PHP中使用OpenSSL生成证书及加密解密

/*加密解密*/function authcode($string, $operation = 'E') {  $ssl_public = file_get_contents(DATA_PATH."/conf/cert_public.key");  $ssl_private = file_get_contents(DATA_PATH."/conf/cert_private.pem");  $pi_key = openssl_pkey_get_private($ssl_private);//这个函数可用来判断私钥是否是可用的，可用返回资源id Resource id  $pu_key = openssl_pkey_get_public($ssl_public);//这个函数可用来判断公钥是否是可用的  if(false == ($pi_key || $pu_key)) return '证书错误';  $data = "";  if($operation=='D'){    openssl_private_decrypt(base64_decode($string),$data,$pi_key);//私钥解密  }else{    openssl_public_encrypt($string,$data,$pu_key);//公钥加密    $data = base64_encode($data);  }  return $data;}/*生成证书*/function exportOpenSSLFile(){  $config = array(    "digest_alg"    => "sha512",    "private_key_bits" => 4096,           //字节数  512 1024 2048  4096 等    "private_key_type" => OPENSSL_KEYTYPE_RSA,   //加密类型  );  $res = openssl_pkey_new($config);  if($res == false) return false;  openssl_pkey_export($res, $private_key);  $public_key = openssl_pkey_get_details($res);  $public_key = $public_key["key"];  file_put_contents(DATA_PATH."/conf/cert_public.key",$public_key);  file_put_contents(DATA_PATH."/conf/cert_private.pem",$private_key);  openssl_free_key($res);}