media-cloud-sync / includes / sdk / s3 / Aws / Signature / SignatureProvider.php

SignatureProvider.php in Media Cloud Sync 1.2.2, at includes/sdk/s3/Aws/Signature/SignatureProvider.php

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1	<?php
2
3	namespace Dudlewebs\WPMCS\s3\Aws\Signature;
4
5	use Dudlewebs\WPMCS\s3\Aws\Exception\UnresolvedSignatureException;
6	/**
7	* Signature providers.
8	*
9	* A signature provider is a function that accepts a version, service, and
10	* region and returns a {@see SignatureInterface} object on success or NULL if
11	* no signature can be created from the provided arguments.
12	*
13	* You can wrap your calls to a signature provider with the
14	* {@see SignatureProvider::resolve} function to ensure that a signature object
15	* is created. If a signature object is not created, then the resolve()
16	* function will throw a {@see Aws\Exception\UnresolvedSignatureException}.
17	*
18	* use Aws\Signature\SignatureProvider;
19	* $provider = SignatureProvider::defaultProvider();
20	* // Returns a SignatureInterface or NULL.
21	* $signer = $provider('v4', 's3', 'us-west-2');
22	* // Returns a SignatureInterface or throws.
23	* $signer = SignatureProvider::resolve($provider, 'no', 's3', 'foo');
24	*
25	* You can compose multiple providers into a single provider using
26	* {@see Aws\or_chain}. This function accepts providers as arguments and
27	* returns a new function that will invoke each provider until a non-null value
28	* is returned.
29	*
30	* $a = SignatureProvider::defaultProvider();
31	* $b = function ($version, $service, $region) {
32	* if ($version === 'foo') {
33	* return new MyFooSignature();
34	* }
35	* };
36	* $c = \Aws\or_chain($a, $b);
37	* $signer = $c('v4', 'abc', '123'); // $a handles this.
38	* $signer = $c('foo', 'abc', '123'); // $b handles this.
39	* $nullValue = $c('???', 'abc', '123'); // Neither can handle this.
40	*/
41	class SignatureProvider
42	{
43	private static $s3v4SignedServices = ['s3' => \true, 's3control' => \true, 's3-object-lambda' => \true];
44	/**
45	* Resolves and signature provider and ensures a non-null return value.
46	*
47	* @param callable $provider Provider function to invoke.
48	* @param string $version Signature version.
49	* @param string $service Service name.
50	* @param string $region Region name.
51	*
52	* @return SignatureInterface
53	* @throws UnresolvedSignatureException
54	*/
55	public static function resolve(callable $provider, $version, $service, $region)
56	{
57	$result = $provider($version, $service, $region);
58	if ($result instanceof SignatureInterface) {
59	return $result;
60	}
61	throw new UnresolvedSignatureException("Unable to resolve a signature for {$version}/{$service}/{$region}.\n" . "Valid signature versions include v4 and anonymous.");
62	}
63	/**
64	* Default SDK signature provider.
65	*
66	* @return callable
67	*/
68	public static function defaultProvider()
69	{
70	return self::memoize(self::version());
71	}
72	/**
73	* Creates a signature provider that caches previously created signature
74	* objects. The computed cache key is the concatenation of the version,
75	* service, and region.
76	*
77	* @param callable $provider Signature provider to wrap.
78	*
79	* @return callable
80	*/
81	public static function memoize(callable $provider)
82	{
83	$cache = [];
84	return function ($version, $service, $region) use(&$cache, $provider) {
85	$key = "({$version})({$service})({$region})";
86	if (!isset($cache[$key])) {
87	$cache[$key] = $provider($version, $service, $region);
88	}
89	return $cache[$key];
90	};
91	}
92	/**
93	* Creates signature objects from known signature versions.
94	*
95	* This provider currently recognizes the following signature versions:
96	*
97	* - v4: Signature version 4.
98	* - anonymous: Does not sign requests.
99	*
100	* @return callable
101	*/
102	public static function version()
103	{
104	return function ($version, $service, $region) {
105	switch ($version) {
106	case 's3v4':
107	case 'v4':
108	return !empty(self::$s3v4SignedServices[$service]) ? new S3SignatureV4($service, $region) : new SignatureV4($service, $region);
109	case 'v4a':
110	return new SignatureV4($service, $region, ['use_v4a' => \true]);
111	case 'v4-unsigned-body':
112	return !empty(self::$s3v4SignedServices[$service]) ? new S3SignatureV4($service, $region, ['unsigned-body' => 'true']) : new SignatureV4($service, $region, ['unsigned-body' => 'true']);
113	case 'anonymous':
114	return new AnonymousSignature();
115	default:
116	return null;
117	}
118	};
119	}
120	}
121