diff options
Diffstat (limited to 'util/uuid.lua')
| -rw-r--r-- | util/uuid.lua | 43 |
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; |