/* Go through the hello extensions in |ss->ssl3.hs.remoteExtensions|.
* For each one, find the extension handler in the table, and
* if present, invoke that handler.
* Servers ignore any extensions with unknown extension types.
* Clients reject any extensions with unadvertised extension types
*
* In TLS >= 1.3, the client checks that extensions appear in the
* right phase.
*/
SECStatus
ssl3_HandleParsedExtensions(sslSocket *ss, SSLHandshakeType message)
{
const ssl3ExtensionHandler *handlers;
/* HelloRetryRequest doesn't set ss->version. It might be safe to
* do so, but we weren't entirely sure. TODO([email protected]). */
PRBool isTLS13 = (ss->version >= SSL_LIBRARY_VERSION_TLS_1_3) ||
(message == ssl_hs_hello_retry_request);
/* The following messages can include extensions that were not included in
* the original ClientHello. */
PRBool allowNotOffered = (message == ssl_hs_client_hello) ||
(message == ssl_hs_certificate_request) ||
(message == ssl_hs_new_session_ticket);
PRCList *cursor;
switch (message) {
case ssl_hs_client_hello:
handlers = clientHelloHandlers;
break;
case ssl_hs_new_session_ticket:
PORT_Assert(ss->version >= SSL_LIBRARY_VERSION_TLS_1_3);
handlers = newSessionTicketHandlers;
break;
case ssl_hs_hello_retry_request:
handlers = helloRetryRequestHandlers;
break;
case ssl_hs_encrypted_extensions:
PORT_Assert(ss->version >= SSL_LIBRARY_VERSION_TLS_1_3);
/* fall through */
case ssl_hs_server_hello:
if (ss->version > SSL_LIBRARY_VERSION_3_0) {
handlers = serverHelloHandlersTLS;
} else {
handlers = serverHelloHandlersSSL3;
}
break;
case ssl_hs_certificate:
PORT_Assert(!ss->sec.isServer);
handlers = serverCertificateHandlers;
break;
case ssl_hs_certificate_request:
PORT_Assert(!ss->sec.isServer);
handlers = certificateRequestHandlers;
break;
default:
PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
PORT_Assert(0);
return SECFailure;
}
for (cursor = PR_NEXT_LINK(&ss->ssl3.hs.remoteExtensions);
cursor != &ss->ssl3.hs.remoteExtensions;
cursor = PR_NEXT_LINK(cursor)) {
TLSExtension *extension = (TLSExtension *)cursor;
SECStatus rv;
/* Check whether the server sent an extension which was not advertised
* in the ClientHello.
*
* Note that a TLS 1.3 server should check if CertificateRequest
* extensions were sent. But the extensions used for CertificateRequest
* do not have any response, so we rely on
* ssl3_ExtensionAdvertised to return false on the server. That
* results in the server only rejecting any extension. */
if (!allowNotOffered && (extension->type != ssl_tls13_cookie_xtn) &&
!ssl3_ExtensionAdvertised(ss, extension->type)) {
(void)SSL3_SendAlert(ss, alert_fatal, unsupported_extension);
PORT_SetError(SSL_ERROR_RX_UNEXPECTED_EXTENSION);
return SECFailure;
}
/* Check that this is a legal extension in TLS 1.3 */
if (isTLS13 &&
!ssl_FindCustomExtensionHooks(ss, extension->type)) {
switch (tls13_ExtensionStatus(extension->type, message)) {
case tls13_extension_allowed:
break;
case tls13_extension_unknown:
if (allowNotOffered) {
continue; /* Skip over unknown extensions. */
}
/* Fall through. */
case tls13_extension_disallowed:
SSL_TRC(3, ("%d: TLS13: unexpected extension %d in message %d",
SSL_GETPID(), extension, message));
tls13_FatalError(ss, SSL_ERROR_EXTENSION_DISALLOWED_FOR_VERSION,
unsupported_extension);
return SECFailure;
}
}
/* Special check for this being the last extension if it's
* PreSharedKey */
if (ss->sec.isServer && isTLS13 &&
(extension->type == ssl_tls13_pre_shared_key_xtn) &&
(PR_NEXT_LINK(cursor) != &ss->ssl3.hs.remoteExtensions)) {
tls13_FatalError(ss,
SSL_ERROR_RX_MALFORMED_CLIENT_HELLO,
illegal_parameter);
return SECFailure;
}
rv = ssl_CallExtensionHandler(ss, message, extension, handlers);
if (rv != SECSuccess) {
return SECFailure;
}
}
return SECSuccess;
}
/* Go through the hello extensions in |ss->ssl3.hs.remoteExtensions|.
* For each one, find the extension handler in the table, and
* if present, invoke that handler.
* Servers ignore any extensions with unknown extension types.
* Clients reject any extensions with unadvertised extension types
*
* In TLS >= 1.3, the client checks that extensions appear in the
* right phase.
*/
SECStatus
ssl3_HandleParsedExtensions(sslSocket *ss,
SSL3HandshakeType handshakeMessage)
{
const ssl3ExtensionHandler *handlers;
PRBool isTLS13 = ss->version >= SSL_LIBRARY_VERSION_TLS_1_3;
PRCList *cursor;
switch (handshakeMessage) {
case client_hello:
handlers = clientHelloHandlers;
break;
case new_session_ticket:
PORT_Assert(ss->version >= SSL_LIBRARY_VERSION_TLS_1_3);
handlers = newSessionTicketHandlers;
break;
case hello_retry_request:
handlers = helloRetryRequestHandlers;
break;
case encrypted_extensions:
PORT_Assert(ss->version >= SSL_LIBRARY_VERSION_TLS_1_3);
/* fall through */
case server_hello:
if (ss->version > SSL_LIBRARY_VERSION_3_0) {
handlers = serverHelloHandlersTLS;
} else {
handlers = serverHelloHandlersSSL3;
}
break;
case certificate:
PORT_Assert(!ss->sec.isServer);
handlers = serverCertificateHandlers;
break;
default:
PORT_SetError(SEC_ERROR_LIBRARY_FAILURE);
PORT_Assert(0);
return SECFailure;
}
for (cursor = PR_NEXT_LINK(&ss->ssl3.hs.remoteExtensions);
cursor != &ss->ssl3.hs.remoteExtensions;
cursor = PR_NEXT_LINK(cursor)) {
TLSExtension *extension = (TLSExtension *)cursor;
const ssl3ExtensionHandler *handler;
/* Check whether the server sent an extension which was not advertised
* in the ClientHello */
if (!ss->sec.isServer &&
!ssl3_ClientExtensionAdvertised(ss, extension->type) &&
(handshakeMessage != new_session_ticket) &&
(extension->type != ssl_tls13_cookie_xtn)) {
(void)SSL3_SendAlert(ss, alert_fatal, unsupported_extension);
PORT_SetError(SSL_ERROR_RX_UNEXPECTED_EXTENSION);
return SECFailure;
}
/* Check that this is a legal extension in TLS 1.3 */
if (isTLS13 && !tls13_ExtensionAllowed(extension->type, handshakeMessage)) {
if (handshakeMessage == client_hello) {
/* Skip extensions not used in TLS 1.3 */
continue;
}
tls13_FatalError(ss, SSL_ERROR_EXTENSION_DISALLOWED_FOR_VERSION,
unsupported_extension);
return SECFailure;
}
/* Special check for this being the last extension if it's
* PreSharedKey */
if (ss->sec.isServer && isTLS13 &&
(extension->type == ssl_tls13_pre_shared_key_xtn) &&
(PR_NEXT_LINK(cursor) != &ss->ssl3.hs.remoteExtensions)) {
tls13_FatalError(ss,
SSL_ERROR_RX_MALFORMED_CLIENT_HELLO,
illegal_parameter);
return SECFailure;
}
/* find extension_type in table of Hello Extension Handlers */
for (handler = handlers; handler->ex_type >= 0; handler++) {
/* if found, call this handler */
if (handler->ex_type == extension->type) {
SECStatus rv;
rv = (*handler->ex_handler)(ss, &ss->xtnData,
(PRUint16)extension->type,
&extension->data);
if (rv != SECSuccess) {
if (!ss->ssl3.fatalAlertSent) {
/* send a generic alert if the handler didn't already */
(void)SSL3_SendAlert(ss, alert_fatal, handshake_failure);
}
return SECFailure;
}
}
}
}
return SECSuccess;
}
