Class: CombinePDF::PDFDecrypt

Inherits:
Object
  • Object
show all
Defined in:
lib/combine_pdf/combine_pdf_decrypt.rb

Overview

This is an internal class. you don’t need it.

Instance Method Summary collapse

Constructor Details

#initialize(objects = [], root_dictionary = {}) ⇒ PDFDecrypt

make a new Decrypt object. requires:

objects

an array containing the encrypted objects.

root_dictionary

the root PDF dictionary, containing the Encrypt dictionary.



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# File 'lib/combine_pdf/combine_pdf_decrypt.rb', line 22

def initialize objects=[], root_dictionary = {}
	@objects = objects
	@encryption_dictionary = root_dictionary[:Encrypt]
	raise "Cannot decrypt an encrypted file without an encryption dictionary!" unless @encryption_dictionary
	@root_dictionary = root_dictionary
	@padding_key = [ 0x28, 0xBF, 0x4E, 0x5E, 0x4E, 0x75, 0x8A, 0x41,
					0x64, 0x00, 0x4E, 0x56, 0xFF, 0xFA, 0x01, 0x08,
					0x2E, 0x2E, 0x00, 0xB6, 0xD0, 0x68, 0x3E, 0x80,
					0x2F, 0x0C, 0xA9, 0xFE, 0x64, 0x53, 0x69, 0x7A ]
	@key_crypt_first_iv_store = nil
	@encryption_iv = nil
	PDFOperations.change_references_to_actual_values @objects, @encryption_dictionary
end

Instance Method Details

#decrypt ⇒ Object

call this to start the decryption.



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# File 'lib/combine_pdf/combine_pdf_decrypt.rb', line 37

def decrypt
	raise_encrypted_error @encryption_dictionary unless @encryption_dictionary[:Filter] == :Standard
	@key = set_general_key
	case @encryption_dictionary[:V]
	when 1,2
		warn "trying to decrypt with RC4."
		# raise_encrypted_error
		_perform_decrypt_proc_ @objects, self.method(:decrypt_RC4)
	else
		raise_encrypted_error
	end
	#rebuild stream lengths?
	@objects
end