Lianja

RSA Encrypt and Decrypt Credit Card Numbers

See more RSA Examples

_LANGUAGE_ 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.) Lianja

llSuccess = .F.

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

loRsa = createobject("CkRsa")

loPrivKey = createobject("CkPrivateKey")

// Load an RSA private key from a file:
llSuccess = loPrivKey.LoadAnyFormatFile("rsaPrivateKey.key","")
if (llSuccess = .F.) then
    ? loPrivKey.LastErrorText
    release loRsa
    release loPrivKey
    return
endif

// Get the public part of the private key.
loPubKey = createobject("CkPublicKey")
loPrivKey.ToPublicKey(loPubKey)

llSuccess = loRsa.UsePublicKey(loPubKey)
if (llSuccess = .F.) then
    ? loRsa.LastErrorText
    release loRsa
    release loPrivKey
    release loPubKey
    return
endif

// Encrypt a VISA credit card number:
// 1234-5678-0000-9999
lcCcNumber = "1234567800009999"

llUsePrivateKey = .F.
loRsa.EncodingMode = "base64"
lcEncryptedStr = loRsa.EncryptStringENC(lcCcNumber,llUsePrivateKey)
? "Encrypted:"
? lcEncryptedStr

// Now decrypt:
loRsaDecryptor = createobject("CkRsa")

loRsaDecryptor.EncodingMode = "base64"
loRsaDecryptor.UsePrivateKey(loPrivKey)

llUsePrivateKey = .T.
lcDecryptedStr = loRsaDecryptor.DecryptStringENC(lcEncryptedStr,llUsePrivateKey)

? "Decrypted:"
? lcDecryptedStr

// 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


release loRsa
release loPrivKey
release loPubKey
release loRsaDecryptor