RSA Encrypt and Decrypt Credit Card Numbers

Python 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 Python Module Downloads for Windows, Linux, and MAC OS X

import sys
import chilkat

rsa = chilkat.CkRsa()

success = rsa.UnlockComponent("Anything for 30-day trial")
if (success != True):
    print rsa.lastErrorText()
    sys.exit()

key = chilkat.CkPrivateKey()

#  Load an RSA private key from a PKCS8 file:
success = key.LoadPkcs8File("rsaPrivateKey.p8")
if (success != True):
    print key.lastErrorText()
    sys.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 != True):
    print rsa.lastErrorText()
    sys.exit()

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

usePrivateKey = False
rsa.put_EncodingMode("base64")
encryptedStr = rsa.encryptStringENC(ccNumber,usePrivateKey)
print "Encrypted:"
print encryptedStr

#  Now decrypt:
rsaDecryptor = chilkat.CkRsa()

rsaDecryptor.put_EncodingMode("base64")
rsaDecryptor.ImportPrivateKey(keyXml)

usePrivateKey = True
decryptedStr = rsaDecryptor.decryptStringENC(encryptedStr,usePrivateKey)

print "Decrypted:"
print decryptedStr

#  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.