keyfork-shard: begin work on (re)provisioning shardholder keys

Cargo.lock

@@ -1700,6 +1700,10 @@ dependencies = [
  "anyhow",
 ]
 
+[[package]]
+name = "keyfork-bug"
+version = "0.1.0"
+
 [[package]]
 name = "keyfork-crossterm"
 version = "0.27.1"
@@ -1761,6 +1765,7 @@ dependencies = [
  "hex-literal",
  "hmac",
  "k256",
+ "keyfork-bug",
  "keyfork-mnemonic-util",
  "keyfork-slip10-test-data",
  "ripemd",
@@ -1773,6 +1778,7 @@ dependencies = [
 name = "keyfork-entropy"
 version = "0.1.0"
 dependencies = [
+ "keyfork-bug",
  "smex",
 ]
 
@@ -1788,11 +1794,12 @@ dependencies = [
 
 [[package]]
 name = "keyfork-mnemonic-util"
-version = "0.1.0"
+version = "0.2.0"
 dependencies = [
  "bip39",
  "hex",
  "hmac",
+ "keyfork-bug",
  "pbkdf2",
  "serde_json",
  "sha2",
@@ -1803,6 +1810,7 @@ dependencies = [
 name = "keyfork-prompt"
 version = "0.1.0"
 dependencies = [
+ "keyfork-bug",
  "keyfork-crossterm",
  "keyfork-mnemonic-util",
  "thiserror",
@@ -1813,6 +1821,7 @@ name = "keyfork-qrcode"
 version = "0.1.0"
 dependencies = [
  "image",
+ "keyfork-bug",
  "keyfork-zbar",
  "rqrr",
  "thiserror",
@@ -1828,7 +1837,9 @@ dependencies = [
  "card-backend",
  "card-backend-pcsc",
  "hkdf",
+ "keyfork-bug",
  "keyfork-derive-openpgp",
+ "keyfork-derive-util",
  "keyfork-mnemonic-util",
  "keyfork-prompt",
  "keyfork-qrcode",
@@ -1873,6 +1884,7 @@ version = "0.1.0"
 dependencies = [
  "bincode",
  "hex-literal",
+ "keyfork-bug",
  "keyfork-derive-path-data",
  "keyfork-derive-util",
  "keyfork-frame",

Cargo.toml

@@ -15,6 +15,7 @@ members = [
     "crates/qrcode/keyfork-zbar",
     "crates/qrcode/keyfork-zbar-sys",
     "crates/util/keyfork-bin",
+    "crates/util/keyfork-bug",
     "crates/util/keyfork-crossterm",
     "crates/util/keyfork-entropy",
     "crates/util/keyfork-frame",

Makefile

@@ -1,3 +1,6 @@
+.PHONY: default
+default: docs/book
+
 BASE_REF ?= main
 HEAD_REF ?= HEAD
 
@@ -13,6 +16,7 @@ endef
 docs/book: docs/src/links.md $(shell find docs/src -type f -name '*.md')
 	mdbook build docs
 	mkdir -p docs/book/rustdoc
+	cargo test --doc
 	cargo doc --no-deps
 	cp -r ${CARGO_TARGET_DIR}/doc/* docs/book/rustdoc/
 

crates/daemon/keyforkd-client/Cargo.toml

@@ -12,14 +12,14 @@ ed25519 = ["keyfork-derive-util/ed25519", "ed25519-dalek"]
 secp256k1 = ["keyfork-derive-util/secp256k1", "k256"]
 
 [dependencies]
-keyfork-derive-util = { version = "0.1.0", path = "../../derive/keyfork-derive-util", default-features = false }
+keyfork-derive-util = { version = "0.1.0", path = "../../derive/keyfork-derive-util", default-features = false, registry = "distrust" }
-keyfork-frame = { version = "0.1.0", path = "../../util/keyfork-frame" }
+keyfork-frame = { version = "0.1.0", path = "../../util/keyfork-frame", registry = "distrust" }
-keyforkd-models = { version = "0.1.0", path = "../keyforkd-models" }
+keyforkd-models = { version = "0.1.0", path = "../keyforkd-models", registry = "distrust" }
 bincode = "1.3.3"
 thiserror = "1.0.49"
 k256 = { version = "0.13.3", optional = true }
 ed25519-dalek = { version = "2.1.1", optional = true }
 
 [dev-dependencies]
-keyfork-slip10-test-data = { path = "../../util/keyfork-slip10-test-data" }
+keyfork-slip10-test-data = { path = "../../util/keyfork-slip10-test-data", registry = "distrust" }
-keyforkd = { path = "../keyforkd" }
+keyforkd = { path = "../keyforkd", registry = "distrust" }

crates/daemon/keyforkd-models/Cargo.toml

@@ -7,6 +7,6 @@ license = "MIT"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-keyfork-derive-util = { version = "0.1.0", path = "../../derive/keyfork-derive-util", default-features = false }
+keyfork-derive-util = { version = "0.1.0", path = "../../derive/keyfork-derive-util", default-features = false, registry = "distrust" }
 serde = { version = "1.0.190", features = ["derive"] }
 thiserror = "1.0.50"

crates/daemon/keyforkd/Cargo.toml

@@ -12,11 +12,12 @@ tracing = ["tower/tracing", "tokio/tracing", "dep:tracing", "dep:tracing-subscri
 multithread = ["tokio/rt-multi-thread"]
 
 [dependencies]
-keyfork-derive-util = { version = "0.1.0", path = "../../derive/keyfork-derive-util" }
+keyfork-bug = { version = "0.1.0", path = "../../util/keyfork-bug", registry = "distrust" }
-keyfork-frame = { version = "0.1.0", path = "../../util/keyfork-frame" }
+keyfork-derive-util = { version = "0.1.0", path = "../../derive/keyfork-derive-util", registry = "distrust" }
-keyfork-mnemonic-util = { version = "0.1.0", path = "../../util/keyfork-mnemonic-util" }
+keyfork-frame = { version = "0.1.0", path = "../../util/keyfork-frame", features = ["async"], registry = "distrust" }
-keyfork-derive-path-data = { version = "0.1.0", path = "../../derive/keyfork-derive-path-data" }
+keyfork-mnemonic-util = { version = "0.2.0", path = "../../util/keyfork-mnemonic-util", registry = "distrust" }
-keyforkd-models = { version = "0.1.0", path = "../keyforkd-models" }
+keyfork-derive-path-data = { version = "0.1.0", path = "../../derive/keyfork-derive-path-data", registry = "distrust" }
+keyforkd-models = { version = "0.1.0", path = "../keyforkd-models", registry = "distrust" }
 
 # Not personally audited
 bincode = "1.3.3"
@@ -35,4 +36,4 @@ tempfile = { version = "3.10.0", default-features = false }
 
 [dev-dependencies]
 hex-literal = "0.4.1"
-keyfork-slip10-test-data = { path = "../../util/keyfork-slip10-test-data" }
+keyfork-slip10-test-data = { path = "../../util/keyfork-slip10-test-data", registry = "distrust" }

crates/daemon/keyforkd/src/test_util.rs

@@ -7,6 +7,8 @@ use crate::{middleware, Keyforkd, ServiceBuilder, UnixServer};
 
 use tokio::runtime::Builder;
 
+use keyfork_bug::bug;
+
 #[derive(Debug, thiserror::Error)]
 #[error("This error can never be instantiated")]
 #[doc(hidden)]
@@ -54,8 +56,10 @@ where
         .worker_threads(2)
         .enable_io()
         .build()
-        .expect("tokio threaded IO runtime");
+        .expect(bug!(
-    let socket_dir = tempfile::tempdir().expect("can't create tempdir");
+            "can't make tokio threaded IO runtime, should be enabled via feature flags"
+        ));
+    let socket_dir = tempfile::tempdir().expect(bug!("can't create tempdir"));
     let socket_path = socket_dir.path().join("keyforkd.sock");
     rt.block_on(async move {
         let (tx, mut rx) = tokio::sync::mpsc::channel(1);
@@ -63,25 +67,28 @@ where
             let socket_path = socket_path.clone();
             let seed = seed.to_vec();
             async move {
-                let mut server = UnixServer::bind(&socket_path).expect("can't bind unix socket");
+                let mut server =
-                tx.send(()).await.expect("couldn't send server start signal");
+                    UnixServer::bind(&socket_path).expect(bug!("can't bind unix socket"));
+                tx.send(())
+                    .await
+                    .expect(bug!("couldn't send server start signal"));
                 let service = ServiceBuilder::new()
                     .layer(middleware::BincodeLayer::new())
                     .service(Keyforkd::new(seed.to_vec()));
-                server.run(service).await.unwrap();
+                server.run(service).await.expect(bug!("Unable to start service"));
             }
         });
 
         rx.recv()
             .await
-            .expect("can't receive server start signal from channel");
+            .expect(bug!("can't receive server start signal from channel"));
         let test_handle = tokio::task::spawn_blocking(move || closure(&socket_path));
 
         let result = test_handle.await;
         server_handle.abort();
         result
     })
-    .expect("runtime could not join all threads")
+    .expect(bug!("runtime could not join all threads"))
 }
 
 #[cfg(test)]

crates/derive/keyfork-derive-key/Cargo.toml

@@ -7,7 +7,7 @@ license = "AGPL-3.0-only"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-keyfork-derive-util = { version = "0.1.0", path = "../keyfork-derive-util" }
+keyfork-derive-util = { version = "0.1.0", path = "../keyfork-derive-util", registry = "distrust" }
-keyforkd-client = { version = "0.1.0", path = "../../daemon/keyforkd-client" }
+keyforkd-client = { version = "0.1.0", path = "../../daemon/keyforkd-client", registry = "distrust" }
-smex = { version = "0.1.0", path = "../../util/smex" }
+smex = { version = "0.1.0", path = "../../util/smex", registry = "distrust" }
 thiserror = "1.0.48"

crates/derive/keyfork-derive-openpgp/Cargo.toml

@@ -6,12 +6,12 @@ license = "AGPL-3.0-only"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 [features]
-default = []
+default = ["bin"]
 bin = ["sequoia-openpgp/crypto-nettle"]
 
 [dependencies]
-keyfork-derive-util = { version = "0.1.0", path = "../keyfork-derive-util", default-features = false, features = ["ed25519"] }
+keyfork-derive-util = { version = "0.1.0", path = "../keyfork-derive-util", default-features = false, features = ["ed25519"], registry = "distrust" }
-keyforkd-client = { version = "0.1.0", path = "../../daemon/keyforkd-client", default-features = false, features = ["ed25519"] }
+keyforkd-client = { version = "0.1.0", path = "../../daemon/keyforkd-client", default-features = false, features = ["ed25519"], registry = "distrust" }
 ed25519-dalek = "2.0.0"
 sequoia-openpgp = { version = "1.17.0", default-features = false }
 anyhow = "1.0.75"

crates/derive/keyfork-derive-openpgp/src/main.rs

@@ -78,9 +78,7 @@ fn validate(
     subkey_format: &str,
     default_userid: &str,
 ) -> Result<(DerivationPath, Vec<KeyType>, UserID), Box<dyn std::error::Error>> {
-    let mut pgp_u32 = [0u8; 4];
+    let index = DerivationIndex::new(u32::from_be_bytes(*b"\x00pgp"), true)?;
-    pgp_u32[1..].copy_from_slice(&"pgp".bytes().collect::<Vec<u8>>());
-    let index = DerivationIndex::new(u32::from_be_bytes(pgp_u32), true)?;
 
     let path = DerivationPath::from_str(path)?;
     assert_eq!(2, path.len(), "Expected path of m/{index}/account_id'");

crates/derive/keyfork-derive-path-data/Cargo.toml

@@ -7,4 +7,4 @@ license = "MIT"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-keyfork-derive-util = { version = "0.1.0", path = "../keyfork-derive-util", default-features = false }
+keyfork-derive-util = { version = "0.1.0", path = "../keyfork-derive-util", default-features = false, registry = "distrust" }

crates/derive/keyfork-derive-util/Cargo.toml

@@ -12,7 +12,8 @@ secp256k1 = ["k256"]
 ed25519 = ["ed25519-dalek"]
 
 [dependencies]
-keyfork-mnemonic-util = { version = "0.1.0", path = "../../util/keyfork-mnemonic-util" }
+keyfork-mnemonic-util = { version = "0.2.0", path = "../../util/keyfork-mnemonic-util", registry = "distrust" }
+keyfork-bug = { version = "0.1.0", path = "../../util/keyfork-bug", registry = "distrust" }
 
 # Included in Rust
 digest = "0.10.7"
@@ -32,4 +33,4 @@ ed25519-dalek = { version = "2.0.0", optional = true }
 
 [dev-dependencies]
 hex-literal = "0.4.1"
-keyfork-slip10-test-data = { version = "0.1.0", path = "../../util/keyfork-slip10-test-data" }
+keyfork-slip10-test-data = { version = "0.1.0", path = "../../util/keyfork-slip10-test-data", registry = "distrust" }

crates/derive/keyfork-derive-util/src/extended_key/private_key.rs

@@ -1,5 +1,7 @@
 use crate::{DerivationIndex, DerivationPath, ExtendedPublicKey, PrivateKey, PublicKey};
 
+use keyfork_bug::bug;
+
 use hmac::{Hmac, Mac};
 use serde::{Deserialize, Serialize};
 use sha2::Sha512;
@@ -124,7 +126,7 @@ mod serde_with {
         let variable_len_bytes = <&[u8]>::deserialize(deserializer)?;
         let bytes: [u8; 32] = variable_len_bytes
             .try_into()
-            .expect("unable to parse serialized private key; no support for static len");
+            .expect(bug!("unable to parse serialized private key; no support for static len"));
         Ok(K::from_bytes(&bytes))
     }
 }
@@ -171,7 +173,7 @@ where
 
     fn new_internal(seed: &[u8]) -> Self {
         let hash = HmacSha512::new_from_slice(&K::key().bytes().collect::<Vec<_>>())
-            .expect("HmacSha512 InvalidLength should be infallible")
+            .expect(bug!("HmacSha512 InvalidLength should be infallible"))
             .chain_update(seed)
             .finalize()
             .into_bytes();
@@ -180,10 +182,10 @@ where
         Self::new_from_parts(
             private_key
                 .try_into()
-                .expect("KEY_SIZE / 8 did not give a 32 byte slice"),
+                .expect(bug!("KEY_SIZE / 8 did not give a 32 byte slice")),
             0,
             // Checked: chain_code is always the same length, hash is static size
-            chain_code.try_into().expect("Invalid chain code length"),
+            chain_code.try_into().expect(bug!("Invalid chain code length")),
         )
     }
 
@@ -405,7 +407,7 @@ where
         let depth = self.depth.checked_add(1).ok_or(Error::Depth)?;
 
         let mut hmac = HmacSha512::new_from_slice(&self.chain_code)
-            .expect("HmacSha512 InvalidLength should be infallible");
+            .expect(bug!("HmacSha512 InvalidLength should be infallible"));
         if index.is_hardened() {
             hmac.update(&[0]);
             hmac.update(&self.private_key.to_bytes());
@@ -423,7 +425,7 @@ where
             .derive_child(
                 &private_key
                     .try_into()
-                    .expect("Invalid length for private key"),
+                    .expect(bug!("Invalid length for private key")),
             )
             .map_err(|_| Error::Derivation)?;
 
@@ -432,7 +434,7 @@ where
             depth,
             chain_code: chain_code
                 .try_into()
-                .expect("Invalid length for chain code"),
+                .expect(bug!("Invalid length for chain code")),
         })
     }
 }

crates/derive/keyfork-derive-util/src/extended_key/public_key.rs

@@ -4,6 +4,8 @@ use hmac::{Hmac, Mac};
 use sha2::Sha512;
 use thiserror::Error;
 
+use keyfork_bug::bug;
+
 const KEY_SIZE: usize = 256;
 
 /// Errors associated with creating or deriving Extended Public Keys.
@@ -142,9 +144,11 @@ where
         let (child_key, chain_code) = hmac.split_at(KEY_SIZE / 8);
         let derived_key = self
             .public_key
-            .derive_child(child_key.try_into().expect("Invalid key length"))
+            .derive_child(child_key.try_into().expect(bug!("Invalid key length")))
             .map_err(|_| Error::Derivation)?;
-        let chain_code = chain_code.try_into().expect("Invalid chain code length");
+        let chain_code = chain_code
+            .try_into()
+            .expect(bug!("Invalid chain code length"));
 
         Ok(Self {
             public_key: derived_key,

crates/derive/keyfork-derive-util/src/private_key.rs

@@ -2,6 +2,8 @@ use crate::PublicKey;
 
 use thiserror::Error;
 
+use keyfork_bug::bug;
+
 pub(crate) type PrivateKeyBytes = [u8; 32];
 
 /// Functions required to use an `ExtendedPrivateKey`.
@@ -115,7 +117,7 @@ impl PrivateKey for k256::SecretKey {
     }
 
     fn from_bytes(b: &PrivateKeyBytes) -> Self {
-        Self::from_slice(b).expect("Invalid private key bytes")
+        Self::from_slice(b).expect(bug!("Invalid private key bytes"))
     }
 
     fn to_bytes(&self) -> PrivateKeyBytes {
@@ -134,13 +136,13 @@ impl PrivateKey for k256::SecretKey {
         let other = *other;
         // Checked: See above nonzero check
         let scalar = Option::<NonZeroScalar>::from(NonZeroScalar::from_repr(other.into()))
-            .expect("Should have been able to get a NonZeroScalar");
+            .expect(bug!("Should have been able to get a NonZeroScalar"));
 
         let derived_scalar = self.to_nonzero_scalar().as_ref() + scalar.as_ref();
         Ok(
             Option::<NonZeroScalar>::from(NonZeroScalar::new(derived_scalar))
                 .map(Into::into)
-                .expect("Should be able to make Key"),
+                .expect(bug!("Should be able to make Key")),
         )
     }
 }

crates/derive/keyfork-derive-util/src/public_key.rs

@@ -5,6 +5,8 @@ use ripemd::Ripemd160;
 use sha2::Sha256;
 use thiserror::Error;
 
+use keyfork_bug::bug;
+
 pub(crate) type PublicKeyBytes = [u8; 33];
 
 /// Functions required to use an `ExtendedPublicKey`.
@@ -63,7 +65,7 @@ pub trait PublicKey: Sized {
         // Note: Safety assured by type returned from Ripemd160
         hash[..4]
             .try_into()
-            .expect("Ripemd160 returned too little data")
+            .expect(bug!("Ripemd160 returned too little data"))
     }
 }
 
@@ -108,10 +110,11 @@ impl PublicKey for k256::PublicKey {
         }
         // Checked: See above
         let scalar = Option::<NonZeroScalar>::from(NonZeroScalar::from_repr(other.into()))
-            .expect("Should have been able to get a NonZeroScalar");
+            .expect(bug!("Should have been able to get a NonZeroScalar"));
 
         let point = self.to_projective() + (AffinePoint::generator() * *scalar);
-        Ok(Self::from_affine(point.into()).expect("Could not from_affine after scalar arithmetic"))
+        Ok(Self::from_affine(point.into())
+            .expect(bug!("Could not from_affine after scalar arithmetic")))
     }
 }
 
@@ -150,10 +153,11 @@ impl TestPublicKey {
     #[allow(dead_code)]
     pub fn from_bytes(b: &[u8]) -> Self {
         Self {
-            key: b.try_into().unwrap(),
+            key: b
+                .try_into()
+                .expect(bug!("invalid size when constructing TestPublicKey")),
         }
     }
-
 }
 
 impl PublicKey for TestPublicKey {

crates/derive/keyfork-derive-util/src/request.rs

@@ -197,7 +197,6 @@ impl DerivationRequest {
     /// let mnemonic: keyfork_mnemonic_util::Mnemonic = //
     /// #   keyfork_mnemonic_util::Mnemonic::from_entropy(
     /// #   b"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA",
-    /// #   Default::default(),
     /// #   )?;
     /// let algo: DerivationAlgorithm = //
     /// #   DerivationAlgorithm::Internal;

crates/keyfork-shard/Cargo.toml

@@ -14,25 +14,27 @@ openpgp-card = ["openpgp-card-sequoia", "card-backend-pcsc", "card-backend", "de
 qrcode = ["keyfork-qrcode"]
 
 [dependencies]
-keyfork-prompt = { version = "0.1.0", path = "../util/keyfork-prompt", default-features = false, features = ["mnemonic"] }
+keyfork-bug = { version = "0.1.0", path = "../util/keyfork-bug", registry = "distrust" }
-keyfork-qrcode = { version = "0.1.0", path = "../qrcode/keyfork-qrcode", optional = true, default-features = false }
+keyfork-prompt = { version = "0.1.0", path = "../util/keyfork-prompt", default-features = false, features = ["mnemonic"], registry = "distrust" }
-smex = { version = "0.1.0", path = "../util/smex" }
+keyfork-qrcode = { version = "0.1.0", path = "../qrcode/keyfork-qrcode", optional = true, default-features = false, registry = "distrust" }
+smex = { version = "0.1.0", path = "../util/smex", registry = "distrust" }
 
 sharks = "0.5.0"
 thiserror = "1.0.50"
 
 # Remote operator mode
-keyfork-mnemonic-util = { version = "0.1.0", path = "../util/keyfork-mnemonic-util" }
+keyfork-mnemonic-util = { version = "0.2.0", path = "../util/keyfork-mnemonic-util", registry = "distrust" }
 x25519-dalek = { version = "2.0.0", features = ["getrandom"] }
 aes-gcm = { version = "0.10.3", features = ["std"] }
 hkdf = { version = "0.12.4", features = ["std"] }
 sha2 = "0.10.8"
 
 # OpenPGP
-keyfork-derive-openpgp = { version = "0.1.0", path = "../derive/keyfork-derive-openpgp" }
+keyfork-derive-openpgp = { version = "0.1.0", path = "../derive/keyfork-derive-openpgp", default-features = false, registry = "distrust" }
 anyhow = { version = "1.0.79", optional = true }
 card-backend = { version = "0.2.0", optional = true }
 card-backend-pcsc = { version = "0.5.0", optional = true }
 openpgp-card-sequoia = { version = "0.2.0", optional = true, default-features = false }
 openpgp-card = { version = "0.4.0", optional = true }
 sequoia-openpgp = { version = "1.17.0", optional = true, default-features = false }
+keyfork-derive-util = { version = "0.1.0", path = "../derive/keyfork-derive-util", default-features = false }

crates/keyfork-shard/src/bin/keyfork-shard-combine-openpgp.rs

@@ -7,6 +7,7 @@ use std::{
     process::ExitCode,
 };
 
+use keyfork_prompt::{DefaultTerminal, default_terminal};
 use keyfork_shard::{openpgp::OpenPGP, Format};
 
 type Result<T, E = Box<dyn std::error::Error>> = std::result::Result<T, E>;
@@ -31,8 +32,10 @@ fn run() -> Result<()> {
         _ => panic!("Usage: {program_name} <shard> [key_discovery]"),
     };
 
-    let openpgp = OpenPGP;
+    let openpgp = OpenPGP::<DefaultTerminal>::new();
-    let bytes = openpgp.decrypt_all_shards_to_secret(key_discovery.as_deref(), messages_file)?;
+    let prompt_handler = default_terminal()?;
+
+    let bytes = openpgp.decrypt_all_shards_to_secret(key_discovery.as_deref(), messages_file, prompt_handler)?;
     print!("{}", smex::encode(bytes));
 
     Ok(())

crates/keyfork-shard/src/bin/keyfork-shard-decrypt-openpgp.rs

@@ -7,6 +7,7 @@ use std::{
     process::ExitCode,
 };
 
+use keyfork_prompt::{DefaultTerminal, default_terminal};
 use keyfork_shard::{Format, openpgp::OpenPGP};
 
 type Result<T, E = Box<dyn std::error::Error>> = std::result::Result<T, E>;
@@ -31,9 +32,10 @@ fn run() -> Result<()> {
         _ => panic!("Usage: {program_name} <shard> [key_discovery]"),
     };
 
-    let openpgp = OpenPGP;
+    let openpgp = OpenPGP::<DefaultTerminal>::new();
+    let prompt_handler = default_terminal()?;
 
-    openpgp.decrypt_one_shard_for_transport(key_discovery.as_deref(), messages_file)?;
+    openpgp.decrypt_one_shard_for_transport(key_discovery.as_deref(), messages_file, prompt_handler)?;
 
     Ok(())
 }

crates/keyfork-shard/src/bin/keyfork-shard-split-openpgp.rs

@@ -2,6 +2,7 @@
 
 use std::{env, path::PathBuf, process::ExitCode, str::FromStr};
 
+use keyfork_prompt::terminal::DefaultTerminal;
 use keyfork_shard::{Format, openpgp::OpenPGP};
 
 #[derive(Clone, Debug)]
@@ -50,7 +51,7 @@ fn run() -> Result<()> {
         smex::decode(line?)?
     };
 
-    let openpgp = OpenPGP;
+    let openpgp = OpenPGP::<DefaultTerminal>::new();
 
     openpgp.shard_and_encrypt(threshold, max, &input, key_discovery.as_path(), std::io::stdout())?;
     Ok(())

crates/keyfork-shard/src/lib.rs

@@ -1,12 +1,18 @@
 #![doc = include_str!("../README.md")]
+#![allow(clippy::expect_fun_call)]
 
-use std::io::{stdin, stdout, Read, Write};
+use std::{
+    io::{stdin, stdout, Read, Write},
+    sync::{Arc, Mutex},
+};
 
 use aes_gcm::{
     aead::{consts::U12, Aead, AeadCore, OsRng},
     Aes256Gcm, KeyInit, Nonce,
 };
 use hkdf::Hkdf;
+use keyfork_bug::{bug, POISONED_MUTEX};
+use keyfork_derive_util::{DerivationIndex, DerivationPath};
 use keyfork_mnemonic_util::{English, Mnemonic};
 use keyfork_prompt::{
     validators::{mnemonic::MnemonicSetValidator, Validator},
@@ -60,6 +66,52 @@ pub trait Format {
     /// A type representing the parsed, but encrypted, Shard data.
     type EncryptedData;
 
+    /// Provision hardware with a deterministic key based on a shardholder's DerivationIndex.
+    ///
+    /// The derivation path for provisioned shardholder keys is built using the following template:
+    /// `m / purpose ' / shard_index ' / shardholder_index '`.
+    ///
+    /// Purpose is defined by the Format, and can be a four-byte sequence transformed into a u32
+    /// using `u32::from_be_bytes(*purpose)`. For OpenPGP, for legacy reasons, this purpose is
+    /// "\x00pgp". The purpose can be _any_ sequence of four bytes so long as the _first_ byte is
+    /// not higher than 0x80 (meaning, all ASCII / 7-bit characters are allowed).
+    ///
+    /// The shard index is provided by Keyfork, and is equivalent to b"shrd".
+    ///
+    /// The shardholder index is how Keyfork is able to recreate keys for specific shardholders -
+    /// the only necessary information is which shardholder is not accounted for. Shardholders are
+    /// encouraged to mark hardware with the shardholder number so shardholders can verify their
+    /// index.
+    fn provision_shardholder_key(
+        &self,
+        derivation_path: DerivationPath,
+        seed: &[u8],
+    ) -> Result<(), Self::Error>;
+
+    /// Return a DerivationIndex for the Format.
+    ///
+    /// The derivation path for provisioned shardholder keys is built using the following template:
+    /// `m / purpose ' / shard_index ' / shardholder_index '`.
+    ///
+    /// Purpose is defined by the Format, and can be a four-byte sequence transformed into a u32
+    /// using `u32::from_be_bytes(*purpose)`. For OpenPGP, for legacy reasons, this purpose is
+    /// "\x00pgp". The purpose can be _any_ sequence of four bytes so long as the _first_ byte is
+    /// not higher than 0x80 (meaning, all ASCII / 7-bit characters are allowed).
+    fn purpose_derivation_index(&self) -> DerivationIndex;
+
+    /// Create a shardholder derivation path for the given format.
+    ///
+    /// The derivation path for provisioned shardholder keys is built using the following template:
+    /// `m / purpose ' / shard_index ' / shardholder_index '`.
+    fn create_derivation_path(&self, shardholder_index: DerivationIndex) -> DerivationPath {
+        let purpose = self.purpose_derivation_index();
+        let shard_index = DerivationIndex::new(u32::from_be_bytes(*b"shrd"), true).unwrap();
+        DerivationPath::default()
+            .chain_push(purpose)
+            .chain_push(shard_index)
+            .chain_push(shardholder_index)
+    }
+
     /// Derive a signer
     fn derive_signing_key(&self, seed: &[u8]) -> Self::SigningKey;
 
@@ -122,6 +174,7 @@ pub trait Format {
         &self,
         private_keys: Option<Self::PrivateKeyData>,
         encrypted_messages: &[Self::EncryptedData],
+        prompt: Arc<Mutex<impl PromptHandler>>,
     ) -> Result<(Vec<Share>, u8), Self::Error>;
 
     /// Decrypt a single share and associated metadata from a reaable input. For the current
@@ -135,6 +188,7 @@ pub trait Format {
         &self,
         private_keys: Option<Self::PrivateKeyData>,
         encrypted_data: &[Self::EncryptedData],
+        prompt: Arc<Mutex<impl PromptHandler>>,
     ) -> Result<(Share, u8), Self::Error>;
 
     /// Decrypt multiple shares and combine them to recreate a secret.
@@ -146,12 +200,17 @@ pub trait Format {
         &self,
         private_key_discovery: Option<impl KeyDiscovery<Self>>,
         reader: impl Read + Send + Sync,
+        prompt: impl PromptHandler,
     ) -> Result<Vec<u8>, Box<dyn std::error::Error>> {
         let private_keys = private_key_discovery
             .map(|p| p.discover_private_keys())
             .transpose()?;
         let encrypted_messages = self.parse_shard_file(reader)?;
-        let (shares, threshold) = self.decrypt_all_shards(private_keys, &encrypted_messages)?;
+        let (shares, threshold) = self.decrypt_all_shards(
+            private_keys,
+            &encrypted_messages,
+            Arc::new(Mutex::new(prompt)),
+        )?;
 
         let secret = Sharks(threshold)
             .recover(&shares)
@@ -171,8 +230,9 @@ pub trait Format {
         &self,
         private_key_discovery: Option<impl KeyDiscovery<Self>>,
         reader: impl Read + Send + Sync,
+        prompt: impl PromptHandler,
     ) -> Result<(), Box<dyn std::error::Error>> {
-        let mut pm = Terminal::new(stdin(), stdout())?;
+        let prompt = Arc::new(Mutex::new(prompt));
 
         // parse input
         let private_keys = private_key_discovery
@@ -187,7 +247,10 @@ pub trait Format {
         // receive remote data via scanning QR code from camera
         #[cfg(feature = "qrcode")]
         {
-            pm.prompt_message(PromptMessage::Text(QRCODE_PROMPT.to_string()))?;
+            prompt
+                .lock()
+                .expect(bug!(POISONED_MUTEX))
+                .prompt_message(PromptMessage::Text(QRCODE_PROMPT.to_string()))?;
             if let Ok(Some(hex)) =
                 keyfork_qrcode::scan_camera(std::time::Duration::from_secs(30), 0)
             {
@@ -195,7 +258,10 @@ pub trait Format {
                 nonce_data = Some(decoded_data[..12].try_into().map_err(|_| InvalidData)?);
                 pubkey_data = Some(decoded_data[12..].try_into().map_err(|_| InvalidData)?)
             } else {
-                pm.prompt_message(PromptMessage::Text(QRCODE_ERROR.to_string()))?;
+                prompt
+                    .lock()
+                    .expect(bug!(POISONED_MUTEX))
+                    .prompt_message(PromptMessage::Text(QRCODE_ERROR.to_string()))?;
             };
         }
 
@@ -206,7 +272,9 @@ pub trait Format {
                 let validator = MnemonicSetValidator {
                     word_lengths: [9, 24],
                 };
-                let [nonce_mnemonic, pubkey_mnemonic] = pm
+                let [nonce_mnemonic, pubkey_mnemonic] = prompt
+                    .lock()
+                    .expect(bug!(POISONED_MUTEX))
                     .prompt_validated_wordlist::<English, _>(
                         QRCODE_COULDNT_READ,
                         3,
@@ -237,7 +305,8 @@ pub trait Format {
         let shared_key = Aes256Gcm::new_from_slice(&hkdf_output)?;
 
         // decrypt a single shard and create the payload
-        let (share, threshold) = self.decrypt_one_shard(private_keys, &encrypted_messages)?;
+        let (share, threshold) =
+            self.decrypt_one_shard(private_keys, &encrypted_messages, prompt.clone())?;
         let mut payload = Vec::from(&share);
         payload.insert(0, HUNK_VERSION);
         payload.insert(1, threshold);
@@ -285,7 +354,10 @@ pub trait Format {
             let mut qrcode_data = our_pubkey_mnemonic.to_bytes();
             qrcode_data.extend(payload_mnemonic.as_bytes());
             if let Ok(qrcode) = qrencode(&smex::encode(&qrcode_data), ErrorCorrection::Highest) {
-                pm.prompt_message(PromptMessage::Text(
+                prompt
+                    .lock()
+                    .expect(bug!(POISONED_MUTEX))
+                    .prompt_message(PromptMessage::Text(
                         concat!(
                             "A QR code will be displayed after this prompt. ",
                             "Send the QR code back to the operator combining the shards. ",
@@ -293,11 +365,17 @@ pub trait Format {
                         )
                         .to_string(),
                     ))?;
-                pm.prompt_message(PromptMessage::Data(qrcode))?;
+                prompt
+                    .lock()
+                    .expect(bug!(POISONED_MUTEX))
+                    .prompt_message(PromptMessage::Data(qrcode))?;
             }
         }
 
-        pm.prompt_message(PromptMessage::Text(format!(
+        prompt
+            .lock()
+            .expect(bug!(POISONED_MUTEX))
+            .prompt_message(PromptMessage::Text(format!(
             "Upon request, these words should be sent: {our_pubkey_mnemonic} {payload_mnemonic}"
         )))?;
 

crates/keyfork-shard/src/lib.rs.orig

@@ -0,0 +1,617 @@
+#![doc = include_str!("../README.md")]
+#![allow(clippy::expect_fun_call)]
+
+use std::{
+    io::{stdin, stdout, Read, Write},
+    sync::{Arc, Mutex},
+};
+
+use aes_gcm::{
+    aead::{consts::U12, Aead, AeadCore, OsRng},
+    Aes256Gcm, KeyInit, Nonce,
+};
+use hkdf::Hkdf;
+<<<<<<< HEAD
+use keyfork_bug::{bug, POISONED_MUTEX};
+||||||| parent of 1b30b17 (keyfork-shard: begin work on (re)provisioning shardholder keys)
+=======
+use keyfork_derive_util::{DerivationIndex, DerivationPath};
+>>>>>>> 1b30b17 (keyfork-shard: begin work on (re)provisioning shardholder keys)
+use keyfork_mnemonic_util::{English, Mnemonic};
+use keyfork_prompt::{
+    validators::{mnemonic::MnemonicSetValidator, Validator},
+    Message as PromptMessage, PromptHandler, Terminal,
+};
+use sha2::Sha256;
+use sharks::{Share, Sharks};
+use x25519_dalek::{EphemeralSecret, PublicKey};
+
+// 256 bit share encrypted is 49 bytes, couple more bytes before we reach max size
+const ENC_LEN: u8 = 4 * 16;
+
+#[cfg(feature = "openpgp")]
+pub mod openpgp;
+
+/// A trait to specify where keys can be discovered from, such as a Rust-native type or a path on
+/// the filesystem that keys may be read from.
+pub trait KeyDiscovery<F: Format + ?Sized> {
+    /// Discover public keys for the associated format.
+    ///
+    /// # Errors
+    /// The method may return an error if public keys could not be loaded from the given discovery
+    /// mechanism. A discovery mechanism _must_ be able to detect public keys.
+    fn discover_public_keys(&self) -> Result<Vec<F::PublicKey>, F::Error>;
+
+    /// Discover private keys for the associated format.
+    ///
+    /// # Errors
+    /// The method may return an error if private keys could not be loaded from the given
+    /// discovery mechanism. Keys may exist off-system (such as with smartcards), in which case the
+    /// PrivateKeyData type of the asssociated format should be either `()` (if the keys may never
+    /// exist on-system) or an empty container (such as an empty Vec); in either case, this method
+    /// _must not_ return an error if keys are accessible but can't be transferred into memory.
+    fn discover_private_keys(&self) -> Result<F::PrivateKeyData, F::Error>;
+}
+
+/// A format to use for splitting and combining secrets.
+pub trait Format {
+    /// The error type returned from any failed operations.
+    type Error: std::error::Error + 'static;
+
+    /// A type encapsulating a single public key recipient.
+    type PublicKey;
+
+    /// A type encapsulating the private key recipients of shards.
+    type PrivateKeyData;
+
+    /// A type representing a Signer derived from the secret.
+    type SigningKey;
+
+    /// A type representing the parsed, but encrypted, Shard data.
+    type EncryptedData;
+
+    /// Provision hardware with a deterministic key based on a shardholder's DerivationIndex.
+    ///
+    /// The derivation path for provisioned shardholder keys is built using the following template:
+    /// `m / purpose ' / shard_index ' / shardholder_index '`.
+    ///
+    /// Purpose is defined by the Format, and can be a four-byte sequence transformed into a u32
+    /// using `u32::from_be_bytes(*purpose)`. For OpenPGP, for legacy reasons, this purpose is
+    /// "\x00pgp". The purpose can be _any_ sequence of four bytes so long as the _first_ byte is
+    /// not higher than 0x80 (meaning, all ASCII / 7-bit characters are allowed).
+    ///
+    /// The shard index is provided by Keyfork, and is equivalent to b"shrd".
+    ///
+    /// The shardholder index is how Keyfork is able to recreate keys for specific shardholders -
+    /// the only necessary information is which shardholder is not accounted for. Shardholders are
+    /// encouraged to mark hardware with the shardholder number so shardholders can verify their
+    /// index.
+    fn provision_shardholder_key(
+        &self,
+        derivation_path: DerivationPath,
+        seed: &[u8],
+    ) -> Result<(), Self::Error>;
+
+    /// Return a DerivationIndex for the Format.
+    ///
+    /// The derivation path for provisioned shardholder keys is built using the following template:
+    /// `m / purpose ' / shard_index ' / shardholder_index '`.
+    ///
+    /// Purpose is defined by the Format, and can be a four-byte sequence transformed into a u32
+    /// using `u32::from_be_bytes(*purpose)`. For OpenPGP, for legacy reasons, this purpose is
+    /// "\x00pgp". The purpose can be _any_ sequence of four bytes so long as the _first_ byte is
+    /// not higher than 0x80 (meaning, all ASCII / 7-bit characters are allowed).
+    fn purpose_derivation_index(&self) -> DerivationIndex;
+
+    /// Create a shardholder derivation path for the given format.
+    ///
+    /// The derivation path for provisioned shardholder keys is built using the following template:
+    /// `m / purpose ' / shard_index ' / shardholder_index '`.
+    fn create_derivation_path(&self, shardholder_index: DerivationIndex) -> DerivationPath {
+        let purpose = self.purpose_derivation_index();
+        let shard_index = DerivationIndex::new(u32::from_be_bytes(*b"shrd"), true).unwrap();
+        DerivationPath::default()
+            .chain_push(purpose)
+            .chain_push(shard_index)
+            .chain_push(shardholder_index)
+    }
+
+    /// Derive a signer
+    fn derive_signing_key(&self, seed: &[u8]) -> Self::SigningKey;
+
+    /// Format a header containing necessary metadata. Such metadata contains a version byte, a
+    /// threshold byte, a public version of the [`Format::SigningKey`], and the public keys used to
+    /// encrypt shards. The public keys must be kept _in order_ to the encrypted shards. Keyfork
+    /// will use the same key_data for both, ensuring an iteration of this method will match with
+    /// iterations in methods called later.
+    ///
+    /// # Errors
+    /// The method may return an error if encryption to any of the public keys fails.
+    fn format_encrypted_header(
+        &self,
+        signing_key: &Self::SigningKey,
+        key_data: &[Self::PublicKey],
+        threshold: u8,
+    ) -> Result<Self::EncryptedData, Self::Error>;
+
+    /// Format a shard encrypted to the given public key, signing with the private key.
+    ///
+    /// # Errors
+    /// The method may return an error if the public key used to encrypt the shard is unsuitable
+    /// for encryption, or if an error occurs while encrypting.
+    fn encrypt_shard(
+        &self,
+        shard: &[u8],
+        public_key: &Self::PublicKey,
+        signing_key: &mut Self::SigningKey,
+    ) -> Result<Self::EncryptedData, Self::Error>;
+
+    /// Parse the Shard file into a processable type.
+    ///
+    /// # Errors
+    /// The method may return an error if the Shard file could not be read from or if the Shard
+    /// file could not be properly parsed.
+    fn parse_shard_file(
+        &self,
+        shard_file: impl Read + Send + Sync,
+    ) -> Result<Vec<Self::EncryptedData>, Self::Error>;
+
+    /// Write the Shard data to a Shard file.
+    ///
+    /// # Errors
+    /// The method may return an error if the Shard data could not be properly serialized or if the
+    /// Shard file could not be written to.
+    fn format_shard_file(
+        &self,
+        encrypted_data: &[Self::EncryptedData],
+        shard_file: impl Write + Send + Sync,
+    ) -> Result<(), Self::Error>;
+
+    /// Decrypt shares and associated metadata from a readable input. For the current version of
+    /// Keyfork, the only associated metadata is a u8 representing the threshold to combine
+    /// secrets.
+    ///
+    /// # Errors
+    /// The method may return an error if the shardfile couldn't be read from, if all shards
+    /// could not be decrypted, or if a shard could not be parsed from the decrypted data.
+    fn decrypt_all_shards(
+        &self,
+        private_keys: Option<Self::PrivateKeyData>,
+        encrypted_messages: &[Self::EncryptedData],
+        prompt: Arc<Mutex<impl PromptHandler>>,
+    ) -> Result<(Vec<Share>, u8), Self::Error>;
+
+    /// Decrypt a single share and associated metadata from a reaable input. For the current
+    /// version of Keyfork, the only associated metadata is a u8 representing the threshold to
+    /// combine secrets.
+    ///
+    /// # Errors
+    /// The method may return an error if the shardfile couldn't be read from, if a shard could not
+    /// be decrypted, or if a shard could not be parsed from the decrypted data.
+    fn decrypt_one_shard(
+        &self,
+        private_keys: Option<Self::PrivateKeyData>,
+        encrypted_data: &[Self::EncryptedData],
+        prompt: Arc<Mutex<impl PromptHandler>>,
+    ) -> Result<(Share, u8), Self::Error>;
+
+    /// Decrypt multiple shares and combine them to recreate a secret.
+    ///
+    /// # Errors
+    /// The method may return an error if the shares can't be decrypted or if the shares can't
+    /// be combined into a secret.
+    fn decrypt_all_shards_to_secret(
+        &self,
+        private_key_discovery: Option<impl KeyDiscovery<Self>>,
+        reader: impl Read + Send + Sync,
+        prompt: impl PromptHandler,
+    ) -> Result<Vec<u8>, Box<dyn std::error::Error>> {
+        let private_keys = private_key_discovery
+            .map(|p| p.discover_private_keys())
+            .transpose()?;
+        let encrypted_messages = self.parse_shard_file(reader)?;
+        let (shares, threshold) = self.decrypt_all_shards(
+            private_keys,
+            &encrypted_messages,
+            Arc::new(Mutex::new(prompt)),
+        )?;
+
+        let secret = Sharks(threshold)
+            .recover(&shares)
+            .map_err(|e| SharksError::CombineShare(e.to_string()))?;
+
+        Ok(secret)
+    }
+
+    /// Establish an AES-256-GCM transport key using ECDH, decrypt a single shard, and encrypt the
+    /// shard to the AES key.
+    ///
+    /// # Errors
+    /// The method may return an error if a share can't be decrypted. The method will not return an
+    /// error if the camera is inaccessible or if a hardware error is encountered while scanning a
+    /// QR code; instead, a mnemonic prompt will be used.
+    fn decrypt_one_shard_for_transport(
+        &self,
+        private_key_discovery: Option<impl KeyDiscovery<Self>>,
+        reader: impl Read + Send + Sync,
+        prompt: impl PromptHandler,
+    ) -> Result<(), Box<dyn std::error::Error>> {
+        let prompt = Arc::new(Mutex::new(prompt));
+
+        // parse input
+        let private_keys = private_key_discovery
+            .map(|p| p.discover_private_keys())
+            .transpose()?;
+        let encrypted_messages = self.parse_shard_file(reader)?;
+
+        // establish AES-256-GCM key via ECDH
+        let mut nonce_data: Option<[u8; 12]> = None;
+        let mut pubkey_data: Option<[u8; 32]> = None;
+
+        // receive remote data via scanning QR code from camera
+        #[cfg(feature = "qrcode")]
+        {
+            prompt
+                .lock()
+                .expect(bug!(POISONED_MUTEX))
+                .prompt_message(PromptMessage::Text(QRCODE_PROMPT.to_string()))?;
+            if let Ok(Some(hex)) =
+                keyfork_qrcode::scan_camera(std::time::Duration::from_secs(30), 0)
+            {
+                let decoded_data = smex::decode(&hex)?;
+                nonce_data = Some(decoded_data[..12].try_into().map_err(|_| InvalidData)?);
+                pubkey_data = Some(decoded_data[12..].try_into().map_err(|_| InvalidData)?)
+            } else {
+                prompt
+                    .lock()
+                    .expect(bug!(POISONED_MUTEX))
+                    .prompt_message(PromptMessage::Text(QRCODE_ERROR.to_string()))?;
+            };
+        }
+
+        // if QR code scanning failed or was unavailable, read from a set of mnemonics
+        let (nonce, their_pubkey) = match (nonce_data, pubkey_data) {
+            (Some(nonce), Some(pubkey)) => (nonce, pubkey),
+            _ => {
+                let validator = MnemonicSetValidator {
+                    word_lengths: [9, 24],
+                };
+                let [nonce_mnemonic, pubkey_mnemonic] = prompt
+                    .lock()
+                    .expect(bug!(POISONED_MUTEX))
+                    .prompt_validated_wordlist::<English, _>(
+                        QRCODE_COULDNT_READ,
+                        3,
+                        validator.to_fn(),
+                    )?;
+
+                let nonce = nonce_mnemonic
+                    .as_bytes()
+                    .try_into()
+                    .map_err(|_| InvalidData)?;
+                let pubkey = pubkey_mnemonic
+                    .as_bytes()
+                    .try_into()
+                    .map_err(|_| InvalidData)?;
+                (nonce, pubkey)
+            }
+        };
+
+        // create our shared key
+        let our_key = EphemeralSecret::random();
+        let our_pubkey_mnemonic = Mnemonic::from_bytes(PublicKey::from(&our_key).as_bytes())?;
+        let shared_secret = our_key
+            .diffie_hellman(&PublicKey::from(their_pubkey))
+            .to_bytes();
+        let hkdf = Hkdf::<Sha256>::new(None, &shared_secret);
+        let mut hkdf_output = [0u8; 256 / 8];
+        hkdf.expand(&[], &mut hkdf_output)?;
+        let shared_key = Aes256Gcm::new_from_slice(&hkdf_output)?;
+
+        // decrypt a single shard and create the payload
+        let (share, threshold) =
+            self.decrypt_one_shard(private_keys, &encrypted_messages, prompt.clone())?;
+        let mut payload = Vec::from(&share);
+        payload.insert(0, HUNK_VERSION);
+        payload.insert(1, threshold);
+        assert!(
+            payload.len() <= ENC_LEN as usize,
+            "invalid share length (too long, max {ENC_LEN} bytes)"
+        );
+
+        // encrypt data
+        let nonce = Nonce::<U12>::from_slice(&nonce);
+        let payload_bytes = shared_key.encrypt(nonce, payload.as_slice())?;
+
+        // convert data to a static-size payload
+        // NOTE: Padding length is less than u8::MAX because ENC_LEN < u8::MAX
+        #[allow(clippy::assertions_on_constants)]
+        {
+            assert!(ENC_LEN < u8::MAX, "padding byte can be u8");
+        }
+        #[allow(clippy::cast_possible_truncation)]
+        let mut out_bytes = [payload_bytes.len() as u8; ENC_LEN as usize];
+        assert!(
+            payload_bytes.len() < out_bytes.len(),
+            "encrypted payload larger than acceptable limit"
+        );
+        out_bytes[..payload_bytes.len()].clone_from_slice(&payload_bytes);
+
+        // NOTE: This previously used a single repeated value as the padding byte, but resulted in
+        // difficulty when entering in prompts manually, as one's place could be lost due to
+        // repeated keywords. This is resolved below by having sequentially increasing numbers up to
+        // but not including the last byte.
+        #[allow(clippy::cast_possible_truncation)]
+        for (i, byte) in (out_bytes[payload_bytes.len()..(ENC_LEN as usize - 1)])
+            .iter_mut()
+            .enumerate()
+        {
+            *byte = (i % u8::MAX as usize) as u8;
+        }
+
+        // safety: size of out_bytes is constant and always % 4 == 0
+        let payload_mnemonic = unsafe { Mnemonic::from_raw_bytes(&out_bytes) };
+
+        #[cfg(feature = "qrcode")]
+        {
+            use keyfork_qrcode::{qrencode, ErrorCorrection};
+            let mut qrcode_data = our_pubkey_mnemonic.to_bytes();
+            qrcode_data.extend(payload_mnemonic.as_bytes());
+            if let Ok(qrcode) = qrencode(&smex::encode(&qrcode_data), ErrorCorrection::Highest) {
+                prompt
+                    .lock()
+                    .expect(bug!(POISONED_MUTEX))
+                    .prompt_message(PromptMessage::Text(
+                        concat!(
+                            "A QR code will be displayed after this prompt. ",
+                            "Send the QR code back to the operator combining the shards. ",
+                            "Nobody else should scan this QR code."
+                        )
+                        .to_string(),
+                    ))?;
+                prompt
+                    .lock()
+                    .expect(bug!(POISONED_MUTEX))
+                    .prompt_message(PromptMessage::Data(qrcode))?;
+            }
+        }
+
+        prompt
+            .lock()
+            .expect(bug!(POISONED_MUTEX))
+            .prompt_message(PromptMessage::Text(format!(
+            "Upon request, these words should be sent: {our_pubkey_mnemonic} {payload_mnemonic}"
+        )))?;
+
+        Ok(())
+    }
+
+    /// Split a secret into a shard for every shard in keys, with the given Shamir's Secret Sharing
+    /// threshold.
+    ///
+    /// # Errors
+    /// The method may return an error if the shares can't be encrypted.
+    fn shard_and_encrypt(
+        &self,
+        threshold: u8,
+        max: u8,
+        secret: &[u8],
+        public_key_discovery: impl KeyDiscovery<Self>,
+        writer: impl Write + Send + Sync,
+    ) -> Result<(), Box<dyn std::error::Error>> {
+        let mut signing_key = self.derive_signing_key(secret);
+
+        let sharks = Sharks(threshold);
+        let dealer = sharks.dealer(secret);
+
+        let public_keys = public_key_discovery.discover_public_keys()?;
+        assert!(
+            public_keys.len() < u8::MAX as usize,
+            "must have less than u8::MAX public keys"
+        );
+        assert_eq!(
+            max,
+            public_keys.len() as u8,
+            "max must be equal to amount of public keys"
+        );
+        let max = public_keys.len() as u8;
+        assert!(max >= threshold, "threshold must not exceed max keys");
+
+        let header = self.format_encrypted_header(&signing_key, &public_keys, threshold)?;
+        let mut messages = vec![header];
+        for (pk, share) in public_keys.iter().zip(dealer) {
+            let shard = Vec::from(&share);
+            messages.push(self.encrypt_shard(&shard, pk, &mut signing_key)?);
+        }
+
+        self.format_shard_file(&messages, writer)?;
+
+        Ok(())
+    }
+}
+
+/// Errors encountered while creating or combining shares using Shamir's Secret Sharing.
+#[derive(thiserror::Error, Debug)]
+pub enum SharksError {
+    /// A Shamir Share could not be created.
+    #[error("Error creating share: {0}")]
+    Share(String),
+
+    /// The Shamir shares could not be combined.
+    #[error("Error combining shares: {0}")]
+    CombineShare(String),
+}
+
+/// The mnemonic or QR code used to transport an encrypted shard did not store the correct amount
+/// of data.
+#[derive(thiserror::Error, Debug)]
+#[error("Mnemonic or QR code did not store enough data")]
+pub struct InvalidData;
+
+/// Decrypt hunk version 1:
+/// 1 byte: Version
+/// 1 byte: Threshold
+/// Data: &[u8]
+pub(crate) const HUNK_VERSION: u8 = 1;
+pub(crate) const HUNK_OFFSET: usize = 2;
+
+const QRCODE_PROMPT: &str = "Press enter, then present QR code to camera.";
+const QRCODE_TIMEOUT: u64 = 60; // One minute
+const QRCODE_COULDNT_READ: &str = "A QR code could not be scanned. Please enter their words: ";
+const QRCODE_ERROR: &str = "Unable to scan a QR code. Falling back to text entry.";
+
+/// Establish ECDH transport for remote operators, receive transport-encrypted shares, decrypt the
+/// shares, and combine them.
+///
+/// # Errors
+/// The function may error if:
+/// * Prompting for transport-encrypted shards fails.
+/// * Decrypting shards fails.
+/// * Combining shards fails.
+///
+/// # Panics
+/// The function may panic if it is given payloads generated using a version of Keyfork that is
+/// incompatible with the currently running version.
+pub fn remote_decrypt(w: &mut impl Write) -> Result<(), Box<dyn std::error::Error>> {
+    let mut pm = Terminal::new(stdin(), stdout())?;
+
+    let mut iter_count = None;
+    let mut shares = vec![];
+
+    let mut threshold = 0;
+    let mut iter = 0;
+
+    while iter_count.is_none() || iter_count.is_some_and(|i| i > 0) {
+        iter += 1;
+        let nonce = Aes256Gcm::generate_nonce(&mut OsRng);
+        let nonce_mnemonic = unsafe { Mnemonic::from_raw_bytes(nonce.as_slice()) };
+        let our_key = EphemeralSecret::random();
+        let key_mnemonic = Mnemonic::from_bytes(PublicKey::from(&our_key).as_bytes())?;
+
+        #[cfg(feature = "qrcode")]
+        {
+            use keyfork_qrcode::{qrencode, ErrorCorrection};
+            let mut qrcode_data = nonce_mnemonic.to_bytes();
+            qrcode_data.extend(key_mnemonic.as_bytes());
+            if let Ok(qrcode) = qrencode(&smex::encode(&qrcode_data), ErrorCorrection::Highest) {
+                pm.prompt_message(PromptMessage::Text(format!(
+                    concat!(
+                        "A QR code will be displayed after this prompt. ",
+                        "Send the QR code to only shardholder {iter}. ",
+                        "Nobody else should scan this QR code."
+                    ),
+                    iter = iter
+                )))?;
+                pm.prompt_message(PromptMessage::Data(qrcode))?;
+            }
+        }
+
+        pm.prompt_message(PromptMessage::Text(format!(
+            concat!(
+                "Upon request, these words should be sent to shardholder {iter}: ",
+                "{nonce_mnemonic} {key_mnemonic}"
+            ),
+            iter = iter,
+            nonce_mnemonic = nonce_mnemonic,
+            key_mnemonic = key_mnemonic,
+        )))?;
+
+        let mut pubkey_data: Option<[u8; 32]> = None;
+        let mut payload_data = None;
+
+        #[cfg(feature = "qrcode")]
+        {
+            pm.prompt_message(PromptMessage::Text(QRCODE_PROMPT.to_string()))?;
+            if let Ok(Some(hex)) =
+                keyfork_qrcode::scan_camera(std::time::Duration::from_secs(QRCODE_TIMEOUT), 0)
+            {
+                let decoded_data = smex::decode(&hex)?;
+                let _ = pubkey_data.insert(decoded_data[..32].try_into().map_err(|_| InvalidData)?);
+                let _ = payload_data.insert(decoded_data[32..].to_vec());
+            } else {
+                pm.prompt_message(PromptMessage::Text(QRCODE_ERROR.to_string()))?;
+            };
+        }
+
+        let (pubkey, payload) = match (pubkey_data, payload_data) {
+            (Some(pubkey), Some(payload)) => (pubkey, payload),
+            _ => {
+                let validator = MnemonicSetValidator {
+                    word_lengths: [24, 48],
+                };
+
+                let [pubkey_mnemonic, payload_mnemonic] = pm
+                    .prompt_validated_wordlist::<English, _>(
+                        QRCODE_COULDNT_READ,
+                        3,
+                        validator.to_fn(),
+                    )?;
+                let pubkey = pubkey_mnemonic
+                    .as_bytes()
+                    .try_into()
+                    .map_err(|_| InvalidData)?;
+                let payload = payload_mnemonic.to_bytes();
+                (pubkey, payload)
+            }
+        };
+
+        let shared_secret = our_key.diffie_hellman(&PublicKey::from(pubkey)).to_bytes();
+        let hkdf = Hkdf::<Sha256>::new(None, &shared_secret);
+        let mut hkdf_output = [0u8; 256 / 8];
+        hkdf.expand(&[], &mut hkdf_output)?;
+        let shared_key = Aes256Gcm::new_from_slice(&hkdf_output)?;
+
+        let payload =
+            shared_key.decrypt(&nonce, &payload[..payload[payload.len() - 1] as usize])?;
+        assert_eq!(HUNK_VERSION, payload[0], "Incompatible hunk version");
+
+        match &mut iter_count {
+            Some(n) => {
+                // Must be > 0 to start loop, can't go lower
+                *n -= 1;
+            }
+            None => {
+                // NOTE: Should always be >= 1, < 256 due to Shamir constraints
+                threshold = payload[1];
+                let _ = iter_count.insert(threshold - 1);
+            }
+        }
+
+        shares.push(payload[HUNK_OFFSET..].to_vec());
+    }
+
+    let shares = shares
+        .into_iter()
+        .map(|s| Share::try_from(s.as_slice()))
+        .collect::<Result<Vec<_>, &str>>()
+        .map_err(|e| SharksError::Share(e.to_string()))?;
+    let secret = Sharks(threshold)
+        .recover(&shares)
+        .map_err(|e| SharksError::CombineShare(e.to_string()))?;
+
+    /*
+     * Verification would take up too much size, mnemonic would be very large
+    let userid = UserID::from("keyfork-sss");
+    let kdr = DerivationRequest::new(
+        DerivationAlgorithm::Ed25519,
+        &DerivationPath::from_str("m/7366512'/0'")?,
+    )
+    .derive_with_master_seed(secret.to_vec())?;
+    let derived_cert = keyfork_derive_openpgp::derive(
+        kdr,
+        &[KeyFlags::empty().set_certification().set_signing()],
+        userid,
+    )?;
+
+    // NOTE: Signatures on certs will be different. Compare fingerprints instead.
+    let derived_fp = derived_cert.fingerprint();
+    let expected_fp = root_cert.fingerprint();
+    if derived_fp != expected_fp {
+        return Err(Error::InvalidSecret(derived_fp, expected_fp));
+    }
+    */
+
+    w.write_all(&secret)?;
+
+    Ok(())
+}

crates/keyfork-shard/src/openpgp.rs

@@ -1,16 +1,22 @@
 //! OpenPGP Shard functionality.
 
+#![allow(clippy::expect_fun_call)]
+
 use std::{
     collections::HashMap,
     io::{Read, Write},
+    marker::PhantomData,
     path::Path,
     str::FromStr,
+    sync::{Arc, Mutex},
 };
 
+use keyfork_bug::bug;
 use keyfork_derive_openpgp::{
-    derive_util::{DerivationPath, VariableLengthSeed},
+    derive_util::{DerivationIndex, DerivationPath, VariableLengthSeed},
     XPrv,
 };
+use keyfork_prompt::PromptHandler;
 use openpgp::{
     armor::{Kind, Writer},
     cert::{Cert, CertParser, ValidCert},
@@ -176,9 +182,18 @@ impl EncryptedMessage {
 }
 
 ///
-pub struct OpenPGP;
+pub struct OpenPGP<P: PromptHandler> {
+    p: PhantomData<P>,
+}
 
-impl OpenPGP {
+impl<P: PromptHandler> OpenPGP<P> {
+    #[allow(clippy::new_without_default, missing_docs)]
+    pub fn new() -> Self {
+        Self { p: PhantomData }
+    }
+}
+
+impl<P: PromptHandler> OpenPGP<P> {
     /// Read all OpenPGP certificates in a path and return a [`Vec`] of them. Certificates are read
     /// from a file, or from files one level deep in a directory.
     ///
@@ -209,28 +224,42 @@ impl OpenPGP {
     }
 }
 
-impl Format for OpenPGP {
+const METADATA_MESSAGE_MISSING: &str = "Metadata message was not found in parsed packets";
+
+impl<P: PromptHandler> Format for OpenPGP<P> {
     type Error = Error;
     type PublicKey = Cert;
     type PrivateKeyData = Vec<Cert>;
     type SigningKey = Cert;
     type EncryptedData = EncryptedMessage;
 
+    fn provision_shardholder_key(
+        &self,
+        derivation_path: DerivationPath,
+        seed: &[u8],
+    ) -> Result<(), Self::Error> {
+        todo!()
+    }
+
+    fn purpose_derivation_index(&self) -> DerivationIndex {
+        DerivationIndex::new(u32::from_be_bytes(*b"\x00pgp"), true).unwrap()
+    }
+
     /// Derive an OpenPGP Shard certificate from the given seed.
     fn derive_signing_key(&self, seed: &[u8]) -> Self::SigningKey {
         let seed = VariableLengthSeed::new(seed);
         // build cert to sign encrypted shares
         let userid = UserID::from("keyfork-sss");
-        let path = DerivationPath::from_str("m/7366512'/0'").expect("valid derivation path");
+        let path = DerivationPath::from_str("m/7366512'/0'").expect(bug!("valid derivation path"));
         let xprv = XPrv::new(seed)
             .derive_path(&path)
-            .expect("valid derivation");
+            .expect(bug!("valid derivation"));
         keyfork_derive_openpgp::derive(
             xprv,
             &[KeyFlags::empty().set_certification().set_signing()],
             &userid,
         )
-        .expect("valid cert creation")
+        .expect(bug!("valid cert creation"))
     }
 
     fn format_encrypted_header(
@@ -244,21 +273,26 @@ impl Format for OpenPGP {
         // Note: Sequoia does not export private keys on a Cert, only on a TSK
         signing_key
             .serialize(&mut pp)
-            .expect("serialize cert into bytes");
+            .expect(bug!("serialize cert into bytes"));
         for cert in key_data {
             cert.serialize(&mut pp)
-                .expect("serialize pubkey into bytes");
+                .expect(bug!("serialize pubkey into bytes"));
         }
 
         // verify packet pile
         let mut iter = openpgp::cert::CertParser::from_bytes(&pp[SHARD_METADATA_OFFSET..])
-            .expect("should have certs");
+            .expect(bug!("should have certs"));
-        let first_cert = iter.next().transpose().ok().flatten().expect("first cert");
+        let first_cert = iter
+            .next()
+            .transpose()
+            .ok()
+            .flatten()
+            .expect(bug!("first cert"));
         assert_eq!(signing_key, &first_cert);
 
         for (packet_cert, cert) in iter.zip(key_data) {
             assert_eq!(
-                &packet_cert.expect("parsed packet cert"),
+                &packet_cert.expect(bug!("parsed packet cert")),
                 cert,
                 "packet pile could not recreate cert: {}",
                 cert.fingerprint(),
@@ -371,7 +405,7 @@ impl Format for OpenPGP {
             .map_err(Error::Sequoia)?
             .into_iter()
             .next()
-            .expect("serialized message should be parseable");
+            .expect(bug!("serialized message should be parseable"));
 
         Ok(message)
     }
@@ -400,16 +434,20 @@ impl Format for OpenPGP {
         &self,
         private_keys: Option<Self::PrivateKeyData>,
         encrypted_data: &[Self::EncryptedData],
+        prompt: Arc<Mutex<impl PromptHandler>>,
     ) -> std::result::Result<(Vec<Share>, u8), Self::Error> {
         // Be as liberal as possible when decrypting.
         // We don't want to invalidate someone's keys just because the old sig expired.
         let policy = NullPolicy::new();
-        let mut keyring = Keyring::new(private_keys.unwrap_or_default())?;
+
-        let mut manager = SmartcardManager::new()?;
+        let mut keyring = Keyring::new(private_keys.unwrap_or_default(), prompt.clone())?;
+        let mut manager = SmartcardManager::new(prompt.clone())?;
 
         let mut encrypted_messages = encrypted_data.iter();
 
-        let metadata = encrypted_messages.next().expect("metdata");
+        let metadata = encrypted_messages
+            .next()
+            .expect(bug!(METADATA_MESSAGE_MISSING));
         let metadata_content = decrypt_metadata(metadata, &policy, &mut keyring, &mut manager)?;
 
         let (threshold, root_cert, certs) = decode_metadata_v1(&metadata_content)?;
@@ -457,14 +495,18 @@ impl Format for OpenPGP {
         &self,
         private_keys: Option<Self::PrivateKeyData>,
         encrypted_data: &[Self::EncryptedData],
+        prompt: Arc<Mutex<impl PromptHandler>>,
     ) -> std::result::Result<(Share, u8), Self::Error> {
         let policy = NullPolicy::new();
-        let mut keyring = Keyring::new(private_keys.unwrap_or_default())?;
+
-        let mut manager = SmartcardManager::new()?;
+        let mut keyring = Keyring::new(private_keys.unwrap_or_default(), prompt.clone())?;
+        let mut manager = SmartcardManager::new(prompt.clone())?;
 
         let mut encrypted_messages = encrypted_data.iter();
 
-        let metadata = encrypted_messages.next().expect("metadata");
+        let metadata = encrypted_messages
+            .next()
+            .expect(bug!(METADATA_MESSAGE_MISSING));
         let metadata_content = decrypt_metadata(metadata, &policy, &mut keyring, &mut manager)?;
 
         let (threshold, root_cert, certs) = decode_metadata_v1(&metadata_content)?;
@@ -499,22 +541,22 @@ impl Format for OpenPGP {
     }
 }
 
-impl KeyDiscovery<OpenPGP> for &Path {
+impl<P: PromptHandler> KeyDiscovery<OpenPGP<P>> for &Path {
-    fn discover_public_keys(&self) -> Result<Vec<<OpenPGP as Format>::PublicKey>> {
+    fn discover_public_keys(&self) -> Result<Vec<<OpenPGP<P> as Format>::PublicKey>> {
-        OpenPGP::discover_certs(self)
+        OpenPGP::<P>::discover_certs(self)
     }
 
-    fn discover_private_keys(&self) -> Result<<OpenPGP as Format>::PrivateKeyData> {
+    fn discover_private_keys(&self) -> Result<<OpenPGP<P> as Format>::PrivateKeyData> {
-        todo!()
+        OpenPGP::<P>::discover_certs(self)
     }
 }
 
-impl KeyDiscovery<OpenPGP> for &[Cert] {
+impl<P: PromptHandler> KeyDiscovery<OpenPGP<P>> for &[Cert] {
-    fn discover_public_keys(&self) -> Result<Vec<<OpenPGP as Format>::PublicKey>> {
+    fn discover_public_keys(&self) -> Result<Vec<<OpenPGP<P> as Format>::PublicKey>> {
         Ok(self.to_vec())
     }
 
-    fn discover_private_keys(&self) -> Result<<OpenPGP as Format>::PrivateKeyData> {
+    fn discover_private_keys(&self) -> Result<<OpenPGP<P> as Format>::PrivateKeyData> {
         Ok(self.to_vec())
     }
 }
@@ -575,12 +617,12 @@ fn decode_metadata_v1(buf: &[u8]) -> Result<(u8, Cert, Vec<Cert>)> {
 
 // NOTE: When using single-decryptor mechanism, use this method with `threshold = 1` to return a
 // single message.
-fn decrypt_with_manager(
+fn decrypt_with_manager<P: PromptHandler>(
     threshold: u8,
     messages: &mut HashMap<KeyID, EncryptedMessage>,
     certs: &[Cert],
     policy: &dyn Policy,
-    manager: &mut SmartcardManager,
+    manager: &mut SmartcardManager<P>,
 ) -> Result<HashMap<KeyID, Vec<u8>>> {
     let mut decrypted_messages = HashMap::new();
 
@@ -607,7 +649,12 @@ fn decrypt_with_manager(
 
         // Iterate over all fingerprints and use key_by_fingerprints to assoc with Enc. Message
         if let Some(fp) = manager.load_any_fingerprint(unused_fingerprints)? {
-            let cert_keyid = cert_by_fingerprint.get(&fp).unwrap().clone();
+            let cert_keyid = cert_by_fingerprint
+                .get(&fp)
+                .expect(bug!(
+                    "manager loaded fingerprint not from unused_fingerprints"
+                ))
+                .clone();
             if let Some(message) = messages.remove(&cert_keyid) {
                 let message = message.decrypt_with(policy, &mut *manager)?;
                 decrypted_messages.insert(cert_keyid, message);
@@ -620,11 +667,11 @@ fn decrypt_with_manager(
 
 // NOTE: When using single-decryptor mechanism, only a single key should be provided in Keyring to
 // decrypt messages with.
-fn decrypt_with_keyring(
+fn decrypt_with_keyring<P: PromptHandler>(
     messages: &mut HashMap<KeyID, EncryptedMessage>,
     certs: &[Cert],
     policy: &NullPolicy,
-    keyring: &mut Keyring,
+    keyring: &mut Keyring<P>,
 ) -> Result<HashMap<KeyID, Vec<u8>>, Error> {
     let mut decrypted_messages = HashMap::new();
 
@@ -654,11 +701,11 @@ fn decrypt_with_keyring(
     Ok(decrypted_messages)
 }
 
-fn decrypt_metadata(
+fn decrypt_metadata<P: PromptHandler>(
     message: &EncryptedMessage,
     policy: &NullPolicy,
-    keyring: &mut Keyring,
+    keyring: &mut Keyring<P>,
-    manager: &mut SmartcardManager,
+    manager: &mut SmartcardManager<P>,
 ) -> Result<Vec<u8>> {
     Ok(if keyring.is_empty() {
         manager.load_any_card()?;

crates/keyfork-shard/src/openpgp/keyring.rs

@@ -1,4 +1,9 @@
-use keyfork_prompt::{Error as PromptError, DefaultTerminal, default_terminal, PromptHandler};
+#![allow(clippy::expect_fun_call)]
+
+use std::sync::{Arc, Mutex};
+
+use keyfork_bug::{bug, POISONED_MUTEX};
+use keyfork_prompt::{Error as PromptError, PromptHandler};
 
 use super::openpgp::{
     self,
@@ -22,18 +27,18 @@ pub enum Error {
 
 pub type Result<T, E = Error> = std::result::Result<T, E>;
 
-pub struct Keyring {
+pub struct Keyring<P: PromptHandler> {
     full_certs: Vec<Cert>,
     root: Option<Cert>,
-    pm: DefaultTerminal,
+    pm: Arc<Mutex<P>>,
 }
 
-impl Keyring {
+impl<P: PromptHandler> Keyring<P> {
-    pub fn new(certs: impl AsRef<[Cert]>) -> Result<Self> {
+    pub fn new(certs: impl AsRef<[Cert]>, p: Arc<Mutex<P>>) -> Result<Self> {
         Ok(Self {
             full_certs: certs.as_ref().to_vec(),
             root: Default::default(),
-            pm: default_terminal()?,
+            pm: p,
         })
     }
 
@@ -57,7 +62,7 @@ impl Keyring {
     }
 }
 
-impl VerificationHelper for &mut Keyring {
+impl<P: PromptHandler> VerificationHelper for &mut Keyring<P> {
     fn get_certs(&mut self, ids: &[KeyHandle]) -> openpgp::Result<Vec<Cert>> {
         Ok(ids
             .iter()
@@ -93,7 +98,7 @@ impl VerificationHelper for &mut Keyring {
     }
 }
 
-impl DecryptionHelper for &mut Keyring {
+impl<P: PromptHandler> DecryptionHelper for &mut Keyring<P> {
     fn decrypt<D>(
         &mut self,
         pkesks: &[PKESK],
@@ -137,6 +142,8 @@ impl DecryptionHelper for &mut Keyring {
                         };
                         let passphrase = self
                             .pm
+                            .lock()
+                            .expect(bug!(POISONED_MUTEX))
                             .prompt_passphrase(&message)
                             .context("Decryption passphrase")?;
                         secret_key

crates/keyfork-shard/src/openpgp/smartcard.rs

@@ -1,9 +1,14 @@
-use std::collections::{HashMap, HashSet};
+#![allow(clippy::expect_fun_call)]
 
+use std::{
+    collections::{HashMap, HashSet},
+    sync::{Arc, Mutex},
+};
+
+use keyfork_bug::{bug, POISONED_MUTEX};
 use keyfork_prompt::{
-    default_terminal,
     validators::{PinValidator, Validator},
-    DefaultTerminal, Error as PromptError, Message, PromptHandler,
+    Error as PromptError, Message, PromptHandler,
 };
 
 use super::openpgp::{
@@ -66,19 +71,19 @@ fn format_name(input: impl AsRef<str>) -> String {
 }
 
 #[allow(clippy::module_name_repetitions)]
-pub struct SmartcardManager {
+pub struct SmartcardManager<P: PromptHandler> {
     current_card: Option<Card<Open>>,
     root: Option<Cert>,
-    pm: DefaultTerminal,
+    pm: Arc<Mutex<P>>,
     pin_cache: HashMap<Fingerprint, String>,
 }
 
-impl SmartcardManager {
+impl<P: PromptHandler> SmartcardManager<P> {
-    pub fn new() -> Result<Self> {
+    pub fn new(p: Arc<Mutex<P>>) -> Result<Self> {
         Ok(Self {
             current_card: None,
             root: None,
-            pm: default_terminal()?,
+            pm: p,
             pin_cache: Default::default(),
         })
     }
@@ -96,8 +101,12 @@ impl SmartcardManager {
             if let Some(c) = PcscBackend::cards(None)?.next().transpose()? {
                 break c;
             }
-            self.pm.prompt_message(Message::Text(
+            self.pm
-                "No smart card was found. Please plug in a smart card and press enter".to_string(),
+                .lock()
+                .expect(bug!(POISONED_MUTEX))
+                .prompt_message(Message::Text(
+                    "No smart card was found. Please plug in a smart card and press enter"
+                        .to_string(),
                 ))?;
         };
         let mut card = Card::<Open>::new(card_backend).map_err(Error::OpenSmartCard)?;
@@ -152,7 +161,10 @@ impl SmartcardManager {
                 }
             }
 
-            self.pm.prompt_message(Message::Text(
+            self.pm
+                .lock()
+                .expect(bug!(POISONED_MUTEX))
+                .prompt_message(Message::Text(
                     "Please plug in a smart card and press enter".to_string(),
                 ))?;
         }
@@ -161,7 +173,7 @@ impl SmartcardManager {
     }
 }
 
-impl VerificationHelper for &mut SmartcardManager {
+impl<P: PromptHandler> VerificationHelper for &mut SmartcardManager<P> {
     fn get_certs(&mut self, ids: &[openpgp::KeyHandle]) -> openpgp::Result<Vec<Cert>> {
         #[allow(clippy::flat_map_option)]
         Ok(ids
@@ -194,7 +206,7 @@ impl VerificationHelper for &mut SmartcardManager {
     }
 }
 
-impl DecryptionHelper for &mut SmartcardManager {
+impl<P: PromptHandler> DecryptionHelper for &mut SmartcardManager<P> {
     fn decrypt<D>(
         &mut self,
         pkesks: &[PKESK],
@@ -252,8 +264,10 @@ impl DecryptionHelper for &mut SmartcardManager {
             } else {
                 format!("Unlock card {card_id} ({cardholder_name})\n{rpea}: {attempts}\n\nPIN: ")
             };
-            let temp_pin = self
+            let temp_pin =
-                .pm
+                self.pm
+                    .lock()
+                    .expect(bug!(POISONED_MUTEX))
                     .prompt_validated_passphrase(&message, 3, &pin_validator)?;
             let verification_status = transaction.verify_user_pin(temp_pin.as_str().trim());
             match verification_status {
@@ -265,6 +279,8 @@ impl DecryptionHelper for &mut SmartcardManager {
                 // NOTE: This should not be hit, because of the above validator.
                 Err(CardError::CardStatus(StatusBytes::IncorrectParametersCommandDataField)) => {
                     self.pm
+                        .lock()
+                        .expect(bug!(POISONED_MUTEX))
                         .prompt_message(Message::Text("Invalid PIN length entered.".to_string()))?;
                 }
                 Err(_) => {}

crates/keyfork/Cargo.toml

@@ -23,16 +23,17 @@ sequoia-crypto-backend-openssl = ["sequoia-openpgp/crypto-openssl"]
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-keyforkd = { version = "0.1.0", path = "../daemon/keyforkd", features = ["tracing"] }
+keyfork-bin = { version = "0.1.0", path = "../util/keyfork-bin", registry = "distrust" }
-keyforkd-client = { version = "0.1.0", path = "../daemon/keyforkd-client", default-features = false, features = ["ed25519"] }
+keyforkd = { version = "0.1.0", path = "../daemon/keyforkd", features = ["tracing"], registry = "distrust" }
-keyfork-derive-openpgp = { version = "0.1.0", path = "../derive/keyfork-derive-openpgp" }
+keyforkd-client = { version = "0.1.0", path = "../daemon/keyforkd-client", default-features = false, features = ["ed25519"], registry = "distrust" }
-keyfork-derive-util = { version = "0.1.0", path = "../derive/keyfork-derive-util", default-features = false, features = ["ed25519"] }
+keyfork-derive-openpgp = { version = "0.1.0", path = "../derive/keyfork-derive-openpgp", registry = "distrust" }
-keyfork-entropy = { version = "0.1.0", path = "../util/keyfork-entropy" }
+keyfork-derive-util = { version = "0.1.0", path = "../derive/keyfork-derive-util", default-features = false, features = ["ed25519"], registry = "distrust" }
-keyfork-mnemonic-util = { version = "0.1.0", path = "../util/keyfork-mnemonic-util" }
+keyfork-entropy = { version = "0.1.0", path = "../util/keyfork-entropy", registry = "distrust" }
-keyfork-prompt = { version = "0.1.0", path = "../util/keyfork-prompt" }
+keyfork-mnemonic-util = { version = "0.2.0", path = "../util/keyfork-mnemonic-util", registry = "distrust" }
-keyfork-qrcode = { version = "0.1.0", path = "../qrcode/keyfork-qrcode", default-features = false }
+keyfork-prompt = { version = "0.1.0", path = "../util/keyfork-prompt", registry = "distrust" }
-keyfork-shard = { version = "0.1.0", path = "../keyfork-shard", default-features = false, features = ["openpgp", "openpgp-card", "qrcode"] }
+keyfork-qrcode = { version = "0.1.0", path = "../qrcode/keyfork-qrcode", default-features = false, registry = "distrust" }
-smex = { version = "0.1.0", path = "../util/smex" }
+keyfork-shard = { version = "0.1.0", path = "../keyfork-shard", default-features = false, features = ["openpgp", "openpgp-card", "qrcode"], registry = "distrust" }
+smex = { version = "0.1.0", path = "../util/smex", registry = "distrust" }
 
 clap = { version = "4.4.2", features = ["derive", "env", "wrap_help"] }
 thiserror = "1.0.48"
@@ -43,4 +44,3 @@ openpgp-card-sequoia = { version = "0.2.0", default-features = false }
 openpgp-card = "0.4.1"
 clap_complete = { version = "4.4.6", optional = true }
 sequoia-openpgp = { version = "1.17.0", default-features = false, features = ["compression"] }
-keyfork-bin = { version = "0.1.0", path = "../util/keyfork-bin" }

crates/keyfork/src/cli/recover.rs

@@ -3,6 +3,7 @@ use clap::{Parser, Subcommand};
 use std::path::PathBuf;
 
 use keyfork_mnemonic_util::{English, Mnemonic};
+use keyfork_prompt::{default_terminal, DefaultTerminal};
 use keyfork_shard::{remote_decrypt, Format};
 
 type Result<T, E = Box<dyn std::error::Error>> = std::result::Result<T, E>;
@@ -34,10 +35,14 @@ impl RecoverSubcommands {
             } => {
                 let content = std::fs::read_to_string(shard_file)?;
                 if content.contains("BEGIN PGP MESSAGE") {
-                    let openpgp = keyfork_shard::openpgp::OpenPGP;
+                    let openpgp = keyfork_shard::openpgp::OpenPGP::<DefaultTerminal>::new();
+                    let prompt_handler = default_terminal()?;
                     // TODO: remove .clone() by making handle() consume self
-                    let seed = openpgp
+                    let seed = openpgp.decrypt_all_shards_to_secret(
-                        .decrypt_all_shards_to_secret(key_discovery.as_deref(), content.as_bytes())?;
+                        key_discovery.as_deref(),
+                        content.as_bytes(),
+                        prompt_handler,
+                    )?;
                     Ok(seed)
                 } else {
                     panic!("unknown format of shard file");
@@ -50,7 +55,6 @@ impl RecoverSubcommands {
             }
             RecoverSubcommands::Mnemonic {} => {
                 use keyfork_prompt::{
-                    default_terminal,
                     validators::{
                         mnemonic::{MnemonicChoiceValidator, WordLength},
                         Validator,

crates/keyfork/src/cli/shard.rs

@@ -1,5 +1,6 @@
 use super::Keyfork;
 use clap::{builder::PossibleValue, Parser, Subcommand, ValueEnum};
+use keyfork_prompt::{default_terminal, DefaultTerminal};
 use keyfork_shard::Format as _;
 use std::{
     io::{stdin, stdout, Read, Write},
@@ -63,7 +64,7 @@ impl ShardExec for OpenPGP {
         secret: &[u8],
         output: &mut (impl Write + Send + Sync),
     ) -> Result<(), Box<dyn std::error::Error>> {
-        let opgp = keyfork_shard::openpgp::OpenPGP;
+        let opgp = keyfork_shard::openpgp::OpenPGP::<DefaultTerminal>::new();
         opgp.shard_and_encrypt(threshold, max, secret, key_discovery, output)
     }
 
@@ -72,10 +73,10 @@ impl ShardExec for OpenPGP {
         key_discovery: Option<&Path>,
         input: impl Read + Send + Sync,
         output: &mut impl Write,
-    ) -> Result<(), Box<dyn std::error::Error>>
+    ) -> Result<(), Box<dyn std::error::Error>> {
-    {
+        let openpgp = keyfork_shard::openpgp::OpenPGP::<DefaultTerminal>::new();
-        let openpgp = keyfork_shard::openpgp::OpenPGP;
+        let prompt = default_terminal()?;
-        let bytes = openpgp.decrypt_all_shards_to_secret(key_discovery, input)?;
+        let bytes = openpgp.decrypt_all_shards_to_secret(key_discovery, input, prompt)?;
         write!(output, "{}", smex::encode(bytes))?;
 
         Ok(())
@@ -85,10 +86,10 @@ impl ShardExec for OpenPGP {
         &self,
         key_discovery: Option<&Path>,
         input: impl Read + Send + Sync,
-    ) -> Result<(), Box<dyn std::error::Error>>
+    ) -> Result<(), Box<dyn std::error::Error>> {
-    {
+        let openpgp = keyfork_shard::openpgp::OpenPGP::<DefaultTerminal>::new();
-        let openpgp = keyfork_shard::openpgp::OpenPGP;
+        let prompt = default_terminal()?;
-        openpgp.decrypt_one_shard_for_transport(key_discovery, input)?;
+        openpgp.decrypt_one_shard_for_transport(key_discovery, input, prompt)?;
         Ok(())
     }
 }

crates/keyfork/src/cli/wizard.rs

@@ -12,7 +12,7 @@ use keyfork_derive_openpgp::{
 use keyfork_derive_util::{DerivationIndex, DerivationPath};
 use keyfork_prompt::{
     validators::{PinValidator, Validator},
-    Message, PromptHandler, Terminal,
+    Message, PromptHandler, DefaultTerminal, default_terminal
 };
 
 use keyfork_shard::{Format, openpgp::OpenPGP};
@@ -105,7 +105,7 @@ fn generate_shard_secret(
     output_file: &Option<PathBuf>,
 ) -> Result<()> {
     let seed = keyfork_entropy::generate_entropy_of_const_size::<{256 / 8}>()?;
-    let mut pm = Terminal::new(std::io::stdin(), std::io::stderr())?;
+    let mut pm = default_terminal()?;
     let mut certs = vec![];
     let mut seen_cards: HashSet<String> = HashSet::new();
     let stdout = std::io::stdout();
@@ -165,7 +165,7 @@ fn generate_shard_secret(
         certs.push(cert);
     }
 
-    let opgp = OpenPGP;
+    let opgp = OpenPGP::<DefaultTerminal>::new();
 
     if let Some(output_file) = output_file {
         let output = File::create(output_file)?;

crates/qrcode/keyfork-qrcode/Cargo.toml

@@ -8,14 +8,15 @@ license = "MIT"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [features]
-default = []
+default = ["bin"]
 bin = ["decode-backend-rqrr"]
 decode-backend-rqrr = ["dep:rqrr"]
 decode-backend-zbar = ["dep:keyfork-zbar"]
 
 [dependencies]
+keyfork-bug = { version = "0.1.0", path = "../../util/keyfork-bug", registry = "distrust" }
+keyfork-zbar = { version = "0.1.0", path = "../keyfork-zbar", optional = true, registry = "distrust" }
 image = { version = "0.24.7", default-features = false, features = ["jpeg"] }
-keyfork-zbar = { version = "0.1.0", path = "../keyfork-zbar", optional = true }
 rqrr = { version = "0.6.0", optional = true }
 thiserror = "1.0.56"
 v4l = "0.14.0"

crates/qrcode/keyfork-qrcode/src/lib.rs

@@ -1,5 +1,7 @@
 //! Encoding and decoding QR codes.
 
+use keyfork_bug as bug;
+
 use image::io::Reader as ImageReader;
 use std::{
     io::{Cursor, Write},
@@ -98,11 +100,13 @@ pub fn qrencode(
     Ok(result)
 }
 
+const VIDEO_FORMAT_READ_ERROR: &str = "Failed to read video device format";
+
 /// Continuously scan the `index`-th camera for a QR code.
 #[cfg(feature = "decode-backend-rqrr")]
 pub fn scan_camera(timeout: Duration, index: usize) -> Result<Option<String>, QRCodeScanError> {
     let device = Device::new(index)?;
-    let mut fmt = device.format().expect("Failed to read format");
+    let mut fmt = device.format().unwrap_or_else(bug::panic!(VIDEO_FORMAT_READ_ERROR));
     fmt.fourcc = FourCC::new(b"MPG1");
     device.set_format(&fmt)?;
     let mut stream = Stream::with_buffers(&device, Type::VideoCapture, 4)?;
@@ -133,7 +137,7 @@ pub fn scan_camera(timeout: Duration, index: usize) -> Result<Option<String>, QR
 #[cfg(feature = "decode-backend-zbar")]
 pub fn scan_camera(timeout: Duration, index: usize) -> Result<Option<String>, QRCodeScanError> {
     let device = Device::new(index)?;
-    let mut fmt = device.format().expect("Failed to read format");
+    let mut fmt = device.format().unwrap_or_else(bug::panic!(VIDEO_FORMAT_READ_ERROR));
     fmt.fourcc = FourCC::new(b"MPG1");
     device.set_format(&fmt)?;
     let mut stream = Stream::with_buffers(&device, Type::VideoCapture, 4)?;

crates/qrcode/keyfork-zbar/Cargo.toml

@@ -12,8 +12,8 @@ default = ["image"]
 image = ["dep:image"]
 
 [dependencies]
+keyfork-zbar-sys = { version = "0.1.0", path = "../keyfork-zbar-sys", registry = "distrust" }
 image = { version = "0.24.7", default-features = false, optional = true }
-keyfork-zbar-sys = { version = "0.1.0", path = "../keyfork-zbar-sys" }
 thiserror = "1.0.56"
 
 [dev-dependencies]

crates/util/keyfork-bin/Cargo.toml

@@ -2,6 +2,7 @@
 name = "keyfork-bin"
 version = "0.1.0"
 edition = "2021"
+license = "MIT"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 

crates/util/keyfork-bug/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "keyfork-bug"
+version = "0.1.0"
+edition = "2021"
+license = "MIT"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

crates/util/keyfork-bug/src/lib.rs

@@ -0,0 +1,108 @@
+//! Keyfork Bug Reporting Utilities.
+//!
+//! # Examples
+//!
+//! ```rust
+//! use std::{fs::File, io::Write};
+//! use keyfork_bug as bug;
+//!
+//! let option = Some("hello world!");
+//! let value = option.expect(bug::bug!("missing str value!"));
+//!
+//! let mut output_file = File::create("/dev/null").expect(bug::bug!("can't open /dev/null"));
+//! output_file
+//!     .write_all(value.as_bytes())
+//!     .unwrap_or_else(bug::panic!("Can't write to file: {}", value));
+//! ```
+//!
+//! ```rust,should_panic
+//! use std::fs::File;
+//! use keyfork_bug as bug;
+//!
+//! let mut output_file = File::open("/dev/nukk").expect(bug::bug!("can't open /dev/null"));
+//! ```
+
+/// The mutex was poisoned and is unusable.
+pub const POISONED_MUTEX: &str = "The mutex was poisoned and is unusable";
+
+/// Automatically generate a bug report message for Keyfork. This macro is intended to use when
+/// using `Result::expect()` or `Option::expect()` to retrieve information about the callsite where
+/// the bug was located.
+///
+/// # Examples
+/// ```rust
+/// use keyfork_bug::bug;
+///
+/// let option = Some(0u32);
+/// let value = option.expect(bug!("missing u32 value!"));
+/// ```
+///
+/// ```rust
+/// use keyfork_bug::bug;
+///
+/// let error_message = "This is a really long error message that should not be in the macro.";
+/// let option = Some(0u32);
+/// let value = option.expect(bug!(error_message));
+/// ```
+///
+/// ```rust,should_panic
+/// use keyfork_bug::bug;
+///
+/// let option: Option<u32> = None;
+/// let value = option.expect(bug!("missing u32 value!"));
+/// ```
+#[macro_export]
+macro_rules! bug {
+    ($input:literal) => {
+        concat!(
+            "Keyfork encountered a BUG at: [",
+            file!(),
+            ":",
+            line!(),
+            ":",
+            column!(),
+            "]: ",
+            $input,
+            "\n\nReport this bug to <team@distrust.co>, this behavior is unexpected!"
+        )
+    };
+    ($input:ident) => {
+        format!(
+            concat!("Keyfork encountered a BUG at: [{file}:{line}:{column}]: {input}\n\n",
+                    "Report this bug to <team@distrust.co>, this behavior is unexpected!"
+               ),
+            file=file!(),
+            line=line!(),
+            column=column!(),
+            input=$input,
+        ).as_str()
+    };
+    ($($arg:tt)*) => {{
+        let message = format!($($arg)*);
+        $crate::bug!(message)
+    }};
+}
+
+/// Return a closure that, when called, panics with a bug report message for Keyfork. Returning a
+/// closure can help handle the `clippy::expect_fun_call` lint. The closure accepts an error
+/// argument, so it is suitable for being used with [`Result`] types instead of [`Option`] types.
+///
+/// # Examples
+/// ```rust
+/// use std::fs::File;
+/// use keyfork_bug as bug;
+///
+/// let file = File::open("/dev/null").unwrap_or_else(bug::panic!("couldn't open /dev/null"));
+/// ```
+#[macro_export]
+macro_rules! panic {
+    ($input:literal) => { |e| {
+        std::panic!("{}\n{}", $crate::bug!($input), e)
+    }};
+    ($input:ident) => { |e| {
+        std::panic!("{}\n{}", $crate::bug!($input), e)
+    }};
+    ($($arg:tt)*) => { |e| {
+        std::panic!("{}\n{}", $crate::bug!($($arg)*), e)
+    }};
+}

crates/util/keyfork-entropy/Cargo.toml

@@ -11,4 +11,5 @@ default = ["bin"]
 bin = ["smex"]
 
 [dependencies]
-smex = { version = "0.1.0", path = "../smex", optional = true }
+keyfork-bug = { version = "0.1.0", path = "../keyfork-bug", registry = "distrust" }
+smex = { version = "0.1.0", path = "../smex", optional = true, registry = "distrust" }

crates/util/keyfork-entropy/src/lib.rs

@@ -1,5 +1,7 @@
 //! Utilities for reading entropy from secure sources.
 
+use keyfork_bug::bug;
+
 use std::{
     fs::{read_dir, read_to_string, File},
     io::Read,
@@ -9,15 +11,16 @@ static WARNING_LINKS: [&str; 1] =
     ["https://lore.kernel.org/lkml/20211223141113.1240679-2-Jason@zx2c4.com/"];
 
 fn ensure_safe_kernel_version() {
-    let kernel_version = read_to_string("/proc/version").expect("/proc/version");
+    let kernel_version =
+        read_to_string("/proc/version").expect(bug!("Unable to open file: /proc/version"));
     let v = kernel_version
         .split(' ')
         .nth(2)
-        .expect("Unable to parse kernel version")
+        .expect(bug!("Unable to parse kernel version"))
         .split('.')
         .take(2)
         .map(str::parse)
-        .map(|x| x.expect("Unable to parse kernel version number"))
+        .map(|x| x.expect(bug!("Unable to parse kernel version number")))
         .collect::<Vec<u32>>();
     let [major, minor, ..] = v.as_slice() else {
         panic!("Unable to determine major and minor: {kernel_version}");
@@ -30,22 +33,23 @@ fn ensure_safe_kernel_version() {
 }
 
 fn ensure_offline() {
-    let paths = read_dir("/sys/class/net").expect("Unable to read network interfaces");
+    let paths = read_dir("/sys/class/net").expect(bug!("Unable to read network interfaces"));
     for entry in paths {
-        let mut path = entry.expect("Unable to read directory entry").path();
+        let mut path = entry.expect(bug!("Unable to read directory entry")).path();
         if path
             .as_os_str()
             .to_str()
-            .expect("Unable to decode UTF-8 filepath")
+            .expect(bug!("Unable to decode UTF-8 filepath"))
             .split('/')
             .last()
-            .expect("No data in file path")
+            .expect(bug!("No data in file path"))
             == "lo"
         {
             continue;
         }
         path.push("operstate");
-        let isup = read_to_string(&path).expect("Unable to read operstate of network interfaces");
+        let isup =
+            read_to_string(&path).expect(bug!("Unable to read operstate of network interfaces"));
         assert_ne!(isup.trim(), "up", "No network interfaces should be up");
     }
 }

crates/util/keyfork-mnemonic-util/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "keyfork-mnemonic-util"
-version = "0.1.0"
+version = "0.2.0"
 description = "Utilities to generate and manage seeds based on BIP-0039 mnemonics."
 repository = "https://git.distrust.co/public/keyfork"
 edition = "2021"
@@ -11,12 +11,12 @@ default = ["bin"]
 bin = ["smex"]
 
 [dependencies]
-# Included in rust
+smex = { version = "0.1.0", path = "../smex", optional = true, registry = "distrust" }
-sha2 = "0.10.7"
+keyfork-bug = { version = "0.1.0", path = "../keyfork-bug", registry = "distrust" }
 
+sha2 = "0.10.7"
 hmac = "0.12.1"
 pbkdf2 = "0.12.2"
-smex = { version = "0.1.0", path = "../smex", optional = true }
 
 [dev-dependencies]
 bip39 = "2.0.0"

crates/util/keyfork-mnemonic-util/src/lib.rs

@@ -48,13 +48,9 @@
 //! let new_mnemonic = Mnemonic::from_str(&mnemonic_text).unwrap();
 //! ```
 
-use std::{
+use std::{error::Error, fmt::Display, marker::PhantomData, str::FromStr, sync::OnceLock};
-    error::Error,
+
-    fmt::Display,
+use keyfork_bug::bug;
-    str::FromStr,
-    sync::OnceLock,
-    marker::PhantomData,
-};
 
 use hmac::Hmac;
 use pbkdf2::pbkdf2;
@@ -115,12 +111,11 @@ impl Wordlist for English {
     fn get_singleton<'a>() -> &'a Self {
         ENGLISH.get_or_init(|| {
             let wordlist_file = include_str!("data/wordlist.txt");
-            let mut words = wordlist_file
+            let mut words = wordlist_file.lines().skip(1).map(|x| x.trim().to_string());
-                .lines()
-                .skip(1)
-                .map(|x| x.trim().to_string());
             English {
-                words: std::array::from_fn(|_| words.next().expect("wordlist has 2048 words")),
+                words: std::array::from_fn(|_| {
+                    words.next().expect(bug!("wordlist {} should have 2048 words"))
+                }),
             }
         })
     }
@@ -247,7 +242,10 @@ where
             }
         }
 
-        Ok(MnemonicBase { data, marker: PhantomData })
+        Ok(MnemonicBase {
+            data,
+            marker: PhantomData,
+        })
     }
 }
 
@@ -390,7 +388,7 @@ where
         let mnemonic = self.to_string();
         let salt = ["mnemonic", passphrase.unwrap_or("")].join("");
         pbkdf2::<Hmac<Sha512>>(mnemonic.as_bytes(), salt.as_bytes(), 2048, &mut seed)
-            .expect("HmacSha512 InvalidLength should be infallible");
+            .expect(bug!("HmacSha512 InvalidLength should be infallible"));
         seed.to_vec()
     }
 
@@ -415,13 +413,16 @@ where
         }
 
         // TODO: find a way to not have to collect to vec
-        bits.chunks_exact(11).peekable().map(|chunk| {
+        bits.chunks_exact(11)
+            .peekable()
+            .map(|chunk| {
                 let mut num = 0usize;
                 for i in 0..11 {
                     num += usize::from(chunk[10 - i]) << i;
                 }
                 num
-        }).collect()
+            })
+            .collect()
     }
 }
 

crates/util/keyfork-prompt/Cargo.toml

@@ -13,6 +13,7 @@ default = ["mnemonic"]
 mnemonic = ["keyfork-mnemonic-util"]
 
 [dependencies]
-keyfork-crossterm = { version = "0.27.1", path = "../keyfork-crossterm", default-features = false, features = ["use-dev-tty", "events", "bracketed-paste"] }
+keyfork-bug = { version = "0.1.0", path = "../keyfork-bug", registry = "distrust" }
-keyfork-mnemonic-util = { version = "0.1.0", path = "../keyfork-mnemonic-util", optional = true }
+keyfork-crossterm = { version = "0.27.1", path = "../keyfork-crossterm", default-features = false, features = ["use-dev-tty", "events", "bracketed-paste"], registry = "distrust" }
+keyfork-mnemonic-util = { version = "0.2.0", path = "../keyfork-mnemonic-util", optional = true, registry = "distrust" }
 thiserror = "1.0.51"

crates/util/keyfork-prompt/src/terminal.rs

@@ -13,6 +13,8 @@ use keyfork_crossterm::{
     ExecutableCommand, QueueableCommand,
 };
 
+use keyfork_bug::bug;
+
 use crate::{Error, Message, PromptHandler, Wordlist};
 
 #[allow(missing_docs)]
@@ -120,9 +122,15 @@ where
     W: Write + AsRawFd,
 {
     fn drop(&mut self) {
-        self.write.execute(DisableBracketedPaste).unwrap();
+        self.write
-        self.write.execute(LeaveAlternateScreen).unwrap();
+            .execute(DisableBracketedPaste)
-        self.terminal.disable_raw_mode().unwrap();
+            .expect(bug!("can't restore bracketed paste"));
+        self.write
+            .execute(LeaveAlternateScreen)
+            .expect(bug!("can't leave alternate screen"));
+        self.terminal
+            .disable_raw_mode()
+            .expect(bug!("can't disable raw mode"));
     }
 }
 
@@ -286,6 +294,20 @@ where
                     }
                     KeyCode::Char(c) => {
                         input.push(c);
+                        let entry_mode = std::env::var("KEYFORK_PROMPT_MNEMONIC_MODE");
+                        if entry_mode.is_ok_and(|mode| mode.to_ascii_lowercase() == "steel") {
+                            let word = input.split_whitespace().next_back().map(ToOwned::to_owned);
+                            if let Some(steel_word) = word {
+                                if steel_word.len() >= 4 {
+                                    for word in words.iter().filter(|word| word.len() >= 4) {
+                                        if word[..4] == steel_word {
+                                            input.push_str(&word[4..]);
+                                            input.push(' ');
+                                        }
+                                    }
+                                }
+                            }
+                        }
                     }
                     _ => (),
                 },

crates/util/keyfork-prompt/src/validators.rs

@@ -80,6 +80,7 @@ pub mod mnemonic {
     use super::Validator;
 
     use keyfork_mnemonic_util::{Mnemonic, MnemonicFromStrError};
+    use keyfork_bug::bug;
 
     /// A mnemonic could not be validated from the given input.
     #[derive(thiserror::Error, Debug)]
@@ -237,7 +238,7 @@ pub mod mnemonic {
 
                 Ok(output
                     .try_into()
-                    .expect("vec with capacity of const N was not filled"))
+                    .expect(bug!("vec with capacity of const N was not filled")))
             })
         }
     }

crates/util/keyfork-slip10-test-data/Cargo.toml

@@ -5,4 +5,4 @@ edition = "2021"
 license = "MIT"
 
 [dependencies]
-smex = { version = "0.1.0", path = "../smex" }
+smex = { version = "0.1.0", path = "../smex", registry = "distrust" }