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我正在尝试使用 TrippleDES 算法加密和解密字符串，而不使用 Base64 编码（我的应用程序将与具有这些要求的另一个应用程序通信）。当我使用 Base64 编码/解码测试东西时，一切都运行良好，但是当我切换到纯文本样式（比如我调用的应用程序需要）时，一切都坏了。

我读过这篇文章Given final block not proper padded，这说明解码时密钥错误，但这不可能，因为这些行实际上为密钥和转换传递了相同的变量：

ecipher = Cipher.getInstance(transformation);
dcipher = Cipher.getInstance(transformation);
ecipher.init(Cipher.ENCRYPT_MODE, key, iv);
dcipher.init(Cipher.DECRYPT_MODE, key, iv);

另外，我打印了编码字符串和数组的长度，它们的长度是 8 的倍数。

我得到的输出是：

originalText: Abcdefgh
number of bites: 16
cryptText: d4167d9e2b3b1b2d1f940bc45099da0a
cryptText.length: 32
cryptText.getBytes().length: 32
Exception in thread "main" javax.crypto.BadPaddingException: Given final block not properly padded
    at com.sun.crypto.provider.SunJCE_f.b(DashoA13*..)
    at com.sun.crypto.provider.SunJCE_f.b(DashoA13*..)
    at com.sun.crypto.provider.DESedeCipher.engineDoFinal(DashoA13*..)
    at javax.crypto.Cipher.doFinal(DashoA13*..)
Java Result: 1

我的完整代码（本教程稍作修改的版本http://eternusuk.blogspot.com/2008/09/java-triple-des-example.html）：

package com.test.encrypt;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESedeKeySpec;
import javax.crypto.spec.IvParameterSpec;
import org.apache.commons.codec.binary.Hex;

public class TrippleDESTest
{
    private Cipher ecipher;
    private Cipher dcipher;
    private String algorithm = "DESede";
    private String transformation = "DESede/CBC/PKCS5Padding";
    private String keyPhrase = "123456789012345678901234"; //your keyphrase 24 bit
    private SecretKey key;
    private IvParameterSpec iv;
    private static TrippleDESTest cryptoUtil;
    private String ENCODING = "UTF-8";

    public static TrippleDESTest getInstance() throws Exception
    {
        if (cryptoUtil == null)
        {
            cryptoUtil = new TrippleDESTest();
        }

        return cryptoUtil;
    }

    private TrippleDESTest() throws Exception
    {
            DESedeKeySpec keySpec = new DESedeKeySpec(keyPhrase.getBytes());
            key = SecretKeyFactory.getInstance(algorithm).generateSecret(keySpec);
            iv = new IvParameterSpec(new byte[8]);
            ecipher = Cipher.getInstance(transformation);
            dcipher = Cipher.getInstance(transformation);
            ecipher.init(Cipher.ENCRYPT_MODE, key, iv);
            dcipher.init(Cipher.DECRYPT_MODE, key, iv);
    }

    public String encrypt(String str) throws Exception
    {
            byte[] utf8 = str.getBytes(ENCODING);    
            byte[] enc = ecipher.doFinal(utf8);                
            System.out.println("number of bites: " + enc.length);    
            return Hex.encodeHexString(enc);
    }

    public String decrypt(String str) throws Exception
    {
            byte[] dec = str.getBytes();
            byte[] utf8 = dcipher.doFinal(dec);    
            return Hex.encodeHexString(utf8);
    }

    public static void main(String[] args) throws Exception
    {
        TrippleDESTest test = TrippleDESTest.getInstance();        
        String originalText = "Abcdefgh";        
        System.out.println("originalText: " + originalText);        
        String cryptText = test.encrypt(originalText);        
        System.out.println("cryptText: " + cryptText);        
        System.out.println("cryptText.length: " + cryptText.length());
        System.out.println("cryptText.getBytes().length: " + cryptText.getBytes().length);        
        System.out.println("decote text: " + test.decrypt(cryptText));

    }
}// end class TrippleDESTest

提前致谢！

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1 回答 1

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您以错误的顺序执行十六进制编码。您需要对密文进行解码，而不是在您的decrypt方法中对纯文本进行编码。

于 2013-02-21T01:11:44.300 回答