| var createHash = require('create-hash') | |
| var Buffer = require('safe-buffer').Buffer | |
| module.exports = function (seed, len) { | |
| var t = Buffer.alloc(0) | |
| var i = 0 | |
| var c | |
| while (t.length < len) { | |
| c = i2ops(i++) | |
| t = Buffer.concat([t, createHash('sha1').update(seed).update(c).digest()]) | |
| } | |
| return t.slice(0, len) | |
| } | |
| function i2ops (c) { | |
| var out = Buffer.allocUnsafe(4) | |
| out.writeUInt32BE(c, 0) | |
| return out | |
| } |