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authorErlang/OTP <[email protected]>2015-06-01 12:06:33 +0200
committerErlang/OTP <[email protected]>2015-06-01 12:06:33 +0200
commit1de75380804938117b198bed4cfa42ce85b8143b (patch)
treed2a1ae638bee640d2da48116ac22b70fb70448a5 /lib/ssh/src
parent27e0d318073323dc39f234607e02a56a54b2f80f (diff)
parent3f600aa0048b6515616774f0a289a88cb66affbe (diff)
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Merge branch 'hans/ssh/codenomicon_degradation/OTP-12784' into maint-17
* hans/ssh/codenomicon_degradation/OTP-12784: ssh: update ssh version ssh: Plain text message returned for invalid version exchange ssh: Implement keyboard_interactive on server side ssh: Check e and f parameters in kexdh ssh: Set max num algoritms in msg_kexinit negotiation
Diffstat (limited to 'lib/ssh/src')
-rw-r--r--lib/ssh/src/ssh.erl9
-rw-r--r--lib/ssh/src/ssh_auth.erl80
-rw-r--r--lib/ssh/src/ssh_connection_handler.erl32
-rw-r--r--lib/ssh/src/ssh_transport.erl59
4 files changed, 151 insertions, 29 deletions
diff --git a/lib/ssh/src/ssh.erl b/lib/ssh/src/ssh.erl
index 71e7d77475..7ed17618e7 100644
--- a/lib/ssh/src/ssh.erl
+++ b/lib/ssh/src/ssh.erl
@@ -331,6 +331,8 @@ handle_option([{exec, _} = Opt | Rest], SocketOptions, SshOptions) ->
handle_option(Rest, SocketOptions, [handle_ssh_option(Opt) | SshOptions]);
handle_option([{auth_methods, _} = Opt | Rest], SocketOptions, SshOptions) ->
handle_option(Rest, SocketOptions, [handle_ssh_option(Opt) | SshOptions]);
+handle_option([{auth_method_kb_interactive_data, _} = Opt | Rest], SocketOptions, SshOptions) ->
+ handle_option(Rest, SocketOptions, [handle_ssh_option(Opt) | SshOptions]);
handle_option([{pref_public_key_algs, _} = Opt | Rest], SocketOptions, SshOptions) ->
handle_option(Rest, SocketOptions, [handle_ssh_option(Opt) | SshOptions]);
handle_option([{quiet_mode, _} = Opt|Rest], SocketOptions, SshOptions) ->
@@ -411,6 +413,13 @@ handle_ssh_option({exec, Function} = Opt) when is_function(Function) ->
Opt;
handle_ssh_option({auth_methods, Value} = Opt) when is_list(Value) ->
Opt;
+handle_ssh_option({auth_method_kb_interactive_data, {Name,Instruction,Prompt,Echo}} = Opt) when is_list(Name),
+ is_list(Instruction),
+ is_list(Prompt),
+ is_boolean(Echo) ->
+ Opt;
+handle_ssh_option({auth_method_kb_interactive_data, F} = Opt) when is_function(F,3) ->
+ Opt;
handle_ssh_option({infofun, Value} = Opt) when is_function(Value) ->
Opt;
handle_ssh_option({connectfun, Value} = Opt) when is_function(Value) ->
diff --git a/lib/ssh/src/ssh_auth.erl b/lib/ssh/src/ssh_auth.erl
index 45c4d52d7e..9d1ab14ce9 100644
--- a/lib/ssh/src/ssh_auth.erl
+++ b/lib/ssh/src/ssh_auth.erl
@@ -259,6 +259,54 @@ 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}},
@@ -280,6 +328,38 @@ 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 = 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) ->
throw(#ssh_msg_disconnect{code = ?SSH_DISCONNECT_SERVICE_NOT_AVAILABLE,
diff --git a/lib/ssh/src/ssh_connection_handler.erl b/lib/ssh/src/ssh_connection_handler.erl
index d4bbb0b32e..f751094211 100644
--- a/lib/ssh/src/ssh_connection_handler.erl
+++ b/lib/ssh/src/ssh_connection_handler.erl
@@ -339,13 +339,12 @@ hello({info_line, _Line},#state{role = client, socket = Socket} = State) ->
inet:setopts(Socket, [{active, once}]),
{next_state, hello, State};
-hello({info_line, _Line},#state{role = server} = State) ->
- DisconnectMsg =
- #ssh_msg_disconnect{code =
- ?SSH_DISCONNECT_PROTOCOL_ERROR,
- description = "Did not receive expected protocol version exchange",
- language = "en"},
- handle_disconnect(DisconnectMsg, State);
+hello({info_line, _Line},#state{role = server,
+ socket = Socket,
+ transport_cb = Transport } = State) ->
+ %% as openssh
+ Transport:send(Socket, "Protocol mismatch."),
+ {stop, {shutdown,"Protocol mismatch in version exchange."}, State};
hello({version_exchange, Version}, #state{ssh_params = Ssh0,
socket = Socket,
@@ -500,10 +499,21 @@ userauth(#ssh_msg_userauth_info_request{} = Msg,
{next_state, userauth, next_packet(State#state{ssh_params = Ssh})};
userauth(#ssh_msg_userauth_info_response{} = Msg,
- #state{ssh_params = #ssh{role = server} = Ssh0} = State) ->
- {ok, {Reply, Ssh}} = ssh_auth:handle_userauth_info_response(Msg, Ssh0),
- send_msg(Reply, State),
- {next_state, userauth, next_packet(State#state{ssh_params = Ssh})};
+ #state{ssh_params = #ssh{role = server,
+ peer = {_, Address}} = Ssh0,
+ opts = Opts, starter = Pid} = State) ->
+ case ssh_auth:handle_userauth_info_response(Msg, Ssh0) of
+ {authorized, User, {Reply, Ssh}} ->
+ send_msg(Reply, State),
+ Pid ! ssh_connected,
+ connected_fun(User, Address, "keyboard-interactive", Opts),
+ {next_state, connected,
+ next_packet(State#state{auth_user = User, ssh_params = Ssh})};
+ {not_authorized, {User, Reason}, {Reply, Ssh}} ->
+ retry_fun(User, Address, Reason, Opts),
+ send_msg(Reply, State),
+ {next_state, userauth, next_packet(State#state{ssh_params = Ssh})}
+ end;
userauth(#ssh_msg_userauth_success{}, #state{ssh_params = #ssh{role = client} = Ssh,
starter = Pid} = State) ->
diff --git a/lib/ssh/src/ssh_transport.erl b/lib/ssh/src/ssh_transport.erl
index 8669be570e..6c0873fd9e 100644
--- a/lib/ssh/src/ssh_transport.erl
+++ b/lib/ssh/src/ssh_transport.erl
@@ -240,20 +240,30 @@ key_exchange_first_msg('diffie-hellman-group-exchange-sha1', Ssh0) ->
handle_kexdh_init(#ssh_msg_kexdh_init{e = E}, Ssh0) ->
{G, P} = dh_group1(),
- {Private, Public} = dh_gen_key(G, P, 1024),
- K = ssh_math:ipow(E, Private, P),
- Key = get_host_key(Ssh0),
- H = kex_h(Ssh0, Key, E, Public, K),
- H_SIG = sign_host_key(Ssh0, Key, H),
- {SshPacket, Ssh1} = ssh_packet(#ssh_msg_kexdh_reply{public_host_key = Key,
- f = Public,
- h_sig = H_SIG
- }, Ssh0),
-
- {ok, SshPacket, Ssh1#ssh{keyex_key = {{Private, Public}, {G, P}},
- shared_secret = K,
- exchanged_hash = H,
- session_id = sid(Ssh1, H)}}.
+ if
+ 1=<E, E=<(P-1) ->
+ {Private, Public} = dh_gen_key(G, P, 1024),
+ K = ssh_math:ipow(E, Private, P),
+ Key = get_host_key(Ssh0),
+ H = kex_h(Ssh0, Key, E, Public, K),
+ H_SIG = sign_host_key(Ssh0, Key, H),
+ {SshPacket, Ssh1} = ssh_packet(#ssh_msg_kexdh_reply{public_host_key = Key,
+ f = Public,
+ h_sig = H_SIG
+ }, Ssh0),
+
+ {ok, SshPacket, Ssh1#ssh{keyex_key = {{Private, Public}, {G, P}},
+ shared_secret = K,
+ exchanged_hash = H,
+ session_id = sid(Ssh1, H)}};
+ true ->
+ Error = {error,bad_e_from_peer},
+ Disconnect = #ssh_msg_disconnect{
+ code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED,
+ description = "Key exchange failed, 'f' out of bounds",
+ language = "en"},
+ throw({Error, Disconnect})
+ end.
handle_kex_dh_gex_group(#ssh_msg_kex_dh_gex_group{p = P, g = G}, Ssh0) ->
{Private, Public} = dh_gen_key(G,P,1024),
@@ -277,7 +287,7 @@ handle_new_keys(#ssh_msg_newkeys{}, Ssh0) ->
%% %% Select algorithms
handle_kexdh_reply(#ssh_msg_kexdh_reply{public_host_key = HostKey, f = F,
h_sig = H_SIG},
- #ssh{keyex_key = {{Private, Public}, {_G, P}}} = Ssh0) ->
+ #ssh{keyex_key = {{Private, Public}, {_G, P}}} = Ssh0) when 1=<F, F=<(P-1)->
K = ssh_math:ipow(F, Private, P),
H = kex_h(Ssh0, HostKey, Public, F, K),
@@ -293,7 +303,15 @@ handle_kexdh_reply(#ssh_msg_kexdh_reply{public_host_key = HostKey, f = F,
description = "Key exchange failed",
language = "en"},
throw({Error, Disconnect})
- end.
+ end;
+handle_kexdh_reply(#ssh_msg_kexdh_reply{}, _SSH) ->
+ Error = {error,bad_f_from_peer},
+ Disconnect = #ssh_msg_disconnect{
+ code = ?SSH_DISCONNECT_KEY_EXCHANGE_FAILED,
+ description = "Key exchange failed, 'f' out of bounds",
+ language = "en"},
+ throw({Error, Disconnect}).
+
handle_kex_dh_gex_request(#ssh_msg_kex_dh_gex_request{min = _Min,
n = _NBits,
@@ -519,10 +537,15 @@ alg_final(SSH0) ->
{ok,SSH6} = decompress_final(SSH5),
SSH6.
-select_all(CL, SL) ->
+select_all(CL, SL) when length(CL) + length(SL) < 50 ->
A = CL -- SL, %% algortihms only used by client
%% algorithms used by client and server (client pref)
- lists:map(fun(ALG) -> list_to_atom(ALG) end, (CL -- A)).
+ lists:map(fun(ALG) -> list_to_atom(ALG) end, (CL -- A));
+select_all(_CL, _SL) ->
+ throw(#ssh_msg_disconnect{code = ?SSH_DISCONNECT_PROTOCOL_ERROR,
+ description = "Too many algorithms",
+ language = "en"}).
+
select([], []) ->
none;