Files
2019-08-08 17:13:34 +08:00

82 lines
1.8 KiB
Go

package des
import (
utils "anytunnel/at-common"
"bytes"
"crypto/des"
"encoding/hex"
"errors"
)
func PKCS5Padding(ciphertext []byte, blockSize int) []byte {
padding := blockSize - len(ciphertext)%blockSize
padtext := bytes.Repeat([]byte{byte(padding)}, padding)
return append(ciphertext, padtext...)
}
func PKCS5UnPadding(origData []byte) []byte {
length := len(origData)
unpadding := int(origData[length-1])
return origData[:(length - unpadding)]
}
func ZeroPadding(ciphertext []byte, blockSize int) []byte {
padding := blockSize - len(ciphertext)%blockSize
padtext := bytes.Repeat([]byte{0}, padding)
return append(ciphertext, padtext...)
}
func ZeroUnPadding(origData []byte) []byte {
return bytes.TrimFunc(origData,
func(r rune) bool {
return r == rune(0)
})
}
func Encrypt(src []byte, key string) (string, error) {
block, err := des.NewCipher([]byte(utils.Md5(key)[0:8]))
if err != nil {
return "", err
}
bs := block.BlockSize()
src = ZeroPadding(src, bs)
// src = PKCS5Padding(src, bs)
if len(src)%bs != 0 {
return "", errors.New("Need a multiple of the blocksize")
}
out := make([]byte, len(src))
dst := out
for len(src) > 0 {
block.Encrypt(dst, src[:bs])
src = src[bs:]
dst = dst[bs:]
}
return hex.EncodeToString(out), nil
}
func Decrypt(_src string, _key string) ([]byte, error) {
key := []byte(utils.Md5(_key)[0:8])
src, err := hex.DecodeString(_src)
if err != nil {
return nil, err
}
block, err := des.NewCipher(key)
if err != nil {
return nil, err
}
out := make([]byte, len(src))
dst := out
bs := block.BlockSize()
if len(src)%bs != 0 {
return nil, errors.New("crypto/cipher: input not full blocks")
}
for len(src) > 0 {
block.Decrypt(dst, src[:bs])
src = src[bs:]
dst = dst[bs:]
}
out = ZeroUnPadding(out)
// out = PKCS5UnPadding(out)
return out, nil
}