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authorMiss Islington (bot) <31488909+miss-islington@users.noreply.github.com>2020-06-29 18:12:50 (GMT)
committerGitHub <noreply@github.com>2020-06-29 18:12:50 (GMT)
commitdc8ce8ead182de46584cc1ed8a8c51d48240cbd5 (patch)
tree1db73719f1165dddb6c97a759fdd45bb3f776e49
parent7731139b7af655b9f5df6d1b5493f8dfdf41d569 (diff)
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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 (cherry picked from commit b30ee26e366bf509b7538d79bfec6c6d38d53f28) Co-authored-by: Ravi Teja P <rvteja92@gmail.com>
-rw-r--r--Lib/ipaddress.py4
-rw-r--r--Lib/test/test_ipaddress.py12
-rw-r--r--Misc/NEWS.d/next/Security/2020-06-29-16-02-29.bpo-41004.ovF0KZ.rst1
3 files changed, 15 insertions, 2 deletions
diff --git a/Lib/ipaddress.py b/Lib/ipaddress.py
index 873c764..a3a04f7 100644
--- a/Lib/ipaddress.py
+++ b/Lib/ipaddress.py
@@ -1370,7 +1370,7 @@ 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__
@@ -2017,7 +2017,7 @@ 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 de77111..2eba740 100644
--- a/Lib/test/test_ipaddress.py
+++ b/Lib/test/test_ipaddress.py
@@ -2053,6 +2053,18 @@ 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).