54 lines
1.1 KiB
Lua
54 lines
1.1 KiB
Lua
local _M = {}
|
|
|
|
local seeds = {}
|
|
local original_randomseed = math.randomseed
|
|
|
|
local function get_seed_from_urandom()
|
|
local seed
|
|
local frandom, err = io.open("/dev/urandom", "rb")
|
|
if not frandom then
|
|
ngx.log(ngx.WARN, 'failed to open /dev/urandom: ', err)
|
|
return nil
|
|
end
|
|
|
|
local str = frandom:read(4)
|
|
frandom:close()
|
|
if not str then
|
|
ngx.log(ngx.WARN, 'failed to read data from /dev/urandom')
|
|
return nil
|
|
end
|
|
|
|
seed = 0
|
|
for i = 1, 4 do
|
|
seed = 256 * seed + str:byte(i)
|
|
end
|
|
|
|
return seed
|
|
end
|
|
|
|
math.randomseed = function(seed)
|
|
local pid = ngx.worker.pid()
|
|
if seeds[pid] then
|
|
ngx.log(ngx.WARN,
|
|
string.format("ignoring math.randomseed(%d) since PRNG is already seeded for worker %d", seed, pid))
|
|
return
|
|
end
|
|
|
|
original_randomseed(seed)
|
|
seeds[pid] = seed
|
|
end
|
|
|
|
local function randomseed()
|
|
local seed = get_seed_from_urandom()
|
|
if not seed then
|
|
ngx.log(ngx.WARN, 'failed to get seed from urandom')
|
|
seed = ngx.now() * 1000 + ngx.worker.pid()
|
|
end
|
|
math.randomseed(seed)
|
|
end
|
|
|
|
function _M.init_worker()
|
|
randomseed()
|
|
end
|
|
|
|
return _M
|