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 cyrussasl = require "cyrussasl";

    15 local log = require "util.logger".init("sasl_cyrus");

    16 local array = require "util.array";

    17 

    18 local tostring = tostring;

    19 local pairs, ipairs = pairs, ipairs;

    20 local t_insert, t_concat = table.insert, table.concat;

    21 local s_match = string.match;

    22 

    23 local keys = keys;

    24 

    25 local print = print

    26 

    27 module "sasl_cyrus"

    28 

    29 local method = {};

    30 method.__index = method;

    31 local mechanisms = {};

    32 local backend_mechanism = {};

    33 

    34 -- register a new SASL mechanims

    35 local function registerMechanism(name, backends, f)

    36 	assert(type(name) == "string", "Parameter name MUST be a string.");

    37 	assert(type(backends) == "string" or type(backends) == "table", "Parameter backends MUST be either a string or a table.");

    38 	assert(type(f) == "function", "Parameter f MUST be a function.");

    39 	mechanisms[name] = f

    40 	for _, backend_name in ipairs(backends) do

    41 		if backend_mechanism[backend_name] == nil then backend_mechanism[backend_name] = {}; end

    42 		t_insert(backend_mechanism[backend_name], name);

    43 	end

    44 end

    45 

    46 -- create a new SASL object which can be used to authenticate clients

    47 function new(realm, service_name)

    48 	local sasl_i = {};

    49 	sasl_i.realm = realm;

    50 	sasl_i.service_name = service_name;

    51 	sasl_i.cyrus = cyrussasl.server_new(service_name, realm, realm, nil, nil)

    52 	if sasl_i.cyrus ~= 0, 

    53 		   "got NULL return value from server_new")

    54 	cyrussasl.setssf(sasl_i.cyrus, 0, 0xffffffff)

    55 	local s = setmetatable(sasl_i, method);

    56 	return s;

    57 end

    58 

    59 -- get a fresh clone with the same realm, profiles and forbidden mechanisms

    60 function method:clean_clone()

    61 	return new(self.realm, self.service_name)

    62 end

    63 

    64 -- set the forbidden mechanisms

    65 function method:forbidden( restrict )

    66 	log("debug", "Called method:forbidden. NOT IMPLEMENTED.")

    67 	return {}

    68 end

    69 

    70 -- get a list of possible SASL mechanims to use

    71 function method:mechanisms()

    72 	local mechanisms = {}

    73 	local cyrus_mechs = cyrussasl.listmech(self.cyrus)

    74 	for w in s_gmatch(cyrus_mechs, "%a+") do

    75 		mechanisms[w] = true;

    76 	end

    77 	self.mechanisms = mechanisms

    78 	return array.collect(keys(mechanisms));

    79 end

    80 

    81 -- select a mechanism to use

    82 function method:select(mechanism)

    83 	self.mechanism = mechanism;

    84 	return not self.mechanisms[mechanisms];

    85 end

    86 

    87 -- feed new messages to process into the library

    88 function method:process(message)

    89 	local err;

    90 	local data;

    91 	if self.mechanism then

    92 		err, data = cyrussasl.server_start(self.cyrus, self.mechanism, message)

    93 	else

    94 		err, data = cyrussasl.server_step(self.cyrus, message)

    95 	end

    96 

    97 	self.username = cyrussasl.get_username(self.cyrus)

    98 

    99 	if (err == 0) then -- SASL_OK

   100 	   return "success", data

   101 	elseif (err == 1) then -- SASL_CONTINUE

   102 	   return "challenge", data

   103 	elseif (err == -4) then -- SASL_NOMECH

   104 	   log("debug", "SASL mechanism not available from remote end")

   105 	   return "failure", 

   106 	     "undefined-condition",

   107 	     "SASL mechanism not available"

   108 	elseif (err == -13) then -- SASL_BADAUTH

   109 	   return "failure", "not-authorized"

   110 	else

   111 	   log("debug", "Got SASL error condition %d", err)

   112 	   return "failure", 

   113 	     "undefined-condition",

   114 	     cyrussasl.get_message( self.cyrus )

   115 	end

   116 end

   117 

   118 return _M;