tls_version.cpp

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/*
* TLS Protocol Version Management
* (C) 2012 Jack Lloyd
*     2021 Elektrobit Automotive GmbH
*     2022 René Meusel, Hannes Rantzsch - neXenio GmbH
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
 
#include <botan/tls_version.h>
#include <botan/tls_exceptn.h>
 
namespace Botan::TLS {
 
std::string Protocol_Version::to_string() const
   {
   const uint8_t maj = major_version();
   const uint8_t min = minor_version();
 
   if(maj == 3 && min == 0)
      return "SSL v3";
 
   if(maj == 3 && min >= 1) // TLS v1.x
      return "TLS v1." + std::to_string(min-1);
 
   if(maj == 254) // DTLS 1.x
      return "DTLS v1." + std::to_string(255 - min);
 
   // Some very new or very old protocol (or bogus data)
   return "Unknown " + std::to_string(maj) + "." + std::to_string(min);
   }
 
bool Protocol_Version::is_datagram_protocol() const
   {
   return major_version() > 250;
   }
 
bool Protocol_Version::is_pre_tls_13() const
   {
   return (!is_datagram_protocol() && *this <= Protocol_Version::TLS_V12) ||
          ( is_datagram_protocol() && *this <= Protocol_Version::DTLS_V12);
   }
 
bool Protocol_Version::is_tls_13_or_later() const
   {
   return (!is_datagram_protocol() && *this >= Protocol_Version::TLS_V13) ||
          ( is_datagram_protocol() && *this >= Protocol_Version::DTLS_V13);
   }
 
 
bool Protocol_Version::operator>(const Protocol_Version& other) const
   {
   if(this->is_datagram_protocol() != other.is_datagram_protocol())
      throw TLS_Exception(Alert::ProtocolVersion,
                          "Version comparing " + to_string() +
                          " with " + other.to_string());
 
   if(this->is_datagram_protocol())
      return m_version < other.m_version; // goes backwards
 
   return m_version > other.m_version;
   }
 
bool Protocol_Version::valid() const
   {
   const uint8_t maj = major_version();
   const uint8_t min = minor_version();
 
   if(maj == 3 && min <= 4)
     // 3.0: SSLv3
     // 3.1: TLS 1.0
     // 3.2: TLS 1.1
     // 3.3: TLS 1.2
     // 3.4: TLS 1.3
     return true;
 
   if(maj == 254 && (min == 253 || min == 255))
      // 254.253: DTLS 1.2
      // 254.255: DTLS 1.0
      return true;
 
   return false;
   }
 
bool Protocol_Version::known_version() const
   {
   return (m_version == static_cast<uint16_t>(Protocol_Version::TLS_V12) ||
#if defined(BOTAN_HAS_TLS_13)
           m_version == static_cast<uint16_t>(Protocol_Version::TLS_V13) ||
#endif
           m_version == static_cast<uint16_t>(Protocol_Version::DTLS_V12));
   }
 
}