Move out common PSA code from mbedtls_ssl_tls13_generate_handshake_keys/mbedtls_ssl_tls13_generate_application_keys

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
This commit is contained in:
Neil Armstrong 2022-05-17 09:24:52 +02:00
parent e3b0b8ab67
commit b818e16b29

View file

@ -1188,6 +1188,36 @@ int mbedtls_ssl_tls13_key_schedule_stage_early( mbedtls_ssl_context *ssl )
return( 0 ); return( 0 );
} }
static int mbedtls_ssl_tls13_get_cipher_key_info(
const mbedtls_ssl_ciphersuite_t *ciphersuite_info,
size_t *key_len, size_t *iv_len )
{
psa_key_type_t key_type;
psa_algorithm_t alg;
size_t taglen;
size_t key_bits;
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
if( ciphersuite_info->flags & MBEDTLS_CIPHERSUITE_SHORT_TAG )
taglen = 8;
else
taglen = 16;
status = mbedtls_ssl_cipher_to_psa( ciphersuite_info->cipher, taglen,
&alg, &key_type, &key_bits );
if( status != PSA_SUCCESS )
return psa_ssl_status_to_mbedtls( status );
*key_len = PSA_BITS_TO_BYTES( key_bits );
if( PSA_ALG_IS_AEAD( alg ) )
*iv_len = 12;
else
*iv_len = PSA_CIPHER_IV_LENGTH( key_type, alg );
return 0;
}
/* mbedtls_ssl_tls13_generate_handshake_keys() generates keys necessary for /* mbedtls_ssl_tls13_generate_handshake_keys() generates keys necessary for
* protecting the handshake messages, as described in Section 7 of TLS 1.3. */ * protecting the handshake messages, as described in Section 7 of TLS 1.3. */
int mbedtls_ssl_tls13_generate_handshake_keys( mbedtls_ssl_context *ssl, int mbedtls_ssl_tls13_generate_handshake_keys( mbedtls_ssl_context *ssl,
@ -1203,11 +1233,6 @@ int mbedtls_ssl_tls13_generate_handshake_keys( mbedtls_ssl_context *ssl,
unsigned char transcript[MBEDTLS_TLS1_3_MD_MAX_SIZE]; unsigned char transcript[MBEDTLS_TLS1_3_MD_MAX_SIZE];
size_t transcript_len; size_t transcript_len;
psa_key_type_t key_type;
psa_algorithm_t alg;
size_t key_bits;
size_t taglen;
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
size_t key_len, iv_len; size_t key_len, iv_len;
mbedtls_ssl_handshake_params *handshake = ssl->handshake; mbedtls_ssl_handshake_params *handshake = ssl->handshake;
@ -1216,27 +1241,14 @@ int mbedtls_ssl_tls13_generate_handshake_keys( mbedtls_ssl_context *ssl,
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> mbedtls_ssl_tls13_generate_handshake_keys" ) ); MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> mbedtls_ssl_tls13_generate_handshake_keys" ) );
if( ciphersuite_info->flags & MBEDTLS_CIPHERSUITE_SHORT_TAG ) ret = mbedtls_ssl_tls13_get_cipher_key_info( ciphersuite_info,
taglen = 8; &key_len, &iv_len );
else if( ret != 0 )
taglen = 16;
status = mbedtls_ssl_cipher_to_psa( ciphersuite_info->cipher, taglen,
&alg, &key_type, &key_bits );
if( status != PSA_SUCCESS )
{ {
ret = psa_ssl_status_to_mbedtls( status ); MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_tls13_get_cipher_key_info", ret );
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_cipher_to_psa", ret );
return ret; return ret;
} }
key_len = PSA_BITS_TO_BYTES( key_bits );
if( PSA_ALG_IS_AEAD( alg ) )
iv_len = 12;
else
iv_len = PSA_CIPHER_IV_LENGTH( key_type, alg );
md_type = ciphersuite_info->mac; md_type = ciphersuite_info->mac;
hash_alg = mbedtls_psa_translate_md( ciphersuite_info->mac ); hash_alg = mbedtls_psa_translate_md( ciphersuite_info->mac );
@ -1429,38 +1441,20 @@ int mbedtls_ssl_tls13_generate_application_keys(
size_t hash_len; size_t hash_len;
/* Variables relating to the cipher for the chosen ciphersuite. */ /* Variables relating to the cipher for the chosen ciphersuite. */
psa_key_type_t key_type;
psa_algorithm_t alg;
size_t key_bits;
size_t taglen;
psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
size_t key_len, iv_len; size_t key_len, iv_len;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> derive application traffic keys" ) ); MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> derive application traffic keys" ) );
/* Extract basic information about hash and ciphersuite */ /* Extract basic information about hash and ciphersuite */
if( handshake->ciphersuite_info->flags & MBEDTLS_CIPHERSUITE_SHORT_TAG ) ret = mbedtls_ssl_tls13_get_cipher_key_info( handshake->ciphersuite_info,
taglen = 8; &key_len, &iv_len );
else if( ret != 0 )
taglen = 16;
status = mbedtls_ssl_cipher_to_psa( handshake->ciphersuite_info->cipher,
taglen, &alg, &key_type, &key_bits );
if( status != PSA_SUCCESS )
{ {
ret = psa_ssl_status_to_mbedtls( status ); MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_tls13_get_cipher_key_info", ret );
MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_cipher_to_psa", ret );
goto cleanup; goto cleanup;
} }
key_len = PSA_BITS_TO_BYTES( key_bits );
if( PSA_ALG_IS_AEAD( alg ) )
iv_len = 12;
else
iv_len = PSA_CIPHER_IV_LENGTH( key_type, alg );
md_type = handshake->ciphersuite_info->mac; md_type = handshake->ciphersuite_info->mac;
hash_alg = mbedtls_psa_translate_md( handshake->ciphersuite_info->mac ); hash_alg = mbedtls_psa_translate_md( handshake->ciphersuite_info->mac );