/*

* TLS Cipher Suites

* (C) 2004-2011,2012 Jack Lloyd

*

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

*/

#ifndef BOTAN_TLS_CIPHER_SUITES_H_

#define BOTAN_TLS_CIPHER_SUITES_H_

#include <botan/types.h>

#include <botan/tls_algos.h>

#include <botan/tls_version.h>

#include <string>

#include <vector>

#include <optional>

namespace Botan {

namespace TLS {

/**

* Ciphersuite Information

*/

class BOTAN_PUBLIC_API(2,0) Ciphersuite final

   {

   public:

      /**

      * Convert an SSL/TLS ciphersuite to algorithm fields

      * @param suite the ciphersuite code number

      * @return ciphersuite object or std::nullopt if it is unknown to the library

      */

      static std::optional<Ciphersuite> by_id(uint16_t suite);

      /**

      * Convert an SSL/TLS ciphersuite name to algorithm fields

      * @param name the IANA name for the desired ciphersuite

      * @return ciphersuite object or std::nullopt if it is unknown to the library

      */

      static std::optional<Ciphersuite> from_name(const std::string& name);

      /**

      * Returns true iff this suite is a known SCSV

      */

      static bool is_scsv(uint16_t suite);

      /**

      * Generate a static list of all known ciphersuites and return it.

      *

      * @return list of all known ciphersuites

      */

      static const std::vector<Ciphersuite>& all_known_ciphersuites();

      /**

      * Formats the ciphersuite back to an RFC-style ciphersuite string

      * @return RFC ciphersuite string identifier

      */

      std::string to_string() const { return (!m_iana_id) ? "unknown cipher suite" : m_iana_id; }

      /**

      * @return ciphersuite number

      */

      uint16_t ciphersuite_code() const { return m_ciphersuite_code; }

      /**

      * @return true if this is a PSK ciphersuite

      */

      bool psk_ciphersuite() const;

      /**

      * @return true if this is an ECC ciphersuite

      */

      bool ecc_ciphersuite() const;

      /**

       * @return true if this suite uses a CBC cipher

       */

      bool cbc_ciphersuite() const;

      bool signature_used() const;

      /**

      * @return key exchange algorithm used by this ciphersuite

      */

      std::string kex_algo() const { return kex_method_to_string(kex_method()); }

      Kex_Algo kex_method() const { return m_kex_algo; }

      /**

      * @return signature algorithm used by this ciphersuite

      */

      std::string sig_algo() const { return auth_method_to_string(auth_method()); }

      Auth_Method auth_method() const { return m_auth_method; }

      /**

      * @return symmetric cipher algorithm used by this ciphersuite

      */

      std::string cipher_algo() const { return m_cipher_algo; }

      /**

      * @return message authentication algorithm used by this ciphersuite

      */

      std::string mac_algo() const { return m_mac_algo; }

      std::string prf_algo() const

         {

         return kdf_algo_to_string(m_prf_algo);

         }

      /**

      * @return cipher key length used by this ciphersuite

      */

      size_t cipher_keylen() const { return m_cipher_keylen; }

      size_t nonce_bytes_from_handshake() const;

      size_t nonce_bytes_from_record(Protocol_Version version) const;

      Nonce_Format nonce_format() const { return m_nonce_format; }

      size_t mac_keylen() const { return m_mac_keylen; }

      /**

      * @return true if this is a valid/known ciphersuite

      */

      bool valid() const { return m_usable; }

      bool usable_in_version(Protocol_Version version) const;

      bool operator<(const Ciphersuite& o) const { return ciphersuite_code() < o.ciphersuite_code(); }

      bool operator<(const uint16_t c) const { return ciphersuite_code() < c; }

   private:

      bool is_usable() const;

      Ciphersuite(uint16_t ciphersuite_code,

                  const char* iana_id,

                  Auth_Method auth_method,

                  Kex_Algo kex_algo,

                  const char* cipher_algo,

                  size_t cipher_keylen,

                  const char* mac_algo,

                  size_t mac_keylen,

                  KDF_Algo prf_algo,

                  Nonce_Format nonce_format) :

         m_ciphersuite_code(ciphersuite_code),

         m_iana_id(iana_id),

         m_auth_method(auth_method),

         m_kex_algo(kex_algo),

         m_prf_algo(prf_algo),

         m_nonce_format(nonce_format),

         m_cipher_algo(cipher_algo),

         m_mac_algo(mac_algo),

         m_cipher_keylen(cipher_keylen),

         m_mac_keylen(mac_keylen)

         {

         m_usable = is_usable();

         }

      uint16_t m_ciphersuite_code = 0;

      /*

      All of these const char* strings are references to compile time

      constants in tls_suite_info.cpp

      */

      const char* m_iana_id;

      Auth_Method m_auth_method;

      Kex_Algo m_kex_algo;

      KDF_Algo m_prf_algo;

      Nonce_Format m_nonce_format;

      const char* m_cipher_algo;

      const char* m_mac_algo;

      size_t m_cipher_keylen;

      size_t m_mac_keylen;

      bool m_usable = false;

   };

}

}

#endif