<?php
	/**
	 * DES加密/解密，RSA加密/验签
	 */
	class Crypt{
		// DES加密
		public function encrypt($str,$key){  
			$block = mcrypt_get_block_size('des', 'ecb');  
			$pad = $block - (strlen($str) % $block);  
			$str .= str_repeat(chr($pad), $pad);  
			$str = mcrypt_encrypt(MCRYPT_DES, $key, $str, MCRYPT_MODE_ECB);  
			return base64_encode($str);  
		}  

		// DES解密
		public function decrypt($str,$key){ 
			$str = base64_decode($str);  
			$str = mcrypt_decrypt(MCRYPT_DES, $key, $str, MCRYPT_MODE_ECB);  
			$block = mcrypt_get_block_size('des', 'ecb');  
			$pad = ord($str[($len = strlen($str)) - 1]);  
			return substr($str, 0, strlen($str) - $pad);  
		}  

		// RSA签名(SHA1WithRSA算法)
		public function sign($content,$rsaPrivateKeyPem){
			$priKey = file_get_contents($rsaPrivateKeyPem);
			$res = openssl_get_privatekey($priKey);
			openssl_sign($content, $sign, $res);
			openssl_free_key($res);
			$sign = base64_encode($sign);
			return $sign;
		}

		// RSA验签
		public function verify($data,$sign,$publicRsaPath){
			//读取公钥文件
			$pubKey = file_get_contents($publicRsaPath);
			//转换为openssl格式密钥
			$res = openssl_get_publickey($pubKey);
			//调用openssl内置方法验签，返回bool值
			$result = (bool)openssl_verify($data, base64_decode($sign), $res);
			//释放资源
			openssl_free_key($res);
			//返回资源是否成功
			return $result;
		}
	}