view mercurial/node.py @ 18888:19d489404d79

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.

# node.py - basic nodeid manipulation for mercurial
#
# Copyright 2005, 2006 Matt Mackall <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

import binascii

nullrev = -1
nullid = "\0" * 20

# This ugly style has a noticeable effect in manifest parsing
hex = binascii.hexlify
bin = binascii.unhexlify

def short(node):
    return hex(node[:6])