Merge from 3.1: Issue #13703: add a way to randomize the hash values of basic types (str, bytes, datetime)
in order to make algorithmic complexity attacks on (e.g.) web apps much more complicated.
The environment variable PYTHONHASHSEED and the new command line flag -R control this
behavior.
diff --git a/Modules/_datetimemodule.c b/Modules/_datetimemodule.c
index 6ee5317..85c5c4d 100644
--- a/Modules/_datetimemodule.c
+++ b/Modules/_datetimemodule.c
@@ -2785,10 +2785,12 @@
register Py_hash_t x;
p = (unsigned char *) data;
- x = *p << 7;
+ x = _Py_HashSecret.prefix;
+ x ^= *p << 7;
while (--len >= 0)
x = (1000003*x) ^ *p++;
x ^= len;
+ x ^= _Py_HashSecret.suffix;
if (x == -1)
x = -2;