-- Prosody IM

-- Copyright (C) 2008-2010 Matthew Wild

-- Copyright (C) 2008-2010 Waqas Hussain

-- Copyright (C) 2010 Jeff Mitchell

--

-- This project is MIT/X11 licensed. Please see the

-- COPYING file in the source package for more information.

--

local datamanager = require "util.datamanager";

local log = require "util.logger".init("usermanager");

local type = type;

local error = error;

local ipairs = ipairs;

local hashes = require "util.hashes";

local jid_bare = require "util.jid".bare;

local getAuthenticationDatabaseSHA1 = require "util.sasl.scram".getAuthenticationDatabaseSHA1;

local config = require "core.configmanager";

local usermanager = require "core.usermanager";

local generate_uuid = require "util.uuid".generate;

local new_sasl = require "util.sasl".new;

local nodeprep = require "util.encodings".stringprep.nodeprep;

local hosts = hosts;

-- TODO: remove these two lines in near future

local hmac_sha1 = require "util.hmac".sha1;

local sha1 = require "util.hashes".sha1;

local prosody = _G.prosody;

-- Default; can be set per-user

local iteration_count = 4096;

function new_hashpass_provider(host)

	local provider = { name = "internal_hashed" };

	log("debug", "initializing hashpass authentication provider for host '%s'", host);

	function provider.test_password(username, password)

		local credentials = datamanager.load(username, host, "accounts") or {};

		if credentials.password ~= nil and string.len(credentials.password) ~= 0 then

			if credentials.password ~= password then

				return nil, "Auth failed. Provided password is incorrect.";

			end

			if provider.set_password(username, credentials.password) == nil then

				return nil, "Auth failed. Could not set hashed password from plaintext.";

			else

				return true;

			end

		end

		if credentials.iteration_count == nil or credentials.salt == nil or string.len(credentials.salt) == 0 then

			return nil, "Auth failed. Stored salt and iteration count information is not complete.";

		end

		-- convert hexpass to stored_key and server_key

		-- TODO: remove this in near future

		if credentials.hashpass then

			local salted_password = credentials.hashpass:gsub("..", function(x) return string.char(tonumber(x, 16)); end);

			credentials.stored_key = sha1(hmac_sha1(salted_password, "Client Key")):gsub(".", function (c) return ("%02x"):format(c:byte()); end);

			credentials.server_key = hmac_sha1(salted_password, "Server Key"):gsub(".", function (c) return ("%02x"):format(c:byte()); end);

			credentials.hashpass = nil

			datamanager.store(username, host, "accounts", credentials);

		end

		local valid, stored_key, server_key = getAuthenticationDatabaseSHA1(password, credentials.salt, credentials.iteration_count);

		local stored_key_hex = stored_key:gsub(".", function (c) return ("%02x"):format(c:byte()); end);

		local server_key_hex = server_key:gsub(".", function (c) return ("%02x"):format(c:byte()); end);

		if valid and stored_key_hex == credentials.stored_key and server_key_hex == credentials.server_key then

			return true;

		else

			return nil, "Auth failed. Invalid username, password, or password hash information.";

		end

	end

	function provider.set_password(username, password)

		local account = datamanager.load(username, host, "accounts");

		if account then

			account.salt = account.salt or generate_uuid();

			account.iteration_count = account.iteration_count or iteration_count;

			local valid, stored_key, server_key = getAuthenticationDatabaseSHA1(password, account.salt, account.iteration_count);

			local stored_key_hex = stored_key:gsub(".", function (c) return ("%02x"):format(c:byte()); end);

			local server_key_hex = server_key:gsub(".", function (c) return ("%02x"):format(c:byte()); end);

			account.stored_key = stored_key_hex

			account.server_key = server_key_hex

			account.password = nil;

			return datamanager.store(username, host, "accounts", account);

		end

		return nil, "Account not available.";

	end

	function provider.user_exists(username)

		local account = datamanager.load(username, host, "accounts");

		if not account then

			log("debug", "account not found for username '%s' at host '%s'", username, module.host);

			return nil, "Auth failed. Invalid username";

		end

			log("debug", "account password not set or zero-length for username '%s' at host '%s'", username, module.host);

			return nil, "Auth failed. Password invalid.";

		return true;

	end

	function provider.create_user(username, password)

		local salt = generate_uuid();

		local valid, stored_key, server_key = getAuthenticationDatabaseSHA1(password, salt, iteration_count);

		local stored_key_hex = stored_key:gsub(".", function (c) return ("%02x"):format(c:byte()); end);

		local server_key_hex = server_key:gsub(".", function (c) return ("%02x"):format(c:byte()); end);

		return datamanager.store(username, host, "accounts", {stored_key = stored_key_hex, server_key = server_key_hex, salt = salt, iteration_count = iteration_count});

	end

	function provider.get_sasl_handler()

		local realm = module:get_option("sasl_realm") or module.host;

		local testpass_authentication_profile = {

			plain_test = function(username, password, realm)

				local prepped_username = nodeprep(username);

				if not prepped_username then

					log("debug", "NODEprep failed on username: %s", username);

					return "", nil;

				end

				return usermanager.test_password(prepped_username, password, realm), true;

			end,

			scram_sha_1 = function(username, realm)

				local credentials = datamanager.load(username, host, "accounts") or {};

				if credentials.password then

					usermanager.set_password(username, credentials.password, host);

					credentials = datamanager.load(username, host, "accounts") or {};

				end

				-- convert hexpass to stored_key and server_key

				-- TODO: remove this in near future

				if credentials.hashpass then

					local salted_password = credentials.hashpass:gsub("..", function(x) return string.char(tonumber(x, 16)); end);

					credentials.stored_key = sha1(hmac_sha1(salted_password, "Client Key")):gsub(".", function (c) return ("%02x"):format(c:byte()); end);

					credentials.server_key = hmac_sha1(salted_password, "Server Key"):gsub(".", function (c) return ("%02x"):format(c:byte()); end);

					credentials.hashpass = nil

					datamanager.store(username, host, "accounts", credentials);

				end

				local stored_key, server_key, iteration_count, salt = credentials.stored_key, credentials.server_key, credentials.iteration_count, credentials.salt;

				stored_key = stored_key and stored_key:gsub("..", function(x) return string.char(tonumber(x, 16)); end);

				server_key = server_key and server_key:gsub("..", function(x) return string.char(tonumber(x, 16)); end);

				return stored_key, server_key, iteration_count, salt, true;

			end

		};

		return new_sasl(realm, testpass_authentication_profile);

	end

	function provider.is_admin(jid)

		local admins = module:get_option_array("admins");

		if admins ~= config.get("*", "core", "admins") and type(admins) == "table" then

			jid = jid_bare(jid);

			for _,admin in ipairs(admins) do

				if admin == jid then return true; end

			end

		end

	end

	return provider;

end

module:add_item("auth-provider", new_hashpass_provider(module.host));