def cbcp.go

bend-osdev-cipher-modes@0.1.0.0 · PROOF.bend:1280

import Base
import bend-osdev-cipher-modes@0.1.0.0/cipher_modes.bend as M
import bend-osdev-cipher-modes@0.1.0.0/cbc.bend as C

1280def cbcp.go(~K: Data, ~enc: K -> M.CmBlock -> M.CmBlock, ~dec: K -> M.CmBlock -> M.CmBlock, ~inv: @k: K -> @b: M.CmBlock -> {dec(k, enc(k, b)) == b : M.CmBlock}, +k: K, bs: List<&2, M.CmBlock>, +iv: M.CmBlock) -> {C.cbc.dec(~K, ~dec, k, C.cbc.enc(~K, ~enc, k, bs, iv), iv) == bs : List<&2, M.CmBlock>}:
1281  match bs:
1282    case Nil{}:
1283      {==}
1284    case Con{+p, +t}:
1285      %Equal.sym(M.CmBlock, dec(k, enc(k, M.CmBlock.xor(iv, p))), M.CmBlock.xor(iv, p), inv(k, M.CmBlock.xor(iv, p))) : {Con{M.CmBlock.xor(iv, _), C.cbc.dec(~K, ~dec, k, C.cbc.enc(~K, ~enc, k, t, enc(k, M.CmBlock.xor(iv, p))), enc(k, M.CmBlock.xor(iv, p)))} == Con{p, t} : List<&2, M.CmBlock>}
1286      %bx.block(iv, p) : {Con{M.CmBlock.xor(iv, M.CmBlock.xor(iv, p)), C.cbc.dec(~K, ~dec, k, C.cbc.enc(~K, ~enc, k, t, enc(k, M.CmBlock.xor(iv, p))), enc(k, M.CmBlock.xor(iv, p)))} == Con{_, t} : List<&2, M.CmBlock>}
1287      %cbcp.go(~K, ~enc, ~dec, ~inv, k, t, enc(k, M.CmBlock.xor(iv, p))) : {Con{M.CmBlock.xor(iv, M.CmBlock.xor(iv, p)), C.cbc.dec(~K, ~dec, k, C.cbc.enc(~K, ~enc, k, t, enc(k, M.CmBlock.xor(iv, p))), enc(k, M.CmBlock.xor(iv, p)))} == Con{M.CmBlock.xor(iv, M.CmBlock.xor(iv, p)), _} : List<&2, M.CmBlock>}
1288      {==}