Use Certificate and Private Key PEM Files to Create a Digital Signature

Demonstrates how to load a digital certificate from a PEM file, load it's corresponding private key from a PEM file, save the private key to a key container (if necessary), link the certificate to the key container, and use it to create a digital signature.

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Chilkat.Cert cert = new Chilkat.Cert();

//  Load the cert from a PEM file;
cert.LoadFromFile("cert.pem");

Chilkat.PrivateKey pkey = new Chilkat.PrivateKey();

//  Load the private key from an RSA PEM file:
pkey.LoadPemFile("pkey_rsa.pem");

bool success;

//  If the "chilkat" key container does not already exist,
//  we'll create it and import the private key:
Chilkat.KeyContainer container = new Chilkat.KeyContainer();
bool needPrivateKeyAccess;
needPrivateKeyAccess = true;
bool machineKeyset;
machineKeyset = false;
if (container.OpenContainer("chilkat",needPrivateKeyAccess,machineKeyset) == false) {

    //  We need to create the key container and import
    //  the private key:
    success = container.CreateContainer("chilkat",machineKeyset);
    if (success == true) {
        bool isKeyExchangePair;
        isKeyExchangePair = false;
        success = container.ImportPrivateKey(pkey,isKeyExchangePair);
        if (success == false) {
            textBox1.Text += "Failed to import private key into key container" + "\r\n";
            return;
        }

    }
    else {
        textBox1.Text += "Failed to create key container" + "\r\n";
        return;
    }

}

//  At this point, the key container contains the private key.
//  Link the certificate with the key container:
bool bForSigning;
bForSigning = true;
success = cert.LinkPrivateKey("chilkat",machineKeyset,bForSigning);
if (success == false) {
    textBox1.Text += "Failed to link certificate with key container" + "\r\n";
    return;
}

//  Use Chilkat Crypt (a non-freeware component) to create
//  a digital signature using the certificate w/ private key:
Chilkat.Crypt2 crypt = new Chilkat.Crypt2();

//  Any string argument automatically begins the 30-day trial.

success = crypt.UnlockComponent("30-day trial");
if (success != true) {
    MessageBox.Show("Crypt component unlock failed");
    return;
}

//  Tell the crypt component to use this cert.
crypt.SetSigningCert(cert);

//  We can sign any type of file, creating a .p7s as output:
success = crypt.CreateP7S("license.rtf","license.p7s");
if (success == false) {
    MessageBox.Show(crypt.LastErrorText);

    return;
}

textBox1.Text += crypt.LastErrorText + "\r\n";

//  Verify and restore the original file:
crypt.SetVerifyCert(cert);

success = crypt.VerifyP7S("license.rtf","license.p7s");
if (success == false) {
    MessageBox.Show(crypt.LastErrorText);

    return;
}

MessageBox.Show("Success!");

//  The Chilkat Certificate, Certificate Store, Private Key,
//  Public Key, and Key Container classes / objects are freeware.

//  They are used by and included with the Chilkat Email,
//  Crypt, S/MIME, and other commercial Chilkat components.