(PureBasic) Microsoft Teams OAuth2 Access Token

Gets an access token on behalf of a user. This is example code for desktop applications for getting an OAuth2 access token. You'll need to make a minor edit to the code as described in the comments to launch a browser to browse to a URL. The account owner will interactively grant or deny access, and after doing so, the example code continues to exchange the grant code for an access token. Once the initial access token is obtained, it can be repeatedly refreshed without user interaction.

For more information, see https://docs.microsoft.com/en-us/graph/auth/auth-concepts

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/v2.0/authorize")
    CkOAuth2::setCkTokenEndpoint(oauth2, "https://login.microsoftonline.com/common/oauth2/v2.0/token")

    ; Replace these with actual values.
    CkOAuth2::setCkClientId(oauth2, "MICROSOFT-GRAPH-CLIENT-ID")
    ; This is your app password:
    CkOAuth2::setCkClientSecret(oauth2, "MICROSOFT-GRAPH-CLIENT-SECRET")

    CkOAuth2::setCkCodeChallenge(oauth2, 0)
    ; Provide a SPACE separated list of scopes.
    ; See https://docs.microsoft.com/en-us/graph/permissions-reference#teams-permissions

    ; Important: To get a refresh token in the final response, you must include the "offline_access" scope
    ; For testing purposes, this example requests more scopes than are likely need.
    CkOAuth2::setCkScope(oauth2, "openid profile offline_access user.readwrite team.create directory.readwrite.all Group.ReadWrite.All TeamMember.ReadWrite.All")

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

    ; {
    ;   "token_type": "Bearer",
    ;   "scope": "openid profile User.ReadWrite Notes.ReadWrite Notes.Create User.Read Mail.Send Mail.ReadWrite Files.ReadWrite Calendars.ReadWrite Group.ReadWrite.All",
    ;   "expires_in": 3600,
    ;   "ext_expires_in": 3600,
    ;   "access_token": "...",
    ;   "refresh_token": "...",
    ;   "id_token": "..."
    ; }

    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/microsoft_teams.json",CkJsonObject::ckEmit(json),"utf-8",0)


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


    ProcedureReturn
EndProcedure