107 lines
2.6 KiB
Go
107 lines
2.6 KiB
Go
package security
|
||
|
||
import (
|
||
"bytes"
|
||
"crypto/aes"
|
||
"crypto/cipher"
|
||
"errors"
|
||
)
|
||
|
||
// AESCipher one of Encryptor implement
|
||
type AESCipher struct {
|
||
key []byte
|
||
iv []byte
|
||
}
|
||
|
||
// NewAESCipher return a AESCipher
|
||
func NewAESCipher(key string) *AESCipher {
|
||
size := len(key) / 8
|
||
if size < 2 {
|
||
//log.Error("incorrect key, need 16(aes-128), 24(aes-192), 32(aes-256) length string")
|
||
return nil
|
||
} else if size > 4 {
|
||
size = 4
|
||
}
|
||
key = key[:size*8]
|
||
return &AESCipher{key: []byte(key), iv: []byte(key[:16])}
|
||
}
|
||
|
||
// Decode src
|
||
func (cipher *AESCipher) Decode(src []byte) []byte {
|
||
encrypt, err := aesDeCrypt(src, cipher.key, cipher.iv)
|
||
if err != nil {
|
||
return src
|
||
}
|
||
return encrypt
|
||
}
|
||
|
||
// Encode src
|
||
func (cipher *AESCipher) Encode(src []byte) []byte {
|
||
encrypt, err := aesEcrypt(src, cipher.key, cipher.iv)
|
||
if err != nil {
|
||
//log.Error("Aes Encode error %s", err)
|
||
return src
|
||
}
|
||
return encrypt
|
||
}
|
||
|
||
//PKCS7 填充模式
|
||
func pKCS7Padding(ciphertext []byte, blockSize int) []byte {
|
||
padding := blockSize - len(ciphertext)%blockSize
|
||
//Repeat()函数的功能是把切片[]byte{byte(padding)}复制padding个，然后合并成新的字节切片返回
|
||
padText := bytes.Repeat([]byte{byte(padding)}, padding)
|
||
return append(ciphertext, padText...)
|
||
}
|
||
|
||
//填充的反向操作，删除填充字符串
|
||
func pKCS7UnPadding(origData []byte) ([]byte, error) {
|
||
//获取数据长度
|
||
length := len(origData)
|
||
if length == 0 {
|
||
return nil, errors.New("pKCS7UnPadding error")
|
||
}
|
||
//获取填充字符串长度
|
||
unpadding := int(origData[length-1])
|
||
//截取切片，删除填充字节，并且返回明文
|
||
return origData[:(length - unpadding)], nil
|
||
}
|
||
|
||
//实现加密
|
||
func aesEcrypt(origData []byte, key, iv []byte) ([]byte, error) {
|
||
//创建加密算法实例
|
||
block, err := aes.NewCipher(key)
|
||
if err != nil {
|
||
return nil, err
|
||
}
|
||
//获取块的大小
|
||
blockSize := block.BlockSize()
|
||
//对数据进行填充，让数据长度满足需求
|
||
origData = pKCS7Padding(origData, blockSize)
|
||
//采用AES加密方法中CBC加密模式
|
||
blocMode := cipher.NewCBCEncrypter(block, iv)
|
||
crypted := make([]byte, len(origData))
|
||
//执行加密
|
||
blocMode.CryptBlocks(crypted, origData)
|
||
return crypted, nil
|
||
}
|
||
|
||
//实现解密
|
||
func aesDeCrypt(cypted []byte, key, iv []byte) ([]byte, error) {
|
||
//创建加密算法实例
|
||
block, err := aes.NewCipher(key)
|
||
if err != nil {
|
||
return nil, err
|
||
}
|
||
//创建加密客户端实例
|
||
blockMode := cipher.NewCBCDecrypter(block, iv)
|
||
origData := make([]byte, len(cypted))
|
||
//这个函数也可以用来解密
|
||
blockMode.CryptBlocks(origData, cypted)
|
||
//去除填充字符串
|
||
origData, err = pKCS7UnPadding(origData)
|
||
if err != nil {
|
||
return nil, err
|
||
}
|
||
return origData, err
|
||
}
|