constant-time-zero? ( seq -- ? )
Cryptographic utilities

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Vocabulary
crypto.utils

Inputs

seq	a sequence

Outputs

?	t if all zeros, f otherwise

Word description
Checks if all bytes in a sequence are zero in constant time. Always examines all bytes regardless of where non-zero bytes occur.

Examples

USING: byte-arrays crypto.utils ; B{ 0 0 0 0 } constant-time-zero?
! => t

USING: byte-arrays crypto.utils ; B{ 0 0 1 0 } constant-time-zero?
! => f

Definition

USING: kernel math sequences ;

IN: crypto.utils

: constant-time-zero? ( seq -- ? ) 0 [ bitor ] reduce 0 = ;