如何在Java中使用3DES加密/解密？

Question

我用Java编写的所有字符串3DES加密方法都无法解密回原始字符串。有没有简单的代码片段可以对字符串进行加密然后解密回原始字符串？

我知道我在这段代码中犯了一个非常愚蠢的错误。到目前为止，这是我一直在使用的：

**注意，我没有从加密方法返回BASE64文本，并且在解密方法中我没有进行Base64解码，因为我想看看是否在BASE64部分出了问题。

public class TripleDESTest {

    public static void main(String[] args) {

        String text = "kyle boon";

        byte[] codedtext = new TripleDESTest().encrypt(text);
        String decodedtext  = new TripleDESTest().decrypt(codedtext);

        System.out.println(codedtext);
        System.out.println(decodedtext);
    }

    public byte[] encrypt(String message) {
        try {
            final MessageDigest md = MessageDigest.getInstance("md5");
            final byte[] digestOfPassword = md.digest("HG58YZ3CR9".getBytes("utf-8"));
            final byte[] keyBytes = Arrays.copyOf(digestOfPassword, 24);
            for (int j = 0,  k = 16; j < 8;)
            {
                keyBytes[k++] = keyBytes[j++];
            }

            final SecretKey key = new SecretKeySpec(keyBytes, "DESede");
            final IvParameterSpec iv = new IvParameterSpec(new byte[8]);
            final Cipher cipher = Cipher.getInstance("DESede/CBC/PKCS5Padding");
            cipher.init(Cipher.ENCRYPT_MODE, key, iv);

            final byte[] plainTextBytes = message.getBytes("utf-8");
            final byte[] cipherText = cipher.doFinal(plainTextBytes);
            final String encodedCipherText = new sun.misc.BASE64Encoder().encode(cipherText);

            return cipherText;    
        }
        catch (java.security.InvalidAlgorithmParameterException e) { System.out.println("Invalid Algorithm"); }
        catch (javax.crypto.NoSuchPaddingException e) { System.out.println("No Such Padding"); }
        catch (java.security.NoSuchAlgorithmException e) { System.out.println("No Such Algorithm"); }
        catch (java.security.InvalidKeyException e) { System.out.println("Invalid Key"); }
        catch (BadPaddingException e) { System.out.println("Invalid Key");}
        catch (IllegalBlockSizeException e) { System.out.println("Invalid Key");}
        catch (UnsupportedEncodingException e) { System.out.println("Invalid Key");}

        return null;
    }

    public String decrypt(byte[] message) {
        try
        {
            final MessageDigest md = MessageDigest.getInstance("md5");
            final byte[] digestOfPassword = md.digest("HG58YZ3CR9".getBytes("utf-8"));
            final byte[] keyBytes = Arrays.copyOf(digestOfPassword, 24);
            for (int j = 0,  k = 16; j < 8;)
            {
                keyBytes[k++] = keyBytes[j++];
            }

            final SecretKey key = new SecretKeySpec(keyBytes, "DESede");
            final IvParameterSpec iv = new IvParameterSpec(new byte[8]);
            final Cipher decipher = Cipher.getInstance("DESede/CBC/PKCS5Padding");
            decipher.init(Cipher.DECRYPT_MODE, key, iv);

            //final byte[] encData = new sun.misc.BASE64Decoder().decodeBuffer(message);
            final byte[] plainText = decipher.doFinal(message);

            return plainText.toString();            
        }
        catch (java.security.InvalidAlgorithmParameterException e) { System.out.println("Invalid Algorithm"); }
        catch (javax.crypto.NoSuchPaddingException e) { System.out.println("No Such Padding"); }
        catch (java.security.NoSuchAlgorithmException e) { System.out.println("No Such Algorithm"); }
        catch (java.security.InvalidKeyException e) { System.out.println("Invalid Key"); }
        catch (BadPaddingException e) { System.out.println("Invalid Key");}
        catch (IllegalBlockSizeException e) { System.out.println("Invalid Key");}
        catch (UnsupportedEncodingException e) { System.out.println("Invalid Key");}     
        catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        return null;
    }
}

- Kyle Boon

Answer 1

您的代码除了Base 64编码比特之外都没问题（您提到这是一个测试），输出不明确的原因是您显示了一个原始的字节数组（对字节数组执行toString()会返回它的内部Java引用，而不是内容的字符串表示）。以下是稍微清理过的版本，它将"kyle boon"作为解码后的字符串打印出来：

import java.security.MessageDigest;
import java.util.Arrays;

import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;

public class TripleDESTest {

    public static void main(String[] args) throws Exception {

        String text = "kyle boon";

        byte[] codedtext = new TripleDESTest().encrypt(text);
        String decodedtext = new TripleDESTest().decrypt(codedtext);

        System.out.println(codedtext); // this is a byte array, you'll just see a reference to an array
        System.out.println(decodedtext); // This correctly shows "kyle boon"
    }

    public byte[] encrypt(String message) throws Exception {
        final MessageDigest md = MessageDigest.getInstance("md5");
        final byte[] digestOfPassword = md.digest("HG58YZ3CR9"
                .getBytes("utf-8"));
        final byte[] keyBytes = Arrays.copyOf(digestOfPassword, 24);
        for (int j = 0, k = 16; j < 8;) {
            keyBytes[k++] = keyBytes[j++];
        }

        final SecretKey key = new SecretKeySpec(keyBytes, "DESede");
        final IvParameterSpec iv = new IvParameterSpec(new byte[8]);
        final Cipher cipher = Cipher.getInstance("DESede/CBC/PKCS5Padding");
        cipher.init(Cipher.ENCRYPT_MODE, key, iv);

        final byte[] plainTextBytes = message.getBytes("utf-8");
        final byte[] cipherText = cipher.doFinal(plainTextBytes);
        // final String encodedCipherText = new sun.misc.BASE64Encoder()
        // .encode(cipherText);

        return cipherText;
    }

    public String decrypt(byte[] message) throws Exception {
        final MessageDigest md = MessageDigest.getInstance("md5");
        final byte[] digestOfPassword = md.digest("HG58YZ3CR9"
                .getBytes("utf-8"));
        final byte[] keyBytes = Arrays.copyOf(digestOfPassword, 24);
        for (int j = 0, k = 16; j < 8;) {
            keyBytes[k++] = keyBytes[j++];
        }

        final SecretKey key = new SecretKeySpec(keyBytes, "DESede");
        final IvParameterSpec iv = new IvParameterSpec(new byte[8]);
        final Cipher decipher = Cipher.getInstance("DESede/CBC/PKCS5Padding");
        decipher.init(Cipher.DECRYPT_MODE, key, iv);

        // final byte[] encData = new
        // sun.misc.BASE64Decoder().decodeBuffer(message);
        final byte[] plainText = decipher.doFinal(message);

        return new String(plainText, "UTF-8");
    }
}

- Boris Terzic

---

非常感谢。但实际上，这种方法只使用两个密钥来加密消息：“HG58YZ3CR9”和“IvParameterSpec iv = new IvParameterSpec(new byte[8]);”。但是，最强的三重DES选项可以使用三个不同的密钥来加密消息。那么该怎么做呢？我在Cipher中找到了一种方法，它使用“SecureRandom”作为另一个参数。所以这是正确的方法吗？非常感谢。 - Marshal Chen

3DES使用3个8字节密钥（在此示例中存储为24字节）。通常第1个和第3个密钥相同（即通过取双长度16字节密钥，您可以将第一个组件重复使用作为第三个组件）。要使用三倍长度密钥，只需跳过上面的位，其中将第一个组件（字节0-7）复制到第三个组件的空间（字节16-23）。 - Adrian Hope-Bailie

@AdrianHope-Bailie，这个建议是错误的，因为MD5只输出16个字节，所以其余部分将被填充为零。仅仅用零永远不会成为一个好的密钥。 - Maarten Bodewes

这段代码的问题在于它使用了一个静态的零字节 IV。更好的方法是为每个加密生成一个随机的 IV，并将其存储在密文开头。它不需要保密，但需要是不可预测的。 - Artjom B.

如何将密文转换为字符串？ - Panadol Chong

Answer 2

以下是使用javax.crypto库和Apache Commons Codec库进行Base64编解码的解决方案：

import java.security.spec.KeySpec;
import javax.crypto.Cipher;
import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESedeKeySpec;
import org.apache.commons.codec.binary.Base64;

public class TrippleDes {

    private static final String UNICODE_FORMAT = "UTF8";
    public static final String DESEDE_ENCRYPTION_SCHEME = "DESede";
    private KeySpec ks;
    private SecretKeyFactory skf;
    private Cipher cipher;
    byte[] arrayBytes;
    private String myEncryptionKey;
    private String myEncryptionScheme;
    SecretKey key;

    public TrippleDes() throws Exception {
        myEncryptionKey = "ThisIsSpartaThisIsSparta";
        myEncryptionScheme = DESEDE_ENCRYPTION_SCHEME;
        arrayBytes = myEncryptionKey.getBytes(UNICODE_FORMAT);
        ks = new DESedeKeySpec(arrayBytes);
        skf = SecretKeyFactory.getInstance(myEncryptionScheme);
        cipher = Cipher.getInstance(myEncryptionScheme);
        key = skf.generateSecret(ks);
    }


    public String encrypt(String unencryptedString) {
        String encryptedString = null;
        try {
            cipher.init(Cipher.ENCRYPT_MODE, key);
            byte[] plainText = unencryptedString.getBytes(UNICODE_FORMAT);
            byte[] encryptedText = cipher.doFinal(plainText);
            encryptedString = new String(Base64.encodeBase64(encryptedText));
        } catch (Exception e) {
            e.printStackTrace();
        }
        return encryptedString;
    }


    public String decrypt(String encryptedString) {
        String decryptedText=null;
        try {
            cipher.init(Cipher.DECRYPT_MODE, key);
            byte[] encryptedText = Base64.decodeBase64(encryptedString);
            byte[] plainText = cipher.doFinal(encryptedText);
            decryptedText= new String(plainText);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return decryptedText;
    }


    public static void main(String args []) throws Exception
    {
        TrippleDes td= new TrippleDes();

        String target="imparator";
        String encrypted=td.encrypt(target);
        String decrypted=td.decrypt(encrypted);

        System.out.println("String To Encrypt: "+ target);
        System.out.println("Encrypted String:" + encrypted);
        System.out.println("Decrypted String:" + decrypted);

    }

}

运行上面的程序将得到以下输出：

String To Encrypt: imparator
Encrypted String:FdBNaYWfjpWN9eYghMpbRA==
Decrypted String:imparator

- oneiros

---

这个答案解决了问题，但是代码引入了所有编码、模式等错误，需要在问题的代码中小心避免。 - Maarten Bodewes

谢谢你的回答。有一个问题，如果密钥长度小于24字节，我该如何正确解决这个问题？ - Salvo

key = skf.generateSecret(ks); 这里我们正在生成一个用于加密的密钥，对吧？那么 myEncryptionKey 到底是什么？ - artur47wien

当我用我的字符串替换上面的加密字符串并用我的密钥替换密钥时，这似乎对我不起作用。我得到了输入长度不是8的因子异常。 - GSUgambit

Answer 3

我曾经很费解，但这篇文章帮助我找到了适合我情况的正确答案。在使用金融信息交换标准ISO-8583时，对于3DES的要求非常具体，因此对于我的特殊情况，“DESede/CBC/PKCS5Padding”组合并不能解决问题。经过一些与金融界设计的一些3DES计算器的结果比较测试之后，我发现“DESede/ECB/Nopadding”更适合于特定任务。

这里是我的TripleDes类（使用Bouncy Castle提供程序）的演示实现。

    import java.security.InvalidKeyException;
    import java.security.NoSuchAlgorithmException;
    import java.security.NoSuchProviderException;
    import java.security.Security;
    import javax.crypto.BadPaddingException;
    import javax.crypto.Cipher;
    import javax.crypto.IllegalBlockSizeException;
    import javax.crypto.NoSuchPaddingException;
    import javax.crypto.SecretKey;
    import javax.crypto.spec.SecretKeySpec;
    import org.bouncycastle.jce.provider.BouncyCastleProvider;


    /**
     *
     * @author Jose Luis Montes de Oca
     */
    public class TripleDesCipher {
       private static String TRIPLE_DES_TRANSFORMATION = "DESede/ECB/Nopadding";
       private static String ALGORITHM = "DESede";
       private static String BOUNCY_CASTLE_PROVIDER = "BC";
       private Cipher encrypter;
       private Cipher decrypter;

       public TripleDesCipher(byte[] key) throws NoSuchAlgorithmException, NoSuchProviderException, NoSuchPaddingException,
             InvalidKeyException {
          Security.addProvider(new BouncyCastleProvider());
          SecretKey keySpec = new SecretKeySpec(key, ALGORITHM);
          encrypter = Cipher.getInstance(TRIPLE_DES_TRANSFORMATION, BOUNCY_CASTLE_PROVIDER);
          encrypter.init(Cipher.ENCRYPT_MODE, keySpec);
          decrypter = Cipher.getInstance(TRIPLE_DES_TRANSFORMATION, BOUNCY_CASTLE_PROVIDER);
          decrypter.init(Cipher.DECRYPT_MODE, keySpec);
       }

       public byte[] encode(byte[] input) throws IllegalBlockSizeException, BadPaddingException {
          return encrypter.doFinal(input);
       }

       public byte[] decode(byte[] input) throws IllegalBlockSizeException, BadPaddingException {
          return decrypter.doFinal(input);
       }
    }

- jlmontesdeoca

---

仅仅提供任何3DES代码对我来说似乎不是一个答案。此外，显式使用ECB和NoPadding，并在不真正需要的情况下使用BC，我认为这个答案是不合格的。 - Maarten Bodewes

非常感谢 @jlmontesdeoca。你的回答节省了我的时间。我也被 PKCS7Padding 卡住了。 - Tahir Mehmood

Answer 4

这是一个非常简单的静态加密/解密类，基于Jose Luis Montes de Oca的Bouncy Castle无填充示例。它使用“DESede/ECB/PKCS7Padding”，因此无需手动补位。

    package com.zenimax.encryption;

    import java.security.InvalidKeyException;
    import java.security.NoSuchAlgorithmException;
    import java.security.NoSuchProviderException;
    import java.security.Security;
    import javax.crypto.BadPaddingException;
    import javax.crypto.Cipher;
    import javax.crypto.IllegalBlockSizeException;
    import javax.crypto.NoSuchPaddingException;
    import javax.crypto.SecretKey;
    import javax.crypto.spec.SecretKeySpec;
    import org.bouncycastle.jce.provider.BouncyCastleProvider;

    /**
     * 
     * 作者：Matthew H. Wagner
     */
    public class TripleDesBouncyCastle {
        // 算法名称/加密模式/填充方式
        private static String TRIPLE_DES_TRANSFORMATION = "DESede/ECB/PKCS7Padding";
        private static String ALGORITHM = "DESede";
        private static String BOUNCY_CASTLE_PROVIDER = "BC";

        private static void init()
        {
            // 添加Bouncy Castle提供程序
            Security.addProvider(new BouncyCastleProvider());
        }

        public static byte[] encode(byte[] input, byte[] key)
                throws IllegalBlockSizeException, BadPaddingException,
                NoSuchAlgorithmException, NoSuchProviderException,
                NoSuchPaddingException, InvalidKeyException {
            init();
            SecretKey keySpec = new SecretKeySpec(key, ALGORITHM);
            Cipher encrypter = Cipher.getInstance(TRIPLE_DES_TRANSFORMATION,
                    BOUNCY_CASTLE_PROVIDER);
            encrypter.init(Cipher.ENCRYPT_MODE, keySpec);
            return encrypter.doFinal(input);
        }

        public static byte[] decode(byte[] input, byte[] key)
                throws IllegalBlockSizeException, BadPaddingException,
                NoSuchAlgorithmException, NoSuchProviderException,
                NoSuchPaddingException, InvalidKeyException {
            init();
            SecretKey keySpec = new SecretKeySpec(key, ALGORITHM);
            Cipher decrypter = Cipher.getInstance(TRIPLE_DES_TRANSFORMATION,
                    BOUNCY_CASTLE_PROVIDER);
            decrypter.init(Cipher.DECRYPT_MODE, keySpec);
            return decrypter.doFinal(input);
        }
    }

- siliconsmiley

---

但它仍然使用ECB，这是一个更大的错误。 - Maarten Bodewes

Answer 5

private static final String UNICODE_FORMAT = "UTF8";
private static final String DESEDE_ENCRYPTION_SCHEME = "DESede";
private KeySpec ks;
private SecretKeyFactory skf;
private Cipher cipher;
byte[] arrayBytes;
private String encryptionSecretKey = "ThisIsSpartaThisIsSparta";
SecretKey key;

public TripleDesEncryptDecrypt() throws Exception {
    convertStringToSecretKey(encryptionSecretKey);
}

public TripleDesEncryptDecrypt(String encryptionSecretKey) throws Exception {
    convertStringToSecretKey(encryptionSecretKey);
}

public SecretKey convertStringToSecretKey (String encryptionSecretKey) throws Exception {
    arrayBytes = encryptionSecretKey.getBytes(UNICODE_FORMAT);
    ks = new DESedeKeySpec(arrayBytes);
    skf = SecretKeyFactory.getInstance(DESEDE_ENCRYPTION_SCHEME);
    cipher = Cipher.getInstance(DESEDE_ENCRYPTION_SCHEME);
    key = skf.generateSecret(ks);
    return key;
}

/**
 * Encrypt without specifying secret key
 * 
 * @param unencryptedString
 * @return String
 */
public String encrypt(String unencryptedString) {
    String encryptedString = null;
    try {
        cipher.init(Cipher.ENCRYPT_MODE, key);
        byte[] plainText = unencryptedString.getBytes(UNICODE_FORMAT);
        byte[] encryptedText = cipher.doFinal(plainText);
        encryptedString = new String(Base64.encodeBase64(encryptedText));
    } catch (Exception e) {
        e.printStackTrace();
    }
    return encryptedString;
}

/**
 * Encrypt with specified secret key
 * 
 * @param unencryptedString
 * @return String
 */
public String encrypt(String encryptionSecretKey, String unencryptedString) {
    String encryptedString = null;
    try {
        key = convertStringToSecretKey(encryptionSecretKey);
        cipher.init(Cipher.ENCRYPT_MODE, key);
        byte[] plainText = unencryptedString.getBytes(UNICODE_FORMAT);
        byte[] encryptedText = cipher.doFinal(plainText);
        encryptedString = new String(Base64.encodeBase64(encryptedText));
    } catch (Exception e) {
        e.printStackTrace();
    }
    return encryptedString;
}


/**
 * Decrypt without specifying secret key
 * @param encryptedString
 * @return
 */
public String decrypt(String encryptedString) {
    String decryptedText=null;
    try {
        cipher.init(Cipher.DECRYPT_MODE, key);
        byte[] encryptedText = Base64.decodeBase64(encryptedString);
        byte[] plainText = cipher.doFinal(encryptedText);
        decryptedText= new String(plainText);
    } catch (Exception e) {
        e.printStackTrace();
    }
    return decryptedText;
}

/**
 * Decrypt with specified secret key
 * @param encryptedString
 * @return
 */
public String decrypt(String encryptionSecretKey, String encryptedString) {
    String decryptedText=null;
    try {
        key = convertStringToSecretKey(encryptionSecretKey);
        cipher.init(Cipher.DECRYPT_MODE, key);
        byte[] encryptedText = Base64.decodeBase64(encryptedString);
        byte[] plainText = cipher.doFinal(encryptedText);
        decryptedText= new String(plainText);
    } catch (Exception e) {
        e.printStackTrace();
    }
    return decryptedText;
}

- Ayomide Joysbright Oyediran

---

加强了 @oniero 的代码，这可以帮助您使用喜欢的密钥一次初始化类并能够进行解密和加密。主要方法未添加，因此您可以添加主要方法或复制 oniero 的主要方法。 - Ayomide Joysbright Oyediran

你的回答可以通过提供更多支持信息来改进。请[编辑]以添加进一步细节，例如引用或文献，以便其他人可以确认你的答案是否正确。你可以在帮助中心找到有关如何撰写良好答案的更多信息。 - Community

Answer 6

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.security.Key;
import javax.crypto.Cipher;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.DESedeKeySpec;
import javax.crypto.spec.IvParameterSpec;
import java.util.Base64;
import java.util.Base64.Encoder;


/**
 * 
 * @author shivshankar pal
 * 
 *         this code is working properly. doing proper encription and decription
           note:- it will work only with jdk8

 * 

 * 
 */

public class TDes {
    private static byte[] key = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
            0x00, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x02, 0x02,
            0x02, 0x02, 0x02, 0x02, 0x02, 0x02 };

    private static byte[] keyiv = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
            0x00 };



     public static String encode(String args) {


        System.out.println("plain data==>  " + args);

        byte[] encoding;
        try {
            encoding = Base64.getEncoder().encode(args.getBytes("UTF-8"));

        System.out.println("Base64.encodeBase64==>" + new String(encoding));
        byte[] str5 = des3EncodeCBC(key, keyiv, encoding);

        System.out.println("des3EncodeCBC==>  " + new String(str5));

        byte[] encoding1 = Base64.getEncoder().encode(str5);
        System.out.println("Base64.encodeBase64==> " + new String(encoding1));
        return new String(encoding1);
        } catch (UnsupportedEncodingException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return null;
    }


    public static String decode(String args) {
        try {
            System.out.println("encrypted data==>" + new String(args.getBytes("UTF-8")));


        byte[] decode = Base64.getDecoder().decode(args.getBytes("UTF-8"));
        System.out.println("Base64.decodeBase64(main encription)==>" + new String(decode));

        byte[] str6 = des3DecodeCBC(key, keyiv, decode);
        System.out.println("des3DecodeCBC==>" + new String(str6));
        String data=new String(str6);
        byte[] decode1 = Base64.getDecoder().decode(data.trim().getBytes("UTF-8"));
        System.out.println("plaintext==>  " + new String(decode1));
        return new String(decode1);
        } catch (UnsupportedEncodingException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return "u mistaken in try block";

        }



    private static byte[] des3EncodeCBC(byte[] key, byte[] keyiv, byte[] data) {
        try {
            Key deskey = null;
            DESedeKeySpec spec = new DESedeKeySpec(key);
            SecretKeyFactory keyfactory = SecretKeyFactory.getInstance("desede");
            deskey = keyfactory.generateSecret(spec);

            Cipher cipher = Cipher.getInstance("desede/ CBC/PKCS5Padding");
            IvParameterSpec ips = new IvParameterSpec(keyiv);
            cipher.init(Cipher.ENCRYPT_MODE, deskey, ips);
            byte[] bout = cipher.doFinal(data);
            return bout;

        } catch (Exception e) {
            System.out.println("methods qualified name" + e);
        }
        return null;

    }

    private static byte[] des3DecodeCBC(byte[] key, byte[] keyiv, byte[] data) {
        try {
            Key deskey = null;
            DESedeKeySpec spec = new DESedeKeySpec(key);
            SecretKeyFactory keyfactory = SecretKeyFactory.getInstance("desede");
            deskey = keyfactory.generateSecret(spec);

            Cipher cipher = Cipher.getInstance("desede/ CBC/NoPadding");//PKCS5Padding NoPadding
            IvParameterSpec ips = new IvParameterSpec(keyiv);
            cipher.init(Cipher.DECRYPT_MODE, deskey, ips);

            byte[] bout = cipher.doFinal(data);


            return bout;

        } catch (Exception e) {
            System.out.println("methods qualified name" + e);
        }

        return null;

    }

}

- shiv