PSA_ALG_CATEGORY_MASK | PSA_ALG_AEAD_FROM_BLOCK_FLAG)) == \
(PSA_ALG_CATEGORY_AEAD | PSA_ALG_AEAD_FROM_BLOCK_FLAG))
/** The CCM authenticated encryption algorithm.
*/
#define PSA_ALG_CCM ((psa_algorithm_t)0x06001001)
#define PSA_ALG_CCM ((psa_algorithm_t)0x06401001)
/** The GCM authenticated encryption algorithm.
*/
#define PSA_ALG_GCM ((psa_algorithm_t)0x06001002)
#define PSA_ALG_GCM ((psa_algorithm_t)0x06401002)
/** The Chacha20-Poly1305 AEAD algorithm.
*
* The ChaCha20_Poly1305 construction is defined in RFC 7539.
*/
#define PSA_ALG_CHACHA20_POLY1305 ((psa_algorithm_t)0x06001005)
/* In the encoding of a AEAD algorithm, the bits corresponding to
* PSA_ALG_AEAD_TAG_LENGTH_MASK encode the length of the AEAD tag.

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@ -192,11 +192,11 @@ cipher_algorithm:PSA_ALG_XTS:0
AEAD: CCM
depends_on:MBEDTLS_CCM_C
aead_algorithm:PSA_ALG_CCM:0:16
aead_algorithm:PSA_ALG_CCM:ALG_IS_AEAD_ON_BLOCK_CIPHER:16
AEAD: GCM
depends_on:MBEDTLS_GCM_C
aead_algorithm:PSA_ALG_GCM:0:16
aead_algorithm:PSA_ALG_GCM:ALG_IS_AEAD_ON_BLOCK_CIPHER:16
Asymmetric signature: RSA PKCS#1 v1.5 raw
depends_on:MBEDTLS_RSA_C:MBEDTLS_PKCS1_V15

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@ -36,6 +36,7 @@
#define ALG_IS_ECDH ( 1u << 18 )
#define ALG_IS_WILDCARD ( 1u << 19 )
#define ALG_IS_RAW_KEY_AGREEMENT ( 1u << 20 )
#define ALG_IS_AEAD_ON_BLOCK_CIPHER ( 1u << 21 )
/* Flags for key type classification macros. There is a flag for every
* key type classification macro PSA_KEY_TYPE_IS_xxx except for some that
@ -77,6 +78,7 @@ void algorithm_classification( psa_algorithm_t alg, unsigned flags )
TEST_CLASSIFICATION_MACRO( ALG_IS_ECDH, alg, flags );
TEST_CLASSIFICATION_MACRO( ALG_IS_FFDH, alg, flags );
TEST_CLASSIFICATION_MACRO( ALG_IS_RAW_KEY_AGREEMENT, alg, flags );
TEST_CLASSIFICATION_MACRO( ALG_IS_AEAD_ON_BLOCK_CIPHER, alg, flags );
exit: ;
}