martintsch · June 5, 2018 10:35 · Mar 2, 2016 · Feb 29, 2016 · Feb 29, 2016
diff --git a/sign-pdf.rb b/sign-pdf.rb
@@ -1,6 +1,7 @@
 #!/usr/bin/env ruby
 
 require "openssl"
+require "time"
 
 begin
   require "origami"
@@ -9,7 +10,6 @@
 end
 include Origami
 
-# openssl req -x509 -newkey rsa:2048 -keyout private_key.pem -out certificate.crt -days 3650 -nodes
 CERT_FILE = "certificate.crt"
 KEY_FILE = "private_key.pem"
 
@@ -28,16 +28,35 @@
   pdf = PDF.read(file)
   page = pdf.get_page(1)
 
+  width = 200.0
+  height = 50.0
+  x = page.MediaBox[2].to_f - width - height
+  y = height
+  size = 8
+
+  now = Time.now
+
+  text_annotation = Annotation::AppearanceStream.new
+  text_annotation.Type = Origami::Name.new("XObject")
+  text_annotation.Resources = Resources.new
+  text_annotation.Resources.ProcSet = [Origami::Name.new("Text")]
+  text_annotation.set_indirect(true)
+  text_annotation.Matrix = [ 1, 0, 0, 1, 0, 0 ]
+  text_annotation.BBox = [ 0, 0, width, height ]
+  text_annotation.write("Signed at #{now.iso8601}", x: size, y: (height/2)-(size/2), size: size)
+
   # Add signature annotation (so it becomes visibles in PDF document)
-  sigannot = Annotation::Widget::Signature.new
-  sigannot.Rect = Rectangle[:llx => 89.0, :lly => 386.0, :urx => 190.0, :ury => 353.0]
+  signature_annotation = Annotation::Widget::Signature.new
+  signature_annotation.Rect = Rectangle[llx: x, lly: y+height, urx: x+width, ury: y]
+  signature_annotation.F = Annotation::Flags::PRINT
+  signature_annotation.set_normal_appearance(text_annotation)
 
-  page.add_annot(sigannot)
+  page.add_annot(signature_annotation)
 
   # Sign the PDF with the specified keys
   pdf.sign(cert, key,
     method: "adbe.pkcs7.sha1",
-    annotation: sigannot,
+    annotation: signature_annotation,
     location: "Helsinki",
     contact: "[email protected]",
     reason: "Proof of Concept"

diff --git a/sign-pdf.rb b/sign-pdf.rb
@@ -9,6 +9,7 @@
 end
 include Origami
 
+# openssl req -x509 -newkey rsa:2048 -keyout private_key.pem -out certificate.crt -days 3650 -nodes
 CERT_FILE = "certificate.crt"
 KEY_FILE = "private_key.pem"
 

diff --git a/sign-pdf.rb b/sign-pdf.rb
@@ -0,0 +1,47 @@
+#!/usr/bin/env ruby
+
+require "openssl"
+
+begin
+  require "origami"
+rescue LoadError
+  abort "origami not installed: gem install origami"
+end
+include Origami
+
+CERT_FILE = "certificate.crt"
+KEY_FILE = "private_key.pem"
+
+input_files = ARGV
+
+if input_files.empty?
+  abort "Usage: sign-pdf input.pdf [...]"
+end
+
+key = OpenSSL::PKey::RSA.new(File.read(KEY_FILE))
+cert = OpenSSL::X509::Certificate.new(File.read(CERT_FILE))
+
+input_files.each do |file|
+  output_filename = file.dup.insert(file.rindex("."), "_signed")
+
+  pdf = PDF.read(file)
+  page = pdf.get_page(1)
+
+  # Add signature annotation (so it becomes visibles in PDF document)
+  sigannot = Annotation::Widget::Signature.new
+  sigannot.Rect = Rectangle[:llx => 89.0, :lly => 386.0, :urx => 190.0, :ury => 353.0]
+
+  page.add_annot(sigannot)
+
+  # Sign the PDF with the specified keys
+  pdf.sign(cert, key,
+    method: "adbe.pkcs7.sha1",
+    annotation: sigannot,
+    location: "Helsinki",
+    contact: "[email protected]",
+    reason: "Proof of Concept"
+  )
+
+  # Save the resulting file
+  pdf.save(output_filename)
+end