由于mcrypt是一种废弃软件，不再建议使用，因此这里是使用openssl的示例。
class AES256Encryption{ public const BLOCK_SIZE = 8; public const IV_LENGTH = 16; public const CIPHER = 'AES256'; public static function generateIv(bool $allowLessSecure = false): string { $success = false; $random = openssl_random_pseudo_bytes(openssl_cipher_iv_length(static::CIPHER)); if (!$success) { if (function_exists('sodium_randombytes_random16')) { $random = sodium_randombytes_random16(); } else { try { $random = random_bytes(static::IV_LENGTH); } catch (Exception $e) { if ($allowLessSecure) { $permitted_chars = implode( '', array_merge( range('A', 'z'), range(0, 9), str_split('~!@#$%&*()-=+{};:"<>,.?/'') ) ); $random = ''; for ($i = 0; $i < static::IV_LENGTH; $i++) { $random .= $permitted_chars[mt_rand(0, (static::IV_LENGTH) - 1)]; } } else { throw new RuntimeException('Unable to generate initialization vector (IV)'); } } } } return $random; } protected static function getPaddedText(string $plainText): string { $stringLength = strlen($plainText); if ($stringLength % static::BLOCK_SIZE) { $plainText = str_pad($plainText, $stringLength + static::BLOCK_SIZE - $stringLength % static::BLOCK_SIZE, " "); } return $plainText; } public static function encrypt(string $plainText, string $key, string $iv): string { $plainText = static::getPaddedText($plainText); return base64_enpre(openssl_encrypt($plainText, static::CIPHER, $key, OPENSSL_RAW_DATA, $iv)); } public static function decrypt(string $encryptedText, string $key, string $iv): string { return openssl_decrypt(base64_depre($encryptedText), static::CIPHER, $key, OPENSSL_RAW_DATA, $iv); }}$text = '8SViI0Gz4r-p7A15YxkwjOBFuW*@NTtbm{U]D&E=~6yLM+adX'P;h3$,KJ%/eo>}<Rs:2#gZ.9fqn"Cv_^[(Hc!)?`Ql';$key = 'secretkey';$iv = AES256Encryption::generateIv();$encryptedText = AES256Encryption::encrypt($text, $key, $iv);$decryptedText = AES256Encryption::decrypt($encryptedText, $key, $iv);printf('Original Text: %s%s', $text, PHP_EOL);printf('Encrypted: %s%s', $encryptedText, PHP_EOL);printf('Decrypted: %s%s', $decryptedText, PHP_EOL);输出：
// Long string with lots of different charactersOriginal Text: 8SViI0Gz4r-p7A15YxkwjOBFuW*@NTtbm{U]D&E=~6yLM+adX'P;h3$,KJ%/eo>}<Rs:2#gZ.9fqn"Cv_^[(Hc!)?`QlEncrypted : rsiF4PMCMyvAp+CTuJrxJYGoV4BSy8Fy+q+FL8m64+Mt5V3o0HS0elRkWXsy+//hPjzNhjmVktxVvMY55Negt4DyLcf2QpH05wUX+adJDe634J/9fWd+nlEFoDutXuhY+/Kep9zUZFDmLmszJaBHWQ==Decrypted : 8SViI0Gz4r-p7A15YxkwjOBFuW*@NTtbm{U]D&E=~6yLM+adX'P;h3$,KJ%/eo>}<Rs:2#gZ.9fqn"Cv_^[(Hc!)?`Ql旧答案
尝试使用此PHP5类使用mcrypt进行加密。在这种情况下，它使用的是AES加密。您需要为使用它的每个站点更改密钥。如果您至少不使用它，它可能会指导您编写自己的版本。
<?phpclass Encryption{ const CIPHER = MCRYPT_RIJNDAEL_128; // Rijndael-128 is AES const MODE = MCRYPT_MODE_CBC; private $key; public function __construct($key) { $this->key = $key; } public function encrypt($plaintext) { $ivSize = mcrypt_get_iv_size(self::CIPHER, self::MODE); $iv = mcrypt_create_iv($ivSize, MCRYPT_DEV_URANDOM); $ciphertext = mcrypt_encrypt(self::CIPHER, $this->key, $plaintext, self::MODE, $iv); return base64_enpre($iv.$ciphertext); } public function decrypt($ciphertext) { $ciphertext = base64_depre($ciphertext); $ivSize = mcrypt_get_iv_size(self::CIPHER, self::MODE); if (strlen($ciphertext) < $ivSize) { throw new Exception('Missing initialization vector'); } $iv = substr($ciphertext, 0, $ivSize); $ciphertext = substr($ciphertext, $ivSize); $plaintext = mcrypt_decrypt(self::CIPHER, $this->key, $ciphertext, self::MODE, $iv); return rtrim($plaintext, " "); }}用法：
$key = ;$crypt = new Encryption($key);$encrypted_string = $crypt->encrypt('this is a test');$decrypted_string = $crypt->decrypt($encrypted_string); // this is a test笔记：
- 此类不适用于二进制数据（可能以NUL字节结尾）
- 此类不提供经过身份验证的加密。
