tests/test-patchbomb-tls.t

sslutil: emit warning when no CA certificates loaded

If no CA certificates are loaded, that is almost certainly a/the
reason certificate verification fails when connecting to a server.

The modern ssl module in Python 2.7.9+ provides an API to access
the list of loaded CA certificates. This patch emits a warning
on modern Python when certificate verification fails and there are
no loaded CA certificates.

There is no way to detect the number of loaded CA certificates
unless the modern ssl module is present. Hence the differences
in test output depending on whether modern ssl is available.

It's worth noting that a test which specifies a CA file still
renders this warning. That is because the certificate it is loading
is a x509 client certificate and not a CA certificate. This
test could be updated if anyone is so inclined.

#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 defaultcacerts
  $ 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

  $ 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)
  (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=sha256:62:09:97:2f: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 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)
  (verifying remote certificate)
  sending [PATCH] a ...

With invalid certificates:

  $ try --config web.cacerts="$CERTSDIR/pub-other.pem"
  this patch series consists of 1 patches.
  
  
  (?i)abort: .*?certificate.verify.failed.* (re)
  [255]

  $ cd ..