Microsoft C++ Rest SDK for Graph APIs - c++

Question

I am trying out Microsoft's C++ Rest SDK (https://microsoft.github.io/cpprestsdk/index.html) to invoke Graph APIs but it has been a struggle so far.
In C# I can complete my tasks in a few lines of code. For example, refer following code from a Microsoft tutorial:
AuthenticationConfig config = AuthenticationConfig.ReadFromJsonFile("appsettings.json");
bool isUsingClientSecret = AppUsesClientSecret(config);
IConfidentialClientApplication app;
if (isUsingClientSecret)
{
app = ConfidentialClientApplicationBuilder.Create(config.ClientId)
.WithClientSecret(config.ClientSecret)
.WithAuthority(new Uri(config.Authority))
.Build();
}
string[] scopes = new string[] { $"{config.ApiUrl}.default" };
AuthenticationResult result = null;
try
{
result = await app.AcquireTokenForClient(scopes)
.ExecuteAsync();
}
catch (MsalServiceException ex) when (ex.Message.Contains("AADSTS70011"))
{
}
// config.ApiUrl is set to "graph.microft.com"
if (result != null)
{
var httpClient = new HttpClient();
var apiCaller = new ProtectedApiCallHelper(httpClient);
await apiCaller.CallWebApiAndProcessResultASync($"{config.ApiUrl}v1.0/users", result.AccessToken, Display);
}
Now for cross-platform support, I need to develop similar functionality in C++ and for this purpose, we are exploring C++ Rest SDK from Microsoft. But I am unable to find any good examples to achieve a simple thing like providing client ID, client secret to get access token and to authorize.
Please let me know if anyone has come across any example / link to achieve the same.

Answer 1

Here you have some code for oauth 2.0 in Dropbox, Linkedin and MS Live scope:
https://github.com/microsoft/cpprestsdk/blob/master/Release/samples/Oauth2Client/Oauth2Client.cpp
Other samples within C++ Rest SDK:
https://github.com/microsoft/cpprestsdk/tree/master/Release/samples
First of all, you have to distinguish:
1. MS Graph authentication - which is, in fact, Azure Access Directory/Microsoft identity platform authentication, based on oauth 2.0 (short name: MSAL)
2. Accessing the MS Graph API using access token from the authentication process (in the standard process you should use MS Graph SDK)
For the C++ there is no MSAL or SDK library.
So - for authentication, you should use oauth 2.0 example which I pasted above.
Because you need to write everything on your own, please read deeply docs about authentication for MS Graph
https://learn.microsoft.com/en-us/graph/auth/
Here you can watch all the needed endpoints, secrets etc. for sample Postman calls:
https://learn.microsoft.com/en-us/graph/use-postman#set-up-on-behalf-of-api-calls
https://developer.microsoft.com/en-us/graph/blogs/30daysmsgraph-day-13-postman-to-make-microsoft-graph-calls/
In the URLs there are the following variables used:
Callback URL: https://app.getpostman.com/oauth2/callback
Auth URL: https://login.microsoftonline.com/**TENANTID**/oauth2/v2.0/authorize
Access Token URL: https://login.microsoftonline.com/**TENANTID**/oauth2/v2.0/token
Client ID: CLIENTID
Client Secret: CLIENTSECRET
Scope: https://graph.microsoft.com/.default
State: RANDOMSTRING
For the API calls, read about Microsoft Graph REST API v1.0 reference
https://learn.microsoft.com/en-us/graph/api/overview?toc=./ref/toc.json&view=graph-rest-1.0