(Perl) RSA Encrypt and Decrypt Credit Card Numbers

Perl sample code to RSA public-key encrypt and decrypt credit card numbers. The RSA key is loaded from an unencrypted PKCS8 file. Chilkat provides many ways of setting the key -- loading from both encrypted and unencrypted PEM, PKCS8, DER, PVK, etc. Keys may be loaded from files or in-memory representations. (The RSA component also provides the ability to generate RSA keys.)

Note: This example requires Chilkat v11.0.0 or greater.

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use chilkat();

$success = 0;

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

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

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

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

# Get the public part of the private key.
$pubKey = chilkat::CkPublicKey->new();
$privKey->ToPublicKey($pubKey);

$success = $rsa->UsePublicKey($pubKey);
if ($success == 0) {
    print $rsa->lastErrorText() . "\r\n";
    exit;
}

# Encrypt a VISA credit card number:
# 1234-5678-0000-9999
$ccNumber = "1234567800009999";

$usePrivateKey = 0;
$rsa->put_EncodingMode("base64");
$encryptedStr = $rsa->encryptStringENC($ccNumber,$usePrivateKey);
print "Encrypted:" . "\r\n";
print $encryptedStr . "\r\n";

# Now decrypt:
$rsaDecryptor = chilkat::CkRsa->new();

$rsaDecryptor->put_EncodingMode("base64");
$rsaDecryptor->UsePrivateKey($privKey);

$usePrivateKey = 1;
$decryptedStr = $rsaDecryptor->decryptStringENC($encryptedStr,$usePrivateKey);

print "Decrypted:" . "\r\n";
print $decryptedStr . "\r\n";

# Important: RSA encryption should only be used to encrypt small amounts of data.
# It is typically used for encrypting symmetric encryption
# keys such that a symmetric encryption algorithm, such as 
# AES is then used to encrypt/decrypt bulk data