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all: use math/bits.RotateLeft

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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
Download Patch File Download Diff File Expand all files Collapse all files
twofish/twofish.go
+14 -21
View File
@@ -18,7 +18,10 @@ package twofish // import "golang.org/x/crypto/twofish"
// LibTomCrypt is free for all purposes under the public domain.
// It was heavily inspired by the go blowfish package.
import "strconv"
import (
"math/bits"
"strconv"
)
// BlockSize is the constant block size of Twofish.
const BlockSize = 16
@@ -76,12 +79,12 @@ func NewCipher(key []byte) (*Cipher, error) {
tmp[j] = 2*i + 1
}
B := h(tmp[:], key, 1)
B = rol(B, 8)
B = bits.RotateLeft32(B, 8)
c.k[2*i] = A + B
// K[2i+1] = (A + 2B) <<< 9
c.k[2*i+1] = rol(2*B+A, 9)
c.k[2*i+1] = bits.RotateLeft32(2*B+A, 9)
}
// Calculate sboxes
@@ -129,16 +132,6 @@ func load32l(src []byte) uint32 {
return uint32(src[0]) | uint32(src[1])<<8 | uint32(src[2])<<16 | uint32(src[3])<<24
}
// rol returns x after a left circular rotation of y bits.
func rol(x, y uint32) uint32 {
return (x << (y & 31)) | (x >> (32 - (y & 31)))
}
// ror returns x after a right circular rotation of y bits.
func ror(x, y uint32) uint32 {
return (x >> (y & 31)) | (x << (32 - (y & 31)))
}
// The RS matrix. See [TWOFISH] 4.3
var rs = [4][8]byte{
{0x01, 0xA4, 0x55, 0x87, 0x5A, 0x58, 0xDB, 0x9E},
@@ -282,13 +275,13 @@ func (c *Cipher) Encrypt(dst, src []byte) {
k := c.k[8+i*4 : 12+i*4]
t2 := S2[byte(ib)] ^ S3[byte(ib>>8)] ^ S4[byte(ib>>16)] ^ S1[byte(ib>>24)]
t1 := S1[byte(ia)] ^ S2[byte(ia>>8)] ^ S3[byte(ia>>16)] ^ S4[byte(ia>>24)] + t2
ic = ror(ic^(t1+k[0]), 1)
id = rol(id, 1) ^ (t2 + t1 + k[1])
ic = bits.RotateLeft32(ic^(t1+k[0]), -1)
id = bits.RotateLeft32(id, 1) ^ (t2 + t1 + k[1])
t2 = S2[byte(id)] ^ S3[byte(id>>8)] ^ S4[byte(id>>16)] ^ S1[byte(id>>24)]
t1 = S1[byte(ic)] ^ S2[byte(ic>>8)] ^ S3[byte(ic>>16)] ^ S4[byte(ic>>24)] + t2
ia = ror(ia^(t1+k[2]), 1)
ib = rol(ib, 1) ^ (t2 + t1 + k[3])
ia = bits.RotateLeft32(ia^(t1+k[2]), -1)
ib = bits.RotateLeft32(ib, 1) ^ (t2 + t1 + k[3])
}
// Output with "undo last swap"
@@ -326,13 +319,13 @@ func (c *Cipher) Decrypt(dst, src []byte) {
k := c.k[4+i*4 : 8+i*4]
t2 := S2[byte(id)] ^ S3[byte(id>>8)] ^ S4[byte(id>>16)] ^ S1[byte(id>>24)]
t1 := S1[byte(ic)] ^ S2[byte(ic>>8)] ^ S3[byte(ic>>16)] ^ S4[byte(ic>>24)] + t2
ia = rol(ia, 1) ^ (t1 + k[2])
ib = ror(ib^(t2+t1+k[3]), 1)
ia = bits.RotateLeft32(ia, 1) ^ (t1 + k[2])
ib = bits.RotateLeft32(ib^(t2+t1+k[3]), -1)
t2 = S2[byte(ib)] ^ S3[byte(ib>>8)] ^ S4[byte(ib>>16)] ^ S1[byte(ib>>24)]
t1 = S1[byte(ia)] ^ S2[byte(ia>>8)] ^ S3[byte(ia>>16)] ^ S4[byte(ia>>24)] + t2
ic = rol(ic, 1) ^ (t1 + k[0])
id = ror(id^(t2+t1+k[1]), 1)
ic = bits.RotateLeft32(ic, 1) ^ (t1 + k[0])
id = bits.RotateLeft32(id^(t2+t1+k[1]), -1)
}
// Undo pre-whitening