Lianja

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.

Chilkat Lianja Downloads

Download Chilkat for Lianja

Lianja

llSuccess = .F.

loMime = createobject("CkMime")
llSuccess = loMime.SetBodyFromPlainText("This message will be signed.")
if (llSuccess = .F.) then
    ? loMime.LastErrorText
    release loMime
    return
endif

//  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.
lcPfxPassword = "myPfxPassword"
loCert = createobject("CkCert")
llSuccess = loCert.LoadPfxFile("qa_data/signer.pfx",lcPfxPassword)
if (llSuccess = .F.) then
    ? loCert.LastErrorText
    release loMime
    release loCert
    return
endif

//  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.
llTransferHeaderFields = .T.
llSuccess = loMime.AddDetachedSignature2(loCert,llTransferHeaderFields)
if (llSuccess = .F.) then
    ? loMime.LastErrorText
    release loMime
    release loCert
    return
endif

llSuccess = loMime.SaveMime("qa_output/signed.eml")
if (llSuccess = .F.) then
    ? loMime.LastErrorText
    release loMime
    release loCert
    return
endif

? "Detached signature added (headers transferred)."


release loMime
release loCert