diff options
Diffstat (limited to 'lib/ssh/src/ssh_transport.erl')
| -rw-r--r-- | lib/ssh/src/ssh_transport.erl | 29 |
1 files changed, 25 insertions, 4 deletions
diff --git a/lib/ssh/src/ssh_transport.erl b/lib/ssh/src/ssh_transport.erl index 35bfadb1df..d61fc76c0a 100644 --- a/lib/ssh/src/ssh_transport.erl +++ b/lib/ssh/src/ssh_transport.erl @@ -441,13 +441,14 @@ handle_kexdh_reply(#ssh_msg_kexdh_reply{public_host_key = PeerPubHostKey, %%% %%% diffie-hellman-group-exchange-sha1 %%% -handle_kex_dh_gex_request(#ssh_msg_kex_dh_gex_request{min = Min, +handle_kex_dh_gex_request(#ssh_msg_kex_dh_gex_request{min = Min0, n = NBits, - max = Max}, - Ssh0=#ssh{opts=Opts}) when Min=<NBits, NBits=<Max -> + max = Max0}, + Ssh0=#ssh{opts=Opts}) when Min0=<NBits, NBits=<Max0 -> %% server + {Min, Max} = adjust_gex_min_max(Min0, Max0, Opts), case public_key:dh_gex_group(Min, NBits, Max, - proplists:get_value(dh_gex_groups,Opts)) of + proplists:get_value(dh_gex_groups,Opts)) of {ok, {_Sz, {G,P}}} -> {Public, Private} = generate_key(dh, [P,G]), {SshPacket, Ssh} = @@ -471,6 +472,26 @@ handle_kex_dh_gex_request(_, _) -> language = ""} }). + +adjust_gex_min_max(Min0, Max0, Opts) -> + case proplists:get_value(dh_gex_limits, Opts) of + undefined -> + {Min0, Max0}; + {Min1, Max1} -> + Min2 = max(Min0, Min1), + Max2 = min(Max0, Max1), + if + Min2 =< Max2 -> + {Min2, Max2}; + Max2 < Min2 -> + throw(#ssh_msg_disconnect{ + code = ?SSH_DISCONNECT_PROTOCOL_ERROR, + description = "No possible diffie-hellman-group-exchange group possible", + language = ""}) + end + end. + + handle_kex_dh_gex_group(#ssh_msg_kex_dh_gex_group{p = P, g = G}, Ssh0) -> %% client {Public, Private} = generate_key(dh, [P,G]), |