Commit a466d97e authored by Jan Provaznik's avatar Jan Provaznik Committed by GitLab Release Tools Bot

Rake task for removing exif from uploads

Adds a rake task which can be used for removing EXIF
data from existing uploads.
parent 6557858f
---
title: Added rake task for removing EXIF data from existing uploads.
merge_request:
author:
type: security
# Uploads Sanitize tasks
## Requirements
You need `exiftool` installed on your system. If you installed GitLab:
- Using the Omnibus package, you're all set.
- From source, make sure `exiftool` is installed:
```sh
# Debian/Ubuntu
sudo apt-get install libimage-exiftool-perl
# RHEL/CentOS
sudo yum install perl-Image-ExifTool
```
## Remove EXIF data from existing uploads
Since 11.9 EXIF data are automatically stripped from JPG or TIFF image uploads.
Because EXIF data may contain sensitive information (e.g. GPS location), you
can remove EXIF data also from existing images which were uploaded before
with the following command:
```bash
sudo RAILS_ENV=production -u git -H bundle exec rake gitlab:uploads:sanitize:remove_exif
```
This command by default runs in dry mode and it doesn't remove EXIF data. It can be used for
checking if (and how many) images should be sanitized.
The rake task accepts following parameters.
Parameter | Type | Description
--------- | ---- | -----------
`start_id` | integer | Only uploads with equal or greater ID will be processed
`stop_id` | integer | Only uploads with equal or smaller ID will be processed
`dry_run` | boolean | Do not remove EXIF data, only check if EXIF data are present or not, default: true
`sleep_time` | float | Pause for number of seconds after processing each image, default: 0.3 seconds
If you have too many uploads, you can speed up sanitization by setting
`sleep_time` to a lower value or by running multiple rake tasks in parallel,
each with a separate range of upload IDs (by setting `start_id` and `stop_id`).
To run the command without dry mode and remove EXIF data from all uploads, you can use:
```bash
sudo RAILS_ENV=production -u git -H bundle exec rake gitlab:uploads:sanitize:remove_exif[,,false,] 2>&1 | tee exif.log
```
To run the command without dry mode on uploads with ID between 100 and 5000 and pause for 0.1 second, you can use:
```bash
sudo RAILS_ENV=production -u git -H bundle exec rake gitlab:uploads:sanitize:remove_exif[100,5000,false,0.1] 2>&1 | tee exif.log
```
Because the output of commands will be probably long, the output is written also into exif.log file.
If sanitization fails for an upload, an error message should be in the output of the rake task (typical reasons may
be that the file is missing in the storage or it's not a valid image). Please
[report](https://gitlab.com/gitlab-org/gitlab-ce/issues/new) any issues at `gitlab.com` and use
prefix 'EXIF' in issue title with the error output and (if possible) the image.
......@@ -15,3 +15,4 @@ comments: false
- [Import](import.md) of git repositories in bulk
- [Rebuild authorized_keys file](http://docs.gitlab.com/ce/raketasks/maintenance.html#rebuild-authorized_keys-file) task for administrators
- [Migrate Uploads](../administration/raketasks/uploads/migrate.md)
- [Sanitize Uploads](../administration/raketasks/uploads/sanitize.md)
# frozen_string_literal: true
module Gitlab
module Sanitizers
class Exif
# these tags are not removed from the image
WHITELISTED_TAGS = %w(
ResolutionUnit
XResolution
YResolution
YCbCrSubSampling
YCbCrPositioning
BitsPerSample
ImageHeight
ImageWidth
ImageSize
Copyright
CopyrightNotice
Orientation
).freeze
# these tags are common in exiftool output, these
# do not contain any sensitive information, but
# we don't need to preserve them when removing
# exif tags
IGNORED_TAGS = %w(
ColorComponents
EncodingProcess
ExifByteOrder
ExifToolVersion
JFIFVersion
Directory
FileAccessDate
FileInodeChangeDate
FileModifyDate
FileName
FilePermissions
FileSize
SourceFile
Megapixels
FileType
FileTypeExtension
MIMEType
).freeze
ALLOWED_TAGS = WHITELISTED_TAGS + IGNORED_TAGS
EXCLUDE_PARAMS = WHITELISTED_TAGS.map { |tag| "-#{tag}" }
attr_reader :logger
def initialize(logger: Rails.logger)
@logger = logger
end
# rubocop: disable CodeReuse/ActiveRecord
def batch_clean(start_id: nil, stop_id: nil, dry_run: true, sleep_time: nil)
relation = Upload.where('lower(path) like ? or lower(path) like ? or lower(path) like ?',
'%.jpg', '%.jpeg', '%.tiff')
logger.info "running in dry run mode, no images will be rewritten" if dry_run
find_params = {
start: start_id.present? ? start_id.to_i : nil,
finish: stop_id.present? ? stop_id.to_i : Upload.last&.id
}
relation.find_each(find_params) do |upload|
clean(upload.build_uploader, dry_run: dry_run)
sleep sleep_time if sleep_time
rescue => err
logger.error "failed to sanitize #{upload_ref(upload)}: #{err.message}"
logger.debug err.backtrace.join("\n ")
end
end
# rubocop: enable CodeReuse/ActiveRecord
def clean(uploader, dry_run: true)
Dir.mktmpdir('gitlab-exif') do |tmpdir|
src_path = fetch_upload_to_file(uploader, tmpdir)
to_remove = extra_tags(src_path)
if to_remove.empty?
logger.info "#{upload_ref(uploader.upload)}: only whitelisted tags present, skipping"
break
end
logger.info "#{upload_ref(uploader.upload)}: found exif tags to remove: #{to_remove}"
break if dry_run
remove_and_store(tmpdir, src_path, uploader)
end
end
def extra_tags(path)
exif_tags(path).keys - ALLOWED_TAGS
end
private
def remove_and_store(tmpdir, src_path, uploader)
exec_remove_exif!(src_path)
logger.info "#{upload_ref(uploader.upload)}: exif removed, storing"
File.open(src_path, 'r') { |f| uploader.store!(f) }
end
def exec_remove_exif!(path)
# IPTC and XMP-iptcExt groups may keep copyright information so
# we always preserve them
cmd = ["exiftool", "-all=", "-tagsFromFile", "@", *EXCLUDE_PARAMS, "--IPTC:all", "--XMP-iptcExt:all", path]
output, status = Gitlab::Popen.popen(cmd)
if status != 0
raise "exiftool return code is #{status}: #{output}"
end
if File.size(path) == 0
raise "size of file is 0"
end
# exiftool creates backup of the original file in filename_original
old_path = "#{path}_original"
if File.size(path) == File.size(old_path)
raise "size of sanitized file is same as original size"
end
end
def fetch_upload_to_file(uploader, dir)
# upload is stored into the file with the original name - this filename
# is used by carrierwave when storing the file back to the storage
filename = File.join(dir, uploader.filename)
File.open(filename, 'w') do |file|
file.binmode
file.write uploader.read
end
filename
end
def upload_ref(upload)
"#{upload.id}:#{upload.path}"
end
def exif_tags(path)
cmd = ["exiftool", "-all", "-j", "-sort", "--IPTC:all", "--XMP-iptcExt:all", path]
output, status = Gitlab::Popen.popen(cmd)
raise "failed to get exif tags: #{output}" if status != 0
JSON.parse(output).first
end
end
end
end
namespace :gitlab do
namespace :uploads do
namespace :sanitize do
desc 'GitLab | Uploads | Remove EXIF from images.'
task :remove_exif, [:start_id, :stop_id, :dry_run, :sleep_time] => :environment do |task, args|
args.with_defaults(dry_run: 'true')
args.with_defaults(sleep_time: 0.3)
logger = Logger.new(STDOUT)
sanitizer = Gitlab::Sanitizers::Exif.new(logger: logger)
sanitizer.batch_clean(start_id: args.start_id, stop_id: args.stop_id,
dry_run: args.dry_run != 'false',
sleep_time: args.sleep_time.to_f)
end
end
end
end
require 'spec_helper'
describe Gitlab::Sanitizers::Exif do
let(:sanitizer) { described_class.new }
describe '#batch_clean' do
context 'with image uploads' do
let!(:uploads) { create_list(:upload, 3, :with_file, :issuable_upload) }
it 'processes all uploads if range ID is not set' do
expect(sanitizer).to receive(:clean).exactly(3).times
sanitizer.batch_clean
end
it 'processes only uploads in the selected range' do
expect(sanitizer).to receive(:clean).once
sanitizer.batch_clean(start_id: uploads[1].id, stop_id: uploads[1].id)
end
it 'pauses if sleep_time is set' do
expect(sanitizer).to receive(:sleep).exactly(3).times.with(1.second)
expect(sanitizer).to receive(:clean).exactly(3).times
sanitizer.batch_clean(sleep_time: 1)
end
end
it 'filters only jpg/tiff images' do
create(:upload, path: 'filename.jpg')
create(:upload, path: 'filename.jpeg')
create(:upload, path: 'filename.JPG')
create(:upload, path: 'filename.tiff')
create(:upload, path: 'filename.TIFF')
create(:upload, path: 'filename.png')
create(:upload, path: 'filename.txt')
expect(sanitizer).to receive(:clean).exactly(5).times
sanitizer.batch_clean
end
end
describe '#clean' do
let(:uploader) { create(:upload, :with_file, :issuable_upload).build_uploader }
context "no dry run" do
it "removes exif from the image" do
uploader.store!(fixture_file_upload('spec/fixtures/rails_sample.jpg'))
original_upload = uploader.upload
expected_args = ["exiftool", "-all=", "-tagsFromFile", "@", *Gitlab::Sanitizers::Exif::EXCLUDE_PARAMS, "--IPTC:all", "--XMP-iptcExt:all", kind_of(String)]
expect(sanitizer).to receive(:extra_tags).and_return(["", 0])
expect(sanitizer).to receive(:exec_remove_exif!).once.and_call_original
expect(uploader).to receive(:store!).and_call_original
expect(Gitlab::Popen).to receive(:popen).with(expected_args) do |args|
File.write("#{args.last}_original", "foo") if args.last.start_with?(Dir.tmpdir)
[expected_args, 0]
end
sanitizer.clean(uploader, dry_run: false)
expect(uploader.upload.id).not_to eq(original_upload.id)
expect(uploader.upload.path).to eq(original_upload.path)
end
it "ignores image without exif" do
expected_args = ["exiftool", "-all", "-j", "-sort", "--IPTC:all", "--XMP-iptcExt:all", kind_of(String)]
expect(Gitlab::Popen).to receive(:popen).with(expected_args).and_return(["[{}]", 0])
expect(sanitizer).not_to receive(:exec_remove_exif!)
expect(uploader).not_to receive(:store!)
sanitizer.clean(uploader, dry_run: false)
end
it "raises an error if the exiftool fails with an error" do
expect(Gitlab::Popen).to receive(:popen).and_return(["error", 1])
expect { sanitizer.clean(uploader, dry_run: false) }.to raise_exception(RuntimeError, "failed to get exif tags: error")
end
end
context "dry run" do
it "doesn't change the image" do
expect(sanitizer).to receive(:extra_tags).and_return({ 'foo' => 'bar' })
expect(sanitizer).not_to receive(:exec_remove_exif!)
expect(uploader).not_to receive(:store!)
sanitizer.clean(uploader, dry_run: true)
end
end
end
describe "#extra_tags" do
it "returns a list of keys for exif file" do
tags = '[{
"DigitalSourceType": "some source",
"ImageHeight": 654
}]'
expect(Gitlab::Popen).to receive(:popen).and_return([tags, 0])
expect(sanitizer.extra_tags('filename')).not_to be_empty
end
it "returns an empty list for file with only whitelisted and ignored tags" do
tags = '[{
"ImageHeight": 654,
"Megapixels": 0.641
}]'
expect(Gitlab::Popen).to receive(:popen).and_return([tags, 0])
expect(sanitizer.extra_tags('some file')).to be_empty
end
end
end
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