80 lines
1.2 KiB
Plaintext
80 lines
1.2 KiB
Plaintext
/*
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* Needham-Schroeder symmetric
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* Amended version (from Sjouke's interpret.)
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*/
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/* symmetric */
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usertype SessionKey;
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secret k: Function;
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/* agents */
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const a,b,e: Agent;
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/* untrusted e */
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untrusted e;
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const ne: Nonce;
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const kee: SessionKey;
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compromised k(e,e);
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compromised k(e,a);
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compromised k(e,b);
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compromised k(a,e);
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compromised k(b,e);
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/* {}x used for public (invertible) function modeling */
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usertype PseudoFunction;
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const succ: PseudoFunction;
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usertype Ticket;
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protocol nssymmetric(A,S,B)
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{
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role A
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{
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const na: Nonce;
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var T1: Ticket;
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var T2: Ticket;
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var kab: SessionKey;
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var nb: Nonce;
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send_1(A,B, A );
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read_2(B,A, T1 );
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send_3(A,S, A,B,na,T1 );
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read_4(S,A, { na,B,kab,T2 }k(A,S) );
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send_5(A,B, T2 );
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read_6(B,A, { nb }kab );
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send_7(A,B, { {nb}succ }kab );
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claim_8(A, Secret, kab);
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}
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role S
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{
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const kab: SessionKey;
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var na: Nonce;
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var nb: Nonce;
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read_3(A,S, A,B,na, { A,nb }k(B,S) );
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send_4(S,A, { na,B,kab, { kab,A }k(B,S) }k(A,S) );
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}
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role B
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{
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var kab: SessionKey;
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const nb: Nonce;
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read_1(A,B, A );
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send_2(B,A, { A,nb }k(B,S) );
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read_5(A,B, { kab,A }k(B,S) );
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send_6(B,A, { nb }kab );
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read_7(A,B, { {nb}succ }kab );
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claim_9(B, Secret, kab);
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}
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}
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