使用RSA / ECB / PKCS1Padding进行.Net加密和Java解密

Question

we have existing encryption code in java and which is working absolutely fine.I am trying to create same encryption method in .net which is failing java decryption method saying bad padding exception. See the code details below: Working Java Code: Encryption:

private static byte[] doThis(String message) {
    byte[] messageCrypte = null;
       try {
        // Certificate Input Stream
        // LA SSL Certificate to be passed.
        InputStream inStream = new FileInputStream(certificate);

        // X509Certificate created
        CertificateFactory cf = CertificateFactory.getInstance("X.509");
        X509Certificate cert = (X509Certificate) cf.generateCertificate(inStream);
        inStream.close();

        // Getting Public key using Certficate
        PublicKey rsaPublicKey = (PublicKey) cert.getPublicKey();

        Cipher encryptCipher = Cipher.getInstance("RSA/ECB/PKCS1Padding", "SunJCE");
        encryptCipher.init(Cipher.ENCRYPT_MODE, rsaPublicKey);

        byte[] messageACrypter = message.getBytes();
        // Encrypted String
        messageCrypte = encryptCipher.doFinal(messageACrypter);
       } catch (Exception e) {
        // TODO: Exception Handling
        e.printStackTrace();
       }
    return messageCrypte;
}

Equivalent c# .Net code I am trying to use but I am getting bad padding exception form java decryption code.

    static byte[] doThis(string message)
    {
        X509Certificate cert = new X509Certificate(@"C:\Data\abc-rsa-public-key-certificate.cer");
        byte[] aa = cert.GetPublicKey();

        RSACryptoServiceProvider RSA = new RSACryptoServiceProvider();
        RSAParameters RSAKeyInfo = new RSAParameters();
        byte[] Exponent = { 1, 0, 1 };

        RSAKeyInfo = RSA.ExportParameters(false);
        //Set RSAKeyInfo to the public key values. 
        RSAKeyInfo.Modulus = aa;
        //RSAKeyInfo.Exponent = Exponent;
        RSA.ImportParameters(RSAKeyInfo);
        byte[] bb = RSA.Encrypt(GetBytes(message), false);
        return bb;
    }

Java code for decryption

private String getDecryptedString(byte[] credentials, PrivateKey secretKey) throws NoSuchAlgorithmException,
            NoSuchProviderException, NoSuchPaddingException, InvalidKeyException, IllegalBlockSizeException,
            BadPaddingException {
        String decryptedString;
        Cipher decryptCipher = Cipher.getInstance("RSA/ECB/PKCS1Padding", "SunJCE");
        decryptCipher.init(Cipher.DECRYPT_MODE, secretKey);
        byte[] messageDecrypte = decryptCipher.doFinal(credentials);
        decryptedString = new String(messageDecrypte);
        return decryptedString;
    }

Answer 1

Here is the .net code:

public static string EncrypIt(string inputString, X509Certificate2 cert)
{
    RSACryptoServiceProvider rsaservice = (RSACryptoServiceProvider)cert.PublicKey.Key;
    byte[] plaintext = Encoding.UTF8.GetBytes(inputString);
    byte[] ciphertext = rsaservice.Encrypt(plaintext, false);
    string cipherresult = Convert.ToBase64String(ciphertext);
    return cipherresult;                 
}