/*

* DTLS Hello Verify Request

* (C) 2012 Jack Lloyd

*

* Botan is released under the Simplified BSD License (see license.txt)

*/

#include <botan/tls_messages.h>

#include <botan/mac.h>

namespace Botan::TLS {

Hello_Verify_Request::Hello_Verify_Request(const std::vector<uint8_t>& buf)

   {

   if(buf.size() < 3)

      throw Decoding_Error("Hello verify request too small");

   Protocol_Version version(buf[0], buf[1]);

   if(!version.is_datagram_protocol())

      {

      throw Decoding_Error("Unknown version from server in hello verify request");

      }

   if(static_cast<size_t>(buf[2]) + 3 != buf.size())

      throw Decoding_Error("Bad length in hello verify request");

   m_cookie.assign(buf.begin() + 3, buf.end());

   }

Hello_Verify_Request::Hello_Verify_Request(const std::vector<uint8_t>& client_hello_bits,

                                           const std::string& client_identity,

                                           const SymmetricKey& secret_key)

   {

   std::unique_ptr<MessageAuthenticationCode> hmac = MessageAuthenticationCode::create_or_throw("HMAC(SHA-256)");

   hmac->set_key(secret_key);

   hmac->update_be(static_cast<uint64_t>(client_hello_bits.size()));

   hmac->update(client_hello_bits);

   hmac->update_be(static_cast<uint64_t>(client_identity.size()));

   hmac->update(client_identity);

   m_cookie.resize(hmac->output_length());

   hmac->final(m_cookie.data());

   }

std::vector<uint8_t> Hello_Verify_Request::serialize() const

   {

   /* DTLS 1.2 server implementations SHOULD use DTLS version 1.0

      regardless of the version of TLS that is expected to be

      negotiated (RFC 6347, section 4.2.1)

   */

   Protocol_Version format_version(254, 255); // DTLS 1.0

   std::vector<uint8_t> bits;

   bits.push_back(format_version.major_version());

   bits.push_back(format_version.minor_version());

   bits.push_back(static_cast<uint8_t>(m_cookie.size()));

   bits += m_cookie;

   return bits;

   }

}