(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.)

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

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

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Handle hoRsa
    Variant vPrivKey
    Handle hoPrivKey
    Variant vPubKey
    Handle hoPubKey
    String sCcNumber
    Boolean iUsePrivateKey
    String sEncryptedStr
    Handle hoRsaDecryptor
    String sDecryptedStr
    String sTemp1

    Move False To iSuccess

    // 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 hoPrivKey
    If (Not(IsComObjectCreated(hoPrivKey))) Begin
        Send CreateComObject of hoPrivKey
    End

    // Load an RSA private key from a file:
    Get ComLoadAnyFormatFile Of hoPrivKey "rsaPrivateKey.key" "" To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoPrivKey To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Get the public part of the private key.
    Get Create (RefClass(cComChilkatPublicKey)) To hoPubKey
    If (Not(IsComObjectCreated(hoPubKey))) Begin
        Send CreateComObject of hoPubKey
    End
    Get pvComObject of hoPubKey to vPubKey
    Get ComToPublicKey Of hoPrivKey vPubKey To iSuccess

    Get pvComObject of hoPubKey to vPubKey
    Get ComUsePublicKey Of hoRsa vPubKey To iSuccess
    If (iSuccess = False) 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 pvComObject of hoPrivKey to vPrivKey
    Get ComUsePrivateKey Of hoRsaDecryptor vPrivKey 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