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PKCS11 Certificate Chain

See more PKCS11 Examples

Demonstrates how to make CA certs available for the certificate chain to be included when creating a signature (using a PKCS11 compatible smart card / USB token) such as for PDF, XMLDSig, etc.

Note: This example requires Chilkat v9.5.0.88 or later.

Zig

const std = @import("std");
const chilkat = @import("chilkat");

pub fn main(init: std.process.Init) !void {
    const alloc = init.arena.allocator();

    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    // Note: Chilkat's PKCS11 implementation runs on Windows, Linux, Mac OS X, and other supported operating systems.

    const pkcs11 = try chilkat.Pkcs11.init();
    defer pkcs11.deinit();

    // You will use the DLL (or shared lib) provided by your smart card vendor, or a DLL compatible with your smart card.
    // On Windows, if the DLL is located in C:\Windows\System32, specify only the filename.
    // Otherwise provide the full path.
    pkcs11.setSharedLibPath("bit4xpki.dll");

    pkcs11.initialize() catch {
        std.debug.print("{s}\n", .{try pkcs11.getLastErrorText(alloc)});
        return;
    };

    // Pass -1 for the slotID to open a session on the first non-empty slot.
    const slot_id = -1;

    // Open a session.
    const read_write = true;
    pkcs11.openSession(slot_id, read_write) catch {
        std.debug.print("{s}\n", .{try pkcs11.getLastErrorText(alloc)});
        return;
    };

    // Make it an authenticated session by calling Login.
    const user_type = 1;
    // Make sure to use the correct PIN for your smart card..
    const pin = "0000";
    pkcs11.login(user_type, pin) catch {
        std.debug.print("{s}\n", .{try pkcs11.getLastErrorText(alloc)});
        try pkcs11.closeSession();
        return;
    };

    // Get the certificate (on the smart card) that has a private key.
    const cert = try chilkat.Cert.init();
    defer cert.deinit();
    if (pkcs11.findCert("privateKey", "", cert)) {
        std.debug.print("Cert with private key: {s}\n", .{try cert.getSubjectCN(alloc)});
    } else |_| {
        std.debug.print("No certificates having a private key were found.\n", .{});
        try pkcs11.closeSession();
        return;
    }

    // If the certificates in the chain of authentication were contained on the smart card,
    // then Chilkat would already have them (via the FindCert function) and the certs in the chain will be automatically used
    // as needed when signing occurs.

    // If you have CA certs located elsewhere, such as in .cer files, you can make them available to Chilkat in the following way:

    const cert_vault = try chilkat.XmlCertVault.init();
    defer cert_vault.deinit();
    // Please review the methods available in the XML certificate vault class.  Different methods exist for adding certificates
    // from various sources, such as PEM, PFX, or in-memory sources..
    try cert_vault.addCertFile("someDir/caIntermediateCert.cer");
    // ...
    try cert_vault.addCertFile("someDir/caCert.cer");
    // (Your code should check the return value to make sure it succeeded.)

    cert.useCertVault(cert_vault) catch {
        std.debug.print("{s}\n", .{try cert.getLastErrorText(alloc)});
        try pkcs11.closeSession();
        return;
    };

    // --------------------------------------------------------------------------
    // At this point, we have the cert (and certs in the chain of authentication) to be used for signing.
    // The code for using the certificate in creating the digital signature, such as for a PDF, XML, etc., go here...

    // --------------------------------------------------------------------------

    // Revert to an unauthenticated session by calling Logout.
    pkcs11.logout() catch {
        std.debug.print("{s}\n", .{try pkcs11.getLastErrorText(alloc)});
        try pkcs11.closeSession();
        return;
    };

    // When finished, close the session.
    // It is important to close the session (memory leaks will occur if the session is not properly closed).
    pkcs11.closeSession() catch {
        std.debug.print("{s}\n", .{try pkcs11.getLastErrorText(alloc)});
        return;
    };

    std.debug.print("Success.\n", .{});
}