diff options
Diffstat (limited to 'lib/ssh/src/ssh_auth.erl')
| -rw-r--r-- | lib/ssh/src/ssh_auth.erl | 367 |
1 files changed, 183 insertions, 184 deletions
diff --git a/lib/ssh/src/ssh_auth.erl b/lib/ssh/src/ssh_auth.erl index 9d1ab14ce9..fdbb5c152a 100644 --- a/lib/ssh/src/ssh_auth.erl +++ b/lib/ssh/src/ssh_auth.erl @@ -3,16 +3,17 @@ %% %% 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% %% @@ -40,27 +41,29 @@ publickey_msg([Alg, #ssh{user = User, session_id = SessionId, service = Service, opts = Opts} = Ssh]) -> - Hash = sha, %% Maybe option?! KeyCb = proplists:get_value(key_cb, Opts, ssh_file), - case KeyCb:user_key(Alg, Opts) of - {ok, Key} -> - StrAlgo = algorithm_string(Alg), - PubKeyBlob = encode_public_key(Key), - SigData = build_sig_data(SessionId, - User, Service, PubKeyBlob, StrAlgo), - Sig = ssh_transport:sign(SigData, Hash, Key), - SigBlob = list_to_binary([?string(StrAlgo), ?binary(Sig)]), - ssh_transport:ssh_packet( - #ssh_msg_userauth_request{user = User, - service = Service, - method = "publickey", - data = [?TRUE, - ?string(StrAlgo), - ?binary(PubKeyBlob), - ?binary(SigBlob)]}, - Ssh); + {ok, PrivKey} -> + StrAlgo = atom_to_list(Alg), + case encode_public_key(StrAlgo, ssh_transport:extract_public_key(PrivKey)) of + not_ok -> + not_ok; + PubKeyBlob -> + SigData = build_sig_data(SessionId, + User, Service, PubKeyBlob, StrAlgo), + Sig = ssh_transport:sign(SigData, Hash, PrivKey), + SigBlob = list_to_binary([?string(StrAlgo), ?binary(Sig)]), + ssh_transport:ssh_packet( + #ssh_msg_userauth_request{user = User, + service = Service, + method = "publickey", + data = [?TRUE, + ?string(StrAlgo), + ?binary(PubKeyBlob), + ?binary(SigBlob)]}, + Ssh) + end; _Error -> not_ok end. @@ -115,33 +118,21 @@ 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), - Prefs = method_preference(FirstAlg, SecondAlg), - 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), - Prefs = method_preference(FirstAlg, SecondAlg), - ssh_transport:ssh_packet(Msg, Ssh#ssh{user = User, - userauth_preference = Prefs, - userauth_methods = none, - service = "ssh-connection"}); - _ -> - Prefs = method_preference(FirstAlg), - ssh_transport:ssh_packet(Msg, Ssh#ssh{user = User, - userauth_preference = Prefs, - userauth_methods = none, - service = "ssh-connection"}) - end - end; + Algs0 = proplists:get_value(pref_public_key_algs, Opts, ?SUPPORTED_USER_KEYS), + %% The following line is not strictly correct. The call returns the + %% supported HOST key types while we are interested in USER keys. However, + %% they "happens" to be the same (for now). This could change.... + %% There is no danger as long as the set of user keys is a subset of the set + %% of host keys. + CryptoSupported = ssh_transport:supported_algorithms(public_key), + Algs = [A || A <- Algs0, + lists:member(A, CryptoSupported)], + + 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, @@ -168,7 +159,7 @@ userauth_request_msg(#ssh{userauth_methods = Methods, not_ok -> userauth_request_msg(Ssh); Result -> - Result + {Pref,Result} end; false -> userauth_request_msg(Ssh) @@ -185,17 +176,18 @@ handle_userauth_request(#ssh_msg_userauth_request{user = User, service = "ssh-connection", method = "password", data = <<?FALSE, ?UINT32(Sz), BinPwd:Sz/binary>>}, _, - #ssh{opts = Opts} = Ssh) -> + #ssh{opts = Opts, + userauth_supported_methods = Methods} = Ssh) -> Password = unicode:characters_to_list(BinPwd), - case check_password(User, Password, Opts) of - true -> + case check_password(User, Password, Opts, Ssh) of + {true,Ssh1} -> {authorized, User, - ssh_transport:ssh_packet(#ssh_msg_userauth_success{}, Ssh)}; - false -> + ssh_transport:ssh_packet(#ssh_msg_userauth_success{}, Ssh1)}; + {false,Ssh1} -> {not_authorized, {User, {error,"Bad user or password"}}, ssh_transport:ssh_packet(#ssh_msg_userauth_failure{ - authentications = "", - partial_success = false}, Ssh)} + authentications = Methods, + partial_success = false}, Ssh1)} end; handle_userauth_request(#ssh_msg_userauth_request{user = User, @@ -207,7 +199,7 @@ handle_userauth_request(#ssh_msg_userauth_request{user = User, %% ?UINT32(Sz2), NewBinPwd:Sz2/binary >> }, _, - Ssh) -> + #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 @@ -216,7 +208,7 @@ handle_userauth_request(#ssh_msg_userauth_request{user = User, {not_authorized, {User, {error,"Password change not supported"}}, ssh_transport:ssh_packet(#ssh_msg_userauth_failure{ - authentications = "", + authentications = Methods, partial_success = false}, Ssh)}; handle_userauth_request(#ssh_msg_userauth_request{user = User, @@ -232,7 +224,9 @@ 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), @@ -247,7 +241,7 @@ handle_userauth_request(#ssh_msg_userauth_request{user = User, false -> {not_authorized, {User, undefined}, ssh_transport:ssh_packet(#ssh_msg_userauth_failure{ - authentications="publickey,password", + authentications = Methods, partial_success = false}, Ssh)} end; ?FALSE -> @@ -261,49 +255,59 @@ 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] - })}; + _, #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 + })} + end; handle_userauth_request(#ssh_msg_userauth_request{user = User, service = "ssh-connection", @@ -314,6 +318,8 @@ handle_userauth_request(#ssh_msg_userauth_request{user = User, #ssh_msg_userauth_failure{authentications = Methods, partial_success = false}, Ssh)}. + + handle_userauth_info_request( #ssh_msg_userauth_info_request{name = Name, instruction = Instr, @@ -330,33 +336,20 @@ handle_userauth_info_request( 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 -> + #ssh{opts = Opts, + kb_tries_left = KbTriesLeft, + user = User, + userauth_supported_methods = Methods} = Ssh) -> + case check_password(User, unicode:characters_to_list(Password), Opts, Ssh) of + {true,Ssh1} -> {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 -> + ssh_transport:ssh_packet(#ssh_msg_userauth_success{}, Ssh1)}; + {false,Ssh1} -> {not_authorized, {User, {error,"Bad user or password"}}, ssh_transport:ssh_packet(#ssh_msg_userauth_failure{ - authentications = "", + authentications = Methods, partial_success = false}, - Ssh#ssh{opts = lists:keydelete(kb_userauth_info_msg,1,Opts)} + Ssh1#ssh{kb_tries_left = max(KbTriesLeft-1, 0)} )} end; @@ -367,20 +360,23 @@ handle_userauth_info_response(#ssh_msg_userauth_info_response{}, "keyboard-interactive", language = "en"}). + %%-------------------------------------------------------------------- %%% Internal functions %%-------------------------------------------------------------------- -method_preference(Alg1, Alg2) -> - [{"publickey", ?MODULE, publickey_msg, [Alg1]}, - {"publickey", ?MODULE, publickey_msg,[Alg2]}, - {"password", ?MODULE, password_msg, []}, - {"keyboard-interactive", ?MODULE, keyboard_interactive_msg, []} - ]. -method_preference(Alg1) -> - [{"publickey", ?MODULE, publickey_msg, [Alg1]}, - {"password", ?MODULE, password_msg, []}, - {"keyboard-interactive", ?MODULE, keyboard_interactive_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, []}, + {"keyboard-interactive", ?MODULE, keyboard_interactive_msg, []}, + {"keyboard-interactive", ?MODULE, keyboard_interactive_msg, []}, + {"keyboard-interactive", ?MODULE, keyboard_interactive_msg, []}, + {"keyboard-interactive", ?MODULE, keyboard_interactive_msg, []}, + {"keyboard-interactive", ?MODULE, keyboard_interactive_msg, []} + ], + Algs). user_name(Opts) -> Env = case os:type() of @@ -401,13 +397,34 @@ user_name(Opts) -> {ok, User} end. -check_password(User, Password, Opts) -> +check_password(User, Password, Opts, Ssh) -> case proplists:get_value(pwdfun, Opts) of undefined -> Static = get_password_option(Opts, User), - Password == Static; - Cheker -> - Cheker(User, Password) + {Password == Static, Ssh}; + + Checker when is_function(Checker,2) -> + {Checker(User, Password), Ssh}; + + Checker when is_function(Checker,4) -> + #ssh{pwdfun_user_state = PrivateState, + peer = {_,PeerAddr={_,_}} + } = Ssh, + case Checker(User, Password, PeerAddr, PrivateState) of + true -> + {true,Ssh}; + false -> + {false,Ssh}; + {true,NewState} -> + {true, Ssh#ssh{pwdfun_user_state=NewState}}; + {false,NewState} -> + {false, Ssh#ssh{pwdfun_user_state=NewState}}; + disconnect -> + throw(#ssh_msg_disconnect{code = ?SSH_DISCONNECT_SERVICE_NOT_AVAILABLE, + description = + "Unable to connect using the available authentication methods", + language = ""}) + end end. get_password_option(Opts, User) -> @@ -444,10 +461,7 @@ build_sig_data(SessionId, User, Service, KeyBlob, Alg) -> ?binary(KeyBlob)], list_to_binary(Sig). -algorithm_string('ssh-rsa') -> - "ssh-rsa"; -algorithm_string('ssh-dss') -> - "ssh-dss". + decode_keyboard_interactive_prompts(_NumPrompts, Data) -> ssh_message:decode_keyboard_interactive_prompts(Data, []). @@ -468,14 +482,14 @@ keyboard_interact_get_responses(false, undefined, undefined, _, _, _, [Prompt|_] 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_get_responses(true, Fun, _Pwd, _IoCb, Name, Instr, PromptInfos, _Opts, NumPrompts) -> keyboard_interact_fun(Fun, Name, Instr, PromptInfos, NumPrompts). keyboard_interact(IoCb, Name, Instr, Prompts, Opts) -> - if Name /= "" -> IoCb:format("~s", [Name]); + if Name /= "" -> IoCb:format("~s~n", [Name]); true -> ok end, - if Instr /= "" -> IoCb:format("~s", [Instr]); + if Instr /= "" -> IoCb:format("~s~n", [Instr]); true -> ok end, lists:map(fun({Prompt, true}) -> IoCb:read_line(Prompt, Opts); @@ -498,33 +512,18 @@ keyboard_interact_fun(KbdInteractFun, Name, Instr, PromptInfos, NumPrompts) -> language = "en"}}) end. -other_alg('ssh-rsa') -> - 'ssh-dss'; -other_alg('ssh-dss') -> - 'ssh-rsa'. -decode_public_key_v2(<<?UINT32(Len0), _:Len0/binary, - ?UINT32(Len1), BinE:Len1/binary, - ?UINT32(Len2), BinN:Len2/binary>> - ,"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>> - , "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(_, _) -> - {error, bad_format}. - -encode_public_key(#'RSAPrivateKey'{publicExponent = E, modulus = N}) -> - ssh_bits:encode(["ssh-rsa",E,N], [string,mpint,mpint]); -encode_public_key(#'DSAPrivateKey'{p = P, q = Q, g = G, y = Y}) -> - ssh_bits:encode(["ssh-dss",P,Q,G,Y], [string,mpint,mpint,mpint,mpint]). +decode_public_key_v2(Bin, _Type) -> + try + public_key:ssh_decode(Bin, ssh2_pubkey) + of + Key -> {ok, Key} + catch + _:_ -> {error, bad_format} + end. + +encode_public_key(_Alg, Key) -> + try + public_key:ssh_encode(Key, ssh2_pubkey) + catch + _:_ -> not_ok + end. |