internals: document CBOR utilization
I spoke with some people at Mozilla about CBOR and they advised me
that we should be careful about the subset of CBOR we use in order
to mitigate security, performance, and compatibility concerns.
This commit establishes a document that attempts to formalize our
use of CBOR.
Its main limitations are on what types are allowed. It explicitly
enumerates which types are supported. Notable missing features
include:
* Indefinite-length arrays and maps
* Text strings (bytes all the way)
* Floats
* Date/time types
* Big integers
* Use of indefinite-length byte strings for map keys, values in
containers.
If we have a need for any of these, we can have a discussion about
them when the time comes.
Differential Revision: https://phab.mercurial-scm.org/D4412
# Since it's not easy to write a test that portably deals
# with files from different users/groups, we cheat a bit by
# monkey-patching some functions in the util module
from __future__ import absolute_import, print_function
import os
from mercurial import (
error,
ui as uimod,
util,
)
hgrc = os.environ['HGRCPATH']
f = open(hgrc)
basehgrc = f.read()
f.close()
def testui(user='foo', group='bar', tusers=(), tgroups=(),
cuser='foo', cgroup='bar', debug=False, silent=False,
report=True):
# user, group => owners of the file
# tusers, tgroups => trusted users/groups
# cuser, cgroup => user/group of the current process
# write a global hgrc with the list of trusted users/groups and
# some setting so that we can be sure it was read
f = open(hgrc, 'w')
f.write(basehgrc)
f.write('\n[paths]\n')
f.write('global = /some/path\n\n')
if tusers or tgroups:
f.write('[trusted]\n')
if tusers:
f.write('users = %s\n' % ', '.join(tusers))
if tgroups:
f.write('groups = %s\n' % ', '.join(tgroups))
f.close()
# override the functions that give names to uids and gids
def username(uid=None):
if uid is None:
return cuser
return user
util.username = username
def groupname(gid=None):
if gid is None:
return 'bar'
return group
util.groupname = groupname
def isowner(st):
return user == cuser
util.isowner = isowner
# try to read everything
#print '# File belongs to user %s, group %s' % (user, group)
#print '# trusted users = %s; trusted groups = %s' % (tusers, tgroups)
kind = ('different', 'same')
who = ('', 'user', 'group', 'user and the group')
trusted = who[(user in tusers) + 2*(group in tgroups)]
if trusted:
trusted = ', but we trust the ' + trusted
print('# %s user, %s group%s' % (kind[user == cuser], kind[group == cgroup],
trusted))
u = uimod.ui.load()
# disable the configuration registration warning
#
# the purpose of this test is to check the old behavior, not to validate the
# behavior from registered item. so we silent warning related to unregisted
# config.
u.setconfig('devel', 'warn-config-unknown', False, 'test')
u.setconfig('devel', 'all-warnings', False, 'test')
u.setconfig('ui', 'debug', str(bool(debug)))
u.setconfig('ui', 'report_untrusted', str(bool(report)))
u.readconfig('.hg/hgrc')
if silent:
return u
print('trusted')
for name, path in u.configitems('paths'):
print(' ', name, '=', util.pconvert(path))
print('untrusted')
for name, path in u.configitems('paths', untrusted=True):
print('.', end=' ')
u.config('paths', name) # warning with debug=True
print('.', end=' ')
u.config('paths', name, untrusted=True) # no warnings
print(name, '=', util.pconvert(path))
print()
return u
os.mkdir('repo')
os.chdir('repo')
os.mkdir('.hg')
f = open('.hg/hgrc', 'w')
f.write('[paths]\n')
f.write('local = /another/path\n\n')
f.close()
#print '# Everything is run by user foo, group bar\n'
# same user, same group
testui()
# same user, different group
testui(group='def')
# different user, same group
testui(user='abc')
# ... but we trust the group
testui(user='abc', tgroups=['bar'])
# different user, different group
testui(user='abc', group='def')
# ... but we trust the user
testui(user='abc', group='def', tusers=['abc'])
# ... but we trust the group
testui(user='abc', group='def', tgroups=['def'])
# ... but we trust the user and the group
testui(user='abc', group='def', tusers=['abc'], tgroups=['def'])
# ... but we trust all users
print('# we trust all users')
testui(user='abc', group='def', tusers=['*'])
# ... but we trust all groups
print('# we trust all groups')
testui(user='abc', group='def', tgroups=['*'])
# ... but we trust the whole universe
print('# we trust all users and groups')
testui(user='abc', group='def', tusers=['*'], tgroups=['*'])
# ... check that users and groups are in different namespaces
print("# we don't get confused by users and groups with the same name")
testui(user='abc', group='def', tusers=['def'], tgroups=['abc'])
# ... lists of user names work
print("# list of user names")
testui(user='abc', group='def', tusers=['foo', 'xyz', 'abc', 'bleh'],
tgroups=['bar', 'baz', 'qux'])
# ... lists of group names work
print("# list of group names")
testui(user='abc', group='def', tusers=['foo', 'xyz', 'bleh'],
tgroups=['bar', 'def', 'baz', 'qux'])
print("# Can't figure out the name of the user running this process")
testui(user='abc', group='def', cuser=None)
print("# prints debug warnings")
u = testui(user='abc', group='def', cuser='foo', debug=True)
print("# report_untrusted enabled without debug hides warnings")
u = testui(user='abc', group='def', cuser='foo', report=False)
print("# report_untrusted enabled with debug shows warnings")
u = testui(user='abc', group='def', cuser='foo', debug=True, report=False)
print("# ui.readconfig sections")
filename = 'foobar'
f = open(filename, 'w')
f.write('[foobar]\n')
f.write('baz = quux\n')
f.close()
u.readconfig(filename, sections=['foobar'])
print(u.config('foobar', 'baz'))
print()
print("# read trusted, untrusted, new ui, trusted")
u = uimod.ui.load()
# disable the configuration registration warning
#
# the purpose of this test is to check the old behavior, not to validate the
# behavior from registered item. so we silent warning related to unregisted
# config.
u.setconfig('devel', 'warn-config-unknown', False, 'test')
u.setconfig('devel', 'all-warnings', False, 'test')
u.setconfig('ui', 'debug', 'on')
u.readconfig(filename)
u2 = u.copy()
def username(uid=None):
return 'foo'
util.username = username
u2.readconfig('.hg/hgrc')
print('trusted:')
print(u2.config('foobar', 'baz'))
print('untrusted:')
print(u2.config('foobar', 'baz', untrusted=True))
print()
print("# error handling")
def assertraises(f, exc=error.Abort):
try:
f()
except exc as inst:
print('raised', inst.__class__.__name__)
else:
print('no exception?!')
print("# file doesn't exist")
os.unlink('.hg/hgrc')
assert not os.path.exists('.hg/hgrc')
testui(debug=True, silent=True)
testui(user='abc', group='def', debug=True, silent=True)
print()
print("# parse error")
f = open('.hg/hgrc', 'w')
f.write('foo')
f.close()
try:
testui(user='abc', group='def', silent=True)
except error.ParseError as inst:
print(inst)
try:
testui(debug=True, silent=True)
except error.ParseError as inst:
print(inst)
print()
print('# access typed information')
with open('.hg/hgrc', 'w') as f:
f.write('''\
[foo]
sub=main
sub:one=one
sub:two=two
path=monty/python
bool=true
int=42
bytes=81mb
list=spam,ham,eggs
''')
u = testui(user='abc', group='def', cuser='foo', silent=True)
def configpath(section, name, default=None, untrusted=False):
path = u.configpath(section, name, default, untrusted)
if path is None:
return None
return util.pconvert(path)
print('# suboptions, trusted and untrusted')
trusted = u.configsuboptions('foo', 'sub')
untrusted = u.configsuboptions('foo', 'sub', untrusted=True)
print(
(trusted[0], sorted(trusted[1].items())),
(untrusted[0], sorted(untrusted[1].items())))
print('# path, trusted and untrusted')
print(configpath('foo', 'path'), configpath('foo', 'path', untrusted=True))
print('# bool, trusted and untrusted')
print(u.configbool('foo', 'bool'), u.configbool('foo', 'bool', untrusted=True))
print('# int, trusted and untrusted')
print(
u.configint('foo', 'int', 0),
u.configint('foo', 'int', 0, untrusted=True))
print('# bytes, trusted and untrusted')
print(
u.configbytes('foo', 'bytes', 0),
u.configbytes('foo', 'bytes', 0, untrusted=True))
print('# list, trusted and untrusted')
print(
u.configlist('foo', 'list', []),
u.configlist('foo', 'list', [], untrusted=True))