54 lines
1.2 KiB
Go
54 lines
1.2 KiB
Go
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package utils
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import (
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"crypto/aes"
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"encoding/base64"
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"fmt"
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"regexp"
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)
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// 解密函数
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func Decrypt(ciphertext string, key []byte) (string, error) {
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// Base64 解码
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cipherTextDecoded, err := base64.StdEncoding.DecodeString(ciphertext)
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if err != nil {
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return "", err
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}
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// 创建 AES 密码块
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block, err := aes.NewCipher(key)
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if err != nil {
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return "", err
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}
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// 检查密文长度是否为块大小的倍数
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if len(cipherTextDecoded)%aes.BlockSize != 0 {
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return "", fmt.Errorf("密文长度不是块大小的倍数")
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}
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// 解密密文
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decrypted := make([]byte, len(cipherTextDecoded))
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for bs := 0; bs < len(cipherTextDecoded); bs += aes.BlockSize {
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block.Decrypt(decrypted[bs:], cipherTextDecoded[bs:bs+aes.BlockSize])
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}
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// 移除填充
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decrypted = pkcs7Unpad(decrypted)
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// 移除不需要的字符
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re := regexp.MustCompile("[\\x00-\\x08\\x0b-\\x0c\\x0e-\\x1f\n\r\t]")
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cleanedString := re.ReplaceAllString(string(decrypted), "")
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return cleanedString, nil
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}
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// 移除PKCS7填充
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func pkcs7Unpad(src []byte) []byte {
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length := len(src)
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unpadding := int(src[length-1])
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if unpadding > length {
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return src
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}
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return src[:(length - unpadding)]
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}
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