C++

Add a Detached Signature (Separate Key, Header Control)

Demonstrates the Chilkat Mime.AddDetachedSignaturePk2 method, which creates a detached signature with a separately supplied certificate and private key, and a third argument controlling transfer of the existing message header fields 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: This combines the two variations — certificate and key supplied separately, plus explicit header placement — for the case that needs both. It is the most flexible of the detached-signature methods; choose it when your key material is separate and you also care about where the message headers end up on the signed result.

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C++

#include <CkMime.h>
#include <CkCert.h>
#include <CkPrivateKey.h>

void ChilkatSample(void)
    {
    bool success = false;

    CkMime mime;
    success = mime.SetBodyFromPlainText("This message will be signed.");
    if (success == false) {
        std::cout << mime.lastErrorText() << "\r\n";
        return;
    }

    //  Load the certificate and its private key separately.
    CkCert cert;
    success = cert.LoadFromFile("qa_data/signer.cer");
    if (success == false) {
        std::cout << cert.lastErrorText() << "\r\n";
        return;
    }

    CkPrivateKey privKey;
    success = privKey.LoadPemFile("qa_data/signer_privkey.pem");
    if (success == false) {
        std::cout << privKey.lastErrorText() << "\r\n";
        return;
    }

    //  Create a detached signature with separately supplied cert and private key, where the 3rd
    //  argument controls whether the existing message header fields are transferred to the new outer
    //  multipart/signed entity.
    bool transferHeaderFields = true;
    success = mime.AddDetachedSignaturePk2(cert,privKey,transferHeaderFields);
    if (success == false) {
        std::cout << mime.lastErrorText() << "\r\n";
        return;
    }

    success = mime.SaveMime("qa_output/signed.eml");
    if (success == false) {
        std::cout << mime.lastErrorText() << "\r\n";
        return;
    }

    std::cout << "Detached signature added (headers transferred)." << "\r\n";
    }