(Ruby) RSA Hash Binary Data and Sign (and Verify)

Demonstrates how to sign the hash of binary data. Also demonstrates how to verify the RSA signature.

Note: This example uses methods introduced in Chilkat v9.5.0.77.

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

require 'chilkat'

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

# Load an RSA private key for signing.
privKey = Chilkat::CkPrivateKey.new()
success = privKey.LoadEncryptedPemFile("qa_data/pem/rsa_passwd.pem","passwd")
if (success != true)
    print privKey.lastErrorText() + "\n";
    exit
end

rsa = Chilkat::CkRsa.new()
rsa.ImportPrivateKeyObj(privKey)

# We have some binary data (in hex) to sign
originalData = "0102030405060708090A"
bdData = Chilkat::CkBinData.new()
bdData.AppendEncoded(originalData,"hex")

# Hash (SHA-256) and sign the hash:
bdSignature = Chilkat::CkBinData.new()
success = rsa.SignBd(bdData,"sha256",bdSignature)
if (success != true)
    print rsa.lastErrorText() + "\n";
    exit
end

# Show the RSA signature in base64
print bdSignature.getEncoded("base64") + "\n";

# ------------------------------------------
# Get the public key from the private key
# pubKey is a CkPublicKey
pubKey = privKey.GetPublicKey()

# Verify the signature..
rsa2 = Chilkat::CkRsa.new()
rsa2.ImportPublicKeyObj(pubKey)

bVerified = rsa2.VerifyBd(bdData,"sha256",bdSignature)
print "signature verified: " + bVerified.to_s() + "\n";