public static async Task <HttpResponseMessage> CreateNewAsync(Stream responseStream, HttpMethod requestMethod)
{
// https://tools.ietf.org/html/rfc7230#section-3
// The normal procedure for parsing an HTTP message is to read the
// start - line into a structure, read each header field into a hash table
// by field name until the empty line, and then use the parsed data to
// determine if a message body is expected.If a message body has been
// indicated, then it is read as a stream until an amount of octets
// equal to the message body length is read or the connection is closed.
// https://tools.ietf.org/html/rfc7230#section-3
// All HTTP/ 1.1 messages consist of a start - line followed by a sequence
// of octets in a format similar to the Internet Message Format
// [RFC5322]: zero or more header fields(collectively referred to as
// the "headers" or the "header section"), an empty line indicating the
// end of the header section, and an optional message body.
// HTTP - message = start - line
// * (header - field CRLF )
// CRLF
// [message - body]
string startLine = await HttpMessageHelper.ReadStartLineAsync(responseStream).ConfigureAwait(false);
var statusLine = StatusLine.Parse(startLine);
var response = new HttpResponseMessage(statusLine.StatusCode);
string headers = await HttpMessageHelper.ReadHeadersAsync(responseStream).ConfigureAwait(false);
var headerSection = await HeaderSection.CreateNewAsync(headers);
var headerStruct = headerSection.ToHttpResponseHeaders();
HttpMessageHelper.AssertValidHeaders(headerStruct.ResponseHeaders, headerStruct.ContentHeaders);
byte[] contentBytes = await HttpMessageHelper.GetContentBytesAsync(responseStream, headerStruct, requestMethod, statusLine).ConfigureAwait(false);
contentBytes = HttpMessageHelper.HandleGzipCompression(headerStruct.ContentHeaders, contentBytes);
response.Content = contentBytes is null ? null : new ByteArrayContent(contentBytes);
HttpMessageHelper.CopyHeaders(headerStruct.ResponseHeaders, response.Headers);
if (response.Content != null)
{
HttpMessageHelper.CopyHeaders(headerStruct.ContentHeaders, response.Content.Headers);
}
return(response);
}
private static async Task <byte[]> GetDecodedChunkedContentBytesAsync(Stream stream, HttpRequestContentHeaders requestHeaders, HttpResponseContentHeaders responseHeaders, CancellationToken ctsToken = default)
{
if (responseHeaders is null)
{
if (requestHeaders is null)
{
throw new ArgumentException("Response and request headers cannot be both null.");
}
}
else
{
if (requestHeaders != null)
{
throw new ArgumentException("Either response or request headers has to be null.");
}
}
// https://tools.ietf.org/html/rfc7230#section-4.1.3
// 4.1.3.Decoding Chunked
// A process for decoding the chunked transfer coding can be represented
// in pseudo - code as:
// length := 0
// read chunk - size, chunk - ext(if any), and CRLF
// while (chunk - size > 0)
// {
// read chunk-data and CRLF
// append chunk-data to decoded-body
// length:= length + chunk - size
// read chunk-size, chunk - ext(if any), and CRLF
// }
// read trailer field
// while (trailer field is not empty) {
// if (trailer field is allowed to be sent in a trailer) {
// append trailer field to existing header fields
// }
// read trailer-field
// }
// Content - Length := length
// Remove "chunked" from Transfer-Encoding
// Remove Trailer from existing header fields
long length = 0;
var firstChunkLine = await ReadCRLFLineAsync(stream, Encoding.ASCII, ctsToken : ctsToken);
ParseFistChunkLine(firstChunkLine, out long chunkSize, out _);
// We will not do anything with the chunk extensions, because:
// https://tools.ietf.org/html/rfc7230#section-4.1.1
// A recipient MUST ignore unrecognized chunk extensions.
var decodedBody = new List <byte>();
// https://tools.ietf.org/html/rfc7230#section-4.1
// The chunked transfer coding is complete
// when a chunk with a chunk-size of zero is received, possibly followed
// by a trailer, and finally terminated by an empty line.
while (chunkSize > 0)
{
var chunkData = await ReadBytesTillLengthAsync(stream, chunkSize, ctsToken);
string crlfLine = await ReadCRLFLineAsync(stream, Encoding.ASCII, ctsToken);
if (crlfLine.Length != 0)
{
throw new FormatException("Chunk does not end with CRLF.");
}
decodedBody.AddRange(chunkData);
length += chunkSize;
firstChunkLine = await ReadCRLFLineAsync(stream, Encoding.ASCII, ctsToken : ctsToken);
ParseFistChunkLine(firstChunkLine, out long cs, out _);
chunkSize = cs;
}
// https://tools.ietf.org/html/rfc7230#section-4.1.2
// A trailer allows the sender to include additional fields at the end
// of a chunked message in order to supply metadata that might be
// dynamically generated while the message body is sent
string trailerHeaders = await ReadHeadersAsync(stream, ctsToken);
var trailerHeaderSection = await HeaderSection.CreateNewAsync(trailerHeaders);
RemoveInvalidTrailers(trailerHeaderSection);
if (responseHeaders != null)
{
var trailerHeaderStruct = trailerHeaderSection.ToHttpResponseHeaders();
AssertValidHeaders(trailerHeaderStruct.ResponseHeaders, trailerHeaderStruct.ContentHeaders);
// https://tools.ietf.org/html/rfc7230#section-4.1.2
// When a chunked message containing a non-empty trailer is received,
// the recipient MAY process the fields(aside from those forbidden
// above) as if they were appended to the message's header section.
CopyHeaders(trailerHeaderStruct.ResponseHeaders, responseHeaders.ResponseHeaders);
responseHeaders.ResponseHeaders.Remove("Transfer-Encoding");
responseHeaders.ContentHeaders.TryAddWithoutValidation("Content-Length", length.ToString());
responseHeaders.ResponseHeaders.Remove("Trailer");
}
if (requestHeaders != null)
{
var trailerHeaderStruct = trailerHeaderSection.ToHttpRequestHeaders();
AssertValidHeaders(trailerHeaderStruct.RequestHeaders, trailerHeaderStruct.ContentHeaders);
// https://tools.ietf.org/html/rfc7230#section-4.1.2
// When a chunked message containing a non-empty trailer is received,
// the recipient MAY process the fields(aside from those forbidden
// above) as if they were appended to the message's header section.
CopyHeaders(trailerHeaderStruct.RequestHeaders, requestHeaders.RequestHeaders);
requestHeaders.RequestHeaders.Remove("Transfer-Encoding");
requestHeaders.ContentHeaders.TryAddWithoutValidation("Content-Length", length.ToString());
requestHeaders.RequestHeaders.Remove("Trailer");
}
return(decodedBody.ToArray());
}