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-rw-r--r--util/uuid.lua43
1 files changed, 16 insertions, 27 deletions
diff --git a/util/uuid.lua b/util/uuid.lua
index bb70d000..58f792fd 100644
--- a/util/uuid.lua
+++ b/util/uuid.lua
@@ -6,44 +6,33 @@
-- COPYING file in the source package for more information.
--
-
-local tostring = tostring;
-local os_time = os.time;
-local os_clock = os.clock;
-local sha1 = require "util.hashes".sha1;
+local error = error;
+local round_up = math.ceil;
+local urandom, urandom_err = io.open("/dev/urandom", "r+");
module "uuid"
-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 function new_random(x)
- return sha1(x..os_clock()..tostring({}), true);
-end
-
-local buffer = new_random(uniq_time());
-local function _seed(x)
- buffer = new_random(buffer..x);
-end
local function get_nibbles(n)
- if #buffer < n then _seed(uniq_time()); end
- local r = buffer:sub(0, n);
- buffer = buffer:sub(n+1);
- return r;
+ local binary_random = urandom:read(round_up(n/2));
+ local hex_random = binary_random:gsub(".",
+ function (x) return ("%02x"):format(x:byte()) end);
+ return hex_random:sub(1, n);
end
local function get_twobits()
- return ("%x"):format(get_nibbles(1):byte() % 4 + 8);
+ return ("%x"):format(urandom:read(1):byte() % 4 + 8);
end
function generate()
+ if not urandom then
+ error("Unable to obtain a secure random number generator, please see https://prosody.im/doc/random ("..urandom_err..")");
+ end
-- generate RFC 4122 complaint UUIDs (version 4 - random)
return get_nibbles(8).."-"..get_nibbles(4).."-4"..get_nibbles(3).."-"..(get_twobits())..get_nibbles(3).."-"..get_nibbles(12);
end
-seed = _seed;
+
+function seed(x)
+ urandom:write(x);
+ urandom:flush();
+end
return _M;