traverseda
/
cpython
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

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
This commit is contained in:
Ravi Teja P 2020-06-29 23:09:29 +05:30 committed by GitHub
parent a3ad95dd21
commit b30ee26e36
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
3 changed files with 15 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
Lib/ipaddress.py
View File

@ -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__

12
Lib/test/test_ipaddress.py
View File

@ -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()

1
Misc/NEWS.d/next/Security/2020-06-29-16-02-29.bpo-41004.ovF0KZ.rst Normal file
View File

@ -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).