view mercurial/node.py @ 28525:dfb21c34e07d

sslutil: allow multiple fingerprints per host

Certificate pinning via [hostfingerprints] is a useful security
feature. Currently, we only support one fingerprint per hostname.
This is simple but it fails in the real world:

* Switching certificates breaks clients until they change the
  pinned certificate fingerprint. This incurs client downtime
  and can require massive amounts of coordination to perform
  certificate changes.
* Some servers operate with multiple certificates on the same
  hostname.

This patch adds support for defining multiple certificate
fingerprints per host. This overcomes the deficiencies listed
above. I anticipate the primary use case of this feature will
be to define both the old and new certificate so a certificate
transition can occur with minimal interruption, so this scenario
has been called out in the help documentation.

# 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.

from __future__ import absolute_import

import binascii

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

nullrev = -1
nullid = "\0" * 20
nullhex = hex(nullid)

# pseudo identifiers for working directory
# (they are experimental, so don't add too many dependencies on them)
wdirrev = 0x7fffffff
wdirid = "\xff" * 20

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