commit 0b819a2a7c8a79a222ffd8af0b239133f9becd7c Author: Nick Mathewson nickm@torproject.org Date: Fri Oct 24 09:19:49 2014 -0400

Enforce more correspondence between ri and ei

In particular, they have to list the same ed25519 certificate, and the SHA256 digest of the ei needs to match. --- src/or/routerlist.c | 17 ++++++++++++++++- src/or/torcert.c | 21 +++++++++++++++++++++ src/or/torcert.h | 2 ++ 3 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/src/or/routerlist.c b/src/or/routerlist.c index b2784ae..a531051 100644 --- a/src/or/routerlist.c +++ b/src/or/routerlist.c @@ -4906,7 +4906,7 @@ routerinfo_incompatible_with_extrainfo(const routerinfo_t *ri, signed_descriptor_t *sd, const char **msg) { - int digest_matches, r=1; + int digest_matches, digest256_matches, r=1; tor_assert(ri); tor_assert(ei); if (!sd) @@ -4919,6 +4919,11 @@ routerinfo_incompatible_with_extrainfo(const routerinfo_t *ri,

digest_matches = tor_memeq(ei->cache_info.signed_descriptor_digest, sd->extra_info_digest, DIGEST_LEN); + /* Set digest256_matches to 1 if the digest is correct, or if no + * digest256 was in the ri. */ + digest256_matches = tor_memeq(ei->digest256, + ri->extra_info_digest256, DIGEST256_LEN); + digest256_matches |= tor_mem_is_zero(ri->extra_info_digest256, DIGEST256_LEN);

/* The identity must match exactly to have been generated at the same time * by the same router. */ @@ -4929,6 +4934,11 @@ routerinfo_incompatible_with_extrainfo(const routerinfo_t *ri, goto err; /* different servers */ }

+ if (! tor_cert_opt_eq(ri->signing_key_cert, ei->signing_key_cert)) { + if (msg) *msg = "Extrainfo signing key cert didn't match routerinfo"; + goto err; /* different servers */ + } + if (ei->pending_sig) { char signed_digest[128]; if (crypto_pk_public_checksig(ri->identity_pkey, @@ -4955,6 +4965,11 @@ routerinfo_incompatible_with_extrainfo(const routerinfo_t *ri, goto err; }

+ if (!digest256_matches) { + if (msg) *msg = "Extrainfo digest did not match digest256 from routerdesc"; + goto err; /* Digest doesn't match declared value. */ + } + if (!digest_matches) { if (msg) *msg = "Extrainfo digest did not match value from routerdesc"; goto err; /* Digest doesn't match declared value. */ diff --git a/src/or/torcert.c b/src/or/torcert.c index 8fe9c12..1534730 100644 --- a/src/or/torcert.c +++ b/src/or/torcert.c @@ -216,3 +216,24 @@ tor_cert_dup(const tor_cert_t *cert) return newcert; }

+/** Return true iff cert1 and cert2 are the same cert. */ +int +tor_cert_eq(const tor_cert_t *cert1, const tor_cert_t *cert2) +{ + tor_assert(cert1); + tor_assert(cert2); + return cert1->encoded_len == cert2->encoded_len && + tor_memeq(cert1->encoded, cert2->encoded, cert1->encoded_len); +} + +/** Return true iff cert1 and cert2 are the same cert, or if they are both + * NULL. */ +int +tor_cert_opt_eq(const tor_cert_t *cert1, const tor_cert_t *cert2) +{ + if (cert1 == NULL && cert2 == NULL) + return 1; + if (!cert1 || !cert2) + return 0; + return tor_cert_eq(cert1, cert2); +} diff --git a/src/or/torcert.h b/src/or/torcert.h index ae9361f..4680ca6 100644 --- a/src/or/torcert.h +++ b/src/or/torcert.h @@ -64,6 +64,8 @@ int tor_cert_checksig(tor_cert_t *cert, const ed25519_public_key_t *pubkey, time_t now);

tor_cert_t *tor_cert_dup(const tor_cert_t *cert); +int tor_cert_eq(const tor_cert_t *cert1, const tor_cert_t *cert2); +int tor_cert_opt_eq(const tor_cert_t *cert1, const tor_cert_t *cert2);

#endif