From 4f15f7b34f592936c2c103c0c605b04139313380 Mon Sep 17 00:00:00 2001
From: Jens Kraemer <jk@jkraemer.net>
Date: Thu, 2 Mar 2017 10:47:01 +0800
Subject: [PATCH 2/3] adds a rake task to convert the digests of existing
 attachments to SHA256

---
 app/models/attachment.rb     | 21 +++++++++++++++++++++
 lib/tasks/redmine.rake       |  5 +++++
 test/unit/attachment_test.rb |  9 +++++++++
 3 files changed, 35 insertions(+)

diff --git a/app/models/attachment.rb b/app/models/attachment.rb
index 3bfecfc..51b26b9 100644
--- a/app/models/attachment.rb
+++ b/app/models/attachment.rb
@@ -352,6 +352,27 @@ class Attachment < ActiveRecord::Base
     end
   end
 
+  # Updates attachments' digests to SHA256
+  def self.update_digest_to_sha256
+    Attachment.where("length(digest) < 64").find_in_batches do |group|
+      group.each do |attachment|
+        attachment.update_digest_to_sha256!
+      end
+    end
+  end
+
+  def update_digest_to_sha256!
+    if readable?
+      sha = Digest::SHA256.new
+      File.open(diskfile, 'rb') do |f|
+        while buffer = f.read(8192)
+          sha.update(buffer)
+        end
+      end
+      update_column :digest, sha.hexdigest
+    end
+  end
+
   # Returns true if the extension is allowed regarding allowed/denied
   # extensions defined in application settings, otherwise false
   def self.valid_extension?(extension)
diff --git a/lib/tasks/redmine.rake b/lib/tasks/redmine.rake
index 973e63e..bb7a9cd 100644
--- a/lib/tasks/redmine.rake
+++ b/lib/tasks/redmine.rake
@@ -26,6 +26,11 @@ namespace :redmine do
     task :move_to_subdirectories => :environment do
       Attachment.move_from_root_to_target_directory
     end
+
+    desc 'Updates attachment digests to SHA256'
+    task :update_digest_to_sha256 => :environment do
+      Attachment.update_digest_to_sha256
+    end
   end
 
   namespace :tokens do
diff --git a/test/unit/attachment_test.rb b/test/unit/attachment_test.rb
index a70009d..e1662f6 100644
--- a/test/unit/attachment_test.rb
+++ b/test/unit/attachment_test.rb
@@ -332,6 +332,14 @@ class AttachmentTest < ActiveSupport::TestCase
     assert_equal 'text/plain', attachment.content_type
   end
 
+  test 'should update digest to sha256' do
+    set_fixtures_attachments_directory
+    attachment = Attachment.find 4
+    assert File.readable? attachment.diskfile
+    attachment.update_digest_to_sha256!
+    assert_equal 'c2db49ac68eaebb1703db09411dcd8186b395f4ae8482e449a5d5abff96c7fb2', attachment.digest
+  end
+
   def test_update_attachments
     attachments = Attachment.where(:id => [2, 3]).to_a
 
@@ -430,4 +438,5 @@ class AttachmentTest < ActiveSupport::TestCase
   else
     puts '(ImageMagick convert not available)'
   end
+
 end
-- 
2.1.4