32 lines
662 B
JavaScript
32 lines
662 B
JavaScript
|
var xor = require('buffer-xor')
|
||
|
|
|
||
|
|
function incr32 (iv) {
|
||
|
|
var len = iv.length
|
||
|
|
var item
|
||
|
|
while (len--) {
|
||
|
|
item = iv.readUInt8(len)
|
||
|
|
if (item === 255) {
|
||
|
|
iv.writeUInt8(0, len)
|
||
|
|
} else {
|
||
|
|
item++
|
||
|
|
iv.writeUInt8(item, len)
|
||
|
|
break
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
function getBlock (self) {
|
||
|
|
var out = self._cipher.encryptBlock(self._prev)
|
||
|
|
incr32(self._prev)
|
||
|
|
return out
|
||
|
|
}
|
||
|
|
|
||
|
|
exports.encrypt = function (self, chunk) {
|
||
|
|
while (self._cache.length < chunk.length) {
|
||
|
|
self._cache = Buffer.concat([self._cache, getBlock(self)])
|
||
|
|
}
|
||
|
|
var pad = self._cache.slice(0, chunk.length)
|
||
|
|
self._cache = self._cache.slice(chunk.length)
|
||
|
|
return xor(chunk, pad)
|
||
|
|
}
|