introduce raise_on_encrypted option

.travis.yml

@@ -0,0 +1 @@
+language: ruby

Rakefile

@@ -1,2 +1,9 @@
-require "bundler/gem_tasks"
+require 'bundler/gem_tasks'
+require 'rake/testtask'
+
+task default: 'test'
+
+Rake::TestTask.new do |t|
+  t.test_files = FileList['test/**/*_test.rb']
+end
 

combine_pdf.gemspec

@@ -23,4 +23,5 @@ Gem::Specification.new do |spec|
   # spec.add_development_dependency "bundler", ">= 1.7"
   spec.add_development_dependency "rake", ">= 12.3.3"
   spec.add_development_dependency "minitest"
+  spec.add_development_dependency "minitest-around"
 end

lib/combine_pdf/api.rb

@@ -11,6 +11,12 @@ def load(file_name = '', options = {})
     PDF.new(PDFParser.new(IO.read(file_name, mode: 'rb').force_encoding(Encoding::ASCII_8BIT), options))
   end
 
+  def encrypted?(file_name, options = {})
+    parser = PDFParser.new(IO.read(file_name, mode: 'rb').force_encoding(Encoding::ASCII_8BIT), options)
+    parser.parse rescue Zlib::DataError
+    !parser.root_object[:Encrypt].nil?
+  end
+
   # creats a new PDF object.
   #
   # Combine PDF will check to see if `string` is a filename.

lib/combine_pdf/parser.rb

@@ -33,7 +33,7 @@ class PDFParser
     # they are mainly to used to know if the file is (was) encrypted and to get more details.
     attr_reader :info_object, :root_object, :names_object, :forms_object, :outlines_object, :metadata
 
-    attr_reader :allow_optional_content
+    attr_reader :allow_optional_content, :raise_on_encrypted
     # when creating a parser, it is important to set the data (String) we wish to parse.
     #
     # <b>the data is required and it is not possible to set the data at a later stage</b>
@@ -58,6 +58,7 @@ def initialize(string, options = {})
       @version = nil
       @scanner = nil
       @allow_optional_content = options[:allow_optional_content]
+      @raise_on_encrypted = options[:raise_on_encrypted]
     end
 
     # parse the data in the new parser (the data already set through the initialize / new method)
@@ -96,6 +97,7 @@ def parse
       end
 
       if @root_object[:Encrypt]
+        raise EncryptionError if @raise_on_encrypted
         # change_references_to_actual_values @root_object
         warn 'PDF is Encrypted! Attempting to decrypt - not yet fully supported.'
         decryptor = PDFDecrypt.new @parsed, @root_object

lib/combine_pdf/pdf_public.rb

@@ -95,7 +95,14 @@ def initialize(parser = nil)
       @info = {}
       parser ||= PDFParser.new('')
       raise TypeError, "initialization error, expecting CombinePDF::PDFParser or nil, but got #{parser.class.name}" unless parser.is_a? PDFParser
-      @objects = parser.parse
+
+      begin
+        @objects = parser.parse
+      rescue Zlib::DataError => e
+        raise CombinePDF::EncryptionError if parser.root_object[:Encrypt] && parser.raise_on_encrypted
+        raise e
+      end
+
       # remove any existing id's
       remove_old_ids
       # set data from parser

test/combine_pdf/load_test.rb

@@ -0,0 +1,58 @@
+require 'bundler/setup'
+require 'minitest/autorun'
+require 'minitest/around/spec'
+require 'combine_pdf'
+
+describe 'CombinePDF.load' do
+  let(:options) { {} }
+
+  subject { CombinePDF.load "test/fixtures/files/#{file}", options }
+
+  describe 'raise_on_encrypted option' do
+    let(:raise_on_encrypted) { false }
+    let(:file) { 'sample_encrypted_pdf.pdf' }
+    let(:options) { { raise_on_encrypted: raise_on_encrypted } }
+
+    it('has a PDF') { assert_instance_of CombinePDF::PDF, subject }
+
+    describe 'raise_on_encrypted: true' do
+      let(:raise_on_encrypted) { true }
+
+      it('raises an CombinePDF::EncryptionError') do
+        assert_raises(CombinePDF::EncryptionError) { subject }
+      end
+
+      describe 'non-encrypted files' do
+        let(:file) { 'sample_pdf.pdf' }
+
+        it('has a PDF') { assert_instance_of CombinePDF::PDF, subject }
+      end
+
+      describe 'Zlib::DataError' do
+        let(:encrypted?) { false }
+        let(:parser) { Minitest::Mock.new }
+
+        around do |example|
+          parser.expect(:parse, true) { raise Zlib::DataError, 'incorrect data header' }
+          root_object = encrypted? ? { Encrypt: :yes } : { NotEncrypted: :cool }
+          parser.expect(:root_object, root_object)
+          parser.expect(:raise_on_encrypted, raise_on_encrypted)
+          parser.expect(:is_a?, true, [CombinePDF::PDFParser])
+          CombinePDF::PDFParser.stub(:new, parser) { |_| example.call }
+        end
+
+        it('raises Zlib::DataError') do
+          assert_raises(Zlib::DataError) { subject }
+        end
+
+        describe 'encrypted' do
+          let(:encrypted?) { true }
+
+          it('raises an CombinePDF::EncryptionError') do
+            assert_raises(CombinePDF::EncryptionError) { subject }
+          end
+        end
+      end
+    end
+  end
+end

test/combine_pdf/renderer_test.rb

@@ -1,6 +1,4 @@
-require 'bundler/setup'
 require 'minitest/autorun'
-require 'combine_pdf/renderer'
 
 class CombinePDFRendererTest < Minitest::Test