DataFlex

Add a Detached Signature (Header Placement Control)

Demonstrates the Chilkat Mime.AddDetachedSignature2 method, which creates the same multipart/signed structure as AddDetachedSignature, with a second argument controlling whether the existing message header fields are transferred to the new outer entity.

Note: The file paths are relative to the application's current working directory. Absolute paths may also be used. Supply the paths appropriate to your own environment.

Background: Signing wraps the content in a new outer multipart/signed, which raises the question of where the message-level headers (Subject, From, To) should live. This variant lets you choose: transfer them up to the outer entity so the signed message looks like a normal email, or leave them on the inner part. Transferring is typical for email; the finer control matters when the signed entity is embedded in a larger structure.

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DataFlex

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    Handle hoMime
    String sPfxPassword
    Variant vCert
    Handle hoCert
    Boolean iTransferHeaderFields
    String sTemp1

    Move False To iSuccess

    Get Create (RefClass(cComChilkatMime)) To hoMime
    If (Not(IsComObjectCreated(hoMime))) Begin
        Send CreateComObject of hoMime
    End
    Get ComSetBodyFromPlainText Of hoMime "This message will be signed." To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoMime To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    //  Load the signing certificate (which must have access to its private key) from a PFX file.
    //  The PFX password should come from a secure source rather than being hard-coded.
    Move "myPfxPassword" To sPfxPassword
    Get Create (RefClass(cComChilkatCert)) To hoCert
    If (Not(IsComObjectCreated(hoCert))) Begin
        Send CreateComObject of hoCert
    End
    Get ComLoadPfxFile Of hoCert "qa_data/signer.pfx" sPfxPassword To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoCert To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    //  AddDetachedSignature2 is the same as AddDetachedSignature, but the 2nd argument controls whether
    //  the existing message header fields are transferred to the new outer multipart/signed entity.
    Move True To iTransferHeaderFields
    Get pvComObject of hoCert to vCert
    Get ComAddDetachedSignature2 Of hoMime vCert iTransferHeaderFields To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoMime To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get ComSaveMime Of hoMime "qa_output/signed.eml" To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoMime To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Showln "Detached signature added (headers transferred)."


End_Procedure