From 244d10ac25d1adc0f10e089f8d457269b109897d Mon Sep 17 00:00:00 2001 From: siddharth Date: Sun, 10 Oct 2021 11:18:25 -0400 Subject: lib: move sha arithmetic functions to hash.go --- lib/hash.go | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'lib/hash.go') diff --git a/lib/hash.go b/lib/hash.go index f0f4625..363d3d6 100644 --- a/lib/hash.go +++ b/lib/hash.go @@ -28,6 +28,25 @@ func shaMessageBlocks(pm []byte) [][]uint32 { return mbs } +// (a + b + ...) mod 2^32 +func shaAdd(n ...uint32) uint32 { + sum := uint64(0) + for _, v := range n { + sum += uint64(v) + } + return uint32(sum & 0xFFFFFFFF) +} + +// Circular Right Shift +func shaRotr(x uint32, n uint) uint32 { + return (x >> n) | (x << (32 - n)) +} + +// Circular Left Shift +func shaRotl(x uint32, n uint) uint32 { + return (x << n) | (x >> (32 - n)) +} + // Returns Merkle–Damgård padding in bytes for length of mesage `l` // bytes. func MDPadding(l int) []byte { -- cgit v1.2.3