Question

I have a Encryption – Decryption scenario as shown below.

//[Clear text ID string as input] — [(ASCII GetByte) + Encoding] — [Encrption as byte array] — [Database column is in VarBinary] — [Pass byte[] as VarBinary parameter to SP for comparison]

//[ID stored as VarBinary in Database] — [Read as byte array] — [(Decrypt as byte array) + Encoding + (ASCII Get String)] — Show as string in the UI

My question is in the decryption scenario. After decryption I get a byte array. I am doing an encoding (IBM037) after that. Is it correct?
Is there something wrong in the flow shown above?

private static byte[] GetEncryptedID(string id)
{
    Interface_Request input = new Interface_Request();
    input.RequestText = Encodeto64(id);
    input.RequestType = Encryption;

    ProgramInterface inputRequest = new ProgramInterface();
    inputRequest.Test_Trial_Request = input;

    using (KTestService operation = new KTestService())
    {
        return ((operation.KTrialOperation(inputRequest)).Test_Trial_Response.ResponseText);
    }
}


private static string GetDecryptedID(byte[] id)
{
    Interface_Request input = new Interface_Request();
    input.RequestText = id;
    input.RequestType = Decryption;

    ProgramInterface request = new ProgramInterface();
    request.Test_Trial_Request = input;

    using (KTestService operationD = new KTestService())
    {
            ProgramInterface1 response = operationD.KI014Operation(request);
            byte[] decryptedValue = response.ICSF_AES_Response.ResponseText;
            Encoding sourceByteFormat = Encoding.GetEncoding("IBM037");
            Encoding destinationByteFormat = Encoding.ASCII;

            //Convert from one byte format to other (IBM to ASCII)
            byte[] ibmEncodedBytes = Encoding.Convert(sourceByteFormat, destinationByteFormat,decryptedValue);
            return System.Text.ASCIIEncoding.ASCII.GetString(ibmEncodedBytes);

        }
    }

    private static byte[] EncodeTo64(string toEncode)
    {
        byte[] dataInBytes = System.Text.ASCIIEncoding.ASCII.GetBytes(toEncode);
        Encoding destinationByteFormat = Encoding.GetEncoding("IBM037");
        Encoding sourceByteFormat = Encoding.ASCII;

        //Convert from one byte format to other (ASCII to IBM)
        byte[] asciiBytes = Encoding.Convert(sourceByteFormat, destinationByteFormat, dataInBytes);
        return asciiBytes;
    }

Answer 1

I found the answer -while decryption process, after decrypting I am converting IBM037 byte to ASCII byte. Thats why there is encoding coming in. I have updated the code in the question also (with more explanatory variables)