diff options
Diffstat (limited to 'lib/ssh/src/ssh_auth.erl')
| -rw-r--r-- | lib/ssh/src/ssh_auth.erl | 194 |
1 files changed, 133 insertions, 61 deletions
diff --git a/lib/ssh/src/ssh_auth.erl b/lib/ssh/src/ssh_auth.erl index 45c4d52d7e..020fb06530 100644 --- a/lib/ssh/src/ssh_auth.erl +++ b/lib/ssh/src/ssh_auth.erl @@ -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 ]). %%-------------------------------------------------------------------- @@ -115,33 +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), - 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; + + + 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, @@ -185,7 +169,8 @@ 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 -> @@ -194,7 +179,7 @@ handle_userauth_request(#ssh_msg_userauth_request{user = User, false -> {not_authorized, {User, {error,"Bad user or password"}}, ssh_transport:ssh_packet(#ssh_msg_userauth_failure{ - authentications = "", + authentications = Methods, partial_success = false}, Ssh)} end; @@ -207,7 +192,7 @@ 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 +201,7 @@ 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 +217,9 @@ 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 +234,7 @@ 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 -> @@ -259,6 +246,65 @@ 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}}, @@ -280,6 +326,42 @@ 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 = <<?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) -> throw(#ssh_msg_disconnect{code = ?SSH_DISCONNECT_SERVICE_NOT_AVAILABLE, @@ -287,20 +369,20 @@ 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) -> - [{"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, []} + ], + Algs). user_name(Opts) -> Env = case os:type() of @@ -418,27 +500,17 @@ 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>> + ?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(_, _) -> |