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author | Erlang/OTP <[email protected]> | 2009-11-20 14:54:40 +0000 |
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committer | Erlang/OTP <[email protected]> | 2009-11-20 14:54:40 +0000 |
commit | 84adefa331c4159d432d22840663c38f155cd4c1 (patch) | |
tree | bff9a9c66adda4df2106dfd0e5c053ab182a12bd /lib/ssh/src/ssh_auth.erl | |
download | otp-84adefa331c4159d432d22840663c38f155cd4c1.tar.gz otp-84adefa331c4159d432d22840663c38f155cd4c1.tar.bz2 otp-84adefa331c4159d432d22840663c38f155cd4c1.zip |
The R13B03 release.OTP_R13B03
Diffstat (limited to 'lib/ssh/src/ssh_auth.erl')
-rw-r--r-- | lib/ssh/src/ssh_auth.erl | 423 |
1 files changed, 423 insertions, 0 deletions
diff --git a/lib/ssh/src/ssh_auth.erl b/lib/ssh/src/ssh_auth.erl new file mode 100644 index 0000000000..aa74528544 --- /dev/null +++ b/lib/ssh/src/ssh_auth.erl @@ -0,0 +1,423 @@ +%% +%% %CopyrightBegin% +%% +%% Copyright Ericsson AB 2008-2009. 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/. +%% +%% 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. +%% +%% %CopyrightEnd% +%% + +%% + +-module(ssh_auth). + +-include("ssh.hrl"). + +-include("ssh_auth.hrl"). +-include("ssh_transport.hrl"). + +-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, + userauth_messages/0 + ]). + +%%-------------------------------------------------------------------- +%%% Internal application API +%%-------------------------------------------------------------------- +publickey_msg([Cb, #ssh{user = User, + session_id = SessionId, + service = Service, + opts = Opts} = Ssh]) -> + ssh_bits:install_messages(userauth_pk_messages()), + Alg = Cb:alg_name(), + case ssh_file:private_identity_key(Alg, Opts) of + {ok, PrivKey} -> + PubKeyBlob = ssh_file:encode_public_key(PrivKey), + SigData = build_sig_data(SessionId, + User, Service, Alg, PubKeyBlob), + Sig = Cb:sign(PrivKey, SigData), + SigBlob = list_to_binary([?string(Alg), ?binary(Sig)]), + ssh_transport:ssh_packet( + #ssh_msg_userauth_request{user = User, + service = Service, + method = "publickey", + data = [?TRUE, + ?string(Alg), + ?binary(PubKeyBlob), + ?binary(SigBlob)]}, + Ssh); + _Error -> + not_ok + end. + +password_msg([#ssh{opts = Opts, io_cb = IoCb, + user = User, service = Service} = Ssh]) -> + ssh_bits:install_messages(userauth_passwd_messages()), + Password = case proplists:get_value(password, Opts) of + undefined -> + IoCb:read_password("ssh password: "); + PW -> + PW + end, + ssh_transport:ssh_packet( + #ssh_msg_userauth_request{user = User, + service = Service, + method = "password", + data = + <<?BOOLEAN(?FALSE), + ?STRING(list_to_binary(Password))>>}, + Ssh). + +%% See RFC 4256 for info on keyboard-interactive +keyboard_interactive_msg([#ssh{user = User, + service = Service} = Ssh]) -> + ssh_bits:install_messages(userauth_keyboard_interactive_messages()), + ssh_transport:ssh_packet( + #ssh_msg_userauth_request{user = User, + service = Service, + method = "keyboard-interactive", + data = << ?STRING(<<"">>), + ?STRING(<<>>) >> }, + Ssh). + +service_request_msg(Ssh) -> + ssh_transport:ssh_packet(#ssh_msg_service_request{name = "ssh-userauth"}, + Ssh#ssh{service = "ssh-userauth"}). + +init_userauth_request_msg(#ssh{opts = Opts} = Ssh) -> + case user_name(Opts) of + {ok, User} -> + Msg = #ssh_msg_userauth_request{user = User, + service = "ssh-connection", + method = "none", + data = <<>>}, + CbFirst = proplists:get_value(public_key_alg, Opts, + ?PREFERRED_PK_ALG), + CbSecond = other_cb(CbFirst), + AllowUserInt = proplists:get_value(allow_user_interaction, Opts, + true), + Prefs = method_preference(CbFirst, CbSecond, AllowUserInt), + 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, + description = ErrStr, + language = "en"}) + end. + +userauth_request_msg(#ssh{userauth_preference = []} = Ssh) -> + Msg = #ssh_msg_disconnect{code = + ?SSH_DISCONNECT_NO_MORE_AUTH_METHODS_AVAILABLE, + description = "Unable to connect using the available" + " authentication methods", + language = "en"}, + {disconnect, Msg, ssh_transport:ssh_packet(Msg, Ssh)}; + +userauth_request_msg(#ssh{userauth_methods = Methods, + userauth_preference = [{Pref, Module, + Function, Args} | Prefs]} + = Ssh0) -> + Ssh = Ssh0#ssh{userauth_preference = Prefs}, + case lists:member(Pref, Methods) of + true -> + case Module:Function(Args ++ [Ssh]) of + not_ok -> + userauth_request_msg(Ssh); + Result -> + Result + end; + false -> + userauth_request_msg(Ssh) + end. + + +handle_userauth_request(#ssh_msg_service_request{name = + Name = "ssh-userauth"}, + _, Ssh) -> + {ok, ssh_transport:ssh_packet(#ssh_msg_service_accept{name = Name}, + Ssh#ssh{service = "ssh-connection"})}; + +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), + + 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}}, + ssh_transport:ssh_packet(#ssh_msg_userauth_failure{ + authentications = "", + partial_success = false}, Ssh)} + end; + +handle_userauth_request(#ssh_msg_userauth_request{user = User, + service = "ssh-connection", + method = "none"}, _, + #ssh{userauth_supported_methods = Methods} = Ssh) -> + {not_authorized, {User, undefined}, + 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 = "publickey", + data = Data}, + SessionId, #ssh{opts = Opts} = Ssh) -> + <<?BYTE(HaveSig), ?UINT32(ALen), BAlg:ALen/binary, + ?UINT32(KLen), KeyBlob:KLen/binary, SigWLen/binary>> = Data, + Alg = binary_to_list(BAlg), + case HaveSig of + ?TRUE -> + case verify_sig(SessionId, User, "ssh-connection", Alg, + KeyBlob, SigWLen, Opts) of + ok -> + {authorized, User, + ssh_transport:ssh_packet( + #ssh_msg_userauth_success{}, Ssh)}; + {error, Reason} -> + {not_authorized, {User, {error, Reason}}, + ssh_transport:ssh_packet(#ssh_msg_userauth_failure{ + authentications="publickey,password", + partial_success = false}, Ssh)} + end; + ?FALSE -> + ssh_bits:install_messages(userauth_pk_messages()), + {not_authorized, {User, undefined}, + ssh_transport:ssh_packet( + #ssh_msg_userauth_pk_ok{algorithm_name = Alg, + key_blob = KeyBlob}, Ssh)} + 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}}, + ssh_transport:ssh_packet( + #ssh_msg_userauth_failure{authentications = Methods, + partial_success = false}, Ssh)}. + +handle_userauth_info_request( + #ssh_msg_userauth_info_request{name = Name, + instruction = Instr, + num_prompts = NumPrompts, + data = Data}, IoCb, + #ssh{opts = Opts} = Ssh) -> + PromptInfos = decode_keyboard_interactive_prompts(NumPrompts,Data), + Resps = keyboard_interact_get_responses(IoCb, Opts, + Name, Instr, PromptInfos), + %%?dbg(true, "keyboard_interactive_reply: resps=~n#~p ~n", [Resps]), + 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)}. + +handle_userauth_info_response(#ssh_msg_userauth_info_response{}, + _Auth) -> + throw(#ssh_msg_disconnect{code = ?SSH_DISCONNECT_SERVICE_NOT_AVAILABLE, + description = "Server does not support" + "keyboard-interactive", + language = "en"}). +userauth_messages() -> + [ {ssh_msg_userauth_request, ?SSH_MSG_USERAUTH_REQUEST, + [string, + string, + string, + '...']}, + + {ssh_msg_userauth_failure, ?SSH_MSG_USERAUTH_FAILURE, + [string, + boolean]}, + + {ssh_msg_userauth_success, ?SSH_MSG_USERAUTH_SUCCESS, + []}, + + {ssh_msg_userauth_banner, ?SSH_MSG_USERAUTH_BANNER, + [string, + string]}]. +%%-------------------------------------------------------------------- +%%% Internal functions +%%-------------------------------------------------------------------- +method_preference(Callback1, Callback2, true) -> + [{"publickey", ?MODULE, publickey_msg, [Callback1]}, + {"publickey", ?MODULE, publickey_msg,[Callback2]}, + {"password", ?MODULE, password_msg, []}, + {"keyboard-interactive", ?MODULE, keyboard_interactive_msg, []} + ]; +method_preference(Callback1, Callback2, false) -> + [{"publickey", ?MODULE, publickey_msg, [Callback1]}, + {"publickey", ?MODULE, publickey_msg,[Callback2]}, + {"password", ?MODULE, password_msg, []} + ]. + +user_name(Opts) -> + Env = case os:type() of + {win32, _} -> + "USERNAME"; + {unix, _} -> + "LOGNAME" + end, + case proplists:get_value(user, Opts, os:getenv(Env)) of + false -> + case os:getenv("USER") of + false -> + {error, no_user}; + User -> + {ok, User} + end; + User -> + {ok, User} + end. + +check_password(User, Password, Opts) -> + %%?dbg(true, " ~p ~p ~p ~n", [User, Password, Opts]), + case proplists:get_value(pwdfun, Opts) of + undefined -> + Static = get_password_option(Opts, User), + Password == Static; + Cheker -> + Cheker(User, Password) + end. + +get_password_option(Opts, User) -> + Passwords = proplists:get_value(user_passwords, Opts, []), + case lists:keysearch(User, 1, Passwords) of + {value, {User, Pw}} -> Pw; + false -> proplists:get_value(password, Opts, false) + end. + +verify_sig(SessionId, User, Service, Alg, KeyBlob, SigWLen, Opts) -> + case ssh_file:lookup_user_key(User, Alg, Opts) of + {ok, OurKey} -> + {ok, Key} = ssh_file:decode_public_key_v2(KeyBlob, Alg), + case OurKey of + Key -> + NewSig = build_sig_data(SessionId, + User, Service, Alg, KeyBlob), + <<?UINT32(AlgSigLen), AlgSig:AlgSigLen/binary>> = SigWLen, + <<?UINT32(AlgLen), _Alg:AlgLen/binary, + ?UINT32(SigLen), Sig:SigLen/binary>> = AlgSig, + M = alg_to_module(Alg), + M:verify(OurKey, NewSig, Sig); + _ -> + {error, key_unacceptable} + end; + Error -> Error + end. + +build_sig_data(SessionId, User, Service, Alg, KeyBlob) -> + Sig = [?binary(SessionId), + ?SSH_MSG_USERAUTH_REQUEST, + ?string(User), + ?string(Service), + ?binary(<<"publickey">>), + ?TRUE, + ?string(Alg), + ?binary(KeyBlob)], + list_to_binary(Sig). + +decode_keyboard_interactive_prompts(NumPrompts, Data) -> + Types = lists:append(lists:duplicate(NumPrompts, [string, boolean])), + pairwise_tuplify(ssh_bits:decode(Data, Types)). + +pairwise_tuplify([E1, E2 | Rest]) -> [{E1, E2} | pairwise_tuplify(Rest)]; +pairwise_tuplify([]) -> []. + + +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); + PW -> [PW] + end; + undefined -> + keyboard_interact(IoCb, Name, Instr, PromptInfos); + 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(IoCb, Name, Instr, Prompts) -> + if Name /= "" -> IoCb:format("~s", [Name]); + true -> ok + end, + if Instr /= "" -> IoCb:format("~s", [Instr]); + true -> ok + end, + lists:map(fun({Prompt, true}) -> IoCb:read_line(Prompt); + ({Prompt, false}) -> IoCb:read_password(Prompt) + end, + Prompts). + +userauth_passwd_messages() -> + [ + {ssh_msg_userauth_passwd_changereq, ?SSH_MSG_USERAUTH_PASSWD_CHANGEREQ, + [string, + string]} + ]. + +userauth_keyboard_interactive_messages() -> + [ {ssh_msg_userauth_info_request, ?SSH_MSG_USERAUTH_INFO_REQUEST, + [string, + string, + string, + uint32, + '...']}, + + {ssh_msg_userauth_info_response, ?SSH_MSG_USERAUTH_INFO_RESPONSE, + [uint32, + '...']} + ]. + +userauth_pk_messages() -> + [ {ssh_msg_userauth_pk_ok, ?SSH_MSG_USERAUTH_PK_OK, + [string, % algorithm name + binary]} % key blob + ]. + +alg_to_module("ssh-dss") -> + ssh_dsa; +alg_to_module("ssh-rsa") -> + ssh_rsa. + +other_cb(ssh_rsa) -> + ssh_dsa; +other_cb(ssh_dsa) -> + ssh_rsa. |