ports/lang/erlang-runtime17/files/patch-lib_ssl_src_ssl__connection.erl
2017-12-16 17:33:32 +00:00

30 lines
1.4 KiB
Erlang

--- lib/ssl/src/ssl_connection.erl.orig 2015-03-31 12:32:52.000000000 +0000
+++ lib/ssl/src/ssl_connection.erl 2017-12-14 13:13:46.570861000 +0000
@@ -1135,8 +1135,25 @@
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},