<?php

/**
 * php blowfish 算法
 * Class blowfish
 */
class blowfish{
	/**
	 * blowfish + cbc模式 + pkcs5補(bǔ)碼  加密
	 * @param string $str 需要加密的數(shù)據(jù)
	 * @return string 加密后base64加密的數(shù)據(jù)
	 */
	public function blowfish_cbc_pkcs5_encrypt($str)
	{
		$cipher = mcrypt_module_open(MCRYPT_BLOWFISH, '', MCRYPT_MODE_CBC, '');

		//pkcs5補(bǔ)碼
		$size = mcrypt_get_block_size(MCRYPT_BLOWFISH, MCRYPT_MODE_CBC);
		$str = $this->pkcs5_pad($str, $size);

		if (mcrypt_generic_init($cipher, $this->key, $this->iv) != -1)
        {
           $cipherText = mcrypt_generic($cipher, $str);
           mcrypt_generic_deinit($cipher);

           return base64_encode($cipherText);
        }

        mcrypt_module_close($cipher);
	}

	/**
	 * blowfish + cbc模式 + pkcs5  解密 去補(bǔ)碼
	 * @param string $str 加密的數(shù)據(jù)
	 * @return string 解密的數(shù)據(jù)
	 */
	public function blowfish_cbc_pkcs5_decrypt($str)
	{
		$cipher = mcrypt_module_open(MCRYPT_BLOWFISH, '', MCRYPT_MODE_CBC, '');

		if (mcrypt_generic_init($cipher, $this->key, $this->iv) != -1)
        {
           $cipherText = mdecrypt_generic($cipher, base64_decode($str));
           mcrypt_generic_deinit($cipher);

           return $this->pkcs5_unpad($cipherText);
        }

		mcrypt_module_close($cipher);
	}

	private function pkcs5_pad($text, $blocksize){
		$pad = $blocksize - (strlen ( $text ) % $blocksize);
		return $text . str_repeat ( chr ( $pad ), $pad );
	}

	private function pkcs5_unpad($str){
		$pad = ord($str[($len = strlen($str)) - 1]);
		return substr($str, 0, strlen($str) - $pad);
	}
}