(C++) Get Access Token for Google Tasks using Service Account JSON Key

Demonstrates how to get an access token for the Google Tasks API using a Service Account JSON key.

Chilkat C/C++ Library Downloads
MS Visual C/C++ Linux/CentOS C/C++ Alpine Linux C/C++ MAC OS X C/C++	armhf/aarch64 C/C++ C++ Builder iOS C/C++ Android C/C++	Solaris C/C++ MinGW C/C++

#include <CkFileAccess.h>
#include <CkAuthGoogle.h>
#include <CkSocket.h>

void ChilkatSample(void)
    {
    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    // First load the JSON key into a string.
    CkFileAccess fac;
    const char *jsonKey = fac.readEntireTextFile("qa_data/googleSvcAccountKeys/ChilkatCloud-48f7737c7505.json","utf-8");
    if (fac.get_LastMethodSuccess() != true) {
        std::cout << fac.lastErrorText() << "\r\n";
        return;
    }

    // A JSON private key should look like this:

    // {
    //   "type": "service_account",
    //   "project_id": "chilkatcloud",
    //   "private_key_id": "48f7737c7505bb88eee6a20d09993e10605d466e",
    //   "private_key": "-----BEGIN PRIVATE KEY----- ... -----END PRIVATE KEY-----\n",
    //   "client_email": "pip-564@chilkatcloud.iam.gserviceaccount.com",
    //   "client_id": "109982228323456925225",
    //   "auth_uri": "https://accounts.google.com/o/oauth2/auth",
    //   "token_uri": "https://oauth2.googleapis.com/token",
    //   "auth_provider_x509_cert_url": "https://www.googleapis.com/oauth2/v1/certs",
    //   "client_x509_cert_url": "https://www.googleapis.com/robot/v1/metadata/x509/pip-564%40chilkatcloud.iam.gserviceaccount.com"
    // }

    CkAuthGoogle gAuth;
    gAuth.put_JsonKey(jsonKey);

    // Choose the scope for read/write access.
    gAuth.put_Scope("https://www.googleapis.com/auth/tasks");

    // Request an access token that is valid for this many seconds.
    gAuth.put_ExpireNumSeconds(3600);

    gAuth.put_SubEmailAddress("");

    // Connect to www.googleapis.com using TLS
    CkSocket tlsSock;
    bool success = tlsSock.Connect("www.googleapis.com",443,true,5000);
    if (success != true) {
        std::cout << tlsSock.lastErrorText() << "\r\n";
        return;
    }

    // Send the request to obtain the access token.
    success = gAuth.ObtainAccessToken(tlsSock);
    if (success != true) {
        std::cout << gAuth.lastErrorText() << "\r\n";
        return;
    }

    // Examine the access token:
    std::cout << "Access Token: " << gAuth.accessToken() << "\r\n";

    // Save our access token to a file.
    success = fac.WriteEntireTextFile("qa_data/tokens/googleTasks.txt",gAuth.accessToken(),"utf-8",false);
    }