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hey, author here, happy to answer questions, and would love to hear from anyone using the library :)

by dignifiedquire 2y ago

LtWorf 2y ago
Does it support smart cards and such devices?
- dignifiedquire 2y ago
  it‘s not builtin, but possible to integrate with @wiktor-k is working on a tool to use rpgp to provide a simple solution to work with smartcards
  - wiktor-k 2y ago
    Yep. We've got it working with OpenPGP Card devices (Yubikeys, Nitorkeys, etc.). The signing part was actually pretty easy and the decryption required a bit more work but the maintainer was super responsive (https://github.com/rpgp/rpgp/pull/315 https://github.com/rpgp/rpgp/pull/315). Overall I'm pretty happy with the codebase. The PoC for using cards in git is in https://github.com/wiktor-k/monkeybagel https://github.com/wiktor-k/monkeybagel (excuse the silly name ;).
    - rendaw 2y ago
      How does it interface with the cards? IIRC the rust pcsc library used by Sequoia needed C libraries. I've been doing some NFC stuff too and was looking for a pure-rust solution if there was one.
      - wiktor-k 2y ago
        It uses this crate: https://crates.io/crates/pcsc https://crates.io/crates/pcsc On Windows and Mac it binds to system libraries. On Linux it works with pcsclite. Btw I'm not aware of any tooling that's used by Sequoia, rather wrappers that use Sequoia and pcsc crate.
Mortak 2y ago
It seems OpenPGP is still riddled with SHA-1. Git kind of avoided the problem (https://github.blog/2017-03-20-sha-1-collision-detection-on-github-com/ https://github.blog/2017-03-20-sha-1-collision-detection-on-...). What's your plan to deal with the issue?
- dignifiedquire 2y ago
  I just finished implementing sha1collision detection, and it will be integrated into rpgp soon https://github.com/rpgp/rpgp/issues/293 https://github.com/rpgp/rpgp/issues/293 This is the same algorithm used by git. There are higher level implementations that use the dates on signatures to straight out reject sha1 material, but that gives only a limited protection.
- upofadown 2y ago
  I am not aware of any outstanding SHA-1 issues that would require a change in the current RFC4880 OpenPGP standard. There was an obscure attack that involved generating two keypairs with colliding SHA-1 signatures and getting a third party to sign one of them but you can just use a different hash (say SHA256). The SHA-1 used in the MDC portion of the authenticated encryption mode doesn't and is very unlikely to ever represent any security weakness (the hash used there doesn't require any particular cryptographic properties). SHA-1 is used for the key fingerprint, but the use of a hash with collision resistance is not required in general for key fingerprints. An attacker could in theory create two different keys with the same fingerprint, but then they would just own two keys that would be hard for to distinguish from one another. You don't sign the fingerprints, you sign the actual public key. In general, it would be a bad idea to specify that the hash used for a key fingerprint required collision resistance as that would mean that the fingerprint would have to be something like an unusable 256 bits long to prevent birthday attacks.

hey, author here, happy to answer questions, and would love to hear from anyone using the library :)

LtWorf 2y ago

Does it support smart cards and such devices?

dignifiedquire 2y ago
it‘s not builtin, but possible to integrate with @wiktor-k is working on a tool to use rpgp to provide a simple solution to work with smartcards
- wiktor-k 2y ago
  Yep. We've got it working with OpenPGP Card devices (Yubikeys, Nitorkeys, etc.). The signing part was actually pretty easy and the decryption required a bit more work but the maintainer was super responsive (https://github.com/rpgp/rpgp/pull/315 https://github.com/rpgp/rpgp/pull/315). Overall I'm pretty happy with the codebase. The PoC for using cards in git is in https://github.com/wiktor-k/monkeybagel https://github.com/wiktor-k/monkeybagel (excuse the silly name ;).
  - rendaw 2y ago
    How does it interface with the cards? IIRC the rust pcsc library used by Sequoia needed C libraries. I've been doing some NFC stuff too and was looking for a pure-rust solution if there was one.
    - wiktor-k 2y ago
      It uses this crate: https://crates.io/crates/pcsc https://crates.io/crates/pcsc On Windows and Mac it binds to system libraries. On Linux it works with pcsclite. Btw I'm not aware of any tooling that's used by Sequoia, rather wrappers that use Sequoia and pcsc crate.

Mortak 2y ago

It seems OpenPGP is still riddled with SHA-1. Git kind of avoided the problem (https://github.blog/2017-03-20-sha-1-collision-detection-on-github-com/ https://github.blog/2017-03-20-sha-1-collision-detection-on-...). What's your plan to deal with the issue?

dignifiedquire 2y ago
I just finished implementing sha1collision detection, and it will be integrated into rpgp soon https://github.com/rpgp/rpgp/issues/293 https://github.com/rpgp/rpgp/issues/293 This is the same algorithm used by git. There are higher level implementations that use the dates on signatures to straight out reject sha1 material, but that gives only a limited protection.
upofadown 2y ago
I am not aware of any outstanding SHA-1 issues that would require a change in the current RFC4880 OpenPGP standard. There was an obscure attack that involved generating two keypairs with colliding SHA-1 signatures and getting a third party to sign one of them but you can just use a different hash (say SHA256). The SHA-1 used in the MDC portion of the authenticated encryption mode doesn't and is very unlikely to ever represent any security weakness (the hash used there doesn't require any particular cryptographic properties). SHA-1 is used for the key fingerprint, but the use of a hash with collision resistance is not required in general for key fingerprints. An attacker could in theory create two different keys with the same fingerprint, but then they would just own two keys that would be hard for to distinguish from one another. You don't sign the fingerprints, you sign the actual public key. In general, it would be a bad idea to specify that the hash used for a key fingerprint required collision resistance as that would mean that the fingerprint would have to be something like an unusable 256 bits long to prevent birthday attacks.