diff options
Diffstat (limited to 'lib/ssh/src/ssh_transport.erl')
| -rw-r--r-- | lib/ssh/src/ssh_transport.erl | 92 |
1 files changed, 44 insertions, 48 deletions
diff --git a/lib/ssh/src/ssh_transport.erl b/lib/ssh/src/ssh_transport.erl index d622ec27fc..d61fc76c0a 100644 --- a/lib/ssh/src/ssh_transport.erl +++ b/lib/ssh/src/ssh_transport.erl @@ -441,19 +441,29 @@ 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 - {G, P} = dh_gex_group(Min, NBits, Max, proplists:get_value(dh_gex_groups,Opts)), - {Public, Private} = generate_key(dh, [P,G]), - {SshPacket, Ssh} = - ssh_packet(#ssh_msg_kex_dh_gex_group{p = P, g = G}, Ssh0), - {ok, SshPacket, - Ssh#ssh{keyex_key = {{Private, Public}, {G, P}}, - keyex_info = {Min, Max, NBits} - }}; + {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 + {ok, {_Sz, {G,P}}} -> + {Public, Private} = generate_key(dh, [P,G]), + {SshPacket, Ssh} = + ssh_packet(#ssh_msg_kex_dh_gex_group{p = P, g = G}, Ssh0), + {ok, SshPacket, + Ssh#ssh{keyex_key = {{Private, Public}, {G, P}}, + keyex_info = {Min, Max, NBits} + }}; + {error,_} -> + throw(#ssh_msg_disconnect{ + code = ?SSH_DISCONNECT_PROTOCOL_ERROR, + description = "No possible diffie-hellman-group-exchange group found", + language = ""}) + end; + handle_kex_dh_gex_request(_, _) -> throw({{error,bad_ssh_msg_kex_dh_gex_request}, #ssh_msg_disconnect{ @@ -462,6 +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]), @@ -1482,44 +1512,10 @@ peer_name({Host, _}) -> %% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -dh_group('diffie-hellman-group1-sha1') -> element(2, ?dh_group1); -dh_group('diffie-hellman-group14-sha1') -> element(2, ?dh_group14). - -dh_gex_default_groups() -> ?dh_default_groups. - - -dh_gex_group(Min, N, Max, undefined) -> - dh_gex_group(Min, N, Max, dh_gex_default_groups()); -dh_gex_group(Min, N, Max, Groups) -> - %% First try to find an exact match. If not an exact match, select the largest possible. - {_Size,Group} = - lists:foldl( - fun(_, {I,G}) when I==N -> - %% If we have an exact match already: use that one - {I,G}; - ({I,G}, _) when I==N -> - %% If we now found an exact match: use that very one - {I,G}; - ({I,G}, {Imax,_Gmax}) when Min=<I,I=<Max, % a) {I,G} fullfills the requirements - I>Imax -> % b) {I,G} is larger than current max - %% A group within the limits and better than the one we have - {I,G}; - (_, IGmax) -> - %% Keep the one we have - IGmax - end, {-1,undefined}, Groups), - - case Group of - undefined -> - throw(#ssh_msg_disconnect{ - code = ?SSH_DISCONNECT_PROTOCOL_ERROR, - description = "No possible diffie-hellman-group-exchange group found", - language = ""}); - _ -> - Group - end. - +dh_group('diffie-hellman-group1-sha1') -> ?dh_group1; +dh_group('diffie-hellman-group14-sha1') -> ?dh_group14. +%%%---------------------------------------------------------------- generate_key(Algorithm, Args) -> {Public,Private} = crypto:generate_key(Algorithm, Args), {crypto:bytes_to_integer(Public), crypto:bytes_to_integer(Private)}. |