(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.)

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.

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

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

# Load an RSA private key from a file:
$success = $key->LoadAnyFormatFile("rsaPrivateKey.key","");
if ($success != 1) {
    print $key->lastErrorText() . "\r\n";
    exit;
}

# Get the key as XML:

$keyXml = $key->getXml();

# We'll encrypt with the public key and decrypt with the private
# key.  (It's also possible to do the reverse.)
# Note: An RSA private key is composed of different parts internally: modulus, exponent, P, Q, etc.
# An RSA public-key is a sub-set of the private key.
# Therefore, when you have a private key, you really have
# both public and private keys.
$success = $rsa->ImportPublicKey($keyXml);
if ($success != 1) {
    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");
$success = $rsaDecryptor->ImportPrivateKey($keyXml);

$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