142 lines
4.1 KiB
Python
Executable File
142 lines
4.1 KiB
Python
Executable File
#!/usr/bin/python
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"""
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Example script to show how to perform large-scale tests using the
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Scyther Python API (contained in the Scyther subdirectory)
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In this example, multi-protocol attack analysis is performed on a small
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test set.
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"""
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import Scyther.Scyther as Scyther
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def MyScyther(protocollist,filter=None):
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"""
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Evaluate the composition of the protocols in protocollist.
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If there is a filter, i.e. "ns3,I1" then only this specific claim
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will be evaluated.
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"""
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s = Scyther.Scyther()
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s.options = "--match=2"
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if filter:
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s.options += " --filter=%s" % (filter)
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for protocol in protocollist:
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s.addFile(protocol)
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s.verify()
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return s
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def getCorrectIsolatedClaims(protocolset):
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"""
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Given a set of protocols, determine the correct claims when run in
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isolation.
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Returns a tuple, consisting of
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- a list of compiling protocols
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- a list of tuples (protocol,claimid) wich denote correct claims
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"""
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correctclaims = []
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goodprotocols = []
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for protocol in protocolset:
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# verify protocol in isolation
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s = MyScyther([protocol])
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# investigate the results
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if not s.errors:
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goodprotocols.append(protocol)
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for claim in s.claims:
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if claim.okay:
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correctclaims.append((protocol,claim.id))
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return (goodprotocols,correctclaims)
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def verifyMPAlist(mpalist,claimid):
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"""
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Verify the existence of an attack in this context
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If an attack is found, we return False, otherwise True. This is
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needed for the iteration later.
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"""
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# This should be a more restricted verification
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s = MyScyther(mpalist,claimid)
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claim = s.getClaim(claimid)
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if claim:
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if not claim.okay:
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# This is an MPA attack!
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print "I've found a multi-protocol attack on claim %s in the context %s." % (claimid,str(mpalist))
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return False
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else:
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return True
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def constructMPAlist(protocolset,claimid,mpalist,length,start,callback):
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"""
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Append a list of parallel protocols, without duplicates,
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such that the added part is lexicographically ordered (from
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index 'start' in the protocol list)
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For each possible list, the function callback is called. If the
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callback returns true, iteration proceeds (returning true in the
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end), otherwise it aborts and returns false.
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"""
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if len(mpalist) < length:
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# list is not long enough yet
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for pn in range(start,len(protocolset)):
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p = protocolset[pn]
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if p not in mpalist:
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if not constructMPAlist(protocolset,claimid,mpalist + [p],length,pn+1,callback):
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return False
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return True
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else:
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# list is long enough: callback
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return callback(mpalist,claimid)
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def findMPA(protocolset,protocol,claimid,maxcount=3):
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"""
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The protocol claim is assumed to be correct. When does it break?
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"""
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# First we examine 2-protocol attacks, and then increase the
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# number of parallel protocols if we don't find any attacks on the
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# claim.
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count = 2
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if len(protocolset) < maxcount:
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# we cannot have more protocols in parallel than there are
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# protocols.
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maxcount = len(protocolset)
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# the actual incremental search loop
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while count <= maxcount:
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constructMPAlist(protocolset,claimid,[protocol],count,0,verifyMPAlist)
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count += 1
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return None
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def findAllMPA(protocolset,maxcount=3):
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"""
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Given a set of protocols, find multi-protocol attacks
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"""
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# Find all correct claims in each protocol
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(protocolset,correct) = getCorrectIsolatedClaims(protocolset)
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# For all these claims...
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for (protocol,claimid) in correct:
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# Try to find multi-protocol attacks
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findMPA(protocolset,protocol,claimid,maxcount=3)
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if __name__ == '__main__':
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"""
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Simple test case with a few protocols
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"""
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list = ['me.spdl','ns3.spdl','nsl3.spdl']
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print "Performing multi-protocol analysis for the following protocols:", list
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print
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findAllMPA(list)
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print
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print "Analysis complete."
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