Create PKCS1 RSA Signature with PEM Private Key

Demonstrates how to load a private key from a PEM file and create a PKCS1 RSA digital signature.

Downloads for Windows/Linux and Install Instructions

require 'rubygems'
require 'chilkat'

pkey = Chilkat::CkPrivateKey.new()

#  Load the private key from an RSA PEM file:
pkey.LoadPemFile("pvkey2_rsa.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 component unlock failed" + "\n"
    exit
end

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

#  This example will sign a string, and receive the signature
#  in a hex-encoded string.  Therefore, set the encoding mode
#  to "hex":
rsa.put_EncodingMode("hex")

#  If some other non-Chilkat software is going to verify
#  the signature, it is important to match the byte-ordering.
#  The LittleEndian property may be set to true
#  for little-endian byte ordering,
#  or false  for big-endian byte ordering.
#  Microsoft apps typically use little-endian, while
#  OpenSSL and other services (such as Amazon CloudFront)
#  use big-endian.
rsa.put_LittleEndian(false)

strData = "This is the string to be signed."

#  Sign the string using the sha-1 hash algorithm.
#  Other valid choices are "md2", "md5", "sha256",
#  "sha384", and "sha512".
hexSig = rsa.signStringENC(strData,"sha-1")

print hexSig + "\n";

print "Success!" + "\n"