2 -- Copyright (C) 2008-2009 Tobias Markmann
4 -- All rights reserved.
6 -- Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
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.
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.
14 local tostring = tostring;
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;
23 local md5 = require "util.hashes".md5;
24 local log = require "util.logger".init("sasl");
25 local generate_uuid = require "util.uuid".generate;
29 --=========================
30 --SASL DIGEST-MD5 according to RFC 2831
31 local function digest_response()
33 return response, A1, A2
36 local function digest(self, message)
37 --TODO complete support for authzid
39 local function serialize(message)
42 if type(message) ~= "table" then error("serialize needs an argument of type table.") end
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(",$", "")
55 local function utf8tolatin1ifpossible(passwd)
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
64 passwd_i = to_byte(passwd:sub(i, i));
65 if passwd_i < 0x80 or passwd_i > 0xBF then
75 while (i <= #passwd) do
76 local passwd_i = to_byte(passwd:sub(i, i));
77 if passwd_i > 0x7F then
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
82 t_insert(p, to_char(passwd_i));
88 local function latin1toutf8(str)
90 for ch in s_gmatch(str, ".") do
93 t_insert(p, to_char(ch));
94 elseif (ch < 0xC0) then
95 t_insert(p, to_char(0xC2, ch));
97 t_insert(p, to_char(0xC3, ch - 64));
102 local function parse(data)
104 for k, v in s_gmatch(data, [[([%w%-]+)="?([^",]*)"?,?]]) do -- FIXME The hacky regex makes me shudder
110 if not self.nonce then
111 self.nonce = generate_uuid();
113 self.nonce_count = {};
116 self.step = self.step + 1;
117 if (self.step == 1) then
118 local challenge = serialize({ nonce = self.nonce,
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
131 -- check for username, it's REQUIRED by RFC 2831
132 if not response["username"] then
133 return "failure", "malformed-request";
135 self["username"] = response["username"];
137 -- check for nonce, ...
138 if not response["nonce"] then
139 return "failure", "malformed-request";
141 -- check if it's the right nonce
142 if response["nonce"] ~= tostring(self.nonce) then return "failure", "malformed-request" end
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
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";
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.";
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
167 return "failure", "malformed-request", "Missing entry for digest-uri in SASL message."
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
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
188 if response.authzid then
189 if response.authzid == self.username or response.authzid == self.username.."@"..self.realm then
191 log("warn", "Client is violating RFC 3920 (section 6.1, point 7).");
192 A1 = Y..":"..response["nonce"]..":"..response["cnonce"]..":"..response.authzid;
194 return "failure", "invalid-authzid";
197 A1 = Y..":"..response["nonce"]..":"..response["cnonce"];
199 local A2 = "AUTHENTICATE:"..protocol.."/"..domain;
201 local HA1 = md5(A1, true);
202 local HA2 = md5(A2, true);
204 local KD = HA1..":"..response["nonce"]..":"..response["nc"]..":"..response["cnonce"]..":"..response["qop"]..":"..HA2;
205 local response_value = md5(KD, true);
207 if response_value == response["response"] then
209 A2 = ":"..protocol.."/"..domain;
214 KD = HA1..":"..response["nonce"]..":"..response["nc"]..":"..response["cnonce"]..":"..response["qop"]..":"..HA2
215 local rspauth = md5(KD, true);
216 self.authenticated = true;
217 return "success", serialize({rspauth = rspauth});
219 return "failure", "not-authorized", "The response provided by the client doesn't match the one we calculated."
221 elseif self.step == 3 then
222 if self.authenticated ~= nil then return "success"
223 else return "failure", "malformed-request" end
227 function init(registerMechanism)
228 registerMechanism("DIGEST-MD5", {"plain"}, digest);