(DataFlex) 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.

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

Use ChilkatAx-win32.pkg

Procedure Test
    Handle hoOauth2
    String sUrl
    Boolean iSuccess
    Integer iNumMsWaited
    Handle hoJson
    Handle hoDtExpire
    Handle hoFac
    String sTemp1
    Integer iTemp1
    Boolean bTemp1

    // To further clarify, see OAuth 2.0 Authorization Flow

    Get Create (RefClass(cComChilkatOAuth2)) To hoOauth2
    If (Not(IsComObjectCreated(hoOauth2))) Begin
        Send CreateComObject of hoOauth2
    End

    // 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.
    Set ComListenPort Of hoOauth2 To 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
    Set ComAuthorizationEndpoint Of hoOauth2 To "https://login.microsoftonline.com/common/oauth2/v2.0/authorize"
    Set ComTokenEndpoint Of hoOauth2 To "https://login.microsoftonline.com/common/oauth2/v2.0/token"

    // Replace these with actual values.
    Set ComClientId Of hoOauth2 To "CLIENT_ID"

    // This is for Require Proof Key for Code Exchange (PKCE)
    // See OAuth2 PKCE Explained
    Set ComCodeChallenge Of hoOauth2 To True
    Set ComCodeChallengeMethod Of hoOauth2 To "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
    Set ComScope Of hoOauth2 To "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.
    Get ComStartAuth Of hoOauth2 To sUrl
    Get ComLastMethodSuccess Of hoOauth2 To bTemp1
    If (bTemp1 <> True) Begin
        Get ComLastErrorText Of hoOauth2 To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Launch the default browser on the system and navigate to the url.
    // The LaunchBrowser method was added in Chilkat v10.1.2.
    Get ComLaunchBrowser Of hoOauth2 sUrl To iSuccess
    If (iSuccess = False) Begin
        Get ComLastErrorText Of hoOauth2 To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // Wait for the user to approve or deny authorization in the browser.
    Move 0 To iNumMsWaited
    While ((iNumMsWaited < 90000) And ((ComAuthFlowState(hoOauth2)) < 3))
        Send ComSleepMs To hoOauth2 100
        Move (iNumMsWaited + 100) To iNumMsWaited
    Loop

    // 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.

    Get ComAuthFlowState Of hoOauth2 To iTemp1
    If (iTemp1 < 3) Begin
        Get ComCancel Of hoOauth2 To iSuccess
        Showln "No response from the browser!"
        Procedure_Return
    End

    // 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.

    Get ComAuthFlowState Of hoOauth2 To iTemp1
    If (iTemp1 = 5) Begin
        Showln "OAuth2 failed to complete."
        Get ComFailureInfo Of hoOauth2 To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get ComAuthFlowState Of hoOauth2 To iTemp1
    If (iTemp1 = 4) Begin
        Showln "OAuth2 authorization was denied."
        Get ComAccessTokenResponse Of hoOauth2 To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get ComAuthFlowState Of hoOauth2 To iTemp1
    If (iTemp1 <> 3) Begin
        Get ComAuthFlowState Of hoOauth2 To iTemp1
        Showln "Unexpected AuthFlowState:" iTemp1
        Procedure_Return
    End

    Showln "OAuth2 authorization granted!"
    Get ComAccessToken Of hoOauth2 To sTemp1
    Showln "Access Token = " sTemp1

    // 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:
    Get Create (RefClass(cComChilkatJsonObject)) To hoJson
    If (Not(IsComObjectCreated(hoJson))) Begin
        Send CreateComObject of hoJson
    End
    Get ComAccessTokenResponse Of hoOauth2 To sTemp1
    Get ComLoad Of hoJson sTemp1 To iSuccess
    Set ComEmitCompact Of hoJson To False

    // 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.
    Get ComHasMember Of hoJson "expires_on" To bTemp1
    If (bTemp1 <> True) Begin
        Get Create (RefClass(cComCkDateTime)) To hoDtExpire
        If (Not(IsComObjectCreated(hoDtExpire))) Begin
            Send CreateComObject of hoDtExpire
        End
        Get ComSetFromCurrentSystemTime Of hoDtExpire To iSuccess
        Get ComIntOf Of hoJson "expires_in" To iTemp1
        Get ComAddSeconds Of hoDtExpire iTemp1 To iSuccess
        Get ComGetAsUnixTimeStr Of hoDtExpire False To sTemp1
        Get ComAppendString Of hoJson "expires_on" sTemp1 To iSuccess
    End

    Get ComEmit Of hoJson To sTemp1
    Showln sTemp1

    // Save the JSON to a file for future requests.
    Get Create (RefClass(cComCkFileAccess)) To hoFac
    If (Not(IsComObjectCreated(hoFac))) Begin
        Send CreateComObject of hoFac
    End
    Get ComEmit Of hoJson To sTemp1
    Get ComWriteEntireTextFile Of hoFac "qa_data/tokens/_myAzureApp.json" sTemp1 "utf-8" False To iSuccess

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


End_Procedure