pull: add tests for unsafe ssh url (SEC)

clone: add tests for unsafe ssh url (SEC)

sshpeer: check for safe ssh url (SEC) Checking in the sshpeer for a rogue ssh:// urls seems like the right place to do it (instead of whack-a-mole with pull, clone, push, etc).

ssh: ban any username@host or host that starts with - (SEC) This paranoia probably isn't required, but it can't hurt either.

util: add utility method to check for bad ssh urls (SEC) Our use of SSH has an exploit that will parse the first part of an url blindly as a hostname. Prior to this set of security patches, a url with '-oProxyCommand' could run arbitrary code on a user's machine. In addition, at least on Windows, a pipe '|' can be abused to execute arbitrary commands in a similar fashion. We defend against this by checking ssh:// URLs and looking for a hostname that starts with a - or contains a |. When this happens, let's throw a big abort into the user's face so that they can inspect what's going on.

pathauditor: disable cache of audited paths by default (issue5628) The initial attempt was to discard cache when appropriate, but it appears to be error prone. We had to carefully inspect all places where audit() is called e.g. without actually updating filesystem, before removing files and directories, etc. So, this patch disables the cache of audited paths by default, and enables it only for the following cases: - short-lived auditor objects - repo.vfs, repo.svfs, and repo.cachevfs, which are managed directories and considered sort of append-only (a file/directory would never be replaced with a symlink) There would be more cacheable vfs objects (e.g. mq.queue.opener), but I decided not to inspect all of them in this patch. We can make them cached later. Benchmark result: - using old clone of http://selenic.com/repo/linux-2.6/ (38319 files) - on tmpfs - run HGRCPATH=/dev/null hg up -q --time tip && hg up -q null - try 4 times and take the last three results original: real 7.480 secs (user 1.140+22.760 sys 0.150+1.690) real 8.010 secs (user 1.070+22.280 sys 0.170+2.120) real 7.470 secs (user 1.120+22.390 sys 0.120+1.910) clearcache (the other series): real 7.680 secs (user 1.120+23.420 sys 0.140+1.970) real 7.670 secs (user 1.110+23.620 sys 0.130+1.810) real 7.740 secs (user 1.090+23.510 sys 0.160+1.940) enable cache only for vfs and svfs (this series): real 8.730 secs (user 1.500+25.190 sys 0.260+2.260) real 8.750 secs (user 1.490+25.170 sys 0.250+2.340) real 9.010 secs (user 1.680+25.340 sys 0.280+2.540) remove cache function at all (for reference): real 9.620 secs (user 1.440+27.120 sys 0.250+2.980) real 9.420 secs (user 1.400+26.940 sys 0.320+3.130) real 9.760 secs (user 1.530+27.270 sys 0.250+2.970)

tests: show cache of audited paths is never invalidated

stable: merge heads

Added signature for changeset 943c91326b23

Added tag 4.2.3 for changeset 943c91326b23