Ruby

ECDSA Sign and Verify Data using Different Hash Algorithms

See more ECC Examples

Demonstrates how to create ECDSA signatures on data using different hash algorithms.

Note: This example requires Chilkat v9.5.0.85 or greater because the SignBd and VerifyBd methods were added in v9.5.0.85.

Ruby

require 'chilkat'

success = false

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

# First load an ECDSA private key to be used for signing.
privKey = Chilkat::CkPrivateKey.new()
success = privKey.LoadEncryptedPemFile("qa_data/ecc/secp256r1-key-pkcs8-secret.pem","secret")
if (success == false)
    print privKey.lastErrorText() + "\n";
    exit
end

# Load some data to be signed.
bd = Chilkat::CkBinData.new()
success = bd.LoadFile("qa_data/hamlet.xml")
if (success == false)
    print "Failed to load file to be hashed." + "\n";
    exit
end

ecdsa = Chilkat::CkEcc.new()
prng = Chilkat::CkPrng.new()

# Sign the sha256 hash of the data.  Return the ECDSA signature in the base64 encoding.
print "ECDSA signing the sha256 hash of the data..." + "\n";
sig = ecdsa.signBd(bd,"sha256","base64",privKey,prng)
print "sig = " + sig + "\n";

# Verify the signature against the original data.
# (We must use the same hash algorithm that was used when signing.)

# Load the public key that corresponds to the private key used for signing.
pubKey = Chilkat::CkPublicKey.new()
success = pubKey.LoadFromFile("qa_data/ecc/secp256r1-pub.pem")
if (success == false)
    print pubKey.lastErrorText() + "\n";
    exit
end

ecc2 = Chilkat::CkEcc.new()
result = ecc2.VerifyBd(bd,"sha256",sig,"base64",pubKey)
if (result != 1)
    print ecc2.lastErrorText() + "\n";
    exit
end

print "Verified!" + "\n";

# ----------------------------------------------------------------------------------------
# Let's do the same thing, but with sha384 hashing...

print "--------------------------------------------" + "\n";
print "ECDSA signing the sha384 hash of the data..." + "\n";

sig = ecdsa.signBd(bd,"sha384","base64",privKey,prng)
print "sig = " + sig + "\n";

result = ecc2.VerifyBd(bd,"sha384",sig,"base64",pubKey)
if (result != 1)
    print ecc2.lastErrorText() + "\n";
    exit
end

print "Verified!" + "\n";