Remember suitable hash function for any signature algorithm.

This commit changes `ssl_parse_signature_algorithms_ext` to remember
one suitable ( := supported by client and by our config ) hash
algorithm per signature algorithm.

It also modifies the ciphersuite checking function
`ssl_ciphersuite_match` to refuse a suite if there
is no suitable hash algorithm.

Finally, it adds the corresponding entry to the ChangeLog.
This commit is contained in:
Hanno Becker 2017-04-28 17:15:26 +01:00
parent 1aa267cbc3
commit 7e5437a972
7 changed files with 307 additions and 33 deletions
library

View file

@ -5244,7 +5244,11 @@ static void ssl_handshake_params_init( mbedtls_ssl_handshake_params *handshake )
#endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
handshake->update_checksum = ssl_update_checksum_start;
handshake->sig_alg = MBEDTLS_SSL_HASH_SHA1;
#if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
mbedtls_ssl_sig_hash_set_init( &handshake->hash_algs );
#endif
#if defined(MBEDTLS_DHM_C)
mbedtls_dhm_init( &handshake->dhm_ctx );
@ -7375,6 +7379,19 @@ unsigned char mbedtls_ssl_sig_from_pk( mbedtls_pk_context *pk )
return( MBEDTLS_SSL_SIG_ANON );
}
unsigned char mbedtls_ssl_sig_from_pk_alg( mbedtls_pk_type_t type )
{
switch( type ) {
case MBEDTLS_PK_RSA:
return( MBEDTLS_SSL_SIG_RSA );
case MBEDTLS_PK_ECDSA:
case MBEDTLS_PK_ECKEY:
return( MBEDTLS_SSL_SIG_ECDSA );
default:
return( MBEDTLS_SSL_SIG_ANON );
}
}
mbedtls_pk_type_t mbedtls_ssl_pk_alg_from_sig( unsigned char sig )
{
switch( sig )
@ -7393,6 +7410,57 @@ mbedtls_pk_type_t mbedtls_ssl_pk_alg_from_sig( unsigned char sig )
}
#endif /* MBEDTLS_PK_C && ( MBEDTLS_RSA_C || MBEDTLS_ECDSA_C ) */
#if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
/* Find an entry in a signature-hash set matching a given hash algorithm. */
mbedtls_md_type_t mbedtls_ssl_sig_hash_set_find( mbedtls_ssl_sig_hash_set_t *set,
mbedtls_pk_type_t sig_alg )
{
switch( sig_alg )
{
case MBEDTLS_PK_RSA:
return( set->rsa );
case MBEDTLS_PK_ECDSA:
return( set->ecdsa );
default:
return( MBEDTLS_MD_NONE );
}
}
/* Add a signature-hash-pair to a signature-hash set */
void mbedtls_ssl_sig_hash_set_add( mbedtls_ssl_sig_hash_set_t *set,
mbedtls_pk_type_t sig_alg,
mbedtls_md_type_t md_alg )
{
switch( sig_alg )
{
case MBEDTLS_PK_RSA:
if( set->rsa == MBEDTLS_MD_NONE )
set->rsa = md_alg;
break;
case MBEDTLS_PK_ECDSA:
if( set->ecdsa == MBEDTLS_MD_NONE )
set->ecdsa = md_alg;
break;
default:
break;
}
}
/* Allow exactly one hash algorithm for each signature. */
void mbedtls_ssl_sig_hash_set_const_hash( mbedtls_ssl_sig_hash_set_t *set,
mbedtls_md_type_t md_alg )
{
set->rsa = md_alg;
set->ecdsa = md_alg;
}
#endif /* MBEDTLS_SSL_PROTO_TLS1_2) &&
MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED */
/*
* Convert from MBEDTLS_SSL_HASH_XXX to MBEDTLS_MD_XXX
*/