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def ccmp.xt_short

bend-osdev-cipher-modes@0.1.0.0 · PROOF.bend:1797

import bend-osdev-cipher-modes@0.1.0.0/PROOF.bend as PROOF
import Base
import bend-osdev-bytes@0.1.0.0/bytes.bend as B
import bend-osdev-cipher-modes@0.1.0.0/cipher_modes.bend as M
import bend-osdev-cipher-modes@0.1.0.0/ccm.bend as CC

1797# the CTR tail is as short as the plaintext tail
1798def ccmp.xt_short(~K: Data, ~enc: K -> M.CmBlock -> M.CmBlock, +k: K, +a0: M.CmBlock, +ys: List<&2, U32>) -> {Nat.is_lt(B.len(M.cm.xor_bytes(M.cm.split.tail(M.cm.split(B.mask(ys))), M.cm.bytes_of(enc(k, CC.ccm.ai(a0, U32.add(1, U32.from_nat(List.length(&2, M.CmBlock, M.cm.split.blocks(M.cm.split(B.mask(ys))))))))))), 16n) == True{} : Bool}:
1799  %Equal.sym(Nat, B.len(M.cm.xor_bytes(M.cm.split.tail(M.cm.split(B.mask(ys))), M.cm.bytes_of(enc(k, CC.ccm.ai(a0, U32.add(1, U32.from_nat(List.length(&2, M.CmBlock, M.cm.split.blocks(M.cm.split(B.mask(ys))))))))))), B.len(M.cm.split.tail(M.cm.split(B.mask(ys)))), li.len_xor(M.cm.split.tail(M.cm.split(B.mask(ys))), M.cm.bytes_of(enc(k, CC.ccm.ai(a0, U32.add(1, U32.from_nat(List.length(&2, M.CmBlock, M.cm.split.blocks(M.cm.split(B.mask(ys))))))))))(na.lt_le(B.len(M.cm.split.tail(M.cm.split(B.mask(ys)))), 16n)(sp.tail_short(ys)))) : {Nat.is_lt(_, 16n) == True{} : Bool}
1800  sp.tail_short(ys)

Uses (21)

Used by (1)