Stream.front_correct: law of bend-collections-laws-crypto@1.0.0.0
Import: import bend-collections-laws-crypto@1.0.0.0/proofs/crypto/chacha/stream.bend as Stream
Lines 211-218 of bend-collections-laws-crypto@1.0.0.0/proofs/crypto/chacha/stream.bend: https://jend.leeeet.dev/read.txt?path=bend-collections-laws-crypto@1.0.0.0/proofs/crypto/chacha/stream.bend&start_line=211&end_line=218

import Base
import bend-collections-laws-crypto@1.0.0.0/src/crypto/chacha/chacha20.bend as I
import bend-collections-laws-crypto@1.0.0.0/spec/crypto/chacha.bend as R

# One block of the stream: the XORed front is the spec's.
law front_correct:
  for +r: Nat
  for +kb: List<&2, U32>
  for +c: U32
  for +nb: List<&2, U32>
  for +xs: List<&2, U32>
  {I.xor_front(I.keystream(r, I.key(kb), c, I.nonce(nb)), xs) == R.xor_bytes(R.prefix(64n, xs), R.block_rounds(r, kb, c, nb)) : List<&2, U32>}

Uses (18):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Equal.cong
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Equal.trans
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List.length
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-crypto@1.0.0.0/proofs/crypto/chacha/stream.bend&name=bytes_length
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-crypto@1.0.0.0/proofs/crypto/chacha/stream.bend&name=keystream_correct
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-crypto@1.0.0.0/proofs/crypto/chacha/stream.bend&name=xor_front_eq
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-crypto@1.0.0.0/spec/crypto/chacha.bend&name=block_rounds
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-crypto@1.0.0.0/spec/crypto/chacha.bend&name=prefix
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-crypto@1.0.0.0/spec/crypto/chacha.bend&name=xor_bytes
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-crypto@1.0.0.0/src/crypto/chacha/chacha20.bend&name=key
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-crypto@1.0.0.0/src/crypto/chacha/chacha20.bend&name=keystream
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-crypto@1.0.0.0/src/crypto/chacha/chacha20.bend&name=nonce
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-crypto@1.0.0.0/src/crypto/chacha/chacha20.bend&name=state
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-crypto@1.0.0.0/src/crypto/chacha/chacha20.bend&name=xor_front
  https://jend.leeeet.dev/definition.txt?path=bend-collections-laws-crypto@1.0.0.0/src/crypto/chacha/core.bend&name=block