Unicode C++

Set the DKIM Signing Private Key

Demonstrates the Chilkat Dkim.SetDkimPrivateKey method, which supplies the RSA private key used by DkimSign. The only argument is a PrivateKey object. The source key may be destroyed after this returns, and the configured key can be reused for multiple signatures.

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: DKIM proves a message really came from its domain by signing it with a private key that only the domain owner holds; recipients verify with the matching public key published in the domain's DNS. This method loads that private half into the Dkim object once, so a mail server can sign every outgoing message without re-reading the key each time. Because the key is the domain's signing secret, it should be protected like any other private key and never committed to source.

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#include <CkDkimW.h>
#include <CkPrivateKeyW.h>

void ChilkatSample(void)
    {
    bool success = false;

    //  Demonstrates the Dkim.SetDkimPrivateKey method, which supplies the RSA private key used by
    //  DkimSign.  The only argument is a PrivateKey object.

    CkDkimW dkim;

    //  Load the RSA private key that corresponds to the public key published in the domain's DNS.
    CkPrivateKeyW privKey;
    success = privKey.LoadPemFile(L"qa_data/dkim_private.pem");
    if (success == false) {
        wprintf(L"%s\n",privKey.lastErrorText());
        return;
    }

    //  Copy the key into the Dkim object.  The PrivateKey object may be destroyed afterward, and the
    //  configured key can be reused for multiple signatures.
    success = dkim.SetDkimPrivateKey(privKey);
    if (success == false) {
        wprintf(L"%s\n",dkim.lastErrorText());
        return;
    }

    wprintf(L"DKIM private key configured.\n");
    }