updraftplus / includes / Dropbox / OAuth / Consumer / ConsumerAbstract.php

ConsumerAbstract.php in UpdraftPlus: WP Backup & Migration Plugin 1.3.8, at includes/Dropbox/OAuth/Consumer/ConsumerAbstract.php

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1	<?php
2
3	/**
4	* Abstract OAuth consumer
5	* @author Ben Tadiar <ben@handcraftedbyben.co.uk>
6	* @link https://github.com/benthedesigner/dropbox
7	* @package Dropbox\OAuth
8	* @subpackage Consumer
9	*/
10
11	abstract class Dropbox_ConsumerAbstract
12	{
13	// Dropbox web endpoint
14	const WEB_URL = 'https://www.dropbox.com/1/';
15
16	// OAuth flow methods
17	const REQUEST_TOKEN_METHOD = 'oauth/request_token';
18	const AUTHORISE_METHOD = 'oauth/authorize';
19	const ACCESS_TOKEN_METHOD = 'oauth/access_token';
20
21	/**
22	* Signature method, either PLAINTEXT or HMAC-SHA1
23	* @var string
24	*/
25	private $sigMethod = 'PLAINTEXT';
26
27	/**
28	* Output file handle
29	* @var null\|resource
30	*/
31	protected $outFile = null;
32
33	/**
34	* Input file handle
35	* @var null\|resource
36	*/
37	protected $inFile = null;
38
39	/**
40	* Authenticate using 3-legged OAuth flow, firstly
41	* checking we don't already have tokens to use
42	* @return void
43	*/
44	protected function authenticate()
45	{
46	if ((!$this->storage->get('access_token'))) {
47	try {
48	$this->getAccessToken();
49	} catch(Dropbox_Exception $e) {
50	$this->getRequestToken();
51	$this->authorise();
52	}
53	}
54	}
55
56	/**
57	* Acquire an unauthorised request token
58	* @link http://tools.ietf.org/html/rfc5849#section-2.1
59	* @return void
60	*/
61	private function getRequestToken()
62	{
63	// Nullify any request token we already have
64	$this->storage->set(null, 'request_token');
65	$url = Dropbox_API::API_URL . self::REQUEST_TOKEN_METHOD;
66	$response = $this->fetch('POST', $url, '');
67	$token = $this->parseTokenString($response['body']);
68	$this->storage->set($token, 'request_token');
69	}
70
71	/**
72	* Obtain user authorisation
73	* The user will be redirected to Dropbox' web endpoint
74	* @link http://tools.ietf.org/html/rfc5849#section-2.2
75	* @return void
76	*/
77	private function authorise()
78	{
79	// Only redirect if using CLI
80	if (PHP_SAPI !== 'cli') {
81	$url = $this->getAuthoriseUrl();
82	header('Location: ' . $url);
83	exit;
84	}
85	}
86
87	/**
88	* Build the user authorisation URL
89	* @return string
90	*/
91	public function getAuthoriseUrl()
92	{
93	// Get the request token
94	$token = $this->getToken();
95
96	// Prepare request parameters
97	$params = array(
98	'oauth_token' => $token->oauth_token,
99	'oauth_token_secret' => $token->oauth_token_secret,
100	'oauth_callback' => $this->callback,
101	);
102
103	// Build the URL and redirect the user
104	$query = '?' . http_build_query($params, '', '&');
105	$url = self::WEB_URL . self::AUTHORISE_METHOD . $query;
106	return $url;
107	}
108
109	/**
110	* Acquire an access token
111	* Tokens acquired at this point should be stored to
112	* prevent having to request new tokens for each API call
113	* @link http://tools.ietf.org/html/rfc5849#section-2.3
114	*/
115	public function getAccessToken()
116	{
117	// Get the signed request URL
118	$response = $this->fetch('POST', Dropbox_API::API_URL, self::ACCESS_TOKEN_METHOD);
119	$token = $this->parseTokenString($response['body']);
120	$this->storage->set($token, 'access_token');
121	}
122
123	/**
124	* Get the request/access token
125	* This will return the access/request token depending on
126	* which stage we are at in the OAuth flow, or a dummy object
127	* if we have not yet started the authentication process
128	* @return object stdClass
129	*/
130	private function getToken()
131	{
132	if (!$token = $this->storage->get('access_token')) {
133	if (!$token = $this->storage->get('request_token')) {
134	$token = new \stdClass();
135	$token->oauth_token = null;
136	$token->oauth_token_secret = null;
137	}
138	}
139	return $token;
140	}
141
142	/**
143	* Generate signed request URL
144	* See inline comments for description
145	* @link http://tools.ietf.org/html/rfc5849#section-3.4
146	* @param string $method HTTP request method
147	* @param string $url API endpoint to send the request to
148	* @param string $call API call to send
149	* @param array $additional Additional parameters as an associative array
150	* @return array
151	*/
152	protected function getSignedRequest($method, $url, $call, array $additional = array())
153	{
154	// Get the request/access token
155	$token = $this->getToken();
156
157	// Generate a random string for the request
158	$nonce = md5(microtime(true) . uniqid('', true));
159
160	// Prepare the standard request parameters
161	$params = array(
162	'oauth_consumer_key' => $this->consumerKey,
163	'oauth_token' => $token->oauth_token,
164	'oauth_signature_method' => $this->sigMethod,
165	'oauth_version' => '1.0',
166	// Generate nonce and timestamp if signature method is HMAC-SHA1
167	'oauth_timestamp' => ($this->sigMethod == 'HMAC-SHA1') ? time() : null,
168	'oauth_nonce' => ($this->sigMethod == 'HMAC-SHA1') ? $nonce : null,
169	);
170
171	// Merge with the additional request parameters
172	$params = array_merge($params, $additional);
173	ksort($params);
174
175	// URL encode each parameter to RFC3986 for use in the base string
176	$encoded = array();
177	foreach($params as $param => $value) {
178	if ($value !== null) {
179	// If the value is a file upload (prefixed with @), replace it with
180	// the destination filename, the file path will be sent in POSTFIELDS
181	if (isset($value[0]) && $value[0] === '@') $value = $params['filename'];
182	$encoded[] = $this->encode($param) . '=' . $this->encode($value);
183	} else {
184	unset($params[$param]);
185	}
186	}
187
188	// Build the first part of the string
189	$base = $method . '&' . $this->encode($url . $call) . '&';
190
191	// Re-encode the encoded parameter string and append to $base
192	$base .= $this->encode(implode('&', $encoded));
193
194	// Concatenate the secrets with an ampersand
195	$key = $this->consumerSecret . '&' . $token->oauth_token_secret;
196
197	// Get the signature string based on signature method
198	$signature = $this->getSignature($base, $key);
199	$params['oauth_signature'] = $signature;
200
201	// Build the signed request URL
202	$query = '?' . http_build_query($params, '', '&');
203
204	return array(
205	'url' => $url . $call . $query,
206	'postfields' => $params,
207	);
208	}
209
210	/**
211	* Generate the oauth_signature for a request
212	* @param string $base Signature base string, used by HMAC-SHA1
213	* @param string $key Concatenated consumer and token secrets
214	*/
215	private function getSignature($base, $key)
216	{
217	switch ($this->sigMethod) {
218	case 'PLAINTEXT':
219	$signature = $key;
220	break;
221	case 'HMAC-SHA1':
222	$signature = base64_encode(hash_hmac('sha1', $base, $key, true));
223	break;
224	}
225
226	return $signature;
227	}
228
229	/**
230	* Set the OAuth signature method
231	* @param string $method Either PLAINTEXT or HMAC-SHA1
232	* @return void
233	*/
234	public function setSignatureMethod($method)
235	{
236	$method = strtoupper($method);
237
238	switch ($method) {
239	case 'PLAINTEXT':
240	case 'HMAC-SHA1':
241	$this->sigMethod = $method;
242	break;
243	default:
244	throw new Dropbox_Exception('Unsupported signature method ' . $method);
245	}
246	}
247
248	/**
249	* Set the output file
250	* @param resource Resource to stream response data to
251	* @return void
252	*/
253	public function setOutFile($handle)
254	{
255	if (!is_resource($handle) \|\| get_resource_type($handle) != 'stream') {
256	throw new Dropbox_Exception('Outfile must be a stream resource');
257	}
258	$this->outFile = $handle;
259	}
260
261	/**
262	* Set the input file
263	* @param resource Resource to read data from
264	* @return void
265	*/
266	public function setInFile($handle)
267	{
268	if (!is_resource($handle) \|\| get_resource_type($handle) != 'stream') {
269	throw new Dropbox_Exception('Infile must be a stream resource');
270	}
271	fseek($handle, 0);
272	$this->inFile = $handle;
273	}
274
275	/**
276	* Parse response parameters for a token into an object
277	* Dropbox returns tokens in the response parameters, and
278	* not a JSON encoded object as per other API requests
279	* @link http://oauth.net/core/1.0/#response_parameters
280	* @param string $response
281	* @return object stdClass
282	*/
283	private function parseTokenString($response)
284	{
285	$parts = explode('&', $response);
286	$token = new \stdClass();
287	foreach ($parts as $part) {
288	list($k, $v) = explode('=', $part, 2);
289	$k = strtolower($k);
290	$token->$k = $v;
291	}
292	return $token;
293	}
294
295	/**
296	* Encode a value to RFC3986
297	* This is a convenience method to decode ~ symbols encoded
298	* by rawurldecode. This will encode all characters except
299	* the unreserved set, ALPHA, DIGIT, '-', '.', '_', '~'
300	* @link http://tools.ietf.org/html/rfc5849#section-3.6
301	* @param mixed $value
302	*/
303	private function encode($value)
304	{
305	return str_replace('%7E', '~', rawurlencode($value));
306	}
307	}
308