utils

Documentation

Index

• func ConstantTimeCmp(a, b []byte, l int) int
• func DecomposeNAF(out []int, s []byte, n, w int)

Functions

func ConstantTimeCmp

func ConstantTimeCmp(a, b []byte, l int) int

ConstantTimeCmp returns 1 if a > b, 0 if a == b, -1 otherwise a or b must not be nil and treated as unsigned big endian, should both in length l

func DecomposeNAF

func DecomposeNAF(out []int, s []byte, n, w int)

DecomposeNAF decomposes n-bit big endian integer s into w-NAF in LE See Algorithm 1 of https://www.iacr.org/archive/ches2014/87310103/87310103.pdf by Naomi Benger, Joop van de Pol, Nigel P. Smart, and Yuval Yarom This function should run very quickly therefore very hard to measure its timing or cache use. out must contain all zero or be newly created