#! @PYTHON@
-# -*-python-*-
-
-### External dependencies
+### -*-python-*-
+###
+### Key management and distribution
+###
+### (c) 2006 Straylight/Edgeware
+###
+
+###----- Licensing notice ---------------------------------------------------
+###
+### This file is part of Trivial IP Encryption (TrIPE).
+###
+### TrIPE 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.
+###
+### TrIPE 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 TrIPE; if not, write to the Free Software Foundation,
+### Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+
+###--------------------------------------------------------------------------
+### External dependencies.
import catacomb as C
import os as OS
import sys as SYS
-import sre as RX
+import re as RX
import getopt as O
import shutil as SH
+import time as T
import filecmp as FC
from cStringIO import StringIO
from errno import *
from stat import *
+###--------------------------------------------------------------------------
### Useful regular expressions
+## Match a comment or blank line.
rx_comment = RX.compile(r'^\s*(#|$)')
+
+## Match a KEY = VALUE assignment.
rx_keyval = RX.compile(r'^\s*([-\w]+)(?:\s+(?!=)|\s*=\s*)(|\S|\S.*\S)\s*$')
+
+## Match a ${KEY} substitution.
rx_dollarsubst = RX.compile(r'\$\{([-\w]+)\}')
+
+## Match a @TAG@ substitution.
rx_atsubst = RX.compile(r'@([-\w]+)@')
+
+## Match a single non-alphanumeric character.
rx_nonalpha = RX.compile(r'\W')
+
+## Match the literal string "<SEQ>".
rx_seq = RX.compile(r'\<SEQ\>')
-### Utility functions
+## Match a shell metacharacter.
+rx_shmeta = RX.compile('[\\s`!"#$&*()\\[\\];\'|<>?\\\\]')
+## Match a character which needs escaping in a shell double-quoted string.
+rx_shquote = RX.compile(r'["`$\\]')
+
+###--------------------------------------------------------------------------
+### Utility functions.
+
+## Exceptions.
class SubprocessError (Exception): pass
class VerifyError (Exception): pass
+## Program name and identification.
quis = OS.path.basename(SYS.argv[0])
PACKAGE = "@PACKAGE@"
VERSION = "@VERSION@"
def moan(msg):
+ """Report MSG to standard error."""
SYS.stderr.write('%s: %s\n' % (quis, msg))
def die(msg, rc = 1):
+ """Report MSG to standard error, and exit with code RC."""
moan(msg)
SYS.exit(rc)
def subst(s, rx, map):
+ """
+ Substitute values into a string.
+
+ Repeatedly match RX (a compiled regular expression) against the string S.
+ For each match, extract group 1, and use it as a key to index the MAP;
+ replace the match by the result. Finally, return the fully-substituted
+ string.
+ """
out = StringIO()
i = 0
for m in rx.finditer(s):
out.write(s[i:])
return out.getvalue()
+def shell_quotify(arg):
+ """
+ Quotify ARG to keep the shell happy.
+
+ This isn't actually used for invoking commands, just for presentation
+ purposes; but correctness is still nice.
+ """
+ if not rx_shmeta.search(arg):
+ return arg
+ elif arg.find("'") == -1:
+ return "'%s'" % arg
+ else:
+ return '"%s"' % rx_shquote.sub(lambda m: '\\' + m.group(0), arg)
+
def rmtree(path):
+ """Delete the directory tree given by PATH."""
try:
st = OS.lstat(path)
except OSError, err:
OS.rmdir(path)
def zap(file):
+ """Delete the named FILE if it exists; otherwise do nothing."""
try:
OS.unlink(file)
except OSError, err:
raise
def run(args):
+ """
+ Run a subprocess whose arguments are given by the string ARGS.
+
+ The ARGS are split at word boundaries, and then subjected to configuration
+ variable substitution (see conf_subst). Individual argument elements
+ beginning with `!' are split again into multiple arguments at word
+ boundaries.
+ """
args = map(conf_subst, args.split())
nargs = []
for a in args:
else:
nargs += a[1:].split()
args = nargs
- print '+ %s' % ' '.join(args)
+ print '+ %s' % ' '.join([shell_quotify(arg) for arg in args])
+ SYS.stdout.flush()
rc = OS.spawnvp(OS.P_WAIT, args[0], args)
if rc != 0:
raise SubprocessError, rc
def hexhyphens(bytes):
+ """
+ Convert a byte string BYTES into hex, with hyphens at each 4-byte boundary.
+ """
out = StringIO()
for i in xrange(0, len(bytes)):
if i > 0 and i % 4 == 0: out.write('-')
return out.getvalue()
def fingerprint(kf, ktag):
+ """
+ Compute the fingerprint of a key, using the user's selected hash.
+
+ KF is the name of a keyfile; KTAG is the tag of the key.
+ """
h = C.gchashes[conf['fingerprint-hash']]()
k = C.KeyFile(kf)[ktag].fingerprint(h, '-secret')
return h.done()
-### Read configuration
+###--------------------------------------------------------------------------
+### The configuration file.
+## Exceptions.
class ConfigFileError (Exception): pass
+
+## The configuration dictionary.
conf = {}
-def conf_subst(s): return subst(s, rx_dollarsubst, conf)
+def conf_subst(s):
+ """
+ Apply configuration substitutions to S.
+
+ That is, for each ${KEY} in S, replace it with the current value of the
+ configuration variable KEY.
+ """
+ return subst(s, rx_dollarsubst, conf)
-## Read the file
def conf_read(f):
+ """
+ Read the file F and insert assignments into the configuration dictionary.
+ """
lno = 0
for line in file(f):
lno += 1
k, v = match.groups()
conf[k] = conf_subst(v)
-## Sift the wreckage
def conf_defaults():
+ """
+ Apply defaults to the configuration dictionary.
+
+ Fill in all the interesting configuration variables based on the existing
+ contents, as described in the manual.
+ """
for k, v in [('repos-base', 'tripe-keys.tar.gz'),
('sig-base', 'tripe-keys.sig-<SEQ>'),
('repos-url', '${base-url}${repos-base}'),
('conf-file', '${base-dir}tripe-keys.conf'),
('upload-hook', ': run upload hook'),
('kx', 'dh'),
- ('kx-param', lambda: {'dh': '-LS -b2048 -B256',
+ ('kx-param', lambda: {'dh': '-LS -b3072 -B256',
'ec': '-Cnist-p256'}[conf['kx']]),
('kx-expire', 'now + 1 year'),
- ('cipher', 'blowfish-cbc'),
+ ('kx-warn-days', '28'),
+ ('cipher', 'rijndael-cbc'),
('hash', 'sha256'),
+ ('master-keygen-flags', '-l'),
('mgf', '${hash}-mgf'),
('mac', lambda: '%s-hmac/%d' %
(conf['hash'],
'rsapss': 'rsa',
'ecdsa': 'ec',
'eckcdsa': 'ec'}[conf['sig']]),
- ('sig-param', lambda: {'dh': '-LS -b2048 -B256',
- 'dsa': '-b2048 -B256',
+ ('sig-param', lambda: {'dh': '-LS -b3072 -B256',
+ 'dsa': '-b3072 -B256',
'ec': '-Cnist-p256',
- 'rsa': '-b2048'}[conf['sig-genalg']]),
+ 'rsa': '-b3072'}[conf['sig-genalg']]),
('sig-hash', '${hash}'),
('sig-expire', 'forever'),
('fingerprint-hash', '${hash}')]:
if len(exc.args) == 0: raise
conf[k] = '<missing-var %s>' % exc.args[0]
-### Commands
+###--------------------------------------------------------------------------
+### Key-management utilities.
+
+def master_keys():
+ """
+ Iterate over the master keys.
+ """
+ if not OS.path.exists('master'):
+ return
+ for k in C.KeyFile('master').itervalues():
+ if (k.type != 'tripe-keys-master' or
+ k.expiredp or
+ not k.tag.startswith('master-')):
+ continue #??
+ yield k
+
+def master_sequence(k):
+ """
+ Return the sequence number of the given master key as an integer.
+
+ No checking is done that K is really a master key.
+ """
+ return int(k.tag[7:])
+
+def max_master_sequence():
+ """
+ Find the master key with the highest sequence number and return this
+ sequence number.
+ """
+ seq = -1
+ for k in master_keys():
+ q = master_sequence(k)
+ if q > seq: seq = q
+ return seq
+
+def seqsubst(x, q):
+ """
+ Return the value of the configuration variable X, with <SEQ> replaced by
+ the value Q.
+ """
+ return rx_seq.sub(str(q), conf[x])
+
+###--------------------------------------------------------------------------
+### Commands: help [COMMAND...]
def version(fp = SYS.stdout):
fp.write('%s, %s version %s\n' % (quis, PACKAGE, VERSION))
args = commands.keys()
args.sort()
for c in args:
- func, min, max, help = commands[c]
- print '%s %s' % (c, help)
+ try: func, min, max, help = commands[c]
+ except KeyError: die("unknown command `%s'" % c)
+ print '%s%s%s' % (c, help and ' ', help)
-def master_keys():
- if not OS.path.exists('master'):
- return
- for k in C.KeyFile('master').itervalues():
- if (k.type != 'tripe-keys-master' or
- k.expiredp or
- not k.tag.startswith('master-')):
- continue #??
- yield k
-def master_sequence(k):
- return int(k.tag[7:])
-def max_master_sequence():
- seq = -1
- for k in master_keys():
- q = master_sequence(k)
- if q > seq: seq = q
- return seq
-def seqsubst(x, q):
- return rx_seq.sub(str(q), conf[x])
+###--------------------------------------------------------------------------
+### Commands: newmaster
def cmd_newmaster(args):
seq = max_master_sequence() + 1
run('''key -kmaster add
-a${sig-genalg} !${sig-param}
- -e${sig-expire} -l -tmaster-%d tripe-keys-master
+ -e${sig-expire} !${master-keygen-flags} -tmaster-%d tripe-keys-master
sig=${sig} hash=${sig-hash}''' % seq)
run('key -kmaster extract -f-secret repos/master.pub')
+###--------------------------------------------------------------------------
+### Commands: setup
+
def cmd_setup(args):
OS.mkdir('repos')
run('''key -krepos/param add
-a${kx}-param !${kx-param}
- -eforever -tparam tripe-${kx}-param
- cipher=${cipher} hash=${hash} mac=${mac} mgf=${mgf}''')
+ -eforever -tparam tripe-param
+ kx-group=${kx} cipher=${cipher} hash=${hash} mac=${mac} mgf=${mgf}''')
cmd_newmaster(args)
+###--------------------------------------------------------------------------
+### Commands: upload
+
def cmd_upload(args):
## Sanitize the repository directory
rmtree('tmp')
run('sh -c ${upload-hook}')
+###--------------------------------------------------------------------------
+### Commands: rebuild
+
+def cmd_rebuild(args):
+ zap('keyring.pub')
+ for i in OS.listdir('repos'):
+ if i.startswith('peer-') and i.endswith('.pub'):
+ run('key -kkeyring.pub merge %s' % OS.path.join('repos', i))
+
+###--------------------------------------------------------------------------
+### Commands: update
+
def cmd_update(args):
cwd = OS.getcwd()
rmtree('tmp')
OS.chdir(cwd)
if OS.path.exists('repos'): OS.rename('repos', 'repos.old')
OS.rename('tmp/repos', 'repos')
- if not FC.cmp('tmp/tripe-keys.conf', 'tripe-keys.conf'):
+ if not FC.cmp('tmp/tripe-keys.conf', 'tripe-keys.conf', False):
moan('configuration file changed: recommend running another update')
OS.rename('tmp/tripe-keys.conf', 'tripe-keys.conf')
rmtree('repos.old')
rmtree('tmp')
cmd_rebuild(args)
-def cmd_rebuild(args):
- zap('keyring.pub')
- for i in OS.listdir('repos'):
- if i.startswith('peer-') and i.endswith('.pub'):
- run('key -kkeyring.pub merge %s' % OS.path.join('repos', i))
+###--------------------------------------------------------------------------
+### Commands: generate TAG
def cmd_generate(args):
tag, = args
keyring_pub = 'peer-%s.pub' % tag
zap('keyring'); zap(keyring_pub)
run('key -kkeyring merge repos/param')
- run('key -kkeyring add -a${kx} -pparam -e${kx-expire} -t%s tripe-${kx}' %
+ run('key -kkeyring add -a${kx} -pparam -e${kx-expire} -t%s tripe' %
tag)
run('key -kkeyring extract -f-secret %s %s' % (keyring_pub, tag))
+###--------------------------------------------------------------------------
+### Commands: clean
+
def cmd_clean(args):
rmtree('repos')
rmtree('tmp')
r == 'keyring' or r == 'keyring.pub' or r.startswith('peer-')):
zap(i)
-### Main driver
+###--------------------------------------------------------------------------
+### Commands: check
+
+def check_key(k):
+ now = T.time()
+ thresh = int(conf['kx-warn-days']) * 86400
+ if k.exptime == C.KEXP_FOREVER: return None
+ elif k.exptime == C.KEXP_EXPIRE: left = -1
+ else: left = k.exptime - now
+ if left < 0:
+ return "key `%s' HAS EXPIRED" % k.tag
+ elif left < thresh:
+ if left >= 86400: n, u, uu = left // 86400, 'day', 'days'
+ else: n, u, uu = left // 3600, 'hour', 'hours'
+ return "key `%s' EXPIRES in %d %s" % (k.tag, n, n == 1 and u or uu)
+ else:
+ return None
+
+def cmd_check(args):
+ if OS.path.exists('keyring.pub'):
+ for k in C.KeyFile('keyring.pub').itervalues():
+ whinge = check_key(k)
+ if whinge is not None: print whinge
+ if OS.path.exists('master'):
+ whinges = []
+ for k in C.KeyFile('master').itervalues():
+ whinge = check_key(k)
+ if whinge is None: break
+ whinges.append(whinge)
+ else:
+ for whinge in whinges: print whinge
+
+###--------------------------------------------------------------------------
+### Commands: mtu
+
+def cmd_mtu(args):
+ mtu, = (lambda mtu = '1500': (mtu,))(*args)
+ mtu = int(mtu)
+
+ blksz = C.gcciphers[conf['cipher']].blksz
+
+ index = conf['mac'].find('/')
+ if index == -1:
+ tagsz = C.gcmacs[conf['mac']].tagsz
+ else:
+ tagsz = int(conf['mac'][index + 1:])/8
+
+ mtu -= 20 # Minimum IP header
+ mtu -= 8 # UDP header
+ mtu -= 1 # TrIPE packet type octet
+ mtu -= tagsz # MAC tag
+ mtu -= 4 # Sequence number
+ mtu -= blksz # Initialization vector
+
+ print mtu
-class UsageError (Exception): pass
+###--------------------------------------------------------------------------
+### Main driver.
commands = {'help': (cmd_help, 0, 1, ''),
'newmaster': (cmd_newmaster, 0, 0, ''),
'upload': (cmd_upload, 0, 0, ''),
'update': (cmd_update, 0, 0, ''),
'clean': (cmd_clean, 0, 0, ''),
+ 'mtu': (cmd_mtu, 0, 1, '[PATH-MTU]'),
+ 'check': (cmd_check, 0, 0, ''),
'generate': (cmd_generate, 1, 1, 'TAG'),
'rebuild': (cmd_rebuild, 0, 0, '')}
def init():
+ """
+ Load the appropriate configuration file and set up the configuration
+ dictionary.
+ """
for f in ['tripe-keys.master', 'tripe-keys.conf']:
if OS.path.exists(f):
conf_read(f)
break
conf_defaults()
+
def main(argv):
+ """
+ Main program: parse options and dispatch to appropriate command handler.
+ """
try:
opts, args = O.getopt(argv[1:], 'hvu',
['help', 'version', 'usage'])
cmd_help([])
else:
c = argv[1]
- func, min, max, help = commands[c]
+ try: func, min, max, help = commands[c]
+ except KeyError: die("unknown command `%s'" % c)
args = argv[2:]
- if len(args) < min or (max > 0 and len(args) > max):
- raise UsageError, (c, help)
+ if len(args) < min or (max is not None and len(args) > max):
+ SYS.stderr.write('Usage: %s %s%s%s\n' % (quis, c, help and ' ', help))
+ SYS.exit(1)
func(args)
-init()
-main(SYS.argv)
+###----- That's all, folks --------------------------------------------------
+
+if __name__ == '__main__':
+ init()
+ main(SYS.argv)