diff options
Diffstat (limited to 'Objects')
| -rw-r--r-- | Objects/object.c | 13 | ||||
| -rw-r--r-- | Objects/unicodeobject.c | 12 |
2 files changed, 19 insertions, 6 deletions
diff --git a/Objects/object.c b/Objects/object.c index 8134825..bb18d47 100644 --- a/Objects/object.c +++ b/Objects/object.c @@ -759,10 +759,19 @@ _Py_HashBytes(unsigned char *p, Py_ssize_t len) Py_uhash_t x; Py_ssize_t i; - x = (Py_uhash_t) *p << 7; + /* + We make the hash of the empty string be 0, rather than using + (prefix ^ suffix), since this slightly obfuscates the hash secret + */ + if (len == 0) { + return 0; + } + x = (Py_uhash_t) _Py_HashSecret.prefix; + x ^= (Py_uhash_t) *p << 7; for (i = 0; i < len; i++) x = (_PyHASH_MULTIPLIER * x) ^ (Py_uhash_t) *p++; x ^= (Py_uhash_t) len; + x ^= (Py_uhash_t) _Py_HashSecret.suffix; if (x == -1) x = -2; return x; @@ -776,6 +785,8 @@ PyObject_HashNotImplemented(PyObject *v) return -1; } +_Py_HashSecret_t _Py_HashSecret; + Py_hash_t PyObject_Hash(PyObject *v) { diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c index 07d3eb8..716ca3f 100644 --- a/Objects/unicodeobject.c +++ b/Objects/unicodeobject.c @@ -11221,11 +11221,12 @@ unicode_hash(PyObject *self) len = PyUnicode_GET_LENGTH(self); /* The hash function as a macro, gets expanded three times below. */ -#define HASH(P) \ - x = (Py_uhash_t)*P << 7; \ - while (--len >= 0) \ - x = (_PyHASH_MULTIPLIER*x) ^ (Py_uhash_t)*P++; +#define HASH(P) \ + x ^= (Py_uhash_t) *P << 7; \ + while (--len >= 0) \ + x = (_PyHASH_MULTIPLIER * x) ^ (Py_uhash_t) *P++; \ + x = (Py_uhash_t) _Py_HashSecret.prefix; switch (PyUnicode_KIND(self)) { case PyUnicode_1BYTE_KIND: { const unsigned char *c = PyUnicode_1BYTE_DATA(self); @@ -11246,7 +11247,8 @@ unicode_hash(PyObject *self) break; } } - x ^= (Py_uhash_t)PyUnicode_GET_LENGTH(self); + x ^= (Py_uhash_t) PyUnicode_GET_LENGTH(self); + x ^= (Py_uhash_t) _Py_HashSecret.suffix; if (x == -1) x = -2; |