Public domain chacha20.go implements the ChaCha20 encryption and decryption algorithm by D. J. Bernstein. chacha20.go is derived from Bernstein's public domain ref implementation. chacha20.go implements crypto/cipher.Stream and io.Read interfaces. chacha20.go and chacha20_test.go are in the public domain and may be used for any purpose.
This version uses goroutines, yielding 8X the performance on a 3.504 GHz 12-processor Mac Studio with M2 Max.
ChaCha20 has been widely adopted.
Example use:
import "github.com/charltoncr/chacha20"
import "crypto/rand"
// ...
var m = []byte("This is a test.") // put a real message in m here
c := make([]byte, len(m))
key := make([]byte, 32) // 16 is acceptable; 32 is recommended
rand.Read(key) // use your real key here
iv := make([]byte, 8) // must be 8
rand.Read(iv) // use your real initialization vector here
ctx := chacha20.New(key, iv) // create a chacha20 context
ctx.Encrypt(m, c) // encrypt m into c
// ...
ctx = chacha20.New(key, iv) // must use same key/iv as encrypt to decrypt
ctx.Decrypt(c, m) // decrypt c back into m
// ...chacha20.go can also perform as ChaCha8 and ChaCha12 by using SetRounds(8) or SetRounds(12).