tests: fix toctou race in tinyproxy.py (
issue3795)
test-http-proxy.t sometimes failed with:
File ".../tests/tinyproxy.py", line 110, in _read_write
data = i.recv(8192)
error: (104, 'Connection reset by peer')
This might have started showing up with
a9fd11ffa13f ... but it has apparently
also been seen before. I don't see anything in
a9fd11ffa13f that can explain
it. It seems to be a race in test, in the tinyproxy helper:
Tinyproxy found an incoming socket using select(). It would break the loop if
an error had been detected on the socket, but there was no error and it tried
to recv() from the socket. That failed - apparently because it had been reset
after select().
Errors in the recv() will now be caught and will break the loop like errors
detected by select() would.
(send() could also fail in a similar way ... but using the same solution there
and losing data we have read doesn't feel right.)
# Copyright 2005, 2006 Benoit Boissinot <benoit.boissinot@ens-lyon.org>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
'''commands to sign and verify changesets'''
import os, tempfile, binascii
from mercurial import util, commands, match, cmdutil
from mercurial import node as hgnode
from mercurial.i18n import _
cmdtable = {}
command = cmdutil.command(cmdtable)
testedwith = 'internal'
class gpg(object):
def __init__(self, path, key=None):
self.path = path
self.key = (key and " --local-user \"%s\"" % key) or ""
def sign(self, data):
gpgcmd = "%s --sign --detach-sign%s" % (self.path, self.key)
return util.filter(data, gpgcmd)
def verify(self, data, sig):
""" returns of the good and bad signatures"""
sigfile = datafile = None
try:
# create temporary files
fd, sigfile = tempfile.mkstemp(prefix="hg-gpg-", suffix=".sig")
fp = os.fdopen(fd, 'wb')
fp.write(sig)
fp.close()
fd, datafile = tempfile.mkstemp(prefix="hg-gpg-", suffix=".txt")
fp = os.fdopen(fd, 'wb')
fp.write(data)
fp.close()
gpgcmd = ("%s --logger-fd 1 --status-fd 1 --verify "
"\"%s\" \"%s\"" % (self.path, sigfile, datafile))
ret = util.filter("", gpgcmd)
finally:
for f in (sigfile, datafile):
try:
if f:
os.unlink(f)
except OSError:
pass
keys = []
key, fingerprint = None, None
err = ""
for l in ret.splitlines():
# see DETAILS in the gnupg documentation
# filter the logger output
if not l.startswith("[GNUPG:]"):
continue
l = l[9:]
if l.startswith("ERRSIG"):
err = _("error while verifying signature")
break
elif l.startswith("VALIDSIG"):
# fingerprint of the primary key
fingerprint = l.split()[10]
elif (l.startswith("GOODSIG") or
l.startswith("EXPSIG") or
l.startswith("EXPKEYSIG") or
l.startswith("BADSIG")):
if key is not None:
keys.append(key + [fingerprint])
key = l.split(" ", 2)
fingerprint = None
if err:
return err, []
if key is not None:
keys.append(key + [fingerprint])
return err, keys
def newgpg(ui, **opts):
"""create a new gpg instance"""
gpgpath = ui.config("gpg", "cmd", "gpg")
gpgkey = opts.get('key')
if not gpgkey:
gpgkey = ui.config("gpg", "key", None)
return gpg(gpgpath, gpgkey)
def sigwalk(repo):
"""
walk over every sigs, yields a couple
((node, version, sig), (filename, linenumber))
"""
def parsefile(fileiter, context):
ln = 1
for l in fileiter:
if not l:
continue
yield (l.split(" ", 2), (context, ln))
ln += 1
# read the heads
fl = repo.file(".hgsigs")
for r in reversed(fl.heads()):
fn = ".hgsigs|%s" % hgnode.short(r)
for item in parsefile(fl.read(r).splitlines(), fn):
yield item
try:
# read local signatures
fn = "localsigs"
for item in parsefile(repo.opener(fn), fn):
yield item
except IOError:
pass
def getkeys(ui, repo, mygpg, sigdata, context):
"""get the keys who signed a data"""
fn, ln = context
node, version, sig = sigdata
prefix = "%s:%d" % (fn, ln)
node = hgnode.bin(node)
data = node2txt(repo, node, version)
sig = binascii.a2b_base64(sig)
err, keys = mygpg.verify(data, sig)
if err:
ui.warn("%s:%d %s\n" % (fn, ln , err))
return None
validkeys = []
# warn for expired key and/or sigs
for key in keys:
if key[0] == "BADSIG":
ui.write(_("%s Bad signature from \"%s\"\n") % (prefix, key[2]))
continue
if key[0] == "EXPSIG":
ui.write(_("%s Note: Signature has expired"
" (signed by: \"%s\")\n") % (prefix, key[2]))
elif key[0] == "EXPKEYSIG":
ui.write(_("%s Note: This key has expired"
" (signed by: \"%s\")\n") % (prefix, key[2]))
validkeys.append((key[1], key[2], key[3]))
return validkeys
@command("sigs", [], _('hg sigs'))
def sigs(ui, repo):
"""list signed changesets"""
mygpg = newgpg(ui)
revs = {}
for data, context in sigwalk(repo):
node, version, sig = data
fn, ln = context
try:
n = repo.lookup(node)
except KeyError:
ui.warn(_("%s:%d node does not exist\n") % (fn, ln))
continue
r = repo.changelog.rev(n)
keys = getkeys(ui, repo, mygpg, data, context)
if not keys:
continue
revs.setdefault(r, [])
revs[r].extend(keys)
for rev in sorted(revs, reverse=True):
for k in revs[rev]:
r = "%5d:%s" % (rev, hgnode.hex(repo.changelog.node(rev)))
ui.write("%-30s %s\n" % (keystr(ui, k), r))
@command("sigcheck", [], _('hg sigcheck REV'))
def check(ui, repo, rev):
"""verify all the signatures there may be for a particular revision"""
mygpg = newgpg(ui)
rev = repo.lookup(rev)
hexrev = hgnode.hex(rev)
keys = []
for data, context in sigwalk(repo):
node, version, sig = data
if node == hexrev:
k = getkeys(ui, repo, mygpg, data, context)
if k:
keys.extend(k)
if not keys:
ui.write(_("no valid signature for %s\n") % hgnode.short(rev))
return
# print summary
ui.write("%s is signed by:\n" % hgnode.short(rev))
for key in keys:
ui.write(" %s\n" % keystr(ui, key))
def keystr(ui, key):
"""associate a string to a key (username, comment)"""
keyid, user, fingerprint = key
comment = ui.config("gpg", fingerprint, None)
if comment:
return "%s (%s)" % (user, comment)
else:
return user
@command("sign",
[('l', 'local', None, _('make the signature local')),
('f', 'force', None, _('sign even if the sigfile is modified')),
('', 'no-commit', None, _('do not commit the sigfile after signing')),
('k', 'key', '',
_('the key id to sign with'), _('ID')),
('m', 'message', '',
_('commit message'), _('TEXT')),
] + commands.commitopts2,
_('hg sign [OPTION]... [REV]...'))
def sign(ui, repo, *revs, **opts):
"""add a signature for the current or given revision
If no revision is given, the parent of the working directory is used,
or tip if no revision is checked out.
See :hg:`help dates` for a list of formats valid for -d/--date.
"""
mygpg = newgpg(ui, **opts)
sigver = "0"
sigmessage = ""
date = opts.get('date')
if date:
opts['date'] = util.parsedate(date)
if revs:
nodes = [repo.lookup(n) for n in revs]
else:
nodes = [node for node in repo.dirstate.parents()
if node != hgnode.nullid]
if len(nodes) > 1:
raise util.Abort(_('uncommitted merge - please provide a '
'specific revision'))
if not nodes:
nodes = [repo.changelog.tip()]
for n in nodes:
hexnode = hgnode.hex(n)
ui.write(_("signing %d:%s\n") % (repo.changelog.rev(n),
hgnode.short(n)))
# build data
data = node2txt(repo, n, sigver)
sig = mygpg.sign(data)
if not sig:
raise util.Abort(_("error while signing"))
sig = binascii.b2a_base64(sig)
sig = sig.replace("\n", "")
sigmessage += "%s %s %s\n" % (hexnode, sigver, sig)
# write it
if opts['local']:
repo.opener.append("localsigs", sigmessage)
return
msigs = match.exact(repo.root, '', ['.hgsigs'])
s = repo.status(match=msigs, unknown=True, ignored=True)[:6]
if util.any(s) and not opts["force"]:
raise util.Abort(_("working copy of .hgsigs is changed "
"(please commit .hgsigs manually "
"or use --force)"))
sigsfile = repo.wfile(".hgsigs", "ab")
sigsfile.write(sigmessage)
sigsfile.close()
if '.hgsigs' not in repo.dirstate:
repo[None].add([".hgsigs"])
if opts["no_commit"]:
return
message = opts['message']
if not message:
# we don't translate commit messages
message = "\n".join(["Added signature for changeset %s"
% hgnode.short(n)
for n in nodes])
try:
repo.commit(message, opts['user'], opts['date'], match=msigs)
except ValueError, inst:
raise util.Abort(str(inst))
def node2txt(repo, node, ver):
"""map a manifest into some text"""
if ver == "0":
return "%s\n" % hgnode.hex(node)
else:
raise util.Abort(_("unknown signature version"))