nextcloud/lib/private/Files/ObjectStore/S3Signature.php

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<?php
/**
*
*
* @author Christoph Wurst <christoph@winzerhof-wurst.at>
* @author Daniel Kesselberg <mail@danielkesselberg.de>
* @author Robin Appelman <robin@icewind.nl>
*
* @license GNU AGPL version 3 or any later version
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
namespace OC\Files\ObjectStore;
use Aws\Credentials\CredentialsInterface;
use Aws\S3\S3Client;
use Aws\S3\S3UriParser;
use Aws\Signature\SignatureInterface;
use GuzzleHttp\Psr7;
use Psr\Http\Message\RequestInterface;
/**
* Legacy Amazon S3 signature implementation
*/
class S3Signature implements SignatureInterface {
/** @var array Query string values that must be signed */
private $signableQueryString = [
'acl', 'cors', 'delete', 'lifecycle', 'location', 'logging',
'notification', 'partNumber', 'policy', 'requestPayment',
'response-cache-control', 'response-content-disposition',
'response-content-encoding', 'response-content-language',
'response-content-type', 'response-expires', 'restore', 'tagging',
'torrent', 'uploadId', 'uploads', 'versionId', 'versioning',
'versions', 'website'
];
/** @var array Sorted headers that must be signed */
private $signableHeaders = ['Content-MD5', 'Content-Type'];
/** @var \Aws\S3\S3UriParser S3 URI parser */
private $parser;
public function __construct() {
$this->parser = new S3UriParser();
// Ensure that the signable query string parameters are sorted
sort($this->signableQueryString);
}
public function signRequest(
RequestInterface $request,
CredentialsInterface $credentials
) {
$request = $this->prepareRequest($request, $credentials);
$stringToSign = $this->createCanonicalizedString($request);
$auth = 'AWS '
. $credentials->getAccessKeyId() . ':'
. $this->signString($stringToSign, $credentials);
return $request->withHeader('Authorization', $auth);
}
public function presign(
RequestInterface $request,
CredentialsInterface $credentials,
$expires,
array $options = []
) {
$query = [];
// URL encoding already occurs in the URI template expansion. Undo that
// and encode using the same encoding as GET object, PUT object, etc.
$uri = $request->getUri();
$path = S3Client::encodeKey(rawurldecode($uri->getPath()));
$request = $request->withUri($uri->withPath($path));
// Make sure to handle temporary credentials
if ($token = $credentials->getSecurityToken()) {
$request = $request->withHeader('X-Amz-Security-Token', $token);
$query['X-Amz-Security-Token'] = $token;
}
if ($expires instanceof \DateTime) {
$expires = $expires->getTimestamp();
} elseif (!is_numeric($expires)) {
$expires = strtotime($expires);
}
// Set query params required for pre-signed URLs
$query['AWSAccessKeyId'] = $credentials->getAccessKeyId();
$query['Expires'] = $expires;
$query['Signature'] = $this->signString(
$this->createCanonicalizedString($request, $expires),
$credentials
);
// Move X-Amz-* headers to the query string
foreach ($request->getHeaders() as $name => $header) {
$name = strtolower($name);
if (strpos($name, 'x-amz-') === 0) {
$query[$name] = implode(',', $header);
}
}
$queryString = http_build_query($query, null, '&', PHP_QUERY_RFC3986);
return $request->withUri($request->getUri()->withQuery($queryString));
}
/**
* @param RequestInterface $request
* @param CredentialsInterface $creds
*
* @return RequestInterface
*/
private function prepareRequest(
RequestInterface $request,
CredentialsInterface $creds
) {
$modify = [
'remove_headers' => ['X-Amz-Date'],
'set_headers' => ['Date' => gmdate(\DateTime::RFC2822)]
];
// Add the security token header if one is being used by the credentials
if ($token = $creds->getSecurityToken()) {
$modify['set_headers']['X-Amz-Security-Token'] = $token;
}
return Psr7\modify_request($request, $modify);
}
private function signString($string, CredentialsInterface $credentials) {
return base64_encode(
hash_hmac('sha1', $string, $credentials->getSecretKey(), true)
);
}
private function createCanonicalizedString(
RequestInterface $request,
$expires = null
) {
$buffer = $request->getMethod() . "\n";
// Add the interesting headers
foreach ($this->signableHeaders as $header) {
$buffer .= $request->getHeaderLine($header) . "\n";
}
$date = $expires ?: $request->getHeaderLine('date');
$buffer .= "{$date}\n"
. $this->createCanonicalizedAmzHeaders($request)
. $this->createCanonicalizedResource($request);
return $buffer;
}
private function createCanonicalizedAmzHeaders(RequestInterface $request) {
$headers = [];
foreach ($request->getHeaders() as $name => $header) {
$name = strtolower($name);
if (strpos($name, 'x-amz-') === 0) {
$value = implode(',', $header);
if (strlen($value) > 0) {
$headers[$name] = $name . ':' . $value;
}
}
}
if (!$headers) {
return '';
}
ksort($headers);
return implode("\n", $headers) . "\n";
}
private function createCanonicalizedResource(RequestInterface $request) {
$data = $this->parser->parse($request->getUri());
$buffer = '/';
if ($data['bucket']) {
$buffer .= $data['bucket'];
if (!empty($data['key']) || !$data['path_style']) {
$buffer .= '/' . $data['key'];
}
}
// Add sub resource parameters if present.
$query = $request->getUri()->getQuery();
if ($query) {
$params = Psr7\parse_query($query);
$first = true;
foreach ($this->signableQueryString as $key) {
if (array_key_exists($key, $params)) {
$value = $params[$key];
$buffer .= $first ? '?' : '&';
$first = false;
$buffer .= $key;
// Don't add values for empty sub-resources
if (strlen($value)) {
$buffer .= "={$value}";
}
}
}
}
return $buffer;
}
}