scyther/scripts/if2spdl/parser.py
2005-11-16 19:50:40 +00:00

119 lines
3.4 KiB
Python
Executable File

#!/usr/bin/python
# requires python-pyparsing module
# http://pyparsing.sourceforge.net/
from pyparsing import Word, alphanums, alphas, nums, oneOf, restOfLine, OneOrMore, \
ParseResults, Forward, Combine, Or, Optional,MatchFirst, \
ZeroOrMore, StringEnd, LineEnd, delimitedList, Group, Literal
import Term
def ifParse (str):
# Tokens
lbr = Literal("(").suppress()
rbr = Literal(")").suppress()
com = Literal(",").suppress()
hash = Literal("#").suppress()
equ = Literal("=").suppress()
implies = Literal("=>").suppress()
# Functions to construct tuples etc
def bracket(x):
return lbr + x + rbr
def ntup(n):
x = Message
while n > 1:
x = x + com + Message
n = n - 1
return x
def btup(n):
return bracket(ntup(n))
def funcy(x,y):
return x + bracket(y)
def ftup(x,n):
return funcy(x, ntup(n))
# Message section
Alfabet= alphas+nums+"_$"
Variable = Word("x",Alfabet).setParseAction(lambda s,l,t: [ Term.TermVariable(t[0],None) ])
Constant = Word(alphas,Alfabet).setParseAction(lambda s,l,t: [ Term.TermConstant(t[0]) ])
Number = Word(nums).setParseAction(lambda s,l,t: [ Term.TermConstant(t[0]) ])
Basic = MatchFirst([ Variable, Constant, Number ])
# Message definition is recursive
Message = Forward()
def parseType(s,l,t):
if t[0][0] == "pk":
# Public key thing, that's not really a type for
# us but a function
return [Term.TermEncrypt(t[0][1], t[0][0]) ]
term = t[0][1]
term.setType(t[0][0])
return [term]
TypeInfo = oneOf ("mr nonce pk sk fu table").setParseAction(lambda s,l,t: [ Term.TermConstant(t[0]) ])
TypeMsg = Group(TypeInfo + lbr + Message + rbr).setParseAction(parseType)
def parseCrypt(s,l,t):
# Crypto types are ignored for now
type = t[0][0]
if type == "c":
return [Term.TermTuple( t[0][1],t[0][2] ) ]
return [Term.TermEncrypt(t[0][2],t[0][1])]
CryptOp = oneOf ("crypt scrypt c funct rcrypt tb")
CryptMsg = Group(CryptOp + lbr + Message + com + Message + rbr).setParseAction(parseCrypt)
def parseSMsg(s,l,t):
return [Term.TermEncrypt(t[0][1],Term.Termconstant("succ") )]
SMsg = Group(Literal("s") + lbr + Message + rbr)
def parsePrime(s,l,t):
# for now, we simply ignore the prime (')
return [t[0][0]]
Message << Group(Or ([TypeMsg, CryptMsg, SMsg, Basic]) + Optional(Literal("'"))).setParseAction(parsePrime)
# Fact section
Request = Group("request" + btup(4))
Witness = Group("witness" + btup(4))
Give = Group("give" + lbr + Message + com + ftup(Literal("f"),
1) + rbr)
Secret = Group("secret" + lbr + Message + com +
ftup(Literal("f"),1) + rbr)
TimeFact = Group(ftup (Literal("h"), 1))
IntruderKnowledge = Group(ftup (Literal("i"), 1))
MessageFact = Group(ftup(Literal("m"),6))
Principal = Group(ftup(Literal("w"), 7))
Fact = Principal | MessageFact | IntruderKnowledge | TimeFact | Secret | Give | Witness | Request
#State = Fact + OptioZeroOrMore ("." + Fact)
State = Group(delimitedList (Fact, "."))
# Rules and labels
rulename = Word (alphanums + "_")
rulecategory = oneOf("Protocol_Rules Invariant_Rules Decomposition_Rules Intruder_Rules Init Goal")
label = hash + "lb" + equ + rulename + com + "type" + equ + rulecategory
rule = Group(State + Optional(implies + State))
labeledrule = Group(label + rule)
typeflag = hash + "option" + equ + oneOf ("untyped","typed")
# A complete file
iffile = typeflag + Group(OneOrMore(labeledrule))
parser = iffile
parser.ignore("##" + restOfLine)
return parser.parseString(str)