OAuth（开放授权协议）

oauth是Open Authorization的简写。oauth协议为用户资源的授权提供了一个安全的、开放而又建议的标准。oauth的授权不会是第三方初级到用户的账号信息（如用户名与密码），及第三方无需使用用户的用户名与密码就可以申请获得该用户资源的授权，因此oauth是安全的。

安装此 PECL 扩展相关的信息可在手册中标题为 PECL 扩展的安装章节中找到。更多信息如新的发行版本、下载、源文件、 维护人员信息及变更日志等，都在此处： https://pear.php.net/package/oauth

<?php
$req_url = 'https://fireeagle.yahooapis.com/oauth/request_token';
$authurl = 'https://fireeagle.yahoo.net/oauth/authorize';
$acc_url = 'https://fireeagle.yahooapis.com/oauth/access_token';
$api_url = 'https://fireeagle.yahooapis.com/api/0.1';
$conskey = 'your_consumer_key';
$conssec = 'your_consumer_secret';
session_start();
//  当 state=1 则下次请求应该包含一个 oauth_token 。
//  如果没有则返回 0
if(!isset($_GET['oauth_token']) && $_SESSION['state']==1) $_SESSION['state'] = 0;
try {
  $oauth = new OAuth($conskey,$conssec,OAUTH_SIG_METHOD_HMACSHA1,OAUTH_AUTH_TYPE_URI);
  $oauth->enableDebug();
  if(!isset($_GET['oauth_token']) && !$_SESSION['state']) {
    $request_token_info = $oauth->getRequestToken($req_url);
    $_SESSION['secret'] = $request_token_info['oauth_token_secret'];
    $_SESSION['state'] = 1;
    header('Location: '.$authurl.'?oauth_token='.$request_token_info['oauth_token']);
    exit;
  } else if($_SESSION['state']==1) {
    $oauth->setToken($_GET['oauth_token'],$_SESSION['secret']);
    $access_token_info = $oauth->getAccessToken($acc_url);
    $_SESSION['state'] = 2;
    $_SESSION['token'] = $access_token_info['oauth_token'];
    $_SESSION['secret'] = $access_token_info['oauth_token_secret'];
  } 
  $oauth->setToken($_SESSION['token'],$_SESSION['secret']);
  $oauth->fetch("$api_url/user.json");
  $json = json_decode($oauth->getLastResponse());
  print_r($json);
} catch(OAuthException $E) {
  print_r($E);
}
?>

I have just managed to modify this script to work with the Twitter API...
The changes are...
$req_url = 'https://api.twitter.com/oauth/request_token';
$authurl = 'https://api.twitter.com/oauth/authorize';
$acc_url = 'https://api.twitter.com/oauth/access_token';
$api_url = 'https://api.twitter.com/1.1/account';
$conskey = 'YOURAPPconskey';
$conssec = 'YOURAPPconssec';
And change
#$oauth->fetch("$api_url/user.json");
# verify_credentials
# TO
$oauth->fetch("$api_url/verify_credentials.json");

Fire Eagle has closed as of February 2013

In the case you're asking an API which gives you a reusable application key, you'll have to use the "verifier" in the getAccessToken() method, but also the "callback" parameter in the getRequestToken().
<?php
   $request_token_info = $oauth->getRequestToken($req_url, "<YOU_CALLBACK_URI>");
?>
In my case, once I accepted the form in the Authorize URI, I was redirected to this callback URI with a "oauth_verifier" GET parameter. I injected it into the access token request : 
<?php
  $access_token_info = $oauth->getAccessToken($acc_url, '', $_GET['oauth_verifier']);
?>
I finally obtained an access token that I hardcoded ; it doesn't need any refresh.