MEDIUM: init: fall back to ha_random64_pair_hashed() for the cluster secret

The cluster secret, when SSL is not working, used to involve a mix of
calls to ha_random64() and random() to mask the bits that we didn't want
to see leaked. Let's now simply fall back to ha_random64_pair_hashed()
that does a much better job.

diff --git a/src/haproxy.c b/src/haproxy.c
index 51d1fc0de5d37158e06c15a64b202ea297d9e0b2..cd1dbe46445fee449981367ebbb4707e2ecfebe2 100644 (file)
--- a/src/haproxy.c
+++ b/src/haproxy.c
@@ -1926,16 +1926,14 @@ static void dump_registered_keywords(void)
 
 /* Generate a random cluster-secret in case the setting is not provided in the
  * configuration. This allows to use features which rely on it albeit with some
- * limitations. The function doesn't (solely) use ha_random64() because this
- * secret is permanent, and ha_random64() can easily be leaked at various
- * places.
+ * limitations. The function prefers RAND_bytes() if available, otherwise falls
+ * back to ha_random64_pair_hashed().
  */
 static void generate_random_cluster_secret()
 {
        /* used as a default random cluster-secret if none defined. */
        union {
                uint64_t by64[2];
-               uint32_t by32[4];
                uchar    by8[16];
        } rand;
 
@@ -1948,12 +1946,7 @@ static void generate_random_cluster_secret()
 #endif
        {
                /* no SSL or not working, fall back to other sources */
-               rand.by64[0] = ha_random64();
-               rand.by64[1] = ha_random64();
-               rand.by32[0] ^= ((random() & 0x00ffff00) << 8) | ((random() & 0x00ffff00) >> 8);
-               rand.by32[1] ^= ((random() & 0x00ffff00) << 8) | ((random() & 0x00ffff00) >> 8);
-               rand.by32[2] ^= ((random() & 0x00ffff00) << 8) | ((random() & 0x00ffff00) >> 8);
-               rand.by32[3] ^= ((random() & 0x00ffff00) << 8) | ((random() & 0x00ffff00) >> 8);
+               ha_random64_pair_hashed(&rand.by64[0], &rand.by64[1]);
        }
 
        memcpy(global.cluster_secret, &rand, sizeof(rand));