1 files changed, 91 insertions, 0 deletions
diff --git a/workhorse/internal/upload/exif.go b/workhorse/internal/upload/exif.go
new file mode 100644
index 00000000000..e77afb24502
--- /dev/null
+++ b/workhorse/internal/upload/exif.go
@@ -0,0 +1,91 @@
+package upload
+
+import (
+	"context"
+	"io"
+	"net/http"
+	"os"
+
+	"gitlab.com/gitlab-org/labkit/log"
+	"golang.org/x/image/tiff"
+
+	"gitlab.com/gitlab-org/gitlab/workhorse/internal/upload/exif"
+)
+
+func handleExifUpload(ctx context.Context, r io.Reader, filename string, imageType exif.FileType) (io.ReadCloser, error) {
+	tmpfile, err := os.CreateTemp("", "exifremove")
+	if err != nil {
+		return nil, err
+	}
+	go func() {
+		<-ctx.Done()
+		tmpfile.Close()
+	}()
+	if err := os.Remove(tmpfile.Name()); err != nil {
+		return nil, err
+	}
+
+	_, err = io.Copy(tmpfile, r)
+	if err != nil {
+		return nil, err
+	}
+
+	if _, err := tmpfile.Seek(0, io.SeekStart); err != nil {
+		return nil, err
+	}
+
+	isValidType := false
+	switch imageType {
+	case exif.TypeJPEG:
+		isValidType = isJPEG(tmpfile)
+	case exif.TypeTIFF:
+		isValidType = isTIFF(tmpfile)
+	}
+
+	if _, err := tmpfile.Seek(0, io.SeekStart); err != nil {
+		return nil, err
+	}
+
+	if !isValidType {
+		log.WithContextFields(ctx, log.Fields{
+			"filename":  filename,
+			"imageType": imageType,
+		}).Info("invalid content type, not running exiftool")
+
+		return tmpfile, nil
+	}
+
+	log.WithContextFields(ctx, log.Fields{
+		"filename": filename,
+	}).Info("running exiftool to remove any metadata")
+
+	cleaner, err := exif.NewCleaner(ctx, tmpfile)
+	if err != nil {
+		return nil, err
+	}
+
+	return cleaner, nil
+}
+
+func isTIFF(r io.Reader) bool {
+	_, err := tiff.DecodeConfig(r)
+	if err == nil {
+		return true
+	}
+
+	if _, unsupported := err.(tiff.UnsupportedError); unsupported {
+		return true
+	}
+
+	return false
+}
+
+func isJPEG(r io.Reader) bool {
+	// Only the first 512 bytes are used to sniff the content type.
+	buf, err := io.ReadAll(io.LimitReader(r, 512))
+	if err != nil {
+		return false
+	}
+
+	return http.DetectContentType(buf) == "image/jpeg"
+}