Implement sig_hashes
diff --git a/library/ssl_cli.c b/library/ssl_cli.c
index 40c2d4c..e2c2d3f 100644
--- a/library/ssl_cli.c
+++ b/library/ssl_cli.c
@@ -156,6 +156,7 @@
{
unsigned char *p = buf;
size_t sig_alg_len = 0;
+ const int *md;
#if defined(MBEDTLS_RSA_C) || defined(MBEDTLS_ECDSA_C)
unsigned char *sig_alg_list = buf + 6;
#endif
@@ -170,55 +171,22 @@
/*
* Prepare signature_algorithms extension (TLS 1.2)
*/
-#if defined(MBEDTLS_RSA_C)
-#if defined(MBEDTLS_SHA512_C)
- sig_alg_list[sig_alg_len++] = MBEDTLS_SSL_HASH_SHA512;
- sig_alg_list[sig_alg_len++] = MBEDTLS_SSL_SIG_RSA;
- sig_alg_list[sig_alg_len++] = MBEDTLS_SSL_HASH_SHA384;
- sig_alg_list[sig_alg_len++] = MBEDTLS_SSL_SIG_RSA;
-#endif
-#if defined(MBEDTLS_SHA256_C)
- sig_alg_list[sig_alg_len++] = MBEDTLS_SSL_HASH_SHA256;
- sig_alg_list[sig_alg_len++] = MBEDTLS_SSL_SIG_RSA;
- sig_alg_list[sig_alg_len++] = MBEDTLS_SSL_HASH_SHA224;
- sig_alg_list[sig_alg_len++] = MBEDTLS_SSL_SIG_RSA;
-#endif
-#if defined(MBEDTLS_SHA1_C)
- sig_alg_list[sig_alg_len++] = MBEDTLS_SSL_HASH_SHA1;
- sig_alg_list[sig_alg_len++] = MBEDTLS_SSL_SIG_RSA;
-#endif
-#if defined(MBEDTLS_MD5_C)
- sig_alg_list[sig_alg_len++] = MBEDTLS_SSL_HASH_MD5;
- sig_alg_list[sig_alg_len++] = MBEDTLS_SSL_SIG_RSA;
-#endif
-#endif /* MBEDTLS_RSA_C */
+ for( md = ssl->conf->sig_hashes; *md != MBEDTLS_MD_NONE; md++ )
+ {
#if defined(MBEDTLS_ECDSA_C)
-#if defined(MBEDTLS_SHA512_C)
- sig_alg_list[sig_alg_len++] = MBEDTLS_SSL_HASH_SHA512;
- sig_alg_list[sig_alg_len++] = MBEDTLS_SSL_SIG_ECDSA;
- sig_alg_list[sig_alg_len++] = MBEDTLS_SSL_HASH_SHA384;
- sig_alg_list[sig_alg_len++] = MBEDTLS_SSL_SIG_ECDSA;
+ sig_alg_list[sig_alg_len++] = mbedtls_ssl_hash_from_md_alg( *md );
+ sig_alg_list[sig_alg_len++] = MBEDTLS_SSL_SIG_ECDSA;
#endif
-#if defined(MBEDTLS_SHA256_C)
- sig_alg_list[sig_alg_len++] = MBEDTLS_SSL_HASH_SHA256;
- sig_alg_list[sig_alg_len++] = MBEDTLS_SSL_SIG_ECDSA;
- sig_alg_list[sig_alg_len++] = MBEDTLS_SSL_HASH_SHA224;
- sig_alg_list[sig_alg_len++] = MBEDTLS_SSL_SIG_ECDSA;
+#if defined(MBEDTLS_RSA_C)
+ sig_alg_list[sig_alg_len++] = mbedtls_ssl_hash_from_md_alg( *md );
+ sig_alg_list[sig_alg_len++] = MBEDTLS_SSL_SIG_RSA;
#endif
-#if defined(MBEDTLS_SHA1_C)
- sig_alg_list[sig_alg_len++] = MBEDTLS_SSL_HASH_SHA1;
- sig_alg_list[sig_alg_len++] = MBEDTLS_SSL_SIG_ECDSA;
-#endif
-#if defined(MBEDTLS_MD5_C)
- sig_alg_list[sig_alg_len++] = MBEDTLS_SSL_HASH_MD5;
- sig_alg_list[sig_alg_len++] = MBEDTLS_SSL_SIG_ECDSA;
-#endif
-#endif /* MBEDTLS_ECDSA_C */
+ }
/*
* enum {
- * none(0), mbedtls_md5(1), mbedtls_sha1(2), sha224(3), mbedtls_sha256(4), sha384(5),
- * mbedtls_sha512(6), (255)
+ * none(0), md5(1), sha1(2), sha224(3), sha256(4), sha384(5),
+ * sha512(6), (255)
* } HashAlgorithm;
*
* enum { anonymous(0), rsa(1), dsa(2), ecdsa(3), (255) }
@@ -1876,6 +1844,16 @@
return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
}
+ /*
+ * Check if the hash is acceptable
+ */
+ if( mbedtls_ssl_check_sig_hash( ssl, *md_alg ) != 0 )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "server used HashAlgorithm "
+ "that was not offered" ) );
+ return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
+ }
+
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Server used SignatureAlgorithm %d", (*p)[1] ) );
MBEDTLS_SSL_DEBUG_MSG( 2, ( "Server used HashAlgorithm %d", (*p)[0] ) );
*p += 2;
diff --git a/library/ssl_srv.c b/library/ssl_srv.c
index 554a552..457362f 100644
--- a/library/ssl_srv.c
+++ b/library/ssl_srv.c
@@ -211,7 +211,7 @@
*
* So, just look at the HashAlgorithm part.
*/
- for( md_cur = mbedtls_md_list(); *md_cur != MBEDTLS_MD_NONE; md_cur++ ) {
+ for( md_cur = ssl->conf->sig_hashes; *md_cur != MBEDTLS_MD_NONE; md_cur++ ) {
for( p = buf + 2; p < end; p += 2 ) {
if( *md_cur == (int) mbedtls_ssl_md_alg_from_hash( p[0] ) ) {
ssl->handshake->sig_alg = p[0];
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 63d2e83..9007e05 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -6788,7 +6788,7 @@
#endif /* MBEDTLS_PK_C */
/*
- * Convert between SSL_HASH_XXX and MBEDTLS_MD_XXX
+ * Convert from MBEDTLS_SSL_HASH_XXX to MBEDTLS_MD_XXX
*/
mbedtls_md_type_t mbedtls_ssl_md_alg_from_hash( unsigned char hash )
{
@@ -6819,9 +6819,41 @@
}
}
+/*
+ * Convert from MBEDTLS_MD_XXX to MBEDTLS_SSL_HASH_XXX
+ */
+unsigned char mbedtls_ssl_hash_from_md_alg( int md )
+{
+ switch( md )
+ {
+#if defined(MBEDTLS_MD5_C)
+ case MBEDTLS_MD_MD5:
+ return( MBEDTLS_SSL_HASH_MD5 );
+#endif
+#if defined(MBEDTLS_SHA1_C)
+ case MBEDTLS_MD_SHA1:
+ return( MBEDTLS_SSL_HASH_SHA1 );
+#endif
+#if defined(MBEDTLS_SHA256_C)
+ case MBEDTLS_MD_SHA224:
+ return( MBEDTLS_SSL_HASH_SHA224 );
+ case MBEDTLS_MD_SHA256:
+ return( MBEDTLS_SSL_HASH_SHA256 );
+#endif
+#if defined(MBEDTLS_SHA512_C)
+ case MBEDTLS_MD_SHA384:
+ return( MBEDTLS_SSL_HASH_SHA384 );
+ case MBEDTLS_MD_SHA512:
+ return( MBEDTLS_SSL_HASH_SHA512 );
+#endif
+ default:
+ return( MBEDTLS_SSL_HASH_NONE );
+ }
+}
+
#if defined(MBEDTLS_ECP_C)
/*
- * Check is a curve proposed by the peer is in our list.
+ * Check if a curve proposed by the peer is in our list.
* Return 0 if we're willing to use it, -1 otherwise.
*/
int mbedtls_ssl_check_curve( const mbedtls_ssl_context *ssl, mbedtls_ecp_group_id grp_id )
@@ -6839,6 +6871,27 @@
}
#endif /* MBEDTLS_ECP_C */
+#if defined(MBEDTLS_KEY_EXCHANGE__SOME__SIGNATURE_ENABLED)
+/*
+ * Check if a hash proposed by the peer is in our list.
+ * Return 0 if we're willing to use it, -1 otherwise.
+ */
+int mbedtls_ssl_check_sig_hash( const mbedtls_ssl_context *ssl,
+ mbedtls_md_type_t md )
+{
+ const int *cur;
+
+ if( ssl->conf->sig_hashes == NULL )
+ return( -1 );
+
+ for( cur = ssl->conf->sig_hashes; *cur != MBEDTLS_MD_NONE; cur++ )
+ if( *cur == (int) md )
+ return( 0 );
+
+ return( -1 );
+}
+#endif /* MBEDTLS_KEY_EXCHANGE__SOME__SIGNATURE_ENABLED */
+
#if defined(MBEDTLS_X509_CRT_PARSE_C)
int mbedtls_ssl_check_cert_usage( const mbedtls_x509_crt *cert,
const mbedtls_ssl_ciphersuite_t *ciphersuite,