-- sasl.lua v0.4
-- Copyright (C) 2008-2010 Tobias Markmann
--
--- All rights reserved.
+-- All rights reserved.
--
--- Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
+-- 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.
+-- * 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.
+-- 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 s_match = string.match;
local type = type
-local string = string
local base64 = require "util.encodings".base64;
-local hmac_sha1 = require "util.hmac".sha1;
+local hmac_sha1 = require "util.hashes".hmac_sha1;
local sha1 = require "util.hashes".sha1;
+local Hi = require "util.hashes".scram_Hi_sha1;
local generate_uuid = require "util.uuid".generate;
local saslprep = require "util.encodings".stringprep.saslprep;
+local nodeprep = require "util.encodings".stringprep.nodeprep;
local log = require "util.logger".init("sasl");
local t_concat = table.concat;
local char = string.char;
local byte = string.byte;
-module "scram"
+module "sasl.scram"
--=========================
---SASL SCRAM-SHA-1 according to draft-ietf-sasl-scram-10
+--SASL SCRAM-SHA-1 according to RFC 5802
--[[
Supported Authentication Backends
-scram-{MECH}:
+scram_{MECH}:
+ -- MECH being a standard hash name (like those at IANA's hash registry) with '-' replaced with '_'
function(username, realm)
- return salted_password, iteration_count, salt, state;
+ return stored_key, server_key, iteration_count, salt, state;
end
+
+Supported Channel Binding Backends
+
+'tls-unique' according to RFC 5929
]]
local default_i = 4096
-local function bp( b )
- local result = ""
- for i=1, b:len() do
- result = result.."\\"..b:byte(i)
- end
- return result
-end
-
local xor_map = {0;1;2;3;4;5;6;7;8;9;10;11;12;13;14;15;1;0;3;2;5;4;7;6;9;8;11;10;13;12;15;14;2;3;0;1;6;7;4;5;10;11;8;9;14;15;12;13;3;2;1;0;7;6;5;4;11;10;9;8;15;14;13;12;4;5;6;7;0;1;2;3;12;13;14;15;8;9;10;11;5;4;7;6;1;0;3;2;13;12;15;14;9;8;11;10;6;7;4;5;2;3;0;1;14;15;12;13;10;11;8;9;7;6;5;4;3;2;1;0;15;14;13;12;11;10;9;8;8;9;10;11;12;13;14;15;0;1;2;3;4;5;6;7;9;8;11;10;13;12;15;14;1;0;3;2;5;4;7;6;10;11;8;9;14;15;12;13;2;3;0;1;6;7;4;5;11;10;9;8;15;14;13;12;3;2;1;0;7;6;5;4;12;13;14;15;8;9;10;11;4;5;6;7;0;1;2;3;13;12;15;14;9;8;11;10;5;4;7;6;1;0;3;2;14;15;12;13;10;11;8;9;6;7;4;5;2;3;0;1;15;14;13;12;11;10;9;8;7;6;5;4;3;2;1;0;};
local result = {};
return t_concat(result);
end
--- hash algorithm independent Hi(PBKDF2) implementation
-local function Hi(hmac, str, salt, i)
- local Ust = hmac(str, salt.."\0\0\0\1");
- local res = Ust;
- for n=1,i-1 do
- local Und = hmac(str, Ust)
- res = binaryXOR(res, Und)
- Ust = Und
- end
- return res
-end
-
-local function validate_username(username)
+local function validate_username(username, _nodeprep)
-- check for forbidden char sequences
for eq in username:gmatch("=(.?.?)") do
- if eq ~= "2D" and eq ~= "3D" then
- return false
- end
+ if eq ~= "2C" and eq ~= "3D" then
+ return false
+ end
end
-
- -- replace =2D with , and =3D with =
- username = username:gsub("=2D", ",");
+
+ -- replace =2C with , and =3D with =
+ username = username:gsub("=2C", ",");
username = username:gsub("=3D", "=");
-
+
-- apply SASLprep
username = saslprep(username);
- return username;
+
+ if username and _nodeprep ~= false then
+ username = (_nodeprep or nodeprep)(username);
+ end
+
+ return username and #username>0 and username;
+end
+
+local function hashprep(hashname)
+ return hashname:lower():gsub("-", "_");
+end
+
+function getAuthenticationDatabaseSHA1(password, salt, iteration_count)
+ if type(password) ~= "string" or type(salt) ~= "string" or type(iteration_count) ~= "number" then
+ return false, "inappropriate argument types"
+ end
+ if iteration_count < 4096 then
+ log("warn", "Iteration count < 4096 which is the suggested minimum according to RFC 5802.")
+ end
+ local salted_password = Hi(password, salt, iteration_count);
+ local stored_key = sha1(hmac_sha1(salted_password, "Client Key"))
+ local server_key = hmac_sha1(salted_password, "Server Key");
+ return true, stored_key, server_key
end
local function scram_gen(hash_name, H_f, HMAC_f)
local function scram_hash(self, message)
if not self.state then self["state"] = {} end
-
+ local support_channel_binding = false;
+ if self.profile.cb then support_channel_binding = true; end
+
+ if type(message) ~= "string" or #message == 0 then return "failure", "malformed-request" end
if not self.state.name then
-- we are processing client_first_message
local client_first_message = message;
+
+ -- TODO: fail if authzid is provided, since we don't support them yet
self.state["client_first_message"] = client_first_message;
- self.state["name"] = client_first_message:match("n=(.+),r=")
- self.state["clientnonce"] = client_first_message:match("r=([^,]+)")
-
- if not self.state.name or not self.state.clientnonce then
+ self.state["gs2_cbind_flag"], self.state["gs2_cbind_name"], self.state["authzid"], self.state["name"], self.state["clientnonce"]
+ = client_first_message:match("^([ynp])=?([%a%-]*),(.*),n=(.*),r=([^,]*).*");
+
+ local gs2_cbind_flag = self.state.gs2_cbind_flag;
+
+ if not gs2_cbind_flag then
return "failure", "malformed-request";
end
-
- self.state.name = validate_username(self.state.name);
+
+ if support_channel_binding and gs2_cbind_flag == "y" then
+ -- "y" -> client does support channel binding
+ -- but thinks the server does not.
+ return "failure", "malformed-request";
+ end
+
+ if gs2_cbind_flag == "n" then
+ -- "n" -> client doesn't support channel binding.
+ support_channel_binding = false;
+ end
+
+ if support_channel_binding and gs2_cbind_flag == "p" then
+ -- check whether we support the proposed channel binding type
+ if not self.profile.cb[self.state.gs2_cbind_name] then
+ return "failure", "malformed-request", "Proposed channel binding type isn't supported.";
+ end
+ else
+ -- no channel binding,
+ self.state.gs2_cbind_name = nil;
+ end
+
+ if not self.state.name or not self.state.clientnonce then
+ return "failure", "malformed-request", "Channel binding isn't support at this time.";
+ end
+
+ self.state.name = validate_username(self.state.name, self.profile.nodeprep);
if not self.state.name then
log("debug", "Username violates either SASLprep or contains forbidden character sequences.")
return "failure", "malformed-request", "Invalid username.";
end
-
+
self.state["servernonce"] = generate_uuid();
-
+
-- retreive credentials
if self.profile.plain then
- local password, state = self.profile.plain(self.state.name, self.realm)
+ local password, state = self.profile.plain(self, self.state.name, self.realm)
if state == nil then return "failure", "not-authorized"
elseif state == false then return "failure", "account-disabled" end
-
+
password = saslprep(password);
if not password then
log("debug", "Password violates SASLprep.");
return "failure", "not-authorized", "Invalid password."
end
+
self.state.salt = generate_uuid();
self.state.iteration_count = default_i;
- self.state.salted_password = Hi(HMAC_f, password, self.state.salt, default_i);
- elseif self.profile["scram_"..hash_name] then
- local salted_password, iteration_count, salt, state = self.profile["scram-"..hash_name](self.state.name, self.realm);
+
+ local succ = false;
+ succ, self.state.stored_key, self.state.server_key = getAuthenticationDatabaseSHA1(password, self.state.salt, default_i, self.state.iteration_count);
+ if not succ then
+ log("error", "Generating authentication database failed. Reason: %s", self.state.stored_key);
+ return "failure", "temporary-auth-failure";
+ end
+ elseif self.profile["scram_"..hashprep(hash_name)] then
+ local stored_key, server_key, iteration_count, salt, state = self.profile["scram_"..hashprep(hash_name)](self, self.state.name, self.realm);
if state == nil then return "failure", "not-authorized"
elseif state == false then return "failure", "account-disabled" end
-
- self.state.salted_password = salted_password;
+
+ self.state.stored_key = stored_key;
+ self.state.server_key = server_key;
self.state.iteration_count = iteration_count;
self.state.salt = salt
end
-
+
local server_first_message = "r="..self.state.clientnonce..self.state.servernonce..",s="..base64.encode(self.state.salt)..",i="..self.state.iteration_count;
self.state["server_first_message"] = server_first_message;
return "challenge", server_first_message
else
- if type(message) ~= "string" then return "failure", "malformed-request" end
-- we are processing client_final_message
local client_final_message = message;
-
- self.state["proof"] = client_final_message:match("p=(.+)");
- self.state["nonce"] = client_final_message:match("r=(.+),p=");
- self.state["channelbinding"] = client_final_message:match("c=(.+),r=");
+
+ self.state["channelbinding"], self.state["nonce"], self.state["proof"] = client_final_message:match("^c=(.*),r=(.*),.*p=(.*)");
+
if not self.state.proof or not self.state.nonce or not self.state.channelbinding then
return "failure", "malformed-request", "Missing an attribute(p, r or c) in SASL message.";
end
-
- local SaltedPassword = self.state.salted_password;
- local ClientKey = HMAC_f(SaltedPassword, "Client Key")
- local ServerKey = HMAC_f(SaltedPassword, "Server Key")
- local StoredKey = H_f(ClientKey)
+
+ if self.state.gs2_cbind_name then
+ -- we support channelbinding, so check if the value is valid
+ local client_gs2_header = base64.decode(self.state.channelbinding)
+ local our_client_gs2_header = "p="..self.state.gs2_cbind_name..","..self.state["authzid"]..","..self.profile.cb[self.state.gs2_cbind_name](self);
+
+ if client_gs2_header ~= our_client_gs2_header then
+ return "failure", "malformed-request", "Invalid channel binding value.";
+ end
+ end
+
+ if self.state.nonce ~= self.state.clientnonce..self.state.servernonce then
+ return "failure", "malformed-request", "Wrong nonce in client-final-message.";
+ end
+
+ local ServerKey = self.state.server_key;
+ local StoredKey = self.state.stored_key;
+
local AuthMessage = "n=" .. s_match(self.state.client_first_message,"n=(.+)") .. "," .. self.state.server_first_message .. "," .. s_match(client_final_message, "(.+),p=.+")
local ClientSignature = HMAC_f(StoredKey, AuthMessage)
- local ClientProof = binaryXOR(ClientKey, ClientSignature)
+ local ClientKey = binaryXOR(ClientSignature, base64.decode(self.state.proof))
local ServerSignature = HMAC_f(ServerKey, AuthMessage)
-
- if base64.encode(ClientProof) == self.state.proof then
+
+ if StoredKey == H_f(ClientKey) then
local server_final_message = "v="..base64.encode(ServerSignature);
self["username"] = self.state.name;
return "success", server_final_message;
function init(registerMechanism)
local function registerSCRAMMechanism(hash_name, hash, hmac_hash)
- registerMechanism("SCRAM-"..hash_name, {"plain", "scram_"..(hash_name:lower())}, scram_gen(hash_name:lower(), hash, hmac_hash));
+ registerMechanism("SCRAM-"..hash_name, {"plain", "scram_"..(hashprep(hash_name))}, scram_gen(hash_name:lower(), hash, hmac_hash));
+
+ -- register channel binding equivalent
+ registerMechanism("SCRAM-"..hash_name.."-PLUS", {"plain", "scram_"..(hashprep(hash_name))}, scram_gen(hash_name:lower(), hash, hmac_hash), {"tls-unique"});
end
-
+
registerSCRAMMechanism("SHA-1", sha1, hmac_sha1);
end
-return _M;
\ No newline at end of file
+return _M;
projects / prosody.git / blobdiff