law xtea_pcbc_round_trip

bend-osdev-crypto@0.1.0.0 · LAWS.bend:1106

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/pcbc.bend as Pc
import bend-osdev-crypto@0.1.0.0/inst_lc.bend as LC

1106# XTEA, little-endian words (legacy-ciphers) in PCBC (pcbc.bend): decryption undoes encryption, for every key, IV and list of blocks
1107law xtea_pcbc_round_trip:
1108  for +k: Xt.LcXteaKey
1109  for +iv: L.LcBlock64
1110  for +bs: List<&2, L.LcBlock64>
1111  {Pc.CrPcbc.decrypt_blocks(~Xt.LcXteaKey, ~L.LcBlock64, ~Xt.LcXtea.decrypt, ~LC.CrBlk64.xor, k, iv, Pc.CrPcbc.encrypt_blocks(~Xt.LcXteaKey, ~L.LcBlock64, ~Xt.LcXtea.encrypt, ~LC.CrBlk64.xor, k, iv, bs)) == bs : List<&2, L.LcBlock64>}