63 lines
1.4 KiB
Plaintext
63 lines
1.4 KiB
Plaintext
# CCITT X.509 (3)
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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/ccittx509_3.html
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#
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# Note:
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# The protocol description also states that Xa and Ya should be fresh
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# this can not be verified using scyther
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#
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const pk: Function;
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secret sk: Function;
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inversekeys(pk,sk);
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usertype Timestamp;
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protocol ccitt5093(I,R)
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{
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role I
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{
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const Ta: Timestamp;
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var Tb: Timestamp;
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const Na,Xa,Ya: Nonce;
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var Xb,Nb,Yb: Nonce;
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send_1(I,R, I,{Ta, Na, R, Xa,{Ya}pk(R)}sk(I));
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read_2(R,I, R,{Tb, Nb, I, Na, Xb,{Yb}pk(I)}sk(R));
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send_3(I,R, I, {Nb}sk(I));
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claim_4(I,Nisynch);
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}
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role R
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{
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var Ta: Timestamp;
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const Tb: Timestamp;
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var Na,Xa,Ya: Nonce;
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const Xb,Yb,Nb: Nonce;
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read_1(I,R, I,{Ta, Na, R, Xa,{Ya}pk(R)}sk(I));
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send_2(R,I, R,{Tb, Nb, I, Na, Xb,{Yb}pk(I)}sk(R));
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read_3(I,R, I, {Nb}sk(I));
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claim_5(R,Nisynch);
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# There should also be Fresh Xa and Fresh Ya claims here
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}
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}
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const Alice,Bob,Eve: Agent;
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untrusted Eve;
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const ne: Nonce;
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const te: Timestamp;
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compromised sk(Eve);
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# This scenario should find the attack described in SPORE
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# run ccitt5093.I(Alice,Bob);
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# run ccitt5093.I(Alice,Eve);
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# run ccitt5093.R(Alice,Bob);
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# General scenario, 2 parallel runs of the protocol
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run ccitt5093.I(Agent,Agent);
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run ccitt5093.R(Agent,Agent);
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run ccitt5093.I(Agent,Agent);
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run ccitt5093.R(Agent,Agent);
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