golang加密系列之aes/cbc/pkcs7padding

func Encrypt(plantText, key []byte) ([]byte, error) {
   block, err := aes.NewCipher(key) //选择加密算法
   if err != nil {
      return nil, err
   }
   plantText = PKCS7Padding(plantText, block.BlockSize())
   blockModel := cipher.NewCBCEncrypter(block, key)
   ciphertext := make([]byte, len(plantText))
   blockModel.CryptBlocks(ciphertext, plantText)
   return ciphertext, nil
}
func PKCS7Padding(ciphertext []byte, blockSize int) []byte {
   padding := blockSize - len(ciphertext)%blockSize
   padtext := bytes.Repeat([]byte{byte(padding)}, padding)
   return append(ciphertext, padtext...)
}

func Decrypt(ciphertext, key []byte) ([]byte, error) {
   keyBytes := []byte(key)
   block, err := aes.NewCipher(keyBytes) //选择加密算法
   if err != nil {
      return nil, err
   }
   blockModel := cipher.NewCBCDecrypter(block, keyBytes)
   plantText := make([]byte, len(ciphertext))
   blockModel.CryptBlocks(plantText, ciphertext)
   plantText = PKCS7UnPadding(plantText, block.BlockSize())
   return plantText, nil
}
func PKCS7UnPadding(plantText []byte, blockSize int) []byte {
   length := len(plantText)
   unpadding := int(plantText[length-1])
   return plantText[:(length - unpadding)]
}