#ifdef USE_REENTRANT_API
Perl_reentrant_init(aTHX);
#endif
-#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 you set PL_hash_seed (and presumably also PL_hash_seed_set)
- * yourself, it is your responsibility to provide a good random seed!
- * You can also define PERL_HASH_SEED in compile time, see hv.h.
- *
- * XXX: fix this comment */
if (PL_hash_seed_set == FALSE) {
+ /* Initialize the hash seed and state at startup. This must be
+ * done very early, before ANY hashes are constructed, and once
+ * setup is fixed for the lifetime of the process.
+ *
+ * If you decide to disable the seeding process you should choose
+ * a suitable seed yourself and define PERL_HASH_SEED to a well chosen
+ * string. See hv_func.h for details.
+ */
+#if defined(USE_HASH_SEED)
+ /* get the hash seed from the environment or from an RNG */
Perl_get_hash_seed(aTHX_ PL_hash_seed);
+#else
+ /* they want a hard coded seed, check that it is long enough */
+ assert( strlen(PERL_HASH_SEED) >= PERL_HASH_SEED_BYTES );
+#endif
+
+ /* now we use the chosen seed to initialize the state -
+ * in some configurations this may be a relatively speaking
+ * expensive operation, but we only have to do it once at startup */
+ PERL_HASH_SEED_STATE(PERL_HASH_SEED,PL_hash_state);
+
+#ifdef PERL_USE_SINGLE_CHAR_HASH_CACHE
+ /* we can build a special cache for 0/1 byte keys, if people choose
+ * I suspect most of the time it is not worth it */
+ {
+ char str[2]="\0";
+ int i;
+ for (i=0;i<256;i++) {
+ str[0]= i;
+ PERL_HASH_WITH_STATE(PL_hash_state,PL_hash_chars[i],str,1);
+ }
+ PERL_HASH_WITH_STATE(PL_hash_state,PL_hash_chars[256],str,0);
+ }
+#endif
+ /* at this point we have initialezed the hash function, and we can start
+ * constructing hashes */
PL_hash_seed_set= TRUE;
}
-#endif /* #if defined(USE_HASH_SEED) || defined(USE_HASH_SEED_EXPLICIT) */
-
/* Note that strtab is a rather special HV. Assumptions are made
about not iterating on it, and not adding tie magic to it.
It is properly deallocated in perl_destruct() */
PL_strtab = newHV();
+ /* SHAREKEYS tells us that the hash has its keys shared with PL_strtab,
+ * which is not the case with PL_strtab itself */
HvSHAREKEYS_off(PL_strtab); /* mandatory */
- hv_ksplit(PL_strtab, 512);
+ hv_ksplit(PL_strtab, 1 << 11);
Zero(PL_sv_consts, SV_CONSTS_COUNT, SV*);
#ifndef MULTIPLICITY
PERL_UNUSED_ARG(my_perl);
#endif
-#if (defined(USE_HASH_SEED) || defined(USE_HASH_SEED_EXPLICIT) || defined(USE_HASH_SEED_DEBUG)) && !defined(NO_PERL_HASH_SEED_DEBUG)
+#if (defined(USE_HASH_SEED) || defined(USE_HASH_SEED_DEBUG)) && !defined(NO_PERL_HASH_SEED_DEBUG)
{
const char * const s = PerlEnv_getenv("PERL_HASH_SEED_DEBUG");
PerlIO_printf(Perl_debug_log, "\n");
}
}
-#endif /* #if (defined(USE_HASH_SEED) || defined(USE_HASH_SEED_EXPLICIT) ... */
+#endif /* #if (defined(USE_HASH_SEED) ... */
#ifdef __amigaos4__
{
# ifdef USE_FAST_STDIO
" USE_FAST_STDIO"
# endif
-# ifdef USE_HASH_SEED_EXPLICIT
- " USE_HASH_SEED_EXPLICIT"
-# endif
# ifdef USE_LOCALE
" USE_LOCALE"
# endif