智能照明系统APP-本地串口
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
LightingSystemApp-serial/.svn/pristine/e6/e6961ce6a9d99e4b4b4a17d6cdf...

20 lines
423 B

3 years ago
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
}