text: #ifndef crypto_kx_H
  #define crypto_kx_H
  
  #include <stddef.h>
  
  #include "export.h"
  
  #ifdef __cplusplus
  # ifdef __GNUC__
  #  pragma GCC diagnostic ignored "-Wlong-long"
  # endif
  extern "C" {
  #endif
  
  #define crypto_kx_PUBLICKEYBYTES 32
  SODIUM_EXPORT
  size_t crypto_kx_publickeybytes(void);
  
  #define crypto_kx_SECRETKEYBYTES 32
  SODIUM_EXPORT
  size_t crypto_kx_secretkeybytes(void);
  
  #define crypto_kx_SEEDBYTES 32
  SODIUM_EXPORT
  size_t crypto_kx_seedbytes(void);
  
  #define crypto_kx_SESSIONKEYBYTES 32
  SODIUM_EXPORT
  size_t crypto_kx_sessionkeybytes(void);
  
  #define crypto_kx_PRIMITIVE "x25519blake2b"
  SODIUM_EXPORT
  const char *crypto_kx_primitive(void);
  
  SODIUM_EXPORT
  int crypto_kx_seed_keypair(unsigned char pk[crypto_kx_PUBLICKEYBYTES],
                             unsigned char sk[crypto_kx_SECRETKEYBYTES],
                             const unsigned char seed[crypto_kx_SEEDBYTES]);
  
  SODIUM_EXPORT
  int crypto_kx_keypair(unsigned char pk[crypto_kx_PUBLICKEYBYTES],
                        unsigned char sk[crypto_kx_SECRETKEYBYTES]);
  
  SODIUM_EXPORT
  int crypto_kx_client_session_keys(unsigned char rx[crypto_kx_SESSIONKEYBYTES],
                                    unsigned char tx[crypto_kx_SESSIONKEYBYTES],
                                    const unsigned char client_pk[crypto_kx_PUBLICKEYBYTES],
                                    const unsigned char client_sk[crypto_kx_SECRETKEYBYTES],
                                    const unsigned char server_pk[crypto_kx_PUBLICKEYBYTES])
              __attribute__ ((warn_unused_result));
  
  SODIUM_EXPORT
  int crypto_kx_server_session_keys(unsigned char rx[crypto_kx_SESSIONKEYBYTES],
                                    unsigned char tx[crypto_kx_SESSIONKEYBYTES],
                                    const unsigned char server_pk[crypto_kx_PUBLICKEYBYTES],
                                    const unsigned char server_sk[crypto_kx_SECRETKEYBYTES],
                                    const unsigned char client_pk[crypto_kx_PUBLICKEYBYTES])
              __attribute__ ((warn_unused_result));
  
  #ifdef __cplusplus
  }
  #endif
  
  #endif
  