Validate a JWS with a Public Key

See more JSON Web Signatures (JWS) Examples

Demonstrates Jws.SetPublicKey, which sets the public key used to validate a signature of a loaded JWS.

The file path is relative to the application's current working directory. An absolute path may also be used. Supply the path appropriate to your own environment.

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

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

    const jws = try chilkat.Jws.init();
    defer jws.deinit();

    // Load the JWS compact serialization.
    const jws_compact = "eyJhbGciOiJIUzI1NiJ9.VGhpcyBpcyB0aGUgY29udGVudCB0byBzaWduLg.<signature>";
    jws.loadJws(jws_compact) catch {
        std.debug.print("{s}\n", .{try jws.getLastErrorText(alloc)});
        return;
    };

    // The file path is relative to the application's current working directory.  An absolute path
    // may also be used.  Supply the path appropriate to your own environment.
    // Load the signer's public key and set it for validating signature 0.
    const pub_key = try chilkat.PublicKey.init();
    defer pub_key.deinit();
    pub_key.loadFromFile("qa_data/signer_pubkey.pem") catch {
        std.debug.print("{s}\n", .{try pub_key.getLastErrorText(alloc)});
        return;
    };

    jws.setPublicKey(0, pub_key) catch {
        std.debug.print("{s}\n", .{try jws.getLastErrorText(alloc)});
        return;
    };

    // Validate the signature.  Validate returns 1 when valid, 0 when not, or a negative value on error.
    const v = jws.validate(0);
    if (v < 0) {
        std.debug.print("{s}\n", .{try jws.getLastErrorText(alloc)});
        return;
    }

    if (v != 1) {
        std.debug.print("The signature is not valid.\n", .{});
        return;
    }

    std.debug.print("The signature is valid.\n", .{});
}