Implement PSA-based PSK-to-MS derivation in mbedtls_ssl_derive_keys

This commit is contained in:
Hanno Becker 2018-10-23 15:26:22 +01:00
parent 35b23c7484
commit 7d0a569d38

View file

@ -607,6 +607,28 @@ static void ssl_calc_finished_tls_sha384( mbedtls_ssl_context *, unsigned char *
#endif
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
#if defined(MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED) && \
defined(MBEDTLS_USE_PSA_CRYPTO)
static int ssl_use_opaque_psk( mbedtls_ssl_context const *ssl )
{
if( ssl->conf->f_psk != NULL )
{
/* If we've used a callback to select the PSK,
* the static configuration is irrelevant. */
if( ssl->handshake->psk_opaque != 0 )
return( 1 );
return( 0 );
}
if( ssl->conf->psk_opaque != 0 )
return( 1 );
return( 0 );
}
#endif /* MBEDTLS_USE_PSA_CRYPTO &&
MBEDTLS_KEY_EXCHANGE__SOME__PSK_ENABLED */
int mbedtls_ssl_derive_keys( mbedtls_ssl_context *ssl )
{
int ret = 0;
@ -758,21 +780,70 @@ int mbedtls_ssl_derive_keys( mbedtls_ssl_context *ssl )
}
#endif /* MBEDTLS_SSL_EXTENDED_MS_ENABLED */
ret = handshake->tls_prf( handshake->premaster, handshake->pmslen,
lbl, salt, salt_len,
session->master, 48 );
if( ret != 0 )
#if defined(MBEDTLS_USE_PSA_CRYPTO) && \
defined(MBEDTLS_KEY_EXCHANGE_PSK_ENABLED)
if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK &&
ssl->minor_ver == MBEDTLS_SSL_MINOR_VERSION_3 &&
ssl_use_opaque_psk( ssl ) == 1 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "prf", ret );
return( ret );
/* Perform PSK-to-MS expansion in a single step. */
psa_status_t status;
psa_algorithm_t alg;
psa_crypto_generator_t generator = PSA_CRYPTO_GENERATOR_INIT;
psa_key_slot_t psk;
MBEDTLS_SSL_DEBUG_MSG( 2, ( "perform PSA-based PSK-to-MS expansion" ) );
psk = ssl->conf->psk_opaque;
if( ssl->handshake->psk_opaque != 0 )
psk = ssl->handshake->psk_opaque;
if( md_type == MBEDTLS_MD_SHA384 )
alg = PSA_ALG_TLS12_PSK_TO_MS(PSA_ALG_SHA_384);
else
alg = PSA_ALG_TLS12_PSK_TO_MS(PSA_ALG_SHA_256);
status = psa_key_derivation( &generator, psk, alg,
salt, salt_len,
(unsigned char const *) lbl,
(size_t) strlen( lbl ),
48 );
if( status != PSA_SUCCESS )
{
psa_generator_abort( &generator );
return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
}
status = psa_generator_read( &generator, session->master, 48 );
if( status != PSA_SUCCESS )
{
psa_generator_abort( &generator );
return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
}
status = psa_generator_abort( &generator );
if( status != PSA_SUCCESS )
return( MBEDTLS_ERR_SSL_HW_ACCEL_FAILED );
}
else
#endif
{
ret = handshake->tls_prf( handshake->premaster, handshake->pmslen,
lbl, salt, salt_len,
session->master, 48 );
if( ret != 0 )
{
MBEDTLS_SSL_DEBUG_RET( 1, "prf", ret );
return( ret );
}
MBEDTLS_SSL_DEBUG_BUF( 3, "premaster secret",
handshake->premaster,
handshake->pmslen );
MBEDTLS_SSL_DEBUG_BUF( 3, "premaster secret",
handshake->premaster,
handshake->pmslen );
mbedtls_platform_zeroize( handshake->premaster,
sizeof(handshake->premaster) );
mbedtls_platform_zeroize( handshake->premaster,
sizeof(handshake->premaster) );
}
}
/*