public static async Task <HttpContent> GetContentAsync(Stream stream, HttpRequestContentHeaders headerStruct, CancellationToken ctsToken = default)
{
if (headerStruct.RequestHeaders != null && headerStruct.RequestHeaders.Contains("Transfer-Encoding"))
{
// https://tools.ietf.org/html/rfc7230#section-4
// All transfer-coding names are case-insensitive
if ("chunked".Equals(headerStruct.RequestHeaders.TransferEncoding.Last().Value, StringComparison.OrdinalIgnoreCase))
{
return(await GetDecodedChunkedContentAsync(stream, headerStruct, ctsToken));
}
// https://tools.ietf.org/html/rfc7230#section-3.3.3
// If a Transfer - Encoding header field is present in a response and
// the chunked transfer coding is not the final encoding, the
// message body length is determined by reading the connection until
// it is closed by the server. If a Transfer - Encoding header field
// is present in a request and the chunked transfer coding is not
// the final encoding, the message body length cannot be determined
// reliably; the server MUST respond with the 400(Bad Request)
// status code and then close the connection.
else
{
return(await GetContentTillEndAsync(stream, ctsToken));
}
}
// https://tools.ietf.org/html/rfc7230#section-3.3.3
// 5.If a valid Content - Length header field is present without
// Transfer - Encoding, its decimal value defines the expected message
// body length in octets.If the sender closes the connection or
// the recipient times out before the indicated number of octets are
// received, the recipient MUST consider the message to be
// incomplete and close the connection.
else if (headerStruct.ContentHeaders.Contains("Content-Length"))
{
long?contentLength = headerStruct.ContentHeaders?.ContentLength;
return(await GetContentTillLengthAsync(stream, contentLength, ctsToken));
}
// https://tools.ietf.org/html/rfc7230#section-3.3.3
// 6.If this is a request message and none of the above are true, then
// the message body length is zero (no message body is present).
// 7. Otherwise, this is a response message without a declared message
// body length, so the message body length is determined by the
// number of octets received prior to the server closing the
// connection.
return(GetDummyOrNullContent(headerStruct.ContentHeaders));
}
private static async Task <HttpContent> GetDecodedChunkedContentAsync(Stream stream, HttpRequestContentHeaders requestHeaders, HttpResponseContentHeaders responseHeaders, CancellationToken ctsToken = default)
{
if (responseHeaders == null && requestHeaders == null)
{
throw new ArgumentException("Response and request headers cannot be both null.");
}
if (responseHeaders != null && 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 IEnumerable <string> chunkExtensions);
// 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);
if (await ReadCRLFLineAsync(stream, Encoding.ASCII, ctsToken) != "")
{
throw new FormatException("Chunk does not end with CRLF.");
}
foreach (var b in chunkData)
{
decodedBody.Add(b);
}
length += chunkSize;
firstChunkLine = await ReadCRLFLineAsync(stream, Encoding.ASCII, ctsToken : ctsToken);
ParseFistChunkLine(firstChunkLine, out long cs, out IEnumerable <string> ces);
chunkSize = cs;
chunkExtensions = ces;
}
// 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 = HeaderSection.CreateNew(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(new ByteArrayContent(decodedBody.ToArray()));
}
private static async Task <HttpContent> GetDecodedChunkedContentAsync(Stream stream, HttpRequestContentHeaders headerStruct, CancellationToken ctsToken = default)
{
return(await GetDecodedChunkedContentAsync(stream, headerStruct, null, ctsToken));
}
