Signing Documents

//.NET Code
public static byte[] GetNewSessionKey()
{
    using (Aes myAes = Aes.Create("AES"))
    {
        myAes.KeySize = 256;
        myAes.GenerateKey();
        return myAes.Key;
    }
}

//Java Code
String JCE_PROVIDER = "BC";
public byte[] GenerateSessionKey() throws NoSuchAlgorithmException, NoSuchProviderException
{
    Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
    KeyGenerator kgen = KeyGenerator.getInstance("AES", JCE_PROVIDER);
    kgen.init(256);
    SecretKey key = kgen.generateKey();
    byte[] symmKey = key.getEncoded();
    return symmKey;
}

//.NET Code
public static string EncryptWithPublicKey(byte[] stringToEncrypt)
{
    X509Certificate2 certificate;
    certificate = new X509Certificate2(AppDomain.CurrentDomain.BaseDirectory + "\\certificate.cer");
    byte[] cipherbytes = Convert.FromBase64String(Convert.ToBase64String(stringToEncrypt));
    RSACryptoServiceProvider rsa = (RSACryptoServiceProvider)certificate.PublicKey.Key;
    byte[] cipher = rsa.Encrypt(cipherbytes, false);
    return Convert.ToBase64String(cipher);
}

//Java Code
public byte[] EncryptUsingPublicKey(byte[] data) throws IOException, GeneralSecurityException, Exception
{
    // encrypt the session key with the public key
    Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
    PublicKey publicKey = null;
    byte[] bytevalue= readBytesFromFile("Give certificate.cer filepath ");
    //String certificatedata = "";
    CertificateFactory certificateFactory = CertificateFactory.getInstance("X509");
    //byte[] bytevalue = Base64.decode(certificatedata);
    InputStream streamvalue = new ByteArrayInputStream(bytevalue);
    java.security.cert.Certificate certificate = certificateFactory.generateCertificate(streamvalue);
    publicKey = certificate.getPublicKey();
    Cipher pkCipher = Cipher.getInstance("RSA/ECB/PKCS1Padding", "BC");
    pkCipher.init(Cipher.ENCRYPT_MODE, publicKey);
    byte[] encSessionKey = pkCipher.doFinal(data);
    // System.out.println("ENC SESSION KEY : "+ encSessionKey.length);
    return encSessionKey;
}

{
    "Name":"",
    "FileType":"PDF",
    "SignatureType":2,
    "SelectPage":"FIRST",
    "SignaturePosition":"Top-Left",
    "AuthToken":"",
    "File":"",
    "PageNumber":null,
    "PreviewRequired":true,
    "PagelevelCoordinates":null,
    "CustomizeCoordinates":null,
    "SUrl":"http://localhost:52322/Success",
    "FUrl":"http://localhost:52322/Error",
    "CUrl":"http://localhost:52322/Cancel",
    "ReferenceNumber":"REFDB100011",
    "Enableuploadsignature":true,
    "Enablefontsignature":true,
    "EnableDrawSignature":true,
    "EnableeSignaturePad":true,
    "IsCompressed":true,
    "IsCosign":true,
    "EnableViewDocumentLink ": true,
    "Storetodb":true,
    "IsGSTN":true,
    "IsGSTN3B":false
}

//.NET Code
public static byte[] EncryptDataAES(byte[] toEncrypt, byte[] key)
{
    IBufferedCipher cipher = CipherUtilities.GetCipher("AES/ECB/PKCS7");
    cipher.Init(true, new KeyParameter(key));
    int outputSize = cipher.GetOutputSize(toEncrypt.Length);
    byte[] tempOP = new byte[outputSize];
    int processLen = cipher.ProcessBytes(toEncrypt, 0, toEncrypt.Length, tempOP, 0);
    int outputLen = cipher.DoFinal(tempOP, processLen);
    byte[] result = new byte[processLen + outputLen];
    System.Array.Copy(tempOP, 0, result, 0, result.Length);
    return result;
}

//Java Code
public byte[] EncryptUsingSessionKey(byte[] skey, byte[] data) throws InvalidCipherTextException
{
    PaddedBufferedBlockCipher cipher = new PaddedBufferedBlockCipher(new AESEngine(), new PKCS7Padding());
    cipher.init(true, new KeyParameter(skey));
    //
    int outputSize = cipher.getOutputSize(data.length);
    byte[] tempOP = new byte[outputSize];
    int processLen = cipher.processBytes(data, 0, data.length, tempOP, 0);
    int outputLen = cipher.doFinal(tempOP, processLen);
    byte[] result = new byte[processLen + outputLen];
    System.arraycopy(tempOP, 0, result, 0, result.length);
    return result;
}

//.NET Code
public static byte[] Generatehash256(string text)
{
    byte[] message = Encoding.UTF8.GetBytes(text);
    SHA256Managed hashString = new SHA256Managed();
    string hex = "";
    var hashValue = hashString.ComputeHash(message);
    return hashValue;
}

//Java Code
public static byte[] Generatehash256(string text)
{
    byte[] message = Encoding.UTF8.GetBytes(text);
    SHA256Managed hashString = new SHA256Managed();
    string hex = "";
    var hashValue = hashString.ComputeHash(message);
    return hashValue;
}

//.NET Code
public string CompressFileLZMA(string InputFileName)
{
    string TransactionID = DateTime.Now.ToString("yyyyMMddHHmmssfff");
    string OutputFileName = System.Web.Configuration.WebConfigurationManager.AppSettings["filepath"] + TransactionID + "_" + Path.GetFileName(InputFileName.Split('.')[0]).ToString();
    Int32 dictionary = 1 << 23;
    Int32 posStateBits = 2;
    Int32 litContextBits = 3; // for normal files
    // UInt32 litContextBits = 0; // for 32-bit data
    Int32 litPosBits = 0;
    // UInt32 litPosBits = 2; // for 32-bit data
    Int32 algorithm = 2;
    Int32 numFastBytes = 128;
    string mf = "bt4";
    bool eos = true;
    bool stdInMode = false;
    SevenZip.Sdk.CoderPropId[] propIDs =  {
        SevenZip.Sdk.CoderPropId.DictionarySize,
        SevenZip.Sdk.CoderPropId.PosStateBits,
        SevenZip.Sdk.CoderPropId.LitContextBits,
        SevenZip.Sdk.CoderPropId.LitPosBits,
        SevenZip.Sdk.CoderPropId.Algorithm,
        SevenZip.Sdk.CoderPropId.NumFastBytes,
        SevenZip.Sdk.CoderPropId.MatchFinder,
        SevenZip.Sdk.CoderPropId.EndMarker
    };
    object[] properties = {
    (Int32)(dictionary),
    (Int32)(posStateBits),
    (Int32)(litContextBits),
    (Int32)(litPosBits),
    (Int32)(algorithm),
    (Int32)(numFastBytes),
    mf, eos
    };
    using (FileStream inStream = new FileStream(InputFileName, FileMode.Open))
    {
        using (FileStream outStream = new FileStream(OutputFileName, FileMode.Create))
            {
                SevenZip.Sdk.Compression.Lzma.Encoder encoder = new SevenZip.Sdk.Compression.Lzma.Encoder();
                encoder.SetCoderProperties(propIDs, properties);
                encoder.WriteCoderProperties(outStream);
                    Int64 fileSize;
                    if (eos || stdInMode)
                        fileSize = -1;
                            else
                            fileSize = inStream.Length;
                                for (int i = 0; i < 8; i++)
                                    outStream.WriteByte((Byte)(fileSize >> (8 * i)));
                                    encoder.Code(inStream, outStream, -1, -1, null);
            }
    }
    return OutputFileName;
 }