1 files changed, 191 insertions, 0 deletions
diff --git a/bootstrap/comments/backend/classes/encryption.php b/bootstrap/comments/backend/classes/encryption.php
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+++ b/bootstrap/comments/backend/classes/encryption.php
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+<?php namespace HashOver;
+
+// Copyright (C) 2010-2018 Jacob Barkdull
+// This file is part of HashOver.
+//
+// HashOver 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.
+//
+// HashOver 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 HashOver.  If not, see <http://www.gnu.org/licenses/>.
+
+
+// Encryption methods
+class Encryption
+{
+	protected $prefix;
+	protected $cost = '$10$';
+	protected $encryptionHash;
+	protected $ivSize;
+	protected $cipher = 'aes-128-cbc';
+	protected $options;
+	protected $alphabet = 'aAbBcCdDeEfFgGhHiIjJkKlLmM.nNoOpPqQrRsStTuUvVwWxXyYzZ/0123456789';
+
+	public function __construct ($encryption_key)
+	{
+		// Throw exception if encryption key isn't at least 8 characters long
+		if (mb_strlen ($encryption_key, '8bit') < 8) {
+			throw new Exception ('Encryption key must by at least 8 characters long.');
+		}
+
+		// Blowfish prefix
+		$this->prefix = (version_compare (PHP_VERSION, '5.3.7') < 0) ? '$2a' : '$2y';
+
+		// OpenSSL raw output/options
+		$this->options = defined ('OPENSSL_RAW_DATA') ? OPENSSL_RAW_DATA : true;
+
+		// SHA-256 hash array
+		$this->encryptionHash = str_split (hash ('sha256', $encryption_key));
+
+		// OpenSSL cipher IV
+		$this->ivSize = openssl_cipher_iv_length ($this->cipher);
+	}
+
+	// Creates Blowfish hash for passwords
+	public function createHash ($string)
+	{
+		// Alphanumeric character array
+		$alphabet = str_split ($this->alphabet);
+
+		// Shuffle alphanumeric character array as to randomize it
+		shuffle ($alphabet);
+
+		// Initial salt
+		$salt = '';
+
+		// Generate random 20 character alphanumeric string
+		foreach (array_rand ($alphabet, 20) as $character) {
+			$salt .= $alphabet[$character];
+		}
+
+		// Blowfish hash
+		$hash = crypt ($string, $this->prefix . $this->cost . $salt . '$$');
+
+		// Return hashed string
+		return $hash;
+	}
+
+	// Creates Blowfish hash with salt from supplied hash
+	public function verifyHash ($string, $compare)
+	{
+		// Split string by dollar sign
+		$parts = explode ('$', $compare);
+
+		// Hash salt
+		$salt = !empty ($parts[3]) ? $parts[3] : '';
+
+		// Encryption string as Blowfish hash
+		$hash = crypt ($string, $this->prefix . $this->cost . $salt . '$$');
+
+		// Returns true if both match
+		return ($hash === $compare);
+	}
+
+	// Generates a random encryption key
+	public function createKey ($string)
+	{
+		// Shuffle alphanumeric character array as to randomize it
+		shuffle ($string);
+
+		// Initial array keys
+		$keys = array ();
+
+		// Initial key
+		$key = '';
+
+		// Generate random string from encryption key SHA-256 hash
+		for ($k = 0; $k < 16; $k++) {
+			// Add encryption key character index to keys array
+			$keys[] = array_search ($string[$k], $this->encryptionHash);
+
+			// Add encryption key character to key
+			$key .= $string[$k];
+		}
+
+		// Return random string and list of encryption hash array keys
+		return array (
+			'key' => $key,
+			'keys' => join (',', $keys)
+		);
+	}
+
+	// OpenSSL encrypt with random key from SHA-256 hash for e-mails
+	public function encrypt ($string)
+	{
+		// Get a random encryption key
+		$key_pair = $this->createKey ($this->encryptionHash);
+
+		// Get pseudo-random bytes for OpenSSL IV
+		$iv = openssl_random_pseudo_bytes ($this->ivSize);
+
+		// OpenSSL encrypt using random encryption key
+		$ciphertext = openssl_encrypt (
+			$string,
+			$this->cipher,
+			$key_pair['key'],
+			$this->options,
+			$iv
+		);
+
+		// Return encrypted value and list of encryption hash array keys
+		return array (
+			'encrypted' => base64_encode ($iv . $ciphertext),
+			'keys' => $key_pair['keys']
+		);
+	}
+
+	// Decrypt OpenSSL encrypted string
+	public function decrypt ($string, $keys)
+	{
+		// Return false if string or keys is empty
+		if (empty ($string) or empty ($keys)) {
+			return false;
+		}
+
+		// Initial key
+		$key = '';
+
+		// Split keys string into array
+		$keys = explode (',', $keys);
+
+		// Retrieve random key from array
+		foreach ($keys as $value) {
+			// Cast key to integer
+			$hash_key = (int)($value);
+
+			// Give up if any array value isn't valid
+			if (!isset ($this->encryptionHash[$hash_key])) {
+				return '';
+			}
+
+			// Add character to decryption key
+			$key .= $this->encryptionHash[$hash_key];
+		}
+
+		// Decode base64 encoded string
+		$decode = base64_decode ($string, true);
+
+		// Setup OpenSSL IV
+		$iv = mb_substr ($decode, 0, $this->ivSize, '8bit');
+
+		// Setup OpenSSL cipher text
+		$full_length = mb_strlen ($decode, '8bit');
+		$deciphertext = mb_substr ($decode, $this->ivSize, $full_length, '8bit');
+
+		// Return OpenSSL decrypted string
+		return openssl_decrypt (
+			$deciphertext,
+			$this->cipher,
+			$key,
+			$this->options,
+			$iv
+		);
+	}
+}