76 lines
1.8 KiB
Plaintext
76 lines
1.8 KiB
Plaintext
# BAN concrete Andrew Secure RPC
|
|
#
|
|
# Modelled after the description in the SPORE library
|
|
# http://www.lsv.ens-cachan.fr/spore/andrewBAN2.html
|
|
#
|
|
# Note:
|
|
# The shared key between I and R is modelled as k(I,R) currently
|
|
# there is no way to express that this key is equal to k(R,I)
|
|
# In order to overcome this a 'dummy' role X has been hadded that recrypts
|
|
# a given term crypted with k(I,R) with k(R,I)
|
|
#
|
|
# Note:
|
|
# Read 4 by the Initatior has been placed after the synchronisation claim
|
|
# as it allows trivial synchronisation attacks otherwise (the message is
|
|
# completely fresh and can therefore always be replaced by an arbitrary value
|
|
# created by the intruder) which are not considered in SPORE
|
|
#
|
|
|
|
usertype SessionKey;
|
|
secret k: Function;
|
|
const Fresh: Function;
|
|
const Compromised: Function;
|
|
|
|
protocol @swapkey(X)
|
|
{
|
|
# Protocol added to work around the symmetry problems where k(I,R) != k(R,I)
|
|
role X
|
|
{
|
|
var I,R: Agent;
|
|
var T:Ticket;
|
|
read_!X1(X,X,I,R,{T}k(I,R));
|
|
send_!X2(X,X,{T}k(R,I));
|
|
}
|
|
}
|
|
|
|
protocol andrew-Concrete(I,R)
|
|
{
|
|
|
|
role I
|
|
{
|
|
const ni: Nonce;
|
|
var nr: Nonce;
|
|
var kir: SessionKey;
|
|
|
|
send_1(I,R, I,ni );
|
|
read_2(R,I, {ni,kir}k(I,R) );
|
|
send_3(I,R, {ni}kir);
|
|
claim_I1(I,Secret,kir);
|
|
claim_I2(I,Nisynch);
|
|
claim_I3(I,Empty,(Fresh,kir));
|
|
read_6(R,I, nr);
|
|
}
|
|
|
|
role R
|
|
{
|
|
var ni: Nonce;
|
|
const nr: Nonce;
|
|
const kir: SessionKey;
|
|
|
|
read_1(I,R, I,ni );
|
|
send_2(R,I, {ni,kir}k(I,R) );
|
|
read_3(I,R, {ni}kir);
|
|
send_6(R,I, nr);
|
|
claim_R1(R,Secret,kir);
|
|
claim_R2(R,Nisynch);
|
|
claim_R3(R,Empty,(Fresh,kir));
|
|
}
|
|
}
|
|
|
|
const Alice,Bob,Eve: Agent;
|
|
|
|
untrusted Eve;
|
|
const ne: Nonce;
|
|
const kee: SessionKey;
|
|
|