I'm working on a Rails application that uses prawn to generate PDF's. Long story short, we want to be able to digitally sign generated PDF's. Im not sure where to start reading up exactly. Just wanted to ask if anybody else has been able to accomplish this before, and if so, what kind of resources I should be using to do it.
Thanks!
Though this question has answer and quite old, I would like to add relevant link for information sake.
MrWater has shared his code to Insert digital signature into existing pdf file.
VERSION 1 - Generate certificate and key file, and insert them directly into the document
require 'openssl'
begin
require 'origami'
rescue LoadError
ORIGAMIDIR = "C:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\origami-1.2.4\lib"
$: << ORIGAMIDIR
require 'origami'
end
include Origami
# Code below is based on documentation available on
# http://www.ruby-doc.org/stdlib-1.9.3/libdoc/openssl/rdoc/OpenSSL.html
key = OpenSSL::PKey::RSA.new 2048
open 'private_key.pem', 'w' do |io| io.write key.to_pem end
open 'public_key.pem', 'w' do |io| io.write key.public_key.to_pem end
cipher = OpenSSL::Cipher::Cipher.new 'AES-128-CBC'
pass_phrase = 'Origami rocks'
key_secure = key.export cipher, pass_phrase
open 'private_key.pem', 'w' do |io|
io.write key_secure
end
#Create the certificate
name = OpenSSL::X509::Name.parse 'CN=nobody/DC=example'
cert = OpenSSL::X509::Certificate.new
cert.version = 2
cert.serial = 0
cert.not_before = Time.now
cert.not_after = Time.now + 3600
cert.public_key = key.public_key
cert.subject = name
OUTPUTFILE = "test.pdf"
contents = ContentStream.new.setFilter(:FlateDecode)
contents.write OUTPUTFILE,
:x => 350, :y => 750, :rendering => Text::Rendering::STROKE, :size => 30
pdf = PDF.read('Sample.pdf')
# Open certificate files
#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 => "Portugal",
:contact => "myemail@email.tt",
:reason => "Proof of Concept"
)
# Save the resulting file
pdf.save(OUTPUTFILE)
VERSION 2 - Use existing certificates to sign a pdf document
require 'openssl'
begin
require 'origami'
rescue LoadError
ORIGAMIDIR = "C:\RailsInstaller\Ruby1.9.3\lib\ruby\gems\1.9.1\gems\origami-1.2.4\lib"
$: << ORIGAMIDIR
require 'origami'
end
include Origami
INPUTFILE = "Sample.pdf"
@inputfile = String.new(INPUTFILE)
OUTPUTFILE = @inputfile.insert(INPUTFILE.rindex("."),"_signed")
CERTFILE = "certificate.pem"
RSAKEYFILE = "private_key.pem"
passphrase = "your passphrase"
key4pem=File.read RSAKEYFILE
key = OpenSSL::PKey::RSA.new key4pem, passphrase
cert = OpenSSL::X509::Certificate.new(File.read CERTFILE)
pdf = PDF.read(INPUTFILE)
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 => "Portugal",
:contact => "myemail@email.tt",
:reason => "Proof of Concept"
)
# Save the resulting file
pdf.save(OUTPUTFILE)
I'd suggest you to take a look at https://github.com/joseicosta/odf-report. It's a gem for generating ODF, but they can easily be converted to PDF, plus it supports templates.
