#!/usr/bin/python

# $Id$
#
# This file is part of seppl.
#
# seppl is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# seppl is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with seppl; if not, write to the Free Software Foundation,
# Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.

import getopt, sys

from seppl_common import *
import xml.sax, xml.sax.handler

name = None
algorithm = None
bits = 0
reverse = 0
PROC_FILE_NAME = "/proc/net/seppl_keyring"
file = None

class KeyContentHandler(xml.sax.handler.ContentHandler):

	last = None

	def startElement(self, name, attrs):
		self.last = name
		
		if name != "key":
			return
		
		self.name = ""
		self.algorithm = ""
		self.bits = ""
		self.data = ""

	def endElement(self, n):
		global name, algorithm, bits
		self.last = None
		
		if n != "key":
			return

		if self.name == "":
			self.name = "def"

		if self.algorithm == "":
			self.algorithm = "aes"

		if self.bits == "":
			self.bits = 128
		else:
			self.bits = int(self.bits)
		
		a = find_alg_by_name(self.algorithm, self.bits)
		if a == -1:
			raise xml.sax.SAXNotRecognizedException("Cipher not known")

		key = parse_key(self.data)
		if key is None or len(key) != self.bits/8:
			raise xml.sax.SAXNotRecognizedException("Could not parse key data.")

		if (name is None or name == self.name) and (algorithm is None or algorithm == self.algorithm) and (bits == 0 or bits == self.bits):
			dump_key_bin(a, self.name, key)

	def characters(self, content):
		content = content.strip()

		if len(content) == 0:
			return
		
		if self.last == "name":
			self.name += content
			return
		if self.last == "algorithm":
			self.algorithm += content
			return
		if self.last == "bits":
			self.bits += content
			return
		if self.last == "data":
			self.data += content
			return

		raise xml.sax.SAXNotRecognizedException("Malformed XML structure |%s|%s|" % (self.last, content))

def usage():
	global name, algorithm, bits, reverse, file
	
	print "%s:" % sys.argv[0]
	print "   -h --help                   Show this help"
	print "   -r --reverse                Convert XML to binary, instead of the other way round (%s)" % { 0 : "disabled", 1 : "enabled" }[reverse]
	print "   -a --algorithm ALGORITHM    Show only keys with  algorithm (%s)" % algorithm
	print "   -b --bits BITS              Show only keys with bit length (%s)" % bits
	print "   -n --name NAME              Show only keys with name (%s)" % name
	print "   -f --file FILE              Specify file (- for STDIN) (%s)" % file
	pass

def main():
	global name, algorithm, bits, reverse, file
	
	try:	
		opts, args = getopt.getopt(sys.argv[1:], "hn:a:b:rf:", ["help", "name=", "algorithm=", "bits=", "reverse", "file"])
	except getopt.GetoptError:
		usage()
		sys.exit(2)

	u = 0
	
	for o, a in opts:
		if o in ("-h", "--help"):
			u = 1
			
		if o in ("-n", "--name"):
			name = a[:7]

		if o in ("-a", "--algorithm"):
			algorithm = a

		if o in ("-b", "--bits"):
			bits = int(a)

		if o in ("-r", "--reverse"):
			reverse = 1

		if o in ("-f", "--file"):
			file = a

	if file is None:
		if reverse:
			file = "-"
		else:
			file = PROC_FILE_NAME

	if u:
		usage()
		sys.exit(0)


	if file == "-":
		buf = sys.stdin.read();
	else:
		try:
			fd = open(file, "r+")
			buf = fd.read();
			fd.close()
		except IOError, e:
			sys.stderr.write("Could not open proc-file (%s).\n" % str(e))
			sys.exit(2)


	if len(buf) == 0:
		sys.exit(0)

	if buf[0] == '<':
		reverse = 1

	if not reverse:

		print "<seppl-keyring>"
		while len(buf) >= 8:
			a, _name = unpack("B7s", buf[:8])
			n, b = find_alg_by_number(a)
			
			if (b == 0):
				sys.stderr.write("ERROR: Unknown cipher. Please update.\n")
				break

			_name = _name.replace("\000", "")

			if (name is None or name == _name) and (algorithm is None or algorithm == n) and (bits == 0 or b == bits):
				dump_key_xml(a, _name, buf[8:b/8+8])

			buf = buf[8+b/8:]
		print "</seppl-keyring>"
	else:
		try:
			xml.sax.parseString(buf, KeyContentHandler())
		except xml.sax.SAXException, e:
			sys.stderr.write("Parse error (%s)\n" %str(e))

	
if __name__ == "__main__":
	main()