Use SHA256 in the replaycache, rather than SHA1

This migrates away from SHA1, and provides further hash flooding
protection on top of the randomised siphash implementation.

Add unit tests to make sure that different inputs don't have the
same hash.

1 files changed, 13 insertions, 13 deletions

diff --git a/src/or/replaycache.c b/src/or/replaycache.c
index 569e0736cb..82e5c44d3d 100644
--- a/src/or/replaycache.c
+++ b/src/or/replaycache.c
@@ -23,7 +23,7 @@ replaycache_free(replaycache_t *r)
     return;
   }
 
-  if (r->digests_seen) digestmap_free(r->digests_seen, tor_free_);
+  if (r->digests_seen) digest256map_free(r->digests_seen, tor_free_);
 
   tor_free(r);
 }
@@ -54,7 +54,7 @@ replaycache_new(time_t horizon, time_t interval)
   r->scrub_interval = interval;
   r->scrubbed = 0;
   r->horizon = horizon;
-  r->digests_seen = digestmap_new();
+  r->digests_seen = digest256map_new();
 
  err:
   return r;
@@ -69,7 +69,7 @@ replaycache_add_and_test_internal(
     time_t *elapsed)
 {
   int rv = 0;
-  char digest[DIGEST_LEN];
+  uint8_t digest[DIGEST256_LEN];
   time_t *access_time;
 
   /* sanity check */
@@ -80,10 +80,10 @@ replaycache_add_and_test_internal(
   }
 
   /* compute digest */
-  crypto_digest(digest, (const char *)data, len);
+  crypto_digest256((char *)digest, (const char *)data, len, DIGEST_SHA256);
 
   /* check map */
-  access_time = digestmap_get(r->digests_seen, digest);
+  access_time = digest256map_get(r->digests_seen, digest);
 
   /* seen before? */
   if (access_time != NULL) {
@@ -114,7 +114,7 @@ replaycache_add_and_test_internal(
     /* No, so no hit and update the digest map with the current time */
     access_time = tor_malloc(sizeof(*access_time));
     *access_time = present;
-    digestmap_set(r->digests_seen, digest, access_time);
+    digest256map_set(r->digests_seen, digest, access_time);
   }
 
   /* now scrub the cache if it's time */
@@ -130,8 +130,8 @@ replaycache_add_and_test_internal(
 STATIC void
 replaycache_scrub_if_needed_internal(time_t present, replaycache_t *r)
 {
-  digestmap_iter_t *itr = NULL;
-  const char *digest;
+  digest256map_iter_t *itr = NULL;
+  const uint8_t *digest;
   void *valp;
   time_t *access_time;
 
@@ -149,19 +149,19 @@ replaycache_scrub_if_needed_internal(time_t present, replaycache_t *r)
   if (r->horizon == 0) return;
 
   /* okay, scrub time */
-  itr = digestmap_iter_init(r->digests_seen);
-  while (!digestmap_iter_done(itr)) {
-    digestmap_iter_get(itr, &digest, &valp);
+  itr = digest256map_iter_init(r->digests_seen);
+  while (!digest256map_iter_done(itr)) {
+    digest256map_iter_get(itr, &digest, &valp);
     access_time = (time_t *)valp;
     /* aged out yet? */
     if (*access_time < present - r->horizon) {
       /* Advance the iterator and remove this one */
-      itr = digestmap_iter_next_rmv(r->digests_seen, itr);
+      itr = digest256map_iter_next_rmv(r->digests_seen, itr);
       /* Free the value removed */
       tor_free(access_time);
     } else {
       /* Just advance the iterator */
-      itr = digestmap_iter_next(r->digests_seen, itr);
+      itr = digest256map_iter_next(r->digests_seen, itr);
     }
   }