84 lines
1.6 KiB
Plaintext
84 lines
1.6 KiB
Plaintext
/*
|
|
* KSL from SPORE
|
|
*
|
|
* Messages 6-8 are intended for repeated authentication, and there are
|
|
* known attacks on this. However, we don't model that yet.
|
|
*
|
|
* Furthermore, it is interesting to experiment here with key
|
|
* compromise (of kab), when this is implemented in Scyther.
|
|
*/
|
|
|
|
usertype Server, SessionKey, GeneralizedTimestamp, Ticket, TicketKey;
|
|
secret k: Function;
|
|
|
|
const a, b, e: Agent;
|
|
const s: Server;
|
|
|
|
/* give the intruder something to work with */
|
|
|
|
const ne: Nonce;
|
|
const kee: SessionKey;
|
|
untrusted e;
|
|
compromised k(e,s);
|
|
|
|
protocol ksl(A,B,S)
|
|
{
|
|
role A
|
|
{
|
|
const Na, Ma: Nonce;
|
|
var Nc, Mb: Nonce;
|
|
var T: Ticket;
|
|
var Kab: SessionKey;
|
|
|
|
send_1(A,B, Na, A);
|
|
read_4(B,A, { Na,B,Kab }k(A,S), T, Nc, {Na}Kab );
|
|
send_5(A,B, { Nc }Kab );
|
|
|
|
send_6(A,B, Ma,T );
|
|
read_7(B,A, Mb,{Ma}Kab );
|
|
send_8(A,B, {Mb}Kab );
|
|
|
|
claim_A1(A,Secret, Kab);
|
|
claim_A2(A,Niagree);
|
|
claim_A3(A,Nisynch);
|
|
}
|
|
|
|
role B
|
|
{
|
|
var Na,Ma: Nonce;
|
|
const Nb,Nc,Mb: Nonce;
|
|
var Kab: SessionKey;
|
|
const Kbb: TicketKey;
|
|
const Tb: GeneralizedTimestamp;
|
|
var T: Ticket;
|
|
|
|
read_1(A,B, Na, A);
|
|
send_2(B,S, Na, A, Nb, B );
|
|
read_3(S,B, { Nb, A, Kab }k(B,S), T );
|
|
send_4(B,A, T, { Tb, A, Kab }Kbb, Nc, {Na}Kab );
|
|
read_5(A,B, { Nc }Kab );
|
|
|
|
read_6(A,B, Ma,{ Tb, A, Kab }Kbb );
|
|
send_7(B,A, Mb,{Ma}Kab );
|
|
read_8(A,B, {Mb}Kab );
|
|
|
|
claim_B1(B,Secret, Kab);
|
|
claim_B2(B,Niagree);
|
|
claim_B3(B,Nisynch);
|
|
}
|
|
|
|
role S
|
|
{
|
|
var Na, Nb: Nonce;
|
|
const Kab: SessionKey;
|
|
|
|
read_2(B,S, Na, A, Nb, B );
|
|
send_3(S,B, { Nb, A, Kab }k(B,S), { Na,B,Kab }k(A,S) );
|
|
}
|
|
}
|
|
|
|
run ksl.A(a,b,s);
|
|
run ksl.B(a,b,s);
|
|
run ksl.S(a,b,s);
|
|
|