diff options
Diffstat (limited to 'Objects')
| -rw-r--r-- | Objects/bytesobject.c | 12 | ||||
| -rw-r--r-- | Objects/object.c | 2 | ||||
| -rw-r--r-- | Objects/unicodeobject.c | 12 |
3 files changed, 24 insertions, 2 deletions
diff --git a/Objects/bytesobject.c b/Objects/bytesobject.c index f2ee131..e6ab440 100644 --- a/Objects/bytesobject.c +++ b/Objects/bytesobject.c @@ -899,11 +899,21 @@ bytes_hash(PyBytesObject *a) if (a->ob_shash != -1) return a->ob_shash; len = Py_SIZE(a); + /* + 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) { + a->ob_shash = 0; + return 0; + } p = (unsigned char *) a->ob_sval; - x = *p << 7; + x = _Py_HashSecret.prefix; + x ^= *p << 7; while (--len >= 0) x = (1000003*x) ^ *p++; x ^= Py_SIZE(a); + x ^= _Py_HashSecret.suffix; if (x == -1) x = -2; a->ob_shash = x; diff --git a/Objects/object.c b/Objects/object.c index ac57cd7..0b1c656 100644 --- a/Objects/object.c +++ b/Objects/object.c @@ -712,6 +712,8 @@ PyObject_HashNotImplemented(PyObject *v) return -1; } +_Py_HashSecret_t _Py_HashSecret; + long PyObject_Hash(PyObject *v) { diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c index 2cdbc0e..5986fb8 100644 --- a/Objects/unicodeobject.c +++ b/Objects/unicodeobject.c @@ -7344,11 +7344,21 @@ unicode_hash(PyUnicodeObject *self) if (self->hash != -1) return self->hash; len = Py_SIZE(self); + /* + 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) { + self->hash = 0; + return 0; + } p = self->str; - x = *p << 7; + x = _Py_HashSecret.prefix; + x ^= *p << 7; while (--len >= 0) x = (1000003*x) ^ *p++; x ^= Py_SIZE(self); + x ^= _Py_HashSecret.suffix; if (x == -1) x = -2; self->hash = x; |