AES 256加密-Qt等效于Java

Question

我已经实现了我的AES 256加密方法，并且可以在Java中正常工作，如下所示！

  private static final byte[] IV = {
    0, 2, 4, 8, 16, 32, 64, 127, 
    127, 64, 32, 16, 8, 4, 2, 0
};

  //actual encryption over here
  private static byte[] encrypt(byte[] raw, byte[] clear) throws 
Exception {  
    SecretKeySpec skeySpec = new SecretKeySpec(raw,  "AES");  
    Cipher cipher = null;

    if(isIVUsedForCrypto) {
        cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
        cipher.init(Cipher.ENCRYPT_MODE, skeySpec, new IvParameterSpec(IV));  
    }
    else 
    {
        cipher = Cipher.getInstance("AES");
        cipher.init(Cipher.ENCRYPT_MODE, skeySpec);  
    }
    byte[] encrypted = cipher.doFinal(clear);  
    return encrypted;  
}  

从上述方法返回的字节数组最终使用以下toHex方法转换为HEX字符串。

      public static String toHex(byte[] buf) {  
    if (buf == null)  
        return "";  
    StringBuffer result = new StringBuffer(2*buf.length);  
    for (int i = 0; i < buf.length; i++) {  
        appendHex(result, buf[i]);  
    }  
    return result.toString();  
}  
private final static String HEX = "0123456789ABCDEF";  
private static void appendHex(StringBuffer sb, byte b) {  
    sb.append(HEX.charAt((b>>4)&0x0f)).append(HEX.charAt(b&0x0f));  
}  

因此，使用Java AES 256加密代码的最终结果是十六进制字符串。

现在在Qt部分，

  QByteArray IV("0, 2, 4, 8, 16, 32, 64, 127,127, 64, 32, 16, 8, 4, 2, 0");


 QString encrypt(QByteArray r, const QString &password)
 {
const char *sample = r.data();
string plain = password.toStdString();
string ciphertext;
// Generate Cipher, Key, and CBC
byte key[ AES::MAX_KEYLENGTH ], iv[ AES::BLOCKSIZE ];
StringSource( reinterpret_cast<const char *>(sample), true,
              new HashFilter(*(new SHA256), new ArraySink(key, AES::MAX_KEYLENGTH)) );
memset( iv, 0x00, AES::BLOCKSIZE );
CBC_Mode<AES>::Encryption Encryptor( key, sizeof(key), iv );
StringSource( plain, true, new StreamTransformationFilter( Encryptor,
              new HexEncoder(new StringSink( ciphertext ) ) ) );
return QString::fromStdString(ciphertext);
} 

从主要方法中我调用上面的函数

        QString encrypted = encrypt(result, "test");

此处的“结果”是QByteArray我传递给加密的，就像在Java中一样。

在Java和Qt两种情况下，字节数组都获得相同的值。我已经证实了。

我的问题

特别是Qt的加密逻辑在某处失败，这是HEX因为通过Java和Qt获得的结果不匹配。

谁能告诉我我在Qt部分做错了什么。我没有正确使用IV或QByteArray result吗？

Answer 1

我猜你的 Java 实现错过了密钥上的哈希步骤。我正在使用密钥的 SHA256 哈希值。要测试 C++ 实现，请将代码更改为：

QString encrypt(QByteArray r, const QString &password)
 {
const char *sample = r.data();
string plain = password.toStdString();
string ciphertext;
// Generate Cipher, Key, and CBC
byte key[ AES::MAX_KEYLENGTH ], iv[ AES::BLOCKSIZE ];
//StringSource( reinterpret_cast<const char *>(sample), true,
//              new HashFilter(*(new SHA256), new ArraySink(key, AES::MAX_KEYLENGTH)) );
for(int i=0; i< AES::MAX_KEYLENGTH; ++i){
    key[i] = reinterpret_cast<const char *>(decodedKey)[i];
}
memset( iv, 0x00, AES::BLOCKSIZE );
CBC_Mode<AES>::Encryption Encryptor( key, sizeof(key), iv );
StringSource( plain, true, new StreamTransformationFilter( Encryptor,
              new HexEncoder(new StringSink( ciphertext ) ) ) );
return QString::fromStdString(ciphertext);
}