(PureBasic) Microsoft Graph OAuth2 App Authentication using Azure AD

Demonstrates how to get a Microsoft Graph OAuth2 access token from a desktop application or script.

The Microsoft Graph supports two authentication providers:

• To authenticate users with personal Microsoft accounts, such as live.com or outlook.com accounts, use the Azure Active Directory (Azure AD) v2.0 endpoint.
• To authenticate users with enterprise (that is, work or school) accounts, use Azure AD.

This example uses the Azure AD endpoint (for enterprise accounts).

This example requires Chilkat v9.5.0.67 or greater.

Chilkat PureBasic Module Download Chilkat PureBasic Module

IncludeFile "CkFileAccess.pb"
IncludeFile "CkJsonObject.pb"
IncludeFile "CkOAuth2.pb"

Procedure ChilkatExample()

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

    oauth2.i = CkOAuth2::ckCreate()
    If oauth2.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success.i

    ; 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.
    CkOAuth2::setCkListenPort(oauth2, 3017)

    CkOAuth2::setCkAuthorizationEndpoint(oauth2, "https://login.microsoftonline.com/common/oauth2/authorize")
    CkOAuth2::setCkTokenEndpoint(oauth2, "https://login.microsoftonline.com/common/oauth2/token")

    ; -----------------------------------------------------------------------------
    ; Important: Notice that the above endpoints are the "Azure AD" endpoints, not
    ; the "Azure AD v2.0" endpoints.  The 2.0 endpoints are very similar. They are:
    ; https://login.microsoftonline.com/common/oauth2/v2.0/authorize
    ; and
    ; https://login.microsoftonline.com/common/oauth2/v2.0/token
    ; Pay close attention to the endpoints to make sure they match what you want.
    ; -----------------------------------------------------------------------------

    ; Replace these with actual values.
    CkOAuth2::setCkClientId(oauth2, "MY_AZURE_AD_APP_ID")
    ; This is your app key/password/client secret:
    CkOAuth2::setCkClientSecret(oauth2, "MY_AZURE_AD_APP_KEY")

    CkOAuth2::setCkCodeChallenge(oauth2, 0)

    ; -----------------------------------------------------------
    ; Important difference between "Azure AD" and "Azure AD v2.0"
    ; 
    ; When using the Azure AD v2.0, endpoints (for personal accounts), the desired
    ; scopes are selected by setting the OAuth2 Scope property here.
    ; However, when using the "Azure AD" endpoints, we DO NOT set the Scope here,
    ; but instead set the OAuth2 Resource property, as shown here:

    CkOAuth2::setCkResource(oauth2, "https://graph.microsoft.com/")

    ; When using the "Azure AD" endpoint, the access token we receive will automatically
    ; be for the scopes matching the permissions granted for the app during the app's registration.

    ; Begin the OAuth2 three-legged flow.  This returns a URL that should be loaded in a browser.
    url.s = CkOAuth2::ckStartAuth(oauth2)
    If CkOAuth2::ckLastMethodSuccess(oauth2) <> 1
        Debug CkOAuth2::ckLastErrorText(oauth2)
        CkOAuth2::ckDispose(oauth2)
        ProcedureReturn
    EndIf

    ; At this point, your application should load the URL in a browser.
    ; For example, 
    ; in C#: System.Diagnostics.Process.Start(url);
    ; in Java: Desktop.getDesktop().browse(new URI(url));
    ; in VBScript: Set wsh=WScript.CreateObject("WScript.Shell")
    ;              wsh.Run url
    ; in Xojo: ShowURL(url)  (see http://docs.xojo.com/index.php/ShowURL)
    ; in Dataflex: Runprogram Background "c:\Program Files\Internet Explorer\iexplore.exe" sUrl        
    ; The Microsoft account owner would interactively accept or deny the authorization request.

    ; Add the code to load the url in a web browser here...

    ; Now wait for the authorization.
    ; We'll wait for a max of 30 seconds.
    numMsWaited.i = 0
    While (numMsWaited < 30000) AND (CkOAuth2::ckAuthFlowState(oauth2) < 3)
        CkOAuth2::ckSleepMs(oauth2,100)
        numMsWaited = numMsWaited + 100
    Wend

    ; 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 CkOAuth2::ckAuthFlowState(oauth2) < 3
        CkOAuth2::ckCancel(oauth2)
        Debug "No response from the browser!"
        CkOAuth2::ckDispose(oauth2)
        ProcedureReturn
    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 CkOAuth2::ckAuthFlowState(oauth2) = 5
        Debug "OAuth2 failed to complete."
        Debug CkOAuth2::ckFailureInfo(oauth2)
        CkOAuth2::ckDispose(oauth2)
        ProcedureReturn
    EndIf

    If CkOAuth2::ckAuthFlowState(oauth2) = 4
        Debug "OAuth2 authorization was denied."
        Debug CkOAuth2::ckAccessTokenResponse(oauth2)
        CkOAuth2::ckDispose(oauth2)
        ProcedureReturn
    EndIf

    If CkOAuth2::ckAuthFlowState(oauth2) <> 3
        Debug "Unexpected AuthFlowState:" + Str(CkOAuth2::ckAuthFlowState(oauth2))
        CkOAuth2::ckDispose(oauth2)
        ProcedureReturn
    EndIf

    Debug "OAuth2 authorization granted!"
    Debug "Access Token = " + CkOAuth2::ckAccessToken(oauth2)

    ; Get the full JSON response:
    json.i = CkJsonObject::ckCreate()
    If json.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkJsonObject::ckLoad(json,CkOAuth2::ckAccessTokenResponse(oauth2))
    CkJsonObject::setCkEmitCompact(json, 0)

    ; The JSON response looks like this:
    ; (Note: The scope property value should match the permissions granted for the app during the app's registration.)

    ; {
    ;     "token_type":"Bearer",
    ;     "scope": "Calendar.ReadWrite Directory.Read.All Files.ReadWrite Group.ReadWrite.All Mail.ReadWrite Mail.Send User.ReadBasic.All",
    ;     "expires_in":"3599",
    ;     "ext_expires_in": "0",
    ;     "expires_on":"1426551729",
    ;     "not_before":"1426547829",
    ;     "resource":"https://graph.microsoft.com/",
    ;     "access_token":"eyJ0eXAiOiJKV1QiLCJhb...",
    ;     "refresh_token":"AAABAAAAvPM1KaPlrEqd...",
    ;     "id_token":"eyJ0eXAiOiJKV1QiLCJhbGci..."
    ; }

    Debug CkJsonObject::ckEmit(json)

    ; Save the JSON to a file for future requests.
    fac.i = CkFileAccess::ckCreate()
    If fac.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkFileAccess::ckWriteEntireTextFile(fac,"qa_data/tokens/microsoftGraphAzureAD.json",CkJsonObject::ckEmit(json),"utf-8",0)


    CkOAuth2::ckDispose(oauth2)
    CkJsonObject::ckDispose(json)
    CkFileAccess::ckDispose(fac)


    ProcedureReturn
EndProcedure