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| author | Ravi Teja P <rvteja92@gmail.com> | 2020-06-29 17:39:29 (GMT) |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2020-06-29 17:39:29 (GMT) |
| commit | b30ee26e366bf509b7538d79bfec6c6d38d53f28 (patch) | |
| tree | 83f94a2f45115a972cecf8eba556de4bfa03235a | |
| parent | a3ad95dd2176b529fb6a9f763955b5cc1b499dbb (diff) | |
| download | cpython-b30ee26e366bf509b7538d79bfec6c6d38d53f28.zip cpython-b30ee26e366bf509b7538d79bfec6c6d38d53f28.tar.gz cpython-b30ee26e366bf509b7538d79bfec6c6d38d53f28.tar.bz2 | |
bpo-41004: Resolve hash collisions for IPv4Interface and IPv6Interface (GH-21033)
The __hash__() methods of classes IPv4Interface and IPv6Interface had issue
of generating constant hash values of 32 and 128 respectively causing hash collisions.
The fix uses the hash() function to generate hash values for the objects
instead of XOR operation
| -rw-r--r-- | Lib/ipaddress.py | 4 | ||||
| -rw-r--r-- | Lib/test/test_ipaddress.py | 12 | ||||
| -rw-r--r-- | Misc/NEWS.d/next/Security/2020-06-29-16-02-29.bpo-41004.ovF0KZ.rst | 1 |
3 files changed, 15 insertions, 2 deletions
diff --git a/Lib/ipaddress.py b/Lib/ipaddress.py index 6e5a754..75b4c35 100644 --- a/Lib/ipaddress.py +++ b/Lib/ipaddress.py @@ -1420,7 +1420,7 @@ class IPv4Interface(IPv4Address): return False def __hash__(self): - return self._ip ^ self._prefixlen ^ int(self.network.network_address) + return hash((self._ip, self._prefixlen, int(self.network.network_address))) __reduce__ = _IPAddressBase.__reduce__ @@ -2120,7 +2120,7 @@ class IPv6Interface(IPv6Address): return False def __hash__(self): - return self._ip ^ self._prefixlen ^ int(self.network.network_address) + return hash((self._ip, self._prefixlen, int(self.network.network_address))) __reduce__ = _IPAddressBase.__reduce__ diff --git a/Lib/test/test_ipaddress.py b/Lib/test/test_ipaddress.py index 6d5814c..3c07008 100644 --- a/Lib/test/test_ipaddress.py +++ b/Lib/test/test_ipaddress.py @@ -2548,6 +2548,18 @@ class IpaddrUnitTest(unittest.TestCase): sixtofouraddr.sixtofour) self.assertFalse(bad_addr.sixtofour) + # issue41004 Hash collisions in IPv4Interface and IPv6Interface + def testV4HashIsNotConstant(self): + ipv4_address1 = ipaddress.IPv4Interface("1.2.3.4") + ipv4_address2 = ipaddress.IPv4Interface("2.3.4.5") + self.assertNotEqual(ipv4_address1.__hash__(), ipv4_address2.__hash__()) + + # issue41004 Hash collisions in IPv4Interface and IPv6Interface + def testV6HashIsNotConstant(self): + ipv6_address1 = ipaddress.IPv6Interface("2001:658:22a:cafe:200:0:0:1") + ipv6_address2 = ipaddress.IPv6Interface("2001:658:22a:cafe:200:0:0:2") + self.assertNotEqual(ipv6_address1.__hash__(), ipv6_address2.__hash__()) + if __name__ == '__main__': unittest.main() diff --git a/Misc/NEWS.d/next/Security/2020-06-29-16-02-29.bpo-41004.ovF0KZ.rst b/Misc/NEWS.d/next/Security/2020-06-29-16-02-29.bpo-41004.ovF0KZ.rst new file mode 100644 index 0000000..1380b31 --- /dev/null +++ b/Misc/NEWS.d/next/Security/2020-06-29-16-02-29.bpo-41004.ovF0KZ.rst @@ -0,0 +1 @@ +The __hash__() methods of ipaddress.IPv4Interface and ipaddress.IPv6Interface incorrectly generated constant hash values of 32 and 128 respectively. This resulted in always causing hash collisions. The fix uses hash() to generate hash values for the tuple of (address, mask length, network address). |