Mercurial > hg
view mercurial/filelog.py @ 32050:77eaf9539499 stable 4.1.3
dispatch: protect against malicious 'hg serve --stdio' invocations (sec)
Some shared-ssh installations assume that 'hg serve --stdio' is a safe
command to run for minimally trusted users. Unfortunately, the messy
implementation of argument parsing here meant that trying to access a
repo named '--debugger' would give the user a pdb prompt, thereby
sidestepping any hoped-for sandboxing. Serving repositories over HTTP(S)
is unaffected.
We're not currently hardening any subcommands other than 'serve'. If
your service exposes other commands to users with arbitrary repository
names, it is imperative that you defend against repository names of
'--debugger' and anything starting with '--config'.
The read-only mode of hg-ssh stopped working because it provided its hook
configuration to "hg serve --stdio" via --config parameter. This is banned for
security reasons now. This patch switches it to directly call ui.setconfig().
If your custom hosting infrastructure relies on passing --config to
"hg serve --stdio", you'll need to find a different way to get that configuration
into Mercurial, either by using ui.setconfig() as hg-ssh does in this patch,
or by placing an hgrc file someplace where Mercurial will read it.
mitrandir@fb.com provided some extra fixes for the dispatch code and
for hg-ssh in places that I overlooked.
author | Augie Fackler <augie@google.com> |
---|---|
date | Wed, 12 Apr 2017 11:23:55 -0700 |
parents | be5b2098a817 |
children | 8ac7ac714e92 |
line wrap: on
line source
# filelog.py - file history class for mercurial # # Copyright 2005-2007 Matt Mackall <mpm@selenic.com> # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. from __future__ import absolute_import import re import struct from . import ( error, mdiff, revlog, ) _mdre = re.compile('\1\n') def parsemeta(text): """return (metadatadict, keylist, metadatasize)""" # text can be buffer, so we can't use .startswith or .index if text[:2] != '\1\n': return None, None s = _mdre.search(text, 2).start() mtext = text[2:s] meta = {} for l in mtext.splitlines(): k, v = l.split(": ", 1) meta[k] = v return meta, (s + 2) def packmeta(meta, text): keys = sorted(meta.iterkeys()) metatext = "".join("%s: %s\n" % (k, meta[k]) for k in keys) return "\1\n%s\1\n%s" % (metatext, text) def _censoredtext(text): m, offs = parsemeta(text) return m and "censored" in m class filelog(revlog.revlog): def __init__(self, opener, path): super(filelog, self).__init__(opener, "/".join(("data", path + ".i"))) def read(self, node): t = self.revision(node) if not t.startswith('\1\n'): return t s = t.index('\1\n', 2) return t[s + 2:] def add(self, text, meta, transaction, link, p1=None, p2=None): if meta or text.startswith('\1\n'): text = packmeta(meta, text) return self.addrevision(text, transaction, link, p1, p2) def renamed(self, node): if self.parents(node)[0] != revlog.nullid: return False t = self.revision(node) m = parsemeta(t)[0] if m and "copy" in m: return (m["copy"], revlog.bin(m["copyrev"])) return False def size(self, rev): """return the size of a given revision""" # for revisions with renames, we have to go the slow way node = self.node(rev) if self.renamed(node): return len(self.read(node)) if self.iscensored(rev): return 0 # XXX if self.read(node).startswith("\1\n"), this returns (size+4) return super(filelog, self).size(rev) def cmp(self, node, text): """compare text with a given file revision returns True if text is different than what is stored. """ t = text if text.startswith('\1\n'): t = '\1\n\1\n' + text samehashes = not super(filelog, self).cmp(node, t) if samehashes: return False # censored files compare against the empty file if self.iscensored(self.rev(node)): return text != '' # renaming a file produces a different hash, even if the data # remains unchanged. Check if it's the case (slow): if self.renamed(node): t2 = self.read(node) return t2 != text return True def checkhash(self, text, node, p1=None, p2=None, rev=None): try: super(filelog, self).checkhash(text, node, p1=p1, p2=p2, rev=rev) except error.RevlogError: if _censoredtext(text): raise error.CensoredNodeError(self.indexfile, node, text) raise def iscensored(self, rev): """Check if a file revision is censored.""" return self.flags(rev) & revlog.REVIDX_ISCENSORED def _peek_iscensored(self, baserev, delta, flush): """Quickly check if a delta produces a censored revision.""" # Fragile heuristic: unless new file meta keys are added alphabetically # preceding "censored", all censored revisions are prefixed by # "\1\ncensored:". A delta producing such a censored revision must be a # full-replacement delta, so we inspect the first and only patch in the # delta for this prefix. hlen = struct.calcsize(">lll") if len(delta) <= hlen: return False oldlen = self.rawsize(baserev) newlen = len(delta) - hlen if delta[:hlen] != mdiff.replacediffheader(oldlen, newlen): return False add = "\1\ncensored:" addlen = len(add) return newlen >= addlen and delta[hlen:hlen + addlen] == add