(Perl) RSA Sign Binary Data and Verify (Recover the Original Data)

Demonstrates how to RSA sign binary data and then verify/recover the original data.

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

Chilkat Perl Downloads Perl Module for Windows, MacOS, Linux, Alpine Linux, Solaris

use 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 != 1) {
    print $privKey->lastErrorText() . "\r\n";
    exit;
}

$rsa = chilkat::CkRsa->new();
$rsa->ImportPrivateKeyObj($privKey);

# We have some binary data (in hex) to sign
$originalData = "0102030405060708090A";
$bd = chilkat::CkBinData->new();
$bd->AppendEncoded($originalData,"hex");

# If successful, the contents of bd are replaced with the RSA signature.
$success = $rsa->OpenSslSignBd($bd);
if ($success != 1) {
    print $rsa->lastErrorText() . "\r\n";
    exit;
}

# Show the RSA signature in base64
print $bd->getEncoded("base64") . "\r\n";

# ------------------------------------------
# Get the public key from the private key
# pubKey is a PublicKey
$pubKey = $privKey->GetPublicKey();

# Verify the signature and extract the original data.
$rsa2 = chilkat::CkRsa->new();
$rsa2->ImportPublicKeyObj($pubKey);

$bVerified = $rsa2->OpenSslVerifyBd($bd);
print "signature verified: " . $bVerified . "\r\n";

# Show the original data:
print "original data: " . $bd->getEncoded("hex") . "\r\n";