Question

I’ve generated a self signed certificate using Adobe X, and exported a pfx file (for my private key) along with a .cer file (for the certificate).

I then try to collect the certificate, along with the key, but for some reason, OpenSSL is giving the error

OpenSSL::X509::CertificateError: not enough data

Here is my code

require 'openssl'

CERTFILE = "test.cer"
RSAKEYFILE = "test.pfx"

# Open certificate files

cert = OpenSSL::X509::Certificate.new(File.read CERTFILE)
key = OpenSSL::PKey::RSA.new(File.read RSAKEYFILE )

My certificate was generated using Adobe X reader, and is a self-signed certificate. It is working fine to sign pdf documents…

What might i do to make this work?

Answer 1

Apparently OpenSSL has some problems reading directly from .cer files, and for the key, we should use only the private_key, and the pfx has both the privatekey and the cert.

So, i installed openSsl locally, and first converted my .cer certificate to .pem with the following command :

C:\OpenSSL-Win32\bin>openssl x509 -inform der -in "c:\mydir\test.cer" -out "C:\mydir\certificate.pem"

and then extracted my privatekey from the pfx file (based on this site) :

C:\OpenSSL-Win32\bin>openssl pkcs12 -in "c:\mydir\test.pfx" -nocerts -out "c:\mydir\test_pk.pem"

just make sure you have your pfx pwd and select a passphrase when you extract the privatekey.

Here is the final code :

require 'openssl'

CERTFILE = "certificate.pem"
RSAKEYFILE = "test_pk.pem"
passphrase = "your chosen passphrase for the private key"
key4pem=File.read RSAKEYFILE

# Open certificate files

cert = OpenSSL::X509::Certificate.new(File.read CERTFILE)
key = OpenSSL::PKey::RSA.new key4pem, passphrase

And voilá :-), we have successfully mapped into memory both our certificate and privatekey, and can put it to uses like the answer here