File format issue (plaintext)

Question

I have had an email sent with an attachment which was a zip file. For some reason the email client has not attached it as a seperate file, and simply rendered it as text in the email. There is no other copy of the zip file. I am trying to recover it but do not know if it is possible. The email shows the file like this in text;

>Content-Type: application/x-zip-compressed; name="me.zip";
>
>Content-Disposition: attachment; filename="me.zip"
>
>Content-Transfer-Encoding: base64
>
>
>
>UEsDBBQAAQAIANeV9y5y6d5oG..... etc.

It just continues with random letters for ages. Does anyone know if it is at all possible to recover such a file?

Thanks for any pointers.

Answer 1

I used the code located here to fix this. The online base64 decoders were not working but it worked via this code snippet. Just a copy and paste with no modifications needed;

http://msdn.microsoft.com/en-us/library/system.convert.frombase64string%28v=vs.110%29.aspx

public void DecodeWithString() {
   System.IO.StreamReader inFile;    
   string base64String;

   try {
      char[] base64CharArray;
      inFile = new System.IO.StreamReader(inputFileName,
                              System.Text.Encoding.ASCII);
      base64CharArray = new char[inFile.BaseStream.Length];
      inFile.Read(base64CharArray, 0, (int)inFile.BaseStream.Length);
      base64String = new string(base64CharArray);
   }
   catch (System.Exception exp) {
      // Error creating stream or reading from it.
      System.Console.WriteLine("{0}", exp.Message);
      return;
   }

   // Convert the Base64 UUEncoded input into binary output. 
   byte[] binaryData;
   try {
      binaryData = 
         System.Convert.FromBase64String(base64String);
   }
   catch (System.ArgumentNullException) {
      System.Console.WriteLine("Base 64 string is null.");
      return;
   }
   catch (System.FormatException) {
      System.Console.WriteLine("Base 64 string length is not " +
         "4 or is not an even multiple of 4." );
      return;
   }

   // Write out the decoded data.
   System.IO.FileStream outFile;
   try {
      outFile = new System.IO.FileStream(outputFileName,
                                 System.IO.FileMode.Create,
                                 System.IO.FileAccess.Write);
      outFile.Write(binaryData, 0, binaryData.Length);
      outFile.Close();
   }
   catch (System.Exception exp) {
      // Error creating stream or writing to it.
      System.Console.WriteLine("{0}", exp.Message);
   }
}

Answer 2

It is a base64 encoded file, you can simply decode the base64-encoded characters and output the result to a file (which will be binary data since it's encrypted, so will look even more weird).

The clue is in the Content-Transfer-Encoding header.