Remove quotes from MultipartReader boundary (#41308)

Author: aclark09

src/Http/WebUtilities/src/MultipartReader.cs

@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using Microsoft.Extensions.Primitives;
+using Microsoft.Net.Http.Headers;
 
 namespace Microsoft.AspNetCore.WebUtilities;
 
@@ -61,6 +62,7 @@ public MultipartReader(string boundary, Stream stream, int bufferSize)
             throw new ArgumentOutOfRangeException(nameof(bufferSize), bufferSize, "Insufficient buffer space, the buffer must be larger than the boundary: " + boundary);
         }
         _stream = new BufferedReadStream(stream, bufferSize);
+        boundary = HeaderUtilities.RemoveQuotes(new StringSegment(boundary)).ToString();
         _boundary = new MultipartBoundary(boundary, false);
         // This stream will drain any preamble data and remove the first boundary marker.
         // TODO: HeadersLengthLimit can't be modified until after the constructor.

src/Http/WebUtilities/test/MultipartReaderTests.cs

@@ -10,6 +10,7 @@ namespace Microsoft.AspNetCore.WebUtilities;
 public class MultipartReaderTests
 {
     private const string Boundary = "9051914041544843365972754266";
+    private const string BoundaryWithQuotes = @"""9051914041544843365972754266""";
     // Note that CRLF (\r\n) is required. You can't use multi-line C# strings here because the line breaks on Linux are just LF.
     private const string OnePartBody =
 "--9051914041544843365972754266\r\n" +
@@ -377,4 +378,15 @@ public async Task MultipartReader_ReadInvalidUtf8SurrogateHeader_ReplacementChar
 
         Assert.Null(await reader.ReadNextSectionAsync());
     }
+
+    // MultiPartReader should strip any quotes from the boundary passed in instead of throwing an exception
+    [Fact]
+    public async Task MultipartReader_StripQuotesFromBoundary()
+    {
+        var stream = MakeStream(OnePartBody);
+        var reader = new MultipartReader(BoundaryWithQuotes, stream);
+
+        var section = await reader.ReadNextSectionAsync();
+        Assert.NotNull(section);
+    }
 }