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authorNicholas Clark <nick@ccl4.org>2003-10-16 21:10:27 +0000
committerNicholas Clark <nick@ccl4.org>2003-10-16 21:10:27 +0000
commit4b5190b5321b9b9e2ec46674b256120d4fdab72a (patch)
tree1e544d93aaa7feaa02a7944af04463c96a8acd7e /hv.h
parent4e380990fe579cbec68c15cb8ee072f2d6644a71 (diff)
downloadperl-4b5190b5321b9b9e2ec46674b256120d4fdab72a.tar.gz
Plan C for foiling the algorithmic complexity attack
(based on Chip's plan A (binary compatibility with 5.8.0 and 5.8.1), Chip's plan B (do something new inside the hv functions) and introspective sort) Provides infrastructure for hashes to change their hash function if necessary, and code in hsplit to detect pathalogical data and instigate a random rehashing. Needs refinement. Let's see how much smoke it creates. p4raw-id: //depot/perl@21471
Diffstat (limited to 'hv.h')
-rw-r--r--hv.h26
1 files changed, 26 insertions, 0 deletions
diff --git a/hv.h b/hv.h
index 4fa4239be9..1c7fcda241 100644
--- a/hv.h
+++ b/hv.h
@@ -89,6 +89,24 @@ struct xpvhv {
(hash) = (hash_PeRlHaSh + (hash_PeRlHaSh << 15)); \
} STMT_END
+#ifdef PERL_IN_HV_C
+#define PERL_HASH_INTERNAL(hash,str,len) \
+ STMT_START { \
+ register const char *s_PeRlHaSh_tmp = str; \
+ register const unsigned char *s_PeRlHaSh = (const unsigned char *)s_PeRlHaSh_tmp; \
+ register I32 i_PeRlHaSh = len; \
+ register U32 hash_PeRlHaSh = PL_new_hash_seed; \
+ while (i_PeRlHaSh--) { \
+ hash_PeRlHaSh += *s_PeRlHaSh++; \
+ hash_PeRlHaSh += (hash_PeRlHaSh << 10); \
+ hash_PeRlHaSh ^= (hash_PeRlHaSh >> 6); \
+ } \
+ hash_PeRlHaSh += (hash_PeRlHaSh << 3); \
+ hash_PeRlHaSh ^= (hash_PeRlHaSh >> 11); \
+ (hash) = (hash_PeRlHaSh + (hash_PeRlHaSh << 15)); \
+ } STMT_END
+#endif
+
/*
=head1 Hash Manipulation Functions
@@ -203,6 +221,10 @@ C<SV*>.
#define HvLAZYDEL_on(hv) (SvFLAGS(hv) |= SVphv_LAZYDEL)
#define HvLAZYDEL_off(hv) (SvFLAGS(hv) &= ~SVphv_LAZYDEL)
+#define HvREHASH(hv) (SvFLAGS(hv) & SVphv_REHASH)
+#define HvREHASH_on(hv) (SvFLAGS(hv) |= SVphv_REHASH)
+#define HvREHASH_off(hv) (SvFLAGS(hv) &= ~SVphv_REHASH)
+
/* Maybe amagical: */
/* #define HV_AMAGICmb(hv) (SvFLAGS(hv) & (SVpgv_badAM | SVpgv_AM)) */
@@ -224,6 +246,7 @@ C<SV*>.
#define HeKLEN(he) HEK_LEN(HeKEY_hek(he))
#define HeKUTF8(he) HEK_UTF8(HeKEY_hek(he))
#define HeKWASUTF8(he) HEK_WASUTF8(HeKEY_hek(he))
+#define HeKREHASH(he) HEK_REHASH(HeKEY_hek(he))
#define HeKLEN_UTF8(he) (HeKUTF8(he) ? -HeKLEN(he) : HeKLEN(he))
#define HeKFLAGS(he) HEK_FLAGS(HeKEY_hek(he))
#define HeVAL(he) (he)->hent_val
@@ -254,6 +277,7 @@ C<SV*>.
#define HVhek_UTF8 0x01 /* Key is utf8 encoded. */
#define HVhek_WASUTF8 0x02 /* Key is bytes here, but was supplied as utf8. */
+#define HVhek_REHASH 0x04 /* This key is in an hv using a custom HASH . */
#define HVhek_FREEKEY 0x100 /* Internal flag to say key is malloc()ed. */
#define HVhek_PLACEHOLD 0x200 /* Internal flag to create placeholder.
* (may change, but Storable is a core module) */
@@ -265,6 +289,8 @@ C<SV*>.
#define HEK_WASUTF8(hek) (HEK_FLAGS(hek) & HVhek_WASUTF8)
#define HEK_WASUTF8_on(hek) (HEK_FLAGS(hek) |= HVhek_WASUTF8)
#define HEK_WASUTF8_off(hek) (HEK_FLAGS(hek) &= ~HVhek_WASUTF8)
+#define HEK_REHASH(hek) (HEK_FLAGS(hek) & HVhek_REHASH)
+#define HEK_REHASH_on(hek) (HEK_FLAGS(hek) |= HVhek_REHASH)
/* calculate HV array allocation */
#if defined(STRANGE_MALLOC) || defined(MYMALLOC)