diff options
Diffstat (limited to 'src/lib/tls/tls_server.cpp')
| -rw-r--r-- | src/lib/tls/tls_server.cpp | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/src/lib/tls/tls_server.cpp b/src/lib/tls/tls_server.cpp index 6fe266989..71e8d1d14 100644 --- a/src/lib/tls/tls_server.cpp +++ b/src/lib/tls/tls_server.cpp @@ -291,10 +291,13 @@ void Server::process_handshake_msg(const Handshake_State* active_state, state.client_hello(new Client_Hello(contents, type)); - Protocol_Version client_version = state.client_hello()->version(); + const Protocol_Version client_version = state.client_hello()->version(); Protocol_Version negotiated_version; + const Protocol_Version latest_supported = + m_policy.latest_supported_version(client_version.is_datagram_protocol()); + if((initial_handshake && client_version.known_version()) || (!initial_handshake && client_version == active_state->version())) { @@ -329,10 +332,10 @@ void Server::process_handshake_msg(const Handshake_State* active_state, else { /* - New negotiation using a version we don't know. Offer - them the best we currently know. + New negotiation using a version we don't know. Offer them the + best we currently know and support */ - negotiated_version = client_version.best_known_match(); + negotiated_version = latest_supported; } if(!m_policy.acceptable_protocol_version(negotiated_version)) @@ -342,6 +345,13 @@ void Server::process_handshake_msg(const Handshake_State* active_state, " is unacceptable by policy"); } + if(state.client_hello()->sent_fallback_scsv()) + { + if(latest_supported > client_version) + throw TLS_Exception(Alert::INAPPROPRIATE_FALLBACK, + "Client signalled fallback SCSV, possible attack"); + } + if(!initial_handshake && state.client_hello()->next_protocol_notification()) throw TLS_Exception(Alert::HANDSHAKE_FAILURE, "Client included NPN extension for renegotiation"); |