spaces.php

aws/Aws/Crypto/AbstractCryptoClient.php

@@ -0,0 +1,138 @@
+<?php
+namespace Aws\Crypto;
+
+use Aws\Crypto\Cipher\CipherMethod;
+use Aws\Crypto\Cipher\Cbc;
+use GuzzleHttp\Psr7\Stream;
+
+/**
+ * @internal
+ */
+abstract class AbstractCryptoClient
+{
+    private static $supportedCiphers = ['cbc', 'gcm'];
+
+    /**
+     * Returns if the passed cipher name is supported for encryption by the SDK.
+     *
+     * @param string $cipherName The name of a cipher to verify is registered.
+     *
+     * @return bool If the cipher passed is in our supported list.
+     */
+    public static function isSupportedCipher($cipherName)
+    {
+        return in_array($cipherName, self::$supportedCiphers);
+    }
+
+    /**
+     * Returns an identifier recognizable by `openssl_*` functions, such as
+     * `aes-256-cbc` or `aes-128-ctr`.
+     *
+     * @param string $cipherName Name of the cipher being used for encrypting
+     *                           or decrypting.
+     * @param int $keySize Size of the encryption key, in bits, that will be
+     *                     used.
+     *
+     * @return string
+     */
+    protected function getCipherOpenSslName($cipherName, $keySize)
+    {
+        return "aes-{$keySize}-{$cipherName}";
+    }
+
+    /**
+     * Constructs a CipherMethod for the given name, initialized with the other
+     * data passed for use in encrypting or decrypting.
+     *
+     * @param string $cipherName Name of the cipher to generate for encrypting.
+     * @param string $iv Base Initialization Vector for the cipher.
+     * @param int $keySize Size of the encryption key, in bits, that will be
+     *                     used.
+     *
+     * @return CipherMethod
+     *
+     * @internal
+     */
+    protected function buildCipherMethod($cipherName, $iv, $keySize)
+    {
+        switch ($cipherName) {
+            case 'cbc':
+                return new Cbc(
+                    $iv,
+                    $keySize
+                );
+            default:
+                return null;
+        }
+    }
+
+    /**
+     * Performs a reverse lookup to get the openssl_* cipher name from the
+     * AESName passed in from the MetadataEnvelope.
+     *
+     * @param $aesName
+     *
+     * @return string
+     *
+     * @internal
+     */
+    protected function getCipherFromAesName($aesName)
+    {
+        switch ($aesName) {
+            case 'AES/GCM/NoPadding':
+                return 'gcm';
+            case 'AES/CBC/PKCS5Padding':
+                return 'cbc';
+            default:
+                throw new \RuntimeException('Unrecognized or unsupported'
+                    . ' AESName for reverse lookup.');
+        }
+    }
+
+    /**
+     * Dependency to provide an interface for building an encryption stream for
+     * data given cipher details, metadata, and materials to do so.
+     *
+     * @param Stream $plaintext Plain-text data to be encrypted using the
+     *                          materials, algorithm, and data provided.
+     * @param array $cipherOptions Options for use in determining the cipher to
+     *                             be used for encrypting data.
+     * @param MaterialsProvider $provider A provider to supply and encrypt
+     *                                    materials used in encryption.
+     * @param MetadataEnvelope $envelope A storage envelope for encryption
+     *                                   metadata to be added to.
+     *
+     * @return AesStreamInterface
+     *
+     * @internal
+     */
+    abstract public function encrypt(
+        Stream $plaintext,
+        array $cipherOptions,
+        MaterialsProvider $provider,
+        MetadataEnvelope $envelope
+    );
+
+    /**
+     * Dependency to provide an interface for building a decryption stream for
+     * cipher text given metadata and materials to do so.
+     *
+     * @param string $cipherText Plain-text data to be decrypted using the
+     *                           materials, algorithm, and data provided.
+     * @param MaterialsProvider $provider A provider to supply and encrypt
+     *                                    materials used in encryption.
+     * @param MetadataEnvelope $envelope A storage envelope for encryption
+     *                                   metadata to be read from.
+     * @param array $cipherOptions Additional verification options.
+     *
+     * @return AesStreamInterface
+     *
+     * @internal
+     */
+    abstract public function decrypt(
+        $cipherText,
+        MaterialsProvider $provider,
+        MetadataEnvelope $envelope,
+        array $cipherOptions = []
+    );
+}