Tor  0.4.8.0-alpha-dev
crypt_path_st.h
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1 /* Copyright (c) 2001 Matej Pfajfar.
2  * Copyright (c) 2001-2004, Roger Dingledine.
3  * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
4  * Copyright (c) 2007-2021, The Tor Project, Inc. */
5 /* See LICENSE for licensing information */
6 
7 /**
8  * @file crypt_path_st.h
9  * @brief Path structures for origin circuits.
10  **/
11 
12 #ifndef CRYPT_PATH_ST_H
13 #define CRYPT_PATH_ST_H
14 
16 struct crypto_dh_t;
17 
18 #define CRYPT_PATH_MAGIC 0x70127012u
19 
22 struct crypto_dh_t;
24  /** One of `ONION_HANDSHAKE_TYPE_*`. Determines which member of the union
25  * is accessible. */
26  uint16_t tag;
27  union {
28  struct fast_handshake_state_t *fast;
29  struct crypto_dh_t *tap;
30  struct ntor_handshake_state_t *ntor;
31  struct ntor3_handshake_state_t *ntor3;
32  } u;
33 };
34 
36 
37 /** Macro to encapsulate private members of a struct.
38  *
39  * Renames 'x' to 'x_crypt_path_private_field'.
40  */
41 #define CRYPT_PATH_PRIV_FIELD(x) x ## _crypt_path_private_field
42 
43 #ifdef CRYPT_PATH_PRIVATE
44 
45 /* Helper macro to access private members of a struct. */
46 #define pvt_crypto CRYPT_PATH_PRIV_FIELD(crypto)
47 
48 #endif /* defined(CRYPT_PATH_PRIVATE) */
49 
50 /** Holds accounting information for a single step in the layered encryption
51  * performed by a circuit. Used only at the client edge of a circuit. */
52 struct crypt_path_t {
53  uint32_t magic;
54 
55  /** Current state of the handshake as performed with the OR at this
56  * step. */
58  /** Diffie-hellman handshake state for performing an introduction
59  * operations */
61 
62  /** Negotiated key material shared with the OR at this step. */
63  char rend_circ_nonce[DIGEST_LEN];/* KH in tor-spec.txt */
64 
65  /** Information to extend to the OR at this step. */
67 
68  /** Is the circuit built to this step? Must be one of:
69  * - CPATH_STATE_CLOSED (The circuit has not been extended to this step)
70  * - CPATH_STATE_AWAITING_KEYS (We have sent an EXTEND/CREATE to this step
71  * and not received an EXTENDED/CREATED)
72  * - CPATH_STATE_OPEN (The circuit has been extended to this step) */
73  uint8_t state;
74 #define CPATH_STATE_CLOSED 0
75 #define CPATH_STATE_AWAITING_KEYS 1
76 #define CPATH_STATE_OPEN 2
77  struct crypt_path_t *next; /**< Link to next crypt_path_t in the circuit.
78  * (The list is circular, so the last node
79  * links to the first.) */
80  struct crypt_path_t *prev; /**< Link to previous crypt_path_t in the
81  * circuit. */
82 
83  int package_window; /**< How many cells are we allowed to originate ending
84  * at this step? */
85  int deliver_window; /**< How many cells are we willing to deliver originating
86  * at this step? */
87 
88  /** Congestion control info */
90 
91  /*********************** Private members ****************************/
92 
93  /** Private member: Cryptographic state used for encrypting and
94  * authenticating relay cells to and from this hop. */
96 };
97 
98 #endif /* !defined(CRYPT_PATH_ST_H) */
#define DIGEST_LEN
Definition: digest_sizes.h:20
struct ntor_handshake_state_t ntor_handshake_state_t
Definition: onion_ntor.h:20
struct ntor3_handshake_state_t ntor3_handshake_state_t
Definition: onion_ntor_v3.h:25
Relay-cell encryption state structure.
struct crypt_path_t * prev
Definition: crypt_path_st.h:80
uint8_t state
Definition: crypt_path_st.h:73
relay_crypto_t CRYPT_PATH_PRIV_FIELD(crypto)
struct crypt_path_t * next
Definition: crypt_path_st.h:77
struct crypto_dh_t * rend_dh_handshake_state
Definition: crypt_path_st.h:60
extend_info_t * extend_info
Definition: crypt_path_st.h:66
char rend_circ_nonce[DIGEST_LEN]
Definition: crypt_path_st.h:63
onion_handshake_state_t handshake_state
Definition: crypt_path_st.h:57
struct congestion_control_t * ccontrol
Definition: crypt_path_st.h:89