Zig

Get Certificate Authority Information Access

See more Certificates Examples

Demonstrates how to get a certificate's Authority Information Access extension data (if it exists).

Note: This example requires Chilkat v9.5.0.76 or greater.

Zig

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

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

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

    cert.loadFromFile("qa_data/certs/test_haswdt.cer") catch {
        std.debug.print("{s}\n", .{try cert.getLastErrorText(alloc)});
        return;
    };

    // Get the Authority Information Access extension, which is at OID 1.3.6.1.5.5.7.1.1
    const extension_xml_str = cert.getExtensionAsXml(alloc, "1.3.6.1.5.5.7.1.1") catch {
        std.debug.print("Certificate does not have the AuthInfoAccess extension.\n", .{});
        return;
    };

    const xml = try chilkat.Xml.init();
    defer xml.deinit();
    xml.loadXml(extension_xml_str) catch {};

    // See what we have..
    std.debug.print("{s}\n", .{try xml.getXml(alloc)});

    // We should get XML like this:

    // <?xml version="1.0" encoding="utf-8" ?>
    // <sequence>
    //     <sequence>
    //         <oid>1.3.6.1.5.5.7.48.2</oid>
    //         <contextSpecific tag="6" constructed="0">aHR0cDovL2NydC5jb21vZG9jYS5jb20vQ09NT0RPUlNBQ2xpZW50QXV0aGVudGljYXRpb25hbmRTZWN1
    // cmVFbWFpbENBLmNydA==</contextSpecific>
    //     </sequence>
    //     <sequence>
    //         <oid>1.3.6.1.5.5.7.48.1</oid>
    //         <contextSpecific tag="6" constructed="0">aHR0cDovL29jc3AuY29tb2RvY2EuY29t</contextSpecific>
    //     </sequence>
    // </sequence>

    // Typically, a certificate AIA(Authority Information access) contains 2 parts:
    //
    //     On-line Certificate Status Protocol (1.3.6.1.5.5.7.48.1)
    //     Certification Authority Issuer (1.3.6.1.5.5.7.48.2)
    //
    // The base64 content for each OID (in this case) is just a string.
    // The data can be accessed and decoded like this:

    const sb_ocsp = try chilkat.StringBuilder.init();
    defer sb_ocsp.deinit();
    if (xml.getChildContentSb("/C/oid,1.3.6.1.5.5.7.48.1|++", sb_ocsp)) {
        sb_ocsp.decode("base64", "utf-8") catch {};
        std.debug.print("1.3.6.1.5.5.7.48.1:  {s}\n", .{try sb_ocsp.getAsString(alloc)});
    } else |_| {}

    const sb_issuer = try chilkat.StringBuilder.init();
    defer sb_issuer.deinit();
    if (xml.getChildContentSb("/C/oid,1.3.6.1.5.5.7.48.2|++", sb_issuer)) {
        sb_issuer.decode("base64", "utf-8") catch {};
        std.debug.print("1.3.6.1.5.5.7.48.2:  {s}\n", .{try sb_issuer.getAsString(alloc)});
    } else |_| {}

    // The output looks like this:

    // 1.3.6.1.5.5.7.48.1:  http://ocsp.comodoca.com
    // 1.3.6.1.5.5.7.48.2:  http://crt.comodoca.com/COMODORSAClientAuthenticationandSecureEmailCA.crt

    // -------------------------------------------------------------------------------
    // Note: The Chilkat path passed to GetChildContentSb is composed of two commands:
    // The first command is "/C/oid,1.3.6.1.5.5.7.48.1".   It says "traverse the XML tree from the caller
    // node and stop at the 1st node having tag = "oid" and content = "1.3.6.1.5.5.7.48.1".
    // The "|" char separates the 1st command from the 2nd.
    // The 2nd command is "++" and says "move to the next sibling".
}