# TMN
#
# Modelled after the description in the SPORE library
# http://www.lsv.ens-cachan.fr/spore/tmn.html
#
# Note:
# According to Boyd and Mathuria Kb is the session key this is not clear
# from the description in SPORE
usertype SessionKey;

const Fresh: Function;
const Compromised: Function;

protocol tmn(I,R,S)
{
    role I
    {
        fresh Ki: SessionKey;
        var Kr: SessionKey;

        send_1(I,S, R,{Ki}pk(S) );
        read_4(S,I, R,{Kr}Ki );

        claim_I1(I,Secret,Kr);
        claim_I2(I,Nisynch);
        claim_I3(I,Empty,(Fresh,Kr));
    }    
    
    role R
    {
        fresh Kr: SessionKey;

        read_2(S,R, I );
        send_3(R,S, I, { Kr }pk(S) );

        claim_R1(R,Secret,Kr);
        claim_R2(R,Nisynch);
        claim_R3(R,Empty,(Fresh,Kr));
    }

    role S
    {
        var Ki,Kr: SessionKey;

        read_1(I,S, R,{Ki}pk(S) );
        send_2(S,R, I );
        read_3(R,S, I, { Kr }pk(S) );
        send_4(S,I, R,{Kr}Ki );
    }
}