scyther/spdl/misc/yahalom-ban.spdl

58 lines
886 B
Plaintext

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