Revert "dns: fix off-by-four in EDNS0 OWNER Option (secdev#4955)"

This reverts commit 2b220b9.

Author: evverx

scapy/layers/dns.py

@@ -494,11 +494,11 @@ class EDNS0OWN(_EDNS0Dummy):
                    MACField("primary_mac", "00:00:00:00:00:00"),
                    ConditionalField(
                        MACField("wakeup_mac", "00:00:00:00:00:00"),
-                       lambda pkt: (pkt.optlen or 0) >= 14),
+                       lambda pkt: (pkt.optlen or 0) >= 18),
                    ConditionalField(
                        StrLenField("password", "",
-                                   length_from=lambda pkt: pkt.optlen - 14),
-                       lambda pkt: (pkt.optlen or 0) >= 18)]
+                                   length_from=lambda pkt: pkt.optlen - 18),
+                       lambda pkt: (pkt.optlen or 0) >= 22)]
 
     def post_build(self, pkt, pay):
         pkt += pay

test/scapy/layers/dns_edns0.uts

@@ -212,32 +212,3 @@ for opt_class in EDNS0OPT_DISPATCHER.values():
     p = DNSRROPT(raw(DNSRROPT(rdata=[EDNS0TLV(), opt_class(), opt_class()])))
     assert len(p.rdata) == 3
     assert all(Raw not in opt for opt in p.rdata)
-
-
-+ EDNS0 - Owner
-
-= Dissection
-
-p = EDNS0OWN(b'\x00\x04\x00\x08\x00\x9b\x11"3DUf')
-assert p.optcode == 4
-assert p.optlen == 8
-assert p.v == 0
-assert p.s == 155
-assert p.primary_mac == '11:22:33:44:55:66'
-
-p = EDNS0OWN(b'\x00\x04\x00\x0e\x00\x9b\x11"3DUffUD3"\x11')
-assert p.optcode == 4
-assert p.optlen == 14
-assert p.v == 0
-assert p.s == 155
-assert p.primary_mac == '11:22:33:44:55:66'
-assert p.wakeup_mac == '66:55:44:33:22:11'
-
-p = EDNS0OWN(b'\x00\x04\x00\x12\x00\x9b\x11"3DUffUD3"\x11abcd')
-assert p.optcode == 4
-assert p.optlen == 18
-assert p.v == 0
-assert p.s == 155
-assert p.primary_mac == '11:22:33:44:55:66'
-assert p.wakeup_mac == '66:55:44:33:22:11'
-assert p.password == b'abcd'