从其他客户端解密 RSA 时出现 BadPaddingException

Question

我正在编写一个 Android 应用程序，将其 RSA public 密钥广播到网络，并允许其他客户端通过 TCP 连接到它。我有自己的自定义协议和数据包结构，然后我将其加密并发送给客户端（数据包 -> AES -> RSA with client's public key -> client）。

private String encryptPacket(String packet, String pubKey)
{
    PublicKey clientPub = KeyFunctions.stringToKey(pubKey);
    String aesEncryptedData = null;
    byte[] rsaEncryptedData = null;
    String temp = null;

    try
    {
        // AES
        Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
        final SecretKeySpec secretKey = new SecretKeySpec(Constants.KEY.getBytes(), "AES");
        cipher.init(Cipher.ENCRYPT_MODE, secretKey);
        aesEncryptedData = Base64.encodeToString(cipher.doFinal(packet.getBytes()), Base64.NO_PADDING|Base64.NO_WRAP);   //base64 the aes

        // RSA
        Cipher c = Cipher.getInstance("RSA/ECB/PKCS1Padding");
        c.init(Cipher.ENCRYPT_MODE, clientPub);
        rsaEncryptedData = c.doFinal(aesEncryptedData.getBytes());
        temp = Base64.encodeToString(rsaEncryptedData, Base64.NO_PADDING|Base64.NO_WRAP);  // base 64 the rsa
        Log.d("ENC SEND", temp);
    } catch (Exception e)
    {
        e.printStackTrace();
    }
    return temp;
}

public String decryptPacket(String encryptedData, Context context)
{
    // get the keys
    PrivateKey pri = KeyFunctions.getPrivateKey(context);
    byte[] packet = null;
    byte[] decrypted = null;
    String temp = null;

    try
    {
        //RSA
        Cipher c = Cipher.getInstance("RSA/ECB/PKCS1Padding");
        c.init(Cipher.DECRYPT_MODE, pri);
        byte[] rsaTempArray = Base64.decode(encryptedData, Base64.NO_PADDING|Base64.NO_WRAP);
        packet = c.doFinal(rsaTempArray);

        // AES
        Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
        final SecretKeySpec secretKey = new SecretKeySpec(Constants.KEY.getBytes(), "AES");
        cipher.init(Cipher.DECRYPT_MODE, secretKey);
        final String decryptedString = new String(cipher.doFinal(Base64.decode(packet, Base64.NO_PADDING|Base64.NO_WRAP)));
        temp =  decryptedString;
    } catch (Exception e)
    {
        e.printStackTrace();
    }
    Log.d("ENC REC", temp);
    return temp;
}

当客户端向自己发送数据时，此代码有效。但是，将它发送给另一个客户端时它不起作用，给我以下错误：javax.crypto.BadPaddingException: error:0407106B:rsa routines:RSA_padding_check_PKCS1_type_2:block type is not 02

这个异常是在 decryptPacket 调用时引发的，packet = c.doFinal(rsaTempArray);

我试图通过调试验证 public 键的值是否正确，似乎没有任何问题。

更新

这是更新后的代码

private byte[] encryptPacket(Packet packet, String pubKey)
{
    PublicKey clientPub = KeyFunctions.stringToKey(pubKey);
    byte[] aesEncryptedData = null;
    byte[] rsaEncryptedData = null;
    byte[] temp = null;

    Log.d("START", "==========ENCRYPT==========");
    try
    {
        // AES
        Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
        final SecretKeySpec secretKey = new SecretKeySpec(Constants.KEY.getBytes(), "AES");
        cipher.init(Cipher.ENCRYPT_MODE, secretKey);
        byte aesTempArray[] = cipher.doFinal(packet.getBytes());
        Log.d("ENC AES TEMP", new String(aesTempArray, "UTF-8"));
        aesEncryptedData = Base64.encode(aesTempArray, Base64.NO_PADDING | Base64.NO_WRAP);   //base64 the aes
        Log.d("ENC AES ENCR", new String(aesEncryptedData, "UTF-8"));

        // RSA
        Cipher c = Cipher.getInstance("RSA/ECB/PKCS1Padding");
        c.init(Cipher.ENCRYPT_MODE, clientPub);
        rsaEncryptedData = c.doFinal(aesEncryptedData);
        Log.d("ENC RSA ENCR", new String(rsaEncryptedData, "UTF-8"));
        temp = Base64.encode(rsaEncryptedData, Base64.NO_PADDING | Base64.NO_WRAP);  // base 64 the rsa
        Log.d("ENC RSA TEMP", new String(temp, "UTF-8"));
    } catch (Exception e)
    {
        e.printStackTrace();
    }
    return temp;
}

public Packet decryptPacket(byte[] encryptedData, Context context)
{
    // get the keys
    PrivateKey pri = KeyFunctions.getPrivateKey(context);
    Packet p = null;
    byte[] aesDecryptedData = null;
    byte[] rsaDecryptedData = null;


    Log.d("START", "==========DECRYPT==========");
    try
    {
        //RSA
        Log.d("DEC INIT", new String(encryptedData, "UTF-8"));
        Cipher c = Cipher.getInstance("RSA/ECB/PKCS1Padding");
        c.init(Cipher.DECRYPT_MODE, pri);
        byte[] rsaTempArray = Base64.decode(encryptedData, Base64.NO_PADDING | Base64.NO_WRAP);
        Log.d("DEC RSA TEMP", new String(rsaTempArray, "UTF-8"));
        rsaDecryptedData = c.doFinal(rsaTempArray);
        Log.d("DEC RSA ENCR", new String(rsaDecryptedData, "UTF-8"));

        // AES
        Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
        final SecretKeySpec secretKey = new SecretKeySpec(Constants.KEY.getBytes(), "AES");
        cipher.init(Cipher.DECRYPT_MODE, secretKey);
        byte[] aesTempArray = Base64.decode(rsaDecryptedData, Base64.NO_PADDING | Base64.NO_WRAP);
        Log.d("DEC AES TEMP", new String(aesTempArray, "UTF-8"));
        aesDecryptedData = cipher.doFinal(aesTempArray);
        Log.d("DEC AES DEC", new String(aesDecryptedData, "UTF-8"));
        p = new Packet(aesDecryptedData);
    } catch (Exception e)
    {
        e.printStackTrace();
    }
    return p;
}

代码不再使用任何字符串，但仍然出现相同的异常。我现在已经确定接收方已收到与客户端发送的完全相同的数据。当客户端将数据发送到同一设备上的服务器时，该程序可以完美运行，但是当我尝试发送到另一台设备服务器时出现上述异常。两个设备都有自己的私钥/ public 密钥对。每个设备都有彼此的 public 密钥。

Answer 1

Encryption/Decryption 代码很好，我使用错误的 IP 地址来找出 public 密钥。感谢您的帮助！

从其他客户端解密 RSA 时出现 BadPaddingException

BadPaddingException while decrypting RSA from other client

java

encryption

android

cryptography

rsa