pdns/ednscookies.hh

   1 /*
   2  * This file is part of PowerDNS or dnsdist.
   3  * Copyright -- PowerDNS.COM B.V. and its contributors
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of version 2 of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * In addition, for the avoidance of any doubt, permission is granted to
  10  * link this program with OpenSSL and to (re)distribute the binaries
  11  * produced as the result of such linking.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  21  */
  22 #pragma once
  23 #include "namespaces.hh"
  24 #include "iputils.hh"
  25
  26 struct EDNSCookiesOpt
  27 {
  28   static const size_t EDNSCookieSecretSize = 32;
  29   static const size_t EDNSCookieOptSize = 24;
  30
  31   EDNSCookiesOpt(){};
  32   EDNSCookiesOpt(const std::string& option);
  33   EDNSCookiesOpt(const char* option, unsigned int len);
  34
  35   bool makeFromString(const std::string& option);
  36   bool makeFromString(const char* option, unsigned int len);
  37
  38   size_t size() const
  39   {
  40     return server.size() + client.size();
  41   }
  42
  43   bool isWellFormed() const
  44   {
  45     // RFC7873 section 5.2.2
  46     //    In summary, valid cookie lengths are 8 and 16 to 40 inclusive.
  47     return (
  48       client.size() == 8 && (server.size() == 0 || (server.size() >= 8 && server.size() <= 32)));
  49   }
  50
  51   bool isValid(const string& secret, const ComboAddress& source) const;
  52   bool makeServerCookie(const string& secret, const ComboAddress& source);
  53   string makeOptString() const;
  54   string getServer() const
  55   {
  56     return server;
  57   }
  58   string getClient() const
  59   {
  60     return client;
  61   }
  62
  63 private:
  64   bool shouldRefresh() const;
  65
  66   // the client cookie
  67   string client;
  68   // the server cookie
  69   string server;
  70
  71   void getEDNSCookiesOptFromString(const char* option, unsigned int len);
  72 };