- Working version.

spdl/multiparty/mp-nsl.py

@@ -2,35 +2,214 @@
 #
 # Generate Multi-party NSL protocol description for n parties
 #
+# Input: P variant
+#
+# variant uses some bits:
+#	bit	mask	meaning if set to '1'
+#			message type 1
+# 	0	1	agents in reverse 
+# 	1	2	nonces after agents
+# 	2	4	nonces in reverse 
+# 	3	8	interleaved variant
+# 			message type 2
+# 	4	16	nonces in reverse in message 2
+#
+import sys
 
-def llist (n):
+def role (r):
 	global P
 
-	s = ""
+	return "R%i" % (r % P)
-	first = 1
+
-	for i in range(0,P):
+def nonce (r):
-		if n != i:
+	global P
-			if first:
+
-				first = 0
+	return "n%i" % (r % P)
+
+def extend (s1, s2):
+	if s1 == "":
+		return s2
 	else:
-				s = s + ","
+		return s1 + "," + s2
-			s = s + "r%i" % (i)
+
-	return s
+def weavel (l1,l2,reverse1,swap,reverse2,interleave):
+	""" l1 is typically a list of nonces, l2 might be empty (names) """
+	global variant
+
+	if reverse1:
+		l1.reverse()
+	if l2 == []:
+		return l1
+	else:
+		if reverse2:
+			l2.reverse()
+		if swap:
+			# swap
+			l3 = l1
+			l1 = l2
+			l2 = l3
+		if interleave:
+			rl = []
+			largest = max(len(l1),len(l2))
+			for i in range (0,largest):
+				if i < len(l1):
+					rl.append(l1[i])
+				if i < len(l2):
+					rl.append(l2[i])
+			return rl
+		else:
+			return l1 + l2
 
 def message1 (label):
+	global P,variant
+
+	noncelist = []
+	for i in range(0,label+1):
+		noncelist.append(nonce(i))
+	rolelist = []
+	for i in range(0,P):
+		if i != (label+1) % P:
+			rolelist.append(role(i))
+
+	return ",".join(weavel(noncelist,rolelist,
+		(variant & 1 != 0),
+		(variant & 2 != 0),
+		(variant & 4 != 0),
+		(variant & 8 != 0)
+		))
+
+def message2 (label):
+	global P,variant
+
+	noncelist = []
+	for i in range (((label + 1) % P),P):
+		noncelist.append(nonce(i))
+
+	return ",".join(weavel(noncelist,[],
+		(variant & 16 != 0),
+		False,
+		False,
+		False
+		))
+
+def message (label):
 	global P
 
 	s = "{ "
-	for i in range (0,label+1):
+	if label < P:
-		if i>0:
+		s = s + message1 (label)
-			s = s + ","
+	else:
-		s = s + "n%i" % (i)
+		s = s + message2 (label)
-	s = s + ","
+
-	s = s + llist((label+1) % P)
+	s = s + " }pk(%s)" % role(label+1)
-	s = s + " }pk(r%i)" % ((label+1) % P)
 	return s
 
-P = 4
+def action (event,label):
-print message1 (1)
+	s = "\t\t%s_%i(%s,%s, " % (event,label, role(label),
+			role(label+1))
+	s += message (label)
+	s += " );\n"
+	return s
+
+def read (label):
+	return action ("read", label)
 
 
+def send (label):
+	return action ("send", label)
+
+def roledef (r):
+	global P
+
+	s = ""
+	s += "\trole " + role(r) + "\n\t{\n"
+
+	# constants for this role
+	
+	s += "\t\tconst " + nonce (r) + ": Nonce;\n"
+
+	# variables
+	
+	s += "\t\tvar "
+	nr = 0
+	for i in range (0,P):
+		if r != i:
+			if nr > 0:
+				s += ","
+			s += nonce(i)
+			nr += 1
+
+	s += ": Nonce;\n"
+		
+	# actions
+	
+	s += "\n"
+	if r > 0:
+		# Initial read
+		s += read(r-1)
+	s += send(r)
+	s += read(P+r-1)
+	if r < (P-1):
+		# Final send
+		s += send(P+r)
+	
+	# claims
+	
+	s += "\t\tclaim_%sa( %s, Secret, %s );\n" % (role(r), role(r),
+			nonce(r))
+	s += "\t\tclaim_%sb( %s, Nisynch );\n" % (role(r), role(r))
+
+	# close
+	s += "\t}\n\n"
+	return s
+
+
+def protocol (pset,vset):
+	global P,variant
+
+	P = pset
+	variant = vset
+
+	s = ""
+	s += "// Generalized Needham-Schroeder-Lowe for %i parties\n\n" % P
+	s += "// Variant %i\n" % variant
+	s += "const pk: Function;\n"
+	s += "secret sk: Function;\n"
+	s += "inversekeys (pk,sk);\n\n"
+
+	s += "protocol mnsl%iv%i(" % (P,variant)
+	for i in range (0,P):
+		if i > 0:
+			s += ","
+		s += role(i)
+	s += ")\n{\n"
+
+	for i in range (0,P):
+		s += roledef(i)
+	
+	s += "}\n\n"
+
+	s += "const Alice, Bob: Agent;\n\n"
+
+	s += "const Eve: Agent;\n"
+	s += "untrusted Eve;\n"
+	s += "const ne: Nonce;\n"
+	s += "compromised sk(Eve);\n"
+
+	s += "\n"
+	return s
+
+def main():
+	if len(sys.argv) < 3:
+		print "We need at least 2 arguments: number of parties, and variant"
+		print "Note that variant is in [0..31]"
+		print ""
+		print "E.g. './multinsl-generator.py 2 0' yields a default NSL protocol"
+	else:
+		print protocol(int (sys.argv[1]), int(sys.argv[2]))
+
+# Only if main stuff
+if __name__ == '__main__':
+	main()
+else:
+	print protocol (2,0)