OpenSSL: Add openssl_ecdh_curves parameter

Some versions of OpenSSL need server support for ECDH to be explicitly
enabled, so provide a new parameter for doing so and all
SSL_{,CTX_}set_ecdh_auto() for versions that need it to enable automatic
selection.

Signed-off-by: Hristo Venev <hristo@venev.name>

src/crypto/tls.h

@@ -144,6 +144,8 @@ struct tls_config {
  * @cert_id: the certificate's id when using engine
  * @ca_cert_id: the CA certificate's id when using engine
  * @openssl_ciphers: OpenSSL cipher configuration
+ * @openssl_ecdh_curves: OpenSSL ECDH curve configuration. %NULL for auto if
+ *	supported, empty string to disable, or a colon-separated curve list.
  * @flags: Parameter options (TLS_CONN_*)
  * @ocsp_stapling_response: DER encoded file with cached OCSP stapling response
  *	or %NULL if OCSP is not enabled
@@ -187,6 +189,7 @@ struct tls_connection_params {
 	const char *cert_id;
 	const char *ca_cert_id;
 	const char *openssl_ciphers;
+	const char *openssl_ecdh_curves;
 
 	unsigned int flags;
 	const char *ocsp_stapling_response;

src/crypto/tls_gnutls.c

@@ -461,6 +461,12 @@ int tls_connection_set_params(void *tls_ctx, struct tls_connection *conn,
 		}
 	}
 
+	if (params->openssl_ecdh_curves) {
+		wpa_printf(MSG_INFO,
+			   "GnuTLS: openssl_ecdh_curves not supported");
+		return -1;
+	}
+
 	/* TODO: gnutls_certificate_set_verify_flags(xcred, flags);
 	 * to force peer validation(?) */
 

src/crypto/tls_internal.c

@@ -248,6 +248,12 @@ int tls_connection_set_params(void *tls_ctx, struct tls_connection *conn,
 		return -1;
 	}
 
+	if (params->openssl_ecdh_curves) {
+		wpa_printf(MSG_INFO, "TLS: openssl_ecdh_curves not supported");
+		tlsv1_cred_free(cred);
+		return -1;
+	}
+
 	if (tlsv1_set_ca_cert(cred, params->ca_cert,
 			      params->ca_cert_blob, params->ca_cert_blob_len,
 			      params->ca_path)) {

src/crypto/tls_openssl.c

@@ -4505,6 +4505,40 @@ int tls_connection_set_params(void *tls_ctx, struct tls_connection *conn,
 		return -1;
 	}
 
+	if (!params->openssl_ecdh_curves) {
+#ifndef OPENSSL_IS_BORINGSSL
+#ifndef OPENSSL_NO_EC
+#if (OPENSSL_VERSION_NUMBER >= 0x10002000L) && \
+	(OPENSSL_VERSION_NUMBER < 0x10100000L)
+		if (SSL_set_ecdh_auto(conn->ssl, 1) != 1) {
+			wpa_printf(MSG_INFO,
+				   "OpenSSL: Failed to set ECDH curves to auto");
+			return -1;
+		}
+#endif /* >= 1.0.2 && < 1.1.0 */
+#endif /* OPENSSL_NO_EC */
+#endif /* OPENSSL_IS_BORINGSSL */
+	} else if (params->openssl_ecdh_curves[0]) {
+#if defined(OPENSSL_IS_BORINGSSL) || (OPENSSL_VERSION_NUMBER < 0x10002000L)
+		wpa_printf(MSG_INFO,
+			"OpenSSL: ECDH configuration nnot supported");
+		return -1;
+#else /* OPENSSL_IS_BORINGSSL || < 1.0.2 */
+#ifndef OPENSSL_NO_EC
+		if (SSL_set1_curves_list(conn->ssl,
+					 params->openssl_ecdh_curves) != 1) {
+			wpa_printf(MSG_INFO,
+				   "OpenSSL: Failed to set ECDH curves '%s'",
+				   params->openssl_ecdh_curves);
+			return -1;
+		}
+#else /* OPENSSL_NO_EC */
+		wpa_printf(MSG_INFO, "OpenSSL: ECDH not supported");
+		return -1;
+#endif /* OPENSSL_NO_EC */
+#endif /* OPENSSL_IS_BORINGSSL */
+	}
+
 	if (tls_set_conn_flags(conn, params->flags,
 			       params->openssl_ciphers) < 0)
 		return -1;
@@ -4571,6 +4605,41 @@ int tls_global_set_params(void *tls_ctx,
 		return -1;
 	}
 
+	if (!params->openssl_ecdh_curves) {
+#ifndef OPENSSL_IS_BORINGSSL
+#ifndef OPENSSL_NO_EC
+#if (OPENSSL_VERSION_NUMBER >= 0x10002000L) && \
+	(OPENSSL_VERSION_NUMBER < 0x10100000L)
+		if (SSL_CTX_set_ecdh_auto(ssl_ctx, 1) != 1) {
+			wpa_printf(MSG_INFO,
+				   "OpenSSL: Failed to set ECDH curves to auto");
+			return -1;
+		}
+#endif /* >= 1.0.2 && < 1.1.0 */
+#endif /* OPENSSL_NO_EC */
+#endif /* OPENSSL_IS_BORINGSSL */
+	} else if (params->openssl_ecdh_curves[0]) {
+#if defined(OPENSSL_IS_BORINGSSL) || (OPENSSL_VERSION_NUMBER < 0x10002000L)
+		wpa_printf(MSG_INFO,
+			"OpenSSL: ECDH configuration nnot supported");
+		return -1;
+#else /* OPENSSL_IS_BORINGSSL || < 1.0.2 */
+#ifndef OPENSSL_NO_EC
+		if (SSL_CTX_set1_curves_list(ssl_ctx,
+					     params->openssl_ecdh_curves) !=
+		    1) {
+			wpa_printf(MSG_INFO,
+				   "OpenSSL: Failed to set ECDH curves '%s'",
+				   params->openssl_ecdh_curves);
+			return -1;
+		}
+#else /* OPENSSL_NO_EC */
+		wpa_printf(MSG_INFO, "OpenSSL: ECDH not supported");
+		return -1;
+#endif /* OPENSSL_NO_EC */
+#endif /* OPENSSL_IS_BORINGSSL */
+	}
+
 #ifdef SSL_OP_NO_TICKET
 	if (params->flags & TLS_CONN_DISABLE_SESSION_TICKET)
 		SSL_CTX_set_options(ssl_ctx, SSL_OP_NO_TICKET);

src/crypto/tls_wolfssl.c

@@ -1524,6 +1524,12 @@ int tls_global_set_params(void *tls_ctx,
 		return -1;
 	}
 
+	if (params->openssl_ecdh_curves) {
+		wpa_printf(MSG_INFO,
+			   "wolfSSL: openssl_ecdh_curves not supported");
+		return -1;
+	}
+
 #ifdef HAVE_SESSION_TICKET
 	/* Session ticket is off by default - can't disable once on. */
 	if (!(params->flags & TLS_CONN_DISABLE_SESSION_TICKET))