Move the real INTRODUCE2 replay-detection cache into rend_intro_point_t

This commit is contained in:
Robert Ransom 2011-10-29 17:02:53 -07:00
parent 1eba4f0cc3
commit 1a52a947c5
4 changed files with 26 additions and 17 deletions

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@ -0,0 +1,7 @@
o Minor features:
- Move the replay-detection cache for the RSA-encrypted parts of
INTRODUCE2 cells to the introduction point data structures.
Previously, we would use one replay-detection cache per hidden
service. Required by fix for bug 3460.

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@ -3505,9 +3505,12 @@ typedef struct rend_intro_point_t {
* included in the last HS descriptor we generated. */
unsigned int listed_in_last_desc : 1;
/** (Service side only) The number of INTRODUCE2 cells this intro
* point's circuit has received. */
unsigned int introduction_count : 24;
/** (Service side only) A digestmap recording the INTRODUCE2 cells
* this intro point's circuit has received. Each key is the digest
* of the RSA-encrypted part of a received INTRODUCE2 cell; each
* value is a pointer to the time_t at which the cell was
* received. */
digestmap_t *accepted_intros;
/** (Service side only) The time at which this intro point was first
* published, or -1 if this intro point has not yet been

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@ -440,6 +440,11 @@ rend_intro_point_free(rend_intro_point_t *intro)
extend_info_free(intro->extend_info);
crypto_free_pk_env(intro->intro_key);
if (intro->accepted_intros != NULL) {
digestmap_free(intro->accepted_intros, _tor_free);
}
tor_free(intro);
}

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@ -1005,14 +1005,14 @@ rend_service_introduce(origin_circuit_t *circuit, const uint8_t *request,
if (!service->accepted_intros)
service->accepted_intros = digestmap_new();
if (!intro_point->accepted_intros)
intro_point->accepted_intros = digestmap_new();
{
char pkpart_digest[DIGEST_LEN];
/* Check for replay of PK-encrypted portion. It is slightly naughty to
use the same digestmap to check for this and for g^x replays, but
collisions are tremendously unlikely.
*/
/* Check for replay of PK-encrypted portion. */
crypto_digest(pkpart_digest, (char*)request+DIGEST_LEN, keylen);
access_time = digestmap_get(service->accepted_intros, pkpart_digest);
access_time = digestmap_get(intro_point->accepted_intros, pkpart_digest);
if (access_time != NULL) {
log_warn(LD_REND, "Possible replay detected! We received an "
"INTRODUCE2 cell with same PK-encrypted part %d seconds ago. "
@ -1021,14 +1021,7 @@ rend_service_introduce(origin_circuit_t *circuit, const uint8_t *request,
}
access_time = tor_malloc(sizeof(time_t));
*access_time = now;
digestmap_set(service->accepted_intros, pkpart_digest, access_time);
}
/* Record that we've received another INTRODUCE2 cell through this
* intro point. */
++(intro_point->introduction_count);
if (intro_point->introduction_count == 0) {
--(intro_point->introduction_count);
digestmap_set(intro_point->accepted_intros, pkpart_digest, access_time);
}
/* Next N bytes is encrypted with service key */
@ -1935,7 +1928,8 @@ intro_point_should_expire_now(rend_intro_point_t *intro,
return 1;
}
if (intro->introduction_count >= INTRO_POINT_LIFETIME_INTRODUCTIONS) {
if (digestmap_size(intro->accepted_intros) >=
INTRO_POINT_LIFETIME_INTRODUCTIONS) {
/* This intro point has been used too many times. Expire it now. */
return 1;
}