src/core/crypto/onion_ntor.h

   1 /* Copyright (c) 2012-2021, The Tor Project, Inc. */
   2 /* See LICENSE for licensing information */
   3
   4 /**
   5  * @file onion_ntor.h
   6  * @brief Header for onion_ntor.c
   7  **/
   8
   9 #ifndef TOR_ONION_NTOR_H
  10 #define TOR_ONION_NTOR_H
  11
  12 #include "lib/cc/torint.h"
  13
  14 struct di_digest256_map_t;
  15 struct curve25519_public_key_t;
  16 struct curve25519_keypair_t;
  17
  18 /** State to be maintained by a client between sending an ntor onionskin
  19  * and receiving a reply. */
  20 typedef struct ntor_handshake_state_t ntor_handshake_state_t;
  21
  22 /** Length of an ntor onionskin, as sent from the client to server. */
  23 #define NTOR_ONIONSKIN_LEN 84
  24 /** Length of an ntor reply, as sent from server to client. */
  25 #define NTOR_REPLY_LEN 64
  26
  27 void ntor_handshake_state_free_(ntor_handshake_state_t *state);
  28 #define ntor_handshake_state_free(state) \
  29   FREE_AND_NULL(ntor_handshake_state_t, ntor_handshake_state_free_, (state))
  30
  31 int onion_skin_ntor_create(const uint8_t *router_id,
  32                            const struct curve25519_public_key_t *router_key,
  33                            ntor_handshake_state_t **handshake_state_out,
  34                            uint8_t *onion_skin_out);
  35
  36 int onion_skin_ntor_server_handshake(const uint8_t *onion_skin,
  37                            const struct di_digest256_map_t *private_keys,
  38                            const struct curve25519_keypair_t *junk_keypair,
  39                            const uint8_t *my_node_id,
  40                            uint8_t *handshake_reply_out,
  41                            uint8_t *key_out,
  42                            size_t key_out_len);
  43
  44 int onion_skin_ntor_client_handshake(
  45                              const ntor_handshake_state_t *handshake_state,
  46                              const uint8_t *handshake_reply,
  47                              uint8_t *key_out,
  48                              size_t key_out_len,
  49                              const char **msg_out);
  50
  51 #ifdef ONION_NTOR_PRIVATE
  52 #include "lib/crypt_ops/crypto_curve25519.h"
  53
  54 /** Storage held by a client while waiting for an ntor reply from a server. */
  55 struct ntor_handshake_state_t {
  56   /** Identity digest of the router we're talking to. */
  57   uint8_t router_id[DIGEST_LEN];
  58   /** Onion key of the router we're talking to. */
  59   curve25519_public_key_t pubkey_B;
  60
  61   /**
  62    * Short-lived keypair for use with this handshake.
  63    * @{ */
  64   curve25519_secret_key_t seckey_x;
  65   curve25519_public_key_t pubkey_X;
  66   /** @} */
  67 };
  68 #endif /* defined(ONION_NTOR_PRIVATE) */
  69
  70 #endif /* !defined(TOR_ONION_NTOR_H) */