# 1 "fourway-HSDDM05.cpp"
# 1 "<built-in>"
# 1 "<command line>"
# 1 "fourway-HSDDM05.cpp"
# 10 "fourway-HSDDM05.cpp"
usertype Params, String;

const hash: Function;
secret unhash: Function;
inversekeys(hash,unhash);
secret pmk: Function;

const msg1,msg2,msg3,msg4: String;

const Alice, Bob, Eve: Agent;

protocol fourway(X,Y)
{
        role X
        {
                const x: Nonce;
                var y: Nonce;

                send_1( X,Y, x,msg1 );
                read_2( Y,X, y,msg2,hash( hash( pmk(X,Y),x,y ),y,msg2 ) );
                send_3( X,Y, x,msg3,hash( hash( pmk(X,Y),x,y ),x,msg3 ) );
                read_4( Y,X, msg4,hash( hash( pmk(X,Y),x,y ),msg4 ) );

                claim_X1( X, Secret, hash( pmk(X,Y),x,y ) );
                claim_X2( X, Niagree );
        }

        role Y
        {
                var x: Nonce;
                const y: Nonce;

                read_1( X,Y, x,msg1 );
                send_2( Y,X, y,msg2,hash( hash( pmk(X,Y),x,y ),y,msg2 ) );
                read_3( X,Y, x,msg3,hash( hash( pmk(X,Y),x,y ),x,msg3 ) );
                send_4( Y,X, msg4,hash( hash( pmk(X,Y),x,y ),msg4 ) );

                claim_Y1( Y, Secret, hash( pmk(X,Y),x,y ) );
                claim_Y2( Y, Niagree );
        }
}


untrusted Eve;
compromised pmk(Eve,Alice);
compromised pmk(Eve,Bob);
compromised pmk(Alice,Eve);
compromised pmk(Bob,Eve);