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- Improved heuristics. Default is now 162 (but 99 performs equally well)

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This commit is contained in:
ccremers 2006-06-29 07:49:23 +00:00
parent d87d9ede30
commit c52a340d8e
2 changed files with 49 additions and 3 deletions
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48
src/heuristic.c
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@ -236,6 +236,39 @@ newkeylevel (const int level)
return 1;
}
//! count local constants
float
term_constcount (const System sys, Term t)
{
int n, total;
float ratio;
int countMe (Term t)
{
if (TermRunid (t) >= 0)
{
total++;
if (!isTermVariable (t))
{
n++;
}
}
}
n = 0;
total = 0;
term_iterate_deVar (t, countMe, NULL, NULL, NULL);
if (total == 0)
{
ratio = 1;
}
else
{
ratio = ((total - n) / total);
}
return ratio;
}
//! Determine the weight of a given goal
/**
* 0 to ... (lower is better)
@ -287,11 +320,24 @@ computeGoalWeight (const System sys, const Binding b)
// Bit 3: 8 nonce variables level (Cf. what I think is in Athena)
erode (term_noncevariables_level (t));
// Bit 4: 16 use hidelevel (normal)
erode (1 * weighHidelevel (sys, t, 0.5, 0.5));
// Bit 5: 32 use known nonces (Athena try 2)
erode (term_constcount (sys, t));
// Bit 6: 64 use hidelevel (but only single-weight)
erode (weighHidelevel (sys, t, 0.5, 0.5));
// Bit 7: 128 use hidelevel (quadruple-weight)
erode (4 * weighHidelevel (sys, t, 0.5, 0.5));
// Bit 8: 256 use known nonces (Athena try 2), half weight
erode (0.5 * term_constcount (sys, t));
// Define legal range
if (smode > 0)
error ("--heuristic mode %i is illegal", switches.heuristic);
// Return total weight
// Return
return w;
}

4
src/switches.c
View File

@ -49,7 +49,7 @@ switchesInit (int argc, char **argv)
switches.maxAttacks = 0; // no maximum default
// Arachne
switches.heuristic = 3; // default goal selection method
switches.heuristic = 162; // default goal selection method
switches.maxIntruderActions = INT_MAX; // max number of encrypt/decrypt events
switches.agentTypecheck = 1; // default do check agent types
switches.concrete = true; // default removes symbols, and makes traces concrete
@ -829,7 +829,7 @@ switcher (const int process, int index, int commandline)
{
if (switches.expert)
{
helptext (" --heuristic=<int>", "use heuristic <int> [3]");
helptext (" --heuristic=<int>", "use heuristic <int> [162]");
}
}
else