Find Facebook user (url to profile page) by known email address

Question

I have an email address and want to find out if there is a Facebook user linked to this address. If there is, then I want to retrieve the url to this users profile page and

Answer 1

I've captured the communication of Outlook plugin for Facebook and here is the POST request

https://api.facebook.com/method/fql.multiquery
access_token=TOKEN&queries={"USER0":"select '0', uid, name, birthday_date, profile_url, pic, website from user where uid in (select uid from email where email in ('EMAIL_HASH'))","PENDING_OUT":"select uid_to from friend_request where uid_from = MY_ID and (uid_to IN (select uid from #USER0))"}

where
TOKEN - valid access token
EMAIL_HASH - combination of CRC32 and MD5 hash of searched email address in format crc32_md5
MY_ID - ID of facebook profile of access token owner

But when I run this query with different access token (generated for my own application) the server response is: "The table you requested does not exist" I also haven't found the table email in Facebook API documentation. Does Microsoft have some extra rights at Facebook?

Answer 2

Andreas, I've also been looking for an "email-to-id" ellegant solution and couldn't find one. However, as you said, screen scraping is not such a bad idea in this case, because emails are unique and you either get a single match or none. As long as Facebook don't change their search page drastically, the following will do the trick:

final static String USER_SEARCH_QUERY = "http://www.facebook.com/search.php?init=s:email&q=%s&type=users";
final static String USER_URL_PREFIX = "http://www.facebook.com/profile.php?id=";

public static String emailToID(String email)
{
    try
    {
        String html = getHTML(String.format(USER_SEARCH_QUERY, email));
        if (html != null)
        {
            int i = html.indexOf(USER_URL_PREFIX) + USER_URL_PREFIX.length();
            if (i > 0)
            {
                StringBuilder sb = new StringBuilder();
                char c;
                while (Character.isDigit(c = html.charAt(i++)))
                    sb.append(c);
                if (sb.length() > 0)
                    return sb.toString();
            }
        }
    } catch (Exception e)
    {
        e.printStackTrace();
    }
    return null;
}

private static String getHTML(String htmlUrl) throws MalformedURLException, IOException
{
    StringBuilder response = new StringBuilder();
    URL url = new URL(htmlUrl);
    HttpURLConnection httpConn = (HttpURLConnection) url.openConnection();
    httpConn.setRequestMethod("GET");
    if (httpConn.getResponseCode() == HttpURLConnection.HTTP_OK)
    {
        BufferedReader input = new BufferedReader(new InputStreamReader(httpConn.getInputStream()), 8192);
        String strLine = null;
        while ((strLine = input.readLine()) != null)
            response.append(strLine);
        input.close();
    }
    return (response.length() == 0) ? null : response.toString();
}

Answer 3

First I thank you. # 57ar7up and I will add the following code it helps in finding the return phone number.

function index(){
    // $keyword = "0946664869";
    $sql = "SELECT * FROM phone_find LIMIT 10";
    $result =  $this->GlobalMD->query_global($sql);
    $fb = array();
    foreach($result as $value){
        $keyword = $value['phone'];
        $fb[] = $this->facebook_search($keyword);
    }
    var_dump($fb);

}

function facebook_search($query, $type = 'all'){
    $url = 'http://www.facebook.com/search/'.$type.'/?q='.$query;
    $user_agent = $this->loaduserAgent();

    $c = curl_init();
    curl_setopt_array($c, array(
        CURLOPT_URL             => $url,
        CURLOPT_USERAGENT       => $user_agent,
        CURLOPT_RETURNTRANSFER  => TRUE,
        CURLOPT_FOLLOWLOCATION  => TRUE,
        CURLOPT_SSL_VERIFYPEER  => FALSE
    ));
    $data = curl_exec($c);
    preg_match('/\&#123;&quot;id&quot;:(?P<fbUserId>\d+)\,/', $data, $matches);
    if(isset($matches["fbUserId"]) && $matches["fbUserId"] != ""){
        $fbUserId = $matches["fbUserId"];
        $params = array($query,$fbUserId);
    }else{
        $fbUserId = "";
        $params = array($query,$fbUserId);
    }
    return $params;
}

Answer 4

The definitive answer to this is from Facebook themselves. In post today at https://developers.facebook.com/bugs/335452696581712 a Facebook dev says

The ability to pass in an e-mail address into the "user" search type was
removed on July 10, 2013. This search type only returns results that match
a user's name (including alternate name).

So, alas, the simple answer is you can no longer search for users by their email address. This sucks, but that's Facebook's new rules.

Answer 5

Maybe things changed, but I recall rapleaf had a service where you enter an email address and you could receive a facebook id.
https://www.rapleaf.com/

If something was not in there, one could "sign up" with the email, and it should have a chance to get the data after a while.

I came across this when using a search tool called Maltego a few years back.
The app uses many types of "transforms", and a few where related to facebook and twitter etc..

..or find some new sqli's on fb and fb apps, hehe. :)