#!/usr/bin/python3

import sys
import binascii

from eddsalib import Ed25519

def munge_string(s, pos, change):
    return (s[:pos] +
            int.to_bytes(s[pos] ^ change, 1, "little") +
            s[pos+1:])

# Read a file in the format of
# http://ed25519.cr.yp.to/python/sign.input
lineno = 0
while True:
   line = sys.stdin.readline()
   if not line:
       break
   lineno = lineno + 1
   print(lineno)
   fields = line.split(":")
   secret = (binascii.unhexlify(fields[0]))[:32]
   public = binascii.unhexlify(fields[1])
   msg = binascii.unhexlify(fields[2])
   # Colon or not at the end?
   if len(fields)>4:
       sig = fields[3]
   else:
       sig = fields[3][:-1]
   signature = binascii.unhexlify(sig)[:64]

   privkey,pubkey = Ed25519.keygen(secret)
   assert public == pubkey
   assert signature == Ed25519.sign(privkey, pubkey, msg)
   assert Ed25519.verify(public, msg, signature)
   if len(msg) == 0:
       bad_msg = b"x"
   else:
       bad_msg = munge_string(msg, len(msg) // 3, 4)
   assert not Ed25519.verify(public, bad_msg, signature)
   bad_signature = munge_string(signature, 20, 8)
   assert not Ed25519.verify(public, msg, bad_signature)
   bad_signature = munge_string(signature, 40, 16)
   assert not Ed25519.verify(public, msg, bad_signature)