ProtocolViolationException when writing on response NetworkStream in c

Posted on One min read

I have a piece of code that is returning data with an HttpListener, but I have intermittent error in logs

Bytes to be written to the stream exceed the Content-Length bytes size specified

I wonder where is the error, because the code is simply returning a string with proper encoding and the ContentLength64 property of the Response was set correctly.

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byte[] buffer = Encoding.UTF8.GetBytes(message);
context.Response.ContentEncoding = Encoding.UTF8;
context.Response.ContentLength64 = buffer.Length;
context.Response.OutputStream.Write(buffer, 0, buffer.Length);
context.Response.OutputStream.Flush();

It turns out that some clients sometimes used to do HEAD requests and writing to an OutputStream of an HEAD request generates a ProtocolViolationException , because the client does not expects content to be returned. I’ve simple wrapped the above code with a simple If statement that does not write any content if the HttpMethod of the request is HEAD*(context.Request.HttpMethod != “HEAD”)* and all errors disappeared from log.

Gian Maria.