From 244d10ac25d1adc0f10e089f8d457269b109897d Mon Sep 17 00:00:00 2001
From: siddharth <s@ricketyspace.net>
Date: Sun, 10 Oct 2021 11:18:25 -0400
Subject: lib: move sha arithmetic functions to hash.go
---
lib/hash.go | 19 +++++++++++++++++++
lib/sha1.go | 35 ++++++++---------------------------
2 files changed, 27 insertions(+), 27 deletions(-)
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 {
diff --git a/lib/sha1.go b/lib/sha1.go
index 5010bfb..e4ab369 100644
--- a/lib/sha1.go
+++ b/lib/sha1.go
@@ -21,25 +21,6 @@ var sha1IHashValues []uint32 = []uint32{
0xc3d2e1f0,
}
-// (a + b + ...) mod 2^32
-func sha1Add(n ...uint32) uint32 {
- sum := uint64(0)
- for _, v := range n {
- sum += uint64(v)
- }
- return uint32(sum & 0xFFFFFFFF)
-}
-
-// Circular Right Shift
-func sha1Rotr(x uint32, n uint) uint32 {
- return (x >> n) | (x << (32 - n))
-}
-
-// Circular Left Shift
-func sha1Rotl(x uint32, n uint) uint32 {
- return (x << n) | (x >> (32 - n))
-}
-
// SHA-1 - Function f_t(x, y, z)
func sha1FT(t int, x, y, z uint32) uint32 {
switch {
@@ -83,7 +64,7 @@ func sha1MessageSchedule(mb []uint32) []uint32 {
if t <= 15 {
w = append(w, mb[t])
} else {
- w = append(w, sha1Rotl(w[t-3]^w[t-8]^w[t-14]^w[t-16], 1))
+ w = append(w, shaRotl(w[t-3]^w[t-8]^w[t-14]^w[t-16], 1))
}
}
return w
@@ -142,21 +123,21 @@ func (s *Sha1) Hash() []byte {
e := h[4]
for t := 0; t <= 79; t++ {
- tmp := sha1Add(sha1Rotl(a, 5), sha1FT(t, b, c, d),
+ tmp := shaAdd(shaRotl(a, 5), sha1FT(t, b, c, d),
e, sha1KT(t), w[t])
e = d
d = c
- c = sha1Rotl(b, 30)
+ c = shaRotl(b, 30)
b = a
a = tmp
}
// Compute intermediate hash values.
- h[0] = sha1Add(a, h[0])
- h[1] = sha1Add(b, h[1])
- h[2] = sha1Add(c, h[2])
- h[3] = sha1Add(d, h[3])
- h[4] = sha1Add(e, h[4])
+ h[0] = shaAdd(a, h[0])
+ h[1] = shaAdd(b, h[1])
+ h[2] = shaAdd(c, h[2])
+ h[3] = shaAdd(d, h[3])
+ h[4] = shaAdd(e, h[4])
}
// Slurp sha1 digest from hash values.
--
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