security_handler.rb in hexapdf-0.20.3

- old
+ new

@@ -247,10 +247,14 @@
       # Creates a new SecurityHandler for the given document.
       def initialize(document)
         @document = document
         @encrypt_dict_hash = nil
         @encryption_details = {}
+
+        @is_encrypt_dict = document.revisions.each.with_object({}) do |rev, hash|
+          hash[rev.trailer[:Encrypt]] = true
+        end
       end
 
       # Checks if the encryption key computed by this security handler is derived from the
       # document's encryption dictionary.
       def encryption_key_valid?
@@ -260,10 +264,10 @@
       # Decrypts the strings and the possibly attached stream of the given indirect object in
       # place.
       #
       # See: PDF1.7 s7.6.2
       def decrypt(obj)
-        return obj if obj == document.trailer[:Encrypt] || obj.type == :XRef
+        return obj if @is_encrypt_dict[obj] || obj.type == :XRef
 
         key = object_key(obj.oid, obj.gen, string_algorithm)
         each_string_in_object(obj.value) do |str|
           next if str.empty? || (obj.type == :Sig && obj[:Contents].equal?(str))
           str.replace(string_algorithm.decrypt(key, str))