(Ruby) RSA Sign using Private Key of Certificate Type A3 (smart card / token)

Demonstrates RSA signing data using the private key of a certificate type A3 (smart card, token).

Note: This is a Windows-only example.

Chilkat Ruby Downloads install from rubygems.org gem install chilkat or download... Ruby Library for Windows, MacOS, Linux, Alpine Linux

require 'chilkat'

#  First get the A3 certificate that was installed on the Windows system.
certStore = Chilkat::CkCertStore.new()

thumbprint = "12c1dd8015f3f03f7b1fa619dc24e2493ca8b4b2"

#  This is specific to Windows because it is opening the Windows Current-User certificate store.
bReadOnly = true
success = certStore.OpenCurrentUserStore(bReadOnly)
if (success != true)
    print certStore.lastErrorText() + "\n";
    exit
end

#  Find the certificate with the desired thumbprint
#  (There are many ways to locate a certificate.  This example chooses to find by thumbprint.)
# cert is a CkCert
cert = certStore.FindCertBySha1Thumbprint(thumbprint)
if (certStore.get_LastMethodSuccess() != true)
    print "Failed to find the certificate." + "\n";
    exit
end

print "Found: " + cert.subjectCN() + "\n";

rsa = Chilkat::CkRsa.new()

#  Provide the cert's private key
bUsePrivateKey = true
success = rsa.SetX509Cert(cert,bUsePrivateKey)

if (success != true)
    print rsa.lastErrorText() + "\n";
    exit
end

#  Now we're ready to sign..
dataToSign = Chilkat::CkByteData.new()
sigData = Chilkat::CkByteData.new()

#  Get bytes to be signed..
fac = Chilkat::CkFileAccess.new()
success = fac.ReadEntireFile("in.dat",dataToSign)

success = rsa.SignBytes(dataToSign,"SHA-256",sigData)
if (success != true)
    print rsa.lastErrorText() + "\n";
    exit
end

print "Signature created." + "\n";