Re: Wildcards in mailmap to hide transgender people's deadnames

["Florine W. Dekker" <florine@fwdekker.com>]

On 14/09/2022 09:40, René Scharfe wrote:
> Am 13.09.22 um 23:53 schrieb Florine W. Dekker:
>> Now, John can now add the following line to their mailmap config:
>> `John Doe <john.doe@example.com> <\*.doe@example.com>`, which does
>> not reveal their old name.
> That would falsely attribute the work of possible future developers
> ann.doe@example.com and bob.doe@example.com to John as well.

Good point. I assumed such false positives would be unlikely because I 
was considering very-small-scale projects, but I agree that using 
wildcards is not at all feasible for larger projects.

> Supporting hashed entries would allow for a more targeted obfuscation.
> That was discussed a while ago:
> https://lore.kernel.org/git/20210103211849.2691287-1-sandals@crustytoothpaste.net/

That was an interesting read. I agree with Ævar in that thread in that I 
think URL encoding is sufficient. I think it meets Brian's use case of 
never having to see the old name again, and my use case of obfuscating 
it from accidental discovery by friendly collaborators. While a hash 
certainly gives a stronger sense of security, I think it's a false sense 
of security, because, as you note below, recovering old email addresses 
from the tree is not much more trivial than reversing the encoding. And 
either way, a sha256 hash can easily be inverted in a few days(?) using 
a dictionary attack with email addresses from data breaches. As someone 
who has changed her name, I would be content with using a simple URL 
encoding.

>> Someone could always spend more effort to uncover the name using more
>> advanced tools, but the point of this feature is to prevent
>> accidental discovery of the name in cases where completely hiding the
>> name is not feasible.
> Extracting old email addresses from a repository is easy by comparing
> authors' email addresses without and with mailmap applied, no advanced
> tools required.  Here's mine from Git's own repo:
>
>     $ git log --format='%ae %aE' |
>       awk '$1 != $2 && !a[$0] {a[$0] = 1; print}' |
>       grep -F l.s.r@web.de
>     rene.scharfe@lsrfire.ath.cx l.s.r@web.de
>
> The same can be done with names (%an/%aN).

You're absolutely right. With "advanced tools" I was referring to 
anything more advanced than a plain `git log` ;-)

- Florine