private void Append(ref KeyValueAccumulator accumulator) { if (ReadSucceded()) { accumulator.Append(_currentKey, _currentValue); if (accumulator.ValueCount > ValueCountLimit) { throw new InvalidDataException($"Form value count limit {ValueCountLimit} exceeded."); } } }
private async Task<IFormCollection> InnerReadFormAsync(CancellationToken cancellationToken) { if (!HasFormContentType) { throw new InvalidOperationException("Incorrect Content-Type: " + _request.ContentType); } cancellationToken.ThrowIfCancellationRequested(); if (_options.BufferBody) { _request.EnableRewind(_options.MemoryBufferThreshold, _options.BufferBodyLengthLimit); } FormCollection formFields = null; FormFileCollection files = null; // Some of these code paths use StreamReader which does not support cancellation tokens. using (cancellationToken.Register((state) => ((HttpContext)state).Abort(), _request.HttpContext)) { var contentType = ContentType; // Check the content-type if (HasApplicationFormContentType(contentType)) { var encoding = FilterEncoding(contentType.Encoding); using (var formReader = new FormReader(_request.Body, encoding) { ValueCountLimit = _options.ValueCountLimit, KeyLengthLimit = _options.KeyLengthLimit, ValueLengthLimit = _options.ValueLengthLimit, }) { formFields = new FormCollection(await formReader.ReadFormAsync(cancellationToken)); } } else if (HasMultipartFormContentType(contentType)) { var formAccumulator = new KeyValueAccumulator(); var boundary = GetBoundary(contentType, _options.MultipartBoundaryLengthLimit); var multipartReader = new MultipartReader(boundary, _request.Body) { HeadersCountLimit = _options.MultipartHeadersCountLimit, HeadersLengthLimit = _options.MultipartHeadersLengthLimit, BodyLengthLimit = _options.MultipartBodyLengthLimit, }; var section = await multipartReader.ReadNextSectionAsync(cancellationToken); while (section != null) { ContentDispositionHeaderValue contentDisposition; ContentDispositionHeaderValue.TryParse(section.ContentDisposition, out contentDisposition); if (HasFileContentDisposition(contentDisposition)) { // Enable buffering for the file if not already done for the full body section.EnableRewind(_request.HttpContext.Response.RegisterForDispose, _options.MemoryBufferThreshold, _options.MultipartBodyLengthLimit); // Find the end await section.Body.DrainAsync(cancellationToken); var name = HeaderUtilities.RemoveQuotes(contentDisposition.Name) ?? string.Empty; var fileName = HeaderUtilities.RemoveQuotes(contentDisposition.FileName) ?? string.Empty; FormFile file; if (section.BaseStreamOffset.HasValue) { // Relative reference to buffered request body file = new FormFile(_request.Body, section.BaseStreamOffset.Value, section.Body.Length, name, fileName); } else { // Individually buffered file body file = new FormFile(section.Body, 0, section.Body.Length, name, fileName); } file.Headers = new HeaderDictionary(section.Headers); if (files == null) { files = new FormFileCollection(); } if (files.Count >= _options.ValueCountLimit) { throw new InvalidDataException($"Form value count limit {_options.ValueCountLimit} exceeded."); } files.Add(file); } else if (HasFormDataContentDisposition(contentDisposition)) { // Content-Disposition: form-data; name="key" // // value // Do not limit the key name length here because the mulipart headers length limit is already in effect. var key = HeaderUtilities.RemoveQuotes(contentDisposition.Name); MediaTypeHeaderValue mediaType; MediaTypeHeaderValue.TryParse(section.ContentType, out mediaType); var encoding = FilterEncoding(mediaType?.Encoding); using (var reader = new StreamReader(section.Body, encoding, detectEncodingFromByteOrderMarks: true, bufferSize: 1024, leaveOpen: true)) { // The value length limit is enforced by MultipartBodyLengthLimit var value = await reader.ReadToEndAsync(); formAccumulator.Append(key, value); if (formAccumulator.ValueCount > _options.ValueCountLimit) { throw new InvalidDataException($"Form value count limit {_options.ValueCountLimit} exceeded."); } } } else { System.Diagnostics.Debug.Assert(false, "Unrecognized content-disposition for this section: " + section.ContentDisposition); } section = await multipartReader.ReadNextSectionAsync(cancellationToken); } if (formAccumulator.HasValues) { formFields = new FormCollection(formAccumulator.GetResults(), files); } } } // Rewind so later readers don't have to. if (_request.Body.CanSeek) { _request.Body.Seek(0, SeekOrigin.Begin); } if (formFields != null) { Form = formFields; } else if (files != null) { Form = new FormCollection(null, files); } else { Form = FormCollection.Empty; } return Form; }