public static HeaderSection CreateNew(HttpHeaders headers)
{
var hs = new HeaderSection();
foreach (var header in headers)
{
hs.Fields.Add(new HeaderField(header.Key, string.Join(",", header.Value)));
}
// -- Start [SECTION] Crazy VS2017/.NET Core 1.1 bug ---
// The following if branch is needed as is to avoid the craziest VS2017/.NET Core 1.1 bug I have ever seen!
// If this section is not added the Content-Length header will not be set unless...
// - I put a break point at the start of the function
// - And I explicitly expand the "headers" variable
if (headers is HttpContentHeaders)
{
if (((HttpContentHeaders)headers).ContentLength != null)
{
if (hs.Fields.All(x => x.Name != "Content-Length"))
{
hs.Fields.Add(new HeaderField("Content-Length", ((HttpContentHeaders)headers).ContentLength.ToString()));
}
}
}
// -- End [SECTION] Crazy VS2017/.NET Core 1.1 bug ---
return(hs);
}
public static HeaderSection CreateNew(string headersString)
{
headersString = HeaderField.CorrectObsFolding(headersString);
var hs = new HeaderSection();
if (headersString.EndsWith(CRLF + CRLF))
{
headersString = headersString.TrimEnd(CRLF, StringComparison.Ordinal);
}
using (var reader = new StringReader(headersString))
{
while (true)
{
var field = reader.ReadLine(strictCRLF: true);
if (field is null)
{
break;
}
hs.Fields.Add(HeaderField.CreateNew(field));
}
ValidateAndCorrectHeaders(hs);
return(hs);
}
}
public static async Task <HeaderSection> CreateNewAsync(string headersString)
{
headersString = HeaderField.CorrectObsFolding(headersString);
var hs = new HeaderSection();
if (headersString.EndsWith(CRLF + CRLF))
{
headersString = headersString.TrimEnd(CRLF, StringComparison.Ordinal);
}
using var reader = new StringReader(headersString);
while (true)
{
var field = reader.ReadLine(strictCRLF: true);
if (field is null)
{
break;
}
hs.Fields.Add(await HeaderField.CreateNewAsync(field).ConfigureAwait(false));
}
ValidateAndCorrectHeaders(hs);
return(hs);
}
private static void ValidateAndCorrectHeaders(HeaderSection hs)
{
// https://tools.ietf.org/html/rfc7230#section-5.4
// Since the Host field - value is critical information for handling a
// request, a user agent SHOULD generate Host as the first header field
// following the request - line.
HeaderField hostToCorrect = null;
foreach (var f in hs.Fields)
{
// if we find host
if (f.Name == "Host")
{
// if host is not first
if (hs.Fields.First().Name != "Host")
{
// then correct host
hostToCorrect = f;
break;
}
}
}
if (hostToCorrect != null)
{
hs.Fields.Remove(hostToCorrect);
hs.Fields.Insert(0, hostToCorrect);
}
// https://tools.ietf.org/html/rfc7230#section-3.3.2
// If a message is received that has multiple Content-Length header
// fields with field-values consisting of the same decimal value, or a
// single Content-Length header field with a field value containing a
// list of identical decimal values(e.g., "Content-Length: 42, 42"),
// indicating that duplicate Content-Length header fields have been
// generated or combined by an upstream message processor, then the
// recipient MUST either reject the message as invalid or replace the
// duplicated field - values with a single valid Content - Length field
// containing that decimal value prior to determining the message body
// length or forwarding the message.
var allParts = new HashSet <string>();
foreach (var field in hs.Fields)
{
if (field.Name == "Content-Length")
{
var parts = field.Value.Trim().Split(',');
foreach (var part in parts)
{
allParts.Add(part.Trim());
}
}
}
if (allParts.Count > 0) // then has Content-Length field
{
if (allParts.Count > 1)
{
throw new InvalidDataException("Invalid Content-Length.");
}
hs.Fields.RemoveAll(x => x.Name == "Content-Length");
hs.Fields.Add(new HeaderField("Content-Length", allParts.First()));
}
}
