all: use math/bits.RotateLeft

Updates golang/go#31456

Change-Id: Idf043a25632526baa190bf42ed360cb79f85e493
GitHub-Last-Rev: 59461578926a85a87cc68dac96c0b7559766b7cf
GitHub-Pull-Request: golang/crypto#195
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/356518
Auto-Submit: Filippo Valsorda <filippo@golang.org>
Run-TryBot: Filippo Valsorda <filippo@golang.org>
Reviewed-by: Heschi Kreinick <heschi@google.com>
Reviewed-by: David Chase <drchase@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Filippo Valsorda <filippo@golang.org>
This commit is contained in:
Alexander Yastrebov
2022-10-24 17:35:37 +00:00
committed by Gopher Robot
parent 642fcc37f5
commit a3485e1740
8 changed files with 254 additions and 251 deletions
+25 -28
View File
@@ -14,6 +14,7 @@ package rc2
import (
"crypto/cipher"
"encoding/binary"
"math/bits"
)
// The rc2 block size in bytes
@@ -80,10 +81,6 @@ func expandKey(key []byte, t1 int) [64]uint16 {
return k
}
func rotl16(x uint16, b uint) uint16 {
return (x >> (16 - b)) | (x << b)
}
func (c *rc2Cipher) Encrypt(dst, src []byte) {
r0 := binary.LittleEndian.Uint16(src[0:])
@@ -96,22 +93,22 @@ func (c *rc2Cipher) Encrypt(dst, src []byte) {
for j <= 16 {
// mix r0
r0 = r0 + c.k[j] + (r3 & r2) + ((^r3) & r1)
r0 = rotl16(r0, 1)
r0 = bits.RotateLeft16(r0, 1)
j++
// mix r1
r1 = r1 + c.k[j] + (r0 & r3) + ((^r0) & r2)
r1 = rotl16(r1, 2)
r1 = bits.RotateLeft16(r1, 2)
j++
// mix r2
r2 = r2 + c.k[j] + (r1 & r0) + ((^r1) & r3)
r2 = rotl16(r2, 3)
r2 = bits.RotateLeft16(r2, 3)
j++
// mix r3
r3 = r3 + c.k[j] + (r2 & r1) + ((^r2) & r0)
r3 = rotl16(r3, 5)
r3 = bits.RotateLeft16(r3, 5)
j++
}
@@ -124,22 +121,22 @@ func (c *rc2Cipher) Encrypt(dst, src []byte) {
for j <= 40 {
// mix r0
r0 = r0 + c.k[j] + (r3 & r2) + ((^r3) & r1)
r0 = rotl16(r0, 1)
r0 = bits.RotateLeft16(r0, 1)
j++
// mix r1
r1 = r1 + c.k[j] + (r0 & r3) + ((^r0) & r2)
r1 = rotl16(r1, 2)
r1 = bits.RotateLeft16(r1, 2)
j++
// mix r2
r2 = r2 + c.k[j] + (r1 & r0) + ((^r1) & r3)
r2 = rotl16(r2, 3)
r2 = bits.RotateLeft16(r2, 3)
j++
// mix r3
r3 = r3 + c.k[j] + (r2 & r1) + ((^r2) & r0)
r3 = rotl16(r3, 5)
r3 = bits.RotateLeft16(r3, 5)
j++
}
@@ -152,22 +149,22 @@ func (c *rc2Cipher) Encrypt(dst, src []byte) {
for j <= 60 {
// mix r0
r0 = r0 + c.k[j] + (r3 & r2) + ((^r3) & r1)
r0 = rotl16(r0, 1)
r0 = bits.RotateLeft16(r0, 1)
j++
// mix r1
r1 = r1 + c.k[j] + (r0 & r3) + ((^r0) & r2)
r1 = rotl16(r1, 2)
r1 = bits.RotateLeft16(r1, 2)
j++
// mix r2
r2 = r2 + c.k[j] + (r1 & r0) + ((^r1) & r3)
r2 = rotl16(r2, 3)
r2 = bits.RotateLeft16(r2, 3)
j++
// mix r3
r3 = r3 + c.k[j] + (r2 & r1) + ((^r2) & r0)
r3 = rotl16(r3, 5)
r3 = bits.RotateLeft16(r3, 5)
j++
}
@@ -188,22 +185,22 @@ func (c *rc2Cipher) Decrypt(dst, src []byte) {
for j >= 44 {
// unmix r3
r3 = rotl16(r3, 16-5)
r3 = bits.RotateLeft16(r3, 16-5)
r3 = r3 - c.k[j] - (r2 & r1) - ((^r2) & r0)
j--
// unmix r2
r2 = rotl16(r2, 16-3)
r2 = bits.RotateLeft16(r2, 16-3)
r2 = r2 - c.k[j] - (r1 & r0) - ((^r1) & r3)
j--
// unmix r1
r1 = rotl16(r1, 16-2)
r1 = bits.RotateLeft16(r1, 16-2)
r1 = r1 - c.k[j] - (r0 & r3) - ((^r0) & r2)
j--
// unmix r0
r0 = rotl16(r0, 16-1)
r0 = bits.RotateLeft16(r0, 16-1)
r0 = r0 - c.k[j] - (r3 & r2) - ((^r3) & r1)
j--
}
@@ -215,22 +212,22 @@ func (c *rc2Cipher) Decrypt(dst, src []byte) {
for j >= 20 {
// unmix r3
r3 = rotl16(r3, 16-5)
r3 = bits.RotateLeft16(r3, 16-5)
r3 = r3 - c.k[j] - (r2 & r1) - ((^r2) & r0)
j--
// unmix r2
r2 = rotl16(r2, 16-3)
r2 = bits.RotateLeft16(r2, 16-3)
r2 = r2 - c.k[j] - (r1 & r0) - ((^r1) & r3)
j--
// unmix r1
r1 = rotl16(r1, 16-2)
r1 = bits.RotateLeft16(r1, 16-2)
r1 = r1 - c.k[j] - (r0 & r3) - ((^r0) & r2)
j--
// unmix r0
r0 = rotl16(r0, 16-1)
r0 = bits.RotateLeft16(r0, 16-1)
r0 = r0 - c.k[j] - (r3 & r2) - ((^r3) & r1)
j--
@@ -243,22 +240,22 @@ func (c *rc2Cipher) Decrypt(dst, src []byte) {
for j >= 0 {
// unmix r3
r3 = rotl16(r3, 16-5)
r3 = bits.RotateLeft16(r3, 16-5)
r3 = r3 - c.k[j] - (r2 & r1) - ((^r2) & r0)
j--
// unmix r2
r2 = rotl16(r2, 16-3)
r2 = bits.RotateLeft16(r2, 16-3)
r2 = r2 - c.k[j] - (r1 & r0) - ((^r1) & r3)
j--
// unmix r1
r1 = rotl16(r1, 16-2)
r1 = bits.RotateLeft16(r1, 16-2)
r1 = r1 - c.k[j] - (r0 & r3) - ((^r0) & r2)
j--
// unmix r0
r0 = rotl16(r0, 16-1)
r0 = bits.RotateLeft16(r0, 16-1)
r0 = r0 - c.k[j] - (r3 & r2) - ((^r3) & r1)
j--