Remove implementation-dependent information from an error message

The message for CarrierWave::ProcessingError used to include
- the name of the underlying image processor (RMagick, MiniMagick or
  libvips) and
- the original error message produced by it.

The message is used for ActiveRecord validation, and it is often shown for
an end-user. This behavior has some downsides:
- The message may look cryptic and is confusing for end-users. A typical
  end-user has no idea what is RMagick, for example.
- The information the message carries may be valuable for an adversary.
  Especially, the image processor may not be careful enough to mask
  sensitive information in an error message it produces. e.g. MiniMagick
  may include stderr of ImageMagick, which may contain file paths and
  reveal underlying ImageMagick configurations, in an error message.

This change solves the problems by simply removing those information.
You may still retrieve the original error message with
CarrierWave::ProcessingError#cause for debugging or programatic error
handling.

README.md

@@ -1000,8 +1000,7 @@ errors:
     extension_denylist_error: "You are not allowed to upload %{extension} files, prohibited types: %{prohibited_types}"
     content_type_allowlist_error: "You are not allowed to upload %{content_type} files, allowed types: %{allowed_types}"
     content_type_denylist_error: "You are not allowed to upload %{content_type} files"
-    rmagick_processing_error: "Failed to manipulate with rmagick, maybe it is not an image?"
-    mini_magick_processing_error: "Failed to manipulate with MiniMagick, maybe it is not an image? Original Error: %{e}"
+    processing_error: "Failed to manipulate, maybe it is not an image?"
     min_size_error: "File size should be greater than %{min_size}"
     max_size_error: "File size should be less than %{max_size}"
 ```

lib/carrierwave/locale/en.yml

@@ -8,8 +8,6 @@ en:
       extension_denylist_error: "You are not allowed to upload %{extension} files, prohibited types: %{prohibited_types}"
       content_type_allowlist_error: "You are not allowed to upload %{content_type} files, allowed types: %{allowed_types}"
       content_type_denylist_error: "You are not allowed to upload %{content_type} files"
-      rmagick_processing_error: "Failed to manipulate with rmagick, maybe it is not an image?"
-      mini_magick_processing_error: "Failed to manipulate with MiniMagick, maybe it is not an image? Original Error: %{e}"
-      vips_processing_error: "Failed to manipulate with vips, maybe it is not an image? Original Error: %{e}"
+      processing_error: "Failed to manipulate, maybe it is not an image?"
       min_size_error: "File size should be greater than %{min_size}"
       max_size_error: "File size should be less than %{max_size}"

lib/carrierwave/processing/mini_magick.rb

@@ -263,8 +263,8 @@ module CarrierWave
       FileUtils.mv image.path, current_path
 
       image.run_command("identify", current_path)
-    rescue ::MiniMagick::Error, ::MiniMagick::Invalid => e
-      message = I18n.translate(:"errors.messages.mini_magick_processing_error", :e => e)
+    rescue ::MiniMagick::Error, ::MiniMagick::Invalid
+      message = I18n.translate(:"errors.messages.processing_error")
       raise CarrierWave::ProcessingError, message
     ensure
       image.destroy! if image
@@ -309,8 +309,8 @@ module CarrierWave
         file.content_type = Marcel::Magic.by_path(move_to).try(:type)
         file.move_to(move_to, permissions, directory_permissions)
       end
-    rescue ::MiniMagick::Error, ::MiniMagick::Invalid => e
-      message = I18n.translate(:"errors.messages.mini_magick_processing_error", :e => e)
+    rescue ::MiniMagick::Error, ::MiniMagick::Invalid
+      message = I18n.translate(:"errors.messages.processing_error")
       raise CarrierWave::ProcessingError, message
     end
 

lib/carrierwave/processing/rmagick.rb

@@ -370,8 +370,8 @@ module CarrierWave
       end
 
       destroy_image(frames)
-    rescue ::Magick::ImageMagickError => e
-      raise CarrierWave::ProcessingError, I18n.translate(:"errors.messages.rmagick_processing_error", :e => e)
+    rescue ::Magick::ImageMagickError
+      raise CarrierWave::ProcessingError, I18n.translate(:"errors.messages.processing_error")
     end
 
   private

lib/carrierwave/processing/vips.rb

@@ -262,8 +262,8 @@ module CarrierWave
         file.content_type = Marcel::Magic.by_path(move_to).try(:type)
         file.move_to(move_to, permissions, directory_permissions)
       end
-    rescue ::Vips::Error => e
-      message = I18n.translate(:"errors.messages.vips_processing_error", :e => e)
+    rescue ::Vips::Error
+      message = I18n.translate(:"errors.messages.processing_error")
       raise CarrierWave::ProcessingError, message
     end
 

spec/processing/mini_magick_spec.rb

@@ -228,16 +228,16 @@ describe CarrierWave::MiniMagick do
       before { File.open(instance.current_path, 'w') { |f| f.puts "bogus" } }
 
       it "fails to process a non image file" do
-        expect { instance.resize_to_limit(200, 200) }.to raise_exception(CarrierWave::ProcessingError, /^Failed to manipulate with MiniMagick, maybe it is not an image\?/)
+        expect { instance.resize_to_limit(200, 200) }.to raise_exception(CarrierWave::ProcessingError, /^Failed to manipulate, maybe it is not an image\?/)
       end
 
       it "uses I18n" do
         change_locale_and_store_translations(:nl, :errors => {
           :messages => {
-            :mini_magick_processing_error => "Kon bestand niet met MiniMagick bewerken, misschien is het geen beeld bestand?"
+            :processing_error => "Kon bestand niet bewerken, misschien is het geen beeld bestand?"
           }
         }) do
-          expect {instance.resize_to_limit(200, 200)}.to raise_exception(CarrierWave::ProcessingError, /^Kon bestand niet met MiniMagick bewerken, misschien is het geen beeld bestand\?/)
+          expect {instance.resize_to_limit(200, 200)}.to raise_exception(CarrierWave::ProcessingError, /^Kon bestand niet bewerken, misschien is het geen beeld bestand\?/)
         end
       end
 

spec/processing/rmagick_spec.rb

@@ -318,16 +318,16 @@ describe CarrierWave::RMagick, :rmagick => true do
       end
 
       it "fails to process a non image file" do
-        expect {instance.resize_to_limit(200, 200)}.to raise_exception(CarrierWave::ProcessingError, /^Failed to manipulate with rmagick, maybe it is not an image\?/)
+        expect {instance.resize_to_limit(200, 200)}.to raise_exception(CarrierWave::ProcessingError, /^Failed to manipulate, maybe it is not an image\?/)
       end
 
       it "uses I18n" do
         change_locale_and_store_translations(:nl, :errors => {
           :messages => {
-            :rmagick_processing_error => "Kon bestand niet met rmagick bewerken, misschien is het geen beeld bestand?"
+            :processing_error => "Kon bestand niet bewerken, misschien is het geen beeld bestand?"
           }
         }) do
-          expect {instance.resize_to_limit(200, 200)}.to raise_exception(CarrierWave::ProcessingError, /^Kon bestand niet met rmagick bewerken, misschien is het geen beeld bestand\?/)
+          expect {instance.resize_to_limit(200, 200)}.to raise_exception(CarrierWave::ProcessingError, /^Kon bestand niet bewerken, misschien is het geen beeld bestand\?/)
         end
       end
 

spec/processing/vips_spec.rb

@@ -228,16 +228,16 @@ describe CarrierWave::Vips do
       before { File.open(instance.current_path, 'w') { |f| f.puts "bogus" } }
 
       it "fails to process a non image file" do
-        expect { instance.resize_to_limit(200, 200) }.to raise_exception(CarrierWave::ProcessingError, /^Failed to manipulate with vips, maybe it is not an image\?/)
+        expect { instance.resize_to_limit(200, 200) }.to raise_exception(CarrierWave::ProcessingError, /^Failed to manipulate, maybe it is not an image\?/)
       end
 
       it "uses I18n" do
         change_locale_and_store_translations(:nl, :errors => {
           :messages => {
-            :vips_processing_error => "Kon bestand niet met vips bewerken, misschien is het geen beeld bestand?"
+            :processing_error => "Kon bestand niet bewerken, misschien is het geen beeld bestand?"
           }
         }) do
-          expect {instance.resize_to_limit(200, 200)}.to raise_exception(CarrierWave::ProcessingError, /^Kon bestand niet met vips bewerken, misschien is het geen beeld bestand?\?/)
+          expect {instance.resize_to_limit(200, 200)}.to raise_exception(CarrierWave::ProcessingError, /^Kon bestand niet bewerken, misschien is het geen beeld bestand?\?/)
         end
       end