ChaCha8 instead of ChaCha20

[smrt28]

Sorry for disturbing again :-)

It seems you use ChaCha8 instead of ChaCha20. This loop performs 2 rounds 4 times = 8 instead of 20.

  for (i = 8;i > 0;i -= 2) {
    QUARTERROUND( 0, 4, 8,12)
    QUARTERROUND( 1, 5, 9,13)
    QUARTERROUND( 2, 6,10,14)
    QUARTERROUND( 3, 7,11,15)
    QUARTERROUND( 0, 5,10,15)
    QUARTERROUND( 1, 6,11,12)
    QUARTERROUND( 2, 7, 8,13)
    QUARTERROUND( 3, 4, 9,14)
  }

It seems you took the reference code frome there:
https://cr.yp.to/streamciphers/timings/estreambench/submissions/salsa20/chacha8/ref/chacha.c

Notice, chacha8 in the URL path.

[skeeto]

Yup, you're right, thank you. I wrote a partial Go re-implementation of Enchive in 2019-ish and noticed this, but forgot to update the readme. I made that change just now. Fortunately it should have no material impact because 20 rounds is extremely conservative, which is why I wasn't worried about it upon discovery. ChaCha8 is plenty and probably more appropriate in this application anyway: Too Much Crypto https://eprint.iacr.org/2019/1492.pdf I really had originally intended ChaCha20, but I didn't understand it well enough at the time and messed this up.