Add crypto_rand_int_range() and use it

Incidently, this fixes a bug where the maximum value was never used when
only using crypto_rand_int(). For instance this example below in
rendservice.c never gets to INTRO_POINT_LIFETIME_MAX_SECONDS.

  int intro_point_lifetime_seconds =
    INTRO_POINT_LIFETIME_MIN_SECONDS +
    crypto_rand_int(INTRO_POINT_LIFETIME_MAX_SECONDS -
                    INTRO_POINT_LIFETIME_MIN_SECONDS);

Signed-off-by: David Goulet <dgoulet@ev0ke.net>

1 files changed, 4 insertions, 2 deletions

diff --git a/src/or/entrynodes.c b/src/or/entrynodes.c
index 9663f34002..9f07d5ad69 100644
--- a/src/or/entrynodes.c
+++ b/src/or/entrynodes.c
@@ -440,7 +440,8 @@ add_an_entry_guard(const node_t *chosen, int reset_status, int prepend,
    * don't all select them on the same day, and b) avoid leaving a
    * precise timestamp in the state file about when we first picked
    * this guard. For details, see the Jan 2010 or-dev thread. */
-  entry->chosen_on_date = time(NULL) - crypto_rand_int(3600*24*30);
+  time_t now = time(NULL);
+  entry->chosen_on_date = crypto_rand_int_range(now - 3600*24*30, now);
   entry->chosen_by_version = tor_strdup(VERSION);
 
   /* Are we picking this guard because all of our current guards are
@@ -1439,8 +1440,9 @@ entry_guards_parse_state(or_state_t *state, int set, char **msg)
        }
      } else {
        if (state_version) {
+         time_t now = time(NULL);
+         e->chosen_on_date = crypto_rand_int_range(now - 3600*24*30, now);
          e->chosen_by_version = tor_strdup(state_version);
-         e->chosen_on_date = time(NULL) - crypto_rand_int(3600*24*30);
        }
      }
      if (e->path_bias_disabled && !e->bad_since)