1 -- sasl.lua v0.4 |
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2 -- Copyright (C) 2008-2009 Tobias Markmann |
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3 -- |
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4 -- All rights reserved. |
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5 -- |
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6 -- Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: |
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7 -- |
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8 -- * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. |
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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. |
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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. |
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11 -- |
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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. |
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13 |
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14 local cyrussasl = require "cyrussasl"; |
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15 local log = require "util.logger".init("sasl_cyrus"); |
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16 |
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17 local setmetatable = setmetatable |
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18 |
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19 local pcall = pcall |
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20 local s_match, s_gmatch = string.match, string.gmatch |
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21 |
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22 local sasl_errstring = { |
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23 -- SASL result codes -- |
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24 [1] = "another step is needed in authentication"; |
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25 [0] = "successful result"; |
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26 [-1] = "generic failure"; |
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27 [-2] = "memory shortage failure"; |
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28 [-3] = "overflowed buffer"; |
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29 [-4] = "mechanism not supported"; |
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30 [-5] = "bad protocol / cancel"; |
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31 [-6] = "can't request info until later in exchange"; |
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32 [-7] = "invalid parameter supplied"; |
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33 [-8] = "transient failure (e.g., weak key)"; |
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34 [-9] = "integrity check failed"; |
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35 [-12] = "SASL library not initialized"; |
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36 |
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37 -- client only codes -- |
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38 [2] = "needs user interaction"; |
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39 [-10] = "server failed mutual authentication step"; |
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40 [-11] = "mechanism doesn't support requested feature"; |
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41 |
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42 -- server only codes -- |
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43 [-13] = "authentication failure"; |
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44 [-14] = "authorization failure"; |
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45 [-15] = "mechanism too weak for this user"; |
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46 [-16] = "encryption needed to use mechanism"; |
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47 [-17] = "One time use of a plaintext password will enable requested mechanism for user"; |
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48 [-18] = "passphrase expired, has to be reset"; |
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49 [-19] = "account disabled"; |
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50 [-20] = "user not found"; |
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51 [-23] = "version mismatch with plug-in"; |
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52 [-24] = "remote authentication server unavailable"; |
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53 [-26] = "user exists, but no verifier for user"; |
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54 |
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55 -- codes for password setting -- |
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56 [-21] = "passphrase locked"; |
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57 [-22] = "requested change was not needed"; |
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58 [-27] = "passphrase is too weak for security policy"; |
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59 [-28] = "user supplied passwords not permitted"; |
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60 }; |
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61 setmetatable(sasl_errstring, { __index = function() return "undefined error!" end }); |
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62 |
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63 local _ENV = nil; |
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64 -- luacheck: std none |
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65 |
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66 local method = {}; |
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67 method.__index = method; |
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68 local initialized = false; |
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69 |
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70 local function init(service_name) |
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71 if not initialized then |
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72 local st, errmsg = pcall(cyrussasl.server_init, service_name); |
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73 if st then |
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74 initialized = true; |
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75 else |
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76 log("error", "Failed to initialize Cyrus SASL: %s", errmsg); |
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77 end |
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78 end |
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79 end |
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80 |
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81 -- create a new SASL object which can be used to authenticate clients |
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82 -- host_fqdn may be nil in which case gethostname() gives the value. |
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83 -- For GSSAPI, this determines the hostname in the service ticket (after |
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84 -- reverse DNS canonicalization, only if [libdefaults] rdns = true which |
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85 -- is the default). |
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86 local function new(realm, service_name, app_name, host_fqdn) |
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87 |
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88 init(app_name or service_name); |
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89 |
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90 local st, ret = pcall(cyrussasl.server_new, service_name, host_fqdn, realm, nil, nil) |
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91 if not st then |
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92 log("error", "Creating SASL server connection failed: %s", ret); |
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93 return nil; |
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94 end |
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95 |
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96 local sasl_i = { realm = realm, service_name = service_name, cyrus = ret }; |
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97 |
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98 if cyrussasl.set_canon_cb then |
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99 local c14n_cb = function (user) |
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100 local node = s_match(user, "^([^@]+)"); |
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101 log("debug", "Canonicalizing username %s to %s", user, node) |
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102 return node |
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103 end |
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104 cyrussasl.set_canon_cb(sasl_i.cyrus, c14n_cb); |
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105 end |
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106 |
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107 cyrussasl.setssf(sasl_i.cyrus, 0, 0xffffffff) |
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108 local mechanisms = {}; |
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109 local cyrus_mechs = cyrussasl.listmech(sasl_i.cyrus, nil, "", " ", ""); |
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110 for w in s_gmatch(cyrus_mechs, "[^ ]+") do |
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111 mechanisms[w] = true; |
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112 end |
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113 sasl_i.mechs = mechanisms; |
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114 return setmetatable(sasl_i, method); |
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115 end |
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116 |
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117 -- get a fresh clone with the same realm and service name |
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118 function method:clean_clone() |
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119 return new(self.realm, self.service_name) |
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120 end |
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121 |
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122 -- get a list of possible SASL mechanims to use |
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123 function method:mechanisms() |
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124 return self.mechs; |
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125 end |
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126 |
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127 -- select a mechanism to use |
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128 function method:select(mechanism) |
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129 if not self.selected and self.mechs[mechanism] then |
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130 self.selected = mechanism; |
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131 return true; |
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132 end |
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133 end |
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134 |
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135 -- feed new messages to process into the library |
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136 function method:process(message) |
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137 local err; |
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138 local data; |
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139 |
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140 if not self.first_step_done then |
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141 err, data = cyrussasl.server_start(self.cyrus, self.selected, message or "") |
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142 self.first_step_done = true; |
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143 else |
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144 err, data = cyrussasl.server_step(self.cyrus, message or "") |
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145 end |
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146 |
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147 self.username = cyrussasl.get_username(self.cyrus) |
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148 |
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149 if (err == 0) then -- SASL_OK |
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150 if self.require_provisioning and not self.require_provisioning(self.username) then |
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151 return "failure", "not-authorized", "User authenticated successfully, but not provisioned for XMPP"; |
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152 end |
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153 return "success", data |
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154 elseif (err == 1) then -- SASL_CONTINUE |
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155 return "challenge", data |
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156 elseif (err == -4) then -- SASL_NOMECH |
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157 log("debug", "SASL mechanism not available from remote end") |
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158 return "failure", "invalid-mechanism", "SASL mechanism not available" |
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159 elseif (err == -13) then -- SASL_BADAUTH |
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160 return "failure", "not-authorized", sasl_errstring[err]; |
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161 else |
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162 log("debug", "Got SASL error condition %d: %s", err, sasl_errstring[err]); |
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163 return "failure", "undefined-condition", sasl_errstring[err]; |
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164 end |
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165 end |
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166 |
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167 return { |
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168 new = new; |
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169 }; |
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