DBEX: make pdf extension evaluation case insensitive (#16250)

* Make pdf extension evaluation case insensitive

* Relocate extension type check

app/models/form_attachment.rb

@@ -13,7 +13,7 @@ class FormAttachment < ApplicationRecord
 
   def set_file_data!(file, file_password = nil)
     attachment_uploader = get_attachment_uploader
-    file = unlock_pdf(file, file_password) if file_password.present?
+    file = unlock_pdf(file, file_password) if File.extname(file).downcase == '.pdf' && file_password.present?
     attachment_uploader.store!(file)
     self.file_data = { filename: attachment_uploader.filename }.to_json
   rescue CarrierWave::IntegrityError => e
@@ -36,15 +36,13 @@ def get_file
   private
 
   def unlock_pdf(file, file_password)
-    return file unless File.extname(file) == '.pdf'
-
     pdftk = PdfForms.new(Settings.binaries.pdftk)
     tmpf = Tempfile.new(['decrypted_form_attachment', '.pdf'])
 
     begin
       pdftk.call_pdftk(file.tempfile.path, 'input_pw', file_password, 'output', tmpf.path)
     rescue PdfForms::PdftkError => e
-      file_regex = %r{/(?:\w+/)*[\w-]+\.pdf\b}
+      file_regex = %r{/(?:\w+/)*[\w-]+\.pdf\b}i
       password_regex = /(input_pw).*?(output)/
       sanitized_message = e.message.gsub(file_regex, '[FILTERED FILENAME]').gsub(password_regex, '\1 [FILTERED] \2')
       log_message_to_sentry(sanitized_message, 'warn')

spec/models/form_attachment_spec.rb

@@ -11,7 +11,7 @@
     end
 
     describe '#unlock_pdf' do
-      let(:file_name) { 'locked_pdf_password_is_test.pdf' }
+      let(:file_name) { 'locked_pdf_password_is_test.Pdf' }
       let(:bad_password) { 'bad_pw' }
 
       context 'when provided password is incorrect' do