Zig

Authorization Code Flow with PKCE for Native Apps

See more Okta OAuth/OIDC Examples

Demonstrates the authorization code flow with Proof Key for Code Exchange (PKCE) for native apps. In Okta, your app should be defined as shown: 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.

    const oauth2 = try chilkat.OAuth2.init();
    defer oauth2.deinit();

    // This should be the port in the Login redirect URI for your app.
    // Your app's Login redirect URI should be "http://localhost:3017/" if the port number is 3017.
    oauth2.setListenPort(3017);

    oauth2.setAuthorizationEndpoint("https://{yourOktaDomain}/oauth2/default/v1/authorize");
    oauth2.setTokenEndpoint("https://{yourOktaDomain}/oauth2/default/v1/token");

    // Replace these with actual values.
    oauth2.setClientId("OKTA_CLIENT_ID");
    oauth2.setClientSecret("OKTA_CLIENT_SECRET");

    oauth2.setCodeChallenge(true);
    oauth2.setIncludeNonce(true);

    // Make sure to include "offline_access" to get a refresh token included in the final JSON response.
    // Add any additional needed scopes separated by space chars.
    oauth2.setScope("openid offline_access");

    // Begin the OAuth2 three-legged flow.  This returns a URL that should be loaded in a browser.
    const url = oauth2.startAuth(alloc) catch {
        std.debug.print("{s}\n", .{try oauth2.getLastErrorText(alloc)});
        return;
    };

    std.debug.print("URL to load in browser: {s}\n", .{url});

    // Launch the system's default browser navigated to the URL.
    oauth2.launchBrowser(url) catch {
        std.debug.print("{s}\n", .{try oauth2.getLastErrorText(alloc)});
        return;
    };

    // Now wait for the authorization.
    // We'll wait for a max of 60 seconds.
    var num_ms_waited: i32 = 0;
    while ((num_ms_waited < 60000) and (oauth2.getAuthFlowState() < 3)) {
        oauth2.sleepMs(100);
        num_ms_waited = num_ms_waited + 100;
    }

    // If there was no response from the browser within 30 seconds, then
    // the AuthFlowState will be equal to 1 or 2.
    // 1: Waiting for Redirect. The OAuth2 background thread is waiting to receive the redirect HTTP request from the browser.
    // 2: Waiting for Final Response. The OAuth2 background thread is waiting for the final access token response.
    // In that case, cancel the background task started in the call to StartAuth.
    if (oauth2.getAuthFlowState() < 3) {
        oauth2.cancel() catch {};
        std.debug.print("No response from the browser!\n", .{});
        return;
    }

    // Check the AuthFlowState to see if authorization was granted, denied, or if some error occurred
    // The possible AuthFlowState values are:
    // 3: Completed with Success. The OAuth2 flow has completed, the background thread exited, and the successful JSON response is available in AccessTokenResponse property.
    // 4: Completed with Access Denied. The OAuth2 flow has completed, the background thread exited, and the error JSON is available in AccessTokenResponse property.
    // 5: Failed Prior to Completion. The OAuth2 flow failed to complete, the background thread exited, and the error information is available in the FailureInfo property.
    if (oauth2.getAuthFlowState() == 5) {
        std.debug.print("OAuth2 failed to complete.\n", .{});
        std.debug.print("{s}\n", .{try oauth2.getFailureInfo(alloc)});
        return;
    }

    if (oauth2.getAuthFlowState() == 4) {
        std.debug.print("OAuth2 authorization was denied.\n", .{});
        std.debug.print("{s}\n", .{try oauth2.getAccessTokenResponse(alloc)});
        return;
    }

    if (oauth2.getAuthFlowState() != 3) {
        std.debug.print("Unexpected AuthFlowState:{d}\n", .{oauth2.getAuthFlowState()});
        return;
    }

    std.debug.print("OAuth2 authorization granted!\n", .{});
    std.debug.print("Access Token = {s}\n", .{try oauth2.getAccessToken(alloc)});

    // Get the full JSON response:
    const json = try chilkat.JsonObject.init();
    defer json.deinit();
    json.load(try oauth2.getAccessTokenResponse(alloc)) catch {};
    json.setEmitCompact(false);
    std.debug.print("{s}\n", .{try json.emit(alloc)});

    // The JSON response looks like this:

    // {
    //   "access_token": "eyJraWQi ... Kn4IiEfOw",
    //   "token_type": "Bearer",
    //   "expires_in": 3600,
    //   "scope": "offline_access openid",
    //   "refresh_token": "0jCqotuuUegdjNzB9uuSsfGM2Cu5HnCHUxoJ0yhZ4rs",
    //   "id_token": "eyJraWQiO ... 09WGEq3dTRmQF86PzJg"
    // }

    // Save the JSON to a file for future requests.
    const fac = try chilkat.FileAccess.init();
    defer fac.deinit();
    fac.writeEntireTextFile("qa_data/tokens/okta.json", try json.emit(alloc), "utf-8", false) catch {};
}