-- COPYING file in the source package for more information.
--
-local tostring = tostring;
-local os_time = os.time;
-local os_clock = os.clock;
-local ceil = math.ceil;
-local H = require "util.hashes".sha512;
+local ok, crand = pcall(require, "util.crand");
+if ok then return crand; end
-local last_uniq_time = 0;
-local function uniq_time()
- local new_uniq_time = os_time();
- if last_uniq_time >= new_uniq_time then new_uniq_time = last_uniq_time + 1; end
- last_uniq_time = new_uniq_time;
- return new_uniq_time;
-end
+local urandom, urandom_err = io.open("/dev/urandom", "r");
-local function new_random(x)
- return H(x..os_clock()..tostring({}));
+local function seed()
end
-local buffer = new_random(uniq_time());
-
-local function seed(x)
- buffer = new_random(buffer..x);
+local function bytes(n)
+ return urandom:read(n);
end
-local function bytes(n)
- if #buffer < n+4 then seed(uniq_time()); end
- local r = buffer:sub(1, n);
- buffer = buffer:sub(n+1);
- return r;
+if not urandom then
+ function bytes()
+ error("Unable to obtain a secure random number generator, please see https://prosody.im/doc/random ("..urandom_err..")");
+ end
end
return {