/*
* EME Base Class
* (C) 1999-2008 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/

#include <botan/internal/eme.h>
#include <botan/internal/scan_name.h>
#include <botan/exceptn.h>
#include <botan/internal/parsing.h>

#if defined(BOTAN_HAS_EME_OAEP)
#include <botan/internal/oaep.h>
#endif

#if defined(BOTAN_HAS_EME_PKCS1)
#include <botan/internal/eme_pkcs.h>
#endif

#if defined(BOTAN_HAS_EME_RAW)
#include <botan/internal/eme_raw.h>
#endif

namespace Botan {

std::unique_ptr<EME> EME::create(const std::string& algo_spec)
   {
#if defined(BOTAN_HAS_EME_RAW)
   if(algo_spec == "Raw")
      return std::make_unique<EME_Raw>();
#endif

#if defined(BOTAN_HAS_EME_PKCS1)
   if(algo_spec == "PKCS1v15" || algo_spec == "EME-PKCS1-v1_5")
      return std::make_unique<EME_PKCS1v15>();
#endif

#if defined(BOTAN_HAS_EME_OAEP)
   SCAN_Name req(algo_spec);

   if(req.algo_name() == "OAEP" ||
      req.algo_name() == "EME-OAEP" ||
      req.algo_name() == "EME1")
      {
      if(req.arg_count() == 1 ||
         ((req.arg_count() == 2 || req.arg_count() == 3) && req.arg(1) == "MGF1"))
         {
         if(auto hash = HashFunction::create(req.arg(0)))
            return std::make_unique<OAEP>(std::move(hash), req.arg(2, ""));
         }
      else if(req.arg_count() == 2 || req.arg_count() == 3)
         {
         auto mgf_params = parse_algorithm_name(req.arg(1));

         if(mgf_params.size() == 2 && mgf_params[0] == "MGF1")
            {
            auto hash = HashFunction::create(req.arg(0));
            auto mgf1_hash = HashFunction::create(mgf_params[1]);

            if(hash && mgf1_hash)
               {
               return std::make_unique<OAEP>(std::move(hash),
                                             std::move(mgf1_hash),
                                             req.arg(2, ""));
               }
            }
         }
      }
#endif

   throw Algorithm_Not_Found(algo_spec);
   }

/*
* Encode a message
*/
secure_vector<uint8_t> EME::encode(const uint8_t msg[], size_t msg_len,
                                size_t key_bits,
                                RandomNumberGenerator& rng) const
   {
   return pad(msg, msg_len, key_bits, rng);
   }

/*
* Encode a message
*/
secure_vector<uint8_t> EME::encode(const secure_vector<uint8_t>& msg,
                                size_t key_bits,
                                RandomNumberGenerator& rng) const
   {
   return pad(msg.data(), msg.size(), key_bits, rng);
   }


}