103 lines
2.2 KiB
Go
103 lines
2.2 KiB
Go
package mycrypto
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import (
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"bytes"
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"crypto/aes"
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"crypto/cipher"
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"encoding/hex"
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"fmt"
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)
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var (
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defaultAes256Cbc *Aes256Cbc
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)
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type Aes256Cbc struct {
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Iv []byte // iv向量 (key 32字节 256位)
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Key []byte // 加密密钥 (iv 16字节 128位)
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}
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func NewAes256Cbc(key, iv string) *Aes256Cbc {
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if len(key) != 32 {
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panic("密钥key长度应为32")
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}
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if len(iv) != aes.BlockSize {
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panic("iv长度应为16")
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}
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return &Aes256Cbc{
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Iv: []byte(iv),
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Key: []byte(key),
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}
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}
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func InitAes256Cbc(key, iv string) {
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defaultAes256Cbc = NewAes256Cbc(key, iv)
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}
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func Aes256CbcEncrypt(plainText string) (string, error) {
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return defaultAes256Cbc.Encrypt(plainText)
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}
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func Aes256CbcDecrypt(cipherText string) (string, error) {
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return defaultAes256Cbc.Decrypt(cipherText)
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}
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// Encrypt 加密
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func (a *Aes256Cbc) Encrypt(plainText string) (res string, err error) {
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defer func() {
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if err2 := recover(); err2 != nil {
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err = fmt.Errorf("panic: %s", err2)
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}
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}()
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// PKCS5填充，补齐数据块
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bPlaintext := a.PKCS5Padding([]byte(plainText), aes.BlockSize)
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block, err := aes.NewCipher(a.Key)
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if err != nil {
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return plainText, err
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}
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ciphertext := make([]byte, len(bPlaintext))
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mode := cipher.NewCBCEncrypter(block, a.Iv)
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mode.CryptBlocks(ciphertext, bPlaintext)
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return hex.EncodeToString(ciphertext), nil
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}
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// Decrypt 解密
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func (a *Aes256Cbc) Decrypt(cipherText string) (res string, err error) {
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defer func() {
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if err2 := recover(); err2 != nil {
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err = fmt.Errorf("panic: %s", err2)
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}
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}()
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block, err := aes.NewCipher(a.Key)
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if err != nil {
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return "", err
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}
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decodeString, err := hex.DecodeString(cipherText)
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if err != nil {
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return "", err
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}
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mode := cipher.NewCBCDecrypter(block, a.Iv)
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mode.CryptBlocks(decodeString, decodeString)
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// 移除多余填充的补充位
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return string(a.PKCS5UnPadding(decodeString)), nil
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}
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func (a *Aes256Cbc) PKCS5Padding(ciphertext []byte, blockSize int) []byte {
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padding := blockSize - len(ciphertext)%blockSize
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padtext := bytes.Repeat([]byte{byte(padding)}, padding)
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return append(ciphertext, padtext...)
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}
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func (a *Aes256Cbc) PKCS5UnPadding(src []byte) []byte {
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length := len(src)
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unpadding := int(src[length-1])
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return src[:(length - unpadding)]
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}
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