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.
diff --git a/include/psa/crypto_values.h b/include/psa/crypto_values.h
index eddf632..d01367d 100644
--- a/include/psa/crypto_values.h
+++ b/include/psa/crypto_values.h
@@ -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.
diff --git a/tests/suites/test_suite_psa_crypto_metadata.data b/tests/suites/test_suite_psa_crypto_metadata.data
index edb09a8..45aef10 100644
--- a/tests/suites/test_suite_psa_crypto_metadata.data
+++ b/tests/suites/test_suite_psa_crypto_metadata.data
@@ -192,11 +192,11 @@
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
diff --git a/tests/suites/test_suite_psa_crypto_metadata.function b/tests/suites/test_suite_psa_crypto_metadata.function
index 1bc8d64..0e69946 100644
--- a/tests/suites/test_suite_psa_crypto_metadata.function
+++ b/tests/suites/test_suite_psa_crypto_metadata.function
@@ -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 @@
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: ;
}