From fa84a2ae5fa28fa4648863a74ea7d3406e58d8a9 Mon Sep 17 00:00:00 2001
From: ryan <ryan@distrust.co>
Date: Thu, 8 Aug 2024 00:35:41 -0400
Subject: [PATCH] keyfork-shard: Be less strict about keys

Rationale: Keyfork Shard runs on Airgap systems. The biggest impact of
using StandardPolicy and checking whether keys are "alive" is the drift
between different Airgap systems where the keys may not be valid at the
same time. Because of this, it is impossible to shard a secret to all
keys at once using a StandardPolicy.

However, we consider these keys to be a trusted input, whether created
by a previous system or generated directly by Keyfork. Because of this,
we can use a NullPolicy to blanketly permit all keys, the same way we
blanketly permit all keys when reconstituting the sharded secret, and
disable the check for whether keys are alive (though, we are still
denying revoked keys).
---
 crates/keyfork-shard/src/openpgp.rs | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/crates/keyfork-shard/src/openpgp.rs b/crates/keyfork-shard/src/openpgp.rs
index be4ec47..11f759a 100644
--- a/crates/keyfork-shard/src/openpgp.rs
+++ b/crates/keyfork-shard/src/openpgp.rs
@@ -25,7 +25,7 @@ use openpgp::{
         stream::{DecryptionHelper, DecryptorBuilder, VerificationHelper},
         Parse,
     },
-    policy::{NullPolicy, Policy, StandardPolicy},
+    policy::{NullPolicy, Policy},
     serialize::{
         stream::{ArbitraryWriter, Encryptor2, LiteralWriter, Message, Recipient, Signer},
         Marshal,
@@ -276,7 +276,7 @@ impl<P: PromptHandler> Format for OpenPGP<P> {
         key_data: &[Self::PublicKey],
         threshold: u8,
     ) -> Result<Self::EncryptedData, Self::Error> {
-        let policy = StandardPolicy::new();
+        let policy = NullPolicy::new();
         let mut pp = vec![SHARD_METADATA_VERSION, threshold];
         // Note: Sequoia does not export private keys on a Cert, only on a TSK
         signing_key
@@ -362,7 +362,7 @@ impl<P: PromptHandler> Format for OpenPGP<P> {
         public_key: &Cert,
         signing_key: &mut Self::SigningKey,
     ) -> Result<EncryptedMessage> {
-        let policy = StandardPolicy::new();
+        let policy = NullPolicy::new();
         let valid_cert = public_key
             .with_policy(&policy, None)
             .map_err(Error::Sequoia)?;
@@ -577,7 +577,8 @@ fn get_encryption_keys<'a>(
     openpgp::packet::key::UnspecifiedRole,
 > {
     cert.keys()
-        .alive()
+        // NOTE: this causes complications on Airgap systems
+        // .alive()
         .revoked(false)
         .supported()
         .for_storage_encryption()