Chicken out: the hash randomisation is not on by default.

We switch over to the explicit mode: in other words, if
the $ENV{PERL_HASH_SEED} is on, we randomise.  Also, we
randomise only if PL_hash_seed_set is FALSE (this means
one can use PERL_HASH() before perl_run.)  Also, since
now PERL_HASH_SEED is okay even under -T, all should be fine.
(Ha!)

p4raw-id: //depot/perl@20135

1 files changed, 11 insertions, 24 deletions

diff --git a/perl.c b/perl.c
index 173848926f..32e046989c 100644
--- a/perl.c
+++ b/perl.c
@@ -900,31 +900,18 @@ setuid perl scripts securely.\n");
 #if defined(USE_HASH_SEED) || defined(USE_HASH_SEED_EXPLICIT)
     /* [perl #22371] Algorimic Complexity Attack on Perl 5.6.1, 5.8.0
      * This MUST be done before any hash stores or fetches take place. */
+    if (!PL_hash_seed_set)
+	 PL_hash_seed = get_seed();
     {
-       char *s = PerlEnv_getenv("PERL_HASH_SEED");
-       if (s)
-           while (isSPACE(*s)) s++;
-       if (s && isDIGIT(*s))
-           PL_hash_seed = (UV)Atoul(s);
-#ifndef USE_HASH_SEED_EXPLICIT
-       else {
-           /* Compute a random seed */
-           (void)seedDrand01((Rand_seed_t)seed());
-           PL_srand_called = TRUE;
-           PL_hash_seed = (UV)(Drand01() * (NV)UV_MAX);
-#if RANDBITS < (UVSIZE * 8)
-	   /* Since there are not enough randbits to to reach all
-	    * the bits of a UV, the low bits might need extra
-	    * help.  Sum in another random number that will
-	    * fill in the low bits. */
-	   PL_hash_seed +=
-	     (UV)(Drand01() * (NV)((1 << ((UVSIZE * 8 - RANDBITS))) - 1));
-#endif /* RANDBITS < (UVSIZE * 8) */
-       }
-#endif /* #ifndef USE_HASH_SEED_EXPLICIT */
-       if ((s = PerlEnv_getenv("PERL_HASH_SEED_DEBUG")))
-	   PerlIO_printf(Perl_debug_log, "HASH_SEED = %"UVuf"\n",
-			 PL_hash_seed);
+	 char *s = PerlEnv_getenv("PERL_HASH_SEED_DEBUG");
+
+	 if (s) {
+	      int i = atoi(s);
+
+	      if (i == 1)
+		   PerlIO_printf(Perl_debug_log, "HASH_SEED = %"UVuf"\n",
+				 PL_hash_seed);
+	 }
     }
 #endif /* #if defined(USE_HASH_SEED) || defined(USE_HASH_SEED_EXPLICIT) */