C

Get a Google People API OAuth2 Access Token

See more Google People Examples

Demonstrates how to get a Google People OAuth2 access token from a desktop application or script. C

#include <C_CkOAuth2.h>
#include <C_CkStringBuilder.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkOAuth2 oauth2;
    const char *url;
    int numMsWaited;
    HCkStringBuilder sbJson;

    success = FALSE;

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

    oauth2 = CkOAuth2_Create();

    //  For Google OAuth2, set the ListenPort equal to the port specified in the authorized callback URI for the ClientID.
    //  See http://cknotes.com/setup-google-account-for-google-drive-api-walkthrough/
    CkOAuth2_putListenPort(oauth2,3017);

    CkOAuth2_putAuthorizationEndpoint(oauth2,"https://accounts.google.com/o/oauth2/v2/auth");
    CkOAuth2_putTokenEndpoint(oauth2,"https://www.googleapis.com/oauth2/v4/token");

    //  Replace these with actual values.
    CkOAuth2_putClientId(oauth2,"GOOGLE-CLIENT-ID");
    CkOAuth2_putClientSecret(oauth2,"GOOGLE-CLIENT-SECRET");

    CkOAuth2_putCodeChallenge(oauth2,TRUE);
    CkOAuth2_putCodeChallengeMethod(oauth2,"S256");

    //  See Google People API Scopes for more scopes.
    CkOAuth2_putScope(oauth2,"profile https://www.googleapis.com/auth/contacts https://www.googleapis.com/auth/contacts.other.readonly https://www.googleapis.com/auth/directory.readonly");

    //  Begin the OAuth2 three-legged flow.  This returns a URL that should be loaded in a browser.
    url = CkOAuth2_startAuth(oauth2);
    if (CkOAuth2_getLastMethodSuccess(oauth2) == FALSE) {
        printf("%s\n",CkOAuth2_lastErrorText(oauth2));
        CkOAuth2_Dispose(oauth2);
        return;
    }

    //  Launch the system's default browser navigated to the URL.
    success = CkOAuth2_LaunchBrowser(oauth2,url);
    if (success == FALSE) {
        printf("%s\n",CkOAuth2_lastErrorText(oauth2));
        CkOAuth2_Dispose(oauth2);
        return;
    }

    //  Now wait for the authorization.
    //  We'll wait for a max of 30 seconds.
    numMsWaited = 0;
    while ((numMsWaited < 30000) && (CkOAuth2_getAuthFlowState(oauth2) < 3)) {
        CkOAuth2_SleepMs(oauth2,100);
        numMsWaited = numMsWaited + 100;
    }

    //  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_getAuthFlowState(oauth2) < 3) {
        CkOAuth2_Cancel(oauth2);
        printf("No response from the browser!\n");
        CkOAuth2_Dispose(oauth2);
        return;
    }

    //  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_getAuthFlowState(oauth2) == 5) {
        printf("OAuth2 failed to complete.\n");
        printf("%s\n",CkOAuth2_failureInfo(oauth2));
        CkOAuth2_Dispose(oauth2);
        return;
    }

    if (CkOAuth2_getAuthFlowState(oauth2) == 4) {
        printf("OAuth2 authorization was denied.\n");
        printf("%s\n",CkOAuth2_accessTokenResponse(oauth2));
        CkOAuth2_Dispose(oauth2);
        return;
    }

    if (CkOAuth2_getAuthFlowState(oauth2) != 3) {
        printf("Unexpected AuthFlowState:%d\n",CkOAuth2_getAuthFlowState(oauth2));
        CkOAuth2_Dispose(oauth2);
        return;
    }

    //  Save the full JSON access token response to a file.
    sbJson = CkStringBuilder_Create();
    CkStringBuilder_Append(sbJson,CkOAuth2_accessTokenResponse(oauth2));
    CkStringBuilder_WriteFile(sbJson,"qa_data/tokens/googlePeople.json","utf-8",FALSE);

    //  The saved JSON response looks like this:

    //  {
    //    "access_token": "ya29.a0AfH6S ... LAZYFUkf0",
    //    "expires_in": 3599,
    //    "refresh_token": "1//0fL_Ov ... ee0",
    //    "scope": "https://www.googleapis.com/auth/contacts",
    //    "token_type": "Bearer"
    //  }

    printf("OAuth2 authorization granted!\n");
    printf("Access Token = %s\n",CkOAuth2_accessToken(oauth2));


    CkOAuth2_Dispose(oauth2);
    CkStringBuilder_Dispose(sbJson);

    }