/
sddes.go
86 lines (77 loc) · 2.32 KB
/
sddes.go
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package sddes
import (
"bytes"
"crypto/cipher"
"crypto/des"
)
func Encrypt(origData, key []byte, iv []byte) ([]byte, error) {
block, err := des.NewCipher(key)
if err != nil {
return nil, err
}
origData = PKCS5Padding(origData, block.BlockSize())
// origData = ZeroPadding(origData, block.BlockSize())
blockMode := cipher.NewCBCEncrypter(block, iv)
crypted := make([]byte, len(origData))
// 根据CryptBlocks方法的说明,如下方式初始化crypted也可以
// crypted := origData
blockMode.CryptBlocks(crypted, origData)
return crypted, nil
}
func Decrypt(crypted, key []byte, iv []byte) ([]byte, error) {
block, err := des.NewCipher(key)
if err != nil {
return nil, err
}
blockMode := cipher.NewCBCDecrypter(block, iv)
origData := make([]byte, len(crypted))
// origData := crypted
blockMode.CryptBlocks(origData, crypted)
origData = PKCS5UnPadding(origData)
// origData = ZeroUnPadding(origData)
return origData, nil
}
// 3DES加密
func TripleEncrypt(origData, key []byte, iv []byte) ([]byte, error) {
block, err := des.NewTripleDESCipher(key)
if err != nil {
return nil, err
}
origData = PKCS5Padding(origData, block.BlockSize())
blockMode := cipher.NewCBCEncrypter(block, iv)
crypted := make([]byte, len(origData))
blockMode.CryptBlocks(crypted, origData)
return crypted, nil
}
// 3DES解密
func TripleDecrypt(crypted, key []byte, iv []byte) ([]byte, error) {
block, err := des.NewTripleDESCipher(key)
if err != nil {
return nil, err
}
blockMode := cipher.NewCBCDecrypter(block, iv)
origData := make([]byte, len(crypted))
blockMode.CryptBlocks(origData, crypted)
origData = PKCS5UnPadding(origData)
return origData, nil
}
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.TrimRightFunc(origData, func(r rune) bool {
return r == rune(0)
})
}
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)]
}