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comparison: util/sasl/digest-md5.lua
util/sasl/digest-md5.lua
- branch
- sasl
- changeset 2182
- 1112871916eb
- child 2184
- 1fd38975addd
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| 2181:e92339c48ee6 | 2182:1112871916eb |
|---|---|
| 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 | |
| 15 --========================= | |
| 16 --SASL DIGEST-MD5 according to RFC 2831 | |
| 17 local function sasl_mechanism_digest_md5(self, message) | |
| 18 --TODO complete support for authzid | |
| 19 | |
| 20 local function serialize(message) | |
| 21 local data = "" | |
| 22 | |
| 23 if type(message) ~= "table" then error("serialize needs an argument of type table.") end | |
| 24 | |
| 25 -- testing all possible values | |
| 26 if message["realm"] then data = data..[[realm="]]..message.realm..[[",]] end | |
| 27 if message["nonce"] then data = data..[[nonce="]]..message.nonce..[[",]] end | |
| 28 if message["qop"] then data = data..[[qop="]]..message.qop..[[",]] end | |
| 29 if message["charset"] then data = data..[[charset=]]..message.charset.."," end | |
| 30 if message["algorithm"] then data = data..[[algorithm=]]..message.algorithm.."," end | |
| 31 if message["rspauth"] then data = data..[[rspauth=]]..message.rspauth.."," end | |
| 32 data = data:gsub(",$", "") | |
| 33 return data | |
| 34 end | |
| 35 | |
| 36 local function utf8tolatin1ifpossible(passwd) | |
| 37 local i = 1; | |
| 38 while i <= #passwd do | |
| 39 local passwd_i = to_byte(passwd:sub(i, i)); | |
| 40 if passwd_i > 0x7F then | |
| 41 if passwd_i < 0xC0 or passwd_i > 0xC3 then | |
| 42 return passwd; | |
| 43 end | |
| 44 i = i + 1; | |
| 45 passwd_i = to_byte(passwd:sub(i, i)); | |
| 46 if passwd_i < 0x80 or passwd_i > 0xBF then | |
| 47 return passwd; | |
| 48 end | |
| 49 end | |
| 50 i = i + 1; | |
| 51 end | |
| 52 | |
| 53 local p = {}; | |
| 54 local j = 0; | |
| 55 i = 1; | |
| 56 while (i <= #passwd) do | |
| 57 local passwd_i = to_byte(passwd:sub(i, i)); | |
| 58 if passwd_i > 0x7F then | |
| 59 i = i + 1; | |
| 60 local passwd_i_1 = to_byte(passwd:sub(i, i)); | |
| 61 t_insert(p, to_char(passwd_i%4*64 + passwd_i_1%64)); -- I'm so clever | |
| 62 else | |
| 63 t_insert(p, to_char(passwd_i)); | |
| 64 end | |
| 65 i = i + 1; | |
| 66 end | |
| 67 return t_concat(p); | |
| 68 end | |
| 69 local function latin1toutf8(str) | |
| 70 local p = {}; | |
| 71 for ch in gmatch(str, ".") do | |
| 72 ch = to_byte(ch); | |
| 73 if (ch < 0x80) then | |
| 74 t_insert(p, to_char(ch)); | |
| 75 elseif (ch < 0xC0) then | |
| 76 t_insert(p, to_char(0xC2, ch)); | |
| 77 else | |
| 78 t_insert(p, to_char(0xC3, ch - 64)); | |
| 79 end | |
| 80 end | |
| 81 return t_concat(p); | |
| 82 end | |
| 83 local function parse(data) | |
| 84 local message = {} | |
| 85 for k, v in gmatch(data, [[([%w%-]+)="?([^",]*)"?,?]]) do -- FIXME The hacky regex makes me shudder | |
| 86 message[k] = v; | |
| 87 end | |
| 88 return message; | |
| 89 end | |
| 90 | |
| 91 if not self.nonce then | |
| 92 self.nonce = generate_uuid(); | |
| 93 self.step = 0; | |
| 94 self.nonce_count = {}; | |
| 95 end | |
| 96 | |
| 97 self.step = self.step + 1; | |
| 98 if (self.step == 1) then | |
| 99 local challenge = serialize({ nonce = object.nonce, | |
| 100 qop = "auth", | |
| 101 charset = "utf-8", | |
| 102 algorithm = "md5-sess", | |
| 103 realm = self.realm}); | |
| 104 return "challenge", challenge; | |
| 105 elseif (self.step == 2) then | |
| 106 local response = parse(message); | |
| 107 -- check for replay attack | |
| 108 if response["nc"] then | |
| 109 if self.nonce_count[response["nc"]] then return "failure", "not-authorized" end | |
| 110 end | |
| 111 | |
| 112 -- check for username, it's REQUIRED by RFC 2831 | |
| 113 if not response["username"] then | |
| 114 return "failure", "malformed-request"; | |
| 115 end | |
| 116 self["username"] = response["username"]; | |
| 117 | |
| 118 -- check for nonce, ... | |
| 119 if not response["nonce"] then | |
| 120 return "failure", "malformed-request"; | |
| 121 else | |
| 122 -- check if it's the right nonce | |
| 123 if response["nonce"] ~= tostring(self.nonce) then return "failure", "malformed-request" end | |
| 124 end | |
| 125 | |
| 126 if not response["cnonce"] then return "failure", "malformed-request", "Missing entry for cnonce in SASL message." end | |
| 127 if not response["qop"] then response["qop"] = "auth" end | |
| 128 | |
| 129 if response["realm"] == nil or response["realm"] == "" then | |
| 130 response["realm"] = ""; | |
| 131 elseif response["realm"] ~= self.realm then | |
| 132 return "failure", "not-authorized", "Incorrect realm value"; | |
| 133 end | |
| 134 | |
| 135 local decoder; | |
| 136 if response["charset"] == nil then | |
| 137 decoder = utf8tolatin1ifpossible; | |
| 138 elseif response["charset"] ~= "utf-8" then | |
| 139 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."; | |
| 140 end | |
| 141 | |
| 142 local domain = ""; | |
| 143 local protocol = ""; | |
| 144 if response["digest-uri"] then | |
| 145 protocol, domain = response["digest-uri"]:match("(%w+)/(.*)$"); | |
| 146 if protocol == nil or domain == nil then return "failure", "malformed-request" end | |
| 147 else | |
| 148 return "failure", "malformed-request", "Missing entry for digest-uri in SASL message." | |
| 149 end | |
| 150 | |
| 151 --TODO maybe realm support | |
| 152 self.username = response["username"]; | |
| 153 local password_encoding, Y = self.credentials_handler("DIGEST-MD5", response["username"], self.realm, response["realm"], decoder); | |
| 154 if Y == nil then return "failure", "not-authorized" | |
| 155 elseif Y == false then return "failure", "account-disabled" end | |
| 156 local A1 = ""; | |
| 157 if response.authzid then | |
| 158 if response.authzid == self.username.."@"..self.realm then | |
| 159 -- COMPAT | |
| 160 log("warn", "Client is violating XMPP RFC. See section 6.1 of RFC 3920."); | |
| 161 A1 = Y..":"..response["nonce"]..":"..response["cnonce"]..":"..response.authzid; | |
| 162 else | |
| 163 A1 = "?"; | |
| 164 end | |
| 165 else | |
| 166 A1 = Y..":"..response["nonce"]..":"..response["cnonce"]; | |
| 167 end | |
| 168 local A2 = "AUTHENTICATE:"..protocol.."/"..domain; | |
| 169 | |
| 170 local HA1 = md5(A1, true); | |
| 171 local HA2 = md5(A2, true); | |
| 172 | |
| 173 local KD = HA1..":"..response["nonce"]..":"..response["nc"]..":"..response["cnonce"]..":"..response["qop"]..":"..HA2; | |
| 174 local response_value = md5(KD, true); | |
| 175 | |
| 176 if response_value == response["response"] then | |
| 177 -- calculate rspauth | |
| 178 A2 = ":"..protocol.."/"..domain; | |
| 179 | |
| 180 HA1 = md5(A1, true); | |
| 181 HA2 = md5(A2, true); | |
| 182 | |
| 183 KD = HA1..":"..response["nonce"]..":"..response["nc"]..":"..response["cnonce"]..":"..response["qop"]..":"..HA2 | |
| 184 local rspauth = md5(KD, true); | |
| 185 self.authenticated = true; | |
| 186 return "challenge", serialize({rspauth = rspauth}); | |
| 187 else | |
| 188 return "failure", "not-authorized", "The response provided by the client doesn't match the one we calculated." | |
| 189 end | |
| 190 elseif self.step == 3 then | |
| 191 if self.authenticated ~= nil then return "success" | |
| 192 else return "failure", "malformed-request" end | |
| 193 end | |
| 194 end |
