使用AES-CBC-PKCS5Padding解密数据时出现填充错误

Question

我编写了如下两个函数对数据进行加密和解密。

public static void encrypt() throws Exception {
    // Add the BouncyCastle Provider
    //Security.addProvider(new BouncyCastleProvider());

// Generate the key
byte[] keyBytes = "AAAAAAAAAAAAAAAA".getBytes();
SecretKeySpec   key = new SecretKeySpec(keyBytes, "AES");
// Generate the IV
byte[] ivBytes  = "AAAAAAAAAAAAAAAA".getBytes();
IvParameterSpec ivSpec = new IvParameterSpec(ivBytes);
// Create the cipher object and initialize it
Cipher          cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, key, ivSpec);
// Read all bytes from a file into a bytes array
byte[] inputBytes = GCM.readFile("input");
byte[] cipherBytes = cipher.doFinal(inputBytes);
BufferedOutputStream  outputStream = new BufferedOutputStream(new FileOutputStream("output.enc"));
outputStream.write(cipherBytes);
outputStream.close();   
}
public static void decrypt() throws Exception {
    // Add the BouncyCastle Provider
     //Security.addProvider(new BouncyCastleProvider());
 // Generate the key
 byte[] keyBytes = "AAAAAAAAAAAAAAAA".getBytes();
 SecretKeySpec   key = new SecretKeySpec(keyBytes, "AES");
 // Generate the IV
 byte[] ivBytes  = "AAAAAAAAAAAAAAAA".getBytes();
 IvParameterSpec ivSpec = new IvParameterSpec(ivBytes);
 // Create the cipher object and initialize it
 Cipher          cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
 cipher.init(Cipher.DECRYPT_MODE, key, ivSpec);
 // Read all bytes from a file into a bytes array
 byte[] cipherBytes = GCM.readFile("ouput.enc");
 byte[] decBytes = cipher.doFinal(cipherBytes);
 BufferedOutputStream  outputStream = new BufferedOutputStream(new FileOutputStream("regen.plain"));
 outputStream.write(decBytes);
 outputStream.close();   
}

我意识到代码的键集为"AAAAAAAAAAAAAAAA".getBytes();但是，请原谅我，因为这只是一个例子。

当我运行程序时，我得到以下堆栈跟踪:-

Exception in thread "main" javax.crypto.IllegalBlockSizeException: Input length must be multiple of 16 when decrypting with padded cipher
    at com.sun.crypto.provider.SunJCE_f.b(DashoA13*..)
    at com.sun.crypto.provider.SunJCE_f.b(DashoA13*..)
    at com.sun.crypto.provider.AESCipher.engineDoFinal(DashoA13*..)
    at javax.crypto.Cipher.doFinal(DashoA13*..)
    at GCM.decrypt(GCM.java:80)
    at GCM.main(GCM.java:90)

我很难弄清楚为什么我遇到这个错误。有什么提示我如何解决这个问题吗?

[编辑]似乎当我写数据时有16个字节，但只有15个字节当我读回来。

Answer 1

关于你的更新:嗯，那很容易，修复读取文件的部分，因为密文需要是N *块大小，因此16字节。我没有看到任何明显的错误

Answer 2

可能的问题(除非是打字错误)您写入output.enc但读取ouput.enc