Improve API of routerinfo_incompatible_with_extrainfo()

This API change makes it so that routerinfo_incompatible...() no
longer takes a routerinfo_t, so that it's obvious that it should
only look at fields from the signed_descriptor_t.

This change should prevent a recurrence of #17150.
This commit is contained in:
Nick Mathewson 2016-05-17 13:24:01 -04:00
parent 49ff09aef2
commit 00f74e0372
4 changed files with 19 additions and 16 deletions

View File

@ -691,12 +691,14 @@ dirserv_add_descriptor(routerinfo_t *ri, const char **msg, const char *source)
static was_router_added_t
dirserv_add_extrainfo(extrainfo_t *ei, const char **msg)
{
const routerinfo_t *ri;
routerinfo_t *ri;
int r;
tor_assert(msg);
*msg = NULL;
ri = router_get_by_id_digest(ei->cache_info.identity_digest);
/* Needs to be mutable so routerinfo_incompatible_with_extrainfo
* can mess with some of the flags in ri->cache_info. */
ri = router_get_mutable_by_digest(ei->cache_info.identity_digest);
if (!ri) {
*msg = "No corresponding router descriptor for extra-info descriptor";
extrainfo_free(ei);
@ -716,7 +718,8 @@ dirserv_add_extrainfo(extrainfo_t *ei, const char **msg)
return ROUTER_BAD_EI;
}
if ((r = routerinfo_incompatible_with_extrainfo(ri, ei, NULL, msg))) {
if ((r = routerinfo_incompatible_with_extrainfo(ri->identity_pkey, ei,
&ri->cache_info, msg))) {
extrainfo_free(ei);
return r < 0 ? ROUTER_IS_ALREADY_KNOWN : ROUTER_BAD_EI;
}

View File

@ -2072,7 +2072,8 @@ router_build_fresh_descriptor(routerinfo_t **r, extrainfo_t **e)
ri->cache_info.signed_descriptor_digest);
if (ei) {
tor_assert(! routerinfo_incompatible_with_extrainfo(ri, ei, NULL, NULL));
tor_assert(! routerinfo_incompatible_with_extrainfo(ri->identity_pkey, ei,
&ri->cache_info, NULL));
}
*r = ri;

View File

@ -2900,7 +2900,7 @@ extrainfo_insert,(routerlist_t *rl, extrainfo_t *ei, int warn_if_incompatible))
"Mismatch in digest in extrainfo map.");
goto done;
}
if (routerinfo_incompatible_with_extrainfo(ri, ei, sd,
if (routerinfo_incompatible_with_extrainfo(ri->identity_pkey, ei, sd,
&compatibility_error_msg)) {
char d1[HEX_DIGEST_LEN+1], d2[HEX_DIGEST_LEN+1];
r = (ri->cache_info.extrainfo_is_bogus) ?
@ -4901,9 +4901,9 @@ router_differences_are_cosmetic(const routerinfo_t *r1, const routerinfo_t *r2)
/** Check whether <b>sd</b> describes a router descriptor compatible with the
* extrainfo document <b>ei</b>.
*
* <b>ri</b> (which must also be provided) is the full routerinfo corresponding
* to the same router -- but note that it might not refer to the same specific
* descriptor as sd.
* <b>identity_pkey</b> (which must also be provided) is RSA1024 identity key
* for the router. We use it to check the signature of the extrainfo document,
* if it has not already been checked.
*
* If no router is compatible with <b>ei</b>, <b>ei</b> should be
* dropped. Return 0 for "compatible", return 1 for "reject, and inform
@ -4915,16 +4915,15 @@ router_differences_are_cosmetic(const routerinfo_t *r1, const routerinfo_t *r2)
* but the extrainfo was nonetheless incompatible.
**/
int
routerinfo_incompatible_with_extrainfo(const routerinfo_t *ri,
routerinfo_incompatible_with_extrainfo(const crypto_pk_t *identity_pkey,
extrainfo_t *ei,
signed_descriptor_t *sd,
const char **msg)
{
int digest_matches, digest256_matches, r=1;
tor_assert(ri);
tor_assert(identity_pkey);
tor_assert(sd);
tor_assert(ei);
if (!sd)
sd = (signed_descriptor_t*)&ri->cache_info;
if (ei->bad_sig) {
if (msg) *msg = "Extrainfo signature was bad, or signed with wrong key.";
@ -4942,7 +4941,7 @@ routerinfo_incompatible_with_extrainfo(const routerinfo_t *ri,
/* The identity must match exactly to have been generated at the same time
* by the same router. */
if (tor_memneq(ri->cache_info.identity_digest,
if (tor_memneq(sd->identity_digest,
ei->cache_info.identity_digest,
DIGEST_LEN)) {
if (msg) *msg = "Extrainfo nickname or identity did not match routerinfo";
@ -4956,7 +4955,7 @@ routerinfo_incompatible_with_extrainfo(const routerinfo_t *ri,
if (ei->pending_sig) {
char signed_digest[128];
if (crypto_pk_public_checksig(ri->identity_pkey,
if (crypto_pk_public_checksig(identity_pkey,
signed_digest, sizeof(signed_digest),
ei->pending_sig, ei->pending_sig_len) != DIGEST_LEN ||
tor_memneq(signed_digest, ei->cache_info.signed_descriptor_digest,
@ -4967,7 +4966,7 @@ routerinfo_incompatible_with_extrainfo(const routerinfo_t *ri,
goto err; /* Bad signature, or no match. */
}
ei->cache_info.send_unencrypted = ri->cache_info.send_unencrypted;
ei->cache_info.send_unencrypted = sd->send_unencrypted;
tor_free(ei->pending_sig);
}

View File

@ -187,7 +187,7 @@ void update_extrainfo_downloads(time_t now);
void router_reset_descriptor_download_failures(void);
int router_differences_are_cosmetic(const routerinfo_t *r1,
const routerinfo_t *r2);
int routerinfo_incompatible_with_extrainfo(const routerinfo_t *ri,
int routerinfo_incompatible_with_extrainfo(const crypto_pk_t *ri,
extrainfo_t *ei,
signed_descriptor_t *sd,
const char **msg);