(DataFlex) RSA Encrypt and Decrypt Credit Card Numbers

DataFlex 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 ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

Use ChilkatAx-win32.pkg

Procedure Test
    Handle hoRsa
    Handle hoKey
    Boolean iSuccess
    String sKeyXml
    String sCcNumber
    Boolean iUsePrivateKey
    String sEncryptedStr
Decryptor    Handle hoRsaDecryptor
    String sDecryptedStr
    String sTemp1

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

    Get Create (RefClass(cComChilkatRsa)) To hoRsa
    If (Not(IsComObjectCreated(hoRsa))) Begin
        Send CreateComObject of hoRsa
    End

    Get Create (RefClass(cComChilkatPrivateKey)) To hoKey
    If (Not(IsComObjectCreated(hoKey))) Begin
        Send CreateComObject of hoKey
    End

    // Load an RSA private key from a file:
    Get ComLoadAnyFormatFile Of hoKey "rsaPrivateKey.key" "" To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoKey To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Get the key as XML:

    Get ComGetXml Of hoKey To sKeyXml

    // 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.
    Get ComImportPublicKey Of hoRsa sKeyXml To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoRsa To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Encrypt a VISA credit card number:
    // 1234-5678-0000-9999
    Move "1234567800009999" To sCcNumber

    Move False To iUsePrivateKey
    Set ComEncodingMode Of hoRsa To "base64"
    Get ComEncryptStringENC Of hoRsa sCcNumber iUsePrivateKey To sEncryptedStr
    Showln "Encrypted:"
    Showln sEncryptedStr

    // Now decrypt:
    Get Create (RefClass(cComChilkatRsa)) To hoRsaDecryptor
    If (Not(IsComObjectCreated(hoRsaDecryptor))) Begin
        Send CreateComObject of hoRsaDecryptor
    End

    Set ComEncodingMode Of hoRsaDecryptor To "base64"
    Get ComImportPrivateKey Of hoRsaDecryptor sKeyXml To iSuccess

    Move True To iUsePrivateKey
    Get ComDecryptStringENC Of hoRsaDecryptor sEncryptedStr iUsePrivateKey To sDecryptedStr

    Showln "Decrypted:"
    Showln sDecryptedStr

    // 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


End_Procedure