tests/test-patchbomb-tls.t

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.

[e-mail] provided some extra fixes for the dispatch code and
for hg-ssh in places that I overlooked.

#require serve ssl

Set up SMTP server:

  $ CERTSDIR="$TESTDIR/sslcerts"
  $ cat "$CERTSDIR/priv.pem" "$CERTSDIR/pub.pem" >> server.pem

  $ python "$TESTDIR/dummysmtpd.py" -p $HGPORT --pid-file a.pid -d \
  > --tls smtps --certificate `pwd`/server.pem
  listening at localhost:$HGPORT
  $ cat a.pid >> $DAEMON_PIDS

Ensure hg email output is sent to stdout:

  $ unset PAGER

Set up repository:

  $ hg init t
  $ cd t
  $ cat <<EOF >> .hg/hgrc
  > [extensions]
  > patchbomb =
  > [email]
  > method = smtp
  > [smtp]
  > host = localhost
  > port = $HGPORT
  > tls = smtps
  > EOF

  $ echo a > a
  $ hg commit -Ama -d '1 0'
  adding a

Utility functions:

  $ DISABLECACERTS=
  $ try () {
  >   hg email $DISABLECACERTS -f quux -t foo -c bar -r tip "$@"
  > }

Our test cert is not signed by a trusted CA. It should fail to verify if
we are able to load CA certs:

#if sslcontext defaultcacerts no-defaultcacertsloaded
  $ try
  this patch series consists of 1 patches.
  
  
  (an attempt was made to load CA certificates but none were loaded; see https://mercurial-scm.org/wiki/SecureConnections for how to configure Mercurial to avoid this error)
  (?i)abort: .*?certificate.verify.failed.* (re)
  [255]
#endif

#if no-sslcontext defaultcacerts
  $ try
  this patch series consists of 1 patches.
  
  
  warning: connecting to localhost using legacy security technology (TLS 1.0); see https://mercurial-scm.org/wiki/SecureConnections for more info
  (using CA certificates from *; if you see this message, your Mercurial install is not properly configured; see https://mercurial-scm.org/wiki/SecureConnections for how to configure Mercurial to avoid this message) (glob) (?)
  (?i)abort: .*?certificate.verify.failed.* (re)
  [255]
#endif

#if defaultcacertsloaded
  $ try
  this patch series consists of 1 patches.
  
  
  warning: connecting to localhost using legacy security technology (TLS 1.0); see https://mercurial-scm.org/wiki/SecureConnections for more info (?)
  (using CA certificates from *; if you see this message, your Mercurial install is not properly configured; see https://mercurial-scm.org/wiki/SecureConnections for how to configure Mercurial to avoid this message) (glob) (?)
  (?i)abort: .*?certificate.verify.failed.* (re)
  [255]

#endif

#if no-defaultcacerts
  $ try
  this patch series consists of 1 patches.
  
  
  (unable to load * certificates; see https://mercurial-scm.org/wiki/SecureConnections for how to configure Mercurial to avoid this message) (glob) (?)
  abort: localhost certificate error: no certificate received
  (set hostsecurity.localhost:certfingerprints=sha256:62:09:97:2f:97:60:e3:65:8f:12:5d:78:9e:35:a1:36:7a:65:4b:0e:9f:ac:db:c3:bc:6e:b6:a3:c0:16:e0:30 config setting or use --insecure to connect insecurely)
  [255]
#endif

  $ DISABLECACERTS="--config devel.disableloaddefaultcerts=true"

Without certificates:

  $ try --debug
  this patch series consists of 1 patches.
  
  
  (using smtps)
  sending mail: smtp host localhost, port * (glob)
  warning: connecting to localhost using legacy security technology (TLS 1.0); see https://mercurial-scm.org/wiki/SecureConnections for more info (?)
  (verifying remote certificate)
  abort: unable to verify security of localhost (no loaded CA certificates); refusing to connect
  (see https://mercurial-scm.org/wiki/SecureConnections for how to configure Mercurial to avoid this error or set hostsecurity.localhost:fingerprints=sha256:20:de:b3:ad:b4:cd:a5:42:f0:74:41:1c:a2:70:1e:da:6e:c0:5c:16:9e:e7:22:0f:f1:b7:e5:6e:e4:92:af:7e to trust this server)
  [255]

With global certificates:

  $ try --debug --config web.cacerts="$CERTSDIR/pub.pem"
  this patch series consists of 1 patches.
  
  
  (using smtps)
  sending mail: smtp host localhost, port * (glob)
  warning: connecting to localhost using legacy security technology (TLS 1.0); see https://mercurial-scm.org/wiki/SecureConnections for more info (?)
  (verifying remote certificate)
  sending [PATCH] a ...

With invalid certificates:

  $ try --config web.cacerts="$CERTSDIR/pub-other.pem"
  this patch series consists of 1 patches.
  
  
  warning: connecting to localhost using legacy security technology (TLS 1.0); see https://mercurial-scm.org/wiki/SecureConnections for more info (?)
  (?i)abort: .*?certificate.verify.failed.* (re)
  [255]

  $ cd ..