/*

* (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>

// Use pwdhash.h

BOTAN_FUTURE_INTERNAL_HEADER(bcrypt_pbkdf.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);

      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() = default;

      std::string name() const override;

      std::unique_ptr<PasswordHash> tune(size_t output_length,

                                         std::chrono::milliseconds msec,

                                         size_t max_memory,

                                         std::chrono::milliseconds tune_msec) 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

*/

BOTAN_DEPRECATED("Use PasswordHashFamily+PasswordHash")

inline void bcrypt_pbkdf(uint8_t output[],

                         size_t output_len,

                         const char* password,

                         size_t password_len,

                         const uint8_t salt[],

                         size_t salt_len,

                         size_t rounds) {

   auto pwdhash_fam = PasswordHashFamily::create_or_throw("Bcrypt-PBKDF");

   auto pwdhash = pwdhash_fam->from_params(rounds);

   pwdhash->derive_key(output, output_len, password, password_len, salt, salt_len);

}

}  // namespace Botan

#endif