prosody
8fbbdb11a520
util/sasl/digest-md5.lua

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util/sasl/digest-md5.lua @ 2193:8fbbdb11a520

Merge with sasl branch.
author Tobias Markmann <tm@ayena.de>
date Mon, 16 Nov 2009 21:43:57 +0100
parent 2192:fa46d158c95f
child 2206:5f54100bb426
comparison
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2080:ca419b92a8c7 2193:8fbbdb11a520
1 -- sasl.lua v0.4
2 -- Copyright (C) 2008-2009 Tobias Markmann
3 --
4 -- All rights reserved.
5 --
6 -- Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
7 --
8 -- * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
9 -- * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
10 -- * Neither the name of Tobias Markmann nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.
11 --
12 -- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
13
14 local tostring = tostring;
15 local type = type;
16
17 local s_gmatch = string.gmatch;
18 local s_match = string.match;
19 local t_concat = table.concat;
20 local t_insert = table.insert;
21 local to_byte, to_char = string.byte, string.char;
22
23 local md5 = require "util.hashes".md5;
24 local log = require "util.logger".init("sasl");
25 local generate_uuid = require "util.uuid".generate;
26
27 module "plain"
28
29 --=========================
30 --SASL DIGEST-MD5 according to RFC 2831
31 local function digest_response()
32
33 return response, A1, A2
34 end
35
36 local function digest(self, message)
37 --TODO complete support for authzid
38
39 local function serialize(message)
40 local data = ""
41
42 if type(message) ~= "table" then error("serialize needs an argument of type table.") end
43
44 -- testing all possible values
45 if message["realm"] then data = data..[[realm="]]..message.realm..[[",]] end
46 if message["nonce"] then data = data..[[nonce="]]..message.nonce..[[",]] end
47 if message["qop"] then data = data..[[qop="]]..message.qop..[[",]] end
48 if message["charset"] then data = data..[[charset=]]..message.charset.."," end
49 if message["algorithm"] then data = data..[[algorithm=]]..message.algorithm.."," end
50 if message["rspauth"] then data = data..[[rspauth=]]..message.rspauth.."," end
51 data = data:gsub(",$", "")
52 return data
53 end
54
55 local function utf8tolatin1ifpossible(passwd)
56 local i = 1;
57 while i <= #passwd do
58 local passwd_i = to_byte(passwd:sub(i, i));
59 if passwd_i > 0x7F then
60 if passwd_i < 0xC0 or passwd_i > 0xC3 then
61 return passwd;
62 end
63 i = i + 1;
64 passwd_i = to_byte(passwd:sub(i, i));
65 if passwd_i < 0x80 or passwd_i > 0xBF then
66 return passwd;
67 end
68 end
69 i = i + 1;
70 end
71
72 local p = {};
73 local j = 0;
74 i = 1;
75 while (i <= #passwd) do
76 local passwd_i = to_byte(passwd:sub(i, i));
77 if passwd_i > 0x7F then
78 i = i + 1;
79 local passwd_i_1 = to_byte(passwd:sub(i, i));
80 t_insert(p, to_char(passwd_i%4*64 + passwd_i_1%64)); -- I'm so clever
81 else
82 t_insert(p, to_char(passwd_i));
83 end
84 i = i + 1;
85 end
86 return t_concat(p);
87 end
88 local function latin1toutf8(str)
89 local p = {};
90 for ch in s_gmatch(str, ".") do
91 ch = to_byte(ch);
92 if (ch < 0x80) then
93 t_insert(p, to_char(ch));
94 elseif (ch < 0xC0) then
95 t_insert(p, to_char(0xC2, ch));
96 else
97 t_insert(p, to_char(0xC3, ch - 64));
98 end
99 end
100 return t_concat(p);
101 end
102 local function parse(data)
103 local message = {}
104 for k, v in s_gmatch(data, [[([%w%-]+)="?([^",]*)"?,?]]) do -- FIXME The hacky regex makes me shudder
105 message[k] = v;
106 end
107 return message;
108 end
109
110 if not self.nonce then
111 self.nonce = generate_uuid();
112 self.step = 0;
113 self.nonce_count = {};
114 end
115
116 self.step = self.step + 1;
117 if (self.step == 1) then
118 local challenge = serialize({ nonce = self.nonce,
119 qop = "auth",
120 charset = "utf-8",
121 algorithm = "md5-sess",
122 realm = self.realm});
123 return "challenge", challenge;
124 elseif (self.step == 2) then
125 local response = parse(message);
126 -- check for replay attack
127 if response["nc"] then
128 if self.nonce_count[response["nc"]] then return "failure", "not-authorized" end
129 end
130
131 -- check for username, it's REQUIRED by RFC 2831
132 if not response["username"] then
133 return "failure", "malformed-request";
134 end
135 self["username"] = response["username"];
136
137 -- check for nonce, ...
138 if not response["nonce"] then
139 return "failure", "malformed-request";
140 else
141 -- check if it's the right nonce
142 if response["nonce"] ~= tostring(self.nonce) then return "failure", "malformed-request" end
143 end
144
145 if not response["cnonce"] then return "failure", "malformed-request", "Missing entry for cnonce in SASL message." end
146 if not response["qop"] then response["qop"] = "auth" end
147
148 if response["realm"] == nil or response["realm"] == "" then
149 response["realm"] = "";
150 elseif response["realm"] ~= self.realm then
151 return "failure", "not-authorized", "Incorrect realm value";
152 end
153
154 local decoder;
155 if response["charset"] == nil then
156 decoder = utf8tolatin1ifpossible;
157 elseif response["charset"] ~= "utf-8" then
158 return "failure", "incorrect-encoding", "The client's response uses "..response["charset"].." for encoding with isn't supported by sasl.lua. Supported encodings are latin or utf-8.";
159 end
160
161 local domain = "";
162 local protocol = "";
163 if response["digest-uri"] then
164 protocol, domain = response["digest-uri"]:match("(%w+)/(.*)$");
165 if protocol == nil or domain == nil then return "failure", "malformed-request" end
166 else
167 return "failure", "malformed-request", "Missing entry for digest-uri in SASL message."
168 end
169
170 --TODO maybe realm support
171 self.username = response["username"];
172 if self.profile.plain then
173 local password, state = self.profile.plain(response["username"], self.realm)
174 if state == nil then return "failure", "not-authorized"
175 elseif state == false then return "failure", "account-disabled" end
176 Y = md5(response["username"]..":"..response["realm"]..":"..password);
177 elseif self.profile["digest-md5"] then
178 local Y, state = self.profile["digest-md5"](response["username"], self.realm, response["realm"], response["charset"])
179 if state == nil then return "failure", "not-authorized"
180 elseif state == false then return "failure", "account-disabled" end
181 elseif self.profile["digest-md5-test"] then
182 -- TODO
183 end
184 --local password_encoding, Y = self.credentials_handler("DIGEST-MD5", response["username"], self.realm, response["realm"], decoder);
185 --if Y == nil then return "failure", "not-authorized"
186 --elseif Y == false then return "failure", "account-disabled" end
187 local A1 = "";
188 if response.authzid then
189 if response.authzid == self.username or response.authzid == self.username.."@"..self.realm then
190 -- COMPAT
191 log("warn", "Client is violating RFC 3920 (section 6.1, point 7).");
192 A1 = Y..":"..response["nonce"]..":"..response["cnonce"]..":"..response.authzid;
193 else
194 return "failure", "invalid-authzid";
195 end
196 else
197 A1 = Y..":"..response["nonce"]..":"..response["cnonce"];
198 end
199 local A2 = "AUTHENTICATE:"..protocol.."/"..domain;
200
201 local HA1 = md5(A1, true);
202 local HA2 = md5(A2, true);
203
204 local KD = HA1..":"..response["nonce"]..":"..response["nc"]..":"..response["cnonce"]..":"..response["qop"]..":"..HA2;
205 local response_value = md5(KD, true);
206
207 if response_value == response["response"] then
208 -- calculate rspauth
209 A2 = ":"..protocol.."/"..domain;
210
211 HA1 = md5(A1, true);
212 HA2 = md5(A2, true);
213
214 KD = HA1..":"..response["nonce"]..":"..response["nc"]..":"..response["cnonce"]..":"..response["qop"]..":"..HA2
215 local rspauth = md5(KD, true);
216 self.authenticated = true;
217 --TODO: considering sending the rspauth in a success node for saving one roundtrip; allowed according to http://tools.ietf.org/html/draft-saintandre-rfc3920bis-09#section-7.3.6
218 return "challenge", serialize({rspauth = rspauth});
219 else
220 return "failure", "not-authorized", "The response provided by the client doesn't match the one we calculated."
221 end
222 elseif self.step == 3 then
223 if self.authenticated ~= nil then return "success"
224 else return "failure", "malformed-request" end
225 end
226 end
227
228 function init(registerMechanism)
229 registerMechanism("DIGEST-MD5", {"plain"}, digest);
230 end
231
232 return _M;