Visual FoxPro

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: Visual FoxPro

LOCAL lnSuccess
LOCAL loOauth2
LOCAL lcUrl
LOCAL lnNumMsWaited
LOCAL loJson
LOCAL loFac

lnSuccess = 0

*  This example requires the Chilkat API to have been previously unlocked.
*  See Global Unlock Sample for sample code.

loOauth2 = CreateObject('Chilkat.OAuth2')

*  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.
loOauth2.ListenPort = 3017

loOauth2.AuthorizationEndpoint = "https://{yourOktaDomain}/oauth2/default/v1/authorize"
loOauth2.TokenEndpoint = "https://{yourOktaDomain}/oauth2/default/v1/token"

*  Replace these with actual values.
loOauth2.ClientId = "OKTA_CLIENT_ID"
loOauth2.ClientSecret = "OKTA_CLIENT_SECRET"

loOauth2.CodeChallenge = 1
loOauth2.IncludeNonce = 1

*  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.
loOauth2.Scope = "openid offline_access"

*  Begin the OAuth2 three-legged flow.  This returns a URL that should be loaded in a browser.
lcUrl = loOauth2.StartAuth()
IF (loOauth2.LastMethodSuccess = 0) THEN
    ? loOauth2.LastErrorText
    RELEASE loOauth2
    CANCEL
ENDIF

? "URL to load in browser: " + lcUrl

*  Launch the system's default browser navigated to the URL.
lnSuccess = loOauth2.LaunchBrowser(lcUrl)
IF (lnSuccess = 0) THEN
    ? loOauth2.LastErrorText
    RELEASE loOauth2
    CANCEL
ENDIF

*  Now wait for the authorization.
*  We'll wait for a max of 60 seconds.
lnNumMsWaited = 0
DO WHILE (lnNumMsWaited < 60000) AND (loOauth2.AuthFlowState < 3)
    loOauth2.SleepMs(100)
    lnNumMsWaited = lnNumMsWaited + 100
ENDDO

*  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 (loOauth2.AuthFlowState < 3) THEN
    loOauth2.Cancel()
    ? "No response from the browser!"
    RELEASE loOauth2
    CANCEL
ENDIF

*  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 (loOauth2.AuthFlowState = 5) THEN
    ? "OAuth2 failed to complete."
    ? loOauth2.FailureInfo
    RELEASE loOauth2
    CANCEL
ENDIF

IF (loOauth2.AuthFlowState = 4) THEN
    ? "OAuth2 authorization was denied."
    ? loOauth2.AccessTokenResponse
    RELEASE loOauth2
    CANCEL
ENDIF

IF (loOauth2.AuthFlowState <> 3) THEN
    ? "Unexpected AuthFlowState:" + STR(loOauth2.AuthFlowState)
    RELEASE loOauth2
    CANCEL
ENDIF

? "OAuth2 authorization granted!"
? "Access Token = " + loOauth2.AccessToken

*  Get the full JSON response:
loJson = CreateObject('Chilkat.JsonObject')
loJson.Load(loOauth2.AccessTokenResponse)
loJson.EmitCompact = 0
? loJson.Emit()

*  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.
loFac = CreateObject('Chilkat.FileAccess')
loFac.WriteEntireTextFile("qa_data/tokens/okta.json",loJson.Emit(),"utf-8",0)

RELEASE loOauth2
RELEASE loJson
RELEASE loFac