82 lines
1.7 KiB
C++
82 lines
1.7 KiB
C++
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/** HEADDOC
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* @protocol SKEME
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* @reference Krawczyk, H., SKEME: A Versatile Secure Key Exchange Mechanism
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* for Internet,
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* Boyd C. and Mathuria A., Protocols for Authentication and
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* Key Agreement
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* @description SKEME is a set of protocols suitable for negotiation of
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* services in a general networked environment. The main
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* characteristics are forward secrecy, privacy and anonymity,
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* and DoS protection.
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* @variant Basic mode with pre-shared keys and correct application of DH
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**/
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/** MACRO DEFINITIONS
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* Needs preprocessing by cpp before fed to scyther
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**/
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#define __SKEME__
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#ifndef __ORACLE__
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#include "common.h"
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#endif
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/**
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* This role serves as an "oracle" to ensure the executability of the
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* protocol by taking care of the problems that arise from our way of
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* modelling k(I,R) = k(R,I).
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*/
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protocol @executability(O) {
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#define Gi g(i)
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#define Gr g(r)
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role O {
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var i, r: Nonce;
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var I, R: Agent;
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// msg 2
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recv_!O1( O, O, prf(k(R,I), Gi, g(r), R, I) );
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send_!O2( O, O, prf(k(I,R), Gi, g(r), R, I) );
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// msg 3
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recv_!O3( O, O, prf(k(I,R), Gr, g(i), I, R) );
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send_!O4( O, O, prf(k(R,I), Gr, g(i), I, R) );
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}
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#undef Gi
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#undef Gr
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}
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protocol skeme-psk(I, R)
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{
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role I {
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fresh i: Nonce;
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var Gr: Ticket;
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send_1( I, R, g(i) );
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recv_!2( R, I, Gr, prf(k(I,R), g(i), Gr, R, I) );
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send_!3( I, R, prf(k(I,R), Gr, g(i), I, R) );
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/* SECURITY CLAIMS */
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claim( I, SKR, SKi );
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claim( I, Alive );
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claim( I, Weakagree );
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}
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role R {
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fresh r: Nonce;
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var Gi: Ticket;
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recv_1( I, R, Gi );
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send_!2( R, I, g(r), prf(k(R,I), Gi, g(r), R, I) );
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recv_!3( I, R, prf(k(R,I), g(r), Gi, I, R) );
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/* SECURITY CLAIMS */
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claim( R, SKR, SKr );
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claim( R, Alive );
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claim( R, Weakagree );
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}
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}
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