Gcm.mulx: def of bend-collections@1.0.0.0
Import: import bend-collections@1.0.0.0/src/crypto/aes/gcm.bend as Gcm
Lines 25-32 of bend-collections@1.0.0.0/src/crypto/aes/gcm.bend: https://jend.leeeet.dev/read.txt?path=bend-collections@1.0.0.0/src/crypto/aes/gcm.bend&start_line=25&end_line=32

import Base

# V * x: the block shifted one bit toward x^127, x^128 = R.
def mulx(v: Block) -> Block:
  match v:
    case B{+a, +b, +c, +d}:
      B{U32.xor(U32.and(3774873600, U32.sub(0, U32.and(1, d))), U32.shrn(a, 1n)),
        U32.or(U32.shln(a, 31n), U32.shrn(b, 1n)),
        U32.or(U32.shln(b, 31n), U32.shrn(c, 1n)),
        U32.or(U32.shln(c, 31n), U32.shrn(d, 1n))}

Uses (7):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.and
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.or
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.shln
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.shrn
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.sub
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.xor
  https://jend.leeeet.dev/definition.txt?path=bend-collections@1.0.0.0/src/crypto/aes/gcm.bend&name=Block