Perl

RSA Signature/Verify with .key and .cer

See more RSA Examples

Demonstrates how to use a .key file (private key) and digital certificate (.cer, public key) to create and verify an RSA signature. Perl

use chilkat();

$success = 0;

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

$privKey = chilkat::CkPrivateKey->new();

# Load the private key from an RSA .key file:
$success = $privKey->LoadPemFile("privateKey.key");
if ($success == 0) {
    print $privKey->lastErrorText() . "\r\n";
    exit;
}

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

# Import the private key into the RSA component:
$success = $rsa->UsePrivateKey($privKey);
if ($success == 0) {
    print $rsa->lastErrorText() . "\r\n";
    exit;
}

# Create the signature as a hex string:
$rsa->put_EncodingMode("hex");

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

# Sign the string using the sha256 hash algorithm.
# Other valid choices are "md2", "sha1", "sha384",
# "sha512", and "md5".
$hexSig = $rsa->signStringENC($strData,"sha256");

print $hexSig . "\r\n";

# Load a digital certificate from a .cer file:
$cert = chilkat::CkCert->new();

$success = $cert->LoadFromFile("myCert.cer");
if ($success == 0) {
    print $cert->lastErrorText() . "\r\n";
    exit;
}

$pubKey = chilkat::CkPublicKey->new();
$cert->GetPublicKey($pubKey);

# Now verify using a new instance of the RSA object:
$rsa2 = chilkat::CkRsa->new();

# Import the public key into the RSA object:
$success = $rsa2->UsePublicKey($pubKey);
if ($success == 0) {
    print $rsa2->lastErrorText() . "\r\n";
    exit;
}

# The signature is a hex string, so make sure the EncodingMode is correct:
$rsa2->put_EncodingMode("hex");

# Verify the signature:
$success = $rsa2->VerifyStringENC($strData,"sha256",$hexSig);
if ($success == 0) {
    print $rsa2->lastErrorText() . "\r\n";
    exit;
}

print "Success." . "\r\n";