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.
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index d9ab832..f016dfa 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -5244,7 +5244,11 @@
#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 @@
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 @@
}
#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
*/