diff --git a/include/psa/crypto.h b/include/psa/crypto.h index 62d392017..0269be959 100644 --- a/include/psa/crypto.h +++ b/include/psa/crypto.h @@ -756,6 +756,56 @@ typedef uint32_t psa_algorithm_t; (((alg) & (PSA_ALG_CATEGORY_MASK | PSA_ALG_MAC_SUBCATEGORY_MASK)) == \ PSA_ALG_HMAC_BASE) +#define PSA_ALG_MAC_TRUNCATION_MASK ((psa_algorithm_t)0x00003f00) +#define PSA_MAC_TRUNCATION_OFFSET 8 + +/** Macro to build a truncated MAC algorithm. + * + * A truncated MAC algorithm is identical to the corresponding MAC + * algorithm except that the MAC value for the truncated algorithm + * consists of only the first \p mac_length bytes of the MAC value + * for the untruncated algorithm. + * + * \note This macro may allow constructing algorithm identifiers that + * are not valid, either because the specified length is larger + * than the untruncated MAC or because the specified length is + * smaller than permitted by the implementation. + * + * \note It is implementation-defined whether a truncated MAC that + * is truncated to the same length as the MAC of the untruncated + * algorithm is considered identical to the untruncated algorithm + * for policy comparison purposes. + * + * \param alg A MAC algorithm identifier (value of type + * #psa_algorithm_t such that #PSA_ALG_IS_MAC(\p alg) + * is true). This may be a truncated or untruncated + * MAC algorithm. + * \param mac_length Desired length of the truncated MAC in bytes. + * + * \return The corresponding MAC algorithm with the specified + * length. + * \return Unspecified if \p alg is not a supported + * MAC algorithm or if \p mac_length is too small or + * too large for the specified MAC algorithm. + */ +#define PSA_ALG_TRUNCATED_MAC(alg, mac_length) \ + (((alg) & ~PSA_ALG_MAC_TRUNCATION_MASK) | \ + ((mac_length) << PSA_MAC_TRUNCATION_OFFSET & PSA_ALG_MAC_TRUNCATION_MASK)) + +/** Length to which a MAC algorithm is truncated. + * + * \param alg A MAC algorithm identifier (value of type + * #psa_algorithm_t such that #PSA_ALG_IS_MAC(\p alg) + * is true). + * + * \return Length of the truncated MAC in bytes. + * \return 0 if \p alg is a non-truncated MAC algorithm. + * \return Unspecified if \p alg is not a supported + * MAC algorithm. + */ +#define PSA_MAC_TRUNCATED_LENGTH(alg) \ + (((alg) & PSA_ALG_MAC_TRUNCATION_MASK) >> PSA_MAC_TRUNCATION_OFFSET) + #define PSA_ALG_CIPHER_MAC_BASE ((psa_algorithm_t)0x02c00000) #define PSA_ALG_CBC_MAC ((psa_algorithm_t)0x02c00001) #define PSA_ALG_CMAC ((psa_algorithm_t)0x02c00002) diff --git a/include/psa/crypto_sizes.h b/include/psa/crypto_sizes.h index edb240be0..c058afc38 100644 --- a/include/psa/crypto_sizes.h +++ b/include/psa/crypto_sizes.h @@ -143,7 +143,8 @@ 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. * @@ -163,7 +164,8 @@ * with the algorithm. */ #define PSA_MAC_FINAL_SIZE(key_type, key_bits, alg) \ - (PSA_ALG_IS_HMAC(alg) ? PSA_HASH_SIZE(PSA_ALG_HMAC_GET_HASH(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)) diff --git a/library/psa_crypto.c b/library/psa_crypto.c index 6fd905c8c..3411cc843 100644 --- a/library/psa_crypto.c +++ b/library/psa_crypto.c @@ -1523,8 +1523,10 @@ static psa_status_t psa_mac_setup( psa_mac_operation_t *operation, size_t key_bits; psa_key_usage_t usage = is_sign ? PSA_KEY_USAGE_SIGN : PSA_KEY_USAGE_VERIFY; + unsigned char truncated = PSA_MAC_TRUNCATED_LENGTH( alg ); + psa_algorithm_t full_length_alg = alg & ~PSA_ALG_MAC_TRUNCATION_MASK; - status = psa_mac_init( operation, alg ); + status = psa_mac_init( operation, full_length_alg ); if( status != PSA_SUCCESS ) return( status ); if( is_sign ) @@ -1536,10 +1538,11 @@ static psa_status_t psa_mac_setup( psa_mac_operation_t *operation, key_bits = psa_get_key_bits( slot ); #if defined(MBEDTLS_CMAC_C) - if( alg == PSA_ALG_CMAC ) + if( full_length_alg == PSA_ALG_CMAC ) { const mbedtls_cipher_info_t *cipher_info = - mbedtls_cipher_info_from_psa( alg, slot->type, key_bits, NULL ); + mbedtls_cipher_info_from_psa( full_length_alg, + slot->type, key_bits, NULL ); int ret; if( cipher_info == NULL ) { @@ -1553,7 +1556,7 @@ static psa_status_t psa_mac_setup( psa_mac_operation_t *operation, else #endif /* MBEDTLS_CMAC_C */ #if defined(MBEDTLS_MD_C) - if( PSA_ALG_IS_HMAC( alg ) ) + if( PSA_ALG_IS_HMAC( full_length_alg ) ) { psa_algorithm_t hash_alg = PSA_ALG_HMAC_GET_HASH( alg ); if( hash_alg == 0 ) @@ -1588,6 +1591,24 @@ static psa_status_t psa_mac_setup( psa_mac_operation_t *operation, status = PSA_ERROR_NOT_SUPPORTED; } + if( truncated == 0 ) + { + /* The "normal" case: untruncated algorithm. Nothing to do. */ + } + else if( truncated < 4 ) + { + /* Too small to make any sense. Reject. 4 bytes is too small for + * security but ancient protocols with 32-bit MACs do exist. */ + 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 ) { @@ -1682,7 +1703,11 @@ static psa_status_t psa_hmac_finish_internal( psa_hmac_internal_data *hmac, if( status != PSA_SUCCESS ) goto exit; - status = psa_hash_finish( &hmac->hash_ctx, mac, mac_size, &hash_size ); + 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_zeroize( tmp, hash_size ); @@ -1705,7 +1730,11 @@ static psa_status_t psa_mac_finish_internal( psa_mac_operation_t *operation, #if defined(MBEDTLS_CMAC_C) if( operation->alg == PSA_ALG_CMAC ) { - int ret = mbedtls_cipher_cmac_finish( &operation->ctx.cmac, mac ); + 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, mac_size ); + mbedtls_zeroize( tmp, sizeof( tmp ) ); return( mbedtls_to_psa_error( ret ) ); } else @@ -1714,7 +1743,7 @@ static psa_status_t psa_mac_finish_internal( psa_mac_operation_t *operation, if( PSA_ALG_IS_HMAC( operation->alg ) ) { return( psa_hmac_finish_internal( &operation->ctx.hmac, - mac, mac_size ) ); + mac, operation->mac_size ) ); } else #endif /* MBEDTLS_MD_C */ @@ -1793,6 +1822,8 @@ cleanup: else psa_mac_abort( operation ); + mbedtls_zeroize( actual_mac, mac_length ); + return( status ); } diff --git a/tests/suites/test_suite_psa_crypto.data b/tests/suites/test_suite_psa_crypto.data index 913c69460..b76f3071e 100644 --- a/tests/suites/test_suite_psa_crypto.data +++ b/tests/suites/test_suite_psa_crypto.data @@ -466,10 +466,86 @@ PSA MAC verify: RFC4231 Test case 7 - HMAC-SHA-512 depends_on:MBEDTLS_MD_C:MBEDTLS_SHA512_C mac_verify:PSA_KEY_TYPE_HMAC:"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa":PSA_ALG_HMAC(PSA_ALG_SHA_512):"5468697320697320612074657374207573696e672061206c6172676572207468616e20626c6f636b2d73697a65206b657920616e642061206c6172676572207468616e20626c6f636b2d73697a6520646174612e20546865206b6579206e6565647320746f20626520686173686564206265666f7265206265696e6720757365642062792074686520484d414320616c676f726974686d2e":"e37b6a775dc87dbaa4dfa9f96e5e3ffddebd71f8867289865df5a32d20cdc944b6022cac3c4982b10d5eeb55c3e4de15134676fb6de0446065c97440fa8c6a58" +PSA MAC sign: HMAC-SHA-224, truncated to 28 bytes (actual size) +depends_on:MBEDTLS_MD_C:MBEDTLS_SHA256_C +mac_sign:PSA_KEY_TYPE_HMAC:"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":PSA_ALG_TRUNCATED_MAC(PSA_ALG_HMAC(PSA_ALG_SHA_224), 28):"4869205468657265":"896fb1128abbdf196832107cd49df33f47b4b1169912ba4f53684b22" + +PSA MAC verify: HMAC-SHA-224, truncated to 28 bytes (actual size) +depends_on:MBEDTLS_MD_C:MBEDTLS_SHA256_C +mac_verify:PSA_KEY_TYPE_HMAC:"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":PSA_ALG_TRUNCATED_MAC(PSA_ALG_HMAC(PSA_ALG_SHA_224), 28):"4869205468657265":"896fb1128abbdf196832107cd49df33f47b4b1169912ba4f53684b22" + +PSA MAC sign: HMAC-SHA-512, truncated to 64 bytes (actual size) +depends_on:MBEDTLS_MD_C:MBEDTLS_SHA512_C +mac_sign:PSA_KEY_TYPE_HMAC:"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":PSA_ALG_TRUNCATED_MAC(PSA_ALG_HMAC(PSA_ALG_SHA_512), 64):"4869205468657265":"87aa7cdea5ef619d4ff0b4241a1d6cb02379f4e2ce4ec2787ad0b30545e17cdedaa833b7d6b8a702038b274eaea3f4e4be9d914eeb61f1702e696c203a126854" + +PSA MAC verify: HMAC-SHA-512, truncated to 64 bytes (actual size) +depends_on:MBEDTLS_MD_C:MBEDTLS_SHA512_C +mac_verify:PSA_KEY_TYPE_HMAC:"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":PSA_ALG_TRUNCATED_MAC(PSA_ALG_HMAC(PSA_ALG_SHA_512), 64):"4869205468657265":"87aa7cdea5ef619d4ff0b4241a1d6cb02379f4e2ce4ec2787ad0b30545e17cdedaa833b7d6b8a702038b274eaea3f4e4be9d914eeb61f1702e696c203a126854" + +PSA MAC sign: HMAC-SHA-224, truncated to 27 bytes +depends_on:MBEDTLS_MD_C:MBEDTLS_SHA256_C +mac_sign:PSA_KEY_TYPE_HMAC:"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":PSA_ALG_TRUNCATED_MAC(PSA_ALG_HMAC(PSA_ALG_SHA_224), 27):"4869205468657265":"896fb1128abbdf196832107cd49df33f47b4b1169912ba4f53684b" + +PSA MAC verify: HMAC-SHA-224, truncated to 27 bytes +depends_on:MBEDTLS_MD_C:MBEDTLS_SHA256_C +mac_verify:PSA_KEY_TYPE_HMAC:"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":PSA_ALG_TRUNCATED_MAC(PSA_ALG_HMAC(PSA_ALG_SHA_224), 27):"4869205468657265":"896fb1128abbdf196832107cd49df33f47b4b1169912ba4f53684b" + +PSA MAC sign: HMAC-SHA-512, truncated to 63 bytes +depends_on:MBEDTLS_MD_C:MBEDTLS_SHA512_C +mac_sign:PSA_KEY_TYPE_HMAC:"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":PSA_ALG_TRUNCATED_MAC(PSA_ALG_HMAC(PSA_ALG_SHA_512), 63):"4869205468657265":"87aa7cdea5ef619d4ff0b4241a1d6cb02379f4e2ce4ec2787ad0b30545e17cdedaa833b7d6b8a702038b274eaea3f4e4be9d914eeb61f1702e696c203a1268" + +PSA MAC verify: HMAC-SHA-512, truncated to 63 bytes +depends_on:MBEDTLS_MD_C:MBEDTLS_SHA512_C +mac_verify:PSA_KEY_TYPE_HMAC:"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":PSA_ALG_TRUNCATED_MAC(PSA_ALG_HMAC(PSA_ALG_SHA_512), 63):"4869205468657265":"87aa7cdea5ef619d4ff0b4241a1d6cb02379f4e2ce4ec2787ad0b30545e17cdedaa833b7d6b8a702038b274eaea3f4e4be9d914eeb61f1702e696c203a1268" + +PSA MAC sign: HMAC-SHA-224, truncated to 4 bytes +depends_on:MBEDTLS_MD_C:MBEDTLS_SHA256_C +mac_sign:PSA_KEY_TYPE_HMAC:"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":PSA_ALG_TRUNCATED_MAC(PSA_ALG_HMAC(PSA_ALG_SHA_224), 4):"4869205468657265":"896fb112" + +PSA MAC verify: HMAC-SHA-224, truncated to 4 bytes +depends_on:MBEDTLS_MD_C:MBEDTLS_SHA256_C +mac_verify:PSA_KEY_TYPE_HMAC:"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":PSA_ALG_TRUNCATED_MAC(PSA_ALG_HMAC(PSA_ALG_SHA_224), 4):"4869205468657265":"896fb112" + +PSA MAC sign: HMAC-SHA-512, truncated to 4 bytes +depends_on:MBEDTLS_MD_C:MBEDTLS_SHA512_C +mac_sign:PSA_KEY_TYPE_HMAC:"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":PSA_ALG_TRUNCATED_MAC(PSA_ALG_HMAC(PSA_ALG_SHA_512), 4):"4869205468657265":"87aa7cde" + +PSA MAC verify: HMAC-SHA-512, truncated to 4 bytes +depends_on:MBEDTLS_MD_C:MBEDTLS_SHA512_C +mac_verify:PSA_KEY_TYPE_HMAC:"0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b0b":PSA_ALG_TRUNCATED_MAC(PSA_ALG_HMAC(PSA_ALG_SHA_512), 4):"4869205468657265":"87aa7cde" + +PSA MAC sign: CMAC-AES-128 +depends_on:MBEDTLS_CMAC_C:MBEDTLS_AES_C +mac_sign:PSA_KEY_TYPE_AES:"2b7e151628aed2a6abf7158809cf4f3c":PSA_ALG_CMAC:"6bc1bee22e409f96e93d7e117393172aae2d8a571e03ac9c9eb76fac45af8e5130c81c46a35ce411":"dfa66747de9ae63030ca32611497c827" + PSA MAC verify: CMAC-AES-128 depends_on:MBEDTLS_CMAC_C:MBEDTLS_AES_C mac_verify:PSA_KEY_TYPE_AES:"2b7e151628aed2a6abf7158809cf4f3c":PSA_ALG_CMAC:"6bc1bee22e409f96e93d7e117393172aae2d8a571e03ac9c9eb76fac45af8e5130c81c46a35ce411":"dfa66747de9ae63030ca32611497c827" +PSA MAC sign: CMAC-AES-128, truncated to 16 bytes (actual size) +depends_on:MBEDTLS_CMAC_C:MBEDTLS_AES_C +mac_sign:PSA_KEY_TYPE_AES:"2b7e151628aed2a6abf7158809cf4f3c":PSA_ALG_TRUNCATED_MAC(PSA_ALG_CMAC, 16):"6bc1bee22e409f96e93d7e117393172aae2d8a571e03ac9c9eb76fac45af8e5130c81c46a35ce411":"dfa66747de9ae63030ca32611497c827" + +PSA MAC verify: CMAC-AES-128, truncated to 16 bytes (actual size) +depends_on:MBEDTLS_CMAC_C:MBEDTLS_AES_C +mac_verify:PSA_KEY_TYPE_AES:"2b7e151628aed2a6abf7158809cf4f3c":PSA_ALG_TRUNCATED_MAC(PSA_ALG_CMAC, 16):"6bc1bee22e409f96e93d7e117393172aae2d8a571e03ac9c9eb76fac45af8e5130c81c46a35ce411":"dfa66747de9ae63030ca32611497c827" + +PSA MAC sign: CMAC-AES-128, truncated to 15 bytes +depends_on:MBEDTLS_CMAC_C:MBEDTLS_AES_C +mac_sign:PSA_KEY_TYPE_AES:"2b7e151628aed2a6abf7158809cf4f3c":PSA_ALG_TRUNCATED_MAC(PSA_ALG_CMAC, 15):"6bc1bee22e409f96e93d7e117393172aae2d8a571e03ac9c9eb76fac45af8e5130c81c46a35ce411":"dfa66747de9ae63030ca32611497c8" + +PSA MAC verify: CMAC-AES-128, truncated to 15 bytes +depends_on:MBEDTLS_CMAC_C:MBEDTLS_AES_C +mac_verify:PSA_KEY_TYPE_AES:"2b7e151628aed2a6abf7158809cf4f3c":PSA_ALG_TRUNCATED_MAC(PSA_ALG_CMAC, 15):"6bc1bee22e409f96e93d7e117393172aae2d8a571e03ac9c9eb76fac45af8e5130c81c46a35ce411":"dfa66747de9ae63030ca32611497c8" + +PSA MAC sign: CMAC-AES-128, truncated to 4 bytes +depends_on:MBEDTLS_CMAC_C:MBEDTLS_AES_C +mac_sign:PSA_KEY_TYPE_AES:"2b7e151628aed2a6abf7158809cf4f3c":PSA_ALG_TRUNCATED_MAC(PSA_ALG_CMAC, 4):"6bc1bee22e409f96e93d7e117393172aae2d8a571e03ac9c9eb76fac45af8e5130c81c46a35ce411":"dfa66747" + +PSA MAC verify: CMAC-AES-128, truncated to 4 bytes +depends_on:MBEDTLS_CMAC_C:MBEDTLS_AES_C +mac_verify:PSA_KEY_TYPE_AES:"2b7e151628aed2a6abf7158809cf4f3c":PSA_ALG_TRUNCATED_MAC(PSA_ALG_CMAC, 4):"6bc1bee22e409f96e93d7e117393172aae2d8a571e03ac9c9eb76fac45af8e5130c81c46a35ce411":"dfa66747" + PSA cipher setup: good, AES-CTR depends_on:MBEDTLS_AES_C:MBEDTLS_CIPHER_MODE_CTR cipher_setup:PSA_KEY_TYPE_AES:"000102030405060708090a0b0c0d0e0f":PSA_ALG_CTR:PSA_SUCCESS