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 "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 (crypt_path_t cpath, const char key_data, size_t key_data_len, int reverse, int is_hs_v3)

void	cpath_free (crypt_path_t *victim)

void	cpath_crypt_cell (const crypt_path_t cpath, uint8_t payload, bool is_decrypt)

struct crypto_digest_t *	cpath_get_incoming_digest (const crypt_path_t *cpath)

void	cpath_set_cell_forward_digest (crypt_path_t cpath, cell_t cell)

uint8_t *	cpath_get_sendme_digest (crypt_path_t *cpath)

void	cpath_sendme_record_cell_digest (crypt_path_t *cpath, bool is_foward_digest)

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.

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 58 of file crypt_path.c.

◆ 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 103 of file crypt_path.c.

Referenced by 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 80 of file crypt_path.c.

◆ cpath_crypt_cell()

void cpath_crypt_cell	(	const crypt_path_t *	cpath,
		uint8_t *	payload,
		bool	is_decrypt
	)

Encrypt or decrypt payload using the crypto of cpath. Actual operation decided by is_decrypt.

Definition at line 178 of file crypt_path.c.

◆ 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 41 of file crypt_path.c.

◆ 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().

◆ cpath_get_incoming_digest()

struct crypto_digest_t* cpath_get_incoming_digest ( const crypt_path_t * cpath )

Getter for the incoming digest of cpath.

Definition at line 189 of file crypt_path.c.

◆ 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 225 of file crypt_path.c.

Referenced by circuit_handle_first_hop().

◆ cpath_get_sendme_digest()

uint8_t* cpath_get_sendme_digest ( crypt_path_t * cpath )

Return the sendme_digest of this cpath.

Definition at line 206 of file crypt_path.c.

◆ cpath_init_circuit_crypto()

int cpath_init_circuit_crypto	(	crypt_path_t *	cpath,
		const char *	key_data,
		size_t	key_data_len,
		int	reverse,
		int	is_hs_v3
	)

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 147 of file crypt_path.c.

◆ cpath_sendme_record_cell_digest()

void cpath_sendme_record_cell_digest	(	crypt_path_t *	cpath,
		bool	is_foward_digest
	)

Record the cell digest, indicated by is_foward_digest or not, as the SENDME cell digest.

Definition at line 214 of file crypt_path.c.

◆ cpath_set_cell_forward_digest()

void cpath_set_cell_forward_digest	(	crypt_path_t *	cpath,
		cell_t *	cell
	)

Set the right integrity digest on the outgoing cell based on the cell payload and update the forward digest of cpath.

Definition at line 197 of file crypt_path.c.

Referenced by relay_encrypt_cell_outbound().