Xbase++

Get OAuth2 Access Token for Azure Registered App

Demonstrates how to get OAuth2 access token for an Azure Registered App from a desktop application or script. This example demonstrates the OAuth2 authorization flow.

This example requires Chilkat v10.1.2 or greater.

Xbase++

LOCAL nSuccess
LOCAL oOauth2
LOCAL cUrl
LOCAL nNumMsWaited
LOCAL oJson
LOCAL oDtExpire
LOCAL oFac

nSuccess := 0

//  To further clarify, see OAuth 2.0 Authorization Flow

oOauth2 := CreateObject("Chilkat.OAuth2")

//  This should be the port in the localhost callback URL for your app.  
//  The callback URL would look like "http://localhost:3017/" if the port number is 3017.
oOauth2:ListenPort := 3017

//  ----------------------------------------------------------------------------------------------------------
//  The screenshot at the bottom of this page shows how we created the Azure App Registration for this example.
//  ----------------------------------------------------------------------------------------------------------

//  Note: The endpoint depends on the Azure App Registration.
//  See How to Choose the Correct Endpoints for your Azure App Registration
oOauth2:AuthorizationEndpoint := "https://login.microsoftonline.com/common/oauth2/v2.0/authorize"
oOauth2:TokenEndpoint := "https://login.microsoftonline.com/common/oauth2/v2.0/token"

//  Replace these with actual values.
oOauth2:ClientId := "CLIENT_ID"

//  This is for Require Proof Key for Code Exchange (PKCE)
//  See OAuth2 PKCE Explained
oOauth2:CodeChallenge := 1
oOauth2:CodeChallengeMethod := "S256"

//  Provide a SPACE separated list of scopes.
//  See https://developer.microsoft.com/en-us/graph/docs/authorization/permission_scopes 

//  Important: To get a refresh token in the final response, ask for "offline_access" scope
oOauth2:Scope := "openid profile offline_access user.readwrite mail.readwrite mail.send files.readwrite"

//  Begin the OAuth2 three-legged flow.  This returns a URL that should be loaded in a browser.
cUrl := oOauth2:StartAuth()
IF (oOauth2:LastMethodSuccess != 1)
    ? oOauth2:LastErrorText
    oOauth2:destroy()
    RETURN
ENDIF

//  Launch the default browser on the system and navigate to the url.
//  The LaunchBrowser method was added in Chilkat v10.1.2.
nSuccess := oOauth2:LaunchBrowser(cUrl)
IF (nSuccess == 0)
    ? oOauth2:LastErrorText
    oOauth2:destroy()
    RETURN
ENDIF

//  Wait for the user to approve or deny authorization in the browser.
nNumMsWaited := 0
DO WHILE (nNumMsWaited < 90000) .AND. (oOauth2:AuthFlowState < 3)
    oOauth2:SleepMs(100)
    nNumMsWaited := nNumMsWaited + 100
ENDDO

//  If the browser does not respond within the specified time, AuthFlowState will be:
//  
//  1: Waiting for Redirect � The OAuth2 background thread is waiting for the browser's redirect request.
//  2: Waiting for Final Response � The thread is awaiting the final access token response.
//  In either case, cancel the background task initiated by StartAuth.

IF (oOauth2:AuthFlowState < 3)
    oOauth2:Cancel()
    ? "No response from the browser!"
    oOauth2:destroy()
    RETURN
ENDIF

//  Check AuthFlowState to determine if authorization was granted, denied, or failed:
//  
//  3: Success � OAuth2 flow completed, the background thread exited, and the successful response is in AccessTokenResponse.
//  4: Access Denied � OAuth2 flow completed, the background thread exited, and the error response is in AccessTokenResponse.
//  5: Failure � OAuth2 flow failed before completion, the background thread exited, and error details are in FailureInfo.

IF (oOauth2:AuthFlowState == 5)
    ? "OAuth2 failed to complete."
    ? oOauth2:FailureInfo
    oOauth2:destroy()
    RETURN
ENDIF

IF (oOauth2:AuthFlowState == 4)
    ? "OAuth2 authorization was denied."
    ? oOauth2:AccessTokenResponse
    oOauth2:destroy()
    RETURN
ENDIF

IF (oOauth2:AuthFlowState != 3)
    ? "Unexpected AuthFlowState:" + Str(oOauth2:AuthFlowState)
    oOauth2:destroy()
    RETURN
ENDIF

? "OAuth2 authorization granted!"
? "Access Token = " + oOauth2:AccessToken

//  When the token is near expiration, your app can refresh as shown here:
//  Refresh Expiring OAuth2 Access Token for Azure Registered App

//  Get the full JSON response:
oJson := CreateObject("Chilkat.JsonObject")
oJson:Load(oOauth2:AccessTokenResponse)
oJson:EmitCompact := 0

//  The JSON response looks like this:

//  {
//    "token_type": "Bearer",
//    "scope": "User.Read Mail.ReadWrite Mail.Send",
//    "expires_in": 3600,
//    "ext_expires_in": 0,
//    "access_token": "EwBAA8l6B...",
//    "refresh_token": "MCRMdbe...",
//    "id_token": "eyJ0eXA..."
//  }

//  If an "expires_on" member does not exist, then add the JSON member by
//  getting the current system date/time and adding the "expires_in" seconds.
//  This way we'll know when the token expires.
IF (oJson:HasMember("expires_on") != 1)
    oDtExpire := CreateObject("Chilkat.CkDateTime")
    oDtExpire:SetFromCurrentSystemTime()
    oDtExpire:AddSeconds(oJson:IntOf("expires_in"))
    oJson:AppendString("expires_on", oDtExpire:GetAsUnixTimeStr(0))
ENDIF

? oJson:Emit()

//  Save the JSON to a file for future requests.
oFac := CreateObject("Chilkat.FileAccess")
oFac:WriteEntireTextFile("qa_data/tokens/_myAzureApp.json", oJson:Emit(), "utf-8", 0)

//  This is a screenshot of how we created the Azure App for this example:
//  

oOauth2:destroy()
oJson:destroy()
oDtExpire:destroy()
oFac:destroy()