I received the contents of a text file returned in binary values:
Byte[] buf = new Byte[size];
stream = File.InputStream;
stream.Read(buf, 0, size);
As an alternative to reading a data from a stream to a byte array, you could let the framework handle everything and just use a StreamReader set up with an ASCII encoding to read in the string. That way you don't need to worry about getting the appropriate buffer size or larger data sizes.
using (var reader = new StreamReader(stream, Encoding.ASCII))
{
string theString = reader.ReadToEnd();
// do something with theString
}