1 files changed, 67 insertions, 0 deletions
diff --git a/lib/facebook-graph-sdk/src/Facebook/PseudoRandomString/OpenSslPseudoRandomStringGenerator.php b/lib/facebook-graph-sdk/src/Facebook/PseudoRandomString/OpenSslPseudoRandomStringGenerator.php
new file mode 100644
index 0000000..f4ea6b8
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+++ b/lib/facebook-graph-sdk/src/Facebook/PseudoRandomString/OpenSslPseudoRandomStringGenerator.php
@@ -0,0 +1,67 @@
+<?php
+/**
+ * Copyright 2014 Facebook, Inc.
+ *
+ * You are hereby granted a non-exclusive, worldwide, royalty-free license to
+ * use, copy, modify, and distribute this software in source code or binary
+ * form for use in connection with the web services and APIs provided by
+ * Facebook.
+ *
+ * As with any software that integrates with the Facebook platform, your use
+ * of this software is subject to the Facebook Developer Principles and
+ * Policies [http://developers.facebook.com/policy/]. This copyright notice
+ * shall be included in all copies or substantial portions of the software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ */
+namespace Facebook\PseudoRandomString;
+
+use Facebook\Exceptions\FacebookSDKException;
+
+class OpenSslPseudoRandomStringGenerator implements PseudoRandomStringGeneratorInterface
+{
+    use PseudoRandomStringGeneratorTrait;
+
+    /**
+     * @const string The error message when generating the string fails.
+     */
+    const ERROR_MESSAGE = 'Unable to generate a cryptographically secure pseudo-random string from openssl_random_pseudo_bytes().';
+
+    /**
+     * @throws FacebookSDKException
+     */
+    public function __construct()
+    {
+        if (!function_exists('openssl_random_pseudo_bytes')) {
+            throw new FacebookSDKException(static::ERROR_MESSAGE . 'The function openssl_random_pseudo_bytes() does not exist.');
+        }
+    }
+
+    /**
+     * @inheritdoc
+     */
+    public function getPseudoRandomString($length)
+    {
+        $this->validateLength($length);
+
+        $wasCryptographicallyStrong = false;
+        $binaryString = openssl_random_pseudo_bytes($length, $wasCryptographicallyStrong);
+
+        if ($binaryString === false) {
+            throw new FacebookSDKException(static::ERROR_MESSAGE . 'openssl_random_pseudo_bytes() returned an unknown error.');
+        }
+
+        if ($wasCryptographicallyStrong !== true) {
+            throw new FacebookSDKException(static::ERROR_MESSAGE . 'openssl_random_pseudo_bytes() returned a pseudo-random string but it was not cryptographically secure and cannot be used.');
+        }
+
+        return $this->binToHex($binaryString, $length);
+    }
+}