DataFlex

Create P7M Using Pre-Installed Windows Certificate

See more Digital Signatures Examples

Demonstrates how to sign a file creating a .p7m file as output. The .p7m contains the signed contents of the original file. It can be verified and restored by calling VerifyP7M.

This example is for Windows only. It automatically searches and locates the desired certificate in the Current User or Local Machine certificate stores. (The certificate must have been pre-installed on the Windows machine, and it must have the private key available. The private key can be located on a USB Authentication Token / Smart Card. If so, then Chilkat *should* automatically use the private key located on the device.)

DataFlex

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Handle hoCrypt
    String sCertSubjectCN
    Variant vCert
    Handle hoCert
    String sInFile
    String sOutputFile
    String sTemp1
    Boolean bTemp1

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

    Move "Matt" To sCertSubjectCN

    Get Create (RefClass(cComChilkatCert)) To hoCert
    If (Not(IsComObjectCreated(hoCert))) Begin
        Send CreateComObject of hoCert
    End

    // Locate and load the certificate by the common name (subject CN).
    // This searches the Windows registry-based Current User and Local Machine
    // certificate stores for the certificate.  
    Get ComLoadByCommonName Of hoCert sCertSubjectCN To iSuccess
    If (iSuccess <> True) Begin
        Showln "Failed to find certificate."
        Procedure_Return
    End

    // Make sure a private key is available.
    Get ComHasPrivateKey Of hoCert To bTemp1
    If (bTemp1 <> True) Begin
        Showln "This certificate does not have a private key located in the Windows protected store, or on a USB device."
        Procedure_Return
    End

    // Specify the cert (and implicitly the private key) to be used for signing.
    Get pvComObject of hoCert to vCert
    Get ComSetSigningCert Of hoCrypt vCert To iSuccess

    // -----------------------------------------------------------------------------------------
    // Also see Chilkat's online tool to examine a .p7m and generate code to duplicate the .p7m
    // -----------------------------------------------------------------------------------------

    // We can sign any type of file, creating a .p7m as output:
    Move "qa_data/pdf/fishing.pdf" To sInFile
    Move "qa_output/fishing.pdf.p7m" To sOutputFile
    Get ComCreateP7M Of hoCrypt sInFile sOutputFile To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoCrypt To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Verify and restore the original file:
    Get pvComObject of hoCert to vCert
    Get ComSetVerifyCert Of hoCrypt vCert To iSuccess

    Move sOutputFile To sInFile
    Move "qa_output/restored.pdf" To sOutputFile

    Get ComVerifyP7M Of hoCrypt sInFile sOutputFile To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoCrypt To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Showln "Success!"


End_Procedure