Reset mtime of source private keys to default creation time #6270
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Codecov Report
@@ Coverage Diff @@
## develop #6270 +/- ##
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- Coverage 84.09% 84.07% -0.02%
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Files 60 60
Lines 4199 4208 +9
Branches 506 508 +2
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+ Hits 3531 3538 +7
- Misses 548 549 +1
- Partials 120 121 +1
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We set the GPG key creation time to 2013-05-14 to hide when they were created, revealing when a source started using SecureDrop. However this information was being leaked via the file modification time of the private key material in the $keydir/private-keys-v1.d/ folder. While we can easily change a file's mtime to a past date, faking the ctime really isn't possible. So instead we touch each private key when the source app starts to mask the real creation time. Because of the nightly restarts, this will be updated within 24 hours of source creation. Fixes freedomofpress/securedrop-security#71.
zenmonkeykstop
approved these changes
Feb 16, 2022
This was referenced Feb 16, 2022
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Status
Ready for review
Description of Changes
We set the GPG key creation time to 2013-05-14 to hide when they
were created, revealing when a source started using SecureDrop. However
this information was being leaked via the file modification time of the
private key material in the $keydir/private-keys-v1.d/ folder.
We set the GPG key creation time to 2013-05-14 to hide when they
were created, revealing when a source started using SecureDrop. However
this information was being leaked via the file modification time of the
private key material in the $keydir/private-keys-v1.d/ folder.
While we can easily change a file's mtime to a past date, faking the
ctime really isn't possible. So instead we touch each private key when
the source app starts to mask the real creation time. Because of the
nightly restarts, this will be updated within 24 hours of source
creation.
Fixes https://github.com/freedomofpress/securedrop-security/issues/71.
Testing
/var/lib/securedrop/keys/private-keys-v1.d, wait a minute, make a whitespace-only change tosource_app/__init__.pyso the auto reloader restarts the app. Look at mtime+ctime of private keys, they should be different.Deployment
Any special considerations for deployment? Not really.
Checklist
make lint) and tests (make test) pass in the development container