diff options
Diffstat (limited to 'lib/ssl/src/ssl_connection.erl')
| -rw-r--r-- | lib/ssl/src/ssl_connection.erl | 21 |
1 files changed, 19 insertions, 2 deletions
diff --git a/lib/ssl/src/ssl_connection.erl b/lib/ssl/src/ssl_connection.erl index b031d3d47b..b33ce63c32 100644 --- a/lib/ssl/src/ssl_connection.erl +++ b/lib/ssl/src/ssl_connection.erl @@ -1367,8 +1367,25 @@ server_certify_and_key_exchange(State0, Connection) -> request_client_cert(State2, Connection). certify_client_key_exchange(#encrypted_premaster_secret{premaster_secret= EncPMS}, - #state{private_key = Key} = State, Connection) -> - PremasterSecret = ssl_handshake:premaster_secret(EncPMS, Key), + #state{private_key = Key, client_hello_version = {Major, Minor} = Version} = State, Connection) -> + + %% Countermeasure for Bleichenbacher attack always provide some kind of premaster secret + %% and fail handshake later.RFC 5246 section 7.4.7.1. + PremasterSecret = + try ssl_handshake:premaster_secret(EncPMS, Key) of + Secret when erlang:byte_size(Secret) == ?NUM_OF_PREMASTERSECRET_BYTES -> + case Secret of + <<?BYTE(Major), ?BYTE(Minor), _/binary>> -> %% Correct + Secret; + <<?BYTE(_), ?BYTE(_), Rest/binary>> -> %% Version mismatch + <<?BYTE(Major), ?BYTE(Minor), Rest/binary>> + end; + _ -> %% erlang:byte_size(Secret) =/= ?NUM_OF_PREMASTERSECRET_BYTES + make_premaster_secret(Version, rsa) + catch + #alert{description = ?DECRYPT_ERROR} -> + make_premaster_secret(Version, rsa) + end, calculate_master_secret(PremasterSecret, State, Connection, certify, cipher); certify_client_key_exchange(#client_diffie_hellman_public{dh_public = ClientPublicDhKey}, |