From: Andy Stewart <ruth_andy@...>
Date: 2006-08-11T21:07:30+09:00
Subject: Cryptographic Signatures: Ruby versus OpenSSL

Hello Everyone,

I am having problems matching up a signature created with openssl on  
the command line with a signature created in Ruby.

The signature I am trying to get is an RSA encryption with my 1024  
bit private key of a SHA-1 hash of data.

This is what I did on the command line:

$ openssl genrsa -out private.pem 1024
$ echo -n "Some text to sign" \
     | openssl dgst -sha1 -binary \
     | openssl rsautl -sign -inkey private.pem \
     | openssl enc -base64

This is what I did in Ruby:

require 'base64'
require 'openssl'
include OpenSSL
include PKey
include Digest

private_key = RSA.new(File.open("/Users/andy/tmp/private.pem").read)
signature  = private_key.sign(OpenSSL::Digest::SHA1.new, "Some text  
to sign")
puts Base64.encode64(signature)

Unfortunately the base64-encoded signatures produced by each method  
don't match.

I have spent quite a lot of time with Google and the RubyPKI source  
-- but I am new to Ruby and have exhausted all the avenues I can  
think of.

Any help would be much appreciated.

Thanks and regards,
Andy Stewart