Converting from byte to string and back to byte ends in different results?

[mfunkmann]

Hi there,

I have a really strange conversion-problem here:

--
string _content = new string("some data");

...

System.Text.Encoding _Convert= new System.Text.ASCIIEncoding();
byte[] _encrypted =
_Encrypt.TransformFinalBlock(_Convert.GetBytes(_content), 0,
_Convert.GetByteCount(_content));
_content = _Convert.GetString(_encrypted);
byte[] _t = _Convert.GetBytes(_content);
--

_t differs from _enrypted

I another testprogram I have following code:

--
System.Text.Encoding _Convert = new System.Text.ASCIIEncoding();
byte[] test = { 44, 59, 56, 78, 67, 89, 67, 86 };
text = _Convert.GetString(test);
byte[] _new = _Convert.GetBytes(text);
--

and here _new is equal to test!



Even pasting the code from the testprogram and changing the parameters
accordingly did not work.


I really don't know what to do anymore..

Any ideas?

 

[Jon Skeet [C# MVP]]

I have a really strange conversion-problem here:

It's not really strange at all.

Encryption gives arbitrary binary data. Converting that into ASCII is a
lossy operation, as ASCII only defines values under 128. You shouldn't
treat arbitrary binary data as if it were encoded text. Use something
like Base64 instead (see Convert.ToBase64String and
Convert.FromBase64String).