fileapi/drivers/s3.driver

<?php

/**
 * @file
 * Amazon S3 storage driver for filesystem.
 * 
 * We are treating S3 like a normal hierarchal filesystem. The bucket
 * is predetermined by the mountpoint settings. Except for list buckets 
 * and put bucket functions.
 *
 * We use the keys with a delimiter of '/' to create our heirarchy.
 *
 */


/**
 * driver settings form. called by fileapi.module when creating a respository using this driver.
 * @param $settings
 *   settings array from database.
 * @todo convert form to multistep to allow input of credentials, then bucket selection/creation.
 * @todo add bucket access control policy settings
 */

function fileapi_driver_s3_settings_form($settings = array()) {
  //debug_msg($settings);
  $form = array(
    '#type' => 'fieldset',
    '#title' => t('Amazon S3 storage driver settings'),
    '#tree' => TRUE,
  );

  $form['driver'] = array(
    '#type' => 'hidden',
    '#value' => 's3',
  );

  $form['s3 url'] = array(
    '#type' => 'textfield',
    '#title' => t('Amazon S3 url'),
    '#description' => t('The URL must not contain a trailing slash.'),
    '#default_value' => strlen($settings['s3 url']) ? $settings['s3 url'] : 'http://s3.amazonaws.com',
  );

  $form['awsID'] = array(
    '#type' => 'textfield',
    '#title' => t('AWS Access Key ID'),
    '#default_value' => $settings['awsID'],
  );

  $form['awsSecret'] = array(
    '#type' => 'textfield',
    '#title' => t('AWS Secret'),
    '#default_value' => $settings['awsSecret'],
  );

  $form['bucket'] = array(
    '#type' => 'textfield',
    '#title' => t('S3 Bucket'),
    '#default_value' => $settings['bucket'],
  );

  return $form;
} 

function fileapi_driver_s3_settings_form_validate() {
  //@todo test for trailing slash in 's3 url';
}

function fileapi_driver_s3_settings_form_submit() {
  //@todo create bucket if it doesn't exist.
}


/** 
 * test if a path is a file.
 *
 * for S3 we are going to operate on an object if an object
 * has the key we're requesting. 
 * see: S3 Developers Guide pg 67.
 *
 * @param $path
 *   path to be tested
 *
 */
function fileapi_driver_s3_is_file($settings, $path) {
  // request meta data for an object with the key $path.
  $result = s3_request('HEAD', $path, $settings);

  //parse results for request...
}

/** 
 * test if a path is a directory.
 * @param $path
 *   path to be tested
 */
function fileapi_driver_s3_is_dir($settings, $path) {
}


/**
 * create a directory using standard php functions
 * @param $path
 */
function fileapi_driver_s3_mkdir($settings, $path) {
  // there are technically no directories, so we can safely do 
  // nothing here.
  return TRUE;
}


/**
 * remove a directory using standard php functions
 * @param $path
 */

function fileapi_driver_s3_rmdir($settings, $path) {
  // there are technically no directories.
  // so we can test is there is a file in the 'directory' and return false here.
}


/**
 * remove a file using standard php functions
 * @param $path
 */
function fileapi_driver_s3_remove($settings, $path) {

}

/**
 * copy a file using standard php functions
 * @param $src
 * @param $dst
 */
function fileapi_driver_s3_copy($settings, $src, $dst) {

}

/**
 * move a file using standard php functions
 * @param $src
 * @param $dst
 */
function fileapi_driver_s3_move($settings, $src, $dst) {

}

/**
 * check if  a file exists using standard php functions
 * @param $path
 */
function fileapi_driver_s3_exists($settings, $path) {
}

/**
 * touch a path and create a file there.
 * @param $path 
 *    path to be touched.
 */
function fileapi_driver_s3_touch($settings, $path) {
  $tmp = file_directory_tmp() .'/'. basename($path);
  touch($tmp);
  $headers = array();
  $headers['Content-Type'] = 'text/plain';
  $body = file_get_contents($tmp);
  s3_request('PUT', $path, $settings, array(), $body);
  unlink($tmp);
}


/**
 * read the contents of a directory.
 * @param $path
 *   directory to be read.
 * @return  array
 *   action results and array of directory contents.
 */
function fileapi_driver_s3_readdir($settings, $path) {
  $result = s3_request('GET', $settings['bucket'] .'?delimiter=/&key=$path', $settings);
}  

/**
 * read the contents of a file.
 * @param $path 
 *   path of file to be read.
 *
 * NOTE: we are not including offset and maxlen since it is only supported in php > 5.1.0
 *       and our support target is 4.3.0.
 */
function fileapi_driver_s3_fileread($settings, $path) {
  $result = s3_request('GET', $path, $settings);
  return $result;
}

function fileapi_driver_s3_filewrite($settings, $path, $data) {
  $headers = array('Content-Type' => 'text/plain');
  $result = s3_request('PUT', $settings['bucket'] .'/'. $path, $settings, array(), $data);
  return $result;
}

function s3_request($method, $resource, $settings, $headers=array(), $amzheaders=array(),  $body=NULL) {
  
  $url = $settings['s3 url']; 

  // Set date to proper format for S3. 
  $headers['Date'] = gmdate(DATE_RFC822);
  $headers['Authorization'] = 'AWS '. $settings['awsID'] .':'. $signature; 

  // Build S3 authorization hash.
  $auth_string = $method ."\n\n". $headers['Content-type'] ."\n" . $headers['Date'] ."\n";
  if (count($amzheaders)) {
    $auth_string .= implode("\n",$amzheaders) ."\n";
  }
  $auth_string .= '/'. $resource;
  $signature = hex2b64(s3_hmac_sha1($settings['awsSecret'], $auth_string));
  print "auth_string:\n$auth_string\n"; 
  print "signature: $signature\n";

  // Set date to proper format for S3. 
  $headers['Date'] = gmdate(DATE_RFC822);
  $headers['Authorization'] = 'AWS '. $settings['awsID'] .':'. $signature; 

  $result = drupal_http_request($url .'/'. $resource, array_merge($headers, $amzheaders), $method, $body);
  return $result;
  // drupal_set_message('<pre>'. print_r($result, TRUE) .'</pre>');
  // @todo error handling.
}


/**
 * Generate an sha1 signed hash of a string.
 * @param K
 *    key to be used for the signature.
 * @param string
 *    string to be signed.
 */
function s3_hmac_sha1($K, $string) {
  // hash function
  $h = 'sha1';
  // byte length of blocks operated on by hash function.
  $B = '64';
  // byte length of hash function output.
  // seems unused in the HMAC algorithm
  $L = '20';
  return s3_hmac($h, $B, $K, $string);
}

/**
 * HMAC implementation for drupal as per
 * http://www.ietf.org/rfc/rfc2104.txt
 * 
 * @param $h
 *   hashing function can be any 
 * @param $B
 *   block length iterated over by hashing algorithm
 * @param $K
 *   key to be used for signing.
 * @param $string
 *   string to be signed.
 */
function s3_hmac($h, $B, $K, $string) {
  // Hash the key if it exceeds the blocklength.
  if (strlen($K) > $B) {
    // Pack that dirty string.
    $K = pack('H*', $h($K));
  }
  // pad it with 0 bytes to block length
  $K = str_pad($K, $B, chr(0x00));

  // Setup inner and outer pads as per the RFC.
  $ipad = str_repeat(chr(0x36), $B)^$K;
  $opad = str_repeat(chr(0x5C), $B)^$K;

  // Do inner concat XOR hashing. Pack that dirty string.
  $string =  pack('H*', $h($ipad.$string));

  // return outer concat XOR hash 
  return $h($opad.$string);
}

// conversion.
function hex2b64($str)
{
    $raw = '';
    for ($i=0; $i < strlen($str); $i+=2)
    {
        $raw .= chr(hexdec(substr($str, $i, 2)));
    }
    return base64_encode($raw);
}

1	<?php
2
3	/**
4	* @file
5	* Amazon S3 storage driver for filesystem.
6	*
7	* We are treating S3 like a normal hierarchal filesystem. The bucket
8	* is predetermined by the mountpoint settings. Except for list buckets
9	* and put bucket functions.
10	*
11	* We use the keys with a delimiter of '/' to create our heirarchy.
12	*
13	*/
14
15
16	/**
17	* driver settings form. called by fileapi.module when creating a respository using this driver.
18	* @param $settings
19	* settings array from database.
20	* @todo convert form to multistep to allow input of credentials, then bucket selection/creation.
21	* @todo add bucket access control policy settings
22	*/
23
24	function fileapi_driver_s3_settings_form($settings = array()) {
25	//debug_msg($settings);
26	$form = array(
27	'#type' => 'fieldset',
28	'#title' => t('Amazon S3 storage driver settings'),
29	'#tree' => TRUE,
30	);
31
32	$form['driver'] = array(
33	'#type' => 'hidden',
34	'#value' => 's3',
35	);
36
37	$form['s3 url'] = array(
38	'#type' => 'textfield',
39	'#title' => t('Amazon S3 url'),
40	'#description' => t('The URL must not contain a trailing slash.'),
41	'#default_value' => strlen($settings['s3 url']) ? $settings['s3 url'] : 'http://s3.amazonaws.com',
42	);
43
44	$form['awsID'] = array(
45	'#type' => 'textfield',
46	'#title' => t('AWS Access Key ID'),
47	'#default_value' => $settings['awsID'],
48	);
49
50	$form['awsSecret'] = array(
51	'#type' => 'textfield',
52	'#title' => t('AWS Secret'),
53	'#default_value' => $settings['awsSecret'],
54	);
55
56	$form['bucket'] = array(
57	'#type' => 'textfield',
58	'#title' => t('S3 Bucket'),
59	'#default_value' => $settings['bucket'],
60	);
61
62	return $form;
63	}
64
65	function fileapi_driver_s3_settings_form_validate() {
66	//@todo test for trailing slash in 's3 url';
67	}
68
69	function fileapi_driver_s3_settings_form_submit() {
70	//@todo create bucket if it doesn't exist.
71	}
72
73
74	/**
75	* test if a path is a file.
76	*
77	* for S3 we are going to operate on an object if an object
78	* has the key we're requesting.
79	* see: S3 Developers Guide pg 67.
80	*
81	* @param $path
82	* path to be tested
83	*
84	*/
85	function fileapi_driver_s3_is_file($settings, $path) {
86	// request meta data for an object with the key $path.
87	$result = s3_request('HEAD', $path, $settings);
88
89	//parse results for request...
90	}
91
92	/**
93	* test if a path is a directory.
94	* @param $path
95	* path to be tested
96	*/
97	function fileapi_driver_s3_is_dir($settings, $path) {
98	}
99
100
101	/**
102	* create a directory using standard php functions
103	* @param $path
104	*/
105	function fileapi_driver_s3_mkdir($settings, $path) {
106	// there are technically no directories, so we can safely do
107	// nothing here.
108	return TRUE;
109	}
110
111
112	/**
113	* remove a directory using standard php functions
114	* @param $path
115	*/
116
117	function fileapi_driver_s3_rmdir($settings, $path) {
118	// there are technically no directories.
119	// so we can test is there is a file in the 'directory' and return false here.
120	}
121
122
123	/**
124	* remove a file using standard php functions
125	* @param $path
126	*/
127	function fileapi_driver_s3_remove($settings, $path) {
128
129	}
130
131	/**
132	* copy a file using standard php functions
133	* @param $src
134	* @param $dst
135	*/
136	function fileapi_driver_s3_copy($settings, $src, $dst) {
137
138	}
139
140	/**
141	* move a file using standard php functions
142	* @param $src
143	* @param $dst
144	*/
145	function fileapi_driver_s3_move($settings, $src, $dst) {
146
147	}
148
149	/**
150	* check if a file exists using standard php functions
151	* @param $path
152	*/
153	function fileapi_driver_s3_exists($settings, $path) {
154	}
155
156	/**
157	* touch a path and create a file there.
158	* @param $path
159	* path to be touched.
160	*/
161	function fileapi_driver_s3_touch($settings, $path) {
162	$tmp = file_directory_tmp() .'/'. basename($path);
163	touch($tmp);
164	$headers = array();
165	$headers['Content-Type'] = 'text/plain';
166	$body = file_get_contents($tmp);
167	s3_request('PUT', $path, $settings, array(), $body);
168	unlink($tmp);
169	}
170
171
172	/**
173	* read the contents of a directory.
174	* @param $path
175	* directory to be read.
176	* @return array
177	* action results and array of directory contents.
178	*/
179	function fileapi_driver_s3_readdir($settings, $path) {
180	$result = s3_request('GET', $settings['bucket'] .'?delimiter=/&key=$path', $settings);
181	}
182
183	/**
184	* read the contents of a file.
185	* @param $path
186	* path of file to be read.
187	*
188	* NOTE: we are not including offset and maxlen since it is only supported in php > 5.1.0
189	* and our support target is 4.3.0.
190	*/
191	function fileapi_driver_s3_fileread($settings, $path) {
192	$result = s3_request('GET', $path, $settings);
193	return $result;
194	}
195
196	function fileapi_driver_s3_filewrite($settings, $path, $data) {
197	$headers = array('Content-Type' => 'text/plain');
198	$result = s3_request('PUT', $settings['bucket'] .'/'. $path, $settings, array(), $data);
199	return $result;
200	}
201
202	function s3_request($method, $resource, $settings, $headers=array(), $amzheaders=array(), $body=NULL) {
203
204	$url = $settings['s3 url'];
205
206	// Set date to proper format for S3.
207	$headers['Date'] = gmdate(DATE_RFC822);
208	$headers['Authorization'] = 'AWS '. $settings['awsID'] .':'. $signature;
209
210	// Build S3 authorization hash.
211	$auth_string = $method ."\n\n". $headers['Content-type'] ."\n" . $headers['Date'] ."\n";
212	if (count($amzheaders)) {
213	$auth_string .= implode("\n",$amzheaders) ."\n";
214	}
215	$auth_string .= '/'. $resource;
216	$signature = hex2b64(s3_hmac_sha1($settings['awsSecret'], $auth_string));
217	print "auth_string:\n$auth_string\n";
218	print "signature: $signature\n";
219
220	// Set date to proper format for S3.
221	$headers['Date'] = gmdate(DATE_RFC822);
222	$headers['Authorization'] = 'AWS '. $settings['awsID'] .':'. $signature;
223
224	$result = drupal_http_request($url .'/'. $resource, array_merge($headers, $amzheaders), $method, $body);
225	return $result;
226	// drupal_set_message('<pre>'. print_r($result, TRUE) .'</pre>');
227	// @todo error handling.
228	}
229
230
231	/**
232	* Generate an sha1 signed hash of a string.
233	* @param K
234	* key to be used for the signature.
235	* @param string
236	* string to be signed.
237	*/
238	function s3_hmac_sha1($K, $string) {
239	// hash function
240	$h = 'sha1';
241	// byte length of blocks operated on by hash function.
242	$B = '64';
243	// byte length of hash function output.
244	// seems unused in the HMAC algorithm
245	$L = '20';
246	return s3_hmac($h, $B, $K, $string);
247	}
248
249	/**
250	* HMAC implementation for drupal as per
251	* http://www.ietf.org/rfc/rfc2104.txt
252	*
253	* @param $h
254	* hashing function can be any
255	* @param $B
256	* block length iterated over by hashing algorithm
257	* @param $K
258	* key to be used for signing.
259	* @param $string
260	* string to be signed.
261	*/
262	function s3_hmac($h, $B, $K, $string) {
263	// Hash the key if it exceeds the blocklength.
264	if (strlen($K) > $B) {
265	// Pack that dirty string.
266	$K = pack('H*', $h($K));
267	}
268	// pad it with 0 bytes to block length
269	$K = str_pad($K, $B, chr(0x00));
270
271	// Setup inner and outer pads as per the RFC.
272	$ipad = str_repeat(chr(0x36), $B)^$K;
273	$opad = str_repeat(chr(0x5C), $B)^$K;
274
275	// Do inner concat XOR hashing. Pack that dirty string.
276	$string = pack('H*', $h($ipad.$string));
277
278	// return outer concat XOR hash
279	return $h($opad.$string);
280	}
281
282	// conversion.
283	function hex2b64($str)
284	{
285	$raw = '';
286	for ($i=0; $i < strlen($str); $i+=2)
287	{
288	$raw .= chr(hexdec(substr($str, $i, 2)));
289	}
290	return base64_encode($raw);
291	}
292