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def xtime_word

bend-collections@1.0.0.0 · src/crypto/aes/sbox.bend:146

import bend-collections@1.0.0.0/src/crypto/aes/sbox.bend as Sbox
import Base

146# {02} * x in GF(2^8) (FIPS 197 section 4.2.1, xtime): shift left and, when
147# bit 7 was set, add x^8 = {1b}; the reduction mask is 0 - bit7, not a branch.
148def xtime_word(+x: U32) -> U32:
149  U32.xor(U32.and(254, U32.shln(x, 1n)), U32.and(27, U32.sub(0, U32.and(1, U32.shrn(x, 7n)))))

Uses (6)

Used by (1)