/*
* (C) 2018,2019 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/

#ifndef BOTAN_PBKDF_BCRYPT_H_
#define BOTAN_PBKDF_BCRYPT_H_

#include <botan/pwdhash.h>

namespace Botan {

/**
* Bcrypt-PBKDF key derivation function
*/
class BOTAN_PUBLIC_API(2,11) Bcrypt_PBKDF final : public PasswordHash
   {
   public:
      Bcrypt_PBKDF(size_t iterations) : m_iterations(iterations) {}

      Bcrypt_PBKDF(const Bcrypt_PBKDF& other) = default;
      Bcrypt_PBKDF& operator=(const Bcrypt_PBKDF&) = default;

      /**
      * Derive a new key under the current Bcrypt-PBKDF parameter set
      */
      void derive_key(uint8_t out[], size_t out_len,
                      const char* password, size_t password_len,
                      const uint8_t salt[], size_t salt_len) const override;

      std::string to_string() const override;

      size_t iterations() const override { return m_iterations; }

      size_t parallelism() const override { return 0; }

      size_t memory_param() const override { return 0; }

      size_t total_memory_usage() const override { return 4096; }

   private:
      size_t m_iterations;
   };

class BOTAN_PUBLIC_API(2,11) Bcrypt_PBKDF_Family final : public PasswordHashFamily
   {
   public:
      Bcrypt_PBKDF_Family() {}

      std::string name() const override;

      std::unique_ptr<PasswordHash> tune(size_t output_length,
                                         std::chrono::milliseconds msec,
                                         size_t max_memory) const override;

      std::unique_ptr<PasswordHash> default_params() const override;

      std::unique_ptr<PasswordHash> from_iterations(size_t iter) const override;

      std::unique_ptr<PasswordHash> from_params(
         size_t i, size_t, size_t) const override;
   };

/**
* Bcrypt PBKDF compatible with OpenBSD bcrypt_pbkdf
*/
void BOTAN_UNSTABLE_API bcrypt_pbkdf(uint8_t output[], size_t output_len,
                                     const char* pass, size_t pass_len,
                                     const uint8_t salt[], size_t salt_len,
                                     size_t rounds);

}

#endif