Set a boundary on the download response

t2bot · Jul 10, 2024 · f218fb1 · f218fb1
1 parent 823d716
commit f218fb1
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Showing 4 changed files with 32 additions and 5 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -9,6 +9,12 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 
 *Nothing yet.*
 
+## [1.3.6] - July 10, 2024
+
+### Fixed
+
+* Ensure a `boundary` is set on federation downloads, allowing the download to work.
+
 ## [1.3.5] - July 10, 2024
 
 ### Added

diff --git a/api/v1/download.go b/api/v1/download.go
@@ -2,6 +2,7 @@ package v1
 
 import (
 	"bytes"
+	"github.com/t2bot/matrix-media-repo/util/ids"
 	"net/http"
 
 	"github.com/t2bot/matrix-media-repo/api/_apimeta"
@@ -26,23 +27,30 @@ func FederationDownloadMedia(r *http.Request, rctx rcontext.RequestContext, serv
 	r = _routers.ForceSetParam("server", r.Host, r)
 
 	res := r0.DownloadMedia(r, rctx, _apimeta.UserInfo{})
+	boundary, err := ids.NewUniqueId()
+	if err != nil {
+		rctx.Log.Error("Error generating boundary on response: ", err)
+		return _responses.InternalServerError("unable to generate boundary")
+	}
 	if dl, ok := res.(*_responses.DownloadResponse); ok {
 		return &_responses.DownloadResponse{
-			ContentType: "multipart/mixed",
+			ContentType: "multipart/mixed; boundary=" + boundary,
 			Filename:    "",
 			SizeBytes:   0,
 			Data: readers.NewMultipartReader(
+				boundary,
 				&readers.MultipartPart{ContentType: "application/json", Reader: readers.MakeCloser(bytes.NewReader([]byte("{}")))},
 				&readers.MultipartPart{ContentType: dl.ContentType, FileName: dl.Filename, Reader: dl.Data},
 			),
 			TargetDisposition: "attachment",
 		}
 	} else if rd, ok := res.(*_responses.RedirectResponse); ok {
 		return &_responses.DownloadResponse{
-			ContentType: "multipart/mixed",
+			ContentType: "multipart/mixed; boundary=" + boundary,
 			Filename:    "",
 			SizeBytes:   0,
 			Data: readers.NewMultipartReader(
+				boundary,
 				&readers.MultipartPart{ContentType: "application/json", Reader: readers.MakeCloser(bytes.NewReader([]byte("{}")))},
 				&readers.MultipartPart{Location: rd.ToUrl},
 			),

diff --git a/api/v1/thumbnail.go b/api/v1/thumbnail.go
@@ -2,6 +2,7 @@ package v1
 
 import (
 	"bytes"
+	"github.com/t2bot/matrix-media-repo/util/ids"
 	"net/http"
 
 	"github.com/t2bot/matrix-media-repo/api/_apimeta"
@@ -26,23 +27,30 @@ func FederationThumbnailMedia(r *http.Request, rctx rcontext.RequestContext, ser
 	r = _routers.ForceSetParam("server", r.Host, r)
 
 	res := r0.ThumbnailMedia(r, rctx, _apimeta.UserInfo{})
+	boundary, err := ids.NewUniqueId()
+	if err != nil {
+		rctx.Log.Error("Error generating boundary on response: ", err)
+		return _responses.InternalServerError("unable to generate boundary")
+	}
 	if dl, ok := res.(*_responses.DownloadResponse); ok {
 		return &_responses.DownloadResponse{
-			ContentType: "multipart/mixed",
+			ContentType: "multipart/mixed; boundary=" + boundary,
 			Filename:    "",
 			SizeBytes:   0,
 			Data: readers.NewMultipartReader(
+				boundary,
 				&readers.MultipartPart{ContentType: "application/json", Reader: readers.MakeCloser(bytes.NewReader([]byte("{}")))},
 				&readers.MultipartPart{ContentType: dl.ContentType, FileName: dl.Filename, Reader: dl.Data},
 			),
 			TargetDisposition: "attachment",
 		}
 	} else if rd, ok := res.(*_responses.RedirectResponse); ok {
 		return &_responses.DownloadResponse{
-			ContentType: "multipart/mixed",
+			ContentType: "multipart/mixed; boundary=" + boundary,
 			Filename:    "",
 			SizeBytes:   0,
 			Data: readers.NewMultipartReader(
+				boundary,
 				&readers.MultipartPart{ContentType: "application/json", Reader: readers.MakeCloser(bytes.NewReader([]byte("{}")))},
 				&readers.MultipartPart{Location: rd.ToUrl},
 			),

diff --git a/util/readers/multipart_reader.go b/util/readers/multipart_reader.go
@@ -17,10 +17,15 @@ type MultipartPart struct {
 	Reader      io.ReadCloser
 }
 
-func NewMultipartReader(parts ...*MultipartPart) io.ReadCloser {
+func NewMultipartReader(boundary string, parts ...*MultipartPart) io.ReadCloser {
 	r, w := io.Pipe()
 	go func() {
 		mpw := multipart.NewWriter(w)
+		err := mpw.SetBoundary(boundary)
+		if err != nil {
+			// We don't have a good error route, and don't expect this to fail anyways.
+			panic(err)
+		}
 
 		for _, part := range parts {
 			headers := textproto.MIMEHeader{}