Merge branch 'main' of https://github.com/digital-phoenix/rosenpass into main

* 'main' of https://github.com/digital-phoenix/rosenpass:
  fix: fix Rust code in markdown files
  feat: add format_rustcode.sh script
  fix: add deprecated keygen command

analysis/03_identity_hiding.entry.mpv

@@ -0,0 +1,121 @@
+/*
+  This identity hiding process tests whether the rosenpass protocol is able to protect the identity of an initiator or responder.
+  The participants in the test are trusted initiators, trusted responders and compromised initiators and responders.
+  The test consists of two phases. In the first phase all of the participants can communicate with each other using the rosenpass protocol.
+  An attacker observes the first phase and is able to intercept and modify messages and choose participants to communicate with each other
+
+  In the second phase if the anonymity of an initiator is being tested then one of two trusted initiators is chosen.
+  The chosen initiator communicates directly with a trusted responder.
+  If an attacker can determine which initiator was chosen then the anonymity of the initiator has been compromised.
+  Otherwise the protocol has successfully protected the initiators’ identity.
+
+  If the anonymity of a responder is being tested then one of two trusted responders is chosen instead.
+  Then an initiator communicates directly with the chosen responder.
+  If an attacker can determine which responder was chosen then the anonymity of the responder is compromised.
+  Otherwise the protocol successfully protects the identity of a responder.
+
+  The Proverif code treats the public key as synonymous with identity.
+  In the above test when a responder or initiator is chosen what is actually chosen is the public/private key pair to use for communication.
+  Traditionally when a responder or initiator is chosen they would be chosen randomly.
+  The way Proverif makes a "choice" is by simulating multiple processes, one process per choice
+  Then the processes are compared and if an association between a public key and a process can be made the test fails.
+  As the choice is at least as bad as choosing the worst possible option the credibility of the test is maintained.
+  The drawback is that Proverif is only able to tell if the identity can be brute forced but misses any probabilistic associations.
+  As usual Proverif also assumes perfect encryption and in particular assumes encryption cannot be linked to identity.
+
+  One of the tradeoffs made here is that the choice function in Proverif is slow but this is in favour of being able to write more precise tests.
+  Another issue is the choice function does not work with queries so a test needs to be run for each set of assumptions.
+  In this case the test uses secure rng and a fresh secure biscuit key.
+*/
+
+
+#include "config.mpv"
+
+#define CHAINING_KEY_EVENTS 1
+#define MESSAGE_TRANSMISSION_EVENTS 1
+#define SESSION_START_EVENTS 0
+#define RANDOMIZED_CALL_IDS 0
+#undef FULL_MODEL
+#undef SIMPLE_MODEL
+#define SIMPLE_MODEL 1
+
+#include "prelude/basic.mpv"
+#include "crypto/key.mpv"
+#include "rosenpass/oracles.mpv"
+#include "crypto/kem.mpv"
+
+#define INITIATOR_TEST
+#define NEW_TRUSTED_SEED(name)            \
+  new MCAT(name, _secret_seed):seed_prec; \
+  name <- make_trusted_seed(MCAT(name, _secret_seed)); \
+
+free D:channel [private].
+free secure_biscuit_no:Atom [private].
+free secure_sidi,secure_sidr:SessionId [private].
+free secure_psk:key [private].
+free initiator1, initiator2:kem_sk_prec.
+free responder1, responder2:kem_sk_prec.
+
+let secure_init_hello(initiator: kem_sk_tmpl, sidi : SessionId, psk: key_tmpl, responder: kem_sk_tmpl) =
+  NEW_TRUSTED_SEED(seski_trusted_seed)
+  NEW_TRUSTED_SEED(ssptr_trusted_seed)
+  Oinitiator_inner(sidi, initiator, psk, responder, seski_trusted_seed, ssptr_trusted_seed, D).
+
+let secure_resp_hello(initiator: kem_sk_tmpl, responder: kem_sk_tmpl, sidr:SessionId, sidi:SessionId, biscuit_no:Atom, psk:key_tmpl) =
+  in(D, Envelope(k, IH2b(InitHello(=sidi, epki, sctr, pidiC, auth))));
+  ih <- InitHello(sidi, epki, sctr, pidiC, auth);
+  NEW_TRUSTED_SEED(septi_trusted_seed)
+  NEW_TRUSTED_SEED(sspti_trusted_seed)
+  Oinit_hello_inner(sidr, biscuit_no, responder, psk, initiator, septi_trusted_seed, sspti_trusted_seed, ih, D).
+
+let secure_init_conf(initiator: kem_sk_tmpl, responder: kem_sk_tmpl, psk:key_tmpl, sidi:SessionId, sidr:SessionId) =
+  in(D, Envelope(k3, IC2b(InitConf(=sidi, =sidr, biscuit, auth3))));
+  ic <- InitConf(sidi,sidr,biscuit, auth3);
+  NEW_TRUSTED_SEED(seski_trusted_seed)
+  NEW_TRUSTED_SEED(ssptr_trusted_seed)
+  Oinit_conf_inner(initiator, psk, responder, ic).
+
+let secure_communication(initiator: kem_sk_tmpl, responder:kem_sk_tmpl) =
+  secure_key <- prepare_key(secure_psk);
+  (!secure_init_hello(initiator, secure_sidi, secure_key, responder))
+  | !secure_resp_hello(initiator, responder, secure_sidr, secure_sidi, secure_biscuit_no, secure_key)
+  | !(secure_init_conf(initiator, responder, secure_key, secure_sidi, secure_sidr)).
+
+let pipeChannel(D:channel, C:channel) =
+  in(D, b:bits);
+  out(C, b).
+
+fun kem_private(kem_pk): kem_sk
+  reduc forall sk_tmpl:kem_sk;
+    kem_private(kem_pub(sk_tmpl)) = sk_tmpl[private].
+
+let secretCommunication() =
+#ifdef INITIATOR_TEST
+  initiator_pk <- choice[setup_kem_pk(make_trusted_kem_sk(initiator1)), setup_kem_pk(make_trusted_kem_sk(initiator2))];
+  initiator_seed <- prepare_kem_sk(kem_private(initiator_pk)); 
+#else
+  initiator_seed <- prepare_kem_sk(trusted_kem_sk(initiator1));
+#endif
+#ifdef RESPONDER_TEST
+  responder_pk <- choice[setup_kem_pk(make_trusted_kem_sk(responder1)), setup_kem_pk(make_trusted_kem_sk(responder2))];
+  responder_seed <- prepare_kem_sk(kem_private(responder_pk));
+#else
+  responder_seed <- prepare_kem_sk(trusted_kem_sk(responder1));
+#endif
+  secure_communication(initiator_seed, responder_seed) | !pipeChannel(D, C).
+
+let reveal_pks() =
+  out(C, setup_kem_pk(make_trusted_kem_sk(responder1)));
+  out(C, setup_kem_pk(make_trusted_kem_sk(responder2)));
+  out(C, setup_kem_pk(make_trusted_kem_sk(initiator1)));
+  out(C, setup_kem_pk(make_trusted_kem_sk(initiator2))).
+
+let rosenpass_main2() = 
+  REP(INITIATOR_BOUND, Oinitiator)
+  | REP(RESPONDER_BOUND, Oinit_hello)
+  | REP(RESPONDER_BOUND, Oinit_conf).
+
+let identity_hiding_main() = 
+  0 | reveal_pks() |  rosenpass_main2() | phase 1; secretCommunication().
+
+let main = identity_hiding_main.

analysis/rosenpass/oracles.mpv

@@ -47,14 +47,16 @@ CK_EV(  event OskOinit_conf(key, key). )
 MTX_EV( event ICRjct(InitConf_t, key, kem_sk, kem_pk). )
 SES_EV( event ResponderSession(InitConf_t, key). )
 event ConsumeBiscuit(Atom, kem_sk, kem_pk, Atom).
-let Oinit_conf() = 
-  in(C, Cinit_conf(Ssskm, Spsk, Sspkt, ic));
+
+let Oinit_conf_inner(Ssskm:kem_sk_tmpl, Spsk:key_tmpl, Sspkt:kem_sk_tmpl, ic:InitConf_t) =
 #if RANDOMIZED_CALL_IDS
   new call:Atom;
 #else
   call <- Cinit_conf(Ssskm, Spsk, Sspkt, ic);
 #endif
+
   SETUP_HANDSHAKE_STATE()
+
   eski <- kem_sk0;
   epki <- kem_pk0;
   let try_ = (
@@ -72,6 +74,10 @@ let Oinit_conf() =
     0
 #endif
   ).
+  
+let Oinit_conf() = 
+  in(C, Cinit_conf(Ssskm, Spsk, Sspkt, ic));
+  Oinit_conf_inner(Ssskm, Spsk, Sspkt, ic).
 
 restriction biscuit_no:Atom, sskm:kem_sk, spkr:kem_pk, ad1:Atom, ad2:Atom;
   event(ConsumeBiscuit(biscuit_no, sskm, spkr, ad1)) && event(ConsumeBiscuit(biscuit_no, sskm, spkr, ad2))
@@ -85,8 +91,8 @@ CK_EV(  event OskOresp_hello(key, key, key). )
 MTX_EV( event RHRjct(RespHello_t, key, kem_sk, kem_pk). )
 MTX_EV( event ICSent(RespHello_t, InitConf_t, key, kem_sk, kem_pk). )
 SES_EV( event InitiatorSession(RespHello_t, key). )
-let Oresp_hello(HS_DECL_ARGS) =
-  in(C, Cresp_hello(RespHello(sidr, =sidi, ecti, scti, biscuit, auth)));
+let Oresp_hello(HS_DECL_ARGS, C_in:channel) =
+  in(C_in, Cresp_hello(RespHello(sidr, =sidi, ecti, scti, biscuit, auth)));
   rh <- RespHello(sidr, sidi, ecti, scti, biscuit, auth);
   /* try */ let ic = (
     ck_ini <- ck;
@@ -98,7 +104,7 @@ let Oresp_hello(HS_DECL_ARGS) =
     SES_EV( event InitiatorSession(rh, osk); )
     ic
   /* success */ ) in (
-    out(C, ic)
+    out(C_in, Envelope(create_mac(spkt, IC2b(ic)), IC2b(ic)))
   /* fail */ ) else (
 #if MESSAGE_TRANSMISSION_EVENTS
     event RHRjct(rh, psk, sski, spkr)
@@ -116,8 +122,8 @@ MTX_EV( event IHRjct(InitHello_t, key, kem_sk, kem_pk). )
 MTX_EV( event RHSent(InitHello_t, RespHello_t, key, kem_sk, kem_pk). )
 event ConsumeSidr(SessionId, Atom).
 event ConsumeBn(Atom, kem_sk, kem_pk, Atom).
-let Oinit_hello() = 
-  in(C, Cinit_hello(sidr, biscuit_no, Ssskm, Spsk, Sspkt, Septi, Sspti, ih));
+
+let Oinit_hello_inner(sidm:SessionId, biscuit_no:Atom, Ssskm:kem_sk_tmpl, Spsk:key_tmpl, Sspkt: kem_sk_tmpl, Septi: seed_tmpl, Sspti: seed_tmpl, ih: InitHello_t, C_out:channel) = 
 #if RANDOMIZED_CALL_IDS
   new call:Atom;
 #else
@@ -125,14 +131,19 @@ let Oinit_hello() =
 #endif
   // TODO: This is ugly
   let InitHello(sidi, epki, sctr, pidiC, auth) = ih in
+
   SETUP_HANDSHAKE_STATE()
+
   eski <- kem_sk0;
-  epti <- rng_key(setup_seed(Septi)); // RHR4
-  spti <- rng_key(setup_seed(Sspti)); // RHR5
+
   event ConsumeBn(biscuit_no, sskm, spkt, call);
   event ConsumeSidr(sidr, call);
+
+  epti <- rng_key(setup_seed(Septi)); // RHR4
+  spti <- rng_key(setup_seed(Sspti)); // RHR5
   event ConsumeSeed(Epti, setup_seed(Septi), call);
   event ConsumeSeed(Spti, setup_seed(Sspti), call);
+
   let rh = (
     INITHELLO_CONSUME()
     ck_ini <- ck;
@@ -141,7 +152,8 @@ let Oinit_hello() =
     MTX_EV( event RHSent(ih, rh, psk, sskr, spki); )
     rh
   /* success */ ) in (
-    out(C, rh)
+    out(C_out, Envelope(create_mac(spkt, RH2b(rh)), RH2b(rh)))
+
   /* fail */ ) else (
 #if MESSAGE_TRANSMISSION_EVENTS
     event IHRjct(ih, psk, sskr, spki)
@@ -150,6 +162,10 @@ let Oinit_hello() =
 #endif
   ).
 
+let Oinit_hello() = 
+  in(C, Cinit_hello(sidr, biscuit_no, Ssskm, Spsk, Sspkt, Septi, Sspti, ih));
+  Oinit_hello_inner(sidr, biscuit_no, Ssskm, Spsk, Sspkt, Septi, Sspti, ih, C).
+
 restriction sid:SessionId, ad1:Atom, ad2:Atom;
   event(ConsumeSidr(sid, ad1)) && event(ConsumeSidr(sid, ad2))
     ==> ad1 = ad2.
@@ -167,26 +183,34 @@ CK_EV( event OskOinitiator_ck(key). )
 CK_EV( event OskOinitiator(key, key, kem_sk, kem_pk, key). )
 MTX_EV( event IHSent(InitHello_t, key, kem_sk, kem_pk). )
 event ConsumeSidi(SessionId, Atom).
+
+let Oinitiator_inner(sidi: SessionId, Ssskm: kem_sk_tmpl, Spsk: key_tmpl, Sspkt: kem_sk_tmpl, Seski: seed_tmpl, Ssptr: seed_tmpl, C_out:channel) =
+  #if RANDOMIZED_CALL_IDS
+    new call:Atom;
+  #else
+    call <- Cinitiator(sidi, Ssskm, Spsk, Sspkt, Seski, Ssptr);
+  #endif
+
+    SETUP_HANDSHAKE_STATE()
+
+    sidr <- sid0;
+
+    RNG_KEM_PAIR(eski, epki, Seski) // IHI3
+    sptr <- rng_key(setup_seed(Ssptr)); // IHI5
+    event ConsumeSidi(sidi, call);
+    event ConsumeSeed(Sptr, setup_seed(Ssptr), call);
+    event ConsumeSeed(Eski, setup_seed(Seski), call);
+
+    INITHELLO_PRODUCE()
+    CK_EV( event OskOinitiator_ck(ck); ) 
+    CK_EV( event OskOinitiator(ck, psk, sski, spkr, sptr); )
+    MTX_EV( event IHSent(ih, psk, sski, spkr); )
+    out(C_out, Envelope(create_mac(spkt, IH2b(ih)), IH2b(ih)));
+    Oresp_hello(HS_PASS_ARGS, C_out).
+
 let Oinitiator() =
   in(C, Cinitiator(sidi, Ssskm, Spsk, Sspkt, Seski, Ssptr));
-#if RANDOMIZED_CALL_IDS
-  new call:Atom;
-#else
-  call <- Cinitiator(sidi, Ssskm, Spsk, Sspkt, Seski, Ssptr);
-#endif
-  SETUP_HANDSHAKE_STATE()
-  RNG_KEM_PAIR(eski, epki, Seski) // IHI3
-  sidr <- sid0;
-  sptr <- rng_key(setup_seed(Ssptr)); // IHI5
-  event ConsumeSidi(sidi, call);
-  event ConsumeSeed(Sptr, setup_seed(Ssptr), call);
-  event ConsumeSeed(Eski, setup_seed(Seski), call);
-  INITHELLO_PRODUCE()
-  CK_EV( event OskOinitiator_ck(ck); ) 
-  CK_EV( event OskOinitiator(ck, psk, sski, spkr, sptr); )
-  MTX_EV( event IHSent(ih, psk, sski, spkr); )
-  out(C, ih);
-  Oresp_hello(HS_PASS_ARGS).
+  Oinitiator_inner(sidi, Ssskm, Spsk, Sspkt, Seski, Ssptr, C).
 
 restriction sid:SessionId, ad1:Atom, ad2:Atom;
   event(ConsumeSidi(sid, ad1)) && event(ConsumeSidi(sid, ad2))

analysis/rosenpass/protocol.mpv

@@ -2,6 +2,12 @@
 #include "crypto/kem.mpv"
 #include "rosenpass/handshake_state.mpv"
 
+fun Envelope(
+  key,
+  bits
+): bits [data].
+letfun create_mac(pk:kem_pk, payload:bits) = lprf2(MAC, kem_pk2b(pk), payload).
+
 type InitHello_t.
 fun InitHello(
   SessionId, // sidi
@@ -11,6 +17,8 @@ fun InitHello(
   bits       // auth
 ) : InitHello_t [data].
 
+fun IH2b(InitHello_t) : bitstring [typeConverter].
+
 #define INITHELLO_PRODUCE()       \
   ck <- lprf1(CK_INIT, kem_pk2b(spkr)); /* IHI1 */ \
   /* not handled here */                /* IHI2 */ \
@@ -41,7 +49,9 @@ fun RespHello(
     bits       // auth
 ) : RespHello_t [data].
 
-#define RESPHELLO_PRODUCE()                   \
+fun RH2b(RespHello_t) : bitstring [typeConverter].
+
+#define RESPHELLO_PRODUCE()  \
   /* not handled here */           /* RHR1 */ \
   MIX2(sid2b(sidr), sid2b(sidi))   /* RHR3 */ \
   ENCAPS_AND_MIX(ecti, epki, epti) /* RHR4 */ \
@@ -67,6 +77,8 @@ fun InitConf(
     bits       // auth
 ) : InitConf_t [data].
 
+fun IC2b(InitConf_t) : bitstring [typeConverter].
+
 #define INITCONF_PRODUCE()                  \
   MIX2(sid2b(sidi), sid2b(sidr)) /* ICI3 */ \
   ENCRYPT_AND_MIX(auth, empty)   /* ICI4 */ \