law xtea_cbc_round_trip

bend-osdev-crypto@0.1.0.0 · LAWS.bend:1099

import Base
import bend-osdev-legacy-ciphers@0.1.0.0/legacy_ciphers.bend as L
import bend-osdev-legacy-ciphers@0.1.0.0/xtea.bend as Xt
import bend-osdev-crypto@0.1.0.0/modes.bend as Md
import bend-osdev-crypto@0.1.0.0/inst_lc.bend as LC

1099# XTEA, little-endian words (legacy-ciphers) in CBC (modes.bend): decryption undoes encryption, for every key, IV and list of blocks
1100law xtea_cbc_round_trip:
1101  for +k: Xt.LcXteaKey
1102  for +iv: L.LcBlock64
1103  for +bs: List<&2, L.LcBlock64>
1104  {Md.CrCbc.decrypt_blocks(~Xt.LcXteaKey, ~L.LcBlock64, ~Xt.LcXtea.decrypt, ~LC.CrBlk64.xor, k, iv, Md.CrCbc.encrypt_blocks(~Xt.LcXteaKey, ~L.LcBlock64, ~Xt.LcXtea.encrypt, ~LC.CrBlk64.xor, k, iv, bs)) == bs : List<&2, L.LcBlock64>}