keyfork-shard: further improve error handling, add multiline prompt and PIN retry detection

This commit is contained in:
Ryan Heywood 2023-11-05 16:21:54 -06:00
parent baa289ce62
commit fa61d31f3f
Signed by: ryan
GPG Key ID: 8E401478A3FBEF72
3 changed files with 115 additions and 62 deletions

View File

@ -52,10 +52,10 @@ pub enum Error {
SequoiaIo(#[source] std::io::Error), SequoiaIo(#[source] std::io::Error),
#[error("Keyring error: {0}")] #[error("Keyring error: {0}")]
Keyring(#[from] keyring::KeyringError), Keyring(#[from] keyring::Error),
#[error("Smartcard error: {0}")] #[error("Smartcard error: {0}")]
Smartcard(#[from] smartcard::SmartcardError), Smartcard(#[from] smartcard::Error),
#[error("IO error: {0}")] #[error("IO error: {0}")]
Io(#[source] std::io::Error), Io(#[source] std::io::Error),

View File

@ -9,18 +9,20 @@ use super::openpgp::{
KeyHandle, KeyID, KeyHandle, KeyID,
}; };
use crate::prompt_manager::{PromptManager, PinentryError}; use crate::prompt_manager::{PinentryError, PromptManager};
use anyhow::Context;
#[derive(thiserror::Error, Debug)] #[derive(thiserror::Error, Debug)]
pub enum KeyringError { pub enum Error {
#[error("Secret key was not found")] #[error("Secret key was not found")]
SecretKeyNotFound, SecretKeyNotFound,
#[error("Prompt failed: {0}")] #[error("Prompt failed: {0}")]
Prompt(#[from] PinentryError) Prompt(#[from] PinentryError),
} }
pub type Result<T, E = KeyringError> = std::result::Result<T, E>; pub type Result<T, E = Error> = std::result::Result<T, E>;
pub struct Keyring { pub struct Keyring {
full_certs: Vec<Cert>, full_certs: Vec<Cert>,
@ -89,8 +91,9 @@ impl VerificationHelper for &mut Keyring {
MessageLayer::SignatureGroup { results } => { MessageLayer::SignatureGroup { results } => {
for result in results { for result in results {
if let Err(e) = result { if let Err(e) = result {
// FIXME: anyhow leak // FIXME: anyhow leak: VerificationError impl std::error::Error
return Err(anyhow::anyhow!(e.to_string())); // return Err(e.context("Invalid signature"));
return Err(anyhow::anyhow!("Invalid signature: {e}"));
} }
} }
} }
@ -121,7 +124,9 @@ impl DecryptionHelper for &mut Keyring {
.next() .next()
.map(|userid| userid.userid().name().transpose()) .map(|userid| userid.userid().name().transpose())
.flatten() .flatten()
.transpose()?; .transpose()
.ok()
.flatten();
for key in cert for key in cert
.keys() .keys()
.with_policy(&null, None) .with_policy(&null, None)
@ -130,7 +135,9 @@ impl DecryptionHelper for &mut Keyring {
{ {
let secret_key = key.key().clone(); let secret_key = key.key().clone();
let mut keypair = if secret_key.has_unencrypted_secret() { let mut keypair = if secret_key.has_unencrypted_secret() {
secret_key.into_keypair()? secret_key
.into_keypair()
.context("Has unencrypted secret")?
} else { } else {
let message = if let Some(name) = name.as_ref() { let message = if let Some(name) = name.as_ref() {
format!("Decryption key for: {} ({name})", secret_key.keyid()) format!("Decryption key for: {} ({name})", secret_key.keyid())
@ -139,10 +146,13 @@ impl DecryptionHelper for &mut Keyring {
}; };
let passphrase = self let passphrase = self
.pm .pm
.prompt_passphrase("Decryption passphrase", message)?; .prompt_passphrase("Decryption passphrase", message)
let key = secret_key .context("Decryption passphrase")?;
.decrypt_secret(&passphrase.expose_secret().as_str().into())?; secret_key
key.into_keypair()? .decrypt_secret(&passphrase.expose_secret().as_str().into())
.context("has_unencrypted_secret is false, could not decrypt secret")?
.into_keypair()
.context("just-decrypted key")?
}; };
if pkesk if pkesk
.decrypt(&mut keypair, sym_algo) .decrypt(&mut keypair, sym_algo)
@ -155,6 +165,6 @@ impl DecryptionHelper for &mut Keyring {
} }
} }
Err(KeyringError::SecretKeyNotFound.into()) Err(Error::SecretKeyNotFound.into())
} }
} }

View File

@ -11,11 +11,12 @@ use super::openpgp::{
}; };
use crate::prompt_manager::{PinentryError, PromptManager}; use crate::prompt_manager::{PinentryError, PromptManager};
use anyhow::Context;
use card_backend_pcsc::PcscBackend; use card_backend_pcsc::PcscBackend;
use openpgp_card_sequoia::{state::Open, Card}; use openpgp_card_sequoia::{state::Open, types::Error as SequoiaCardError, Card};
#[derive(thiserror::Error, Debug)] #[derive(thiserror::Error, Debug)]
pub enum SmartcardError { pub enum Error {
#[error("No smart card backend was stored")] #[error("No smart card backend was stored")]
SmartCardNotFound, SmartCardNotFound,
@ -23,16 +24,28 @@ pub enum SmartcardError {
SmartCardHasNoDecrypt, SmartCardHasNoDecrypt,
#[error("Smart card backend error: {0}")] #[error("Smart card backend error: {0}")]
SmartCardBackendError(#[from] card_backend::SmartcardError), SmartCardBackend(#[from] card_backend::SmartcardError),
#[error("Smart card error: {0}")] #[error("Smartcard password status unavailable: {0}")]
SmartCardEncounteredError(#[from] openpgp_card_sequoia::types::Error), PwStatusBytes(SequoiaCardError),
#[error("Could not open smart card")]
OpenSmartCard(SequoiaCardError),
#[error("Could not initialize transaction")]
Transaction(SequoiaCardError),
#[error("Could not load fingerprints")]
Fingerprints(SequoiaCardError),
#[error("Invalid PIN entered too many times")]
InvalidPIN,
#[error("Prompt failed: {0}")] #[error("Prompt failed: {0}")]
Prompt(#[from] PinentryError), Prompt(#[from] PinentryError),
} }
pub type Result<T, E = SmartcardError> = std::result::Result<T, E>; pub type Result<T, E = Error> = std::result::Result<T, E>;
fn format_name(input: impl AsRef<str>) -> String { fn format_name(input: impl AsRef<str>) -> String {
let mut n = input let mut n = input
@ -72,21 +85,20 @@ impl SmartcardManager {
PcscBackend::cards(None)? PcscBackend::cards(None)?
.next() .next()
.transpose()? .transpose()?
.ok_or(SmartcardError::SmartCardNotFound) .ok_or(Error::SmartCardNotFound)
.and_then( .and_then(|backend| {
|backend| { let mut card = Card::<Open>::new(backend).map_err(Error::OpenSmartCard)?;
let mut card = Card::<Open>::new(backend)?; let transaction = card.transaction().map_err(Error::Transaction)?;
let transaction = card.transaction()?; let fingerprint = transaction
let fingerprint = transaction .fingerprints()
.fingerprints()? .map_err(Error::Fingerprints)?
.decryption() .decryption()
.map(|fp| Fingerprint::from_bytes(fp.as_bytes())) .map(|fp| Fingerprint::from_bytes(fp.as_bytes()))
.ok_or(SmartcardError::SmartCardHasNoDecrypt)?; .ok_or(Error::SmartCardHasNoDecrypt)?;
drop(transaction); drop(transaction);
self.current_card.replace(card); self.current_card.replace(card);
Ok(fingerprint) Ok(fingerprint)
}, })
)
} }
/// Load a backend if any [`Fingerprint`] has been matched by a currently active card. /// Load a backend if any [`Fingerprint`] has been matched by a currently active card.
@ -108,11 +120,12 @@ impl SmartcardManager {
for backend in PcscBackend::cards(None)? { for backend in PcscBackend::cards(None)? {
had_any_backend = true; had_any_backend = true;
let backend = backend?; let backend = backend?;
let mut card = Card::<Open>::new(backend)?; let mut card = Card::<Open>::new(backend).map_err(Error::OpenSmartCard)?;
let transaction = card.transaction()?; let transaction = card.transaction().map_err(Error::Transaction)?;
let mut fingerprint = None; let mut fingerprint = None;
if let Some(fp) = transaction if let Some(fp) = transaction
.fingerprints()? .fingerprints()
.map_err(Error::Fingerprints)?
.decryption() .decryption()
.map(|fp| Fingerprint::from_bytes(fp.as_bytes())) .map(|fp| Fingerprint::from_bytes(fp.as_bytes()))
{ {
@ -127,9 +140,8 @@ impl SmartcardManager {
} }
} }
eprintln!("No matching smartcard detected."); #[rustfmt::skip]
self.pm self.pm.prompt_message("Please plug in a smart card and press enter")?;
.prompt_message("Please plug in a smart card and press enter")?;
} }
Ok(None) Ok(None)
@ -158,7 +170,7 @@ impl VerificationHelper for &mut SmartcardManager {
for result in results { for result in results {
if let Err(e) = result { if let Err(e) = result {
// FIXME: anyhow leak // FIXME: anyhow leak
return Err(anyhow::anyhow!(e.to_string())); return Err(anyhow::anyhow!("Verification error: {}", e.to_string()));
} }
} }
} }
@ -181,28 +193,59 @@ impl DecryptionHelper for &mut SmartcardManager {
{ {
let mut card = self.current_card.take(); let mut card = self.current_card.take();
let Some(card) = card.as_mut() else { let Some(card) = card.as_mut() else {
return Err(SmartcardError::SmartCardNotFound.into()); return Err(Error::SmartCardNotFound.into());
}; };
let mut transaction = card.transaction()?; let mut transaction = card
.transaction()
.context("Could not initialize transaction")?;
let fp = transaction let fp = transaction
.fingerprints()? .fingerprints()
.context("Could not load fingerprints")?
.decryption() .decryption()
.map(|fp| Fingerprint::from_bytes(fp.as_bytes())); .map(|fp| Fingerprint::from_bytes(fp.as_bytes()))
let Some(fp) = fp else { .ok_or(Error::SmartCardHasNoDecrypt)?;
return Err(SmartcardError::SmartCardHasNoDecrypt.into()); let cardholder_name = format_name(
}; transaction
let cardholder_name = format_name(transaction.cardholder_name()?); .cardholder_name()
let card_id = transaction.application_identifier()?.ident(); .context("Could not load (optionally empty) cardholder name")?,
let message = if cardholder_name.is_empty() { );
format!("Unlock card {card_id}") let card_id = transaction
} else { .application_identifier()
format!("Unlock card {card_id} ({cardholder_name})") .context("Could not load application identifier")?
}; .ident();
let pin = self.pm.prompt_passphrase("Smartcard User PIN", message)?; let pw_status = transaction
let mut user = transaction.to_user_card(pin.expose_secret().as_str().trim())?; .pw_status_bytes()
let mut decryptor = .map_err(Error::PwStatusBytes)?;
user.decryptor(&|| eprintln!("Touch confirmation needed for decryption"))?; let mut pin = None;
for _ in 0..pw_status.err_count_pw1() {
transaction.reload_ard()?;
let attempts = transaction
.pw_status_bytes()
.map_err(Error::PwStatusBytes)?
.err_count_pw1();
let rpea = "Remaining PIN entry attempts";
let message = if cardholder_name.is_empty() {
format!("Unlock card {card_id}\n\n{rpea}: {attempts}")
} else {
format!("Unlock card {card_id} ({cardholder_name})\n\n{rpea}: {attempts}")
};
let temp_pin = self.pm.prompt_passphrase("Smartcard User PIN", message)?;
if transaction
.verify_user_pin(temp_pin.expose_secret().as_str().trim())
.is_ok()
{
pin.replace(temp_pin);
break;
}
}
let pin = pin.ok_or(Error::InvalidPIN)?;
let mut user = transaction
.to_user_card(pin.expose_secret().as_str().trim())
.context("Could not load user smartcard from PIN")?;
let mut decryptor = user
.decryptor(&|| eprintln!("Touch confirmation needed for decryption"))
.context("Could not decrypt using smartcard")?;
for pkesk in pkesks { for pkesk in pkesks {
if pkesk if pkesk
.decrypt(&mut decryptor, sym_algo) .decrypt(&mut decryptor, sym_algo)
@ -213,6 +256,6 @@ impl DecryptionHelper for &mut SmartcardManager {
} }
} }
Err(SmartcardError::SmartCardNotFound.into()) Err(Error::SmartCardNotFound.into())
} }
} }