Porting TurboPower Blowfish to .Net - blowfish

Question

I have an application that was originally written in Borland C++ and used a Blowfish algorithm implemented in the TurboPower LockBox component .
This application has now been ported to C#. Currently I call a Borland C++ dll that uses this algorithm. However, when running the application on a 64-bit OS, I get errors whenever attempting to use this dll. If I compile the application as 32-bit, everything works, but we want to have this application work as a 64-bit app. As far as I can tell, that means I need a .Net Blowfish algorithm that works like the C++ one.
I found Blowfish.Net and it looks promising. However, when I use the same key and text the encrypted results do not match. I did find out the C++ dll uses the BlowfishECB algorithm. It also converts the result to Base 64, which I have also done.
Any help with this would be appreciated. Here is some test code in C#.
//Convert the key to a byte array. In C++ the key was 16 bytes long
byte[] _key = new byte[16];
Array.Clear(_key, 0, _key.Length);
var pwdBytes = System.Text.Encoding.Default.GetBytes(LicEncryptKey);
int max = Math.Min(16, pwdBytes.Length);
Array.Copy(pwdBytes, _key, max);
//Convert the string to a byte[] and pad it to to the 8 byte block size
var decrypted = System.Text.Encoding.ASCII.GetBytes(originalString);
var blowfish = new BlowfishECB();
blowfish.Initialize(_key, 0, _key.Length);
int arraySize = decrypted.Length;
int diff = arraySize%BlowfishECB.BLOCK_SIZE;
if (diff != 0)
{
arraySize += (BlowfishECB.BLOCK_SIZE - diff);
}
var decryptedBytes = new Byte[arraySize];
Array.Clear(decryptedBytes, 0, decryptedBytes.Length);
Array.Copy(decrypted, decryptedBytes, decrypted.Length);
//Prepare the byte array for the encrypted string
var encryptedBytes = new Byte[decryptedBytes.Length];
Array.Clear(encryptedBytes, 0, encryptedBytes.Length);
blowfish.Encrypt(decryptedBytes, 0, encryptedBytes, 0, decryptedBytes.Length);
//Convert to Base64
string result = Convert.ToBase64String(encryptedBytes);

Answer 1

It won't compatible with your TurboPower LockBox data.
I'd suggest that you provide a utility to do the data migration by decoding using LockBox in C++ (32-bit), outputting to temp files/tables and re-encoding using Blowfish.Net and C# (64-bit).
This data migration is done once before any upgrade to the .NET version, then it's all compatible with it.
Since you're changing the format: you could also change the format and omit the Base64 conversion by storing binary files/BLOBs, other ideas may also be useful like applying multiple encryptions, or replacing Blowfish by something else.