Functions dealing with layered circuit encryption. This file aims to provide an API around the crypt_path_t structure which holds crypto information about a specific hop of a circuit. More...

#include "core/or/or.h"
#include "core/or/crypt_path.h"
#include "core/crypto/relay_crypto.h"
#include "core/crypto/onion_crypto.h"
#include "core/or/circuitbuild.h"
#include "core/or/circuitlist.h"
#include "core/or/extendinfo.h"
#include "core/or/congestion_control_common.h"
#include "lib/crypt_ops/crypto_dh.h"
#include "lib/crypt_ops/crypto_util.h"
#include "core/or/crypt_path_st.h"
#include "core/or/cell_st.h"

Functions
void	cpath_extend_linked_list (crypt_path_t *head_ptr, crypt_path_t new_hop)

int	cpath_append_hop (crypt_path_t *head_ptr, extend_info_t choice)

void	cpath_assert_ok (const crypt_path_t *cp)

void	cpath_assert_layer_ok (const crypt_path_t *cp)

int	cpath_init_circuit_crypto (relay_crypto_alg_t alg, crypt_path_t cpath, const char key_data, size_t key_data_len)

void	cpath_free (crypt_path_t *victim)

const uint8_t *	cpath_get_sendme_tag (crypt_path_t cpath, size_t len_out)

crypt_path_t *	cpath_get_next_non_open_hop (crypt_path_t *cpath)

Detailed Description

Functions dealing with layered circuit encryption. This file aims to provide an API around the crypt_path_t structure which holds crypto information about a specific hop of a circuit.

TODO: We should eventually move all functions dealing and manipulating crypt_path_t to this file, so that eventually we encapsulate more and more of crypt_path_t. Here are some more functions that can be moved here with some more effort:

circuit_list_path_impl()

Definition in file crypt_path.c.

Macro Definition Documentation

◆ CRYPT_PATH_PRIVATE

#define CRYPT_PATH_PRIVATE

Definition at line 20 of file crypt_path.c.

Function Documentation

◆ cpath_append_hop()

int cpath_append_hop	(	crypt_path_t **	head_ptr,
		extend_info_t *	choice
	)

Create a new hop, annotate it with information about its corresponding router choice, and append it to the end of the cpath head_ptr.

Definition at line 59 of file crypt_path.c.

Referenced by circuit_append_new_exit(), and onion_extend_cpath().

◆ cpath_assert_layer_ok()

void cpath_assert_layer_ok ( const crypt_path_t * cp )

Verify that cpath layer cp has all of its invariants correct. Trigger an assert if anything is invalid.

Definition at line 107 of file crypt_path.c.

Referenced by assert_connection_ok(), and cpath_assert_ok().

◆ cpath_assert_ok()

void cpath_assert_ok ( const crypt_path_t * cp )

Verify that cpath cp has all of its invariants correct. Trigger an assert if anything is invalid.

Definition at line 84 of file crypt_path.c.

Referenced by assert_circuit_ok().

◆ cpath_extend_linked_list()

void cpath_extend_linked_list	(	crypt_path_t **	head_ptr,
		crypt_path_t *	new_hop
	)

Add new_hop to the end of the doubly-linked-list head_ptr. This function is used to extend cpath by another hop.

Definition at line 42 of file crypt_path.c.

Referenced by cpath_append_hop(), and finalize_rend_circuit().

◆ cpath_free()

void cpath_free ( crypt_path_t * victim )

Deallocate space associated with the cpath node victim.

Definition at line 159 of file crypt_path.c.

Referenced by circuit_clear_cpath(), and circuit_truncated().

◆ cpath_get_next_non_open_hop()

crypt_path_t * cpath_get_next_non_open_hop ( crypt_path_t * cpath )

Return the first non-open hop in cpath, or return NULL if all hops are open.

Definition at line 188 of file crypt_path.c.

Referenced by circuit_finish_handshake(), circuit_handle_first_hop(), and circuit_send_next_onion_skin().

◆ cpath_get_sendme_tag()

const uint8_t * cpath_get_sendme_tag	(	crypt_path_t *	cpath,
		size_t *	len_out
	)

Return the sendme tag of this cpath, along with its length.

Definition at line 178 of file crypt_path.c.

Referenced by sendme_circuit_consider_sending().

◆ cpath_init_circuit_crypto()

int cpath_init_circuit_crypto	(	relay_crypto_alg_t	alg,
		crypt_path_t *	cpath,
		const char *	key_data,
		size_t	key_data_len
	)

Initialize cpath->{f|b}_{crypto|digest} from the key material in key_data.

If is_hs_v3 is set, this cpath will be used for next gen hidden service circuits and key_data must be at least HS_NTOR_KEY_EXPANSION_KDF_OUT_LEN bytes in length.

If is_hs_v3 is not set, key_data must contain CPATH_KEY_MATERIAL_LEN bytes, which are used as follows:

20 to initialize f_digest
20 to initialize b_digest
16 to key f_crypto
16 to key b_crypto

(If 'reverse' is true, then f_XX and b_XX are swapped.)

Return 0 if init was successful, else -1 if it failed.

Definition at line 148 of file crypt_path.c.

Referenced by circuit_finish_handshake(), and create_rend_cpath().