onion.h File Reference

Header file for onion.c. More...

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Data Structures
struct	server_onion_keys_t
struct	create_cell_t
struct	created_cell_t
struct	extend_cell_t
struct	extended_cell_t

Macros
#define	MAX_ONIONSKIN_CHALLENGE_LEN   255
#define	MAX_ONIONSKIN_REPLY_LEN   255
#define	server_onion_keys_free(keys)   FREE_AND_NULL(server_onion_keys_t, server_onion_keys_free_, (keys))

Typedefs
typedef struct server_onion_keys_t	server_onion_keys_t
typedef struct create_cell_t	create_cell_t
typedef struct created_cell_t	created_cell_t
typedef struct extend_cell_t	extend_cell_t
typedef struct extended_cell_t	extended_cell_t

Functions
int	onion_pending_add (or_circuit_t *circ, struct create_cell_t *onionskin)
or_circuit_t *	onion_next_task (struct create_cell_t **onionskin_out)
int	onion_num_pending (uint16_t handshake_type)
void	onion_pending_remove (or_circuit_t *circ)
void	clear_pending_onions (void)
server_onion_keys_t *	server_onion_keys_new (void)
void	server_onion_keys_free_ (server_onion_keys_t *keys)
void	onion_handshake_state_release (onion_handshake_state_t *state)
int	onion_skin_create (int type, const extend_info_t *node, onion_handshake_state_t *state_out, uint8_t *onion_skin_out)
int	onion_skin_server_handshake (int type, const uint8_t *onion_skin, size_t onionskin_len, const server_onion_keys_t *keys, uint8_t *reply_out, uint8_t *keys_out, size_t key_out_len, uint8_t *rend_nonce_out)
int	onion_skin_client_handshake (int type, const onion_handshake_state_t *handshake_state, const uint8_t *reply, size_t reply_len, uint8_t *keys_out, size_t key_out_len, uint8_t *rend_authenticator_out, const char **msg_out)
void	create_cell_init (create_cell_t *cell_out, uint8_t cell_type, uint16_t handshake_type, uint16_t handshake_len, const uint8_t *onionskin)
int	create_cell_parse (create_cell_t *cell_out, const cell_t *cell_in)
int	created_cell_parse (created_cell_t *cell_out, const cell_t *cell_in)
int	extend_cell_parse (extend_cell_t *cell_out, const uint8_t command, const uint8_t *payload_in, size_t payload_len)
int	extended_cell_parse (extended_cell_t *cell_out, const uint8_t command, const uint8_t *payload_in, size_t payload_len)
int	create_cell_format (cell_t *cell_out, const create_cell_t *cell_in)
int	create_cell_format_relayed (cell_t *cell_out, const create_cell_t *cell_in)
int	created_cell_format (cell_t *cell_out, const created_cell_t *cell_in)
int	extend_cell_format (uint8_t *command_out, uint16_t *len_out, uint8_t *payload_out, const extend_cell_t *cell_in)
int	extended_cell_format (uint8_t *command_out, uint16_t *len_out, uint8_t *payload_out, const extended_cell_t *cell_in)

Detailed Description

Header file for onion.c.

Typedef Documentation

create_cell_t

typedef struct create_cell_t create_cell_t

A parsed CREATE, CREATE_FAST, or CREATE2 cell.

created_cell_t

typedef struct created_cell_t created_cell_t

A parsed CREATED, CREATED_FAST, or CREATED2 cell.

extend_cell_t

typedef struct extend_cell_t extend_cell_t

A parsed RELAY_EXTEND or RELAY_EXTEND2 cell

extended_cell_t

typedef struct extended_cell_t extended_cell_t

A parsed RELAY_EXTEND or RELAY_EXTEND2 cell

Function Documentation

clear_pending_onions()

void clear_pending_onions

(

void

)

Remove all circuits from the pending list. Called from tor_free_all.

create_cell_init()

void create_cell_init	(	create_cell_t *	cell_out,
		uint8_t	cell_type,
		uint16_t	handshake_type,
		uint16_t	handshake_len,
		const uint8_t *	onionskin
	)

Write the various parameters into the create cell. Separate from create_cell_parse() to make unit testing easier.

create_cell_parse()

int create_cell_parse	(	create_cell_t *	cell_out,
		const cell_t *	cell_in
	)

Parse a CREATE, CREATE_FAST, or CREATE2 cell from cell_in into cell_out. Return 0 on success, -1 on failure. (We reject some syntactically valid CREATE2 cells that we can't generate or react to.)

created_cell_format()

int created_cell_format	(	cell_t *	cell_out,
		const created_cell_t *	cell_in
	)

Fill cell_out with a correctly formatted version of the CREATED{,_FAST,2} cell in cell_in. Return 0 on success, -1 on failure.

created_cell_parse()

int created_cell_parse	(	created_cell_t *	cell_out,
		const cell_t *	cell_in
	)

Parse a CREATED, CREATED_FAST, or CREATED2 cell from cell_in into cell_out. Return 0 on success, -1 on failure.

extend_cell_format()

int extend_cell_format	(	uint8_t *	command_out,
		uint16_t *	len_out,
		uint8_t *	payload_out,
		const extend_cell_t *	cell_in
	)

Format the EXTEND{,2} cell in cell_in, storing its relay payload in payload_out, the number of bytes used in *len_out, and the relay command in *command_out. The payload_out must have RELAY_PAYLOAD_SIZE bytes available. Return 0 on success, -1 on failure.

extend_cell_parse()

int extend_cell_parse	(	extend_cell_t *	cell_out,
		const uint8_t	command,
		const uint8_t *	payload,
		size_t	payload_length
	)

Parse an EXTEND or EXTEND2 cell (according to command) from the payload_length bytes of payload into cell_out. Return 0 on success, -1 on failure.

extended_cell_format()

int extended_cell_format	(	uint8_t *	command_out,
		uint16_t *	len_out,
		uint8_t *	payload_out,
		const extended_cell_t *	cell_in
	)

Format the EXTENDED{,2} cell in cell_in, storing its relay payload in payload_out, the number of bytes used in *len_out, and the relay command in *command_out. The payload_out must have RELAY_PAYLOAD_SIZE bytes available. Return 0 on success, -1 on failure.

extended_cell_parse()

int extended_cell_parse	(	extended_cell_t *	cell_out,
		const uint8_t	command,
		const uint8_t *	payload,
		size_t	payload_len
	)

Parse an EXTENDED or EXTENDED2 cell (according to command) from the payload_length bytes of payload into cell_out. Return 0 on success, -1 on failure.

onion_handshake_state_release()

void onion_handshake_state_release

(

onion_handshake_state_t *

state

)

Release whatever storage is held in state, depending on its type, and clear its pointer.

onion_next_task()

or_circuit_t* onion_next_task

(

create_cell_t **

onionskin_out

)

Remove the highest priority item from ol_list[] and return it, or return NULL if the lists are empty.

onion_num_pending()

int onion_num_pending

(

uint16_t

handshake_type

)

Return the number of handshake_type-style create requests pending.

onion_pending_add()

int onion_pending_add	(	or_circuit_t *	circ,
		create_cell_t *	onionskin
	)

Add circ to the end of ol_list and return 0, except if ol_list is too long, in which case do nothing and return -1.

onion_pending_remove()

void onion_pending_remove

(

or_circuit_t *

circ

)

Go through ol_list, find the onion_queue_t element which points to circ, remove and free that element. Leave circ itself alone.

onion_skin_client_handshake()

int onion_skin_client_handshake	(	int	type,
		const onion_handshake_state_t *	handshake_state,
		const uint8_t *	reply,
		size_t	reply_len,
		uint8_t *	keys_out,
		size_t	keys_out_len,
		uint8_t *	rend_authenticator_out,
		const char **	msg_out
	)

Perform the final (client-side) step of a circuit-creation handshake of type type, using our state in handshake_state and the server's response in reply. On success, generate keys_out_len bytes worth of key material in keys_out_len, set rend_authenticator_out to the "KH" field that can be used to establish introduction points at this hop, and return 0. On failure, return -1, and set *msg_out to an error message if this is worth complaining to the user about.

onion_skin_create()

int onion_skin_create	(	int	type,
		const extend_info_t *	node,
		onion_handshake_state_t *	state_out,
		uint8_t *	onion_skin_out
	)

Perform the first step of a circuit-creation handshake of type type (one of ONION_HANDSHAKE_TYPE_*): generate the initial "onion skin" in onion_skin_out, and store any state information in state_out. Return -1 on failure, and the length of the onionskin on acceptance.

onion_skin_server_handshake()

int onion_skin_server_handshake	(	int	type,
		const uint8_t *	onion_skin,
		size_t	onionskin_len,
		const server_onion_keys_t *	keys,
		uint8_t *	reply_out,
		uint8_t *	keys_out,
		size_t	keys_out_len,
		uint8_t *	rend_nonce_out
	)

Perform the second (server-side) step of a circuit-creation handshake of type type, responding to the client request in onion_skin using the keys in keys. On success, write our response into reply_out, generate keys_out_len bytes worth of key material in keys_out_len, a hidden service nonce to rend_nonce_out, and return the length of the reply. On failure, return -1.

server_onion_keys_free_()

void server_onion_keys_free_

(

server_onion_keys_t *

keys

)

Release all storage held in keys.

server_onion_keys_new()

server_onion_keys_t* server_onion_keys_new

(

void

)

Return a new server_onion_keys_t object with all of the keys and other info we might need to do onion handshakes. (We make a copy of our keys for each cpuworker to avoid race conditions with the main thread, and to avoid locking)