#!/usr/bin/python # # Multi-protocol test using Scyther # # (c)2004 Cas Cremers # # Input of this script: # # - A number on the commandline of stuff to test # - A list of files on stdin to be used (lines starting with '#' are # ignored) # # # Tips and tricks: # # Use e.g. # $ ulimit -v 100000 # to counteract memory problems # # If you know where to look, use # $ ls s*.spdl t*.spdl -1 | ./multiprotocoltest.py 2 # To verify combos of protocols starting with s and t # import tuplesdo import copy import scythercache from tempfile import NamedTemporaryFile # *********************** # EXPERIMENTS # *********************** ### Test 0-2 ###------------------------------------------------------------------ TupleWidth = "2" ScytherMethods = "--match=0 --arachne" ScytherBounds = "--timer=5 --max-runs=5 --max-length=20" ### Test 1-2 ###------------------------------------------------------------------ #TupleWidth = "2" #ScytherMethods = "--match=1 --arachne" #ScytherBounds = "--timer=5 --max-runs=5 --max-length=20" # *********************** # PARAMETERS # *********************** # Temporary files TempFileList = "scyther-blap.tmp" TempFileTuples = "scyther-blip.tmp" # External programs TupleProgram = "./tuples.py" # Scyther parameters ScytherDefaults = "--summary" # Build a large part of the command line (for Scyther) already ScytherArgs = ScytherDefaults + " " + ScytherMethods + " " + ScytherBounds CommandPrefix = "scyther " + ScytherArgs # Some default settings for Agents, untrusted e with sk(e) and k(a,e) etc. IncludeProtocols = '../spdl/spdl-defaults.inc' # Some protocols are causing troubles: this is a hard-coded filter to exclude # the problem children. Unfair, yes. Practical, yes. #SkipList = [ 'gong-nonce.spdl', 'gong-nonce-b.spdl', 'splice-as-hc.spdl', 'kaochow-palm.spdl' ] SkipList = [] ClaimToResultMap = {} # maps protocol claims to correctness in singular tests (0,1) ProtocolToFileMap = {} # maps protocol names to file names ProtocolToStatusMap = {} # maps protocol names to status: 0 all false, 1 all correct, otherwise (2) mixed ProtocolToEffectsMap = {} # maps protocols that help create multiple flaws, to the protocol names of the flaws they caused # Ugly hack. Works. safetxt = " " * 20 # *********************** # MODULES # *********************** import os import sys import string import commands # *********************** # LIBS # *********************** # GetKeys # # Given a mapping f and a value x, returns a list of keys # k for which f(k) = x def GetKeys (f, x): res = [] for k in f.keys(): if f[k] == x: res.append(k) return res # GetListKeys # # Given a mapping f and a list l, returns a list of keys # k for which f(k) = x, x in l def GetListKeys (f, l): res = [] for x in l: for y in GetKeys (f, x): if y not in res: res.append(y) return res # CommandLine # # Yield the commandline to test, given a list of protocols def CommandLine (plist): linelist = " ".join(plist) return "cat " + IncludeProtocols + " " + linelist + " | " + CommandPrefix # PrintProtStatus # # pretty-print the status of a protocol def PrintProtStatus (file, prname): file.write (prname + ": ") if ProtocolToStatusMap[prname] == 0: file.write ("All-Flawed") elif ProtocolToStatusMap[prname] == 1: file.write ("All-Correct") else: file.write ("Mixed") # ScytherEval # # Take the list of protocols in plist, and give them to Scyther. # Returns a dictionary of claim -> bool; where 1 means that it is # correct, and 0 means that it is false (i.e. there exists an attack) def ScytherEval (plist): results = {} # Flush before trying (possibly fatal) external commands sys.stdout.flush() sys.stderr.flush() # Combine protocol list to an input input = "" for fn in plist: f = open(fn, "r") input = input + f.read() f.close() # Use Scyther (status,scout) = scythercache.eval(ScytherArgs,input) if status == 1 or status < 0: # Something went wrong print "*** Error when checking [" + CommandLine (plist) + "]\n" return results lines = scout.splitlines() for line in lines: data = line.split() if len(data) > 6 and data[0] == 'claim': claim = " ".join(data[1:4]) tag = data[6] value = -1 if tag == 'failed:': value = 0 if tag == 'correct:': value = 1 if value == -1: raise IOError, 'Scyther output for ' + commandline + ', line ' + line + ' cannot be parsed.' results[claim] = value return results # ScytherEval1 # # The above, but do the preprocessing for a single protocol def ScytherEval1 (protocol): results = ScytherEval ([protocol]) # Add the claim to the list of ClaimToResultMap for claim in results.keys(): if ClaimToResultMap.has_key(claim): # Claim occurs in two protocols; determine the # files file1 = ProtocolToFileMap[claim.split()[0]] file2 = protocol raise IOError, 'Claim occurs in two protocols: ' + claim + ", in files (" + file1 + ") and (" + file2 + ")" # Add the filename to the protocol mappings prname = claim.split()[0] if ProtocolToFileMap.has_key(prname): # We already wrote this down # # TODO The mapping should not conflict, but we don't # check that now (covered by claim duplication # in a sense) # # Compare previous result, maybe mixed if ProtocolToStatusMap[prname] <> results[claim]: ProtocolToStatusMap[prname] = 2 else: # New one, store the first result ProtocolToFileMap[prname] = protocol ProtocolToStatusMap[prname] = results[claim] ClaimToResultMap.update (results) # Show progress of i (0..n) # LastProgress = {} ProgressBarWidth = 50 def ShowProgress (i,n,txt): def IntegerPart (x): return int (( x * i ) / n) percentage = IntegerPart (100) factor = IntegerPart (ProgressBarWidth) showme = 0 if LastProgress.has_key(n): if LastProgress[n]<>(factor,txt): showme = 1 else: showme = 1 if showme == 1: bar = "\r[" i = 0 while i < ProgressBarWidth: if i <= factor: bar = bar + "*" else: bar = bar + "." i = i+1 bar = bar + "] %3d%% " % percentage + txt sys.stderr.write(bar) sys.stderr.flush() LastProgress[n] = (factor, txt) def ClearProgress (n,txt): bar = " " * (1 + ProgressBarWidth + 2 + 5 + len(txt)) sys.stderr.write("\r" + bar + "\r") sys.stderr.flush() def DescribeContextBrief (filep, protocols, claim, prefix): filep.write (prefix) prlist = [] for prfile in protocols: prnames = GetKeys (ProtocolToFileMap, prfile) prlist = prlist + prnames newprname = claim.split()[0] filep.write ("\t" + newprname) filep.write ("\t" + claim) prlistclean = [] prliststr = "" for pn in prlist: if pn not in prlistclean: if pn != newprname: prlistclean.append(pn) prliststr = prliststr + "\t" + pn filep.write (prliststr) filep.write ("\n") def DescribeContext (filep, protocols, claim): def DC_Claim(cl,v): if v == 0: filep.write ("- " + cl + " : false in both cases") elif v == 1: filep.write ("+ " + cl + " : correct in both cases") elif v == 2: filep.write ("* " + cl + " : newly false in multi-protocol test") else: filep.write ("???") filep.write ("\n") filep.write ("-- Attack description.\n\n") filep.write ("Involving the protocols:\n") for prfile in protocols: prnames = GetKeys (ProtocolToFileMap, prfile) filep.write ("- " + prfile + ": " + ",".join(prnames) + "\n") newprname = claim.split()[0] newprfile = ProtocolToFileMap[newprname] filep.write ("The new attack occurs in " + newprfile + ": " + newprname) filep.write ("\n\n") filep.write (" $ " + CommandLine (protocols) + "\n") filep.write ("\n") DC_Claim (claim, 2) # Determine, for each protocol name within the list of files, # which claims fall under it, and show their previous status for prname in ProtocolToFileMap: # Protocol name if ProtocolToFileMap[prname] in protocols: # prname is a protocol name within the scope # first print isolation correct files (skipping # the claim one, because that is obvious) # construct list of claims for this protocol cllist = [] for cl in ClaimToResultMap.keys(): if cl.split()[0] == prname: cllist.append( (cl,ClaimToResultMap[cl]) ) # We want to show some details, in any case of # the protocol of the claim. However, if the # partner protocol is completely correct or # completely false, we summarize. summary = 0 all = 0 if claim.split()[0] <> prname: count = [0,0] for cl,v in cllist: count[v] = count[v]+1 if count[0] == 0 and count[1] > 0: all = 1 summary = 1 if count[1] == 0 and count[0] > 0: all = 0 summary = 1 if summary == 1: DC_Claim (cl.split()[0] + " *ALL*", all) else: for cl,v in cllist: if v == 1 and cl <> claim: DC_Claim(cl,1) for cl,v in cllist: if v == 0 and cl <> claim: DC_Claim(cl,0) filep.write ("\n") # # Determine whether the attack is really only for this combination of protocols (and not with less) # # returns 0 if it could be done with less also # returns 1 if it really requires these protocols # def RequiresAllProtocols (protocols, claim): # check for single results if ClaimToResultMap[claim] == 0: # claim was always false return 0 # check for simple cases if int(TupleWidth) <= 2: # nothing to remove return 1 # test the claims when removing some others # for TupleWidth size list, we can remove TupleWidth-1 # protocols, and test clprname = claim.split()[0] claimfile = ProtocolToFileMap[clprname] for redundantfile in protocols: if redundantfile != claimfile: # for this particular option, construct a list simplercase = copy.copy(protocols) simplercase.remove(redundantfile) # now test the validity of the claim simplerresults = ScytherEval (simplercase) if simplerresults[claim] == 0: # Redundant protocol was not necessary for attack! return 0 return 1 # # Signal that there is an attack, claim X using protocols Y # # Returns number of new attacks found # def SignalAttack (protocols, claim): if RequiresAllProtocols (protocols, claim) == 0: return 0 ClearProgress (TupleCount, safetxt) outs = "***\t" + str(newattacks) outs = outs + "\t" + str(processed) + "/" + str(TupleCount) for helper in GetListKeys (ProtocolToFileMap, protocols): clprname = claim.split()[0] if helper <> clprname: if helper not in ProtocolToEffectsMap.keys(): # new ProtocolToEffectsMap[helper] = [clprname] else: # already noted as helper, add destruction now if clprname not in ProtocolToEffectsMap[helper]: ProtocolToEffectsMap[helper].append(clprname) # # TODO # # Generate output to recreate/draw the # attack, and maybe add this to a big # error log thingy. Furthermore, # explicitly recreate the commandline # and the claim that is newly violated DescribeContextBrief (sys.stdout, protocols, claim, outs) return 1 # *********************** # MAIN CODE # *********************** # Pass std input to temporary file (list of protocol files) #---------------------------------------------------------------------- # # Determines: # ProtocolCount # ProtocolFileList[0..count-1] # # Furthermore, TempFileList is created. # Where should we start (if this is a number) if len(sys.argv) > 1: StartPercentage = int (sys.argv[1]) if StartPercentage < 0 or StartPercentage > 100: print "Illegal range for starting percentage (0-100):", StartPercentage sys.exit() else: StartPercentage = 0 # Read stdin into list and count, send to file loop = 1 ProtocolCount = 0 ProtocolFileList = [] outp = open(TempFileList, 'w') while loop: line = sys.stdin.readline() if line != '': # not the end of the input cleanline = string.strip(line) if cleanline != '' and cleanline[0] != '#' and cleanline not in SkipList: # not a blank line, not forbidden ProtocolFileList.append(cleanline) ProtocolCount = ProtocolCount + 1 outp.write(line) else: # end of the input loop = 0 outp.close() # Caching of single-protocol results for speed gain. #---------------------------------------------------------------------- # # The script first computes the singular results for all the protocols # and stores this in an array, or something like that. print "Evaluating tuples of", TupleWidth, "for", ProtocolCount, "protocols, using the command '" + CommandPrefix + "'" i = 0 while i < ProtocolCount: ShowProgress (i, ProtocolCount,ProtocolFileList[i]+safetxt) ScytherEval1 ( ProtocolFileList[i] ) i = i + 1 ClearProgress(ProtocolCount, safetxt) print "Evaluated single results." # Show classification #---------------------------------------------------------------------- # print "Correct protocols: ", GetKeys (ProtocolToStatusMap, 1) print "Partly flawed protocols: ", GetKeys (ProtocolToStatusMap, 2) print "Completely flawed protocols: ", GetKeys (ProtocolToStatusMap, 0) # Computation of combined list. #---------------------------------------------------------------------- # # We use the tuple script to generate the list of tuples we need. # We use a temporary file (again) to store that list. # This requires that 'tuples.py' is in the same directory. lstatus=os.system(TupleProgram + ' ' + TupleWidth + ' <' + TempFileList + ' >' + TempFileTuples) inp = open(TempFileTuples, 'r') TupleCount = 0 for x in inp: TupleCount = TupleCount + 1 inp.close() print "Commencing test for", TupleCount, "protocol combinations." # Testing of protocol tuples #---------------------------------------------------------------------- # # We take the list of tuples and test each combination. inp = open(TempFileTuples, 'r') processed = 0 newattacks = 0 StartSkip = 0 # Possibly skip some if StartPercentage > 0: StartSkip = int ((TupleCount * StartPercentage) / 100) print "Resuming. Skipping the first", StartSkip,"tuples." # # Check all these protocols # for tline in inp: if (processed >= StartSkip): # # Get the next tuple # protocols = tline.split() ShowProgress (processed, TupleCount, " ".join(protocols) + safetxt) # # Determine whether there are valid claims at all in # this set of file names # has_valid_claims = 0 for prname in GetListKeys (ProtocolToFileMap, protocols): if ProtocolToStatusMap[prname] != 0: has_valid_claims = 1 if has_valid_claims == 1: # # Use Scyther to verify the claims # results = ScytherEval ( protocols ) # # Now we have the results for this combination. # Check whether any of these claims is 'newly false' # for claim,value in results.items(): if value == 0: # Apparently this claim is false now (there is # an attack) newattacks = newattacks + SignalAttack (protocols, claim) # Next! processed = processed + 1 inp.close() ClearProgress (TupleCount, safetxt) print "Processed", processed,"tuple combinations in total." if StartSkip > 0: print "In this session, checked the last",(processed - StartSkip),"tuples. " print "Found", newattacks, "new attacks." if newattacks > 0: print " These were helped by:" for helper in ProtocolToEffectsMap.keys(): sys.stdout.write (" ") PrintProtStatus (sys.stdout, helper) sys.stdout.write (". This possibly breaks " + str(ProtocolToEffectsMap[helper]) + "\n") sys.stdout.flush() sys.stderr.flush()