DataFlex

Demonstrate RSA Encrypt/Decrypt using BinData

See more RSA Examples

Demonstrates how to RSA encrypt and decrypt data contained in a Chilkat BinData object. DataFlex

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Variant vPubKey
    Handle hoPubKey
    Handle hoRsa
    Variant vBd
    Handle hoBd
    Integer i
    Variant vPrivKey
    Handle hoPrivKey
    String sPassword
    String sTemp1
    Integer iTemp1

    Move False To iSuccess

    // The RSA public key is used for encryption, and the private key for decryption.

    // The public key's role is to make encryption accessible to anyone while ensuring that
    // only the private key holder can decrypt the messages.
    // The public key is designed to be widely distributed so anyone can use it to encrypt messages
    // intended for the owner of the private key.

    // Load our 2048-bit RSA public key.
    Get Create (RefClass(cComChilkatPublicKey)) To hoPubKey
    If (Not(IsComObjectCreated(hoPubKey))) Begin
        Send CreateComObject of hoPubKey
    End
    // In all Chilkat methods expecting a path, you pass either absolute or relative paths.
    Get ComLoadFromFile Of hoPubKey "rsaKeys/myTestRsaPublic.pem" To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoPubKey To sTemp1
        Showln sTemp1
        Procedure_Return
    End

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

    // Tell RSA to use the public key.
    Get pvComObject of hoPubKey to vPubKey
    Get ComUsePublicKey Of hoRsa vPubKey To iSuccess

    // RSA encryption is for small amounts of data, on the order of 200 bytes or less.
    // The maximum number of bytes that can be RSA encrypted depends
    // on the RSA key size and padding scheme (OAEP padding vs PKCS#1 v1.5 padding).
    // For specific limits, see: RSA Encryption Maximum Number of Bytes

    // Create some binary data to encrypt.
    Get Create (RefClass(cComChilkatBinData)) To hoBd
    If (Not(IsComObjectCreated(hoBd))) Begin
        Send CreateComObject of hoBd
    End
    Move 0 To i
    For i From 0 To 49
        Get ComAppendByte Of hoBd i To iSuccess
    Loop

    // Show the bytes to be encrypted in hex format:
    Get ComGetEncoded Of hoBd "hex" To sTemp1
    Showln "To be encrypted: " sTemp1

    // To be encrypted: 000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F202122232425262728292A2B2C2D2E2F3031

    // RSA encrypt the contents of the bd, replacing the contents with the RSA encrypted data.
    Get pvComObject of hoBd to vBd
    Get ComEncryptBd Of hoRsa vBd False To iSuccess

    // Now it is encrypted.
    Get ComNumBytes Of hoBd To iTemp1
    Showln "Encrypted size = " iTemp1
    Get ComGetEncoded Of hoBd "hex" To sTemp1
    Showln sTemp1

    // Encrypted size = 256
    // 749ED9D0A8767C06C09AD9697F654F86B145F966722F9714902C4175BDBD02E68984ECF111D4D461
    // EDB4A8E677D399D19CCA60F35C6DE9972F4262880FE9D77DB75915393E8E7DB80AAB5E383013FAEB
    // 60C77D1E6FECC9A7C8426976416C6218FE7DA998EE063CE709E79C240F8625F4A56A0A33AFD63F7A
    // BA26F2A692B42E878C53B78602C725FE63FF961A46A2B9D436E5E3D9D64AE3F1D1F5AD5F5B47FCD69
    // 447306B77F2FD6D766CCAA1A110A3371586B43DF0D7FFE2220D1B305CF9371AC342F849FB0C90CD99E
    // C176928D877FE1C0DE1A7CB6EB824FEC7E1DCF90EF2C6BA9F1DFD3EBFBE89C51AF074DC6AE02E544A78
    // 5018C36D3D48B2EF5202AF61AC

    // ------------------------------------------------------------------------------------------------------------------------
    // Let's decrypt, which requires the matching private key...

    // Load the matching 2048-bit RSA private key.
    Get Create (RefClass(cComChilkatPrivateKey)) To hoPrivKey
    If (Not(IsComObjectCreated(hoPrivKey))) Begin
        Send CreateComObject of hoPrivKey
    End
    Move "secret" To sPassword
    Get ComLoadAnyFormatFile Of hoPrivKey "rsaKeys/myTestRsaPrivate.pem" sPassword To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoPrivKey To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Tell the RSA object to use the private key.
    Get pvComObject of hoPrivKey to vPrivKey
    Get ComUsePrivateKey Of hoRsa vPrivKey To iSuccess

    // Decrypt
    Get pvComObject of hoBd to vBd
    Get ComDecryptBd Of hoRsa vBd True To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoRsa To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Examine the contents of bd to see if it now contains the unencrypted original data.
    Get ComGetEncoded Of hoBd "hex" To sTemp1
    Showln "Decrypted: " sTemp1

    // Decrypted: 000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F202122232425262728292A2B2C2D2E2F3031


End_Procedure