Unicode C++

Dropbox: OAuth2 Authorization to Obtain an Access Token

See more Dropbox Examples

Demonstrates how to get a Dropbox OAuth2 access token from a desktop application or script.

This example runs the OAuth 2.0 authorization flow that lets the user sign in to Dropbox and authorize your app.

Unicode C++

#include <CkOAuth2W.h>
#include <CkJsonObjectW.h>

void ChilkatSample(void)
    {
    bool success = false;

    //  For more information about the OAuth2, see OAuth 2.0 Authorization Flow

    CkOAuth2W oauth2;

    //  The port should match the Authorized Redirect URL in your Dropbox app, 
    //  which would look like "http://localhost:3017/"
    oauth2.put_ListenPort(3017);

    //  IMPORTANT: One of the OAuth2 redirect URIs for your Dropbox app must be
    //  exactly this string:  http://localhost:3017/

    oauth2.put_AuthorizationEndpoint(L"https://www.dropbox.com/oauth2/authorize");
    oauth2.put_TokenEndpoint(L"https://api.dropboxapi.com/oauth2/token");

    //  Replace this with your actual Dropbox App Key
    oauth2.put_ClientId(L"DROPBOX_APP_KEY");

    //  This is for Require Proof Key for Code Exchange (PKCE)
    //  See OAuth2 PKCE Explained
    oauth2.put_CodeChallenge(true);
    oauth2.put_CodeChallengeMethod(L"S256");

    //  Add token_access_type=offline to also get a refresh token in the response
    oauth2.AddAuthQueryParam(L"token_access_type",L"offline");

    //  Begin the OAuth2 Authorization code flow.  This returns a URL that should be loaded in a browser.
    const wchar_t *url = oauth2.startAuth();
    if (oauth2.get_LastMethodSuccess() == false) {
        wprintf(L"%s\n",oauth2.lastErrorText());
        return;
    }

    wprintf(L"url = %s\n",url);

    //  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 == false) {
        wprintf(L"%s\n",oauth2.lastErrorText());
        return;
    }

    //  Wait for the user to approve or deny authorization in the browser.
    int numMsWaited = 0;
    while ((numMsWaited < 90000) && (oauth2.get_AuthFlowState() < 3)) {
        oauth2.SleepMs(100);
        numMsWaited = numMsWaited + 100;
    }

    //  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.get_AuthFlowState() < 3) {
        oauth2.Cancel();
        wprintf(L"No response from the browser!\n");
        return;
    }

    //  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.get_AuthFlowState() == 5) {
        wprintf(L"OAuth2 failed to complete.\n");
        wprintf(L"%s\n",oauth2.failureInfo());
        return;
    }

    if (oauth2.get_AuthFlowState() == 4) {
        wprintf(L"OAuth2 authorization was denied.\n");
        wprintf(L"%s\n",oauth2.accessTokenResponse());
        return;
    }

    if (oauth2.get_AuthFlowState() != 3) {
        wprintf(L"Unexpected AuthFlowState:%d\n",oauth2.get_AuthFlowState());
        return;
    }

    wprintf(L"OAuth2 authorization granted!\n");

    CkJsonObjectW json;
    json.Load(oauth2.accessTokenResponse());
    json.put_EmitCompact(false);

    wprintf(L"Access Token Response = %s\n",json.emit());

    //  A sample access token response:

    //  {
    //    "access_token": "...",
    //    "token_type": "bearer",
    //    "expires_in": 14399,
    //    "refresh_token": "...",
    //    "scope": "account_info.read",
    //    "uid": "562542581",
    //    "account_id": "dbid:AACQhDS0E3_Vb72Ynd0F-GxGWdTI2qcTHzA"
    //  }

    wprintf(L"Access Token = %s\n",oauth2.accessToken());

    //  Save the JSON access token response to a file for subsequent use..
    json.WriteFile(L"qa_data/tokens/dropbox.json");
    }