module "scram"
--=========================
---SASL SCRAM-SHA-1 according to draft-ietf-sasl-scram-10
+--SASL SCRAM-SHA-1 according to RFC 5802
--[[
Supported Authentication Backends
end
-- hash algorithm independent Hi(PBKDF2) implementation
-local function Hi(hmac, str, salt, i)
+function Hi(hmac, str, salt, i)
local Ust = hmac(str, salt.."\0\0\0\1");
- local res = Ust;
+ local res = Ust;
for n=1,i-1 do
local Und = hmac(str, Ust)
res = binaryXOR(res, Und)
-- check for forbidden char sequences
for eq in username:gmatch("=(.?.?)") do
if eq ~= "2D" and eq ~= "3D" then
- return false
- end
+ return false
+ end
end
-- replace =2D with , and =3D with =
-- 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;