-- 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.
-local md5 = require "util.hashes".md5;
-local log = require "util.logger".init("sasl");
-local st = require "util.stanza";
-local set = require "util.set";
-local array = require "util.array";
-local to_unicode = require "util.encodings".idna.to_unicode;
-
-local tostring = tostring;
local pairs, ipairs = pairs, ipairs;
-local t_insert, t_concat = table.insert, table.concat;
-local s_match = string.match;
+local t_insert = table.insert;
local type = type
-local error = error
local setmetatable = setmetatable;
local assert = assert;
local require = require;
-require "util.iterators"
-local keys = keys
-
-local array = require "util.array"
module "sasl"
--[[
state = false : disabled
state = true : enabled
state = nil : non-existant
+
+Channel Binding:
+
+To enable support of channel binding in some mechanisms you need to provide appropriate callbacks in a table
+at profile.cb.
+
+Example:
+ profile.cb["tls-unique"] = function(self)
+ return self.user
+ end
+
]]
local method = {};
method.__index = method;
local mechanisms = {};
local backend_mechanism = {};
+local mechanism_channelbindings = {};
-- register a new SASL mechanims
-local function registerMechanism(name, backends, f)
+function registerMechanism(name, backends, f, cb_backends)
assert(type(name) == "string", "Parameter name MUST be a string.");
assert(type(backends) == "string" or type(backends) == "table", "Parameter backends MUST be either a string or a table.");
assert(type(f) == "function", "Parameter f MUST be a function.");
+ if cb_backends then assert(type(cb_backends) == "table"); end
mechanisms[name] = f
+ if cb_backends then
+ mechanism_channelbindings[name] = {};
+ for _, cb_name in ipairs(cb_backends) do
+ mechanism_channelbindings[name][cb_name] = true;
+ end
+ end
for _, backend_name in ipairs(backends) do
if backend_mechanism[backend_name] == nil then backend_mechanism[backend_name] = {}; end
t_insert(backend_mechanism[backend_name], name);
end
-- create a new SASL object which can be used to authenticate clients
-function new(realm, profile, forbidden)
- local sasl_i = {profile = profile};
- sasl_i.realm = realm;
- local s = setmetatable(sasl_i, method);
- if forbidden == nil then forbidden = {} end
- s:forbidden(forbidden)
- return s;
+function new(realm, profile)
+ local mechanisms = profile.mechanisms;
+ if not mechanisms then
+ mechanisms = {};
+ for backend, f in pairs(profile) do
+ if backend_mechanism[backend] then
+ for _, mechanism in ipairs(backend_mechanism[backend]) do
+ mechanisms[mechanism] = true;
+ end
+ end
+ end
+ profile.mechanisms = mechanisms;
+ end
+ return setmetatable({ profile = profile, realm = realm, mechs = mechanisms }, method);
end
--- get a fresh clone with the same realm, profiles and forbidden mechanisms
-function method:clean_clone()
- return new(self.realm, self.profile, self:forbidden())
+-- add a channel binding handler
+function method:add_cb_handler(name, f)
+ if type(self.profile.cb) ~= "table" then
+ self.profile.cb = {};
+ end
+ self.profile.cb[name] = f;
+ return self;
end
--- set the forbidden mechanisms
-function method:forbidden( restrict )
- if restrict then
- -- set forbidden
- self.restrict = set.new(restrict);
- else
- -- get forbidden
- return array.collect(self.restrict:items());
- end
+-- get a fresh clone with the same realm and profile
+function method:clean_clone()
+ return new(self.realm, self.profile)
end
-- get a list of possible SASL mechanims to use
function method:mechanisms()
- local mechanisms = {}
- for backend, f in pairs(self.profile) do
- if backend_mechanism[backend] then
- for _, mechanism in ipairs(backend_mechanism[backend]) do
- if not self.restrict:contains(mechanism) then
- mechanisms[mechanism] = true;
+ local current_mechs = {};
+ for mech, _ in pairs(self.mechs) do
+ if mechanism_channelbindings[mech] then
+ if self.profile.cb then
+ local ok = false;
+ for cb_name, _ in pairs(self.profile.cb) do
+ if mechanism_channelbindings[mech][cb_name] then
+ ok = true;
+ end
end
+ if ok == true then current_mechs[mech] = true; end
end
+ else
+ current_mechs[mech] = true;
end
end
- self["possible_mechanisms"] = mechanisms;
- return array.collect(keys(mechanisms));
+ return current_mechs;
end
-- select a mechanism to use
function method:select(mechanism)
- if self.mech_i then
- return false;
+ if not self.selected and self.mechs[mechanism] then
+ self.selected = mechanism;
+ return true;
end
-
- self.mech_i = mechanisms[mechanism]
- if self.mech_i == nil then
- return false;
- end
- return true;
end
-- feed new messages to process into the library
function method:process(message)
--if message == "" or message == nil then return "failure", "malformed-request" end
- return self.mech_i(self, message);
+ return mechanisms[self.selected](self, message);
end
-- load the mechanisms
-local load_mechs = {"plain", "digest-md5", "anonymous", "scram"}
-for _, mech in ipairs(load_mechs) do
- local name = "util.sasl."..mech;
- local m = require(name);
- m.init(registerMechanism)
-end
+require "util.sasl.plain" .init(registerMechanism);
+require "util.sasl.digest-md5".init(registerMechanism);
+require "util.sasl.anonymous" .init(registerMechanism);
+require "util.sasl.scram" .init(registerMechanism);
+require "util.sasl.external" .init(registerMechanism);
return _M;