(Ruby) RSA Sign with PKCS8 Encrypted Key

Demonstrates how to load a private key from an encrypted PKCS8 file and create an RSA digital signature (and then verify it).

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

require 'chilkat'

# This example assumes the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

pkey = Chilkat::CkPrivateKey.new()

# Load the private key from an RSA PEM file:
success = pkey.LoadPkcs8EncryptedFile("raul_privateKey.key","a0123456789")

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

rsa = Chilkat::CkRsa.new()

# 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")

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

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

print hexSig + "\n";

# Now verify with the public key.
# This example shows how to use the public key from 
# a digital certificate (.cer file)
cert = Chilkat::CkCert.new()
success = cert.LoadFromFile("raul_publicKey.cer")
if (success != true)
    print cert.lastErrorText() + "\n";
    exit
end

# pubKey is a CkPublicKey
pubKey = cert.ExportPublicKey()

# Get the private key in XML format:
pubKeyXml = pubKey.getXml()

rsa2 = Chilkat::CkRsa.new()
success = rsa2.ImportPublicKey(pubKeyXml)
if (success != true)
    print rsa2.lastErrorText() + "\n";
    exit
end

# Verify the signature against the original data:
rsa2.put_EncodingMode("hex")
success = rsa2.VerifyStringENC(strData,"sha-1",hexSig)
if (success != true)
    print rsa2.lastErrorText() + "\n";
    exit
end

print "Signature verified!" + "\n";

# Verify with incorrect data:
success = rsa2.VerifyStringENC("something else","sha-1",hexSig)
if (success != true)
    print "Signature not verified! (which was expected in this case)" + "\n";
else
    print "Hmmm... that's not right..." + "\n";
end