net.manuellemos.oauth @(#) $Id: oauth_client.php,v 1.58 2013/04/11 09:33:16 mlemos Exp $ Copyright © (C) Manuel Lemos 2012 OAuth client Manuel Lemos mlemos-at-acm.org en This class serves two main purposes: 1) Implement the OAuth protocol to retrieve a token from a server to authorize the access to an API on behalf of the current user. 2) Perform calls to a Web services API using a token previously obtained using this class or a token provided some other way by the Web services provider. Regardless of your purposes, you always need to start calling the class Initialize function after initializing setup variables. After you are done with the class, always call the Finalize function at the end. This class supports either OAuth protocol versions 1.0, 1.0a and 2.0. It abstracts the differences between these protocol versions, so the class usage is the same independently of the OAuth version of the server. The class also provides built-in support to several popular OAuth servers, so you do not have to manually configure all the details to access those servers. Just set the server variable to configure the class to access one of the built-in supported servers. If you need to access one type of server that is not yet directly supported by the class, you need to configure it explicitly setting the variables: oauth_version, url_parameters, authorization_header, request_token_url, dialog_url, offline_dialog_url, append_state_to_redirect_uri and access_token_url. Before proceeding to the actual OAuth authorization process, you need to have registered your application with the OAuth server. The registration provides you values to set the variables client_id and client_secret. You also need to set the variables redirect_uri and scope before calling the Process function to make the class perform the necessary interactions with the OAuth server. The OAuth protocol involves multiple steps that include redirection to the OAuth server. There it asks permission to the current user to grant your application access to APIs on his/her behalf. When there is a redirection, the class will set the exit variable to 1. Then your script should exit immediately without outputting anything. When the OAuth access token is successfully obtained, the following variables are set by the class with the obtained values: access_token, access_token_secret, access_token_expiry, access_token_type. You may want to store these values to use them later when calling the server APIs. If there was a problem during OAuth authorization process, check the variable authorization_error to determine the reason. Once you get the access token, you can call the server APIs using the CallAPI function. Check the access_token_error variable to determine if there was an error when trying to to call the API. If for some reason the user has revoked the access to your application, you need to ask the user to authorize your application again. First you may need to call the function ResetAccessToken to reset the value of the access token that may be cached in session variables. {/metadocument} */ class oauth_client_class { /* {metadocument} error STRING Store the message that is returned when an error occurs. Check this variable to understand what happened when a call to any of the class functions has failed. This class uses cumulative error handling. This means that if one class functions that may fail is called and this variable was already set to an error message due to a failure in a previous call to the same or other function, the function will also fail and does not do anything. This allows programs using this class to safely call several functions that may fail and only check the failure condition after the last function call. Just set this variable to an empty string to clear the error condition. {/metadocument} */ var $error = ''; /* {metadocument} debug BOOLEAN 0 Control whether debug output is enabled Set this variable to 1 if you need to check what is going on during calls to the class. When enabled, the debug output goes either to the variable debug_output and the PHP error log. {/metadocument} */ var $debug = false; /* {metadocument} debug_http BOOLEAN 0 Control whether the dialog with the remote Web server should also be logged. Set this variable to 1 if you want to inspect the data exchange with the OAuth server. {/metadocument} */ var $debug_http = false; /* {metadocument} exit BOOLEAN 0 Determine if the current script should be exited. Check this variable after calling the Process function and exit your script immediately if the variable is set to 1. {/metadocument} */ var $exit = false; /* {metadocument} debug_output STRING Capture the debug output generated by the class Inspect this variable if you need to see what happened during the class function calls. {/metadocument} */ var $debug_output = ''; /* {metadocument} debug_prefix STRING OAuth client: Mark the lines of the debug output to identify actions performed by this class. Change this variable if you prefer the debug output lines to be prefixed with a different text. {/metadocument} */ var $debug_prefix = 'OAuth client: '; /* {metadocument} server STRING Identify the type of OAuth server to access. The class provides built-in support to several types of OAuth servers. This means that the class can automatically initialize several configuration variables just by setting this server variable. Currently it supports the following servers: Bitbucket, Box, Dropbox, Eventful, Facebook, Fitbit, Flickr, Foursquare, github, Google, Instagram, LinkedIn, Microsoft, Scoop.it, StockTwits, Tumblr, Twitter, XING and Yahoo. Please contact the author if you would like to ask to add built-in support for other types of OAuth servers. If you want to access other types of OAuth servers that are not yet supported, set this variable to an empty string and configure other variables with values specific to those servers. {/metadocument} */ var $server = ''; /* {metadocument} request_token_url STRING URL of the OAuth server to request the initial token for OAuth 1.0 and 1.0a servers. Set this variable to the OAuth request token URL when you are not accessing one of the built-in supported OAuth servers. For OAuth 1.0 and 1.0a servers, the request token URL can have certain marks that will act as template placeholders which will be replaced with given values before requesting the authorization token. Currently it supports the following placeholder marks: {SCOPE} - scope of the requested permissions to the granted by the OAuth server with the user permissions {/metadocument} */ var $request_token_url = ''; /* {metadocument} dialog_url STRING URL of the OAuth server to redirect the browser so the user can grant access to your application. Set this variable to the OAuth request token URL when you are not accessing one of the built-in supported OAuth servers. For certain servers, the dialog URL can have certain marks that will act as template placeholders which will be replaced with values defined before redirecting the users browser. Currently it supports the following placeholder marks: {REDIRECT_URI} - URL to redirect when returning from the OAuth server authorization page {CLIENT_ID} - client application identifier registered at the server {SCOPE} - scope of the requested permissions to the granted by the OAuth server with the user permissions {STATE} - identifier of the OAuth session state {/metadocument} */ var $dialog_url = ''; /* {metadocument} offline_dialog_url STRING URL of the OAuth server to redirect the browser so the user can grant access to your application when offline access is requested. Set this variable to the OAuth request token URL when you are not accessing one of the built-in supported OAuth servers and the OAuth server supports offline access. It should have the same format as the dialog_url variable. {/metadocument} */ var $offline_dialog_url = ''; /* {metadocument} append_state_to_redirect_uri STRING Pass the OAuth session state in a variable with a different name to work around implementation bugs of certain OAuth servers Set this variable when you are not accessing one of the built-in supported OAuth servers if the OAuth server has a bug that makes it not pass back the OAuth state identifier in a request variable named state. {/metadocument} */ var $append_state_to_redirect_uri = ''; /* {metadocument} access_token_url STRING OAuth server URL that will return the access token URL. Set this variable to the OAuth access token URL when you are not accessing one of the built-in supported OAuth servers. {/metadocument} */ var $access_token_url = ''; /* {metadocument} oauth_version STRING 2.0 Version of the protocol version supported by the OAuth server. Set this variable to the OAuth server protocol version when you are not accessing one of the built-in supported OAuth servers. {/metadocument} */ var $oauth_version = '2.0'; /* {metadocument} url_parameters BOOLEAN 0 Determine if the API call parameters should be moved to the call URL. Set this variable to 1 if the API you need to call requires that the call parameters always be passed via the API URL. {/metadocument} */ var $url_parameters = false; /* {metadocument} authorization_header BOOLEAN 1 Determine if the OAuth parameters should be passed via HTTP Authorization request header. Set this variable to 1 if the OAuth server requires that the OAuth parameters be passed using the HTTP Authorization instead of the request URI parameters. {/metadocument} */ var $authorization_header = true; /* {metadocument} token_request_method STRING GET Define the HTTP method that should be used to request tokens from the server. Set this variable to POST if the OAuth server does not support requesting tokens using the HTTP GET method. {/metadocument} */ var $token_request_method = 'GET'; /* {metadocument} signature_method STRING HMAC-SHA1 Define the method to generate the signature for API request parameters values. Currently it supports PLAINTEXT and HMAC-SHA1. {/metadocument} */ var $signature_method = 'HMAC-SHA1'; /* {metadocument} redirect_uri STRING URL of the current script page that is calling this class Set this variable to the current script page URL before proceeding the the OAuth authorization process. {/metadocument} */ var $redirect_uri = ''; /* {metadocument} client_id STRING Identifier of your application registered with the OAuth server Set this variable to the application identifier that is provided by the OAuth server when you register the application. {/metadocument} */ var $client_id = ''; /* {metadocument} client_secret STRING Secret value assigned to your application when it is registered with the OAuth server. Set this variable to the application secret that is provided by the OAuth server when you register the application. {/metadocument} */ var $client_secret = ''; /* {metadocument} scope STRING Permissions that your application needs to call the OAuth server APIs Check the documentation of the APIs that your application needs to call to set this variable with the identifiers of the permissions that the user needs to grant to your application. {/metadocument} */ var $scope = ''; /* {metadocument} offline BOOLEAN 0 Specify whether it will be necessary to call the API when the user is not present and the server supports renewing expired access tokens using refresh tokens. Set this variable to 1 if the server supports renewing expired tokens automatically when the user is not present. {/metadocument} */ var $offline = false; /* {metadocument} access_token STRING Access token obtained from the OAuth server Check this variable to get the obtained access token upon successful OAuth authorization. {/metadocument} */ var $access_token = ''; /* {metadocument} access_token_secret STRING Access token secret obtained from the OAuth server If the OAuth protocol version is 1.0 or 1.0a, check this variable to get the obtained access token secret upon successful OAuth authorization. {/metadocument} */ var $access_token_secret = ''; /* {metadocument} access_token_expiry STRING Timestamp of the expiry of the access token obtained from the OAuth server. Check this variable to get the obtained access token expiry time upon successful OAuth authorization. If this variable is empty, that means no expiry time was set. {/metadocument} */ var $access_token_expiry = ''; /* {metadocument} access_token_type STRING Type of access token obtained from the OAuth server. Check this variable to get the obtained access token type upon successful OAuth authorization. {/metadocument} */ var $access_token_type = ''; /* {metadocument} refresh_token STRING Refresh token obtained from the OAuth server Check this variable to get the obtained refresh token upon successful OAuth authorization. {/metadocument} */ var $refresh_token = ''; /* {metadocument} access_token_error STRING Error message returned when a call to the API fails. Check this variable to determine if there was an error while calling the Web services API when using the CallAPI function. {/metadocument} */ var $access_token_error = ''; /* {metadocument} authorization_error STRING Error message returned when it was not possible to obtain an OAuth access token Check this variable to determine if there was an error while trying to obtain the OAuth access token. {/metadocument} */ var $authorization_error = ''; /* {metadocument} response_status INTEGER 0 HTTP response status returned by the server when calling an API Check this variable after calling the CallAPI function if the API calls and you need to process the error depending the response status. 200 means no error. 0 means the server response was not retrieved. {/metadocument} */ var $response_status = 0; var $oauth_user_agent = 'PHP-OAuth-API (http://www.phpclasses.org/oauth-api $Revision: 1.58 $)'; var $session_started = false; Function SetError($error) { $this->error = $error; if($this->debug) $this->OutputDebug('Error: '.$error); return(false); } Function SetPHPError($error, &$php_error_message) { if(IsSet($php_error_message) && strlen($php_error_message)) $error.=": ".$php_error_message; return($this->SetError($error)); } Function OutputDebug($message) { if($this->debug) { $message = $this->debug_prefix.$message; $this->debug_output .= $message."\n";; error_log($message); } return(true); } Function GetRequestTokenURL(&$request_token_url) { $request_token_url = $this->request_token_url; return(true); } Function GetDialogURL(&$url, $redirect_uri = '', $state = '') { $url = (($this->offline && strlen($this->offline_dialog_url)) ? $this->offline_dialog_url : $this->dialog_url); if(strlen($url) === 0) return $this->SetError('the dialog URL '.($this->offline ? 'for offline access ' : '').'is not defined for this server'); $url = str_replace( '{REDIRECT_URI}', UrlEncode($redirect_uri), str_replace( '{STATE}', UrlEncode($state), str_replace( '{CLIENT_ID}', UrlEncode($this->client_id), str_replace( '{SCOPE}', UrlEncode($this->scope), $url)))); return(true); } Function GetAccessTokenURL(&$access_token_url) { $access_token_url = $this->access_token_url; return(true); } Function GetStoredState(&$state) { if(!$this->session_started) { if(!function_exists('session_start')) return $this->SetError('Session variables are not accessible in this PHP environment'); } if(IsSet($_SESSION['OAUTH_STATE'])) $state = $_SESSION['OAUTH_STATE']; else $state = $_SESSION['OAUTH_STATE'] = time().'-'.substr(md5(rand().time()), 0, 6); return(true); } Function GetRequestState(&$state) { $check = (strlen($this->append_state_to_redirect_uri) ? $this->append_state_to_redirect_uri : 'state'); $state = (IsSet($_GET[$check]) ? $_GET[$check] : null); return(true); } Function GetRequestCode(&$code) { $code = (IsSet($_GET['code']) ? $_GET['code'] : null); return(true); } Function GetRequestError(&$error) { $error = (IsSet($_GET['error']) ? $_GET['error'] : null); return(true); } Function GetRequestDenied(&$denied) { $denied = (IsSet($_GET['denied']) ? $_GET['denied'] : null); return(true); } Function GetRequestToken(&$token, &$verifier) { $token = (IsSet($_GET['oauth_token']) ? $_GET['oauth_token'] : null); $verifier = (IsSet($_GET['oauth_verifier']) ? $_GET['oauth_verifier'] : null); return(true); } Function GetRedirectURI(&$redirect_uri) { if(strlen($this->redirect_uri)) $redirect_uri = $this->redirect_uri; else $redirect_uri = 'http://'.$_SERVER['HTTP_HOST'].$_SERVER['REQUEST_URI']; return true; } /* {metadocument} StoreAccessToken BOOLEAN Store the values of the access token when it is succefully retrieved from the OAuth server. This function is meant to be only be called from inside the class. By default it stores access tokens in a session variable named OAUTH_ACCESS_TOKEN. Actual implementations should create a sub-class and override this function to make the access token values be stored in other types of containers, like for instance databases. This function should return 1 if the access token was stored successfully. access_token HASH Associative array with properties of the access token. The array may have set the following properties: value: string value of the access token authorized: boolean value that determines if the access token was obtained successfully expiry: (optional) timestamp in ISO format relative to UTC time zone of the access token expiry time type: (optional) type of OAuth token that may determine how it should be used when sending API call requests. refresh: (optional) token that some servers may set to allowing refreshing access tokens when they expire. {/metadocument} */ Function StoreAccessToken($access_token) { if(!$this->session_started) { if(!function_exists('session_start')) return $this->SetError('Session variables are not accessible in this PHP environment'); } $_SESSION['OAUTH_ACCESS_TOKEN'][$this->access_token_url] = $access_token; return true; } /* {metadocument} {/metadocument} */ /* {metadocument} GetAccessToken BOOLEAN Retrieve the OAuth access token if it was already previously stored by the StoreAccessToken function. This function is meant to be only be called from inside the class. By default it retrieves access tokens stored in a session variable named OAUTH_ACCESS_TOKEN. Actual implementations should create a sub-class and override this function to retrieve the access token values from other types of containers, like for instance databases. This function should return 1 if the access token was retrieved successfully. access_token STRING Return the properties of the access token in an associative array. If the access token was not yet stored, it returns an empty array. Otherwise, the properties it may return are the same that may be passed to the StoreAccessToken. {/metadocument} */ Function GetAccessToken(&$access_token) { if(!$this->session_started) { if(!function_exists('session_start')) return $this->SetError('Session variables are not accessible in this PHP environment'); if(!session_start()) return($this->SetPHPError('it was not possible to start the PHP session', $php_error_message)); $this->session_started = true; } if(IsSet($_SESSION['OAUTH_ACCESS_TOKEN'][$this->access_token_url])) $access_token = $_SESSION['OAUTH_ACCESS_TOKEN'][$this->access_token_url]; else $access_token = array(); return true; } /* {metadocument} {/metadocument} */ /* {metadocument} ResetAccessToken BOOLEAN Reset the access token to a state back when the user has not yet authorized the access to the OAuth server API. Call this function if for some reason the token to access the API was revoked and you need to ask the user to authorize the access again. By default the class stores and retrieves access tokens in a session variable named OAUTH_ACCESS_TOKEN. This function must be called when the user is accessing your site pages, so it can reset the information stored in session variables that cache the state of a previously retrieved access token. Actual implementations should create a sub-class and override this function to reset the access token state when it is stored in other types of containers, like for instance databases. This function should return 1 if the access token was resetted successfully. {/metadocument} */ Function ResetAccessToken() { if($this->debug) $this->OutputDebug('Resetting the access token status for OAuth server located at '.$this->access_token_url); if(!$this->session_started) { if(!function_exists('session_start')) return $this->SetError('Session variables are not accessible in this PHP environment'); if(!session_start()) return($this->SetPHPError('it was not possible to start the PHP session', $php_error_message)); } $this->session_started = true; if(IsSet($_SESSION['OAUTH_ACCESS_TOKEN'][$this->access_token_url])) Unset($_SESSION['OAUTH_ACCESS_TOKEN'][$this->access_token_url]); return true; } /* {metadocument} {/metadocument} */ Function Encode($value) { return(is_array($value) ? $this->EncodeArray($value) : str_replace('%7E', '~', str_replace('+',' ', RawURLEncode($value)))); } Function EncodeArray($array) { foreach($array as $key => $value) $array[$key] = $this->Encode($value); return $array; } Function HMAC($function, $data, $key) { switch($function) { case 'sha1': $pack = 'H40'; break; default: if($this->debug) $this->OutputDebug($function.' is not a supported an HMAC hash type'); return(''); } if(strlen($key) > 64) $key = pack($pack, $function($key)); if(strlen($key) < 64) $key = str_pad($key, 64, "\0"); return(pack($pack, $function((str_repeat("\x5c", 64) ^ $key).pack($pack, $function((str_repeat("\x36", 64) ^ $key).$data))))); } Function SendAPIRequest($url, $method, $parameters, $oauth, $options, &$response) { $this->response_status = 0; $http = new http_class; $http->debug = ($this->debug && $this->debug_http); $http->timeout = 30; $http->data_timeout = 60; $http->log_debug = true; $http->sasl_authenticate = 0; $http->user_agent = $this->oauth_user_agent; $http->redirection_limit = (IsSet($options['FollowRedirection']) ? intval($options['FollowRedirection']) : 0); $http->follow_redirect = ($http->redirection_limit != 0); if($this->debug) $this->OutputDebug('Accessing the '.$options['Resource'].' at '.$url); $post_files = array(); $method = strtoupper($method); $authorization = ''; $type = (IsSet($options['RequestContentType']) ? strtolower(trim(strtok($options['RequestContentType'], ';'))) : 'application/x-www-form-urlencoded'); if(IsSet($oauth)) { $values = array( 'oauth_consumer_key'=>$this->client_id, //'oauth_nonce'=>md5(uniqid(rand(), true)), 'oauth_nonce'=>sha1(uniqid(mt_rand(), true).uniqid(mt_rand(), true)), 'oauth_signature_method'=>$this->signature_method, 'oauth_timestamp'=>time(), 'oauth_version'=>'1.0', ); $files = (IsSet($options['Files']) ? $options['Files'] : array()); if(count($files)) { foreach($files as $name => $value) { if(!IsSet($parameters[$name])) return($this->SetError('it was specified an file parameters named '.$name)); $file = array(); switch(IsSet($value['Type']) ? $value['Type'] : 'FileName') { case 'FileName': $file['FileName'] = $parameters[$name]; break; case 'Data': $file['Data'] = $parameters[$name]; break; default: return($this->SetError($value['Type'].' is not a valid type for file '.$name)); } $file['ContentType'] = (IsSet($value['Content-Type']) ? $value['Content-Type'] : 'automatic/name'); $post_files[$name] = $file; } UnSet($parameters[$name]); if($method !== 'POST') { $this->OutputDebug('For uploading files the method should be POST not '.$method); $method = 'POST'; } if($type !== 'multipart/form-data') { if(IsSet($options['RequestContentType'])) return($this->SetError('the request content type for uploading files should be multipart/form-data')); $type = 'multipart/form-data'; } $value_parameters = array(); } else { if($this->url_parameters && $type === 'application/x-www-form-urlencoded' && count($parameters)) { $first = (strpos($url, '?') === false); foreach($parameters as $parameter => $value) { $url .= ($first ? '?' : '&').UrlEncode($parameter).'='.UrlEncode($value); $first = false; } $parameters = array(); } $value_parameters = ($type !== 'application/x-www-form-urlencoded' ? array() : $parameters); } $values = array_merge($values, $oauth, $value_parameters); $key = $this->Encode($this->client_secret).'&'.$this->Encode($this->access_token_secret); switch($this->signature_method) { case 'PLAINTEXT': $values['oauth_signature'] = $key; break; case 'HMAC-SHA1': $uri = strtok($url, '?'); $sign = $method.'&'.$this->Encode($uri).'&'; $first = true; $sign_values = $values; $u = parse_url($url); if(IsSet($u['query'])) { parse_str($u['query'], $q); foreach($q as $parameter => $value) $sign_values[$parameter] = $value; } KSort($sign_values); foreach($sign_values as $parameter => $value) { $sign .= $this->Encode(($first ? '' : '&').$parameter.'='.$this->Encode($value)); $first = false; } $values['oauth_signature'] = base64_encode($this->HMAC('sha1', $sign, $key)); break; default: return $this->SetError($this->signature_method.' signature method is not yet supported'); } if($this->authorization_header) { $authorization = 'OAuth'; $first = true; foreach($values as $parameter => $value) { $authorization .= ($first ? ' ' : ',').$parameter.'="'.$this->Encode($value).'"'; $first = false; } } else { if($method === 'GET' || (IsSet($options['PostValuesInURI']) && $options['PostValuesInURI'])) { $first = (strcspn($url, '?') == strlen($url)); foreach($values as $parameter => $value) { $url .= ($first ? '?' : '&').$parameter.'='.$this->Encode($value); $first = false; } $post_values = array(); } else $post_values = $values; } } if(strlen($error = $http->GetRequestArguments($url, $arguments))) return($this->SetError('it was not possible to open the '.$options['Resource'].' URL: '.$error)); if(strlen($error = $http->Open($arguments))) return($this->SetError('it was not possible to open the '.$options['Resource'].' URL: '.$error)); if(count($post_files)) $arguments['PostFiles'] = $post_files; $arguments['RequestMethod'] = $method; switch($type) { case 'application/x-www-form-urlencoded': case 'multipart/form-data': if(IsSet($options['RequestBody'])) return($this->SetError('the request body is defined automatically from the parameters')); $arguments['PostValues'] = $parameters; break; case 'application/json': $arguments['Headers']['Content-Type'] = $options['RequestContentType']; if(!IsSet($options['RequestBody'])) { $arguments['Body'] = json_encode($parameters); break; } default: if(!IsSet($options['RequestBody'])) return($this->SetError('it was not specified the body value of the of the API call request')); $arguments['Headers']['Content-Type'] = $options['RequestContentType']; $arguments['Body'] = $options['RequestBody']; break; } $arguments['Headers']['Accept'] = (IsSet($options['Accept']) ? $options['Accept'] : '*/*'); if(strlen($authorization)) $arguments['Headers']['Authorization'] = $authorization; if(strlen($error = $http->SendRequest($arguments)) || strlen($error = $http->ReadReplyHeaders($headers))) { $http->Close(); return($this->SetError('it was not possible to retrieve the '.$options['Resource'].': '.$error)); } $error = $http->ReadWholeReplyBody($data); $http->Close(); if(strlen($error)) { return($this->SetError('it was not possible to access the '.$options['Resource'].': '.$error)); } $this->response_status = intval($http->response_status); $content_type = (IsSet($options['ResponseContentType']) ? $options['ResponseContentType'] : (IsSet($headers['content-type']) ? strtolower(trim(strtok($headers['content-type'], ';'))) : 'unspecified')); switch($content_type) { case 'text/javascript': case 'application/json': if(!function_exists('json_decode')) return($this->SetError('the JSON extension is not available in this PHP setup')); $object = json_decode($data); switch(GetType($object)) { case 'object': if(!IsSet($options['ConvertObjects']) || !$options['ConvertObjects']) $response = $object; else { $response = array(); foreach($object as $property => $value) $response[$property] = $value; } break; case 'array': $response = $object; break; default: if(!IsSet($object)) return($this->SetError('it was not returned a valid JSON definition of the '.$options['Resource'].' values')); $response = $object; break; } break; case 'application/x-www-form-urlencoded': case 'text/plain': case 'text/html': parse_str($data, $response); break; default: $response = $data; break; } if($this->response_status >= 200 && $this->response_status < 300) $this->access_token_error = ''; else { $this->access_token_error = 'it was not possible to access the '.$options['Resource'].': it was returned an unexpected response status '.$http->response_status.' Response: '.$data; if($this->debug) $this->OutputDebug('Could not retrieve the OAuth access. Error: '.$this->access_token_error); if(IsSet($options['FailOnAccessError']) && $options['FailOnAccessError']) { $this->error = $this->access_token_error; return false; } } return true; } Function ProcessToken($code, $refresh) { if($refresh) { $values = array( 'client_id'=>$this->client_id, 'client_secret'=>$this->client_secret, 'refresh_token'=>$this->refresh_token, 'grant_type'=>'refresh_token' ); } else { if(!$this->GetRedirectURI($redirect_uri)) return false; $values = array( 'code'=>$code, 'client_id'=>$this->client_id, 'client_secret'=>$this->client_secret, 'redirect_uri'=>$redirect_uri, 'grant_type'=>'authorization_code' ); } if(!$this->GetAccessTokenURL($url)) return false; if(!$this->SendAPIRequest($url, 'POST', $values, null, array('Resource'=>'OAuth '.($refresh ? 'refresh' : 'access').' token', 'ConvertObjects'=>true), $response)) return false; if(strlen($this->access_token_error)) { $this->authorization_error = $this->access_token_error; return true; } if(!IsSet($response['access_token'])) { if(IsSet($response['error'])) { $this->authorization_error = 'it was not possible to retrieve the access token: it was returned the error: '.$response['error']; return true; } return($this->SetError('OAuth server did not return the access token')); } $access_token = array( 'value'=>$this->access_token = $response['access_token'], 'authorized'=>true ); if($this->debug) $this->OutputDebug('Access token: '.$this->access_token); if(IsSet($response['expires']) || IsSet($response['expires_in'])) { $expires = (IsSet($response['expires']) ? $response['expires'] : $response['expires_in']); if(strval($expires) !== strval(intval($expires)) || $expires <= 0) return($this->SetError('OAuth server did not return a supported type of access token expiry time')); $this->access_token_expiry = gmstrftime('%Y-%m-%d %H:%M:%S', time() + $expires); if($this->debug) $this->OutputDebug('Access token expiry: '.$this->access_token_expiry.' UTC'); $access_token['expiry'] = $this->access_token_expiry; } else $this->access_token_expiry = ''; if(IsSet($response['token_type'])) { $this->access_token_type = $response['token_type']; if($this->debug) $this->OutputDebug('Access token type: '.$this->access_token_type); $access_token['type'] = $this->access_token_type; } else $this->access_token_type = ''; if($refresh) $response['refresh_token'] = $this->refresh_token; elseif(IsSet($response['refresh_token'])) { $this->refresh_token = $response['refresh_token']; if($this->debug) $this->OutputDebug('Refresh token: '.$this->refresh_token); $access_token['refresh'] = $this->refresh_token; } else $this->refresh_token = ''; if(!$this->StoreAccessToken($access_token)) return false; return true; } Function RetrieveToken(&$valid) { $valid = false; if(!$this->GetAccessToken($access_token)) return false; if(IsSet($access_token['value'])) { $this->access_token_expiry = ''; if(IsSet($access_token['expiry']) && strcmp($this->access_token_expiry = $access_token['expiry'], gmstrftime('%Y-%m-%d %H:%M:%S')) < 0) { $this->access_token = ''; if($this->debug) $this->OutputDebug('The OAuth access token expired in '.$this->access_token_expiry); } else { $this->access_token = $access_token['value']; if(IsSet($access_token['type'])) $this->access_token_type = $access_token['type']; else $this->access_token_type = ''; if($this->debug) $this->OutputDebug('The OAuth access token '.$this->access_token.' is valid'); if(strlen($this->access_token_type) && $this->debug) $this->OutputDebug('The OAuth access token is of type '.$this->access_token_type); if(IsSet($access_token['refresh'])) $this->refresh_token = $access_token['refresh']; else $this->refresh_token = ''; $valid = true; } } return true; } /* {metadocument} CallAPI BOOLEAN Send a HTTP request to the Web services API using a previously obtained authorization token via OAuth. This function can be used to call an API after having previously obtained an access token through the OAuth protocol using the Process function, or by directly setting the variables access_token, as well as access_token_secret in case of using OAuth 1.0 or 1.0a services. This function returns 1 if the call was done successfully. url STRING URL of the API where the HTTP request will be sent. method STRING HTTP method that will be used to send the request. It can be GET, POST, DELETE, PUT, etc.. parameters HASH Associative array with the names and values of the API call request parameters. options HASH Associative array with additional options to configure the request. Currently it supports the following options: 2Legged: boolean option that determines if the API request should be 2 legged. The default value is 0. Accept: content type value of the Accept HTTP header to be sent in the API call HTTP request. Some APIs require that a certain value be sent to specify which version of the API is being called. The default value is */*. ConvertObjects: boolean option that determines if objects should be converted into arrays when the response is returned in JSON format. The default value is 0. FailOnAccessError: boolean option that determines if this functions should fail when the server response status is not between 200 and 299. The default value is 0. Files: associative array with details of the parameters that must be passed as file uploads. The array indexes must have the same name of the parameters to be sent as files. The respective array entry values must also be associative arrays with the parameters for each file. Currently it supports the following parameters: - Type - defines how the parameter value should be treated. It can be 'FileName' if the parameter value is is the name of a local file to be uploaded. It may also be 'Data' if the parameter value is the actual data of the file to be uploaded. - Default: 'FileName' - ContentType - MIME value of the content type of the file. It can be 'automatic/name' if the content type should be determine from the file name extension. - Default: 'automatic/name' PostValuesInURI: boolean option to determine that a POST request should pass the request values in the URI. The default value is 0. FollowRedirection: limit number of times that HTTP response redirects will be followed. If it is set to 0, redirection responses fail in error. The default value is 0. RequestBody: request body data of a custom type. The RequestContentType option must be specified, so the RequestBody option is considered. RequestContentType: content type that should be used to send the request values. It can be either application/x-www-form-urlencoded for sending values like from Web forms, or application/json for sending the values encoded in JSON format. Other types are accepted if the RequestBody option is specified. The default value is application/x-www-form-urlencoded. RequestBody: request body data of a custom type. The RequestContentType option must be specified, so the RequestBody option is considered. Resource: string with a label that will be used in the error messages and debug log entries to identify what operation the request is performing. The default value is API call. ResponseContentType: content type that should be considered when decoding the API request response. This overrides the Content-Type header returned by the server. If the content type is application/x-www-form-urlencoded the function will parse the data returning an array of key-value pairs. If the content type is application/json the response will be decode as a JSON-encoded data type. Other content type values will make the function return the original response value as it was returned from the server. The default value for this option is to use what the server returned in the Content-Type header. response STRING Return the value of the API response. If the value is JSON encoded, this function will decode it and return the value converted to respective types. If the value is form encoded, this function will decode the response and return it as an array. Otherwise, the class will return the value as a string. {/metadocument} */ Function CallAPI($url, $method, $parameters, $options, &$response) { if(!IsSet($options['Resource'])) $options['Resource'] = 'API call'; if(!IsSet($options['ConvertObjects'])) $options['ConvertObjects'] = false; if(strlen($this->access_token) === 0) { if(!$this->RetrieveToken($valid)) return false; if(!$valid) return $this->SetError('the access token is not set to a valid value'); } switch(intval($this->oauth_version)) { case 1: $oauth = array( 'oauth_token'=>((IsSet($options['2Legged']) && $options['2Legged']) ? '' : $this->access_token) ); break; case 2: if(strlen($this->access_token_expiry) && strcmp($this->access_token_expiry, gmstrftime('%Y-%m-%d %H:%M:%S')) <= 0) { if(strlen($this->refresh_token) === 0) return($this->SetError('the access token expired and no refresh token is available')); if($this->debug) { $this->OutputDebug('The access token expired on '.$this->access_token_expiry); $this->OutputDebug('Refreshing the access token'); } if(!$this->ProcessToken(null, true)) return false; } $oauth = null; $url .= (strcspn($url, '?') < strlen($url) ? '&' : '?').'access_token='.UrlEncode($this->access_token); break; default: return($this->SetError($this->oauth_version.' is not a supported version of the OAuth protocol')); } return($this->SendAPIRequest($url, $method, $parameters, $oauth, $options, $response)); } /* {metadocument} {/metadocument} */ /* {metadocument} Initialize BOOLEAN Initialize the class variables and internal state. It must be called before calling other class functions. Set the server variable before calling this function to let it initialize the class variables to work with the specified server type. Alternatively, you can set other class variables manually to make it work with servers that are not yet built-in supported. This function returns 1 if it was able to successfully initialize the class for the specified server type. {/metadocument} */ Function Initialize() { if(strlen($this->server) === 0) return true; $this->request_token_url = ''; $this->append_state_to_redirect_uri = ''; $this->authorization_header = true; $this->url_parameters = false; $this->token_request_method = 'GET'; $this->signature_method = 'HMAC-SHA1'; switch($this->server) { case 'Bitbucket': $this->oauth_version = '1.0a'; $this->request_token_url = 'https://bitbucket.org/!api/1.0/oauth/request_token'; $this->dialog_url = 'https://bitbucket.org/!api/1.0/oauth/authenticate'; $this->access_token_url = 'https://bitbucket.org/!api/1.0/oauth/access_token'; $this->url_parameters = true; break; case 'Box': $this->oauth_version = '2.0'; $this->dialog_url = 'https://www.box.com/api/oauth2/authorize?response_type=code&client_id={CLIENT_ID}&redirect_uri={REDIRECT_URI}&state={STATE}'; $this->offline_dialog_url = 'https://www.box.com/api/oauth2/authorize?response_type=code&client_id={CLIENT_ID}&redirect_uri={REDIRECT_URI}&state={STATE}&access_type=offline&approval_prompt=force'; $this->access_token_url = 'https://www.box.com/api/oauth2/token'; break; case 'Dropbox': $this->oauth_version = '1.0'; $this->request_token_url = 'https://api.dropbox.com/1/oauth/request_token'; $this->dialog_url = 'https://www.dropbox.com/1/oauth/authorize'; $this->access_token_url = 'https://api.dropbox.com/1/oauth/access_token'; $this->authorization_header = false; break; case 'Eventful': $this->oauth_version = '1.0a'; $this->request_token_url = 'http://eventful.com/oauth/request_token'; $this->dialog_url = 'http://eventful.com/oauth/authorize'; $this->access_token_url = 'http://eventful.com/oauth/access_token'; $this->authorization_header = false; $this->url_parameters = true; $this->token_request_method = 'POST'; break; case 'Evernote': $this->oauth_version = '1.0a'; $this->request_token_url = 'https://sandbox.evernote.com/oauth'; $this->dialog_url = 'https://sandbox.evernote.com/OAuth.action'; $this->access_token_url = 'https://sandbox.evernote.com/oauth'; $this->url_parameters = true; $this->authorization_header = false; break; case 'Facebook': $this->oauth_version = '2.0'; $this->dialog_url = 'https://www.facebook.com/dialog/oauth?client_id={CLIENT_ID}&redirect_uri={REDIRECT_URI}&scope={SCOPE}&state={STATE}'; $this->access_token_url = 'https://graph.facebook.com/oauth/access_token'; break; case 'Fitbit': $this->oauth_version = '1.0a'; $this->request_token_url = 'http://api.fitbit.com/oauth/request_token'; $this->dialog_url = 'http://api.fitbit.com/oauth/authorize'; $this->access_token_url = 'http://api.fitbit.com/oauth/access_token'; break; case 'Flickr': $this->oauth_version = '1.0a'; $this->request_token_url = 'http://www.flickr.com/services/oauth/request_token'; $this->dialog_url = 'http://www.flickr.com/services/oauth/authorize?perms={SCOPE}'; $this->access_token_url = 'http://www.flickr.com/services/oauth/access_token'; $this->authorization_header = false; break; case 'Foursquare': $this->oauth_version = '2.0'; $this->dialog_url = 'https://foursquare.com/oauth2/authorize?client_id={CLIENT_ID}&scope={SCOPE}&response_type=code&redirect_uri={REDIRECT_URI}&state={STATE}'; $this->access_token_url = 'https://foursquare.com/oauth2/access_token'; break; case 'github': $this->oauth_version = '2.0'; $this->dialog_url = 'https://github.com/login/oauth/authorize?client_id={CLIENT_ID}&redirect_uri={REDIRECT_URI}&scope={SCOPE}&state={STATE}'; $this->access_token_url = 'https://github.com/login/oauth/access_token'; break; case 'Google': $this->oauth_version = '2.0'; $this->dialog_url = 'https://accounts.google.com/o/oauth2/auth?response_type=code&client_id={CLIENT_ID}&redirect_uri={REDIRECT_URI}&scope={SCOPE}&state={STATE}'; $this->offline_dialog_url = 'https://accounts.google.com/o/oauth2/auth?response_type=code&client_id={CLIENT_ID}&redirect_uri={REDIRECT_URI}&scope={SCOPE}&state={STATE}&access_type=offline&approval_prompt=force'; $this->access_token_url = 'https://accounts.google.com/o/oauth2/token'; break; case 'Instagram': $this->oauth_version = '2.0'; $this->dialog_url ='https://api.instagram.com/oauth/authorize/?client_id={CLIENT_ID}&redirect_uri={REDIRECT_URI}&scope={SCOPE}&response_type=code&state={STATE}'; $this->access_token_url = 'https://api.instagram.com/oauth/access_token'; break; case 'LinkedIn': $this->oauth_version = '1.0a'; $this->request_token_url = 'https://api.linkedin.com/uas/oauth/requestToken?scope={SCOPE}'; $this->dialog_url = 'https://api.linkedin.com/uas/oauth/authenticate'; $this->access_token_url = 'https://api.linkedin.com/uas/oauth/accessToken'; $this->url_parameters = true; break; case 'Microsoft': $this->oauth_version = '2.0'; $this->dialog_url = 'https://login.live.com/oauth20_authorize.srf?client_id={CLIENT_ID}&scope={SCOPE}&response_type=code&redirect_uri={REDIRECT_URI}&state={STATE}'; $this->access_token_url = 'https://login.live.com/oauth20_token.srf'; break; case 'RightSignature': $this->oauth_version = '1.0a'; $this->request_token_url = 'https://rightsignature.com/oauth/request_token'; $this->dialog_url = 'https://rightsignature.com/oauth/authorize'; $this->access_token_url = 'https://rightsignature.com/oauth/access_token'; $this->authorization_header = false; break; case 'Scoop.it': $this->oauth_version = '1.0a'; $this->request_token_url = 'https://www.scoop.it/oauth/request'; $this->dialog_url = 'https://www.scoop.it/oauth/authorize'; $this->access_token_url = 'https://www.scoop.it/oauth/access'; $this->authorization_header = false; break; case 'StockTwits': $this->oauth_version = '2.0'; $this->dialog_url = 'https://api.stocktwits.com/api/2/oauth/authorize?client_id={CLIENT_ID}&response_type=code&redirect_uri={REDIRECT_URI}&scope={SCOPE}&state={STATE}'; $this->access_token_url = 'https://api.stocktwits.com/api/2/oauth/token'; break; case 'Tumblr': $this->oauth_version = '1.0a'; $this->request_token_url = 'http://www.tumblr.com/oauth/request_token'; $this->dialog_url = 'http://www.tumblr.com/oauth/authorize'; $this->access_token_url = 'http://www.tumblr.com/oauth/access_token'; break; case 'Twitter': $this->oauth_version = '1.0a'; $this->request_token_url = 'https://api.twitter.com/oauth/request_token'; $this->dialog_url = 'https://api.twitter.com/oauth/authenticate'; $this->access_token_url = 'https://api.twitter.com/oauth/access_token'; $this->url_parameters = true; break; case 'XING': $this->oauth_version = '1.0a'; $this->request_token_url = 'https://api.xing.com/v1/request_token'; $this->dialog_url = 'https://api.xing.com/v1/authorize'; $this->access_token_url = 'https://api.xing.com/v1/access_token'; $this->authorization_header = false; break; case 'Yahoo': $this->oauth_version = '1.0a'; $this->request_token_url = 'https://api.login.yahoo.com/oauth/v2/get_request_token'; $this->dialog_url = 'https://api.login.yahoo.com/oauth/v2/request_auth'; $this->access_token_url = 'https://api.login.yahoo.com/oauth/v2/get_token'; $this->authorization_header = false; break; default: return($this->SetError($this->server.' is not yet a supported type of OAuth server. Please contact the author Manuel Lemos to request adding built-in support to this type of OAuth server.')); } return(true); } /* {metadocument} {/metadocument} */ /* {metadocument} Process BOOLEAN Process the OAuth protocol interaction with the OAuth server. Call this function when you need to retrieve the OAuth access token. Check the access_token to determine if the access token was obtained successfully. This function returns 1 if the OAuth protocol was processed without errors. {/metadocument} */ Function Process() { switch(intval($this->oauth_version)) { case 1: $one_a = ($this->oauth_version === '1.0a'); if($this->debug) $this->OutputDebug('Checking the OAuth token authorization state'); if(!$this->GetAccessToken($access_token)) return false; if(IsSet($access_token['authorized']) && IsSet($access_token['value'])) { $expired = (IsSet($access_token['expiry']) && strcmp($access_token['expiry'], gmstrftime('%Y-%m-%d %H:%M:%S')) <= 0); if(!$access_token['authorized'] || $expired) { if($this->debug) { if($expired) $this->OutputDebug('The OAuth token expired on '.$access_token['expiry'].'UTC'); else $this->OutputDebug('The OAuth token is not yet authorized'); $this->OutputDebug('Checking the OAuth token and verifier'); } if(!$this->GetRequestToken($token, $verifier)) return false; if(!IsSet($token) || ($one_a && !IsSet($verifier))) { if(!$this->GetRequestDenied($denied)) return false; if(IsSet($denied) && $denied === $access_token['value']) { if($this->debug) $this->OutputDebug('The authorization request was denied'); $this->authorization_error = 'the request was denied'; return true; } else { if($this->debug) $this->OutputDebug('Reset the OAuth token state because token and verifier are not both set'); $access_token = array(); } } elseif($token !== $access_token['value']) { if($this->debug) $this->OutputDebug('Reset the OAuth token state because token does not match what as previously retrieved'); $access_token = array(); } else { if(!$this->GetAccessTokenURL($url)) return false; $oauth = array( 'oauth_token'=>$token, ); if($one_a) $oauth['oauth_verifier'] = $verifier; $this->access_token_secret = $access_token['secret']; $options = array('Resource'=>'OAuth access token'); $method = strtoupper($this->token_request_method); switch($method) { case 'GET': break; case 'POST': $options['PostValuesInURI'] = true; break; default: $this->error = $method.' is not a supported method to request tokens'; break; } if(!$this->SendAPIRequest($url, $method, array(), $oauth, $options, $response)) return false; if(strlen($this->access_token_error)) { $this->authorization_error = $this->access_token_error; return true; } if(!IsSet($response['oauth_token']) || !IsSet($response['oauth_token_secret'])) { $this->authorization_error= 'it was not returned the access token and secret'; return true; } $access_token = array( 'value'=>$response['oauth_token'], 'secret'=>$response['oauth_token_secret'], 'authorized'=>true ); if(IsSet($response['oauth_expires_in'])) { $expires = $response['oauth_expires_in']; if(strval($expires) !== strval(intval($expires)) || $expires <= 0) return($this->SetError('OAuth server did not return a supported type of access token expiry time')); $this->access_token_expiry = gmstrftime('%Y-%m-%d %H:%M:%S', time() + $expires); if($this->debug) $this->OutputDebug('Access token expiry: '.$this->access_token_expiry.' UTC'); $access_token['expiry'] = $this->access_token_expiry; } else $this->access_token_expiry = ''; if(!$this->StoreAccessToken($access_token)) return false; if($this->debug) $this->OutputDebug('The OAuth token was authorized'); } } elseif($this->debug) $this->OutputDebug('The OAuth token was already authorized'); if(IsSet($access_token['authorized']) && $access_token['authorized']) { $this->access_token = $access_token['value']; $this->access_token_secret = $access_token['secret']; return true; } } else { if($this->debug) $this->OutputDebug('The OAuth access token is not set'); $access_token = array(); } if(!IsSet($access_token['authorized'])) { if($this->debug) $this->OutputDebug('Requesting the unauthorized OAuth token'); if(!$this->GetRequestTokenURL($url)) return false; $url = str_replace('{SCOPE}', UrlEncode($this->scope), $url); if(!$this->GetRedirectURI($redirect_uri)) return false; $oauth = array( 'oauth_callback'=>$redirect_uri, ); $options = array('Resource'=>'OAuth request token'); $method = strtoupper($this->token_request_method); switch($method) { case 'GET': break; case 'POST': $options['PostValuesInURI'] = true; break; default: $this->error = $method.' is not a supported method to request tokens'; break; } if(!$this->SendAPIRequest($url, $method, array(), $oauth, $options, $response)) return false; if(strlen($this->access_token_error)) { $this->authorization_error = $this->access_token_error; return true; } if(!IsSet($response['oauth_token']) || !IsSet($response['oauth_token_secret'])) { $this->authorization_error = 'it was not returned the requested token'; return true; } $access_token = array( 'value'=>$response['oauth_token'], 'secret'=>$response['oauth_token_secret'], 'authorized'=>false ); if(!$this->StoreAccessToken($access_token)) return false; } if(!$this->GetDialogURL($url)) return false; $url .= (strpos($url, '?') === false ? '?' : '&').'oauth_token='.$access_token['value']; if(!$one_a) { if(!$this->GetRedirectURI($redirect_uri)) return false; $url .= '&oauth_callback='.UrlEncode($redirect_uri); } if($this->debug) $this->OutputDebug('Redirecting to OAuth authorize page '.$url); Header('HTTP/1.0 302 OAuth Redirection'); Header('Location: '.$url); $this->exit = true; return true; case 2: if($this->debug) $this->OutputDebug('Checking if OAuth access token was already retrieved from '.$this->access_token_url); if(!$this->RetrieveToken($valid)) return false; if($valid) return true; if($this->debug) $this->OutputDebug('Checking the authentication state in URI '.$_SERVER['REQUEST_URI']); if(!$this->GetStoredState($stored_state)) return false; if(strlen($stored_state) == 0) return($this->SetError('it was not set the OAuth state')); if(!$this->GetRequestState($state)) return false; if($state === $stored_state) { if($this->debug) $this->OutputDebug('Checking the authentication code'); if(!$this->GetRequestCode($code)) return false; if(strlen($code) == 0) { if(!$this->GetRequestError($this->authorization_error)) return false; if(IsSet($this->authorization_error)) { if($this->debug) $this->OutputDebug('Authorization failed with error code '.$this->authorization_error); switch($this->authorization_error) { case 'invalid_request': case 'unauthorized_client': case 'access_denied': case 'unsupported_response_type': case 'invalid_scope': case 'server_error': case 'temporarily_unavailable': case 'user_denied': return true; default: return($this->SetError('it was returned an unknown OAuth error code')); } } return($this->SetError('it was not returned the OAuth dialog code')); } if(!$this->ProcessToken($code, false)) return false; } else { if(!$this->GetRedirectURI($redirect_uri)) return false; if(strlen($this->append_state_to_redirect_uri)) $redirect_uri .= (strpos($redirect_uri, '?') === false ? '?' : '&').$this->append_state_to_redirect_uri.'='.$stored_state; if(!$this->GetDialogURL($url, $redirect_uri, $stored_state)) return false; if(strlen($url) == 0) return($this->SetError('it was not set the OAuth dialog URL')); if($this->debug) $this->OutputDebug('Redirecting to OAuth Dialog '.$url); Header('HTTP/1.0 302 OAuth Redirection'); Header('Location: '.$url); $this->exit = true; } break; default: return($this->SetError($this->oauth_version.' is not a supported version of the OAuth protocol')); } return(true); } /* {metadocument} {/metadocument} */ /* {metadocument} Finalize BOOLEAN Cleanup any resources that may have been used during the OAuth protocol processing or execution of API calls. Always call this function as the last step after calling the functions Process or CallAPI. This function returns 1 if the function cleaned up any resources successfully. success BOOLEAN Pass the last success state returned by the class or any external code processing the class function results. {/metadocument} */ Function Finalize($success) { return($success); } /* {metadocument} {/metadocument} */ /* {metadocument} Output VOID Display the results of the OAuth protocol processing. Only call this function if you are debugging the OAuth authorization process and you need to view what was its results. {/metadocument} */ Function Output() { if(strlen($this->authorization_error) || strlen($this->access_token_error) || strlen($this->access_token)) { ?> OAuth client result

OAuth client result

authorization_error)) { ?>

It was not possible to authorize the application.debug) { ?>
Authorization error: authorization_error); } ?>

access_token_error)) { ?>

It was not possible to use the application access token. debug) { ?>
Error: access_token_error); } ?>

access_token)) { ?>

The application authorization was obtained successfully. debug) { ?>
Access token: access_token); if(IsSet($this->access_token_secret)) { ?>
Access token secret: access_token_secret); } } ?>

access_token_expiry)) { ?>

Access token expiry: access_token_expiry; ?> UTC

{/metadocument} */ }; /* {metadocument} {/metadocument} */ ?>