./ct_report/coverage/cyrsasl_digest.COVER.html

1 %%%----------------------------------------------------------------------
2 %%% File : cyrsasl_digest.erl
3 %%% Author : Alexey Shchepin <alexey@sevcom.net>
4 %%% Purpose : DIGEST-MD5 SASL mechanism
5 %%% Created : 11 Mar 2003 by Alexey Shchepin <alexey@sevcom.net>
6 %%%
7 %%%
8 %%% ejabberd, Copyright (C) 2002-2011 ProcessOne
9 %%%
10 %%% This program is free software; you can redistribute it and/or
11 %%% modify it under the terms of the GNU General Public License as
12 %%% published by the Free Software Foundation; either version 2 of the
13 %%% License, or (at your option) any later version.
14 %%%
15 %%% This program is distributed in the hope that it will be useful,
16 %%% but WITHOUT ANY WARRANTY; without even the implied warranty of
17 %%% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 %%% General Public License for more details.
19 %%%
20 %%% You should have received a copy of the GNU General Public License
21 %%% along with this program; if not, write to the Free Software
22 %%% Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 %%%
24 %%%----------------------------------------------------------------------
25
26 -module(cyrsasl_digest).
27 -author('alexey@sevcom.net').
28
29 -export([mechanism/0,
30 mech_new/3,
31 mech_step/2]).
32
33 -ignore_xref([mech_new/3]).
34
35 -deprecated({'_', '_', next_major_release}).
36
37 -include("mongoose.hrl").
38
39 -behaviour(cyrsasl).
40
41 -record(state, {step :: integer(),
42 nonce :: binary(),
43 username :: jid:user() | undefined,
44 authzid,
45 auth_module :: ejabberd_auth:authmodule(),
46 host :: jid:server(),
47 creds :: mongoose_credentials:t()
48 }).
49
50 -type state() :: #state{}.
51
52 -spec mechanism() -> cyrsasl:mechanism().
53 mechanism() ->
54 6 <<"DIGEST-MD5">>.
55
56 -spec mech_new(Host :: jid:server(),
57 Creds :: mongoose_credentials:t(),
58 Socket :: term()) -> {ok, state()}.
59 mech_new(Host, Creds, _Socket) ->
60 2 Text = <<"The DIGEST-MD5 authentication mechanism is deprecated and "
61 " will be removed in the next release, please consider using"
62 " any of the SCRAM-SHA methods or equivalent instead.">>,
63 2 mongoose_deprecations:log(
64 {?MODULE, ?FUNCTION_NAME, ?FUNCTION_ARITY},
65 #{what => sasl_digest_md5_deprecated, text => Text},
66 [{log_level, warning}]),
67 2 {ok, #state{step = 1,
68 nonce = mongoose_bin:gen_from_crypto(),
69 host = Host,
70 creds = Creds}}.
71
72 -spec mech_step(State :: tuple(), ClientIn :: any()) -> R when
73 R :: {ok, mongoose_credentials:t()}
74 | cyrsasl:error().
75 mech_step(#state{step = 1, nonce = Nonce} = State, _) ->
76 2 {continue,
77 <<"nonce=\"", Nonce/binary, "\",qop=\"auth\",charset=utf-8,algorithm=md5-sess">>,
78 State#state{step = 3}};
79 mech_step(#state{step = 3, nonce = Nonce} = State, ClientIn) ->
80 2 case parse(ClientIn) of
81 bad ->
82 
:-(
 {error, <<"bad-protocol">>};
83 KeyVals ->
84 2 authorize_if_uri_valid(State, KeyVals, Nonce)
85 end;
86 mech_step(#state{step = 5,
87 auth_module = AuthModule,
88 username = UserName,
89 authzid = AuthzId,
90 creds = Creds}, <<>>) ->
91 1 {ok, mongoose_credentials:extend(Creds, [{username, UserName},
92 {authzid, AuthzId},
93 {auth_module, AuthModule}])};
94 mech_step(State, Msg) ->
95 
:-(
 ?LOG_DEBUG(#{what => sasl_digest_error_bad_protocol, sasl_state => State, message => Msg}),
96 
:-(
 {error, <<"bad-protocol">>}.
97
98
99 authorize_if_uri_valid(State, KeyVals, Nonce) ->
100 2 UserName = xml:get_attr_s(<<"username">>, KeyVals),
101 2 DigestURI = xml:get_attr_s(<<"digest-uri">>, KeyVals),
102 2 case is_digesturi_valid(DigestURI, State#state.host) of
103 false ->
104 
:-(
 ?LOG_DEBUG(#{what => unauthorized_login, reason => invalid_digest_uri,
105 
:-(
 message => DigestURI, user => UserName}),
106 
:-(
 {error, <<"not-authorized">>, UserName};
107 true ->
108 2 maybe_authorize(UserName, KeyVals, Nonce, State)
109 end.
110
111 maybe_authorize(UserName, KeyVals, Nonce, State) ->
112 2 AuthzId = xml:get_attr_s(<<"authzid">>, KeyVals),
113 2 LServer = mongoose_credentials:lserver(State#state.creds),
114 2 HostType = mongoose_credentials:host_type(State#state.creds),
115 2 JID = jid:make_bare(UserName, LServer),
116 2 case ejabberd_auth:get_passterm_with_authmodule(HostType, JID) of
117 false ->
118 1 {error, <<"not-authorized">>, UserName};
119 {Passwd, AuthModule} ->
120 1 DigestGen = fun(PW) -> response(KeyVals, UserName, PW, Nonce, AuthzId,
121 <<"AUTHENTICATE">>)
122 end,
123 1 ExtraCreds = [{username, UserName},
124 {password, <<>>},
125 {digest, xml:get_attr_s(<<"response">>, KeyVals)},
126 {digest_gen, DigestGen}],
127 1 Request = mongoose_credentials:extend(State#state.creds, ExtraCreds),
128 1 do_authorize(UserName, KeyVals, Nonce, Passwd, Request, AuthzId, AuthModule, State)
129 end.
130
131 do_authorize(UserName, KeyVals, Nonce, Passwd, Request, AuthzId, AuthModule, State) ->
132 1 case ejabberd_auth:authorize(Request) of
133 {ok, Result} ->
134 1 RspAuth = response(KeyVals,
135 UserName, Passwd,
136 Nonce, AuthzId, <<>>),
137 1 {continue,
138 list_to_binary([<<"rspauth=">>, RspAuth]),
139 State#state{step = 5,
140 auth_module = AuthModule,
141 username = UserName,
142 authzid = AuthzId,
143 creds = Result}};
144 {error, not_authorized} ->
145 
:-(
 {error, <<"not-authorized">>, UserName}
146 end.
147
148 -spec parse(binary()) -> 'bad' | [{binary(), binary()}].
149 parse(S) ->
150 2 parse1(S, <<>>, []).
151
152 parse1(<<$=, Cs/binary>>, S, Ts) ->
153 22 parse2(Cs, binary_reverse(S), <<>>, Ts);
154 parse1(<<$,, Cs/binary>>, <<>>, Ts) ->
155 
:-(
 parse1(Cs, <<>>, Ts);
156 parse1(<<$\s, Cs/binary>>, <<>>, Ts) ->
157 
:-(
 parse1(Cs, <<>>, Ts);
158 parse1(<<C, Cs/binary>>, S, Ts) ->
159 138 parse1(Cs, <<C, S/binary>>, Ts);
160 parse1(<<>>, <<>>, T) ->
161 2 lists:reverse(T);
162 parse1(<<>>, _S, _T) ->
163 
:-(
 bad.
164
165 parse2(<<$\", Cs/binary>>, Key, Val, Ts) ->
166 22 parse3(Cs, Key, Val, Ts);
167 parse2(<<C, Cs/binary>>, Key, Val, Ts) ->
168 
:-(
 parse4(Cs, Key, <<C, Val/binary>>, Ts);
169 parse2(<<>>, _, _, _) ->
170 
:-(
 bad.
171
172 parse3(<<$\", Cs/binary>>, Key, Val, Ts) ->
173 22 parse4(Cs, Key, Val, Ts);
174 parse3(<<$\\, C, Cs/binary>>, Key, Val, Ts) ->
175 
:-(
 parse3(Cs, Key, <<C, Val/binary>>, Ts);
176 parse3(<<C, Cs/binary>>, Key, Val, Ts) ->
177 389 parse3(Cs, Key, <<C, Val/binary>>, Ts);
178 parse3(<<>>, _, _, _) ->
179 
:-(
 bad.
180
181 -spec parse4(binary(),
182 Key :: binary(),
183 Val :: binary(),
184 Ts :: [{binary(), binary()}]) -> 'bad' | [{K :: binary(), V :: binary()}].
185 parse4(<<$,, Cs/binary>>, Key, Val, Ts) ->
186 20 parse1(Cs, <<>>, [{Key, binary_reverse(Val)} | Ts]);
187 parse4(<<$\s, Cs/binary>>, Key, Val, Ts) ->
188 
:-(
 parse4(Cs, Key, Val, Ts);
189 parse4(<<C, Cs/binary>>, Key, Val, Ts) ->
190 
:-(
 parse4(Cs, Key, <<C, Val/binary>>, Ts);
191 parse4(<<>>, Key, Val, Ts) ->
192 2 parse1(<<>>, <<>>, [{Key, binary_reverse(Val)} | Ts]).
193
194 binary_reverse(<<>>) ->
195 50 <<>>;
196 binary_reverse(<<H, T/binary>>) ->
197 719 <<(binary_reverse(T))/binary, H>>.
198
199 %% @doc Check if the digest-uri is valid.
200 %% RFC-2831 allows to provide the IP address in Host,
201 %% however ejabberd doesn't allow that.
202 %% If the service (for example jabber.example.org)
203 %% is provided by several hosts (being one of them server3.example.org),
204 %% then digest-uri can be like xmpp/server3.example.org/jabber.example.org
205 %% In that case, ejabberd only checks the service name, not the host.
206 -spec is_digesturi_valid(DigestURICase :: binary(),
207 JabberHost :: 'undefined' | jid:server()) -> boolean().
208 is_digesturi_valid(DigestURICase, JabberHost) ->
209 2 DigestURI = jid:str_tolower(DigestURICase),
210 2 case catch binary:split(DigestURI, <<"/">>) of
211 [<<"xmpp">>, Host] when Host == JabberHost ->
212 2 true;
213 [<<"xmpp">>, _Host, ServName] when ServName == JabberHost ->
214 
:-(
 true;
215 _ ->
216 
:-(
 false
217 end.
218
219
220 -spec digit_to_xchar(byte()) -> char().
221 digit_to_xchar(D) when (D >= 0) and (D < 10) ->
222 130 D + 48;
223 digit_to_xchar(D) ->
224 62 D + 87.
225
226 -spec hex(binary()) -> binary().
227 hex(S) ->
228 6 hex(S, <<>>).
229
230 -spec hex(binary(), binary()) -> binary().
231 hex(<<>>, Res) ->
232 6 binary_reverse(Res);
233 hex(<<N, Ns/binary>>, Res) ->
234 96 D1 = digit_to_xchar(N rem 16),
235 96 D2 = digit_to_xchar(N div 16),
236 96 hex(Ns, <<D1, D2, Res/binary>>).
237
238
239 -spec response(KeyVals :: [{binary(), binary()}],
240 User :: jid:user(),
241 Passwd :: binary(),
242 Nonce :: binary(),
243 AuthzId :: binary(),
244 A2Prefix :: <<_:_*96>>) -> binary().
245 response(KeyVals, User, Passwd, Nonce, AuthzId, A2Prefix) ->
246 2 Realm = xml:get_attr_s(<<"realm">>, KeyVals),
247 2 CNonce = xml:get_attr_s(<<"cnonce">>, KeyVals),
248 2 DigestURI = xml:get_attr_s(<<"digest-uri">>, KeyVals),
249 2 NC = xml:get_attr_s(<<"nc">>, KeyVals),
250 2 QOP = xml:get_attr_s(<<"qop">>, KeyVals),
251 2 A1 = case AuthzId of
252 <<>> ->
253 
:-(
 list_to_binary(
254 [crypto:hash(md5, [User, <<":">>, Realm, <<":">>, Passwd]),
255 <<":">>, Nonce, <<":">>, CNonce]);
256 _ ->
257 2 list_to_binary(
258 [crypto:hash(md5, [User, <<":">>, Realm, <<":">>, Passwd]),
259 <<":">>, Nonce, <<":">>, CNonce, <<":">>, AuthzId])
260 end,
261 2 A2 = case QOP of
262 <<"auth">> ->
263 2 [A2Prefix, <<":">>, DigestURI];
264 _ ->
265 
:-(
 [A2Prefix, <<":">>, DigestURI,
266 <<":00000000000000000000000000000000">>]
267 end,
268 2 T = [hex(crypto:hash(md5, A1)), <<":">>, Nonce, <<":">>,
269 NC, <<":">>, CNonce, <<":">>, QOP, <<":">>,
270 hex(crypto:hash(md5, A2))],
271 2 hex(crypto:hash(md5, T)).
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