Question

以下示例有什么问题？

问题是解密字符串的第一部分是无意义的。但是，剩下的很好，我明白了......

Result: `£eB6O�geS��i are you? Have a nice day.

@Test
public void testEncrypt() {
  try {
    String s = "Hello there. How are you? Have a nice day.";

    // Generate key
    KeyGenerator kgen = KeyGenerator.getInstance("AES");
    kgen.init(128);
    SecretKey aesKey = kgen.generateKey();

    // Encrypt cipher
    Cipher encryptCipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
    encryptCipher.init(Cipher.ENCRYPT_MODE, aesKey);

    // Encrypt
    ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
    CipherOutputStream cipherOutputStream = new CipherOutputStream(outputStream, encryptCipher);
    cipherOutputStream.write(s.getBytes());
    cipherOutputStream.flush();
    cipherOutputStream.close();
    byte[] encryptedBytes = outputStream.toByteArray();

    // Decrypt cipher
    Cipher decryptCipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
    IvParameterSpec ivParameterSpec = new IvParameterSpec(aesKey.getEncoded());
    decryptCipher.init(Cipher.DECRYPT_MODE, aesKey, ivParameterSpec);

    // Decrypt
    outputStream = new ByteArrayOutputStream();
    ByteArrayInputStream inStream = new ByteArrayInputStream(encryptedBytes);
    CipherInputStream cipherInputStream = new CipherInputStream(inStream, decryptCipher);
    byte[] buf = new byte[1024];
    int bytesRead;
    while ((bytesRead = cipherInputStream.read(buf)) >= 0) {
        outputStream.write(buf, 0, bytesRead);
    }

    System.out.println("Result: " + new String(outputStream.toByteArray()));

  } 
  catch (Exception ex) {
    ex.printStackTrace();
  }
}

Answer 1

包括我在内的很多人在完成这项工作时面临很多问题，因为缺少一些信息，例如忘记转换为Base64，初始化向量，字符集等等。所以我想到制作一个功能齐全的代码。

希望这对大家都有用：要编译，您需要额外的Apache Commons Codec jar，可在此处获得： http://commons.apache.org/proper/commons-codec/download_codec.cgi

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

import org.apache.commons.codec.binary.Base64;

public class Encryptor {
    public static String encrypt(String key, String initVector, String value) {
        try {
            IvParameterSpec iv = new IvParameterSpec(initVector.getBytes("UTF-8"));
            SecretKeySpec skeySpec = new SecretKeySpec(key.getBytes("UTF-8"), "AES");

            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING");
            cipher.init(Cipher.ENCRYPT_MODE, skeySpec, iv);

            byte[] encrypted = cipher.doFinal(value.getBytes());
            System.out.println("encrypted string: "
                    + Base64.encodeBase64String(encrypted));

            return Base64.encodeBase64String(encrypted);
        } catch (Exception ex) {
            ex.printStackTrace();
        }

        return null;
    }

    public static String decrypt(String key, String initVector, String encrypted) {
        try {
            IvParameterSpec iv = new IvParameterSpec(initVector.getBytes("UTF-8"));
            SecretKeySpec skeySpec = new SecretKeySpec(key.getBytes("UTF-8"), "AES");

            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING");
            cipher.init(Cipher.DECRYPT_MODE, skeySpec, iv);

            byte[] original = cipher.doFinal(Base64.decodeBase64(encrypted));

            return new String(original);
        } catch (Exception ex) {
            ex.printStackTrace();
        }

        return null;
    }

    public static void main(String[] args) {
        String key = "Bar12345Bar12345"; // 128 bit key
        String initVector = "RandomInitVector"; // 16 bytes IV

        System.out.println(decrypt(key, initVector,
                encrypt(key, initVector, "Hello World")));
    }
}

Answer 2

这是一个没有Apache Commons Codec＆＃39; Base64的解决方案：

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

public class AdvancedEncryptionStandard
{
    private byte[] key;

    private static final String ALGORITHM = "AES";

    public AdvancedEncryptionStandard(byte[] key)
    {
        this.key = key;
    }

    /**
     * Encrypts the given plain text
     *
     * @param plainText The plain text to encrypt
     */
    public byte[] encrypt(byte[] plainText) throws Exception
    {
        SecretKeySpec secretKey = new SecretKeySpec(key, ALGORITHM);
        Cipher cipher = Cipher.getInstance(ALGORITHM);
        cipher.init(Cipher.ENCRYPT_MODE, secretKey);

        return cipher.doFinal(plainText);
    }

    /**
     * Decrypts the given byte array
     *
     * @param cipherText The data to decrypt
     */
    public byte[] decrypt(byte[] cipherText) throws Exception
    {
        SecretKeySpec secretKey = new SecretKeySpec(key, ALGORITHM);
        Cipher cipher = Cipher.getInstance(ALGORITHM);
        cipher.init(Cipher.DECRYPT_MODE, secretKey);

        return cipher.doFinal(cipherText);
    }
}

用法示例：

byte[] encryptionKey = "MZygpewJsCpRrfOr".getBytes(StandardCharsets.UTF_8);
byte[] plainText = "Hello world!".getBytes(StandardCharsets.UTF_8);
AdvancedEncryptionStandard advancedEncryptionStandard = new AdvancedEncryptionStandard(
        encryptionKey);
byte[] cipherText = advancedEncryptionStandard.encrypt(plainText);
byte[] decryptedCipherText = advancedEncryptionStandard.decrypt(cipherText);

System.out.println(new String(plainText));
System.out.println(new String(cipherText));
System.out.println(new String(decryptedCipherText));

打印：

Hello world!
դ;��LA+�ߙb*
Hello world!

Answer 3

在我看来，你没有正确处理初始化向量（IV）。自从我上次阅读有关AES，IV和块链接以来，已经有很长一段时间了，但你的行

IvParameterSpec ivParameterSpec = new IvParameterSpec(aesKey.getEncoded());

似乎没有问题。在AES的情况下，您可以将初始化向量视为密码实例的“初始状态”，并且此状态是您无法从密钥获得的一些信息，而是来自加密密码的实际计算。（有人可能会争辩说，如果IV可以从密钥中提取出来，那么它就没有用了，因为在初始阶段密钥已经被赋予密码实例）。

因此，您应该在加密结束时从密码实例中获取IV作为byte []

  cipherOutputStream.close();
  byte[] iv = encryptCipher.getIV();

您应该使用此字节[]初始化Cipher中的DECRYPT_MODE：

  IvParameterSpec ivParameterSpec = new IvParameterSpec(iv);

然后，你的解密应该没问题。希望这会有所帮助。

Answer 4

您用于解密的IV不正确。替换此代码

//Decrypt cipher
Cipher decryptCipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
IvParameterSpec ivParameterSpec = new IvParameterSpec(aesKey.getEncoded());
decryptCipher.init(Cipher.DECRYPT_MODE, aesKey, ivParameterSpec);

使用此代码

//Decrypt cipher
Cipher decryptCipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
IvParameterSpec ivParameterSpec = new IvParameterSpec(encryptCipher.getIV());
decryptCipher.init(Cipher.DECRYPT_MODE, aesKey, ivParameterSpec);

那应该可以解决你的问题。

下面是Java中一个简单AES类的示例。我不建议在生产环境中使用此类，因为它可能无法满足应用程序的所有特定需求。

import java.nio.charset.StandardCharsets;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.util.Base64;

public class AES 
{
    public static byte[] encrypt(final byte[] keyBytes, final byte[] ivBytes, final byte[] messageBytes) throws InvalidKeyException, InvalidAlgorithmParameterException
    {       
        return AES.transform(Cipher.ENCRYPT_MODE, keyBytes, ivBytes, messageBytes);
    }

    public static byte[] decrypt(final byte[] keyBytes, final byte[] ivBytes, final byte[] messageBytes) throws InvalidKeyException, InvalidAlgorithmParameterException
    {       
        return AES.transform(Cipher.DECRYPT_MODE, keyBytes, ivBytes, messageBytes);
    }

    private static byte[] transform(final int mode, final byte[] keyBytes, final byte[] ivBytes, final byte[] messageBytes) throws InvalidKeyException, InvalidAlgorithmParameterException
    {
        final SecretKeySpec keySpec = new SecretKeySpec(keyBytes, "AES");
        final IvParameterSpec ivSpec = new IvParameterSpec(ivBytes);
        byte[] transformedBytes = null;

        try
        {
            final Cipher cipher = Cipher.getInstance("AES/CTR/NoPadding");

            cipher.init(mode, keySpec, ivSpec);

            transformedBytes = cipher.doFinal(messageBytes);
        }        
        catch (NoSuchAlgorithmException | NoSuchPaddingException | IllegalBlockSizeException | BadPaddingException e) 
        {
            e.printStackTrace();
        }
        return transformedBytes;
    }

    public static void main(final String[] args) throws InvalidKeyException, InvalidAlgorithmParameterException
    {
        //Retrieved from a protected local file.
        //Do not hard-code and do not version control.
        final String base64Key = "ABEiM0RVZneImaq7zN3u/w==";

        //Retrieved from a protected database.
        //Do not hard-code and do not version control.
        final String shadowEntry = "AAECAwQFBgcICQoLDA0ODw==:ZtrkahwcMzTu7e/WuJ3AZmF09DE=";

        //Extract the iv and the ciphertext from the shadow entry.
        final String[] shadowData = shadowEntry.split(":");        
        final String base64Iv = shadowData[0];
        final String base64Ciphertext = shadowData[1];

        //Convert to raw bytes.
        final byte[] keyBytes = Base64.getDecoder().decode(base64Key);
        final byte[] ivBytes = Base64.getDecoder().decode(base64Iv);
        final byte[] encryptedBytes = Base64.getDecoder().decode(base64Ciphertext);

        //Decrypt data and do something with it.
        final byte[] decryptedBytes = AES.decrypt(keyBytes, ivBytes, encryptedBytes);

        //Use non-blocking SecureRandom implementation for the new IV.
        final SecureRandom secureRandom = new SecureRandom();

        //Generate a new IV.
        secureRandom.nextBytes(ivBytes);

        //At this point instead of printing to the screen, 
        //one should replace the old shadow entry with the new one.
        System.out.println("Old Shadow Entry      = " + shadowEntry);
        System.out.println("Decrytped Shadow Data = " + new String(decryptedBytes, StandardCharsets.UTF_8));
        System.out.println("New Shadow Entry      = " + Base64.getEncoder().encodeToString(ivBytes) + ":" + Base64.getEncoder().encodeToString(AES.encrypt(keyBytes, ivBytes, decryptedBytes)));
    }
}

请注意，AES与编码无关，这就是我选择单独处理它而不需要任何第三方库的原因。

Answer 5

在这个答案中，我选择以“简单Java AES加密/解密示例”为主题，而不是特定的调试问题，因为我认为这将使大多数读者受益。

这是我的blog post about AES encryption in Java的简单摘要，因此我建议在实施任何内容之前通读它。但是，我仍将提供一个简单的示例，并提供一些注意事项。

在此示例中，我将选择在authenticated encryption模式下使用Galois/Counter Mode or GCM。原因是，在大多数情况下，您需要integrity and authenticity in combination with confidentiality（在blog中了解更多信息）。

AES-GCM加密/解密教程

以下是使用AES-GCM和Java Cryptography Architecture (JCA)进行加密/解密的步骤。 请勿与其他示例混在一起，因为细微的差异可能会使您的代码完全不安全。

1。创建密钥

因为这取决于您的用例，所以我假设最简单的情况是：随机密钥。

SecureRandom secureRandom = new SecureRandom();
byte[] key = new byte[16];
secureRandom.nextBytes(key);
SecretKey secretKey = SecretKeySpec(key, "AES");

重要提示：

始终使用像pseudorandom number generator这样的强SecureRandom
使用16字节/ 128位长的密钥（或更多-but more is seldom needed）
如果您想从用户密码中获取密钥，请像password hash function (or KDF)或stretching property一样用PBKDF2来查找bcrypt
如果要从其他来源派生密钥，请使用适当的key derivation function (KDF)，例如HKDF（Java implementation here）。不要为此使用简单的cryptographic hashes（例如SHA-256）。

2。创建初始化向量

使用initialization vector (IV)，以便同一密钥将创建不同的cipher texts。

byte[] IV = new byte[12]; //NEVER REUSE THIS IV WITH SAME KEY
secureRandom.nextBytes(IV);

重要提示：

永远不要reuse the same IV使用相同的键（在GCM / CTR模式下，非常重要）
IV必须是唯一的（即使用随机IV或计数器）
IV不需要是秘密的
始终使用像pseudorandom number generator这样的强SecureRandom
12字节IV是正确的choice for AES-GCM mode

3。用IV和密钥加密

final Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
GCMParameterSpec parameterSpec = new GCMParameterSpec(128, IV); //128 bit auth tag length
cipher.init(Cipher.ENCRYPT_MODE, secretKey, parameterSpec);
byte[] cipherText = cipher.doFinal(plainText);

重要提示：

使用16字节/ 128位authentication tag（用于验证完整性/真实性）
身份验证标签将自动添加到密文（在JCA实现中）
由于GCM的行为类似于流密码，因此无需填充
加密大块数据时使用CipherInputStream
是否要检查其他（非秘密）数据是否已更改？您可能希望将associated data与cipher.updateAAD(associatedData); More here.

3。序列化为单个消息

只需附加IV和密文。如上所述，IV不必是秘密的。

ByteBuffer byteBuffer = ByteBuffer.allocate(4 + IV.length + cipherText.length);
byteBuffer.putInt(IV.length);
byteBuffer.put(IV);
byteBuffer.put(cipherText);
byte[] cipherMessage = byteBuffer.array();

如果需要字符串表示形式，可以选择用Base64进行编码。使用Android's或Java 8's built-in实现（不要使用Apache Commons Codec，这是一个糟糕的实现）。编码用于将字节数组“转换”为字符串表示形式，以使其成为ASCII安全格式，例如：

String base64CipherMessage = Base64.getEncoder().encodeToString(cipherMessage);

4。准备解密：反序列化

如果您已对消息进行编码，请先将其解码为字节数组：

byte[] cipherMessage = Base64.getDecoder().decode(base64CipherMessage)

然后解构消息

ByteBuffer byteBuffer = ByteBuffer.wrap(cipherMessage);
int ivLength = byteBuffer.getInt();
if(ivLength < 12 || ivLength >= 16) { // check input parameter
    throw new IllegalArgumentException("invalid IV length");
}
byte[] IV = new byte[ivLength];
byteBuffer.get(IV);
byte[] cipherText = new byte[byteBuffer.remaining()];
byteBuffer.get(cipherText);

重要提示：

请谨慎验证input parameters，以免通过分配过多的内存来避免denial of service attacks（例如，攻击者可能将长度值更改为例如2³¹，分配了2GB的堆空间）

5。解密

初始化密码并设置与加密相同的参数：

final Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(key, "AES"), new GCMParameterSpec(128, IV));
byte[] plainText= cipher.doFinal(cipherText);

重要提示：

如果您在加密过程中添加了cipher.updateAAD(associatedData);，请不要忘记将associated data添加到{{1}}中。

请注意，最新的Android（SDK 21+）和Java（7+）实现应具有AES-GCM。旧版本可能缺少它。我仍然选择此模式，因为与Encrypt-then-Mac的类似模式（例如AES-CBC + HMAC）相比，它除了更有效之外，更易于实现。 See this article on how to implement AES-CBC with HMAC。

Answer 6

在线编辑器Runnable版本： -

import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
//import org.apache.commons.codec.binary.Base64;
import java.util.Base64;

public class Encryptor {
    public static String encrypt(String key, String initVector, String value) {
        try {
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING");
            IvParameterSpec iv = new IvParameterSpec(initVector.getBytes("UTF-8"));

            SecretKeySpec skeySpec = new SecretKeySpec(key.getBytes("UTF-8"), "AES");
            cipher.init(Cipher.ENCRYPT_MODE, skeySpec, iv);

            byte[] encrypted = cipher.doFinal(value.getBytes());

            //System.out.println("encrypted string: "
              //      + Base64.encodeBase64String(encrypted));

            //return Base64.encodeBase64String(encrypted);
            String s = new String(Base64.getEncoder().encode(encrypted));
            return s;
        } catch (Exception ex) {
            ex.printStackTrace();
        }
        return null;
    }

    public static String decrypt(String key, String initVector, String encrypted) {
        try {
            IvParameterSpec iv = new IvParameterSpec(initVector.getBytes("UTF-8"));
            SecretKeySpec skeySpec = new SecretKeySpec(key.getBytes("UTF-8"), "AES");

            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING");
            cipher.init(Cipher.DECRYPT_MODE, skeySpec, iv);

            byte[] original = cipher.doFinal(Base64.getDecoder().decode(encrypted));

            return new String(original);
        } catch (Exception ex) {
            ex.printStackTrace();
        }

        return null;
    }

    public static void main(String[] args) {
        String key = "Bar12345Bar12345"; // 128 bit key
        String initVector = "RandomInitVector"; // 16 bytes IV

        System.out.println(encrypt(key, initVector, "Hello World"));
        System.out.println(decrypt(key, initVector, encrypt(key, initVector, "Hello World")));
    }
}

Answer 7

依靠标准库提供的解决方案通常是个好主意：

private static void stackOverflow15554296()
    throws
        NoSuchAlgorithmException, NoSuchPaddingException,        
        InvalidKeyException, IllegalBlockSizeException,
        BadPaddingException
{

    // prepare key
    KeyGenerator keygen = KeyGenerator.getInstance("AES");
    SecretKey aesKey = keygen.generateKey();
    String aesKeyForFutureUse = Base64.getEncoder().encodeToString(
            aesKey.getEncoded()
    );

    // cipher engine
    Cipher aesCipher = Cipher.getInstance("AES/ECB/PKCS5Padding");

    // cipher input
    aesCipher.init(Cipher.ENCRYPT_MODE, aesKey);
    byte[] clearTextBuff = "Text to encode".getBytes();
    byte[] cipherTextBuff = aesCipher.doFinal(clearTextBuff);

    // recreate key
    byte[] aesKeyBuff = Base64.getDecoder().decode(aesKeyForFutureUse);
    SecretKey aesDecryptKey = new SecretKeySpec(aesKeyBuff, "AES");

    // decipher input
    aesCipher.init(Cipher.DECRYPT_MODE, aesDecryptKey);
    byte[] decipheredBuff = aesCipher.doFinal(cipherTextBuff);
    System.out.println(new String(decipheredBuff));
}

打印＆＃34;要编码的文字＆＃34;。

解决方案基于Java Cryptography Architecture Reference Guide和https://stackoverflow.com/a/20591539/146745回答。

Answer 8

这是对已接受答案的改进。

更改：

（1）使用随机IV并将其添加到加密文本之前

（2）使用SHA-256从密码生成密钥

（3）不依赖Apache Commons

public static void main(String[] args) throws GeneralSecurityException {
    String plaintext = "Hello world";
    String passphrase = "My passphrase";
    String encrypted = encrypt(passphrase, plaintext);
    String decrypted = decrypt(passphrase, encrypted);
    System.out.println(encrypted);
    System.out.println(decrypted);
}

private static SecretKeySpec getKeySpec(String passphrase) throws NoSuchAlgorithmException {
    MessageDigest digest = MessageDigest.getInstance("SHA-256");
    return new SecretKeySpec(digest.digest(passphrase.getBytes(UTF_8)), "AES");
}

private static Cipher getCipher() throws NoSuchPaddingException, NoSuchAlgorithmException {
    return Cipher.getInstance("AES/CBC/PKCS5PADDING");
}

public static String encrypt(String passphrase, String value) throws GeneralSecurityException {
    byte[] initVector = new byte[16];
    SecureRandom.getInstanceStrong().nextBytes(initVector);
    Cipher cipher = getCipher();
    cipher.init(Cipher.ENCRYPT_MODE, getKeySpec(passphrase), new IvParameterSpec(initVector));
    byte[] encrypted = cipher.doFinal(value.getBytes());
    return DatatypeConverter.printBase64Binary(initVector) +
            DatatypeConverter.printBase64Binary(encrypted);
}

public static String decrypt(String passphrase, String encrypted) throws GeneralSecurityException {
    byte[] initVector = DatatypeConverter.parseBase64Binary(encrypted.substring(0, 24));
    Cipher cipher = getCipher();
    cipher.init(Cipher.DECRYPT_MODE, getKeySpec(passphrase), new IvParameterSpec(initVector));
    byte[] original = cipher.doFinal(DatatypeConverter.parseBase64Binary(encrypted.substring(24)));
    return new String(original);
}

Answer 9

将java.util.Base64与Spring Boot结合使用的另一种解决方案

加密器类

package com.jmendoza.springboot.crypto.cipher;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import java.nio.charset.StandardCharsets;
import java.util.Base64;

@Component
public class Encryptor {

    @Value("${security.encryptor.key}")
    private byte[] key;
    @Value("${security.encryptor.algorithm}")
    private String algorithm;

    public String encrypt(String plainText) throws Exception {
        SecretKeySpec secretKey = new SecretKeySpec(key, algorithm);
        Cipher cipher = Cipher.getInstance(algorithm);
        cipher.init(Cipher.ENCRYPT_MODE, secretKey);
        return new String(Base64.getEncoder().encode(cipher.doFinal(plainText.getBytes(StandardCharsets.UTF_8))));
    }

    public String decrypt(String cipherText) throws Exception {
        SecretKeySpec secretKey = new SecretKeySpec(key, algorithm);
        Cipher cipher = Cipher.getInstance(algorithm);
        cipher.init(Cipher.DECRYPT_MODE, secretKey);
        return new String(cipher.doFinal(Base64.getDecoder().decode(cipherText)));
    }
}

EncryptorController类

package com.jmendoza.springboot.crypto.controller;

import com.jmendoza.springboot.crypto.cipher.Encryptor;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/cipher")
public class EncryptorController {

    @Autowired
    Encryptor encryptor;

    @GetMapping(value = "encrypt/{value}")
    public String encrypt(@PathVariable("value") final String value) throws Exception {
        return encryptor.encrypt(value);
    }

    @GetMapping(value = "decrypt/{value}")
    public String decrypt(@PathVariable("value") final String value) throws Exception {
        return encryptor.decrypt(value);
    }
}

application.properties

server.port=8082
security.encryptor.algorithm=AES
security.encryptor.key=M8jFt46dfJMaiJA0

示例

http://localhost:8082/cipher/encrypt/jmendoza

2h41HH8Shzc4BRU3hVDOXA ==

http://localhost:8082/cipher/decrypt/2h41HH8Shzc4BRU3hVDOXA==

jmendoza

Github：https://github.com/JonathanM2ndoza/Spring-Boot-Crypto

Answer 10

最终，Java中的加密与Java简化加密（Jasypt）一起使用非常简单，可以用另一种方式使用cypher，上面是一个加密和解密的代码示例：

import java.security.spec.KeySpec;
import java.util.Base64;

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

public class CypherUtils {

    private static final String AES_CBC_PKCS5_PADDING = "AES/CBC/PKCS5Padding";
    private static final String PBKDF2_WITH_HMAC_SHA256 = "PBKDF2WithHmacSHA256";

    public static String decrypt(String strToDecrypt, String keyCode, String salt) {
        try {
            byte[] iv = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
            IvParameterSpec ivspec = new IvParameterSpec(iv);

            SecretKeyFactory factory = SecretKeyFactory.getInstance(PBKDF2_WITH_HMAC_SHA256);
            KeySpec spec = new PBEKeySpec(keyCode.toCharArray(), salt.getBytes(), 65536, 256);
            SecretKey tmp = factory.generateSecret(spec);
            SecretKeySpec secretKey = new SecretKeySpec(tmp.getEncoded(), "AES");

            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING");
            cipher.init(Cipher.DECRYPT_MODE, secretKey, ivspec);
            return new String(cipher.doFinal(Base64.getDecoder().decode(strToDecrypt)));
        } catch (Exception e) {
            System.out.println("Error while decrypting: " + e.toString());
        }
        return null;
    }

    public static String encrypt(String strToEncrypt, String keyCode, String salt) {
        try {
            byte[] iv = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
            IvParameterSpec ivspec = new IvParameterSpec(iv);

            SecretKeyFactory factory = SecretKeyFactory.getInstance(PBKDF2_WITH_HMAC_SHA256);
            KeySpec spec = new PBEKeySpec(keyCode.toCharArray(), salt.getBytes(), 65536, 256);
            SecretKey tmp = factory.generateSecret(spec);
            SecretKeySpec secretKey = new SecretKeySpec(tmp.getEncoded(), "AES");

            Cipher cipher = Cipher.getInstance(AES_CBC_PKCS5_PADDING);
            cipher.init(Cipher.ENCRYPT_MODE, secretKey, ivspec);
            return Base64.getEncoder().encodeToString(cipher.doFinal(strToEncrypt.getBytes("UTF-8")));
        } catch (Exception e) {
            System.out.println("Error while encrypting: " + e.toString());
        }
        return null;
    }
}

Answer 11

已接受答案的优化版本。

没有第三方库
在加密邮件中包含IV（可以公开）
密码可以是任意长度

代码：

import java.io.UnsupportedEncodingException;
import java.security.SecureRandom;
import java.util.Base64;

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

public class Encryptor {
    public static byte[] getRandomInitialVector() {
        try {
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING");
            SecureRandom randomSecureRandom = SecureRandom.getInstance("SHA1PRNG");
            byte[] initVector = new byte[cipher.getBlockSize()];
            randomSecureRandom.nextBytes(initVector);
            return initVector;
        } catch (Exception ex) {
            ex.printStackTrace();
        }
        return null;
    }

    public static byte[] passwordTo16BitKey(String password) {
        try {
            byte[] srcBytes = password.getBytes("UTF-8");
            byte[] dstBytes = new byte[16];

            if (srcBytes.length == 16) {
                return srcBytes;
            }

            if (srcBytes.length < 16) {
                for (int i = 0; i < dstBytes.length; i++) {
                    dstBytes[i] = (byte) ((srcBytes[i % srcBytes.length]) * (srcBytes[(i + 1) % srcBytes.length]));
                }
            } else if (srcBytes.length > 16) {
                for (int i = 0; i < srcBytes.length; i++) {
                    dstBytes[i % dstBytes.length] += srcBytes[i];
                }
            }

            return dstBytes;
        } catch (UnsupportedEncodingException ex) {
            ex.printStackTrace();
        }

        return null;
    }

    public static String encrypt(String key, String value) {
        return encrypt(passwordTo16BitKey(key), value);
    }

    public static String encrypt(byte[] key, String value) {
        try {
            byte[] initVector = Encryptor.getRandomInitialVector();
            IvParameterSpec iv = new IvParameterSpec(initVector);
            SecretKeySpec skeySpec = new SecretKeySpec(key, "AES");

            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING");
            cipher.init(Cipher.ENCRYPT_MODE, skeySpec, iv);

            byte[] encrypted = cipher.doFinal(value.getBytes());
            return Base64.getEncoder().encodeToString(encrypted) + " " + Base64.getEncoder().encodeToString(initVector);
        } catch (Exception ex) {
            ex.printStackTrace();
        }

        return null;
    }

    public static String decrypt(String key, String encrypted) {
        return decrypt(passwordTo16BitKey(key), encrypted);
    }

    public static String decrypt(byte[] key, String encrypted) {
        try {
            String[] encryptedParts = encrypted.split(" ");
            byte[] initVector = Base64.getDecoder().decode(encryptedParts[1]);
            if (initVector.length != 16) {
                return null;
            }

            IvParameterSpec iv = new IvParameterSpec(initVector);
            SecretKeySpec skeySpec = new SecretKeySpec(key, "AES");

            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING");
            cipher.init(Cipher.DECRYPT_MODE, skeySpec, iv);

            byte[] original = cipher.doFinal(Base64.getDecoder().decode(encryptedParts[0]));

            return new String(original);
        } catch (Exception ex) {
            ex.printStackTrace();
        }

        return null;
    }
}

用法：

String key = "Password of any length.";
String encrypted = Encryptor.encrypt(key, "Hello World");
String decrypted = Encryptor.decrypt(key, encrypted);
System.out.println(encrypted);
System.out.println(decrypted);

示例输出：

QngBg+Qc5+F8HQsksgfyXg== yDfYiIHTqOOjc0HRNdr1Ng==
Hello World

Java AES / CBC解密后初始字节不正确

11 个答案:

AES-GCM加密/解密教程

1。创建密钥

2。创建初始化向量

3。用IV和密钥加密

3。序列化为单个消息

4。准备解密：反序列化

5。解密