Delphi ActiveX Requires Chilkat v10.1.2+
Dynamics CRM OAuth2 Access Token

Demonstrates how to get a Microsoft Dynamics CRM OAuth2 access token from a desktop (installed) application or script.
Chilkat Delphi ActiveX Downloads

Delphi ActiveX
var
success: Integer;
oauth2: TChilkatOAuth2;
url: WideString;
http: TChilkatHttp;
sbPreCheck: TChilkatStringBuilder;
numMsWaited: Integer;
json: TChilkatJsonObject;
dtExpire: TCkDateTime;
fac: TCkFileAccess;

begin
success := 0;

//  To further clarify, see OAuth 2.0 Authorization Flow

oauth2 := TChilkatOAuth2.Create(Self);

//  This should be the port in the localhost redirect URL for your app.
//  Important: Make sure the redirect URI in your Azure app registration 
//  is exactly "http://localhost:3017/".  Don't forget the ending "/" char.
//  The redirect URL would look like "http://localhost:3017/" if the port number is 3017.
oauth2.ListenPort := 3017;

//  Get the endpoints from the Azure Portal in the "endpoints" section of App Registrations..
//  The DYNAMICS-ENDPOINT-GUID is a Tenant dynamics-endpoint-guid  such as 1b54e7ee-d61b-4f12-a621-a6b2805b98c2
oauth2.AuthorizationEndpoint := 'https://login.microsoftonline.com/DYNAMICS-ENDPOINT-GUID/oauth2/authorize';
oauth2.TokenEndpoint := 'https://login.microsoftonline.com/DYNAMICS-ENDPOINT-GUID/oauth2/token';

//  Replace these with actual values.
oauth2.ClientId := 'DYNAMICS-CRM-CLIENT-ID';
oauth2.ClientSecret := 'DYNAMICS-CRM-SECRET-KEY';

oauth2.Resource := 'https://mydynamicsdomain.api.crm.dynamics.com';

oauth2.RedirectAllowHtml := '<html><body><p>Thank you for granting access.</p></bod></html>';
oauth2.RedirectDenyHtml := '<html><body><p>Maybe next time...</p></bod></html>';

//  Begin the OAuth2 Authorization code flow.  This returns a URL that should be loaded in a browser.
url := oauth2.StartAuth();
if (oauth2.LastMethodSuccess <> 1) then
  begin
    Memo1.Lines.Add(oauth2.LastErrorText);
    Exit;
  end;

//  We can pre-check the URL by sending a GET to catch any up-front errors.
//  If we receive JSON with an error in response, then we don't proceed any farther.

//  If we receive an HTML response, and the response status = 200, then all should be OK.
//  We can proceed by displaying an interactive browser loaded with the url.
http := TChilkatHttp.Create(Self);
sbPreCheck := TChilkatStringBuilder.Create(Self);
success := http.QuickGetSb(url,sbPreCheck.ControlInterface);
if ((http.LastStatus <> 200) or (sbPreCheck.StartsWith('{',1) <> 1)) then
  begin
    Memo1.Lines.Add('JSON Error Response:');
    Memo1.Lines.Add(sbPreCheck.GetAsString());
    Exit;
  end;
//  If the HTTP request itself failed, then examine the error.
if (success = 0) then
  begin
    Memo1.Lines.Add(http.LastErrorText);
    Exit;
  end;
//  OK.. the pre-flight check seems OK, go ahead with getting the interactive user authorization..

//  Launch the default browser on the system and navigate to the url.
//  The LaunchBrowser method was added in Chilkat v10.1.2.
success := oauth2.LaunchBrowser(url);
if (success = 0) then
  begin
    Memo1.Lines.Add(oauth2.LastErrorText);
    Exit;
  end;

//  Wait for the user to approve or deny authorization in the browser.
numMsWaited := 0;
while (numMsWaited < 90000) and (oauth2.AuthFlowState < 3) do
  begin
    oauth2.SleepMs(100);
    numMsWaited := numMsWaited + 100;
  end;

//  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 (oauth2.AuthFlowState < 3) then
  begin
    oauth2.Cancel();
    Memo1.Lines.Add('No response from the browser!');
    Exit;
  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.

if (oauth2.AuthFlowState = 5) then
  begin
    Memo1.Lines.Add('OAuth2 failed to complete.');
    Memo1.Lines.Add(oauth2.FailureInfo);
    Exit;
  end;

if (oauth2.AuthFlowState = 4) then
  begin
    Memo1.Lines.Add('OAuth2 authorization was denied.');
    Memo1.Lines.Add(oauth2.AccessTokenResponse);
    Exit;
  end;

if (oauth2.AuthFlowState <> 3) then
  begin
    Memo1.Lines.Add('Unexpected AuthFlowState:' + IntToStr(oauth2.AuthFlowState));
    Exit;
  end;

Memo1.Lines.Add('OAuth2 authorization granted!');
Memo1.Lines.Add('Access Token = ' + oauth2.AccessToken);

//  Get the full JSON response:
json := TChilkatJsonObject.Create(Self);
json.Load(oauth2.AccessTokenResponse);
json.EmitCompact := 0;

//  The JSON response looks like this:

//  {
//    "token_type": "Bearer",
//    "scope": "user_impersonation",
//    "expires_in": "3599",
//    "ext_expires_in": "0",
//    "expires_on": "1524783438",
//    "not_before": "1524779538",
//    "resource": "https://mydomain.api.crm.dynamics.com",
//    "access_token": "...",
//    "refresh_token": "...",
//    "id_token": "..."
//  }

//  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 (json.HasMember('expires_on') <> 1) then
  begin
    dtExpire := TCkDateTime.Create(Self);
    dtExpire.SetFromCurrentSystemTime();
    dtExpire.AddSeconds(json.IntOf('expires_in'));
    json.AppendString('expires_on',dtExpire.GetAsUnixTimeStr(0));
  end;

Memo1.Lines.Add(json.Emit());

//  Save the JSON to a file for future requests.
fac := TCkFileAccess.Create(Self);
fac.WriteEntireTextFile('qa_data/tokens/dynamicsCrm.json',json.Emit(),'utf-8',0);