/*

* PBKDF

* (C) 2012 Jack Lloyd

*

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

*/

#include <botan/pbkdf.h>

#include <botan/exceptn.h>

#include <botan/internal/scan_name.h>

#if defined(BOTAN_HAS_PBKDF2)

#include <botan/pbkdf2.h>

#endif

#if defined(BOTAN_HAS_PGP_S2K)

#include <botan/pgp_s2k.h>

#endif

namespace Botan {

std::unique_ptr<PBKDF> PBKDF::create(const std::string& algo_spec,

                                     const std::string& provider)

   {

   const SCAN_Name req(algo_spec);

#if defined(BOTAN_HAS_PBKDF2)

   if(req.algo_name() == "PBKDF2")

      {

      // TODO OpenSSL

      if(provider.empty() || provider == "base")

         {

         if(auto mac = MessageAuthenticationCode::create("HMAC(" + req.arg(0) + ")"))

            return std::unique_ptr<PBKDF>(new PKCS5_PBKDF2(mac.release()));

         if(auto mac = MessageAuthenticationCode::create(req.arg(0)))

            return std::unique_ptr<PBKDF>(new PKCS5_PBKDF2(mac.release()));

         }

      return nullptr;

      }

#endif

#if defined(BOTAN_HAS_PGP_S2K)

   if(req.algo_name() == "OpenPGP-S2K" && req.arg_count() == 1)

      {

      if(auto hash = HashFunction::create(req.arg(0)))

         return std::unique_ptr<PBKDF>(new OpenPGP_S2K(hash.release()));

      }

#endif

   BOTAN_UNUSED(req);

   BOTAN_UNUSED(provider);

   return nullptr;

   }

//static

std::unique_ptr<PBKDF>

PBKDF::create_or_throw(const std::string& algo,

                             const std::string& provider)

   {

   if(auto pbkdf = PBKDF::create(algo, provider))

      {

      return pbkdf;

      }

   throw Lookup_Error("PBKDF", algo, provider);

   }

std::vector<std::string> PBKDF::providers(const std::string& algo_spec)

   {

   return probe_providers_of<PBKDF>(algo_spec, { "base", "openssl" });

   }

void PBKDF::pbkdf_timed(uint8_t out[], size_t out_len,

                        const std::string& passphrase,

                        const uint8_t salt[], size_t salt_len,

                        std::chrono::milliseconds msec,

                        size_t& iterations) const

   {

   iterations = pbkdf(out, out_len, passphrase, salt, salt_len, 0, msec);

   }

void PBKDF::pbkdf_iterations(uint8_t out[], size_t out_len,

                             const std::string& passphrase,

                             const uint8_t salt[], size_t salt_len,

                             size_t iterations) const

   {

   if(iterations == 0)

      throw Invalid_Argument(name() + ": Invalid iteration count");

   const size_t iterations_run = pbkdf(out, out_len, passphrase,

                                       salt, salt_len, iterations,

                                       std::chrono::milliseconds(0));

   BOTAN_ASSERT_EQUAL(iterations, iterations_run, "Expected PBKDF iterations");

   }

secure_vector<uint8_t> PBKDF::pbkdf_iterations(size_t out_len,

                                            const std::string& passphrase,

                                            const uint8_t salt[], size_t salt_len,

                                            size_t iterations) const

   {

   secure_vector<uint8_t> out(out_len);

   pbkdf_iterations(out.data(), out_len, passphrase, salt, salt_len, iterations);

   return out;

   }

secure_vector<uint8_t> PBKDF::pbkdf_timed(size_t out_len,

                                       const std::string& passphrase,

                                       const uint8_t salt[], size_t salt_len,

                                       std::chrono::milliseconds msec,

                                       size_t& iterations) const

   {

   secure_vector<uint8_t> out(out_len);

   pbkdf_timed(out.data(), out_len, passphrase, salt, salt_len, msec, iterations);

   return out;

   }

}