diff options
Diffstat (limited to 'util/sasl.lua')
| -rw-r--r-- | util/sasl.lua | 117 |
1 files changed, 57 insertions, 60 deletions
diff --git a/util/sasl.lua b/util/sasl.lua index 295f5684..d176fd85 100644 --- a/util/sasl.lua +++ b/util/sasl.lua @@ -1,14 +1,14 @@ -- sasl.lua v0.4 -- Copyright (C) 2008-2009 Tobias Markmann --- +-- -- All rights reserved. --- +-- -- Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: --- +-- -- * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. -- * 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. -- * 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. --- +-- -- 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. @@ -20,7 +20,6 @@ local generate_uuid = require "util.uuid".generate; local t_insert, t_concat = table.insert, table.concat; local to_byte, to_char = string.byte, string.char; local to_unicode = require "util.encodings".idna.to_unicode; -local saslprep = require "util.encodings".stringprep.saslprep; local s_match = string.match; local gmatch = string.gmatch local string = string @@ -31,60 +30,56 @@ local print = print module "sasl" -local function new_plain(realm, password_handler) - local object = { mechanism = "PLAIN", realm = realm, password_handler = password_handler} +-- Credentials handler: +-- Arguments: ("PLAIN", user, host, password) +-- Returns: true (success) | false (fail) | nil (user unknown) +local function new_plain(realm, credentials_handler) + local object = { mechanism = "PLAIN", realm = realm, credentials_handler = credentials_handler} function object.feed(self, message) - if message == "" or message == nil then return "failure", "malformed-request" end local response = message local authorization = s_match(response, "([^%z]+)") local authentication = s_match(response, "%z([^%z]+)%z") local password = s_match(response, "%z[^%z]+%z([^%z]+)") - authorization, authentication, password = saslprep(authorization), saslprep(authentication), saslprep(password); - - if authentication == nil or password == nil then return "failure", "malformed-request" end - - local password_encoding, correct_password = self.password_handler(authentication, self.realm, self.realm, "PLAIN") - - if correct_password == nil then return "failure", "not-authorized" - elseif correct_password == false then return "failure", "account-disabled" end - - local claimed_password = "" - if password_encoding == nil then claimed_password = password - else claimed_password = password_encoding(password) end - claimed_password = saslprep(claimed_password); - - self.username = authentication - if claimed_password == correct_password then - return "success" - else - return "failure", "not-authorized" - end - end - return object -end + if authentication == nil or password == nil then return "failure", "malformed-request" end + self.username = authentication + local auth_success = self.credentials_handler("PLAIN", self.username, self.realm, password) + + if auth_success then + return "success" + elseif auth_success == nil then + return "failure", "account-disabled" + else + return "failure", "not-authorized" + end + end + return object +end +-- credentials_handler: +-- Arguments: (mechanism, node, domain, realm, decoder) +-- Returns: Password encoding, (plaintext) password -- implementing RFC 2831 -local function new_digest_md5(realm, password_handler) +local function new_digest_md5(realm, credentials_handler) --TODO complete support for authzid local function serialize(message) local data = "" - + if type(message) ~= "table" then error("serialize needs an argument of type table.") end - + -- testing all possible values + if message["realm"] then data = data..[[realm="]]..message.realm..[[",]] end if message["nonce"] then data = data..[[nonce="]]..message.nonce..[[",]] end if message["qop"] then data = data..[[qop="]]..message.qop..[[",]] end if message["charset"] then data = data..[[charset=]]..message.charset.."," end if message["algorithm"] then data = data..[[algorithm=]]..message.algorithm.."," end - if message["realm"] then data = data..[[realm="]]..message.realm..[[",]] end if message["rspauth"] then data = data..[[rspauth=]]..message.rspauth.."," end data = data:gsub(",$", "") return data end - + local function utf8tolatin1ifpossible(passwd) local i = 1; while i <= #passwd do @@ -140,16 +135,16 @@ local function new_digest_md5(realm, password_handler) return message; end - local object = { mechanism = "DIGEST-MD5", realm = realm, password_handler = password_handler}; - + local object = { mechanism = "DIGEST-MD5", realm = realm, credentials_handler = credentials_handler}; + object.nonce = generate_uuid(); object.step = 0; object.nonce_count = {}; - + function object.feed(self, message) self.step = self.step + 1; if (self.step == 1) then - local challenge = serialize({ nonce = object.nonce, + local challenge = serialize({ nonce = object.nonce, qop = "auth", charset = "utf-8", algorithm = "md5-sess", @@ -161,13 +156,13 @@ local function new_digest_md5(realm, password_handler) if response["nc"] then if self.nonce_count[response["nc"]] then return "failure", "not-authorized" end end - + -- check for username, it's REQUIRED by RFC 2831 if not response["username"] then return "failure", "malformed-request"; end self["username"] = response["username"]; - + -- check for nonce, ... if not response["nonce"] then return "failure", "malformed-request"; @@ -175,23 +170,23 @@ local function new_digest_md5(realm, password_handler) -- check if it's the right nonce if response["nonce"] ~= tostring(self.nonce) then return "failure", "malformed-request" end end - + if not response["cnonce"] then return "failure", "malformed-request", "Missing entry for cnonce in SASL message." end if not response["qop"] then response["qop"] = "auth" end - + if response["realm"] == nil or response["realm"] == "" then response["realm"] = ""; elseif response["realm"] ~= self.realm then return "failure", "not-authorized", "Incorrect realm value"; end - + local decoder; if response["charset"] == nil then decoder = utf8tolatin1ifpossible; elseif response["charset"] ~= "utf-8" then 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."; end - + local domain = ""; local protocol = ""; if response["digest-uri"] then @@ -200,10 +195,10 @@ local function new_digest_md5(realm, password_handler) else return "failure", "malformed-request", "Missing entry for digest-uri in SASL message." end - + --TODO maybe realm support self.username = response["username"]; - local password_encoding, Y = self.password_handler(response["username"], to_unicode(domain), response["realm"], "DIGEST-MD5", decoder); + local password_encoding, Y = self.credentials_handler("DIGEST-MD5", response["username"], self.realm, response["realm"], decoder); if Y == nil then return "failure", "not-authorized" elseif Y == false then return "failure", "account-disabled" end local A1 = ""; @@ -219,27 +214,27 @@ local function new_digest_md5(realm, password_handler) A1 = Y..":"..response["nonce"]..":"..response["cnonce"]; end local A2 = "AUTHENTICATE:"..protocol.."/"..domain; - + local HA1 = md5(A1, true); local HA2 = md5(A2, true); - + local KD = HA1..":"..response["nonce"]..":"..response["nc"]..":"..response["cnonce"]..":"..response["qop"]..":"..HA2; local response_value = md5(KD, true); - + if response_value == response["response"] then -- calculate rspauth A2 = ":"..protocol.."/"..domain; - + HA1 = md5(A1, true); HA2 = md5(A2, true); - + KD = HA1..":"..response["nonce"]..":"..response["nc"]..":"..response["cnonce"]..":"..response["qop"]..":"..HA2 local rspauth = md5(KD, true); self.authenticated = true; return "challenge", serialize({rspauth = rspauth}); else return "failure", "not-authorized", "The response provided by the client doesn't match the one we calculated." - end + end elseif self.step == 3 then if self.authenticated ~= nil then return "success" else return "failure", "malformed-request" end @@ -248,8 +243,10 @@ local function new_digest_md5(realm, password_handler) return object; end -local function new_anonymous(realm, password_handler) - local object = { mechanism = "ANONYMOUS", realm = realm, password_handler = password_handler} +-- Credentials handler: Can be nil. If specified, should take the mechanism as +-- the only argument, and return true for OK, or false for not-OK (TODO) +local function new_anonymous(realm, credentials_handler) + local object = { mechanism = "ANONYMOUS", realm = realm, credentials_handler = credentials_handler} function object.feed(self, message) return "success" end @@ -258,11 +255,11 @@ local function new_anonymous(realm, password_handler) end -function new(mechanism, realm, password_handler) +function new(mechanism, realm, credentials_handler) local object - if mechanism == "PLAIN" then object = new_plain(realm, password_handler) - elseif mechanism == "DIGEST-MD5" then object = new_digest_md5(realm, password_handler) - elseif mechanism == "ANONYMOUS" then object = new_anonymous(realm, password_handler) + if mechanism == "PLAIN" then object = new_plain(realm, credentials_handler) + elseif mechanism == "DIGEST-MD5" then object = new_digest_md5(realm, credentials_handler) + elseif mechanism == "ANONYMOUS" then object = new_anonymous(realm, credentials_handler) else log("debug", "Unsupported SASL mechanism: "..tostring(mechanism)); return nil |