Extract the crypto parts of circuit_package_relay_cell.

This commit is contained in:
Nick Mathewson 2018-03-17 10:14:35 -04:00
parent 2989326054
commit 320dcf65b7
3 changed files with 47 additions and 21 deletions

View File

@ -487,6 +487,42 @@ relay_decrypt_cell(circuit_t *circ, cell_t *cell,
return 0;
}
/**
* Encrypt a cell <b>cell</b> that we are creating, and sending outbound on
* <b>circ</b> until the hop corresponding to <b>layer_hint</b>.
*/
void
relay_encrypt_cell_outbound(cell_t *cell,
origin_circuit_t *circ,
crypt_path_t *layer_hint)
{
crypt_path_t *thishop; /* counter for repeated crypts */
relay_set_digest(layer_hint->f_digest, cell);
thishop = layer_hint;
/* moving from farthest to nearest hop */
do {
tor_assert(thishop);
log_debug(LD_OR,"encrypting a layer of the relay cell.");
relay_crypt_one_payload(thishop->f_crypto, cell->payload);
thishop = thishop->prev;
} while (thishop != circ->cpath->prev);
}
/**
* Encrypt a cell <b>cell</b> that we are creating, and sending on
* <b>circuit</b> to the origin.
*/
void
relay_encrypt_cell_inbound(cell_t *cell,
or_circuit_t *or_circ)
{
relay_set_digest(or_circ->p_digest, cell);
/* encrypt one layer */
relay_crypt_one_payload(or_circ->p_crypto, cell->payload);
}
/** Package a relay cell from an edge:
* - Encrypt it to the right layer
* - Append it to the appropriate cell_queue on <b>circ</b>.
@ -505,7 +541,6 @@ circuit_package_relay_cell(cell_t *cell, circuit_t *circ,
}
if (cell_direction == CELL_DIRECTION_OUT) {
crypt_path_t *thishop; /* counter for repeated crypts */
chan = circ->n_chan;
if (!chan) {
log_warn(LD_BUG,"outgoing relay cell sent from %s:%d has n_chan==NULL."
@ -528,20 +563,8 @@ circuit_package_relay_cell(cell_t *cell, circuit_t *circ,
return 0; /* just drop it */
}
relay_set_digest(layer_hint->f_digest, cell);
thishop = layer_hint;
/* moving from farthest to nearest hop */
do {
tor_assert(thishop);
log_debug(LD_OR,"encrypting a layer of the relay cell.");
relay_crypt_one_payload(thishop->f_crypto, cell->payload);
thishop = thishop->prev;
} while (thishop != TO_ORIGIN_CIRCUIT(circ)->cpath->prev);
relay_encrypt_cell_outbound(cell, TO_ORIGIN_CIRCUIT(circ), layer_hint);
} else { /* incoming cell */
or_circuit_t *or_circ;
if (CIRCUIT_IS_ORIGIN(circ)) {
/* We should never package an _incoming_ cell from the circuit
* origin; that means we messed up somewhere. */
@ -549,11 +572,9 @@ circuit_package_relay_cell(cell_t *cell, circuit_t *circ,
assert_circuit_ok(circ);
return 0; /* just drop it */
}
or_circ = TO_OR_CIRCUIT(circ);
or_circuit_t *or_circ = TO_OR_CIRCUIT(circ);
relay_encrypt_cell_inbound(cell, or_circ);
chan = or_circ->p_chan;
relay_set_digest(or_circ->p_digest, cell);
/* encrypt one layer */
relay_crypt_one_payload(or_circ->p_crypto, cell->payload);
}
++stats_n_relay_cells_relayed;

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@ -90,8 +90,12 @@ void circuit_clear_cell_queue(circuit_t *circ, channel_t *chan);
void stream_choice_seed_weak_rng(void);
int relay_crypt(circuit_t *circ, cell_t *cell, cell_direction_t cell_direction,
int relay_decrypt_cell(circuit_t *circ, cell_t *cell,
cell_direction_t cell_direction,
crypt_path_t **layer_hint, char *recognized);
void relay_encrypt_cell_outbound(cell_t *cell, origin_circuit_t *or_circ,
crypt_path_t *layer_hint);
void relay_encrypt_cell_inbound(cell_t *cell, or_circuit_t *or_circ);
circid_t packed_cell_get_circid(const packed_cell_t *cell, int wide_circ_ids);

View File

@ -518,7 +518,8 @@ bench_cell_ops(void)
for (i = 0; i < iters; ++i) {
char recognized = 0;
crypt_path_t *layer_hint = NULL;
relay_crypt(TO_CIRCUIT(or_circ), cell, d, &layer_hint, &recognized);
relay_decrypt_cell(TO_CIRCUIT(or_circ), cell, d,
&layer_hint, &recognized);
}
end = perftime();
printf("%sbound cells: %.2f ns per cell. (%.2f ns per byte of payload)\n",