Duplicate openssl dgst -md5 -sign myKey.pem something.txt | openssl enc -base64 -A

Demonstrates how to duplicate the creation of an RSA signature produced by this OpenSSL command:

openssl dgst -md5 -sign myKey.pem something.txt | openssl enc -base64 -A

Downloads for Windows/Linux and Install Instructions

require 'chilkat'

pkey = Chilkat::CkPrivateKey.new()

#  Load the private key from an RSA PEM file:
pkey.LoadPemFile("myKey.pem")

#  Get the private key in XML format:
pkeyXml = pkey.getXml()

rsa = Chilkat::CkRsa.new()

#  Any string argument automatically begins the 30-day trial.
success = rsa.UnlockComponent("30-day trial")
if (success != true)
    print rsa.lastErrorText() + "\n";
    exit
end

#  Import the private key into the RSA component:
success = rsa.ImportPrivateKey(pkeyXml)
if (success != true)
    print rsa.lastErrorText() + "\n";
    exit
end

#  OpenSSL uses BigEndian byte ordering:
rsa.put_LittleEndian(false)

#  The resulting signature will be a Base64 string:
rsa.put_EncodingMode("base64")

#  For simplicity, we're not loading
#  the data to be signed from a file.  We are instead simply
#  using a literal string value.
strData = "This is the text to be signed."

#  Hash the input using MD5, and then sign the hash:
#  Other valid hash algorithm choices are "md2" and "sha-1".
base64Sig = rsa.signStringENC(strData,"md5")

print base64Sig + "\n";

print "Success!" + "\n"