view tests/test-url.py @ 46607:e9901d01d135

revlog: add a mechanism to verify expected file position before appending

If someone uses `hg debuglocks`, or some non-hg process writes to the .hg
directory without respecting the locks, or if the repo's on a networked
filesystem, it's possible for the revlog code to write out corrupted data.

The form of this corruption can vary depending on what data was written and how
that happened. We are in the "networked filesystem" case (though I've had users
also do this to themselves with the "`hg debuglocks`" scenario), and most often
see this with the changelog. What ends up happening is we produce two items
(let's call them rev1 and rev2) in the .i file that have the same linkrev,
baserev, and offset into the .d file, while the data in the .d file is appended
properly. rev2's compressed_size is accurate for rev2, but when we go to
decompress the data in the .d file, we use the offset that's recorded in the
index file, which is the same as rev1, and attempt to decompress
rev2.compressed_size bytes of rev1's data. This usually does not succeed. :)

When using inline data, this also fails, though I haven't investigated why too
closely. This shows up as a "patch decode" error. I believe what's happening
there is that we're basically ignoring the offset field, getting the data
properly, but since baserev != rev, it thinks this is a delta based on rev
(instead of a full text) and can't actually apply it as such.

For now, I'm going to make this an optional component and default it to entirely
off. I may increase the default severity of this in the future, once I've
enabled it for my users and we gain more experience with it. Luckily, most of my
users have a versioned filesystem and can roll back to before the corruption has
been written, it's just a hassle to do so and not everyone knows how (so it's a
support burden). Users on other filesystems will not have that luxury, and this
can cause them to have a corrupted repository that they are unlikely to know how
to resolve, and they'll see this as a data-loss event. Refusing to create the
corruption is a much better user experience.

This mechanism is not perfect. There may be false-negatives (racy writes that
are not detected). There should not be any false-positives (non-racy writes that
are detected as such). This is not a mechanism that makes putting a repo on a
networked filesystem "safe" or "supported", just *less* likely to cause
corruption.

Differential Revision: https://phab.mercurial-scm.org/D9952

# coding=utf-8
from __future__ import absolute_import, print_function

import doctest
import os


def check(a, b):
    if a != b:
        print((a, b))


def cert(cn):
    return {'subject': ((('commonName', cn),),)}


from mercurial import sslutil

_verifycert = sslutil._verifycert
# Test non-wildcard certificates
check(_verifycert(cert('example.com'), 'example.com'), None)
check(
    _verifycert(cert('example.com'), 'www.example.com'),
    b'certificate is for example.com',
)
check(
    _verifycert(cert('www.example.com'), 'example.com'),
    b'certificate is for www.example.com',
)

# Test wildcard certificates
check(_verifycert(cert('*.example.com'), 'www.example.com'), None)
check(
    _verifycert(cert('*.example.com'), 'example.com'),
    b'certificate is for *.example.com',
)
check(
    _verifycert(cert('*.example.com'), 'w.w.example.com'),
    b'certificate is for *.example.com',
)

# Test subjectAltName
san_cert = {
    'subject': ((('commonName', 'example.com'),),),
    'subjectAltName': (('DNS', '*.example.net'), ('DNS', 'example.net')),
}
check(_verifycert(san_cert, 'example.net'), None)
check(_verifycert(san_cert, 'foo.example.net'), None)
# no fallback to subject commonName when subjectAltName has DNS
check(
    _verifycert(san_cert, 'example.com'),
    b'certificate is for *.example.net, example.net',
)
# fallback to subject commonName when no DNS in subjectAltName
san_cert = {
    'subject': ((('commonName', 'example.com'),),),
    'subjectAltName': (('IP Address', '8.8.8.8'),),
}
check(_verifycert(san_cert, 'example.com'), None)

# Avoid some pitfalls
check(_verifycert(cert('*.foo'), 'foo'), b'certificate is for *.foo')
check(_verifycert(cert('*o'), 'foo'), None)

check(
    _verifycert({'subject': ()}, 'example.com'),
    b'no commonName or subjectAltName found in certificate',
)
check(_verifycert(None, 'example.com'), b'no certificate received')

# Unicode (IDN) certname isn't supported
check(
    _verifycert(cert(u'\u4f8b.jp'), 'example.jp'),
    b'IDN in certificate not supported',
)

# The following tests are from CPython's test_ssl.py.
check(_verifycert(cert('example.com'), 'example.com'), None)
check(_verifycert(cert('example.com'), 'ExAmple.cOm'), None)
check(
    _verifycert(cert('example.com'), 'www.example.com'),
    b'certificate is for example.com',
)
check(
    _verifycert(cert('example.com'), '.example.com'),
    b'certificate is for example.com',
)
check(
    _verifycert(cert('example.com'), 'example.org'),
    b'certificate is for example.com',
)
check(
    _verifycert(cert('example.com'), 'exampleXcom'),
    b'certificate is for example.com',
)
check(_verifycert(cert('*.a.com'), 'foo.a.com'), None)
check(
    _verifycert(cert('*.a.com'), 'bar.foo.a.com'), b'certificate is for *.a.com'
)
check(_verifycert(cert('*.a.com'), 'a.com'), b'certificate is for *.a.com')
check(_verifycert(cert('*.a.com'), 'Xa.com'), b'certificate is for *.a.com')
check(_verifycert(cert('*.a.com'), '.a.com'), b'certificate is for *.a.com')

# only match one left-most wildcard
check(_verifycert(cert('f*.com'), 'foo.com'), None)
check(_verifycert(cert('f*.com'), 'f.com'), None)
check(_verifycert(cert('f*.com'), 'bar.com'), b'certificate is for f*.com')
check(_verifycert(cert('f*.com'), 'foo.a.com'), b'certificate is for f*.com')
check(_verifycert(cert('f*.com'), 'bar.foo.com'), b'certificate is for f*.com')

# NULL bytes are bad, CVE-2013-4073
check(
    _verifycert(
        cert('null.python.org\x00example.org'), 'null.python.org\x00example.org'
    ),
    None,
)
check(
    _verifycert(cert('null.python.org\x00example.org'), 'example.org'),
    b'certificate is for null.python.org\x00example.org',
)
check(
    _verifycert(cert('null.python.org\x00example.org'), 'null.python.org'),
    b'certificate is for null.python.org\x00example.org',
)

# error cases with wildcards
check(
    _verifycert(cert('*.*.a.com'), 'bar.foo.a.com'),
    b'certificate is for *.*.a.com',
)
check(_verifycert(cert('*.*.a.com'), 'a.com'), b'certificate is for *.*.a.com')
check(_verifycert(cert('*.*.a.com'), 'Xa.com'), b'certificate is for *.*.a.com')
check(_verifycert(cert('*.*.a.com'), '.a.com'), b'certificate is for *.*.a.com')

check(_verifycert(cert('a.*.com'), 'a.foo.com'), b'certificate is for a.*.com')
check(_verifycert(cert('a.*.com'), 'a..com'), b'certificate is for a.*.com')
check(_verifycert(cert('a.*.com'), 'a.com'), b'certificate is for a.*.com')

# wildcard doesn't match IDNA prefix 'xn--'
idna = u'püthon.python.org'.encode('idna').decode('ascii')
check(_verifycert(cert(idna), idna), None)
check(
    _verifycert(cert('x*.python.org'), idna),
    b'certificate is for x*.python.org',
)
check(
    _verifycert(cert('xn--p*.python.org'), idna),
    b'certificate is for xn--p*.python.org',
)

# wildcard in first fragment and  IDNA A-labels in sequent fragments
# are supported.
idna = u'www*.pythön.org'.encode('idna').decode('ascii')
check(
    _verifycert(cert(idna), u'www.pythön.org'.encode('idna').decode('ascii')),
    None,
)
check(
    _verifycert(cert(idna), u'www1.pythön.org'.encode('idna').decode('ascii')),
    None,
)
check(
    _verifycert(cert(idna), u'ftp.pythön.org'.encode('idna').decode('ascii')),
    b'certificate is for www*.xn--pythn-mua.org',
)
check(
    _verifycert(cert(idna), u'pythön.org'.encode('idna').decode('ascii')),
    b'certificate is for www*.xn--pythn-mua.org',
)

c = {
    'notAfter': 'Jun 26 21:41:46 2011 GMT',
    'subject': (((u'commonName', u'linuxfrz.org'),),),
    'subjectAltName': (
        ('DNS', 'linuxfr.org'),
        ('DNS', 'linuxfr.com'),
        ('othername', '<unsupported>'),
    ),
}
check(_verifycert(c, 'linuxfr.org'), None)
check(_verifycert(c, 'linuxfr.com'), None)
# Not a "DNS" entry
check(
    _verifycert(c, '<unsupported>'),
    b'certificate is for linuxfr.org, linuxfr.com',
)
# When there is a subjectAltName, commonName isn't used
check(
    _verifycert(c, 'linuxfrz.org'),
    b'certificate is for linuxfr.org, linuxfr.com',
)

# A pristine real-world example
c = {
    'notAfter': 'Dec 18 23:59:59 2011 GMT',
    'subject': (
        ((u'countryName', u'US'),),
        ((u'stateOrProvinceName', u'California'),),
        ((u'localityName', u'Mountain View'),),
        ((u'organizationName', u'Google Inc'),),
        ((u'commonName', u'mail.google.com'),),
    ),
}
check(_verifycert(c, 'mail.google.com'), None)
check(_verifycert(c, 'gmail.com'), b'certificate is for mail.google.com')

# Only commonName is considered
check(_verifycert(c, 'California'), b'certificate is for mail.google.com')

# Neither commonName nor subjectAltName
c = {
    'notAfter': 'Dec 18 23:59:59 2011 GMT',
    'subject': (
        ((u'countryName', u'US'),),
        ((u'stateOrProvinceName', u'California'),),
        ((u'localityName', u'Mountain View'),),
        ((u'organizationName', u'Google Inc'),),
    ),
}
check(
    _verifycert(c, 'mail.google.com'),
    b'no commonName or subjectAltName found in certificate',
)

# No DNS entry in subjectAltName but a commonName
c = {
    'notAfter': 'Dec 18 23:59:59 2099 GMT',
    'subject': (
        ((u'countryName', u'US'),),
        ((u'stateOrProvinceName', u'California'),),
        ((u'localityName', u'Mountain View'),),
        ((u'commonName', u'mail.google.com'),),
    ),
    'subjectAltName': (('othername', 'blabla'),),
}
check(_verifycert(c, 'mail.google.com'), None)

# No DNS entry subjectAltName and no commonName
c = {
    'notAfter': 'Dec 18 23:59:59 2099 GMT',
    'subject': (
        ((u'countryName', u'US'),),
        ((u'stateOrProvinceName', u'California'),),
        ((u'localityName', u'Mountain View'),),
        ((u'organizationName', u'Google Inc'),),
    ),
    'subjectAltName': (('othername', 'blabla'),),
}
check(
    _verifycert(c, 'google.com'),
    b'no commonName or subjectAltName found in certificate',
)

# Empty cert / no cert
check(_verifycert(None, 'example.com'), b'no certificate received')
check(_verifycert({}, 'example.com'), b'no certificate received')

# avoid denials of service by refusing more than one
# wildcard per fragment.
check(
    _verifycert({'subject': (((u'commonName', u'a*b.com'),),)}, 'axxb.com'),
    None,
)
check(
    _verifycert({'subject': (((u'commonName', u'a*b.co*'),),)}, 'axxb.com'),
    b'certificate is for a*b.co*',
)
check(
    _verifycert({'subject': (((u'commonName', u'a*b*.com'),),)}, 'axxbxxc.com'),
    b'too many wildcards in certificate DNS name: a*b*.com',
)


def test_url():
    """
    >>> from mercurial import error, pycompat
    >>> from mercurial.util import url
    >>> from mercurial.utils.stringutil import forcebytestr

    This tests for edge cases in url.URL's parsing algorithm. Most of
    these aren't useful for documentation purposes, so they aren't
    part of the class's doc tests.

    Query strings and fragments:

    >>> url(b'http://host/a?b#c')
    <url scheme: 'http', host: 'host', path: 'a', query: 'b', fragment: 'c'>
    >>> url(b'http://host/a?')
    <url scheme: 'http', host: 'host', path: 'a'>
    >>> url(b'http://host/a#b#c')
    <url scheme: 'http', host: 'host', path: 'a', fragment: 'b#c'>
    >>> url(b'http://host/a#b?c')
    <url scheme: 'http', host: 'host', path: 'a', fragment: 'b?c'>
    >>> url(b'http://host/?a#b')
    <url scheme: 'http', host: 'host', path: '', query: 'a', fragment: 'b'>
    >>> url(b'http://host/?a#b', parsequery=False)
    <url scheme: 'http', host: 'host', path: '?a', fragment: 'b'>
    >>> url(b'http://host/?a#b', parsefragment=False)
    <url scheme: 'http', host: 'host', path: '', query: 'a#b'>
    >>> url(b'http://host/?a#b', parsequery=False, parsefragment=False)
    <url scheme: 'http', host: 'host', path: '?a#b'>

    IPv6 addresses:

    >>> url(b'ldap://[2001:db8::7]/c=GB?objectClass?one')
    <url scheme: 'ldap', host: '[2001:db8::7]', path: 'c=GB',
         query: 'objectClass?one'>
    >>> url(b'ldap://joe:xxx@[2001:db8::7]:80/c=GB?objectClass?one')
    <url scheme: 'ldap', user: 'joe', passwd: 'xxx', host: '[2001:db8::7]',
         port: '80', path: 'c=GB', query: 'objectClass?one'>

    Missing scheme, host, etc.:

    >>> url(b'://192.0.2.16:80/')
    <url path: '://192.0.2.16:80/'>
    >>> url(b'https://mercurial-scm.org')
    <url scheme: 'https', host: 'mercurial-scm.org'>
    >>> url(b'/foo')
    <url path: '/foo'>
    >>> url(b'bundle:/foo')
    <url scheme: 'bundle', path: '/foo'>
    >>> url(b'a?b#c')
    <url path: 'a?b', fragment: 'c'>
    >>> url(b'http://x.com?arg=/foo')
    <url scheme: 'http', host: 'x.com', query: 'arg=/foo'>
    >>> url(b'http://joe:xxx@/foo')
    <url scheme: 'http', user: 'joe', passwd: 'xxx', path: 'foo'>

    Just a scheme and a path:

    >>> url(b'mailto:[e-mail]')
    <url scheme: 'mailto', path: '[e-mail]'>
    >>> url(b'a:b:c:d')
    <url path: 'a:b:c:d'>
    >>> url(b'aa:bb:cc:dd')
    <url scheme: 'aa', path: 'bb:cc:dd'>

    SSH examples:

    >>> url(b'ssh://joe@host//home/joe')
    <url scheme: 'ssh', user: 'joe', host: 'host', path: '/home/joe'>
    >>> url(b'ssh://joe:xxx@host/src')
    <url scheme: 'ssh', user: 'joe', passwd: 'xxx', host: 'host', path: 'src'>
    >>> url(b'ssh://joe:xxx@host')
    <url scheme: 'ssh', user: 'joe', passwd: 'xxx', host: 'host'>
    >>> url(b'ssh://joe@host')
    <url scheme: 'ssh', user: 'joe', host: 'host'>
    >>> url(b'ssh://host')
    <url scheme: 'ssh', host: 'host'>
    >>> url(b'ssh://')
    <url scheme: 'ssh'>
    >>> url(b'ssh:')
    <url scheme: 'ssh'>

    Non-numeric port:

    >>> url(b'http://example.com:dd')
    <url scheme: 'http', host: 'example.com', port: 'dd'>
    >>> url(b'ssh://joe:xxx@host:ssh/foo')
    <url scheme: 'ssh', user: 'joe', passwd: 'xxx', host: 'host', port: 'ssh',
         path: 'foo'>

    Bad authentication credentials:

    >>> url(b'http://joe@joeville:123@4:@host/a?b#c')
    <url scheme: 'http', user: 'joe@joeville', passwd: '123@4:',
         host: 'host', path: 'a', query: 'b', fragment: 'c'>
    >>> url(b'http://!*#?/@!*#?/:@host/a?b#c')
    <url scheme: 'http', host: '!*', fragment: '?/@!*#?/:@host/a?b#c'>
    >>> url(b'http://!*#?@!*#?:@host/a?b#c')
    <url scheme: 'http', host: '!*', fragment: '?@!*#?:@host/a?b#c'>
    >>> url(b'http://!*@:!*@@host/a?b#c')
    <url scheme: 'http', user: '!*@', passwd: '!*@', host: 'host',
         path: 'a', query: 'b', fragment: 'c'>

    File paths:

    >>> url(b'a/b/c/d.g.f')
    <url path: 'a/b/c/d.g.f'>
    >>> url(b'/x///z/y/')
    <url path: '/x///z/y/'>
    >>> url(b'/foo:bar')
    <url path: '/foo:bar'>
    >>> url(b'\\\\foo:bar')
    <url path: '\\\\foo:bar'>
    >>> url(b'./foo:bar')
    <url path: './foo:bar'>

    Non-localhost file URL:

    >>> try:
    ...   u = url(b'file://mercurial-scm.org/foo')
    ... except error.Abort as e:
    ...   pycompat.bytestr(e.message)
    'file:// URLs can only refer to localhost'

    Empty URL:

    >>> u = url(b'')
    >>> u
    <url path: ''>
    >>> str(u)
    ''

    Empty path with query string:

    >>> str(url(b'http://foo/?bar'))
    'http://foo/?bar'

    Invalid path:

    >>> u = url(b'http://foo/bar')
    >>> u.path = b'bar'
    >>> str(u)
    'http://foo/bar'

    >>> u = url(b'file:/foo/bar/baz')
    >>> u
    <url scheme: 'file', path: '/foo/bar/baz'>
    >>> str(u)
    'file:///foo/bar/baz'
    >>> pycompat.bytestr(u.localpath())
    '/foo/bar/baz'

    >>> u = url(b'file:///foo/bar/baz')
    >>> u
    <url scheme: 'file', path: '/foo/bar/baz'>
    >>> str(u)
    'file:///foo/bar/baz'
    >>> pycompat.bytestr(u.localpath())
    '/foo/bar/baz'

    >>> u = url(b'file:///f:oo/bar/baz')
    >>> u
    <url scheme: 'file', path: 'f:oo/bar/baz'>
    >>> str(u)
    'file:///f:oo/bar/baz'
    >>> pycompat.bytestr(u.localpath())
    'f:oo/bar/baz'

    >>> u = url(b'file://localhost/f:oo/bar/baz')
    >>> u
    <url scheme: 'file', host: 'localhost', path: 'f:oo/bar/baz'>
    >>> str(u)
    'file://localhost/f:oo/bar/baz'
    >>> pycompat.bytestr(u.localpath())
    'f:oo/bar/baz'

    >>> u = url(b'file:foo/bar/baz')
    >>> u
    <url scheme: 'file', path: 'foo/bar/baz'>
    >>> str(u)
    'file:foo/bar/baz'
    >>> pycompat.bytestr(u.localpath())
    'foo/bar/baz'
    """


if 'TERM' in os.environ:
    del os.environ['TERM']

doctest.testmod(optionflags=doctest.NORMALIZE_WHITESPACE)