58 lines
1.5 KiB
Plaintext
58 lines
1.5 KiB
Plaintext
# Lowe modified BAN concrete Andrew Secure RPC
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#
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# Modelled after the description in the SPORE library
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# http://www.lsv.ens-cachan.fr/spore/andrewLowe.html
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#
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# Note:
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# The shared key between I and R is modelled as k(I,R) currently
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# there is no way to express that this key is equal to k(R,I)
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# So it is possile that certain attacks that use this property are not found
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#
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# Note:
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# Recv 4 by the Initatior has been placed after the synchronisation claim
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# as it allows trivial synchronisation attacks otherwise (the message is
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# completely fresh and can therefore always be replaced by an arbitrary value
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# created by the intruder) which are not considered in SPORE
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#
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# Note:
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# According to SPORE there are no known attacks on this protocol
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#
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usertype SessionKey;
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const Fresh: Function;
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const Compromised: Function;
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protocol andrew-LoweBan(I,R)
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{
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role I
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{
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fresh ni: Nonce;
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var nr: Nonce;
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var kir: SessionKey;
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send_1(I,R, I,ni );
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recv_2(R,I, {ni,kir,R}k(I,R) );
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send_3(I,R, {ni}kir );
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claim_I1(I,Nisynch);
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claim_I2(I,Secret, kir);
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claim_I3(I,Empty, (Fresh,kir));
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recv_4(R,I, nr );
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}
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role R
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{
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var ni: Nonce;
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fresh nr: Nonce;
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fresh kir: SessionKey;
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recv_1(I,R, I,ni );
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send_2(R,I, {ni,kir,R}k(I,R) );
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recv_3(I,R, {ni}kir );
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send_4(R,I, nr );
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claim_R1(R,Nisynch);
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claim_R2(R,Secret, kir);
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claim_R3(R,Empty, (Fresh,kir));
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}
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}
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