Binary encryption

  • Thread starter Thread starter TomB
  • Start date Start date
T

TomB

Anyone know of an example/tutorial for encrypting a binary file?

I'm able to encrypt/decrypt simple text files, but anything more complicated
craps out.

Thanks
TomB
 
I think there is a class for this in the .Net frame work. I haven't used it
but look in MSDN.
 
TomB said:
Anyone know of an example/tutorial for encrypting a binary file?

I'm able to encrypt/decrypt simple text files, but anything more
complicated
craps out.
Click to expand...

It shouldn't matter what the contents are. What encryption method are you
using? Can you post a short, but complete program that shows what your
problem is?
 
Encrypt and Decrypt are my button names.



RijndaelEnhanced is from

http://www.obviex.com/samples/EncryptionWithSalt.aspx

Thanks

TomB



private void Encrypt_Click(object sender, System.EventArgs e)

{

Cursor.Current=Cursors.WaitCursor;

Encrypt.Text="Encrypting...";

Encrypt.Refresh();

string IV;



IV=(Password.Text+"01234567890123456").Substring(0,16);


RijndaelEnhanced re=new RijndaelEnhanced(Password.Text,IV);


StreamReader _sr=new StreamReader(FileName.Text);

byte[] byteArray=re.EncryptToBytes(_sr.ReadToEnd());

string encryptedText=Convert.ToBase64String(byteArray);

//string encryptedText=re.Encrypt(_sr.ReadToEnd());

StreamWriter _sw;

try

{

_sw=new
StreamWriter(EncryptedFileLocation.Text,false,System.Text.Encoding.UTF8);


_sw.Write( encryptedText);

//_sw.Write(Convert.ToBase64String(byteArray));

_sw.Flush();

_sw.Close();

MessageBox.Show("Encrypted File saved as " +
EncryptedFileLocation.Text,"File
Encrypted",MessageBoxButtons.OK,MessageBoxIcon.Information);

}

catch (Exception ex)

{

MessageBox.Show(ex.Message);

}

finally

{

Encrypt.Text="&Encrypt";

Cursor.Current=Cursors.Default;

}

}

private void Decrypt_Click(object sender, System.EventArgs e)

{


try

{

Decrypt.Text="Decrypting...";

Cursor.Current=Cursors.WaitCursor;

string IV;

IV=(Password.Text+"01234567890123456").Substring(0,16);


RijndaelEnhanced re=new RijndaelEnhanced(Password.Text,IV);


StreamReader _sr=new
StreamReader(EncryptedFileLocation.Text,System.Text.Encoding.UTF8);

string encryptedText=_sr.ReadToEnd();

string DecryptedText=re.Decrypt(encryptedText);

StreamWriter _sw=new
StreamWriter(DecryptedFileLocation.Text,false,System.Text.Encoding.UTF8);

_sw.Write(Convert.FromBase64String(DecryptedText));

//_sw.Write(DecryptedText);

_sw.Flush();

_sw.Close();

MessageBox.Show("Decrypted File saved as '" + DecryptedFileLocation.Text +
"'.","File Decrypted",MessageBoxButtons.OK,MessageBoxIcon.Information);

}

catch (Exception ex)

{

// I imagine an exception would occur if the password is incorrect

//MessageBox.Show(ex.Message);

MessageBox.Show("The file '" + EncryptedFileLocation.Text + "' could not be
decrypted. Please ensure you entered the correct password and filename",

"Unable to decrypt file",

MessageBoxButtons.OK,

MessageBoxIcon.Warning );

}

finally

{

Decrypt.Text="Decrypt";

Cursor.Current=Cursors.Default;

}

}
 
TomB said:
Encrypt and Decrypt are my button names.
Click to expand...

<snip>

The problem is that you're treating the binary files as if they're text
files. Don't use a StreamReader - just read straight from the stream.
 
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