52 lines
720 B
Plaintext
52 lines
720 B
Plaintext
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// BAN modified version of the yahalom protocol
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// Type flaw
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// This version actually works!
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usertype Server;
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const a,b,c : Agent;
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const s : Server;
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secret k : Function;
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protocol yahalomBan(A,B,S)
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{
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role A
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{
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const na;
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var nb;
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var ticket;
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var kab;
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send_1(A,B, A,na);
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read_3(S,A, nb, {B,kab,na}k(A,S), ticket );
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send_4(A,B, ticket, {nb}kab );
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claim_5(A, Secret,kab);
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}
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role B
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{
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const nb;
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var na;
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var ticket;
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var kab;
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read_1(A,B, A,na);
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send_2(B,S, B,nb, {A,na}k(B,S) );
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read_4(A,B, {A,kab,nb}k(B,S) , {nb}kab );
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claim_6(B, Secret,kab);
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}
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role S
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{
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const kab;
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var na,nb;
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read_2(B,S, B,nb, {A,na}k(B,S) );
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send_3(S,A, nb, {B,kab,na}k(A,S), {A,kab,nb}k(B,S) );
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}
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}
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