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Quick and dirty PDF signing in Ruby (using Origami)
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#!/usr/bin/env ruby | |
require "openssl" | |
require "time" | |
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) | |
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) | |
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(signature_annotation) | |
# Sign the PDF with the specified keys | |
pdf.sign(cert, key, | |
method: "adbe.pkcs7.sha1", | |
annotation: signature_annotation, | |
location: "Helsinki", | |
contact: "contact@kiskolabs.com", | |
reason: "Proof of Concept" | |
) | |
# Save the resulting file | |
pdf.save(output_filename) | |
end |
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Sorry, can't help you out there as I haven't needed to touch PDF signing stuff in years and years now…