debian-mirror-gitlab/workhorse/internal/upload/exif.go

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2022-07-23 23:45:48 +05:30
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"
}