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authorHans Nilsson <[email protected]>2017-04-10 16:25:06 +0200
committerHans Nilsson <[email protected]>2017-04-26 12:13:01 +0200
commit29d7533c715f972ee996382c2c45cc0c055e10d2 (patch)
treeb370920e82c28335cb601d997920d41ea6cd76cd /lib/ssh/src
parentc0d2e134f90ddd3fd2f5b0f9a94a5b0d55c93416 (diff)
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ssh: Implement ext-info extension. draft-ietf-curdle-ssh-ext-info
This is only a draft extension, but it is quite stable and already supported by some implementations. OpenSSH has had it for some year now.
Diffstat (limited to 'lib/ssh/src')
-rw-r--r--lib/ssh/src/ssh.hrl7
-rw-r--r--lib/ssh/src/ssh_connection_handler.erl142
-rw-r--r--lib/ssh/src/ssh_dbg.erl5
-rw-r--r--lib/ssh/src/ssh_message.erl33
-rw-r--r--lib/ssh/src/ssh_options.erl22
-rw-r--r--lib/ssh/src/ssh_transport.erl221
-rw-r--r--lib/ssh/src/ssh_transport.hrl15
7 files changed, 334 insertions, 111 deletions
diff --git a/lib/ssh/src/ssh.hrl b/lib/ssh/src/ssh.hrl
index c7ed11895c..1a95bb27e7 100644
--- a/lib/ssh/src/ssh.hrl
+++ b/lib/ssh/src/ssh.hrl
@@ -145,6 +145,9 @@
c_keyinit, %% binary payload of kexinit packet
s_keyinit, %% binary payload of kexinit packet
+ send_ext_info, %% May send ext-info to peer
+ recv_ext_info, %% Expect ext-info from peer
+
algorithms, %% #alg{}
kex, %% key exchange algorithm
@@ -216,7 +219,9 @@
compress,
decompress,
c_lng,
- s_lng
+ s_lng,
+ send_ext_info,
+ recv_ext_info
}).
-record(ssh_key,
diff --git a/lib/ssh/src/ssh_connection_handler.erl b/lib/ssh/src/ssh_connection_handler.erl
index 84bb7dc23f..0ff7c9b3a1 100644
--- a/lib/ssh/src/ssh_connection_handler.erl
+++ b/lib/ssh/src/ssh_connection_handler.erl
@@ -453,7 +453,9 @@ init_ssh_record(Role, _Socket, PeerAddr, Opts) ->
PeerName = case ?GET_INTERNAL_OPT(host, Opts) of
PeerIP when is_tuple(PeerIP) ->
inet_parse:ntoa(PeerIP);
- PeerName0 ->
+ PeerName0 when is_atom(PeerName0) ->
+ atom_to_list(PeerName0);
+ PeerName0 when is_list(PeerName0) ->
PeerName0
end,
S0#ssh{c_vsn = Vsn,
@@ -493,6 +495,7 @@ init_ssh_record(Role, _Socket, PeerAddr, Opts) ->
| {key_exchange_dh_gex_init, server, renegotiate_flag()}
| {key_exchange_dh_gex_reply, client, renegotiate_flag()}
| {new_keys, role()}
+ | {ext_info, role(), renegotiate_flag()}
| {service_request, role()}
| {userauth, role()}
| {userauth_keyboard_interactive, role()}
@@ -589,13 +592,17 @@ handle_event(_, {#ssh_msg_kexinit{}=Kex, Payload}, {kexinit,Role,ReNeg},
handle_event(_, #ssh_msg_kexdh_init{} = Msg, {key_exchange,server,ReNeg}, D) ->
{ok, KexdhReply, Ssh1} = ssh_transport:handle_kexdh_init(Msg, D#data.ssh_params),
send_bytes(KexdhReply, D),
- {ok, NewKeys, Ssh} = ssh_transport:new_keys_message(Ssh1),
+ {ok, NewKeys, Ssh2} = ssh_transport:new_keys_message(Ssh1),
send_bytes(NewKeys, D),
+ {ok, ExtInfo, Ssh} = ssh_transport:ext_info_message(Ssh2),
+ send_bytes(ExtInfo, D),
{next_state, {new_keys,server,ReNeg}, D#data{ssh_params=Ssh}};
handle_event(_, #ssh_msg_kexdh_reply{} = Msg, {key_exchange,client,ReNeg}, D) ->
- {ok, NewKeys, Ssh} = ssh_transport:handle_kexdh_reply(Msg, D#data.ssh_params),
+ {ok, NewKeys, Ssh1} = ssh_transport:handle_kexdh_reply(Msg, D#data.ssh_params),
send_bytes(NewKeys, D),
+ {ok, ExtInfo, Ssh} = ssh_transport:ext_info_message(Ssh1),
+ send_bytes(ExtInfo, D),
{next_state, {new_keys,client,ReNeg}, D#data{ssh_params=Ssh}};
%%%---- diffie-hellman group exchange
@@ -620,13 +627,17 @@ handle_event(_, #ssh_msg_kex_dh_gex_group{} = Msg, {key_exchange,client,ReNeg},
handle_event(_, #ssh_msg_kex_ecdh_init{} = Msg, {key_exchange,server,ReNeg}, D) ->
{ok, KexEcdhReply, Ssh1} = ssh_transport:handle_kex_ecdh_init(Msg, D#data.ssh_params),
send_bytes(KexEcdhReply, D),
- {ok, NewKeys, Ssh} = ssh_transport:new_keys_message(Ssh1),
+ {ok, NewKeys, Ssh2} = ssh_transport:new_keys_message(Ssh1),
send_bytes(NewKeys, D),
+ {ok, ExtInfo, Ssh} = ssh_transport:ext_info_message(Ssh2),
+ send_bytes(ExtInfo, D),
{next_state, {new_keys,server,ReNeg}, D#data{ssh_params=Ssh}};
handle_event(_, #ssh_msg_kex_ecdh_reply{} = Msg, {key_exchange,client,ReNeg}, D) ->
- {ok, NewKeys, Ssh} = ssh_transport:handle_kex_ecdh_reply(Msg, D#data.ssh_params),
+ {ok, NewKeys, Ssh1} = ssh_transport:handle_kex_ecdh_reply(Msg, D#data.ssh_params),
send_bytes(NewKeys, D),
+ {ok, ExtInfo, Ssh} = ssh_transport:ext_info_message(Ssh1),
+ send_bytes(ExtInfo, D),
{next_state, {new_keys,client,ReNeg}, D#data{ssh_params=Ssh}};
@@ -635,8 +646,10 @@ handle_event(_, #ssh_msg_kex_ecdh_reply{} = Msg, {key_exchange,client,ReNeg}, D)
handle_event(_, #ssh_msg_kex_dh_gex_init{} = Msg, {key_exchange_dh_gex_init,server,ReNeg}, D) ->
{ok, KexGexReply, Ssh1} = ssh_transport:handle_kex_dh_gex_init(Msg, D#data.ssh_params),
send_bytes(KexGexReply, D),
- {ok, NewKeys, Ssh} = ssh_transport:new_keys_message(Ssh1),
+ {ok, NewKeys, Ssh2} = ssh_transport:new_keys_message(Ssh1),
send_bytes(NewKeys, D),
+ {ok, ExtInfo, Ssh} = ssh_transport:ext_info_message(Ssh2),
+ send_bytes(ExtInfo, D),
{next_state, {new_keys,server,ReNeg}, D#data{ssh_params=Ssh}};
@@ -645,30 +658,60 @@ handle_event(_, #ssh_msg_kex_dh_gex_init{} = Msg, {key_exchange_dh_gex_init,serv
handle_event(_, #ssh_msg_kex_dh_gex_reply{} = Msg, {key_exchange_dh_gex_reply,client,ReNeg}, D) ->
{ok, NewKeys, Ssh1} = ssh_transport:handle_kex_dh_gex_reply(Msg, D#data.ssh_params),
send_bytes(NewKeys, D),
- {next_state, {new_keys,client,ReNeg}, D#data{ssh_params=Ssh1}};
+ {ok, ExtInfo, Ssh} = ssh_transport:ext_info_message(Ssh1),
+ send_bytes(ExtInfo, D),
+ {next_state, {new_keys,client,ReNeg}, D#data{ssh_params=Ssh}};
%%% ######## {new_keys, client|server} ####
%% First key exchange round:
-handle_event(_, #ssh_msg_newkeys{} = Msg, {new_keys,Role,init}, D) ->
+handle_event(_, #ssh_msg_newkeys{} = Msg, {new_keys,client,init}, D) ->
{ok, Ssh1} = ssh_transport:handle_new_keys(Msg, D#data.ssh_params),
- Ssh = case Role of
- client ->
- {MsgReq, Ssh2} = ssh_auth:service_request_msg(Ssh1),
- send_bytes(MsgReq, D),
- Ssh2;
- server ->
- Ssh1
- end,
- {next_state, {service_request,Role}, D#data{ssh_params=Ssh}};
+ %% {ok, ExtInfo, Ssh2} = ssh_transport:ext_info_message(Ssh1),
+ %% send_bytes(ExtInfo, D),
+ {MsgReq, Ssh} = ssh_auth:service_request_msg(Ssh1),
+ send_bytes(MsgReq, D),
+ {next_state, {ext_info,client,init}, D#data{ssh_params=Ssh}};
+
+handle_event(_, #ssh_msg_newkeys{} = Msg, {new_keys,server,init}, D) ->
+ {ok, Ssh} = ssh_transport:handle_new_keys(Msg, D#data.ssh_params),
+ %% {ok, ExtInfo, Ssh} = ssh_transport:ext_info_message(Ssh1),
+ %% send_bytes(ExtInfo, D),
+ {next_state, {ext_info,server,init}, D#data{ssh_params=Ssh}};
%% Subsequent key exchange rounds (renegotiation):
handle_event(_, #ssh_msg_newkeys{} = Msg, {new_keys,Role,renegotiate}, D) ->
{ok, Ssh} = ssh_transport:handle_new_keys(Msg, D#data.ssh_params),
- {next_state, {connected,Role}, D#data{ssh_params=Ssh}};
+ %% {ok, ExtInfo, Ssh} = ssh_transport:ext_info_message(Ssh1),
+ %% send_bytes(ExtInfo, D),
+ {next_state, {ext_info,Role,renegotiate}, D#data{ssh_params=Ssh}};
+
+
+%%% ######## {ext_info, client|server, init|renegotiate} ####
+
+handle_event(_, #ssh_msg_ext_info{}=Msg, {ext_info,Role,init}, D0) ->
+ D = handle_ssh_msg_ext_info(Msg, D0),
+ {next_state, {service_request,Role}, D};
+
+handle_event(_, #ssh_msg_ext_info{}=Msg, {ext_info,Role,renegotiate}, D0) ->
+ D = handle_ssh_msg_ext_info(Msg, D0),
+ {next_state, {connected,Role}, D};
+
+handle_event(_, #ssh_msg_newkeys{}=Msg, {ext_info,_Role,renegotiate}, D) ->
+ {ok, Ssh} = ssh_transport:handle_new_keys(Msg, D#data.ssh_params),
+ {keep_state, D#data{ssh_params = Ssh}};
+
+
+handle_event(internal, Msg, {ext_info,Role,init}, D) when is_tuple(Msg) ->
+ %% If something else arrives, goto next state and handle the event in that one
+ {next_state, {service_request,Role}, D, [postpone]};
-%%% ######## {service_request, client|server}
+handle_event(internal, Msg, {ext_info,Role,renegotiate}, D) when is_tuple(Msg) ->
+ %% If something else arrives, goto next state and handle the event in that one
+ {next_state, {connected,Role}, D, [postpone]};
+
+%%% ######## {service_request, client|server} ####
handle_event(_, Msg = #ssh_msg_service_request{name=ServiceName}, StateName = {service_request,server}, D) ->
case ServiceName of
@@ -747,6 +790,11 @@ handle_event(_,
end;
%%---- userauth success to client
+handle_event(_, #ssh_msg_ext_info{}=Msg, {userauth,client}, D0) ->
+ %% FIXME: need new state to receive this msg!
+ D = handle_ssh_msg_ext_info(Msg, D0),
+ {keep_state, D};
+
handle_event(_, #ssh_msg_userauth_success{}, {userauth,client}, D=#data{ssh_params = Ssh}) ->
D#data.starter ! ssh_connected,
{next_state, {connected,client}, D#data{ssh_params=Ssh#ssh{authenticated = true}}};
@@ -849,6 +897,11 @@ handle_event(_, #ssh_msg_userauth_failure{}, {userauth_keyboard_interactive_info
end,
{next_state, {userauth,client}, D, [postpone]};
+handle_event(_, #ssh_msg_ext_info{}=Msg, {userauth_keyboard_interactive_info_response, client}, D0) ->
+ %% FIXME: need new state to receive this msg!
+ D = handle_ssh_msg_ext_info(Msg, D0),
+ {keep_state, D};
+
handle_event(_, #ssh_msg_userauth_success{}, {userauth_keyboard_interactive_info_response, client}, D) ->
{next_state, {userauth,client}, D, [postpone]};
@@ -1080,26 +1133,34 @@ handle_event({call,_}, _, StateName, _) when StateName /= {connected,server},
StateName /= {connected,client} ->
{keep_state_and_data, [postpone]};
-handle_event({call,From}, {request, ChannelPid, ChannelId, Type, Data, Timeout}, {connected,_}, D0) ->
+handle_event({call,From}, {request, ChannelPid, ChannelId, Type, Data, Timeout}, StateName, D0)
+ when element(1,StateName) == connected ;
+ element(1,StateName) == ext_info ->
D = handle_request(ChannelPid, ChannelId, Type, Data, true, From, D0),
%% Note reply to channel will happen later when reply is recived from peer on the socket
start_channel_request_timer(ChannelId, From, Timeout),
{keep_state, cache_request_idle_timer_check(D)};
-handle_event({call,From}, {request, ChannelId, Type, Data, Timeout}, {connected,_}, D0) ->
+handle_event({call,From}, {request, ChannelId, Type, Data, Timeout}, StateName, D0)
+ when element(1,StateName) == connected ;
+ element(1,StateName) == ext_info ->
D = handle_request(ChannelId, Type, Data, true, From, D0),
%% Note reply to channel will happen later when reply is recived from peer on the socket
start_channel_request_timer(ChannelId, From, Timeout),
{keep_state, cache_request_idle_timer_check(D)};
-handle_event({call,From}, {data, ChannelId, Type, Data, Timeout}, {connected,_}, D0) ->
+handle_event({call,From}, {data, ChannelId, Type, Data, Timeout}, StateName, D0)
+ when element(1,StateName) == connected ;
+ element(1,StateName) == ext_info ->
{{replies, Replies}, Connection} =
ssh_connection:channel_data(ChannelId, Type, Data, D0#data.connection_state, From),
{Repls,D} = send_replies(Replies, D0#data{connection_state = Connection}),
start_channel_request_timer(ChannelId, From, Timeout), % FIXME: No message exchange so why?
{keep_state, D, Repls};
-handle_event({call,From}, {eof, ChannelId}, {connected,_}, D0) ->
+handle_event({call,From}, {eof, ChannelId}, StateName, D0)
+ when element(1,StateName) == connected ;
+ element(1,StateName) == ext_info ->
case ssh_channel:cache_lookup(cache(D0), ChannelId) of
#channel{remote_id = Id, sent_close = false} ->
D = send_msg(ssh_connection:channel_eof_msg(Id), D0),
@@ -1110,8 +1171,9 @@ handle_event({call,From}, {eof, ChannelId}, {connected,_}, D0) ->
handle_event({call,From},
{open, ChannelPid, Type, InitialWindowSize, MaxPacketSize, Data, Timeout},
- {connected,_},
- D0) ->
+ StateName,
+ D0) when element(1,StateName) == connected ;
+ element(1,StateName) == ext_info ->
erlang:monitor(process, ChannelPid),
{ChannelId, D1} = new_channel_id(D0),
D2 = send_msg(ssh_connection:channel_open_msg(Type, ChannelId,
@@ -1131,7 +1193,9 @@ handle_event({call,From},
start_channel_request_timer(ChannelId, From, Timeout),
{keep_state, cache_cancel_idle_timer(D)};
-handle_event({call,From}, {send_window, ChannelId}, {connected,_}, D) ->
+handle_event({call,From}, {send_window, ChannelId}, StateName, D)
+ when element(1,StateName) == connected ;
+ element(1,StateName) == ext_info ->
Reply = case ssh_channel:cache_lookup(cache(D), ChannelId) of
#channel{send_window_size = WinSize,
send_packet_size = Packsize} ->
@@ -1141,7 +1205,9 @@ handle_event({call,From}, {send_window, ChannelId}, {connected,_}, D) ->
end,
{keep_state_and_data, [{reply,From,Reply}]};
-handle_event({call,From}, {recv_window, ChannelId}, {connected,_}, D) ->
+handle_event({call,From}, {recv_window, ChannelId}, StateName, D)
+ when element(1,StateName) == connected ;
+ element(1,StateName) == ext_info ->
Reply = case ssh_channel:cache_lookup(cache(D), ChannelId) of
#channel{recv_window_size = WinSize,
recv_packet_size = Packsize} ->
@@ -1151,7 +1217,9 @@ handle_event({call,From}, {recv_window, ChannelId}, {connected,_}, D) ->
end,
{keep_state_and_data, [{reply,From,Reply}]};
-handle_event({call,From}, {close, ChannelId}, {connected,_}, D0) ->
+handle_event({call,From}, {close, ChannelId}, StateName, D0)
+ when element(1,StateName) == connected ;
+ element(1,StateName) == ext_info ->
case ssh_channel:cache_lookup(cache(D0), ChannelId) of
#channel{remote_id = Id} = Channel ->
D1 = send_msg(ssh_connection:channel_close_msg(Id), D0),
@@ -1323,7 +1391,8 @@ handle_event(Type, Ev, StateName, D) ->
Descr =
case catch atom_to_list(element(1,Ev)) of
"ssh_msg_" ++_ when Type==internal ->
- "Message in wrong state";
+%% "Message in wrong state";
+lists:flatten(io_lib:format("Message ~p in wrong state (~p)", [element(1,Ev), StateName]));
_ ->
"Internal error"
end,
@@ -1516,6 +1585,8 @@ send_msg(Msg, State=#data{ssh_params=Ssh0}) when is_tuple(Msg) ->
send_bytes(Bytes, State),
State#data{ssh_params=Ssh}.
+send_bytes("", _D) ->
+ ok;
send_bytes(Bytes, #data{socket = Socket, transport_cb = Transport}) ->
_ = Transport:send(Socket, Bytes),
ok.
@@ -1622,6 +1693,19 @@ cache(#data{connection_state=C}) -> C#connection.channel_cache.
%%%----------------------------------------------------------------
+handle_ssh_msg_ext_info(#ssh_msg_ext_info{}, D=#data{ssh_params = #ssh{recv_ext_info=false}} ) ->
+ % The peer sent this although we didn't allow it!
+ D;
+handle_ssh_msg_ext_info(#ssh_msg_ext_info{data=Data}, D0) ->
+ lists:foldl(fun ext_info/2, D0, Data).
+
+%% ext_info({ExtName,ExtValue}, D0) ->
+%% D0;
+ext_info(_, D0) ->
+ %% Not implemented
+ D0.
+
+%%%----------------------------------------------------------------
handle_request(ChannelPid, ChannelId, Type, Data, WantReply, From, D) ->
case ssh_channel:cache_lookup(cache(D), ChannelId) of
#channel{remote_id = Id} = Channel ->
diff --git a/lib/ssh/src/ssh_dbg.erl b/lib/ssh/src/ssh_dbg.erl
index 0345bbdea7..9431bf1817 100644
--- a/lib/ssh/src/ssh_dbg.erl
+++ b/lib/ssh/src/ssh_dbg.erl
@@ -56,7 +56,7 @@ messages(Write, MangleArg) when is_function(Write,2),
dbg_ssh_messages() ->
dbg:tp(ssh_message,encode,1, x),
dbg:tp(ssh_message,decode,1, x),
- dbg:tpl(ssh_transport,select_algorithm,3, x),
+ dbg:tpl(ssh_transport,select_algorithm,4, x),
dbg:tp(ssh_transport,hello_version_msg,1, x),
dbg:tp(ssh_transport,handle_hello_version,1, x).
@@ -77,7 +77,7 @@ msg_formater({trace_ts,Pid,return_from,{ssh_message,decode,1},Msg,TS}, D) ->
msg_formater({trace_ts,_Pid,call,{ssh_transport,select_algorithm,_},_TS}, D) ->
D;
-msg_formater({trace_ts,Pid,return_from,{ssh_transport,select_algorithm,3},{ok,Alg},TS}, D) ->
+msg_formater({trace_ts,Pid,return_from,{ssh_transport,select_algorithm,_},{ok,Alg},TS}, D) ->
fmt("~n~s ~p ALGORITHMS~n~s~n", [ts(TS),Pid, wr_record(Alg)], D);
msg_formater({trace_ts,_Pid,call,{ssh_transport,hello_version_msg,_},_TS}, D) ->
@@ -160,6 +160,7 @@ shrink_bin(X) -> X.
?wr_record(ssh_msg_kexdh_init);
?wr_record(ssh_msg_kexdh_reply);
?wr_record(ssh_msg_newkeys);
+?wr_record(ssh_msg_ext_info);
?wr_record(ssh_msg_kex_dh_gex_request);
?wr_record(ssh_msg_kex_dh_gex_request_old);
?wr_record(ssh_msg_kex_dh_gex_group);
diff --git a/lib/ssh/src/ssh_message.erl b/lib/ssh/src/ssh_message.erl
index 562f040477..56f678876c 100644
--- a/lib/ssh/src/ssh_message.erl
+++ b/lib/ssh/src/ssh_message.erl
@@ -215,6 +215,16 @@ encode(#ssh_msg_service_accept{
}) ->
<<?Ebyte(?SSH_MSG_SERVICE_ACCEPT), ?Estring_utf8(Service)>>;
+encode(#ssh_msg_ext_info{
+ nr_extensions = N,
+ data = Data
+ }) ->
+ lists:foldl(fun({ExtName,ExtVal}, Acc) ->
+ <<Acc/binary, ?Estring(ExtName), ?Estring(ExtVal)>>
+ end,
+ <<?Ebyte(?SSH_MSG_EXT_INFO), ?Euint32(N)>>,
+ Data);
+
encode(#ssh_msg_newkeys{}) ->
<<?Ebyte(?SSH_MSG_NEWKEYS)>>;
@@ -435,6 +445,18 @@ decode(<<?BYTE(?SSH_MSG_USERAUTH_INFO_RESPONSE), ?UINT32(Num), Data/binary>>) ->
num_responses = Num,
data = Data};
+decode(<<?BYTE(?SSH_MSG_EXT_INFO), ?UINT32(N), BinData/binary>>) ->
+ Data = bin_foldr(
+ fun(Bin,Acc) when length(Acc) == N ->
+ {Bin,Acc};
+ (<<?DEC_BIN(V0,__0), ?DEC_BIN(V1,__1), Rest/binary>>, Acc) ->
+ {Rest,[{binary_to_list(V0),binary_to_list(V1)}|Acc]}
+ end, [], BinData),
+ #ssh_msg_ext_info{
+ nr_extensions = N,
+ data = Data
+ };
+
%%% Keyexchange messages
decode(<<?BYTE(?SSH_MSG_KEXINIT), Cookie:128, Data/binary>>) ->
decode_kex_init(Data, [Cookie, ssh_msg_kexinit], 10);
@@ -537,17 +559,28 @@ decode(<<?BYTE(?SSH_MSG_DEBUG), ?BYTE(Bool), ?DEC_BIN(Msg,__0), ?DEC_BIN(Lang,__
%%% Helper functions
%%%
+bin_foldr(Fun, Acc, Bin) ->
+ lists:reverse(bin_foldl(Fun, Acc, Bin)).
+
+bin_foldl(_, Acc, <<>>) -> Acc;
+bin_foldl(Fun, Acc0, Bin0) ->
+ {Bin,Acc} = Fun(Bin0,Acc0),
+ bin_foldl(Fun, Acc, Bin).
+
+%%%----------------------------------------------------------------
decode_keyboard_interactive_prompts(<<>>, Acc) ->
lists:reverse(Acc);
decode_keyboard_interactive_prompts(<<?DEC_BIN(Prompt,__0), ?BYTE(Bool), Bin/binary>>,
Acc) ->
decode_keyboard_interactive_prompts(Bin, [{Prompt, erl_boolean(Bool)} | Acc]).
+%%%----------------------------------------------------------------
erl_boolean(0) ->
false;
erl_boolean(1) ->
true.
+%%%----------------------------------------------------------------
decode_kex_init(<<?BYTE(Bool), ?UINT32(X)>>, Acc, 0) ->
list_to_tuple(lists:reverse([X, erl_boolean(Bool) | Acc]));
decode_kex_init(<<?BYTE(Bool)>>, Acc, 0) ->
diff --git a/lib/ssh/src/ssh_options.erl b/lib/ssh/src/ssh_options.erl
index ee3cdbb8a0..6e898b4fde 100644
--- a/lib/ssh/src/ssh_options.erl
+++ b/lib/ssh/src/ssh_options.erl
@@ -614,11 +614,23 @@ default(common) ->
},
{max_random_length_padding, def} =>
- #{default => ?MAX_RND_PADDING_LEN,
- chk => fun check_non_neg_integer/1,
- class => user_options
- }
- }.
+ #{default => ?MAX_RND_PADDING_LEN,
+ chk => fun check_non_neg_integer/1,
+ class => user_options
+ },
+
+ {send_ext_info, def} =>
+ #{default => true,
+ chk => fun erlang:is_boolean/1,
+ class => user_options
+ },
+
+ {recv_ext_info, def} =>
+ #{default => true,
+ chk => fun erlang:is_boolean/1,
+ class => user_options
+ }
+ }.
%%%================================================================
diff --git a/lib/ssh/src/ssh_transport.erl b/lib/ssh/src/ssh_transport.erl
index 6b47868d5c..d623d24529 100644
--- a/lib/ssh/src/ssh_transport.erl
+++ b/lib/ssh/src/ssh_transport.erl
@@ -38,6 +38,7 @@
handle_hello_version/1,
key_exchange_init_msg/1,
key_init/3, new_keys_message/1,
+ ext_info_message/1,
handle_kexinit_msg/3, handle_kexdh_init/2,
handle_kex_dh_gex_group/2, handle_kex_dh_gex_init/2, handle_kex_dh_gex_reply/2,
handle_new_keys/2, handle_kex_dh_gex_request/2,
@@ -230,7 +231,7 @@ key_exchange_init_msg(Ssh0) ->
kex_init(#ssh{role = Role, opts = Opts, available_host_keys = HostKeyAlgs}) ->
Random = ssh_bits:random(16),
PrefAlgs = ?GET_OPT(preferred_algorithms, Opts),
- kexinit_message(Role, Random, PrefAlgs, HostKeyAlgs).
+ kexinit_message(Role, Random, PrefAlgs, HostKeyAlgs, Opts).
key_init(client, Ssh, Value) ->
Ssh#ssh{c_keyinit = Value};
@@ -238,10 +239,11 @@ key_init(server, Ssh, Value) ->
Ssh#ssh{s_keyinit = Value}.
-kexinit_message(_Role, Random, Algs, HostKeyAlgs) ->
+kexinit_message(Role, Random, Algs, HostKeyAlgs, Opts) ->
#ssh_msg_kexinit{
cookie = Random,
- kex_algorithms = to_strings( get_algs(kex,Algs) ),
+ kex_algorithms = to_strings( get_algs(kex,Algs) )
+ ++ kex_ext_info(Role,Opts),
server_host_key_algorithms = HostKeyAlgs,
encryption_algorithms_client_to_server = c2s(cipher,Algs),
encryption_algorithms_server_to_client = s2c(cipher,Algs),
@@ -263,39 +265,42 @@ get_algs(Key, Algs) -> proplists:get_value(Key, Algs, default_algorithms(Key)).
to_strings(L) -> lists:map(fun erlang:atom_to_list/1, L).
new_keys_message(Ssh0) ->
- {SshPacket, Ssh} =
- ssh_packet(#ssh_msg_newkeys{}, Ssh0),
+ {SshPacket, Ssh1} = ssh_packet(#ssh_msg_newkeys{}, Ssh0),
+ Ssh = install_alg(snd, Ssh1),
{ok, SshPacket, Ssh}.
handle_kexinit_msg(#ssh_msg_kexinit{} = CounterPart, #ssh_msg_kexinit{} = Own,
- #ssh{role = client} = Ssh0) ->
- {ok, Algoritms} = select_algorithm(client, Own, CounterPart),
- case verify_algorithm(Algoritms) of
- true ->
- key_exchange_first_msg(Algoritms#alg.kex,
- Ssh0#ssh{algorithms = Algoritms});
- {false,Alg} ->
- %% TODO: Correct code?
- ssh_connection_handler:disconnect(
- #ssh_msg_disconnect{code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED,
- description = "Selection of key exchange algorithm failed: "
- ++ Alg
- })
+ #ssh{role = client} = Ssh) ->
+ try
+ {ok, Algorithms} = select_algorithm(client, Own, CounterPart, Ssh#ssh.opts),
+ true = verify_algorithm(Algorithms),
+ Algorithms
+ of
+ Algos ->
+ key_exchange_first_msg(Algos#alg.kex,
+ Ssh#ssh{algorithms = Algos})
+ catch
+ _:_ ->
+ ssh_connection_handler:disconnect(
+ #ssh_msg_disconnect{code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED,
+ description = "Selection of key exchange algorithm failed"})
end;
handle_kexinit_msg(#ssh_msg_kexinit{} = CounterPart, #ssh_msg_kexinit{} = Own,
- #ssh{role = server} = Ssh) ->
- {ok, Algoritms} = select_algorithm(server, CounterPart, Own),
- case verify_algorithm(Algoritms) of
- true ->
- {ok, Ssh#ssh{algorithms = Algoritms}};
- {false,Alg} ->
- ssh_connection_handler:disconnect(
- #ssh_msg_disconnect{code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED,
- description = "Selection of key exchange algorithm failed: "
- ++ Alg
- })
+ #ssh{role = server} = Ssh) ->
+ try
+ {ok, Algorithms} = select_algorithm(server, CounterPart, Own, Ssh#ssh.opts),
+ true = verify_algorithm(Algorithms),
+ Algorithms
+ of
+ Algos ->
+ {ok, Ssh#ssh{algorithms = Algos}}
+ catch
+ _:_ ->
+ ssh_connection_handler:disconnect(
+ #ssh_msg_disconnect{code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED,
+ description = "Selection of key exchange algorithm failed"})
end.
@@ -308,6 +313,8 @@ verify_algorithm(#alg{decrypt = undefined}) -> {false, "decrypt"};
verify_algorithm(#alg{compress = undefined}) -> {false, "compress"};
verify_algorithm(#alg{decompress = undefined}) -> {false, "decompress"};
verify_algorithm(#alg{kex = Kex}) ->
+ %% This also catches the error if 'ext-info-s' or 'ext-info-c' is selected.
+ %% (draft-ietf-curdle-ssh-ext-info-04 2.2)
case lists:member(Kex, supported_algorithms(kex)) of
true -> true;
false -> {false, "kex"}
@@ -414,9 +421,9 @@ handle_kexdh_reply(#ssh_msg_kexdh_reply{public_host_key = PeerPubHostKey,
case verify_host_key(Ssh0, PeerPubHostKey, H, H_SIG) of
ok ->
{SshPacket, Ssh} = ssh_packet(#ssh_msg_newkeys{}, Ssh0),
- {ok, SshPacket, Ssh#ssh{shared_secret = ssh_bits:mpint(K),
- exchanged_hash = H,
- session_id = sid(Ssh, H)}};
+ {ok, SshPacket, install_alg(snd, Ssh#ssh{shared_secret = ssh_bits:mpint(K),
+ exchanged_hash = H,
+ session_id = sid(Ssh, H)})};
Error ->
ssh_connection_handler:disconnect(
#ssh_msg_disconnect{
@@ -584,9 +591,9 @@ handle_kex_dh_gex_reply(#ssh_msg_kex_dh_gex_reply{public_host_key = PeerPubHostK
case verify_host_key(Ssh0, PeerPubHostKey, H, H_SIG) of
ok ->
{SshPacket, Ssh} = ssh_packet(#ssh_msg_newkeys{}, Ssh0),
- {ok, SshPacket, Ssh#ssh{shared_secret = ssh_bits:mpint(K),
- exchanged_hash = H,
- session_id = sid(Ssh, H)}};
+ {ok, SshPacket, install_alg(snd, Ssh#ssh{shared_secret = ssh_bits:mpint(K),
+ exchanged_hash = H,
+ session_id = sid(Ssh, H)})};
_Error ->
ssh_connection_handler:disconnect(
#ssh_msg_disconnect{
@@ -660,9 +667,9 @@ handle_kex_ecdh_reply(#ssh_msg_kex_ecdh_reply{public_host_key = PeerPubHostKey,
case verify_host_key(Ssh0, PeerPubHostKey, H, H_SIG) of
ok ->
{SshPacket, Ssh} = ssh_packet(#ssh_msg_newkeys{}, Ssh0),
- {ok, SshPacket, Ssh#ssh{shared_secret = ssh_bits:mpint(K),
- exchanged_hash = H,
- session_id = sid(Ssh, H)}};
+ {ok, SshPacket, install_alg(snd, Ssh#ssh{shared_secret = ssh_bits:mpint(K),
+ exchanged_hash = H,
+ session_id = sid(Ssh, H)})};
Error ->
ssh_connection_handler:disconnect(
#ssh_msg_disconnect{
@@ -682,7 +689,7 @@ handle_kex_ecdh_reply(#ssh_msg_kex_ecdh_reply{public_host_key = PeerPubHostKey,
%%%----------------------------------------------------------------
handle_new_keys(#ssh_msg_newkeys{}, Ssh0) ->
- try install_alg(Ssh0) of
+ try install_alg(rcv, Ssh0) of
#ssh{} = Ssh ->
{ok, Ssh}
catch
@@ -693,6 +700,34 @@ handle_new_keys(#ssh_msg_newkeys{}, Ssh0) ->
})
end.
+
+%%%----------------------------------------------------------------
+kex_ext_info(Role, Opts) ->
+ case ?GET_OPT(recv_ext_info,Opts) of
+ true when Role==client -> ["ext-info-c"];
+ true when Role==server -> ["ext-info-s"];
+ false -> []
+ end.
+
+ext_info_message(#ssh{role=client,
+ algorithms=#alg{send_ext_info=true}} = Ssh0) ->
+ %% FIXME: no extensions implemented for clients
+ {ok, "", Ssh0};
+
+ext_info_message(#ssh{role=server,
+ algorithms=#alg{send_ext_info=true}} = Ssh0) ->
+ AlgsList = lists:map(fun erlang:atom_to_list/1,
+ ssh_transport:default_algorithms(public_key)),
+ Msg = #ssh_msg_ext_info{nr_extensions = 1,
+ data = [{"server-sig-algs", string:join(AlgsList,",")}]
+ },
+ {SshPacket, Ssh} = ssh_packet(Msg, Ssh0),
+ {ok, SshPacket, Ssh};
+
+ext_info_message(Ssh0) ->
+ {ok, "", Ssh0}. % "" means: 'do not send'
+
+%%%----------------------------------------------------------------
%% select session id
sid(#ssh{session_id = undefined}, H) ->
H;
@@ -812,7 +847,7 @@ known_host_key(#ssh{opts = Opts, key_cb = {KeyCb,KeyCbOpts}, peer = {PeerName,_}
%%
%% The first algorithm in each list MUST be the preferred (guessed)
%% algorithm. Each string MUST contain at least one algorithm name.
-select_algorithm(Role, Client, Server) ->
+select_algorithm(Role, Client, Server, Opts) ->
{Encrypt0, Decrypt0} = select_encrypt_decrypt(Role, Client, Server),
{SendMac0, RecvMac0} = select_send_recv_mac(Role, Client, Server),
@@ -837,17 +872,34 @@ select_algorithm(Role, Client, Server) ->
Kex = select(Client#ssh_msg_kexinit.kex_algorithms,
Server#ssh_msg_kexinit.kex_algorithms),
- Alg = #alg{kex = Kex,
- hkey = HK,
- encrypt = Encrypt,
- decrypt = Decrypt,
- send_mac = SendMac,
- recv_mac = RecvMac,
- compress = Compression,
- decompress = Decompression,
- c_lng = C_Lng,
- s_lng = S_Lng},
- {ok, Alg}.
+ SendExtInfo =
+ %% To send we must have that option enabled and ...
+ ?GET_OPT(send_ext_info,Opts) andalso
+ %% ... the peer must have told us to send:
+ case Role of
+ server -> lists:member("ext-info-c", Client#ssh_msg_kexinit.kex_algorithms);
+ client -> lists:member("ext-info-s", Server#ssh_msg_kexinit.kex_algorithms)
+ end,
+
+ RecvExtInfo =
+ %% The peer should not send unless told so by us (which is
+ %% guided by an option).
+ %% (However a malicious peer could send anyway, so we must be prepared)
+ ?GET_OPT(recv_ext_info,Opts),
+
+ {ok, #alg{kex = Kex,
+ hkey = HK,
+ encrypt = Encrypt,
+ decrypt = Decrypt,
+ send_mac = SendMac,
+ recv_mac = RecvMac,
+ compress = Compression,
+ decompress = Decompression,
+ c_lng = C_Lng,
+ s_lng = S_Lng,
+ send_ext_info = SendExtInfo,
+ recv_ext_info = RecvExtInfo
+ }}.
%%% It is an agreed problem with RFC 5674 that if the selection is
@@ -928,45 +980,66 @@ select_compression_decompression(server, Client, Server) ->
Server#ssh_msg_kexinit.compression_algorithms_server_to_client),
{Compression, Decompression}.
-install_alg(SSH) ->
- SSH1 = alg_final(SSH),
- SSH2 = alg_setup(SSH1),
- alg_init(SSH2).
+%% DIr = rcv | snd
+install_alg(Dir, SSH) ->
+ SSH1 = alg_final(Dir, SSH),
+ SSH2 = alg_setup(Dir, SSH1),
+ alg_init(Dir, SSH2).
-alg_setup(SSH) ->
+alg_setup(snd, SSH) ->
ALG = SSH#ssh.algorithms,
SSH#ssh{kex = ALG#alg.kex,
hkey = ALG#alg.hkey,
encrypt = ALG#alg.encrypt,
- decrypt = ALG#alg.decrypt,
send_mac = ALG#alg.send_mac,
send_mac_size = mac_digest_size(ALG#alg.send_mac),
+ compress = ALG#alg.compress,
+ c_lng = ALG#alg.c_lng,
+ s_lng = ALG#alg.s_lng,
+ send_ext_info = ALG#alg.send_ext_info,
+ recv_ext_info = ALG#alg.recv_ext_info
+ };
+
+alg_setup(rcv, SSH) ->
+ ALG = SSH#ssh.algorithms,
+ SSH#ssh{kex = ALG#alg.kex,
+ hkey = ALG#alg.hkey,
+ decrypt = ALG#alg.decrypt,
recv_mac = ALG#alg.recv_mac,
recv_mac_size = mac_digest_size(ALG#alg.recv_mac),
- compress = ALG#alg.compress,
decompress = ALG#alg.decompress,
c_lng = ALG#alg.c_lng,
s_lng = ALG#alg.s_lng,
- algorithms = undefined
+ send_ext_info = ALG#alg.send_ext_info,
+ recv_ext_info = ALG#alg.recv_ext_info
}.
-alg_init(SSH0) ->
+
+alg_init(snd, SSH0) ->
{ok,SSH1} = send_mac_init(SSH0),
- {ok,SSH2} = recv_mac_init(SSH1),
- {ok,SSH3} = encrypt_init(SSH2),
- {ok,SSH4} = decrypt_init(SSH3),
- {ok,SSH5} = compress_init(SSH4),
- {ok,SSH6} = decompress_init(SSH5),
- SSH6.
-
-alg_final(SSH0) ->
+ {ok,SSH2} = encrypt_init(SSH1),
+ {ok,SSH3} = compress_init(SSH2),
+ SSH3;
+
+alg_init(rcv, SSH0) ->
+ {ok,SSH1} = recv_mac_init(SSH0),
+ {ok,SSH2} = decrypt_init(SSH1),
+ {ok,SSH3} = decompress_init(SSH2),
+ SSH3.
+
+
+alg_final(snd, SSH0) ->
{ok,SSH1} = send_mac_final(SSH0),
- {ok,SSH2} = recv_mac_final(SSH1),
- {ok,SSH3} = encrypt_final(SSH2),
- {ok,SSH4} = decrypt_final(SSH3),
- {ok,SSH5} = compress_final(SSH4),
- {ok,SSH6} = decompress_final(SSH5),
- SSH6.
+ {ok,SSH2} = encrypt_final(SSH1),
+ {ok,SSH3} = compress_final(SSH2),
+ SSH3;
+
+alg_final(rcv, SSH0) ->
+ {ok,SSH1} = recv_mac_final(SSH0),
+ {ok,SSH2} = decrypt_final(SSH1),
+ {ok,SSH3} = decompress_final(SSH2),
+ SSH3.
+
select_all(CL, SL) when length(CL) + length(SL) < ?MAX_NUM_ALGORITHMS ->
A = CL -- SL, %% algortihms only used by client
diff --git a/lib/ssh/src/ssh_transport.hrl b/lib/ssh/src/ssh_transport.hrl
index 19b3f5c437..faae6008f2 100644
--- a/lib/ssh/src/ssh_transport.hrl
+++ b/lib/ssh/src/ssh_transport.hrl
@@ -48,6 +48,7 @@
-define(SSH_MSG_DEBUG, 4).
-define(SSH_MSG_SERVICE_REQUEST, 5).
-define(SSH_MSG_SERVICE_ACCEPT, 6).
+-define(SSH_MSG_EXT_INFO, 7).
-define(SSH_MSG_KEXINIT, 20).
-define(SSH_MSG_NEWKEYS, 21).
@@ -88,6 +89,20 @@
name %% string
}).
+-record(ssh_msg_ext_info,
+ {
+ nr_extensions, %% uint32
+
+ %% repeat the following 2 fields "nr-extensions" times:
+ %% string extension-name
+ %% string extension-value
+
+ data %% [{extension-name, %% string
+ %% extension-value}, %% string
+ %% ...
+ %% ]
+ }).
+
-record(ssh_msg_kexinit,
{
cookie, %% random(16)