media-cloud-sync / includes / sdk / s3 / Aws / Crypto / MaterialsProvider.php

MaterialsProvider.php in Media Cloud Sync 1.4.1, at includes/sdk/s3/Aws/Crypto/MaterialsProvider.php

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1	<?php
2
3	namespace Dudlewebs\WPMCS\s3\Aws\Crypto;
4
5	abstract class MaterialsProvider implements MaterialsProviderInterface
6	{
7	private static $supportedKeySizes = [128 => \true, 192 => \true, 256 => \true];
8	/**
9	* Returns if the requested size is supported by AES.
10	*
11	* @param int $keySize Size of the requested key in bits.
12	*
13	* @return bool
14	*/
15	public static function isSupportedKeySize($keySize)
16	{
17	return isset(self::$supportedKeySizes[$keySize]);
18	}
19	/**
20	* Performs further initialization of the MaterialsProvider based on the
21	* data inside the MetadataEnvelope.
22	*
23	* @param MetadataEnvelope $envelope A storage envelope for encryption
24	* metadata to be read from.
25	*
26	* @return MaterialsProvider
27	*
28	* @throws \RuntimeException Thrown when there is an empty or improperly
29	* formed materials description in the envelope.
30	*
31	* @internal
32	*/
33	public abstract function fromDecryptionEnvelope(MetadataEnvelope $envelope);
34	/**
35	* Returns the material description for this Provider so it can be verified
36	* by encryption mechanisms.
37	*
38	* @return string
39	*/
40	public abstract function getMaterialsDescription();
41	/**
42	* Returns the wrap algorithm name for this Provider.
43	*
44	* @return string
45	*/
46	public abstract function getWrapAlgorithmName();
47	/**
48	* Takes a content encryption key (CEK) and description to return an
49	* encrypted key according to the Provider's specifications.
50	*
51	* @param string $unencryptedCek Key for use in encrypting other data
52	* that itself needs to be encrypted by the
53	* Provider.
54	* @param string $materialDescription Material Description for use in
55	* encrypting the $cek.
56	*
57	* @return string
58	*/
59	public abstract function encryptCek($unencryptedCek, $materialDescription);
60	/**
61	* Takes an encrypted content encryption key (CEK) and material description
62	* for use decrypting the key according to the Provider's specifications.
63	*
64	* @param string $encryptedCek Encrypted key to be decrypted by the Provider
65	* for use decrypting other data.
66	* @param string $materialDescription Material Description for use in
67	* encrypting the $cek.
68	*
69	* @return string
70	*/
71	public abstract function decryptCek($encryptedCek, $materialDescription);
72	/**
73	* @param string $keySize Length of a cipher key in bits for generating a
74	* random content encryption key (CEK).
75	*
76	* @return string
77	*/
78	public function generateCek($keySize)
79	{
80	return \openssl_random_pseudo_bytes($keySize / 8);
81	}
82	/**
83	* @param string $openSslName Cipher OpenSSL name to use for generating
84	* an initialization vector.
85	*
86	* @return string
87	*/
88	public function generateIv($openSslName)
89	{
90	return \openssl_random_pseudo_bytes(\openssl_cipher_iv_length($openSslName));
91	}
92	}
93