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}:
-- 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
]]
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 )
- local hash = hashname:lower()
- hash = hash:gsub("-", "_")
- return hash
+local function hashprep(hashname)
+ return hashname:lower():gsub("-", "_");
end
-function saltedPasswordSHA1(password, salt, iteration_count)
- local salted_password
+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
-
- return true, Hi(hmac_sha1, password, salt, iteration_count);
+ 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)
return "failure", "malformed-request", "Channel binding isn't support at this time.";
end
- self.state.name = validate_username(self.state.name);
+ 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.";
-- 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
self.state.iteration_count = default_i;
local succ = false;
- succ, self.state.salted_password = saltedPasswordSHA1(password, self.state.salt, default_i, self.state.iteration_count);
+ 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 salted password failed. Reason: %s", self.state.salted_password);
+ 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 salted_password, iteration_count, salt, state = self.profile["scram_"..hashprep(hash_name)](self.state.name, self.realm);
+ 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
return "failure", "malformed-request", "Wrong nonce in client-final-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)
+ 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;
projects / prosody.git / blobdiff