hsearch: add seed to prevent another CVE-2012-3505 instance

master
rofl0r 2020-09-15 20:28:19 +01:00
parent 155bfbbe87
commit 5779ba8697
1 changed files with 6 additions and 4 deletions

View File

@ -48,6 +48,7 @@ struct htab {
struct elem *elems;
size_t mask;
size_t used;
size_t seed;
};
#define MINSIZE 8
@ -64,10 +65,10 @@ struct htab {
#define STRCMP(X, Y) strcmp(X, Y)
#endif
static size_t keyhash(const char *k)
static size_t keyhash(const char *k, size_t seed)
{
const unsigned char *p = (const void *)k;
size_t h = 0;
size_t h = seed;
while (*p)
h = 31*h + LOWER_OR_NOT(*p++);
@ -127,6 +128,7 @@ struct htab *htab_create(size_t nel)
free(r);
r = 0;
}
r->seed = rand();
return r;
}
@ -138,7 +140,7 @@ void htab_destroy(struct htab *htab)
static htab_entry *htab_find_item(struct htab *htab, const char* key)
{
size_t hash = keyhash(key);
size_t hash = keyhash(key, htab->seed);
struct elem *e = lookup(htab, key, hash);
if (e->item.key) {
@ -164,7 +166,7 @@ int htab_delete(struct htab *htab, const char* key)
int htab_insert(struct htab *htab, char* key, htab_value value)
{
size_t hash = keyhash(key);
size_t hash = keyhash(key, htab->seed);
struct elem *e = lookup(htab, key, hash);
if(e->item.key) {
/* it's not allowed to overwrite existing data */