[tankf33der]

Helps a lot.

import crypto.rc4
import rand
import time

fn main() {
	key := rand.bytes(32)!
	mut c := rc4.new_cipher(key)!
	mut out := []u8{len: 10_000_000}
	mut txt := []u8{len: 10_000_000, init: 255}

	t1 := time.now()
	c.xor_key_stream(mut out, txt)
	println(time.since(t1))
}

master:

$ v run rc4.v && v -prod rc4.v && ./rc4
656.013ms
116.518ms

patch:

$ v run rc4.v && v -prod rc4.v && ./rc4
54.620ms
19.244ms

Note: I want to add that I have my own test vector against another RC4 implementation with very wide coverage.
Everything is ok.

[spytheman]

Excellent work.
Thank you @tankf33der 🙇🏻 .