/
multi2.go
123 lines (88 loc) · 2.43 KB
/
multi2.go
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package multi2
import (
"fmt"
"crypto/cipher"
"github.com/deatil/go-cryptobin/tool/alias"
)
const BlockSize = 8
type KeySizeError int
func (k KeySizeError) Error() string {
return fmt.Sprintf("cryptobin/multi2: invalid key size %d", int(k))
}
type multi2Cipher struct {
N int32
uk [8]uint32
}
// NewCipher creates and returns a new cipher.Block.
func NewCipher(key []byte, rounds int32) (cipher.Block, error) {
k := len(key)
switch k {
case 40:
break
default:
return nil, KeySizeError(len(key))
}
c := new(multi2Cipher)
c.expandKey(key, rounds)
return c, nil
}
func (this *multi2Cipher) BlockSize() int {
return BlockSize
}
func (this *multi2Cipher) Encrypt(dst, src []byte) {
if len(src) < BlockSize {
panic("cryptobin/multi2: input not full block")
}
if len(dst) < BlockSize {
panic("cryptobin/multi2: output not full block")
}
if alias.InexactOverlap(dst[:BlockSize], src[:BlockSize]) {
panic("cryptobin/multi2: invalid buffer overlap")
}
encSrc := bytesToUint32s(src)
encDst := make([]uint32, len(encSrc))
this.encrypt(encDst, encSrc)
resBytes := uint32sToBytes(encDst)
copy(dst, resBytes)
}
func (this *multi2Cipher) Decrypt(dst, src []byte) {
if len(src) < BlockSize {
panic("cryptobin/multi2: input not full block")
}
if len(dst) < BlockSize {
panic("cryptobin/multi2: output not full block")
}
if alias.InexactOverlap(dst[:BlockSize], src[:BlockSize]) {
panic("cryptobin/multi2: invalid buffer overlap")
}
encSrc := bytesToUint32s(src)
encDst := make([]uint32, len(encSrc))
this.decrypt(encDst, encSrc)
resBytes := uint32sToBytes(encDst)
copy(dst, resBytes)
}
func (this *multi2Cipher) expandKey(key []byte, num_rounds int32) {
var sk [8]uint32
var dk [2]uint32
in_key := bytesToUint32s(key)
this.N = num_rounds;
copy(sk[0:], in_key[:8])
copy(dk[0:], in_key[8:])
setup(dk[:], sk[:], this.uk[:])
}
func (this *multi2Cipher) encrypt(dst []uint32, src []uint32) {
var p [2]uint32
p[0] = src[0]
p[1] = src[1]
encrypt(p[:], this.N, this.uk[:])
dst[0] = p[0]
dst[1] = p[1]
}
func (this *multi2Cipher) decrypt(dst []uint32, src []uint32) {
var p [2]uint32
p[0] = src[0]
p[1] = src[1]
decrypt(p[:], this.N, this.uk[:])
dst[0] = p[0]
dst[1] = p[1]
}