Question

I have some Base64 encoded data as a byte array that I’m trying to convert back to it’s original format.

The data is reaches my function encoded twice over. What I want to achieve is something like:

string encoded = "some base 64 string";
byte [] data = System.Convert.FromBase64String(System.Convert.FromBase64String(encoded));

The statement above is wrong of course as I could not figure out which combination of functions to use and ran into unicode issues when I tried. Any pointers would be appreciated.

Answer 1

If I understand your problem right, you’re trying to do this:

• Convert a base64 string into a byte array
• Convert the byte array to an ASCII string
• Convert that string to a byte array with base64

In that case, your statement would look something like this:

byte[] twiceDecoded = Convert.FromBase64String(Encoding.ASCII.GetString(Convert.FromBase64String(encoded)));