# Mercurial and safely storing passwords

Mercurial allows for tying in keyring configuration for those of us who do not want to store passwords in plain-text in our .hgrc files or constantly using SSH.

First install the Python keyring library by running pip install keyring. After that is installed, checkout https://bitbucket.org/Mekk/mercurial_keyring/ and add to $HOME/.hgrc the following:  [extensions] mercurial_keyring = ~/path/to/mercurial_keyring/mercurial_keyring.py Next up, configure your repositories, e.g. in the case of Bitbucket I use:  [auth] bitbucket.prefix = bitbucket.org/asmodai bitbucket.username = asmodai bitbucket.schemes = https Mercurial keyring will automatically decide on the best keyring to use. On a FreeBSD system with no Gnome or other systems providing a keyring, if you do not specify a specific keyring, the system will use the file ~/.local/share/python_keyring/keyring_pass.cfg. This keyring file stores the passwords encoded in Base64 in plain-text. This is not quite what you would want from a security point of view. You can configure which backend store to use by editing$HOME/.local/share/python-keyring/keyringrc.cfg. To get a plain-text file with encrypted keys use the following configuration:

 [backend] default-keyring=keyring.backend.CryptedFileKeyring

This will create the file ~/.local/share/python-keyring/crypted_pass.cfg after initializing the backend store with a password. Look at the documentation for keyring on what other configuration options are available.

Note: make sure the PyCrypto dependency is installed with the _fastmath module. This in turn depends on the gmp library.

# Separating multiple SVN projects into individual Hg repositories

If you have a Subversion repository setup with multiple top-level projects and their typical  branches/tags/trunk setup and want to migrate these to individual Mercurial (Hg) repositories, you can do this with the convert extension.

First you need to enable convert in your .hgrc by adding a section like the following:

 [extensions] convert =

Next, if needed, create a plain-text file, e.g. author-map.txt, containing SVN username to Hg author mappings, e.g. asmodai=Jeroen Ruigrok van der Werven <email@address.tld>.

Next run Hg as follows:

hg --authors author-map.txt --config convert.svn.branches=project/branches --config convert.svn.tags=project/tags --config convert.svn.trunk=project/trunk path/to/svn/repository path/to/destination/hg/repository

This will start a SVN to Hg conversion, picking up only the changes and commit messages applicable for the various paths you gave for the branches, tags, and trunk, effectively splitting off this project from the main SVN tree into its own Hg repository.

Do note that for large SVN repositories this might not be the most efficient conversion way forward. In that case converting once from SVN to Hg and then split off Hg into many Hg repositories might be faster. Will adjust this post when I write that up.

# TortoiseHG and wildcard certificates

Having resolved recent SSL certificate issues with Mercurial/TortoiseHG, I now encountered a similar issue with the wildcard certificate for *.google.com where getting a clone would result in a "SSL: Server certificate verify failed" error.

One way around this issue is to add the fingerprint for this certificate to your configuration. Currently for *.google.com this is 00:d5:88:35:29:b9:7f:03:92:60:c2:04:e4:b7:01:f0:07:53:15:a8 and one way to get this from a Unix command line is with openssl s_client -connect code.google.com:443 < /dev/null 2> /dev/null | openssl x509 -in cert-code -fingerprint -noout -in /dev/stdin | tr "[:upper:]" "[:lower:]". This corresponds with Chrome’s certificate view’s thumbprint field, you just need to add colons.

Right click in Explorer, select TortoiseHG » Global Settings and then click Edit File and add the following:

[hostfingerprints]

This should make Mercurial/TortoiseHG work, at least until the certificate expires and you need to update it with the latest fingerprint.

# TortoiseHG and non-standard SSL certificates

For my own development I use Mercurial and TortoiseHG for my version control system. I also use, at the moment, a CAcert certificate to use HTTPS with my repositories. I am not sure what changed when, but apparently the certificates now get verified. So this causes obvious problems trying to push or pull due to "SSL: Server certificate verify failed" errors.

To make this work on a Windows 7 machine with TortoiseHG in stalled, first download the CAcert root PEM certificate and place it some permanent directory. Next open the TortoiseHG global settings (right click somewhere in Explorer and select TortoiseHG » Global Settings). In the window that opens click the Edit File button. If it does not exist yet create a section similar to this:

[web]
cacerts = C:\path\to\cacert-root.pem

Press Save and OK and any push and pull action with HTTPS URLs should work as they ought to.

# Mercurial 1.7, cacerts, and FreeBSD

So with recent Mercurial 1.7 releases HTTPS support was tightened, so you are bound to encounter a warning in the form of: warning: bitbucket.org certificate not verified (check web.cacerts config setting).

Now, on http://mercurial.selenic.com/wiki/CACertificates there are details on what to configure for certain operating systems. Given I use FreeBSD, I altered my \$HOME/.hgrc as follows:

[code]
[web]
cacerts = /etc/ssl/cert.pem
[/code]

For OpenBSD this should be in the same place since release 3.8. But apparently NetBSD does not have such a file in base.

# svn switch in Mercurial (hg)

For my own sanity:

In order to change the parent repository URL of a Mercurial clone (as svn switch does) one simply edits .hg/hgrc and adjusts the default under [paths].