diff options
Diffstat (limited to 'lib/ssh/src/ssh_auth.erl')
| -rw-r--r-- | lib/ssh/src/ssh_auth.erl | 320 |
1 files changed, 203 insertions, 117 deletions
diff --git a/lib/ssh/src/ssh_auth.erl b/lib/ssh/src/ssh_auth.erl index 1fa3df847f..a91b8c200e 100644 --- a/lib/ssh/src/ssh_auth.erl +++ b/lib/ssh/src/ssh_auth.erl @@ -1,18 +1,19 @@ %% %% %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 -%% compliance with the License. You should have received a copy of the -%% Erlang Public License along with this software. If not, it can be -%% retrieved online at http://www.erlang.org/. +%% Licensed under the Apache License, Version 2.0 (the "License"); +%% you may not use this file except in compliance with the License. +%% You may obtain a copy of the License at %% -%% Software distributed under the License is distributed on an "AS IS" -%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See -%% the License for the specific language governing rights and limitations -%% under the License. +%% http://www.apache.org/licenses/LICENSE-2.0 +%% +%% Unless required by applicable law or agreed to in writing, software +%% distributed under the License is distributed on an "AS IS" BASIS, +%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +%% See the License for the specific language governing permissions and +%% limitations under the License. %% %% %CopyrightEnd% %% @@ -30,7 +31,8 @@ -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 ]). %%-------------------------------------------------------------------- @@ -83,7 +85,7 @@ password_msg([#ssh{opts = Opts, io_cb = IoCb, method = "password", data = <<?BOOLEAN(?FALSE), - ?STRING(list_to_binary(Password))>>}, + ?STRING(unicode:characters_to_binary(Password))>>}, Ssh) end. @@ -115,36 +117,16 @@ 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, @@ -187,24 +169,44 @@ handle_userauth_request(#ssh_msg_service_request{name = handle_userauth_request(#ssh_msg_userauth_request{user = User, service = "ssh-connection", method = "password", - data = Data}, _, - #ssh{opts = Opts} = Ssh) -> - <<_:8, ?UINT32(Sz), BinPwd:Sz/binary>> = Data, - Password = binary_to_list(BinPwd), - + data = <<?FALSE, ?UINT32(Sz), BinPwd:Sz/binary>>}, _, + #ssh{opts = Opts, + userauth_supported_methods = Methods} = Ssh) -> + Password = unicode:characters_to_list(BinPwd), case check_password(User, Password, Opts) of true -> {authorized, User, ssh_transport:ssh_packet(#ssh_msg_userauth_success{}, Ssh)}; false -> - {not_authorized, {User, {passwd, Password}}, + {not_authorized, {User, {error,"Bad user or password"}}, ssh_transport:ssh_packet(#ssh_msg_userauth_failure{ - authentications = "", + authentications = Methods, partial_success = false}, Ssh)} end; 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{userauth_supported_methods = Methods} = 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 = Methods, + 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}, @@ -216,7 +218,9 @@ handle_userauth_request(#ssh_msg_userauth_request{user = User, service = "ssh-connection", method = "publickey", data = Data}, - SessionId, #ssh{opts = Opts} = Ssh) -> + SessionId, + #ssh{opts = Opts, + userauth_supported_methods = Methods} = Ssh) -> <<?BYTE(HaveSig), ?UINT32(ALen), BAlg:ALen/binary, ?UINT32(KLen), KeyBlob:KLen/binary, SigWLen/binary>> = Data, Alg = binary_to_list(BAlg), @@ -229,9 +233,9 @@ handle_userauth_request(#ssh_msg_userauth_request{user = User, ssh_transport:ssh_packet( #ssh_msg_userauth_success{}, Ssh)}; false -> - {not_authorized, {User, {error, "Invalid signature"}}, + {not_authorized, {User, undefined}, ssh_transport:ssh_packet(#ssh_msg_userauth_failure{ - authentications="publickey,password", + authentications = Methods, partial_success = false}, Ssh)} end; ?FALSE -> @@ -243,6 +247,65 @@ 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, + kb_tries_left = KbTriesLeft, + userauth_supported_methods = Methods} = Ssh) -> + case KbTriesLeft of + N when N<1 -> + {not_authorized, {User, {authmethod, "keyboard-interactive"}}, + ssh_transport:ssh_packet( + #ssh_msg_userauth_failure{authentications = Methods, + partial_success = false}, 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++"\"", + "password: ", + 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, + kb_data = Msg + })} + end; + +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}}, @@ -257,15 +320,48 @@ 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 = Opts, + kb_tries_left = KbTriesLeft0, + kb_data = InfoMsg, + user = User, + userauth_supported_methods = Methods} = Ssh) -> + KbTriesLeft = KbTriesLeft0 - 1, + 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 KbTriesLeft > 0 -> + UserAuthInfoMsg = + InfoMsg#ssh_msg_userauth_info_request{ + name = "", + instruction = + lists:concat( + ["Bad user or password, try again. ", + integer_to_list(KbTriesLeft), + " tries left."]) + }, + {not_authorized, {User, undefined}, + ssh_transport:ssh_packet(UserAuthInfoMsg, + Ssh#ssh{kb_tries_left = KbTriesLeft})}; + + false -> + {not_authorized, {User, {error,"Bad user or password"}}, + ssh_transport:ssh_packet(#ssh_msg_userauth_failure{ + authentications = Methods, + partial_success = false}, + Ssh#ssh{kb_data = undefined, + kb_tries_left = 0} + )} + end; handle_userauth_info_response(#ssh_msg_userauth_info_response{}, _Auth) -> @@ -274,29 +370,20 @@ 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 @@ -352,7 +439,7 @@ verify_sig(SessionId, User, Service, Alg, KeyBlob, SigWLen, Opts) -> build_sig_data(SessionId, User, Service, KeyBlob, Alg) -> Sig = [?binary(SessionId), ?SSH_MSG_USERAUTH_REQUEST, - ?string(User), + ?string_utf8(User), ?string(Service), ?binary(<<"publickey">>), ?TRUE, @@ -363,35 +450,29 @@ 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]); @@ -405,27 +486,32 @@ 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>> + ?UINT32(Len1), E:Len1/big-signed-integer-unit:8, + ?UINT32(Len2), N:Len2/big-signed-integer-unit:8>> ,"ssh-rsa") -> - E = ssh_bits:erlint(Len1, BinE), - N = ssh_bits:erlint(Len2, BinN), {ok, #'RSAPublicKey'{publicExponent = E, modulus = N}}; decode_public_key_v2(<<?UINT32(Len0), _:Len0/binary, - ?UINT32(Len1), BinP:Len1/binary, - ?UINT32(Len2), BinQ:Len2/binary, - ?UINT32(Len3), BinG:Len3/binary, - ?UINT32(Len4), BinY:Len4/binary>> + ?UINT32(Len1), P:Len1/big-signed-integer-unit:8, + ?UINT32(Len2), Q:Len2/big-signed-integer-unit:8, + ?UINT32(Len3), G:Len3/big-signed-integer-unit:8, + ?UINT32(Len4), Y:Len4/big-signed-integer-unit:8>> , "ssh-dss") -> - P = ssh_bits:erlint(Len1, BinP), - Q = ssh_bits:erlint(Len2, BinQ), - G = ssh_bits:erlint(Len3, BinG), - Y = ssh_bits:erlint(Len4, BinY), {ok, {Y, #'Dss-Parms'{p = P, q = Q, g = G}}}; decode_public_key_v2(_, _) -> |