Swift

Add a Detached Signature with a Separate Private Key

Demonstrates the Chilkat Mime.AddDetachedSignaturePk method, which creates a detached signature using a signer certificate and its separately supplied private key. The first argument is the Cert and the second is the PrivateKey.

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: Sometimes the certificate and its private key live apart — a .cer alongside a PEM key file, for instance — rather than bundled in a single PFX. This method pairs them explicitly for signing, whereas AddDetachedSignature expects a Cert that already provides its key. The result is the same multipart/signed message.

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Swift


func chilkatTest() {
    var success: Bool = false

    let mime = CkoMime()!
    success = mime.setBody(fromPlainText: "This message will be signed.")
    if success == false {
        print("\(mime.lastErrorText!)")
        return
    }

    //  Load the certificate and its private key separately.
    let cert = CkoCert()!
    success = cert.load(fromFile: "qa_data/signer.cer")
    if success == false {
        print("\(cert.lastErrorText!)")
        return
    }

    let privKey = CkoPrivateKey()!
    success = privKey.loadPemFile(path: "qa_data/signer_privkey.pem")
    if success == false {
        print("\(privKey.lastErrorText!)")
        return
    }

    //  Create a detached signature when the certificate and private key are supplied separately.  The
    //  1st argument is the signer certificate and the 2nd is its private key.
    success = mime.addDetachedSignaturePk(cert: cert, privateKey: privKey)
    if success == false {
        print("\(mime.lastErrorText!)")
        return
    }

    success = mime.save(path: "qa_output/signed.eml")
    if success == false {
        print("\(mime.lastErrorText!)")
        return
    }

    print("Detached signature added.")

}