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- Big change in the Arachne algorithm: decryptor sequences now get

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expanded explicitly. This solves a long-standing issue with {k}k
  decryption to yield k. Needs some testing to ensure that it did not
  introduce any new errors.
This commit is contained in:
ccremers 2005-05-17 18:45:01 +00:00
parent 2110206d80
commit f22ce0dcb9
8 changed files with 581 additions and 325 deletions
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227
src/arachne.c
View File

@ -7,6 +7,7 @@
*
*/
#include <stdlib.h>
#include <limits.h>
#include <float.h>
#ifdef DEBUG
@ -48,6 +49,7 @@ static int attack_length;
Protocol INTRUDER; // Pointers, to be set by the Init
Role I_M; // Same here.
Role I_RRS;
Role I_RRSD;
static int indentDepth;
static int proofDepth;
@ -125,6 +127,15 @@ arachneInit (const System mysys)
add_event (SEND, NULL);
I_RRS = add_role ("I_E: Encrypt");
add_event (READ, NULL);
add_event (READ, NULL);
add_event (SEND, NULL);
I_RRSD = add_role ("I_D: Decrypt");
num_regular_runs = 0;
num_intruder_runs = 0;
max_encryption_level = 0;
return;
}
@ -621,9 +632,76 @@ iterate_role_sends (int (*func) ())
return iterate_role_events (send_wrapper);
}
//! Create decryption role instance
/**
* Note that this does not add any bindings for the reads.
*
*@param term The term to be decrypted (implies decryption key)
*
*@returns The run id of the decryptor instance
*/
int
create_decryptor (const Term term, const Term key)
{
if (term != NULL && isTermEncrypt (term))
{
Roledef rd;
Term tempkey;
int run;
run = semiRunCreate (INTRUDER, I_RRSD);
rd = sys->runs[run].start;
rd->message = termDuplicateUV (term);
rd->next->message = termDuplicateUV (key);
rd->next->next->message = termDuplicateUV (TermOp (term));
sys->runs[run].step = 3;
proof_suppose_run (run, 0, 3);
return run;
}
else
{
globalError++;
printf ("Term for which a decryptor instance is requested: ");
termPrint (term);
printf ("\n");
error
("Trying to build a decryptor instance for a non-encrypted term.");
}
}
//! Get the priority level of a key that is needed for a term (typical pk/sk distinction)
int
getPriorityOfNeededKey (const System sys, const Term keyneeded)
{
int prioritylevel;
/* Normally, a key gets higher priority, but unfortunately this is not propagated at the moment. Maybe later.
*/
prioritylevel = 1;
if (realTermEncrypt (keyneeded))
{
/* the key is a construction itself */
if (inKnowledge (sys->know, TermKey (keyneeded)))
{
/* the key is constructed by a public thing */
/* typically, this is a public key, so we postpone it */
prioritylevel = -1;
}
}
return prioritylevel;
}
//! Try to bind a specific existing run to a goal.
/**
* The key goals are bound to the goal.
*
*@todo This is currently NOT correct. The point is that the key chain
* cannot uniquely define a path through a term in general, and
* a rewrite of termMguSubterm is needed. It should not yield the
* needed keys, but simply the path throught the term. This would enable
* reconstruction of the keys anyway. TODO
*
*@param subterm determines whether it is a subterm unification or not.
*/
int
@ -635,7 +713,7 @@ bind_existing_to_goal (const Binding b, const int run, const int index)
int newgoals;
int found;
int subterm_iterate (Termlist substlist, Termlist keylist)
int subterm_iterate (Termlist substlist, Termlist cryptlist)
{
int flag;
@ -644,56 +722,149 @@ bind_existing_to_goal (const Binding b, const int run, const int index)
/**
* Now create the new bindings
*/
if (goal_bind (b, run, index))
{
int newgoals;
Termlist tl;
int newruns;
int stillvalid;
proof_suppose_binding (b);
if (keylist != NULL && sys->output == PROOF)
Binding smalltermbinding;
stillvalid = true; // New stuff is valid (no cycles)
newgoals = 0; // No new goals introduced (yet)
newruns = 0; // New runs introduced
smalltermbinding = b; // Start off with destination binding
#ifdef DEBUG
if (DEBUGL (4))
{
printf ("Trying to bind the small term ");
termPrint (b->term);
printf (" as coming from the big send ");
termPrint (rd->message);
printf (" , binding ");
termPrint (b->term);
printf ("\nCrypted list needed: ");
termlistPrint (cryptlist);
printf ("\n");
}
#endif
if (cryptlist != NULL && sys->output == PROOF)
{
indentPrint ();
eprintf
("This introduces the obligation to produce the following keys: ");
termlistPrint (keylist);
("This introduces the obligation to decrypted the following encrypted subterms: ");
termlistPrint (cryptlist);
eprintf ("\n");
}
newgoals = 0;
tl = keylist;
while (tl != NULL)
/* The order of the cryptlist is inner -> outer */
while (stillvalid && cryptlist != NULL && smalltermbinding != NULL)
{
int keyrun;
/*
* Invariants:
*
* smalltermbinding binding to be satisfied next (and for which a decryptor is needed)
*/
Term keyneeded;
int prioritylevel;
int smallrun;
int count;
Roledef rddecrypt;
Binding bnew;
int res;
/* normally, a key gets higher priority */
prioritylevel = 1;
if (realTermEncrypt (tl->term))
/*
* 1. Add decryptor
*/
keyneeded =
inverseKey (sys->know->inverses, TermKey (cryptlist->term));
prioritylevel = getPriorityOfNeededKey (sys, keyneeded);
smallrun = create_decryptor (cryptlist->term, keyneeded);
rddecrypt = sys->runs[smallrun].start;
termDelete (keyneeded);
newruns++;
/*
* 2. Add goal bindings
*/
count = goal_add (rddecrypt->message, smallrun, 0, 0);
newgoals = newgoals + count;
if (count >= 0)
{
/* the key is a construction itself */
if (inKnowledge (sys->know, TermKey (tl->term)))
if (count > 1)
{
/* the key is constructed by a public thing */
/* typically, this is a public key, so we postpone it */
prioritylevel = -1;
error
("Added more than one goal for decryptor goal 1, weird.");
}
else
{
// This is the unique new goal then
bnew = (Binding) sys->bindings->data;
}
}
/* add the key as a goal */
else
{
// No new binding? Weird, but fair enough
bnew = NULL;
}
newgoals =
newgoals + goal_add (tl->term, b->run_to, b->ev_to,
newgoals + goal_add (rddecrypt->next->message, smallrun, 1,
prioritylevel);
tl = tl->next;
/*
* 3. Bind open goal to decryptor
*/
res = goal_bind (smalltermbinding, smallrun, 2); // returns 0 iff invalid
if (res != 0)
{
// Allright, good binding, proceed with next
smalltermbinding = bnew;
}
else
{
stillvalid = false;
}
/* progression */
cryptlist = cryptlist->next;
}
/*
* Decryptors for any nested keys have been added. Now we can fill the
* final binding.
*/
if (stillvalid)
{
if (goal_bind (smalltermbinding, run, index))
{
proof_suppose_binding (b);
#ifdef DEBUG
if (DEBUGL (4))
{
indentPrint ();
eprintf ("Added %i new goals, iterating.\n", newgoals);
}
#endif
/* Iterate process */
indentDepth++;
flag = flag && iterate ();
indentDepth--;
goal_remove_last (newgoals);
}
else
{
proof_cannot_bind (b, run, index);
}
}
goal_remove_last (newgoals);
while (newruns > 0)
{
semiRunDestroy ();
newruns--;
}
goal_unbind (b);
return flag;
}
@ -2754,7 +2925,8 @@ prune_claim_specifics ()
{
if (arachne_claim_niagree (sys, 0, sys->current_claim->ev))
{
sys->current_claim->count = statesIncrease (sys->current_claim->count);
sys->current_claim->count =
statesIncrease (sys->current_claim->count);
if (sys->output == PROOF)
{
indentPrint ();
@ -2768,7 +2940,8 @@ prune_claim_specifics ()
{
if (arachne_claim_nisynch (sys, 0, sys->current_claim->ev))
{
sys->current_claim->count = statesIncrease (sys->current_claim->count);
sys->current_claim->count =
statesIncrease (sys->current_claim->count);
if (sys->output == PROOF)
{
indentPrint ();

128
src/binding.c
View File

@ -47,7 +47,7 @@ binding_create (Term term, int run_to, int ev_to)
b->ev_from = -1;
b->run_to = run_to;
b->ev_to = ev_to;
goal_graph_destroy();
goal_graph_destroy ();
b->term = term;
b->level = 0;
return b;
@ -104,13 +104,13 @@ goal_graph_destroy ()
struct mallinfo mi_free;
int mem_free;
mi_free = mallinfo();
mi_free = mallinfo ();
mem_free = mi_free.uordblks;
#endif
memFree (graph, (nodes * nodes) * sizeof (int));
graph = NULL;
#ifdef DEBUG
mi_free = mallinfo();
mi_free = mallinfo ();
if (mem_free - mi_free.uordblks != graph_uordblks)
error ("Freeing gave a weird result.");
#endif
@ -137,11 +137,13 @@ goal_graph_create ()
int create_mem_before;
if (graph_uordblks != 0)
error ("Trying to create graph stuff without 0 uordblks for it first, but it is %i.", graph_uordblks);
create_mi = mallinfo();
error
("Trying to create graph stuff without 0 uordblks for it first, but it is %i.",
graph_uordblks);
create_mi = mallinfo ();
create_mem_before = create_mi.uordblks;
graph = memAlloc ((nodes * nodes) * sizeof (int));
create_mi = mallinfo();
create_mi = mallinfo ();
graph_uordblks = create_mi.uordblks - create_mem_before;
}
@ -270,15 +272,17 @@ goal_graph_create ()
// It's read here first.
// Order and be done with it.
graph[graph_nodes
(nodes, run2,
ev2, run,
ev)] = 1;
(nodes,
run2, ev2,
run, ev)] =
1;
#ifdef DEBUG
if (DEBUGL (5))
{
eprintf
("* [local originator] term ");
termPrint (t2);
termPrint
(t2);
eprintf
(" is bound using %i, %i before %i,%i\n",
run2, ev2,
@ -295,7 +299,8 @@ goal_graph_create ()
{
eprintf
("Term ");
termPrint (t2);
termPrint
(t2);
eprintf
(" from run %i occurs in run %i, term ",
run2, run);
@ -310,8 +315,9 @@ goal_graph_create ()
// This forces a loop, and thus prunes
graph
[graph_nodes
(nodes, 0, 1,
0, 0)] = 1;
(nodes, 0,
1, 0,
0)] = 1;
}
}
}
@ -432,9 +438,6 @@ binding_print (const Binding b)
int
goal_add (Term term, const int run, const int ev, const int level)
{
int sum;
sum = 0;
term = deVar (term);
#ifdef DEBUG
if (term == NULL)
@ -447,8 +450,7 @@ goal_add (Term term, const int run, const int ev, const int level)
#endif
if (realTermTuple (term))
{
sum = sum +
goal_add (TermOp1 (term), run, ev, level) +
return goal_add (TermOp1 (term), run, ev, level) +
goal_add (TermOp2 (term), run, ev, level);
}
else
@ -479,17 +481,67 @@ goal_add (Term term, const int run, const int ev, const int level)
b = binding_create (term, run, ev);
b->level = level;
sys->bindings = list_insert (sys->bindings, b);
sum = sum + 1;
#ifdef DEBUG
if (DEBUGL (3))
{
eprintf ("Adding new binding for ");
termPrint (term);
eprintf (" to run %i, ev %i.\n", run, ev);
}
#endif
return 1;
}
}
return sum;
return 0;
}
//! Add a goal, and bind it immediately.
// If the result is negative, no goals will have been added, as the resulting state must be pruned (cycle) */
int
goal_add_fixed (Term term, const int run, const int ev, const int fromrun,
const int fromev)
{
int newgoals, n;
List l;
int res;
newgoals = goal_add (term, run, ev, 0);
l = sys->bindings;
n = newgoals;
res = 1;
while (res != 0 && n > 0 && l != NULL)
{
Binding b;
b = (Binding) l->data;
if (b->done)
{
globalError++;
binding_print (b);
error (" problem with new fixed binding!");
}
res = goal_bind (b, fromrun, fromev); // returns 0 if it must be pruned
l = l->next;
n--;
}
if (res != 0)
{
return newgoals;
}
else
{
goal_remove_last (newgoals);
return -1;
}
}
//! Remove a goal
void
goal_remove_last (int n)
{
while (n > 0 && (sys->bindings != NULL))
while (n > 0)
{
if (sys->bindings != NULL)
{
Binding b;
@ -498,6 +550,13 @@ goal_remove_last (int n)
sys->bindings = list_delete (sys->bindings);
n--;
}
else
{
error
("goal_remove_last error: trying to remove %i too many bindings.",
n);
}
}
}
//! Bind a goal (0 if it must be pruned)
@ -522,6 +581,8 @@ goal_bind (const Binding b, const int run, const int ev)
}
else
{
globalError++;
binding_print (b);
error ("Trying to bind a bound goal again.");
}
}
@ -545,7 +606,8 @@ goal_unbind (const Binding b)
/**
* Especially made for tuple expansion
*/
int binding_block (Binding b)
int
binding_block (Binding b)
{
if (!b->blocked)
{
@ -559,7 +621,8 @@ int binding_block (Binding b)
}
//! Unblock a binding
int binding_unblock (Binding b)
int
binding_unblock (Binding b)
{
if (b->blocked)
{
@ -630,7 +693,8 @@ labels_ordered (Termmap runs, Termlist labels)
}
//! Check whether the binding denotes a sensible thing such that we can use run_from and ev_from
int valid_binding (Binding b)
int
valid_binding (Binding b)
{
if (b->done && !b->blocked)
return 1;
@ -656,7 +720,19 @@ bindings_c_minimal ()
// Recompute closure; does that work?
if (!warshall (graph, nodes))
{
// Hmm, cycle
List l;
globalError++;
l = sys->bindings;
while (l != NULL)
{
Binding b;
b = (Binding) l->data;
binding_print (b);
eprintf ("\n");
l = l->next;
}
error ("Detected a cycle when testing for c-minimality");
}
}
@ -669,7 +745,7 @@ bindings_c_minimal ()
b = (Binding) bl->data;
// Check for a valid binding; it has to be 'done' and sensibly bound (not as in tuple expanded stuff)
if (valid_binding(b))
if (valid_binding (b))
{
int run;
int node_from;

2
src/binding.h
View File

@ -43,6 +43,8 @@ int binding_print (Binding b);
int valid_binding (Binding b);
int goal_add (Term term, const int run, const int ev, const int level);
int goal_add_fixed (Term term, const int run, const int ev, const int fromrun,
const int fromev);
void goal_remove_last (int n);
int goal_bind (const Binding b, const int run, const int ev);
void goal_unbind (const Binding b);

6
src/compiler.c
View File

@ -1018,9 +1018,13 @@ order_label_roles (const Claimlist cl)
int scan_label (void *data)
{
Labelinfo linfo;
Termlist tl;
linfo = (Labelinfo) data;
if (inTermlist (cl->prec, linfo->label))
if (linfo == NULL)
return 1;
tl = cl->prec;
if (inTermlist (tl, linfo->label))
{
if (linfo->protocol == cl->protocol)
{

62
src/mgu.c
View File

@ -104,8 +104,7 @@ goodsubst (Term tvar, Term tsubst)
else
{
// It's a leaf, but what type?
if (mgu_match == 1
|| compatibleTypes ())
if (mgu_match == 1 || compatibleTypes ())
{
return 1;
}
@ -305,68 +304,69 @@ termMguInTerm (Term t1, Term t2, int (*iterator) (Termlist))
return flag;
}
//! Most general subterm unifiers of t1 subterm t2
//! Most general subterm unifiers of smallterm subterm bigterm
/**
* Try to determine the most general subterm unifiers of two terms.
*@returns Nothing. Iteration gets termlist of subst, and list of keys needed to decrypt.
*@returns Nothing. Iteration gets termlist of subst, and list of keys needed
* to decrypt. This termlist does not need to be deleted, because it is handled
* by the mguSubTerm itself.
*/
int
termMguSubTerm (Term t1, Term t2, int (*iterator) (Termlist, Termlist),
Termlist inverses, Termlist keylist)
termMguSubTerm (Term smallterm, Term bigterm,
int (*iterator) (Termlist, Termlist), Termlist inverses,
Termlist cryptlist)
{
int flag;
flag = 1;
t1 = deVar (t1);
t2 = deVar (t2);
if (t2 != NULL)
smallterm = deVar (smallterm);
bigterm = deVar (bigterm);
if (bigterm != NULL)
{
Termlist tl;
if (!realTermLeaf (t2))
if (!realTermLeaf (bigterm))
{
if (realTermTuple (t2))
if (realTermTuple (bigterm))
{
// 'simple' tuple
flag =
flag && termMguSubTerm (t1, TermOp1 (t2), iterator, inverses,
keylist);
flag =
flag && termMguSubTerm (t1, TermOp2 (t2), iterator, inverses,
keylist);
flag
&& termMguSubTerm (smallterm, TermOp1 (bigterm), iterator,
inverses, cryptlist);
flag = flag
&& termMguSubTerm (smallterm, TermOp2 (bigterm), iterator,
inverses, cryptlist);
}
else
{
// Must be encryption
// So, we need the key, and try to get the rest
Term newkey;
Term keyneeded;
newkey = inverseKey (inverses, TermKey (t2));
keyneeded = inverseKey (inverses, TermKey (bigterm));
// We can never produce the TERM_Hidden key, thus, this is not a valid iteration.
if (!isTermEqual (newkey, TERM_Hidden))
if (!isTermEqual (keyneeded, TERM_Hidden))
{
Termlist keylist_new;
keylist_new = termlistShallow (keylist);
keylist_new = termlistAdd (keylist_new, newkey);
cryptlist = termlistAdd (cryptlist, bigterm); // Append, so the last encrypted term in the list is the most 'inner' one, and the first is the outer one.
// Recurse
flag =
flag
&& termMguSubTerm (t1, TermOp (t2), iterator, inverses,
keylist_new);
&& termMguSubTerm (smallterm, TermOp (bigterm), iterator,
inverses, cryptlist);
termlistDelete (keylist_new);
cryptlist = termlistDelTerm (cryptlist);
}
termDelete (newkey);
termDelete (keyneeded);
}
}
// simple clause or combined
tl = termMguTerm (t1, t2);
tl = termMguTerm (smallterm, bigterm);
if (tl != MGUFAIL)
{
// Iterate
flag = flag && iterator (tl, keylist);
flag = flag && iterator (tl, cryptlist);
// Reset variables
termlistSubstReset (tl);
// Remove list
@ -375,7 +375,7 @@ termMguSubTerm (Term t1, Term t2, int (*iterator) (Termlist, Termlist),
}
else
{
if (t1 != NULL)
if (smallterm != NULL)
{
flag = 0;
}

1
src/system.c
View File

@ -101,6 +101,7 @@ systemInit ()
sys->roleeventmax = 0;
sys->claimlist = NULL;
sys->labellist = NULL;
sys->match = 0; // default matching
/* matching CLP */
sys->constraints = NULL; // no initial constraints

4
src/term.c
View File

@ -683,7 +683,7 @@ tupleCount (Term tt)
//! Yield the projection Pi(n) of a term.
/**
*@param tt Term
*@param n The index in the tuple.
*@param n The index in the tuple [0..tupleCount-1]
*@return Returns either a pointer to a term, or NULL if the index is out of range.
*\sa tupleCount()
*/
@ -1085,7 +1085,7 @@ term_encryption_level (const Term term)
if (t == NULL)
{
#ifdef DEBUG
if (DEBUGL(2))
if (DEBUGL (2))
{
eprintf ("Warning: Term encryption level finds a NULL for term ");
termPrint (term);

6
src/termlist.c
View File

@ -272,7 +272,8 @@ termlistConcat (Termlist tl1, Termlist tl2)
//! Remove the pointed at element from the termlist.
/**
* Easier because of the double linked list.
* Easier because of the double linked list. Note: does not do termDelete on the term.
*
*@param tl The pointer to the termlist node to be deleted from the list.
*@return The possibly new head pointer to the termlist.
*/
@ -667,8 +668,7 @@ termlistLocal (Termlist tl, const Termlist fromlist, const Termlist tolist)
while (tl != NULL)
{
newtl =
termlistAdd (newtl, termLocal (tl->term, fromlist, tolist));
newtl = termlistAdd (newtl, termLocal (tl->term, fromlist, tolist));
tl = tl->next;
}
return newtl;