const CC = Components.Constructor; const BinaryInputStream = CC( "@mozilla.org/binaryinputstream;1", "nsIBinaryInputStream", "setInputStream" ); const BinaryOutputStream = CC( "@mozilla.org/binaryoutputstream;1", "nsIBinaryOutputStream", "setOutputStream" ); function handleRequest(request, response) { var bodyStream = new BinaryInputStream(request.bodyInputStream); var bodyBytes = []; while ((bodyAvail = bodyStream.available()) > 0) { Array.prototype.push.apply(bodyBytes, bodyStream.readByteArray(bodyAvail)); } var bos = new BinaryOutputStream(response.bodyOutputStream); bos.writeByteArray(bodyBytes, bodyBytes.length); }