(Perl) 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 Perl Downloads Perl Module for Windows, MacOS, Linux, Alpine Linux, Solaris

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

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

# pubKey is a PublicKey
$pubKey = $cert->ExportPublicKey();

# Get the private key in XML format:
$pubKeyXml = $pubKey->getXml();

$rsa2 = chilkat::CkRsa->new();
$success = $rsa2->ImportPublicKey($pubKeyXml);
if ($success != 1) {
    print $rsa2->lastErrorText() . "\r\n";
    exit;
}

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

print "Signature verified!" . "\r\n";

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