From 92a9ddf4c4169c486c1b3bfe958464a90b553289 Mon Sep 17 00:00:00 2001 From: Ingela Anderton Andin Date: Fri, 29 May 2015 10:15:51 +0200 Subject: ssh: handle that inet:getopts(Socket, [recbuf]) may return {ok, []} If something bad happens and the socket is closed the call inet:getopts(Socket, [recbuf]) may return {ok, []}. We want to treat this as a fatal error and terminate gracefully. The same goes for the case that inet:getopts returns {error, Reason} that was not handled either. --- lib/ssh/src/ssh_connection_handler.erl | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) (limited to 'lib/ssh') diff --git a/lib/ssh/src/ssh_connection_handler.erl b/lib/ssh/src/ssh_connection_handler.erl index 0f6162db60..d4bbb0b32e 100644 --- a/lib/ssh/src/ssh_connection_handler.erl +++ b/lib/ssh/src/ssh_connection_handler.erl @@ -326,9 +326,13 @@ info(ConnectionHandler, ChannelProcess) -> hello(socket_control, #state{socket = Socket, ssh_params = Ssh} = State) -> VsnMsg = ssh_transport:hello_version_msg(string_version(Ssh)), send_msg(VsnMsg, State), - {ok, [{recbuf, Size}]} = inet:getopts(Socket, [recbuf]), - inet:setopts(Socket, [{packet, line}, {active, once}, {recbuf, ?MAX_PROTO_VERSION}]), - {next_state, hello, State#state{recbuf = Size}}; + case getopt(recbuf, Socket) of + {ok, Size} -> + inet:setopts(Socket, [{packet, line}, {active, once}, {recbuf, ?MAX_PROTO_VERSION}]), + {next_state, hello, State#state{recbuf = Size}}; + {error, Reason} -> + {stop, {shutdown, Reason}, State} + end; hello({info_line, _Line},#state{role = client, socket = Socket} = State) -> %% The server may send info lines before the version_exchange @@ -1719,3 +1723,12 @@ start_timeout(_,_, infinity) -> ok; start_timeout(Channel, From, Time) -> erlang:send_after(Time, self(), {timeout, {Channel, From}}). + +getopt(Opt, Socket) -> + case inet:getopts(Socket, [Opt]) of + {ok, [{Opt, Value}]} -> + {ok, Value}; + Other -> + {error, {unexpected_getopts_return, Other}} + end. + -- cgit v1.2.3 From 979b94a3f31697fe06f329660f2ea9e48944490a Mon Sep 17 00:00:00 2001 From: Hans Date: Tue, 26 May 2015 19:23:04 +0200 Subject: ssh: Set max num algoritms in msg_kexinit negotiation This is to prevent some dos-attac scenarios. The limit is hard-coded. --- lib/ssh/src/ssh_transport.erl | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'lib/ssh') diff --git a/lib/ssh/src/ssh_transport.erl b/lib/ssh/src/ssh_transport.erl index 8669be570e..34b76f1b08 100644 --- a/lib/ssh/src/ssh_transport.erl +++ b/lib/ssh/src/ssh_transport.erl @@ -519,10 +519,15 @@ alg_final(SSH0) -> {ok,SSH6} = decompress_final(SSH5), SSH6. -select_all(CL, SL) -> +select_all(CL, SL) when length(CL) + length(SL) < 50 -> A = CL -- SL, %% algortihms only used by client %% algorithms used by client and server (client pref) - lists:map(fun(ALG) -> list_to_atom(ALG) end, (CL -- A)). + lists:map(fun(ALG) -> list_to_atom(ALG) end, (CL -- A)); +select_all(_CL, _SL) -> + throw(#ssh_msg_disconnect{code = ?SSH_DISCONNECT_PROTOCOL_ERROR, + description = "Too many algorithms", + language = "en"}). + select([], []) -> none; -- cgit v1.2.3 From 59b5884dfef313c09d79f3c18063297c81fb67d5 Mon Sep 17 00:00:00 2001 From: Hans Nilsson Date: Fri, 8 May 2015 15:39:38 +0200 Subject: ssh: Check e and f parameters in kexdh rfc 4253 says in section 8 that: "Values of 'e' or 'f' that are not in the range [1, p-1] MUST NOT be sent or accepted by either side. If this condition is violated, the key exchange fails." This commit implements the reception check. --- lib/ssh/src/ssh_transport.erl | 50 +++++++++++++++++++++++++++++-------------- 1 file changed, 34 insertions(+), 16 deletions(-) (limited to 'lib/ssh') diff --git a/lib/ssh/src/ssh_transport.erl b/lib/ssh/src/ssh_transport.erl index 34b76f1b08..6c0873fd9e 100644 --- a/lib/ssh/src/ssh_transport.erl +++ b/lib/ssh/src/ssh_transport.erl @@ -240,20 +240,30 @@ key_exchange_first_msg('diffie-hellman-group-exchange-sha1', Ssh0) -> handle_kexdh_init(#ssh_msg_kexdh_init{e = E}, Ssh0) -> {G, P} = dh_group1(), - {Private, Public} = dh_gen_key(G, P, 1024), - K = ssh_math:ipow(E, Private, P), - Key = get_host_key(Ssh0), - H = kex_h(Ssh0, Key, E, Public, K), - H_SIG = sign_host_key(Ssh0, Key, H), - {SshPacket, Ssh1} = ssh_packet(#ssh_msg_kexdh_reply{public_host_key = Key, - f = Public, - h_sig = H_SIG - }, Ssh0), - - {ok, SshPacket, Ssh1#ssh{keyex_key = {{Private, Public}, {G, P}}, - shared_secret = K, - exchanged_hash = H, - session_id = sid(Ssh1, H)}}. + if + 1= + {Private, Public} = dh_gen_key(G, P, 1024), + K = ssh_math:ipow(E, Private, P), + Key = get_host_key(Ssh0), + H = kex_h(Ssh0, Key, E, Public, K), + H_SIG = sign_host_key(Ssh0, Key, H), + {SshPacket, Ssh1} = ssh_packet(#ssh_msg_kexdh_reply{public_host_key = Key, + f = Public, + h_sig = H_SIG + }, Ssh0), + + {ok, SshPacket, Ssh1#ssh{keyex_key = {{Private, Public}, {G, P}}, + shared_secret = K, + exchanged_hash = H, + session_id = sid(Ssh1, H)}}; + true -> + Error = {error,bad_e_from_peer}, + Disconnect = #ssh_msg_disconnect{ + code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, + description = "Key exchange failed, 'f' out of bounds", + language = "en"}, + throw({Error, Disconnect}) + end. handle_kex_dh_gex_group(#ssh_msg_kex_dh_gex_group{p = P, g = G}, Ssh0) -> {Private, Public} = dh_gen_key(G,P,1024), @@ -277,7 +287,7 @@ handle_new_keys(#ssh_msg_newkeys{}, Ssh0) -> %% %% Select algorithms handle_kexdh_reply(#ssh_msg_kexdh_reply{public_host_key = HostKey, f = F, h_sig = H_SIG}, - #ssh{keyex_key = {{Private, Public}, {_G, P}}} = Ssh0) -> + #ssh{keyex_key = {{Private, Public}, {_G, P}}} = Ssh0) when 1= K = ssh_math:ipow(F, Private, P), H = kex_h(Ssh0, HostKey, Public, F, K), @@ -293,7 +303,15 @@ handle_kexdh_reply(#ssh_msg_kexdh_reply{public_host_key = HostKey, f = F, description = "Key exchange failed", language = "en"}, throw({Error, Disconnect}) - end. + end; +handle_kexdh_reply(#ssh_msg_kexdh_reply{}, _SSH) -> + Error = {error,bad_f_from_peer}, + Disconnect = #ssh_msg_disconnect{ + code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED, + description = "Key exchange failed, 'f' out of bounds", + language = "en"}, + throw({Error, Disconnect}). + handle_kex_dh_gex_request(#ssh_msg_kex_dh_gex_request{min = _Min, n = _NBits, -- cgit v1.2.3 From 2d9a5afcd801837be7637048977982bd9e1330f5 Mon Sep 17 00:00:00 2001 From: Hans Date: Wed, 27 May 2015 16:46:24 +0200 Subject: ssh: Implement keyboard_interactive on server side --- lib/ssh/src/ssh.erl | 9 ++++ lib/ssh/src/ssh_auth.erl | 80 ++++++++++++++++++++++++++++++++++ lib/ssh/src/ssh_connection_handler.erl | 19 ++++++-- 3 files changed, 104 insertions(+), 4 deletions(-) (limited to 'lib/ssh') diff --git a/lib/ssh/src/ssh.erl b/lib/ssh/src/ssh.erl index 71e7d77475..7ed17618e7 100644 --- a/lib/ssh/src/ssh.erl +++ b/lib/ssh/src/ssh.erl @@ -331,6 +331,8 @@ handle_option([{exec, _} = Opt | Rest], SocketOptions, SshOptions) -> handle_option(Rest, SocketOptions, [handle_ssh_option(Opt) | SshOptions]); handle_option([{auth_methods, _} = Opt | Rest], SocketOptions, SshOptions) -> handle_option(Rest, SocketOptions, [handle_ssh_option(Opt) | SshOptions]); +handle_option([{auth_method_kb_interactive_data, _} = Opt | Rest], SocketOptions, SshOptions) -> + handle_option(Rest, SocketOptions, [handle_ssh_option(Opt) | SshOptions]); handle_option([{pref_public_key_algs, _} = Opt | Rest], SocketOptions, SshOptions) -> handle_option(Rest, SocketOptions, [handle_ssh_option(Opt) | SshOptions]); handle_option([{quiet_mode, _} = Opt|Rest], SocketOptions, SshOptions) -> @@ -411,6 +413,13 @@ handle_ssh_option({exec, Function} = Opt) when is_function(Function) -> Opt; handle_ssh_option({auth_methods, Value} = Opt) when is_list(Value) -> Opt; +handle_ssh_option({auth_method_kb_interactive_data, {Name,Instruction,Prompt,Echo}} = Opt) when is_list(Name), + is_list(Instruction), + is_list(Prompt), + is_boolean(Echo) -> + Opt; +handle_ssh_option({auth_method_kb_interactive_data, F} = Opt) when is_function(F,3) -> + Opt; handle_ssh_option({infofun, Value} = Opt) when is_function(Value) -> Opt; handle_ssh_option({connectfun, Value} = Opt) when is_function(Value) -> diff --git a/lib/ssh/src/ssh_auth.erl b/lib/ssh/src/ssh_auth.erl index 45c4d52d7e..9d1ab14ce9 100644 --- a/lib/ssh/src/ssh_auth.erl +++ b/lib/ssh/src/ssh_auth.erl @@ -257,6 +257,54 @@ handle_userauth_request(#ssh_msg_userauth_request{user = User, key_blob = KeyBlob}, Ssh)} end; +handle_userauth_request(#ssh_msg_userauth_request{user = User, + service = "ssh-connection", + method = "keyboard-interactive", + data = _}, + _, #ssh{opts = Opts} = Ssh) -> + %% RFC4256 + %% The data field contains: + %% - language tag (deprecated). If =/=[] SHOULD use it however. We skip + %% it for simplicity. + %% - submethods. "... the user can give a hint of which actual methods + %% he wants to use. ...". It's a "MAY use" so we skip + %% it. It also needs an understanding between the client + %% and the server. + %% + %% "The server MUST reply with an SSH_MSG_USERAUTH_SUCCESS, + %% SSH_MSG_USERAUTH_FAILURE, or SSH_MSG_USERAUTH_INFO_REQUEST message." + Default = {"SSH server", + "Enter password for \""++User++"\"", + "pwd: ", + false}, + + {Name, Instruction, Prompt, Echo} = + case proplists:get_value(auth_method_kb_interactive_data, Opts) of + undefined -> + Default; + {_,_,_,_}=V -> + V; + F when is_function(F) -> + {_,PeerName} = Ssh#ssh.peer, + F(PeerName, User, "ssh-connection") + end, + EchoEnc = case Echo of + true -> <>; + false -> <> + end, + Msg = #ssh_msg_userauth_info_request{name = unicode:characters_to_list(Name), + instruction = unicode:characters_to_list(Instruction), + language_tag = "", + num_prompts = 1, + data = <> + }, + {not_authorized, {User, undefined}, + ssh_transport:ssh_packet(Msg, Ssh#ssh{user = User, + opts = [{max_kb_tries,3},{kb_userauth_info_msg,Msg}|Opts] + })}; + handle_userauth_request(#ssh_msg_userauth_request{user = User, service = "ssh-connection", method = Other}, _, @@ -280,6 +328,38 @@ handle_userauth_info_request( #ssh_msg_userauth_info_response{num_responses = NumPrompts, data = Responses}, Ssh)}. +handle_userauth_info_response(#ssh_msg_userauth_info_response{num_responses = 1, + data = <>}, + #ssh{opts = Opts0, + user = User} = Ssh) -> + NumTriesLeft = proplists:get_value(max_kb_tries, Opts0, 0) - 1, + Opts = lists:keydelete(max_kb_tries,1,Opts0), + case check_password(User, unicode:characters_to_list(Password), Opts) of + true -> + {authorized, User, + ssh_transport:ssh_packet(#ssh_msg_userauth_success{}, Ssh)}; + false when NumTriesLeft > 0 -> + UserAuthInfoMsg = + (proplists:get_value(kb_userauth_info_msg,Opts)) + #ssh_msg_userauth_info_request{name = "", + instruction = + lists:concat( + ["Bad user or password, try again. ", + integer_to_list(NumTriesLeft), + " tries left."])}, + {not_authorized, {User, undefined}, + ssh_transport:ssh_packet(UserAuthInfoMsg, + Ssh#ssh{opts = [{max_kb_tries,NumTriesLeft}|Opts]})}; + + false -> + {not_authorized, {User, {error,"Bad user or password"}}, + ssh_transport:ssh_packet(#ssh_msg_userauth_failure{ + authentications = "", + partial_success = false}, + Ssh#ssh{opts = lists:keydelete(kb_userauth_info_msg,1,Opts)} + )} + end; + handle_userauth_info_response(#ssh_msg_userauth_info_response{}, _Auth) -> throw(#ssh_msg_disconnect{code = ?SSH_DISCONNECT_SERVICE_NOT_AVAILABLE, diff --git a/lib/ssh/src/ssh_connection_handler.erl b/lib/ssh/src/ssh_connection_handler.erl index 0f6162db60..3161c1f291 100644 --- a/lib/ssh/src/ssh_connection_handler.erl +++ b/lib/ssh/src/ssh_connection_handler.erl @@ -496,10 +496,21 @@ userauth(#ssh_msg_userauth_info_request{} = Msg, {next_state, userauth, next_packet(State#state{ssh_params = Ssh})}; userauth(#ssh_msg_userauth_info_response{} = Msg, - #state{ssh_params = #ssh{role = server} = Ssh0} = State) -> - {ok, {Reply, Ssh}} = ssh_auth:handle_userauth_info_response(Msg, Ssh0), - send_msg(Reply, State), - {next_state, userauth, next_packet(State#state{ssh_params = Ssh})}; + #state{ssh_params = #ssh{role = server, + peer = {_, Address}} = Ssh0, + opts = Opts, starter = Pid} = State) -> + case ssh_auth:handle_userauth_info_response(Msg, Ssh0) of + {authorized, User, {Reply, Ssh}} -> + send_msg(Reply, State), + Pid ! ssh_connected, + connected_fun(User, Address, "keyboard-interactive", Opts), + {next_state, connected, + next_packet(State#state{auth_user = User, ssh_params = Ssh})}; + {not_authorized, {User, Reason}, {Reply, Ssh}} -> + retry_fun(User, Address, Reason, Opts), + send_msg(Reply, State), + {next_state, userauth, next_packet(State#state{ssh_params = Ssh})} + end; userauth(#ssh_msg_userauth_success{}, #state{ssh_params = #ssh{role = client} = Ssh, starter = Pid} = State) -> -- cgit v1.2.3 From 4cb16a7ed0f0491ccf8defbeb62a9b0e96923372 Mon Sep 17 00:00:00 2001 From: Hans Date: Thu, 28 May 2015 20:58:28 +0200 Subject: ssh: Plain text message returned for invalid version exchange This is how OpenSSH does. The bytes returned will be put on the user's tty, so it is better with text than a ssh_msg_disconnect --- lib/ssh/src/ssh_connection_handler.erl | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) (limited to 'lib/ssh') diff --git a/lib/ssh/src/ssh_connection_handler.erl b/lib/ssh/src/ssh_connection_handler.erl index 3161c1f291..bc652b81b8 100644 --- a/lib/ssh/src/ssh_connection_handler.erl +++ b/lib/ssh/src/ssh_connection_handler.erl @@ -335,13 +335,12 @@ hello({info_line, _Line},#state{role = client, socket = Socket} = State) -> inet:setopts(Socket, [{active, once}]), {next_state, hello, State}; -hello({info_line, _Line},#state{role = server} = State) -> - DisconnectMsg = - #ssh_msg_disconnect{code = - ?SSH_DISCONNECT_PROTOCOL_ERROR, - description = "Did not receive expected protocol version exchange", - language = "en"}, - handle_disconnect(DisconnectMsg, State); +hello({info_line, _Line},#state{role = server, + socket = Socket, + transport_cb = Transport } = State) -> + %% as openssh + Transport:send(Socket, "Protocol mismatch."), + {stop, {shutdown,"Protocol mismatch in version exchange."}, State}; hello({version_exchange, Version}, #state{ssh_params = Ssh0, socket = Socket, -- cgit v1.2.3 From 3f600aa0048b6515616774f0a289a88cb66affbe Mon Sep 17 00:00:00 2001 From: Hans Date: Fri, 29 May 2015 11:40:34 +0200 Subject: ssh: update ssh version --- lib/ssh/vsn.mk | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib/ssh') diff --git a/lib/ssh/vsn.mk b/lib/ssh/vsn.mk index 40bda0c19f..9d486f8890 100644 --- a/lib/ssh/vsn.mk +++ b/lib/ssh/vsn.mk @@ -1,4 +1,4 @@ #-*-makefile-*- ; force emacs to enter makefile-mode -SSH_VSN = 3.2.3 +SSH_VSN = 3.2.4 APP_VSN = "ssh-$(SSH_VSN)" -- cgit v1.2.3 From 69f114203690b84d7261b68b1893cb578536eca9 Mon Sep 17 00:00:00 2001 From: Erlang/OTP Date: Mon, 1 Jun 2015 12:06:48 +0200 Subject: Update release notes --- lib/ssh/doc/src/notes.xml | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) (limited to 'lib/ssh') diff --git a/lib/ssh/doc/src/notes.xml b/lib/ssh/doc/src/notes.xml index 579a3ae4a8..c77ee1e77a 100644 --- a/lib/ssh/doc/src/notes.xml +++ b/lib/ssh/doc/src/notes.xml @@ -29,6 +29,33 @@ notes.xml +
Ssh 3.2.4 + +
Fixed Bugs and Malfunctions + + +

+ Gracefully terminate if sockets is unexpectedly closed.

+

+ Own Id: OTP-12782

+ + +

+ Made Codenomicon Defensics test suite pass: + limit number of algorithms in kexinit + message check 'e' and 'f' parameters in + kexdh implement 'keyboard-interactive' user + authentication on server side return plain + text message to bad version exchange message +

+

+ Own Id: OTP-12784

+ + +
+ +
+
Ssh 3.2.3
Fixed Bugs and Malfunctions -- cgit v1.2.3