improve GnuPG configuration file `/etc/skel/.gnupg/gpg.conf`

[adrelanos]

Stronger ciphers?

Any other hardening suggestions?

https://github.com/Kicksecure/security-misc/blob/master/etc/skel/.gnupg/gpg.conf

https://forums.whonix.org/t/anon-gpg-tweaks-gpg-conf-enhancements-duraconf-a-collection-of-hardened-configuration-files/5378

https://www.kicksecure.com/wiki/Air_Gapped_OpenPGP_Key

https://www.kicksecure.com/wiki/OpenPGP

[monsieuremre]

This should not be too hard. Just choose the one that keeps winning the cipher competitions.

Also, we should make post quantum options the default as soon as possible, for the asymmetric stuff I mean.

Reasonable path for the future is follow this draft really closely.

There are individual post-quantom implementations, but these are not standardized. We should just follow closely the developments in standardization of this. Many big boy projects are already sponsoring the development of such standards. These will be available in the wild. We just want to be ahead of the curve to adapt. Not to mention, the other side should also support these technologies for them to work as intended.

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[adrelanos]

Unless using live mode, writing to RAM is too difficult for users.

/tmp isn't guaranteeing that nothing is written to the disk. (Swap, crash dumps. This goes into the topic of anti-forensics. In short: forget about it and use live mode.)

But what is the point of writing to RAM anyhow in this context? The private key needs to be stored persistently somewhere anyhow.

​

​

[ben-grande]

Another hardend GnuPG configuration:

• https://gist.github.com/sebmellen/b0d0424caefa1221cbe4d9aaf2172d2c

[ben-grande]

Thats many years old and wonder if key size beyond 4096 are really more secure at this point?

1. Many years old and still newer than the currently used gpg.conf.
2. I didn't say to trust everything in that file, it has outdated settings, yes, but it has many valuable ones.

[Nishiji-eng]

@adrelanos
So I looked at the current settings and here are some suggestions 😉

---

Ciphers
Use only the strongest and most widely accepted algorithms for symmetric ciphers
personal-cipher-preferences AES256 AES192 AES128 CAMELLIA256 CAMELLIA192 CAMELLIA128 TWOFISH

Note: Two strong ciphers SERPENT and CHACHA20 are not supported by OpenPGP as of yet.

Disable/Remove legacy ciphers
NIST disallowed the use of 3DES after 2023 for many applications. It only offers 112 bits of security (due to meet-in-the-middle attacks), which is less than recommended minimums.
disable-cipher-algo 3DES

Others to maybe disable would be Legacy ciphers like IDEA and CAST5 but CAST5 is still used for compatibility.
disable-cipher-algo IDEA

---

Disable/Remove legacy digests
Only do this if you never need backwards compatibility.

week-digest MD5
week-digest SHA1

---

Secure Memory

Tells GnuPG to require secure memory (protected memory that can't be swapped to disk) for storing sensitive data like passphrases and private keys while running.
require-secmem

[adrelanos]

AI generated?

[Nishiji-eng]

I had my reply typed up and used Copilot to help me format this, but it sneaked in some extra content. Oopsies My bad! 🙈

disable-digest-algo is not what I had originally and is incorrect, week-digest is the correct one man gpg | grep -i -A 1 "weak-digest"

GPG by default does not automatically retrieve keys from key servers, therefore no-auto-key-retrieve might be redundant but if you wanted you can add to the existing one keyserver-options no-honor-keyserver-url no-auto-key-retrieve. Same goes for require-secmem (GnuPG 2.2 and Later) it doesn't say its depreciated in manpage per say but might default to using secmem and warn when it doesn't anyway 🤷

personal-digest-preferences looks like it is already set by default-preference-list but this has me wondering about the behavior of default-preference-list vs (personal-cipher-preferences personal-compress-preferences personal-digest-preferences) all three set separately?

This is the few suggestions I have compared to what is set.

# Set strong personal digests preferences to use best available digest
personal-digest-preferences SHA512 SHA384 SHA256
# Disable use of weak/legacy ciphers
disable-cipher-algo 3DES IDEA
# Reject weak/legacy digests
weak-digest MD5 SHA1
# Require secure memory
require-secmem

On a closing note GnuPG doesn’t support Serpent or ChaCha20, which are strong ciphers. 😔 Needless to say, I haven't found anything on the progress or updates on post quantum in GnuPG.. Fingers crossed they’ll add it soon! 🤞

Hope this helps 💖

[adrelanos]

Our plan during the Kicksecure 18 release cycle is to port to Sequoia-PGP.