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lrduques's avatar
lrduques
Helpful | Level 6
6 years ago

OAuth2 access token request invalid - grant_type expecting \"authorization_code"\

Hi,

I am trying to obtain an acces token by converting the authorization code. I followed both documentation available in the following links: 

https://www.dropbox.com/developers-v1/core/docs#oa2-token

https://blogs.dropbox.com/developers/2013/07/using-oauth-2-0-with-the-core-api/

This is the code I am runing after being redirected from Dropbox page:

<?php 
if (isset($_GET['code'])) {
	
    echo 'UserCode -> ' . $_GET['code'];

    $ch = curl_init();
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");
    curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-Type: application/x-www-form-urlencoded'));
    curl_setopt($ch, CURLOPT_URL, "https://api.dropboxapi.com/oauth2/token");
    curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query(array('code'=> $_GET['code'], 'client_id' => "5n5**********aw", 'client_secret' => "zq**********tn8", 'grant_type' => $_GET['code'], 'redirect_uri' => 'http://localhost/optiSurface-dropbox/login.php')));
    
    $response = curl_exec($ch);

    echo '<pre>';
    var_dump($response);
    echo '</pre>';

}else{
	header('Location: http://localhost/optiSurface-dropbox/curl-auth1.php');
}

However, I am receiving a error message as follow:

string(154) "{"error_description": "\"grant_type\": got \"L22mWRF0R0AAAAAAAAAGt4o3aW761b9KrBSPgX6OugA\", expecting \"authorization_code\"", "error": "invalid_request"}"

As the error message says, it was expecting the authorization code. I am unsure what variable/data to use in this parameter. 

Reading the documentation, I noted that is the same value from code attribute:

curl https://api.dropbox.com/oauth2/token \
    -d code=<AUTHORIZATION_CODE> \
    -d grant_type=authorization_code \
    -d redirect_uri=<REDIRECT_URI> \
    -u <APP_KEY>:<APP_SECRET>

How can I fix this problem?

Thank you in advance!

  • The "grant_type" parameter value should literally be the string "authorization_code", and only the "code" parameter value should be the authorization code string you received. 

    That is to say, your parameter line should like something like this instead:

        curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query(array('code'=> $_GET['code'], 'client_id' => "5n5**********aw", 'client_secret' => "zq**********tn8", 'grant_type' => "authorization_code", 'redirect_uri' => 'http://localhost/optiSurface-dropbox/login.php')));

    By the way, you linked to the old version of the documentation. For reference, the current version is here: https://www.dropbox.com/developers/documentation/http/documentation#oauth2-token 

  • Problem solved!! 

    I just realized it's not necessary to include the complete path from the URL. Since the app has permission to access just it's own folder, I just included the file path itself.

    So my json file it's like this:

    {
        "path": "/text.txt",
        "include_media_info": false,
        "include_deleted": false,
        "include_has_explicit_shared_members": false
    }

    Thank you!!

  • Greg-DB's avatar
    Greg-DB
    Icon for Dropbox Staff rankDropbox Staff

    The "grant_type" parameter value should literally be the string "authorization_code", and only the "code" parameter value should be the authorization code string you received. 

    That is to say, your parameter line should like something like this instead:

        curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query(array('code'=> $_GET['code'], 'client_id' => "5n5**********aw", 'client_secret' => "zq**********tn8", 'grant_type' => "authorization_code", 'redirect_uri' => 'http://localhost/optiSurface-dropbox/login.php')));

    By the way, you linked to the old version of the documentation. For reference, the current version is here: https://www.dropbox.com/developers/documentation/http/documentation#oauth2-token 

    • lrduques's avatar
      lrduques
      Helpful | Level 6

      Thank you Greg!

      I am trying to list the files (/get_metadata) in my app folder but for some reason I can't set up the correct path. Take a look at this message:

      {"error_summary": "path/not_found/", "error": {".tag": "path", "path": {".tag": "not_found"}}}

      The app folder was automatically created by Dropbox, and after that I created a txt file named text.txt inside it. As you can see, this is the path:

       

      However, when I send the /get_metadata request via curl I receive the error message that the path dosen't exist.

      This is the json file - named getMetadata.json - with the parameters:

      {
          "path": "/home/Aplicativos/optisurface",
          "include_media_info": false,
          "include_deleted": false,
          "include_has_explicit_shared_members": false
      }

      This is the curl request I am using:

      <?php 
      
      require_once 'Functions/functions.php';
      
      $token = getToken($_SESSION['uid']);
      
      $data  = file_get_contents('json/getMetadata.json');
      
      	$ch = curl_init();
          
          curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
          curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");
          curl_setopt($ch, CURLOPT_HTTPHEADER, array('Authorization: Bearer ' . $token[0]->itoken, 'Content-Type: application/json'));
          curl_setopt($ch, CURLOPT_URL, "https://api.dropboxapi.com/2/files/get_metadata");
          curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
          
          $response = curl_exec($ch);
      
          echo '<pre>';
          print_r($response);
          echo '</pre>';
      
       ?>

      Can you help me saying what am I doing wrong?

      • lrduques's avatar
        lrduques
        Helpful | Level 6

        Meanwhile, I used the /list_folder request since it supports root path just by leaving it empty "".

        {"entries": [{".tag": "file", "name": "text.txt", "path_lower": "/text.txt", "path_display": "/text.txt", "id": "id:WEoRMx3RGMAAAAAAAAAAJg", "client_modified": "2019-03-08T00:23:18Z", "server_modified": "2019-03-08T00:23:18Z", "rev": "012000000012ec82090", "size": 5, "content_hash": "fe362d76b941f8f883e360e1a7bd26c78d4252c8229621711d6857846a2285f8"}], "cursor": "AAGNZvzM-WGZO5F9XFCBcrTUsT6mhUTRHnnY12-dD6lPgRK-hUZFzy8zMvgbnPMBuvKpIFY-1-QTfe0m_qpJMEE0hUs-JHq_gvzY1gGg2zIEblN0sE8MaGJnnyI_9a5dTi8CwzzfjgwL86mZtZL6UbMi", "has_more": false}

        But I really want to understand why /get_metadata ins't working because in future code I'll need to access specifics paths.

        Thank you in advance!