OAuth & facebook access_token not working, need OAuth expert

问题

I have read the 1000+ blogs about how the redirect_uri has to be the same in both calls to OAuth in order to get a user token, but 100% of the time, regardless of how I format the URL, it fails with:

{
   "error": {
      "message": "Error validating verification code. Please make sure your redirect_uri is identical to the one you used in the OAuth dialog request",
      "type": "OAuthException",
      "code": 100
   }
}

I have been meticulous in making sure that the URLs in both calls were the exact same. My URL has to have a ? in it and I have tried replacing it with %3f but that didn't help. There has to be something else that can cause this error, I need to learn what that might be?

This seemed to break for me over the past month sometime. We did a show in late July and things worked fine (had a different base URL for that show since it was a different server). Could it be that the URL is of this format:

someprestuff.morestuff.mainurl.com?prm=value

Are there too many "parts" to the URL for Facebook to accept it?

I'm looking for alternate things to look for.

回答1:

The url should be the same and it has to be escaped. In the url it has to look like this:

http%3A//someprestuff.morestuff.mainurl.com%3Fprm%3Dvalue

回答2:

Jim's comment above worked, but to clarify, it was a forward slash that fixed it for us.

回答3:

Had the same problem today, the problem turned out to be that the redirect_uri used a http:// URL Schema, and Facebook only accepts https://

回答4:

I just finished tracing this issue on a server that was behind a load balancer. It turns out that while the load balancer was passing the HTTP_X_FORWARDED_PROTO header, somehow between the V3 PHP Facebook library, PHP and Apache, the header was not being recognized.

Here is the relevant code from the library:

 protected function getHttpProtocol() {
    if ($this->trustForwarded && isset($_SERVER['HTTP_X_FORWARDED_PROTO'])) {
      if ($_SERVER['HTTP_X_FORWARDED_PROTO'] === 'https') {
        return 'https';
      }
      return 'http';
    }
    /*apache + variants specific way of checking for https*/
    if (isset($_SERVER['HTTPS']) &&
        ($_SERVER['HTTPS'] === 'on' || $_SERVER['HTTPS'] == 1)) {
      return 'https';
    }
    /*nginx way of checking for https*/
    if (isset($_SERVER['SERVER_PORT']) &&
        ($_SERVER['SERVER_PORT'] === '443')) {
      return 'https';
    }
    return 'http';
 }

As you can see, there are a few scenarios being accommodated here, so you'll have to ensure that whatever situation applies to you is properly configured for this block of code to succeed.

The most likely solution will be to set trustForwarded to true in your facebook config array.

来源：https://stackoverflow.com/questions/13440076/oauth-facebook-access-token-not-working-need-oauth-expert