https://github.com/EasyCrypt/easycrypt
Tip revision: a79f9aeb6de046ca12210d26317fab59c175d0dd authored by Pierre-Yves Strub on 08 July 2014, 09:43:21 UTC
Fix bug w.r.t. _tools presence detection.
Fix bug w.r.t. _tools presence detection.
Tip revision: a79f9ae
SecureChannels.ec
(* --------------------------------------------------------------------
* Copyright IMDEA Software Institute / INRIA - 2013, 2014
* -------------------------------------------------------------------- *)
require import Bool.
require import Int.
require import Option.
require import FSet.
type key.
type message.
type container.
module type Scheme = {
proc init(): unit
proc kg(): key
proc send(k:key,m:message): container
proc recv(k:key,c:container): message option
}.
theory MultiUser.
require import Array.
const users:int.
axiom users_pos: 0 < users.
module type Oracles = {
proc send(i:int,m0:message,m1:message): container option
proc recv(i:int,c:container): message option
}.
module Wrap(S:Scheme) = {
var qs:message set
var ks:key array
var b:bool
var auth:bool
proc initKeys(): unit = {
var i:int;
i = 0;
while (i < users)
{
ks.[i] = S.kg();
i = i + 1;
}
}
proc init(): unit = {
qs = FSet.empty;
auth = false;
S.init();
b = ${0,1};
initKeys();
}
proc send(i:int,m0:message,m1:message): container option = {
var r:container option;
var c:container;
if (0 <= i < users)
{
qs = add m0 (add m1 qs);
c = S.send(ks.[i],b ? m1 : m0);
r = Some c;
}
else
r = None;
return r;
}
proc recv(i:int,c:container): message option = {
var r:message option;
if (0 <= i < users)
{
r = S.recv(ks.[i],c);
if (r <> None /\ !mem (oget r) qs)
auth = true;
}
else
r = None;
return r;
}
proc guess(b':bool): bool = {
return b' = b;
}
proc auth(): bool = {
return auth;
}
}.
module type Adv_LOR(O:Oracles) = {
proc guess(): bool
}.
module LOR(S:Scheme,A:Adv_LOR) = {
module O = Wrap(S)
module A = A(O)
proc main(): bool = {
var b',sec,auth:bool;
O.init();
b' = A.guess();
sec = O.guess(b');
auth = O.auth();
return sec \/ auth;
}
}.
end MultiUser.
(* Reduce multi-user to single-user *)