If we're negotiating a datagram protocol, allow a hello verify

message. Add client-side hello verify handling.

1 files changed, 20 insertions, 2 deletions

diff --git a/src/tls/tls_client.cpp b/src/tls/tls_client.cpp
index 46e5296e2..e72dcbc8f 100644
--- a/src/tls/tls_client.cpp
+++ b/src/tls/tls_client.cpp
@@ -71,6 +71,8 @@ void Client::initiate_handshake(bool force_full_renegotiation,
    if(!m_writer.record_version_set())
       m_writer.set_version(m_state->handshake_io().initial_record_version());
 
+   if(m_state->version().is_datagram_protocol())
+      m_state->set_expected_next(HELLO_VERIFY_REQUEST);
    m_state->set_expected_next(SERVER_HELLO);
 
    m_state->client_npn_cb = next_protocol;
@@ -157,10 +159,26 @@ void Client::process_handshake_msg(Handshake_Type type,
 
    m_state->confirm_transition_to(type);
 
-   if(type != HANDSHAKE_CCS && type != FINISHED)
+   if(type != HANDSHAKE_CCS && type != FINISHED && type != HELLO_VERIFY_REQUEST)
       m_state->hash.update(m_state->handshake_io().format(contents, type));
 
-   if(type == SERVER_HELLO)
+   if(type == HELLO_VERIFY_REQUEST)
+      {
+      m_state->set_expected_next(SERVER_HELLO);
+      m_state->set_expected_next(HELLO_VERIFY_REQUEST); // might get it again
+
+      Hello_Verify_Request hello_verify_request(contents);
+
+      std::unique_ptr<Client_Hello> client_hello_w_cookie(
+         new Client_Hello(m_state->handshake_io(),
+                          m_state->hash,
+                          *m_state->client_hello,
+                          hello_verify_request));
+
+      delete m_state->client_hello;
+      m_state->client_hello = client_hello_w_cookie.release();
+      }
+   else if(type == SERVER_HELLO)
       {
       m_state->server_hello = new Server_Hello(contents);