smtp: verify the certificate of the SMTP server for STARTTLS/SMTPS
Before this patch, the certificate of the SMTP server for STARTTLS or
SMTPS isn't verified.
This may cause man-in-the-middle security problem (stealing
authentication information), even though SMTP channel itself is
encrypted by SSL.
When "[smtp] tls" is configured as "smtps" or "starttls", this patch:
- uses classes introduced by preceding patches instead of "SMTP" or
"SMTP_SSL" of smtplib, and
- verifies the certificate of the SMTP server, if "[smtp]
verifycert" is configured as other than False
"[smtp] verifycert" can be configured in 3 levels:
- "strict":
This verifies peer certificate, and aborts if:
- peer certification is not valid, or
- no configuration in "[hostfingerprints]" and "[web] cacerts"
This is default value of "[smtp] verifycert" for security.
- "loose":
This verifies peer certificate, and aborts if peer certification is
not valid.
This just shows warning message ("certificate not verified"), if
there is no configuration in "[hostfingerprints]" and "[web]
cacerts".
This is as same as verification for HTTPS connection.
- False(no verification):
Peer certificate is not verified.
This is as same as the behavior before this patch series.
"hg email --insecure" uses "loose" level, and ignores "[web] cacerts"
as same as push/pull/etc... with --insecure.
Ignoring "[web] cacerts" configuration for "hg email --insecure" is
already done in "dispatch._dispatch()" by looking "insecure" up in the
table of command options.
$ "$TESTDIR/hghave" pyflakes || exit 80
$ cd "`dirname "$TESTDIR"`"
$ pyflakes mercurial hgext 2>&1 | "$TESTDIR/filterpyflakes.py"
hgext/inotify/linux/__init__.py:*: 'from _inotify import *' used; unable to detect undefined names (glob)