phase1.zokrates

import "LIBSNARK/sha256packed"

def hash(field[16] deck) -> (field[2]):
    field res = 0
    for field i in 0..16 do
        res = res + deck[i] * (2**(4*i))
    endfor
    h0, h1 = sha256packed(0, 0, 0, res)
    return [h0, h1]

def isInDeck(field i, field[16] deck) -> (field):
    field res = 1
    for field card in 0..16 do
        res = res * (deck[card] - i)
    endfor
    return res

def isPermutation(field[16] deck) -> (field):
    for field card in 0..16 do
        0 == isInDeck(card, deck)
    endfor
    return 1

def main(private field[16] deck, field salt) -> (field[2]):
    1 == isPermutation(deck)
    return hash(deck, salt)

phase2.zokrates

import "LIBSNARK/sha256packed"

def hash(field[16] deck) -> (field[2]):
    field res = 0
    for field i in 0..16 do
        res = res + deck[i] * (2**(4*i))
    endfor
    h0, h1 = sha256packed(0, 0, 0, res)
    return [h0, h1]

def main(private field[16] deck, field nullifier) -> (field[2]):
    return hash(deck), nullifier