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aes.go
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aes.go
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package encrypt
import (
"crypto/aes"
"crypto/cipher"
"crypto/rand"
"encoding/base64"
"errors"
"io"
)
var (
// 默认长度
DefaultAesBlockSize = 16
)
// AES ECB模式的加密解密
type AesTool struct {
//128 192 256位的其中一个 长度 对应分别是 16 24 32字节长度
Key []byte
BlockSize int
}
func NewAesTool(key []byte, blockSize int) *AesTool {
return &AesTool{Key: key, BlockSize: blockSize}
}
// EncryptBase64 加密并返回base64编码
func (a *AesTool) Encrypt(plaintext []byte) ([]byte, error) {
block, err := aes.NewCipher(a.Key)
if err != nil {
return nil, err
}
ciphertext := make([]byte, a.BlockSize+len(plaintext))
iv := ciphertext[:a.BlockSize]
if _, err := io.ReadFull(rand.Reader, iv); err != nil {
return nil, err
}
stream := cipher.NewCFBEncrypter(block, iv)
stream.XORKeyStream(ciphertext[a.BlockSize:], plaintext)
// convert to base64
return []byte(base64.URLEncoding.EncodeToString(ciphertext)), nil
}
// Decrypt 从base64编码中返回
func (a *AesTool) Decrypt(src []byte) ([]byte, error) {
ciphertext, err := base64.URLEncoding.DecodeString(string(src))
if err != nil {
return nil, err
}
block, err := aes.NewCipher(a.Key)
if err != nil {
return nil, err
}
// The IV needs to be unique, but not secure. Therefore it's common to
// include it at the beginning of the ciphertext.
if len(ciphertext) < a.BlockSize {
return nil, errors.New("ciphertext too short")
}
iv := ciphertext[:a.BlockSize]
ciphertext = ciphertext[a.BlockSize:]
stream := cipher.NewCFBDecrypter(block, iv)
// XORKeyStream can work in-place if the two arguments are the same.
plaintext := make([]byte, len(ciphertext))
stream.XORKeyStream(plaintext, ciphertext)
return plaintext, nil
}