98 lines
4.0 KiB
Plaintext
98 lines
4.0 KiB
Plaintext
(*****************************************************************************
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* Copyright (c) 2005-2010 ETH Zurich, Switzerland
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* 2008-2015 Achim D. Brucker, Germany
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* 2009-2016 Université Paris-Sud, France
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* 2015-2016 The University of Sheffield, UK
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*
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are
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* met:
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*
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* * Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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*
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* * Redistributions in binary form must reproduce the above
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* copyright notice, this list of conditions and the following
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* disclaimer in the documentation and/or other materials provided
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* with the distribution.
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*
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* * Neither the name of the copyright holders nor the names of its
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* contributors may be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*****************************************************************************)
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subsection \<open>Personal Firewall: Datatype\<close>
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theory
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PersonalFirewallDatatype
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imports
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"../../UPF-Firewall"
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begin
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text\<open>
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The most basic firewall scenario; there is a personal PC on one side and the Internet on the
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other. There are two policies: the first one allows all traffic from the PC to the Internet and
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denies all coming into the PC. The second policy only allows specific ports from the PC. This
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scenario comes in three variants: the first one specifies the allowed protocols directly, the
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second together with their respective port numbers, the third one only with the port numbers.
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\<close>
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datatype Adr = pc | internet
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type_synonym DatatypeTwoNets = "Adr \<times> int"
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instance Adr::adr ..
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definition
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PC :: "DatatypeTwoNets net" where
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"PC = {{(a,b). a = pc}}"
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definition
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Internet :: "DatatypeTwoNets net" where
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"Internet = {{(a,b). a = internet}}"
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definition
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not_in_same_net :: "(DatatypeTwoNets,DummyContent) packet \<Rightarrow> bool" where
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"not_in_same_net x = ((src x \<sqsubset> PC \<longrightarrow> dest x \<sqsubset> Internet) \<and> (src x \<sqsubset> Internet \<longrightarrow> dest x \<sqsubset> PC))"
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text \<open>
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Definitions of the policies
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In fact, the short definitions wouldn't have to be written down - they
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are the automatically simplified versions of their big counterparts.
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\<close>
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definition
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strictPolicy :: "(DatatypeTwoNets,DummyContent) FWPolicy" where
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"strictPolicy = deny_all ++ allow_all_from_to PC Internet"
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definition
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PortPolicy :: "(DatatypeTwoNets,'b) FWPolicy" where
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"PortPolicy = deny_all ++ allow_from_ports_to {80::port,24,21} PC Internet"
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definition
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PortPolicyBig :: "(DatatypeTwoNets,'b) FWPolicy" where
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"PortPolicyBig =
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allow_from_port_to (80::port) PC Internet \<Oplus>
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allow_from_port_to (24::port) PC Internet \<Oplus>
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allow_from_port_to (21::port) PC Internet \<Oplus>
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deny_all"
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lemmas policyLemmas = strictPolicy_def PortPolicy_def PC_def Internet_def PortPolicyBig_def src_def
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PolicyCombinators PortCombinators in_subnet_def
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end
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