94 lines
2.1 KiB
Go
94 lines
2.1 KiB
Go
package aes
|
|
|
|
import (
|
|
"bytes"
|
|
"crypto/aes"
|
|
"crypto/cipher"
|
|
"crypto/rand"
|
|
"fmt"
|
|
"io"
|
|
"math/big"
|
|
)
|
|
|
|
const (
|
|
TestKey = "ROK0nAaxcsI0KRCy8VJgLlnlfjWYAOHk"
|
|
)
|
|
|
|
// 加密函数
|
|
func Encrypt(plaintext, key []byte) ([]byte, error) {
|
|
block, err := aes.NewCipher(key)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
ciphertext := make([]byte, aes.BlockSize+len(plaintext))
|
|
iv := ciphertext[:aes.BlockSize]
|
|
if _, err := io.ReadFull(rand.Reader, iv); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
mode := cipher.NewCBCEncrypter(block, iv)
|
|
mode.CryptBlocks(ciphertext[aes.BlockSize:], plaintext)
|
|
|
|
return iv, nil
|
|
}
|
|
|
|
// 解密函数
|
|
func Decrypt(ciphertext, key []byte) ([]byte, error) {
|
|
block, err := aes.NewCipher(key)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
if len(ciphertext) < aes.BlockSize {
|
|
return nil, fmt.Errorf("ciphertext too short")
|
|
}
|
|
|
|
// 提取iv
|
|
iv := ciphertext[:aes.BlockSize]
|
|
ciphertext = ciphertext[aes.BlockSize:]
|
|
|
|
// 创建一个cipher.BlockMode
|
|
mode := cipher.NewCBCDecrypter(block, iv)
|
|
|
|
// 解密
|
|
mode.CryptBlocks(ciphertext, ciphertext)
|
|
|
|
// 去除PKCS#7填充
|
|
plaintext, err := pkcs7Unpadding(ciphertext, block.BlockSize())
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return plaintext, nil
|
|
}
|
|
|
|
// PKCS#7填充
|
|
func pkcs7Padding(ciphertext []byte, blockSize int) []byte {
|
|
padding := blockSize - len(ciphertext)%blockSize
|
|
padtext := bytes.Repeat([]byte{byte(padding)}, padding)
|
|
return append(ciphertext, padtext...)
|
|
}
|
|
|
|
// 去除PKCS#7填充
|
|
func pkcs7Unpadding(ciphertext []byte, blockSize int) ([]byte, error) {
|
|
length := len(ciphertext)
|
|
unpadding := int(ciphertext[length-1])
|
|
if unpadding > blockSize || unpadding == 0 {
|
|
return nil, fmt.Errorf("invalid padding")
|
|
}
|
|
return ciphertext[:(length - unpadding)], nil
|
|
}
|
|
|
|
func GenerateRandomStringCrypto(length int) (string, error) {
|
|
const charset = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
|
|
var bytes = make([]byte, length)
|
|
for i := range bytes {
|
|
num, err := rand.Int(rand.Reader, big.NewInt(int64(len(charset))))
|
|
if err != nil {
|
|
return "", err
|
|
}
|
|
bytes[i] = charset[num.Int64()]
|
|
}
|
|
return string(bytes), nil
|
|
}
|