(PowerBuilder) 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.

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integer li_rc
oleobject loo_Oauth2
string ls_Url
integer li_Success
integer li_NumMsWaited
oleobject loo_Json
oleobject loo_DtExpire
oleobject loo_Fac

// To further clarify, see OAuth 2.0 Authorization Flow

loo_Oauth2 = create oleobject
// Use "Chilkat_9_5_0.OAuth2" for versions of Chilkat < 10.0.0
li_rc = loo_Oauth2.ConnectToNewObject("Chilkat.OAuth2")
if li_rc < 0 then
    destroy loo_Oauth2
    MessageBox("Error","Connecting to COM object failed")
    return
end if

// 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.
loo_Oauth2.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
loo_Oauth2.AuthorizationEndpoint = "https://login.microsoftonline.com/common/oauth2/v2.0/authorize"
loo_Oauth2.TokenEndpoint = "https://login.microsoftonline.com/common/oauth2/v2.0/token"

// Replace these with actual values.
loo_Oauth2.ClientId = "CLIENT_ID"

// This is for Require Proof Key for Code Exchange (PKCE)
// See OAuth2 PKCE Explained
loo_Oauth2.CodeChallenge = 1
loo_Oauth2.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
loo_Oauth2.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.
ls_Url = loo_Oauth2.StartAuth()
if loo_Oauth2.LastMethodSuccess <> 1 then
    Write-Debug loo_Oauth2.LastErrorText
    destroy loo_Oauth2
    return
end if

// Launch the default browser on the system and navigate to the url.
// The LaunchBrowser method was added in Chilkat v10.1.2.
li_Success = loo_Oauth2.LaunchBrowser(ls_Url)
if li_Success = 0 then
    Write-Debug loo_Oauth2.LastErrorText
    destroy loo_Oauth2
    return
end if

// Wait for the user to approve or deny authorization in the browser.
li_NumMsWaited = 0
do while (li_NumMsWaited < 90000) AND (loo_Oauth2.AuthFlowState < 3)
    loo_Oauth2.SleepMs(100)
    li_NumMsWaited = li_NumMsWaited + 100
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.

if loo_Oauth2.AuthFlowState < 3 then
    loo_Oauth2.Cancel()
    Write-Debug "No response from the browser!"
    destroy loo_Oauth2
    return
end if

// 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 loo_Oauth2.AuthFlowState = 5 then
    Write-Debug "OAuth2 failed to complete."
    Write-Debug loo_Oauth2.FailureInfo
    destroy loo_Oauth2
    return
end if

if loo_Oauth2.AuthFlowState = 4 then
    Write-Debug "OAuth2 authorization was denied."
    Write-Debug loo_Oauth2.AccessTokenResponse
    destroy loo_Oauth2
    return
end if

if loo_Oauth2.AuthFlowState <> 3 then
    Write-Debug "Unexpected AuthFlowState:" + string(loo_Oauth2.AuthFlowState)
    destroy loo_Oauth2
    return
end if

Write-Debug "OAuth2 authorization granted!"
Write-Debug "Access Token = " + loo_Oauth2.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:
loo_Json = create oleobject
// Use "Chilkat_9_5_0.JsonObject" for versions of Chilkat < 10.0.0
li_rc = loo_Json.ConnectToNewObject("Chilkat.JsonObject")

loo_Json.Load(loo_Oauth2.AccessTokenResponse)
loo_Json.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 loo_Json.HasMember("expires_on") <> 1 then
    loo_DtExpire = create oleobject
    // Use "Chilkat_9_5_0.CkDateTime" for versions of Chilkat < 10.0.0
    li_rc = loo_DtExpire.ConnectToNewObject("Chilkat.CkDateTime")

    loo_DtExpire.SetFromCurrentSystemTime()
    loo_DtExpire.AddSeconds(loo_Json.IntOf("expires_in"))
    loo_Json.AppendString("expires_on",loo_DtExpire.GetAsUnixTimeStr(0))
end if

Write-Debug loo_Json.Emit()

// Save the JSON to a file for future requests.
loo_Fac = create oleobject
// Use "Chilkat_9_5_0.FileAccess" for versions of Chilkat < 10.0.0
li_rc = loo_Fac.ConnectToNewObject("Chilkat.FileAccess")

loo_Fac.WriteEntireTextFile("qa_data/tokens/_myAzureApp.json",loo_Json.Emit(),"utf-8",0)

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


destroy loo_Oauth2
destroy loo_Json
destroy loo_DtExpire
destroy loo_Fac