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PKCS11 Find Certificate with Key Usage on Smart Card or USB Token

See more PKCS11 Examples

Demonstrates how to find and return the 1st certificate on a smart card or USB token with a desired intended key usage.

Note: This example requires Chilkat v9.5.0.91 or later.

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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();

    pkcs11.setSharedLibPath("aetpkss1.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.
    //
    // If we don't authenticate, then we won't be able to see the private keys, and thus
    // we won't know which certificates have an associated private key stored on the smart card.

    // The smart card PIN is passed to the Login method.
    // userType 1 indicates a "Normal User".
    const user_type = 1;
    const pin = "0000";
    pkcs11.login(user_type, pin) catch {
        std.debug.print("{s}\n", .{try pkcs11.getLastErrorText(alloc)});
        try pkcs11.closeSession();
        return;
    };

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

    const cert = try chilkat.Cert.init();
    defer cert.deinit();

    // Find a certificate with an intended key usage.
    // Possible key usages to find are:
    //
    // DigitalSignature
    // NonRepudiation
    // KeyEncipherment
    // DataEncipherment
    // CertificateSigning
    // CrlSigning
    //
    // To find a cert having any one of several usages, pass a comma-separated list of usages:
    if (pkcs11.findCert("keyUsage", "NonRepudiation,DigitalSignature", cert)) {
        std.debug.print("Cert with private key: {s}\n", .{try cert.getSubjectCN(alloc)});
    } else |_| {
        std.debug.print("No certificates having the intended key usage were found.\n", .{});
    }

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

    // 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", .{});
}