diff options
Diffstat (limited to 'lib/ssh/src/ssh_auth.erl')
-rw-r--r-- | lib/ssh/src/ssh_auth.erl | 246 |
1 files changed, 160 insertions, 86 deletions
diff --git a/lib/ssh/src/ssh_auth.erl b/lib/ssh/src/ssh_auth.erl index 45fd907383..df9a97c8f8 100644 --- a/lib/ssh/src/ssh_auth.erl +++ b/lib/ssh/src/ssh_auth.erl @@ -1,7 +1,7 @@ %% %% %CopyrightBegin% %% -%% Copyright Ericsson AB 2008-2013. All Rights Reserved. +%% Copyright Ericsson AB 2008-2014. All Rights Reserved. %% %% The contents of this file are subject to the Erlang Public License, %% Version 1.1, (the "License"); you may not use this file except in @@ -30,7 +30,8 @@ -export([publickey_msg/1, password_msg/1, keyboard_interactive_msg/1, service_request_msg/1, init_userauth_request_msg/1, userauth_request_msg/1, handle_userauth_request/3, - handle_userauth_info_request/3, handle_userauth_info_response/2 + handle_userauth_info_request/3, handle_userauth_info_response/2, + default_public_key_algorithms/0 ]). %%-------------------------------------------------------------------- @@ -115,36 +116,16 @@ init_userauth_request_msg(#ssh{opts = Opts} = Ssh) -> service = "ssh-connection", method = "none", data = <<>>}, - case proplists:get_value(pref_public_key_algs, Opts, false) of - false -> - FirstAlg = proplists:get_value(public_key_alg, Opts, ?PREFERRED_PK_ALG), - SecondAlg = other_alg(FirstAlg), - AllowUserInt = proplists:get_value(user_interaction, Opts, true), - Prefs = method_preference(FirstAlg, SecondAlg, AllowUserInt), - ssh_transport:ssh_packet(Msg, Ssh#ssh{user = User, - userauth_preference = Prefs, - userauth_methods = none, - service = "ssh-connection"}); - Algs -> - FirstAlg = lists:nth(1, Algs), - case length(Algs) =:= 2 of - true -> - SecondAlg = other_alg(FirstAlg), - AllowUserInt = proplists:get_value(user_interaction, Opts, true), - Prefs = method_preference(FirstAlg, SecondAlg, AllowUserInt), - ssh_transport:ssh_packet(Msg, Ssh#ssh{user = User, - userauth_preference = Prefs, - userauth_methods = none, - service = "ssh-connection"}); - _ -> - AllowUserInt = proplists:get_value(user_interaction, Opts, true), - Prefs = method_preference(FirstAlg, AllowUserInt), - ssh_transport:ssh_packet(Msg, Ssh#ssh{user = User, - userauth_preference = Prefs, - userauth_methods = none, - service = "ssh-connection"}) - end - end; + + + Algs = proplists:get_value(public_key, + proplists:get_value(preferred_algorithms, Opts, []), + default_public_key_algorithms()), + Prefs = method_preference(Algs), + ssh_transport:ssh_packet(Msg, Ssh#ssh{user = User, + userauth_preference = Prefs, + userauth_methods = none, + service = "ssh-connection"}); {error, no_user} -> ErrStr = "Could not determine the users name", throw(#ssh_msg_disconnect{code = ?SSH_DISCONNECT_ILLEGAL_USER_NAME, @@ -187,9 +168,8 @@ handle_userauth_request(#ssh_msg_service_request{name = handle_userauth_request(#ssh_msg_userauth_request{user = User, service = "ssh-connection", method = "password", - data = Data}, _, + data = <<?FALSE, ?UINT32(Sz), BinPwd:Sz/binary>>}, _, #ssh{opts = Opts} = Ssh) -> - <<_:8, ?UINT32(Sz), BinPwd:Sz/binary>> = Data, Password = unicode:characters_to_list(BinPwd), case check_password(User, Password, Opts) of true -> @@ -204,6 +184,27 @@ handle_userauth_request(#ssh_msg_userauth_request{user = User, handle_userauth_request(#ssh_msg_userauth_request{user = User, service = "ssh-connection", + method = "password", + data = <<?TRUE, + _/binary + %% ?UINT32(Sz1), OldBinPwd:Sz1/binary, + %% ?UINT32(Sz2), NewBinPwd:Sz2/binary + >> + }, _, + Ssh) -> + %% Password change without us having sent SSH_MSG_USERAUTH_PASSWD_CHANGEREQ (because we never do) + %% RFC 4252 says: + %% SSH_MSG_USERAUTH_FAILURE without partial success - The password + %% has not been changed. Either password changing was not supported, + %% or the old password was bad. + + {not_authorized, {User, {error,"Password change not supported"}}, + ssh_transport:ssh_packet(#ssh_msg_userauth_failure{ + authentications = "", + partial_success = false}, Ssh)}; + +handle_userauth_request(#ssh_msg_userauth_request{user = User, + service = "ssh-connection", method = "none"}, _, #ssh{userauth_supported_methods = Methods} = Ssh) -> {not_authorized, {User, undefined}, @@ -242,6 +243,54 @@ handle_userauth_request(#ssh_msg_userauth_request{user = User, 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 -> <<?TRUE>>; + false -> <<?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 = <<?STRING(unicode:characters_to_binary(Prompt)), + EchoEnc/binary + >> + }, + {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}, _, #ssh{userauth_supported_methods = Methods} = Ssh) -> {not_authorized, {User, {authmethod, Other}}, @@ -256,15 +305,44 @@ handle_userauth_info_request( data = Data}, IoCb, #ssh{opts = Opts} = Ssh) -> PromptInfos = decode_keyboard_interactive_prompts(NumPrompts,Data), - Resps = keyboard_interact_get_responses(IoCb, Opts, + Responses = keyboard_interact_get_responses(IoCb, Opts, Name, Instr, PromptInfos), - RespBin = list_to_binary( - lists:map(fun(S) -> <<?STRING(list_to_binary(S))>> end, - Resps)), {ok, ssh_transport:ssh_packet( #ssh_msg_userauth_info_response{num_responses = NumPrompts, - data = RespBin}, Ssh)}. + data = Responses}, Ssh)}. + +handle_userauth_info_response(#ssh_msg_userauth_info_response{num_responses = 1, + data = <<?UINT32(Sz), Password:Sz/binary>>}, + #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) -> @@ -273,29 +351,20 @@ handle_userauth_info_response(#ssh_msg_userauth_info_response{}, "keyboard-interactive", language = "en"}). + +default_public_key_algorithms() -> ?PREFERRED_PK_ALGS. + %%-------------------------------------------------------------------- %%% Internal functions %%-------------------------------------------------------------------- -method_preference(Alg1, Alg2, true) -> - [{"publickey", ?MODULE, publickey_msg, [Alg1]}, - {"publickey", ?MODULE, publickey_msg,[Alg2]}, - {"password", ?MODULE, password_msg, []}, - {"keyboard-interactive", ?MODULE, keyboard_interactive_msg, []} - ]; -method_preference(Alg1, Alg2, false) -> - [{"publickey", ?MODULE, publickey_msg, [Alg1]}, - {"publickey", ?MODULE, publickey_msg,[Alg2]}, - {"password", ?MODULE, password_msg, []} - ]. -method_preference(Alg1, true) -> - [{"publickey", ?MODULE, publickey_msg, [Alg1]}, - {"password", ?MODULE, password_msg, []}, - {"keyboard-interactive", ?MODULE, keyboard_interactive_msg, []} - ]; -method_preference(Alg1, false) -> - [{"publickey", ?MODULE, publickey_msg, [Alg1]}, - {"password", ?MODULE, password_msg, []} - ]. +method_preference(Algs) -> + lists:foldr(fun(A, Acc) -> + [{"publickey", ?MODULE, publickey_msg, [A]} | Acc] + end, + [{"password", ?MODULE, password_msg, []}, + {"keyboard-interactive", ?MODULE, keyboard_interactive_msg, []} + ], + Algs). user_name(Opts) -> Env = case os:type() of @@ -362,35 +431,29 @@ build_sig_data(SessionId, User, Service, KeyBlob, Alg) -> algorithm_string('ssh-rsa') -> "ssh-rsa"; algorithm_string('ssh-dss') -> - "ssh-dss". + "ssh-dss". decode_keyboard_interactive_prompts(_NumPrompts, Data) -> ssh_message:decode_keyboard_interactive_prompts(Data, []). keyboard_interact_get_responses(IoCb, Opts, Name, Instr, PromptInfos) -> NumPrompts = length(PromptInfos), - case proplists:get_value(keyboard_interact_fun, Opts) of - undefined when NumPrompts == 1 -> - %% Special case/fallback for just one prompt - %% (assumed to be the password prompt) - case proplists:get_value(password, Opts) of - undefined -> keyboard_interact(IoCb, Name, Instr, PromptInfos, Opts); - PW -> [PW] - end; - undefined -> - keyboard_interact(IoCb, Name, Instr, PromptInfos, Opts); - KbdInteractFun -> - Prompts = lists:map(fun({Prompt, _Echo}) -> Prompt end, - PromptInfos), - case KbdInteractFun(Name, Instr, Prompts) of - Rs when length(Rs) == NumPrompts -> - Rs; - Rs -> - erlang:error({mismatching_number_of_responses, - {got,Rs}, - {expected,NumPrompts}}) - end - end. + keyboard_interact_get_responses(proplists:get_value(user_interaction, Opts, true), + proplists:get_value(keyboard_interact_fun, Opts), + proplists:get_value(password, Opts, undefined), IoCb, Name, + Instr, PromptInfos, Opts, NumPrompts). + +keyboard_interact_get_responses(_, undefined, Password, _, _, _, _, _, + 1) when Password =/= undefined -> + [Password]; %% Password auth implemented with keyboard-interaction and passwd is known +keyboard_interact_get_responses(_, _, _, _, _, _, _, _, 0) -> + [""]; +keyboard_interact_get_responses(false, undefined, undefined, _, _, _, [Prompt|_], Opts, _) -> + ssh_no_io:read_line(Prompt, Opts); %% Throws error as keyboard interaction is not allowed +keyboard_interact_get_responses(true, undefined, _,IoCb, Name, Instr, PromptInfos, Opts, _) -> + keyboard_interact(IoCb, Name, Instr, PromptInfos, Opts); +keyboard_interact_get_responses(true, Fun, _, Name, Instr, PromptInfos, _, _, NumPrompts) -> + keyboard_interact_fun(Fun, Name, Instr, PromptInfos, NumPrompts). keyboard_interact(IoCb, Name, Instr, Prompts, Opts) -> if Name /= "" -> IoCb:format("~s", [Name]); @@ -404,10 +467,21 @@ keyboard_interact(IoCb, Name, Instr, Prompts, Opts) -> end, Prompts). -other_alg('ssh-rsa') -> - 'ssh-dss'; -other_alg('ssh-dss') -> - 'ssh-rsa'. +keyboard_interact_fun(KbdInteractFun, Name, Instr, PromptInfos, NumPrompts) -> + Prompts = lists:map(fun({Prompt, _Echo}) -> Prompt end, + PromptInfos), + case KbdInteractFun(Name, Instr, Prompts) of + Rs when length(Rs) == NumPrompts -> + Rs; + Rs -> + throw({mismatching_number_of_responses, + {got,Rs}, + {expected, NumPrompts}, + #ssh_msg_disconnect{code = ?SSH_DISCONNECT_SERVICE_NOT_AVAILABLE, + description = "User interaction failed", + language = "en"}}) + end. + decode_public_key_v2(<<?UINT32(Len0), _:Len0/binary, ?UINT32(Len1), BinE:Len1/binary, ?UINT32(Len2), BinN:Len2/binary>> |