Hand-conversion and audit phase of memcmp transition

Here I looked at the results of the automated conversion and cleaned
them up as follows:

   If there was a tor_memcmp or tor_memeq that was in fact "safe"[*] I
   changed it to a fast_memcmp or fast_memeq.

   Otherwise if there was a tor_memcmp that could turn into a
   tor_memneq or tor_memeq, I converted it.

This wants close attention.

[*] I'm erring on the side of caution here, and leaving some things
as tor_memcmp that could in my opinion use the data-dependent
fast_memcmp variant.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/or/rendmid.c b/src/or/rendmid.c
index c8e614d78..d73f0a1ba 100644
--- a/src/or/rendmid.c
+++ b/src/or/rendmid.c
@@ -57,7 +57,7 @@ rend_mid_establish_intro(or_circuit_t *circ, const uint8_t *request,
     log_warn(LD_BUG, "Internal error computing digest.");
     goto err;
   }
-  if (tor_memcmp(expected_digest, request+2+asn1len, DIGEST_LEN)) {
+  if (tor_memneq(expected_digest, request+2+asn1len, DIGEST_LEN)) {
     log_warn(LD_PROTOCOL, "Hash of session info was not as expected.");
     reason = END_CIRC_REASON_TORPROTOCOL;
     goto err;