1	# Laws about CAST-128 (cast5.bend): for every key (every key size) and
2	# block, decryption undoes encryption and encryption undoes decryption; and
3	# RFC 2144 B.1's 128-bit vector and a refused key, proved by computation.
4	import Base
5	import bend-osdev-bytes@0.1.1.0/bytes.bend as B
6	import bend-osdev-cipher-core@0.1.0.0/cipher_core.bend as L
7	import ./cast5.bend as C5
8	
9	# CAST-128 (RFC 2144), every key size
10	
11	law cast5_round_trip:
12	  for k: C5.LcCast5Key
13	  for +b: L.LcBlock64
14	  {C5.LcCast5.decrypt(k, C5.LcCast5.encrypt(k, b)) == b : L.LcBlock64}
15	
16	law cast5_round_trip_dual:
17	  for k: C5.LcCast5Key
18	  for +b: L.LcBlock64
19	  {C5.LcCast5.encrypt(k, C5.LcCast5.decrypt(k, b)) == b : L.LcBlock64}
20	
21	# Vectors: the specification's test values and refusals, proved by
22	# computation (gen/vectors.py)
23	
24	# BEGIN GENERATED by gen/vectors.py: vectors
25	# RFC 2144, Appendix B.1: CAST-128 with the 128-bit key
26	# 0123456712345678234567893456789A, plaintext 0123456789ABCDEF, ciphertext
27	# 238B4FE5847E44B2
28	law cast5_rfc2144:
29	  {Result.map(&2, &2, L.LcError, C5.LcCast5Key, L.LcBlock64, k => C5.LcCast5.encrypt(k, L.LcBlock64{19088743, 2309737967}), C5.LcCast5.key(B.Octets.of_list([1, 35, 69, 103, 18, 52, 86, 120, 35, 69, 103, 137, 52, 86, 120, 154]))) == Done{L.LcBlock64{596332517, 2222867634}} : Result<&2, &2, L.LcError, L.LcBlock64>}
30	
31	# a CAST-128 key of 4 bytes is refused (40 bits at least)
32	law cast5_bad_key_length:
33	  {Result.map(&2, &2, L.LcError, C5.LcCast5Key, Unit, k => Unit{}, C5.LcCast5.key(B.Octets.of_list([0, 0, 0, 0]))) == Fail{L.LcBadKeyLength{4n}} : Result<&2, &2, L.LcError, Unit>}
34	
35	# END GENERATED: vectors