52 lines
720 B
Plaintext
52 lines
720 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
|
|
{
|
|
fresh na;
|
|
var nb;
|
|
var ticket;
|
|
var kab;
|
|
|
|
send_1(A,B, A,na);
|
|
recv_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
|
|
{
|
|
fresh nb;
|
|
var na;
|
|
var ticket;
|
|
var kab;
|
|
|
|
recv_1(A,B, A,na);
|
|
send_2(B,S, B,nb, {A,na}k(B,S) );
|
|
recv_4(A,B, {A,kab,nb}k(B,S) , {nb}kab );
|
|
claim_6(B, Secret,kab);
|
|
}
|
|
|
|
role S
|
|
{
|
|
fresh kab;
|
|
var na,nb;
|
|
|
|
recv_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) );
|
|
}
|
|
}
|
|
|