(DataFlex) Encrypt File to PKCS7 .p7m

DataFlex example to public-key encrypt a file creating a PKCS#7 .p7m file as output. Also demonstrates how to decrypt the .p7m to recover the original file.

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

Use ChilkatAx-win32.pkg

Procedure Test
    Handle hoCrypt
    Variant vEncryptCert
    Handle hoEncryptCert
    Boolean iSuccess
    String sInFile
    String sOutFile
    Handle hoDecrypt
    String sPfxFilename
    String sPfxPassword
    String sTemp1

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

    Get Create (RefClass(cComChilkatCrypt2)) To hoCrypt
    If (Not(IsComObjectCreated(hoCrypt))) Begin
        Send CreateComObject of hoCrypt
    End

    // Indicate the public-key encryption is to be used.
    // Do this by setting the encryption algorithm equal 
    // to "PKI" (an acroynm for public-key infrastructure).
    Set ComCryptAlgorithm Of hoCrypt To "PKI"

    // Indicate the inner symmetric encryption algorithm to be used.
    // possible values are "aes", "des", "3des", and "rc2".
    // For this example, we'll use 256-bit AES encryption.
    Set ComPkcs7CryptAlg Of hoCrypt To "aes"
    Set ComKeyLength Of hoCrypt To 256

    // To encrypt, only a certificate w/ public key is needed.
    // (The certificate w/ private key is required for decryption.)

    // The LoadFromFile method can load virtually any certificate format:
    // 1. DER encoded binary X.509 (.CER)
    // 2. Base-64 encoded X.509 (.CER)
    // 3. Cryptographic Message Syntax Standard - PKCS #7 Certificates (.P7B)
    // 4. PEM format
    Get Create (RefClass(cComChilkatCert)) To hoEncryptCert
    If (Not(IsComObjectCreated(hoEncryptCert))) Begin
        Send CreateComObject of hoEncryptCert
    End
    Get ComLoadFromFile Of hoEncryptCert "/Users/chilkat/testData/cer/acme.cer" To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoEncryptCert To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Tell the crypt object to use the certificate for encrypting:
    Get pvComObject of hoEncryptCert to vEncryptCert
    Send ComAddEncryptCert To hoCrypt vEncryptCert

    // Encrypt a file, producing a .p7m as output.
    // The input file is unchanged, the output .p7m contains the encrypted
    // contents of the input file.
    Move "/Users/chilkat/testData/pdf/sample.pdf" To sInFile
    Move "/Users/chilkat/testData/p7m/sample.pdf.p7m" To sOutFile
    Get ComCkEncryptFile Of hoCrypt sInFile sOutFile To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoCrypt To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // For demonstration purposes, a different instance of the object will be used
    // for decryption.
    Get Create (RefClass(cComChilkatCrypt2)) To hoDecrypt
    If (Not(IsComObjectCreated(hoDecrypt))) Begin
        Send CreateComObject of hoDecrypt
    End

    // To decrypt, the certificate w/ private key is required.  A PFX (also known
    // as PKCS#12) is a common secure container for certs and private keys.
    Move "/Users/chilkat/testData/pfx/acme.pfx" To sPfxFilename
    Move "secret" To sPfxPassword

    // Tell the component to look in the PFX file for certs and private keys.
    Get ComAddPfxSourceFile Of hoDecrypt sPfxFilename sPfxPassword To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoDecrypt To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Tell the decrypt object that PKI (public key encryption) is to be used
    // for decryptiong.
    Set ComCryptAlgorithm Of hoDecrypt To "PKI"
    // There is no need to set the Pkcs7Alg or KeyLength because this information
    // is contained within the .p7m

    // Decrypt the .p7m
    Move "/Users/chilkat/testData/p7m/sample.pdf.p7m" To sInFile
    Move "/Users/chilkat/testData/pdf/recovered.pdf" To sOutFile
    Get ComCkDecryptFile Of hoDecrypt sInFile sOutFile To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoDecrypt To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Showln "Success!"


End_Procedure