Zig Requires Chilkat v11.0.0+

Get a Certificate's Key Size

See more Certificates Examples

Demonstrates how to get the RSA key size of a certificate (for example, 1024-bit, 2048-bit, etc.) Zig

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

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

    // For this example, I have a certificate in raw base64 format (not PEM),
    // that looks like this:  "MIIGkDCCBHigAwIBAgIUMDA ... s/iqLsLA=="
    const sb_cert_base64 = try chilkat.StringBuilder.init();
    defer sb_cert_base64.deinit();
    try sb_cert_base64.loadFile("qa_data/certs/base64Cert.txt", "utf-8");

    const cert = try chilkat.Cert.init();
    defer cert.deinit();
    cert.loadFromBase64(try sb_cert_base64.getAsString(alloc)) catch {
        std.debug.print("{s}\n", .{try cert.getLastErrorText(alloc)});
        return;
    };

    // Get the public key.
    const pub_key = try chilkat.PublicKey.init();
    defer pub_key.deinit();
    cert.getPublicKey(pub_key) catch {};

    var num_bits: i32 = pub_key.getKeySize();
    std.debug.print("Number of bits = {d}\n", .{num_bits});

    // If using an older version of Chilkat, the key size can be obtained like this:
    const xml = try chilkat.Xml.init();
    defer xml.deinit();
    xml.loadXml(try pub_key.getXml(alloc)) catch {};

    const bin_dat = try chilkat.BinData.init();
    defer bin_dat.deinit();
    bin_dat.appendEncoded(try xml.getChildContent(alloc, "Modulus"), "base64") catch {};

    num_bits = 8 * bin_dat.getNumBytes();
    std.debug.print("Number of bits = {d}\n", .{num_bits});
}