commit 00f74e0372a956f9db590e1cb2ddcfb265125023 Author: Nick Mathewson nickm@torproject.org Date: Tue May 17 13:24:01 2016 -0400
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. --- src/or/dirserv.c | 9 ++++++--- src/or/router.c | 3 ++- src/or/routerlist.c | 21 ++++++++++----------- src/or/routerlist.h | 2 +- 4 files changed, 19 insertions(+), 16 deletions(-)
diff --git a/src/or/dirserv.c b/src/or/dirserv.c index 01b08ca..ab77021 100644 --- a/src/or/dirserv.c +++ b/src/or/dirserv.c @@ -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; } diff --git a/src/or/router.c b/src/or/router.c index b3523ec..37ce9e7 100644 --- a/src/or/router.c +++ b/src/or/router.c @@ -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; diff --git a/src/or/routerlist.c b/src/or/routerlist.c index f75ec11..0f1fac7 100644 --- a/src/or/routerlist.c +++ b/src/or/routerlist.c @@ -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); }
diff --git a/src/or/routerlist.h b/src/or/routerlist.h index 200533f..bbe99f8 100644 --- a/src/or/routerlist.h +++ b/src/or/routerlist.h @@ -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);