Create API for mbedtls_ssl_conf_sig_hashes().

Not implemented yet.

include/mbedtls/ssl.h

@@ -70,6 +70,12 @@
 #define MBEDTLS_KEY_EXCHANGE__SOME__ECDHE_ENABLED
 #endif
 
+#if defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED) ||                       \
+    defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) ||                     \
+    defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
+#define MBEDTLS_KEY_EXCHANGE__SOME__SIGNATURE_ENABLED
+#endif
+
 /*
  * SSL Error codes
  */
@@ -529,12 +535,16 @@ struct mbedtls_ssl_config
 #endif /* MBEDTLS_SSL_SESSION_TICKETS && MBEDTLS_SSL_SRV_C */
 
 #if defined(MBEDTLS_X509_CRT_PARSE_C)
-    const mbedtls_x509_crt_profile *cert_profile; /*!< verification profile       */
+    const mbedtls_x509_crt_profile *cert_profile; /*!< verification profile */
     mbedtls_ssl_key_cert *key_cert; /*!< own certificate/key pair(s)        */
     mbedtls_x509_crt *ca_chain;     /*!< trusted CAs                        */
     mbedtls_x509_crl *ca_crl;       /*!< trusted CAs CRLs                   */
 #endif /* MBEDTLS_X509_CRT_PARSE_C */
 
+#if defined(MBEDTLS_KEY_EXCHANGE__SOME__SIGNATURE_ENABLED)
+    const int *sig_hashes;          /*!< allowed signature hashes           */
+#endif
+
 #if defined(MBEDTLS_ECP_C)
     const mbedtls_ecp_group_id *curve_list; /*!< allowed curves             */
 #endif
@@ -1527,13 +1537,40 @@ void mbedtls_ssl_conf_dhm_min_bitlen( mbedtls_ssl_config *conf,
  *                 controlled by \c mbedtls_ssl_conf_curves() but for CA_int
  *                 and CA_root it's \c mbedtls_ssl_conf_cert_profile().
  *
+ * \note           This list should be ordered by decreasing preference
+ *                 (preferred curve first).
+ *
  * \param conf     SSL configuration
  * \param curves   Ordered list of allowed curves,
  *                 terminated by MBEDTLS_ECP_DP_NONE.
  */
-void mbedtls_ssl_conf_curves( mbedtls_ssl_config *conf, const mbedtls_ecp_group_id *curves );
+void mbedtls_ssl_conf_curves( mbedtls_ssl_config *conf,
+                              const mbedtls_ecp_group_id *curves );
 #endif /* MBEDTLS_ECP_C */
 
+#if defined(MBEDTLS_KEY_EXCHANGE__SOME__SIGNATURE_ENABLED)
+/**
+ * \brief          Set the allowed hashes for signatures during the handshake.
+ *                 (Default: all available hashes.)
+ *
+ * \note           This only affects which hashes are offered and can be used
+ *                 for signatures during the handshake. Hashes for message
+ *                 authentication and the TLS PRF are controlled by the
+ *                 ciphersuite, see \c mbedtls_ssl_conf_ciphersuites(). Hashes
+ *                 used for certificate signature are controlled by the
+ *                 verification profile, see \c mbedtls_ssl_conf_cert_profile().
+ *
+ * \note           This list should be ordered by decreasing preference
+ *                 (preferred hash first).
+ *
+ * \param conf     SSL configuration
+ * \param hashes   Ordered list of allowed signature hashes,
+ *                 terminated by \c MBEDTLS_MD_NONE.
+ */
+void mbedtls_ssl_conf_sig_hashes( mbedtls_ssl_config *conf,
+                                  const int *hashes );
+#endif /* MBEDTLS_KEY_EXCHANGE__SOME__SIGNATURE_ENABLED */
+
 #if defined(MBEDTLS_X509_CRT_PARSE_C)
 /**
  * \brief          Set hostname for ServerName TLS extension

library/ssl_cli.c

@@ -1836,9 +1836,7 @@ static int ssl_write_encrypted_pms( mbedtls_ssl_context *ssl,
           MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED */
 
 #if defined(MBEDTLS_SSL_PROTO_TLS1_2)
-#if defined(MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED) ||                       \
+#if defined(MBEDTLS_KEY_EXCHANGE__SOME__SIGNATURE_ENABLED)
-    defined(MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED) ||                     \
-    defined(MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED)
 static int ssl_parse_signature_algorithm( mbedtls_ssl_context *ssl,
                                           unsigned char **p,
                                           unsigned char *end,
@@ -1884,12 +1882,9 @@ static int ssl_parse_signature_algorithm( mbedtls_ssl_context *ssl,
 
     return( 0 );
 }
-#endif /* MBEDTLS_KEY_EXCHANGE_DHE_RSA_ENABLED ||
+#endif /* MBEDTLS_KEY_EXCHANGE__SOME__SIGNATURE_ENABLED */
-          MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED ||
-          MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED */
 #endif /* MBEDTLS_SSL_PROTO_TLS1_2 */
 
-
 #if defined(MBEDTLS_KEY_EXCHANGE_ECDH_RSA_ENABLED) || \
     defined(MBEDTLS_KEY_EXCHANGE_ECDH_ECDSA_ENABLED)
 static int ssl_get_ecdh_params_from_cert( mbedtls_ssl_context *ssl )

library/ssl_tls.c

@@ -5478,6 +5478,17 @@ void mbedtls_ssl_conf_dhm_min_bitlen( mbedtls_ssl_config *conf,
 }
 #endif /* MBEDTLS_DHM_C && MBEDTLS_SSL_CLI_C */
 
+#if defined(MBEDTLS_KEY_EXCHANGE__SOME__SIGNATURE_ENABLED)
+/*
+ * Set allowed/preferred hashes for handshake signatures
+ */
+void mbedtls_ssl_conf_sig_hashes( mbedtls_ssl_config *conf,
+                                  const int *hashes )
+{
+    conf->sig_hashes = hashes;
+}
+#endif
+
 #if defined(MBEDTLS_ECP_C)
 /*
  * Set the allowed elliptic curves
@@ -6665,8 +6676,12 @@ int mbedtls_ssl_config_defaults( mbedtls_ssl_config *conf,
     conf->cbc_record_splitting = MBEDTLS_SSL_CBC_RECORD_SPLITTING_ENABLED;
 #endif
 
+#if defined(MBEDTLS_KEY_EXCHANGE__SOME__SIGNATURE_ENABLED)
+    conf->sig_hashes = mbedtls_md_list();
+#endif
+
 #if defined(MBEDTLS_ECP_C)
-    conf->curve_list = mbedtls_ecp_grp_id_list( );
+    conf->curve_list = mbedtls_ecp_grp_id_list();
 #endif
 
 #if defined(MBEDTLS_SSL_DTLS_HELLO_VERIFY) && defined(MBEDTLS_SSL_SRV_C)