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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
use crate::authenticatorservice::{RegisterArgs, SignArgs};
use crate::ctap2;
use crate::ctap2::commands::client_pin::Pin;
use crate::errors::AuthenticatorError;
use crate::statecallback::StateCallback;
use crate::status_update::{send_status, InteractiveUpdate};
use crate::transport::device_selector::{
BlinkResult, Device, DeviceBuildParameters, DeviceCommand, DeviceSelectorEvent,
};
use crate::transport::platform::transaction::Transaction;
use crate::transport::{hid::HIDDevice, FidoDevice, FidoProtocol};
use crate::{InteractiveRequest, ManageResult};
use std::sync::mpsc::{channel, RecvTimeoutError, Sender};
use std::time::Duration;
#[derive(Default)]
pub struct StateMachine {
transaction: Option<Transaction>,
}
impl StateMachine {
pub fn new() -> Self {
Default::default()
}
fn init_device(
info: DeviceBuildParameters,
selector: &Sender<DeviceSelectorEvent>,
) -> Option<Device> {
// Create a new device.
let mut dev = match Device::new(info) {
Ok(dev) => dev,
Err((e, id)) => {
info!("error happened with device: {}", e);
let _ = selector.send(DeviceSelectorEvent::NotAToken(id));
return None;
}
};
// Try initializing it.
if let Err(e) = dev.init() {
warn!("error while initializing device: {}", e);
let _ = selector.send(DeviceSelectorEvent::NotAToken(dev.id()));
return None;
}
Some(dev)
}
fn wait_for_device_selector(
dev: &mut Device,
selector: &Sender<DeviceSelectorEvent>,
status: &Sender<crate::StatusUpdate>,
keep_alive: &dyn Fn() -> bool,
) -> bool {
let (tx, rx) = channel();
if selector
.send(DeviceSelectorEvent::ImAToken((dev.id(), tx)))
.is_err()
{
// If we fail to register with the device selector, then we're not going
// to be selected.
return false;
}
// We can be cancelled from the user (through keep_alive()) or from the device selector
// (through a DeviceCommand::Cancel on rx). We'll combine those signals into a single
// predicate to pass to Device::block_and_blink.
let keep_blinking = || keep_alive() && !matches!(rx.try_recv(), Ok(DeviceCommand::Cancel));
// Blocking recv. DeviceSelector will tell us what to do
match rx.recv() {
Ok(DeviceCommand::Blink) => {
// The caller wants the user to choose a device. Send a status update and blink
// this device. NOTE: We send one status update per device, so the recipient should be
// prepared to receive the message multiple times.
send_status(status, crate::StatusUpdate::SelectDeviceNotice);
match dev.block_and_blink(&keep_blinking) {
BlinkResult::DeviceSelected => {
// User selected us. Let DeviceSelector know, so it can cancel all other
// outstanding open blink-requests. If we fail to send the SelectedToken
// message to the device selector, then don't consider this token as having
// been selected.
selector
.send(DeviceSelectorEvent::SelectedToken(dev.id()))
.is_ok()
}
BlinkResult::Cancelled => {
info!("Device {:?} was not selected", dev.id());
false
}
}
}
Ok(DeviceCommand::Cancel) => {
info!("Device {:?} was not selected", dev.id());
false
}
Ok(DeviceCommand::Removed) => {
info!("Device {:?} was removed", dev.id());
false
}
Ok(DeviceCommand::Continue) => true,
Err(_) => {
warn!("Error when trying to receive messages from DeviceSelector! Exiting.");
false
}
}
}
pub fn register(
&mut self,
timeout: u64,
args: RegisterArgs,
status: Sender<crate::StatusUpdate>,
callback: StateCallback<crate::Result<crate::RegisterResult>>,
) {
// Abort any prior register/sign calls.
self.cancel();
let cbc = callback.clone();
let transaction = Transaction::new(
timeout,
cbc.clone(),
status,
move |info, selector, status, alive| {
let mut dev = match Self::init_device(info, &selector) {
Some(dev) => dev,
None => return,
};
if !Self::wait_for_device_selector(&mut dev, &selector, &status, alive) {
return;
};
if args.use_ctap1_fallback {
dev.downgrade_to_ctap1();
}
info!("Device {:?} continues with the register process", dev.id());
if ctap2::register(&mut dev, args.clone(), status, callback.clone(), alive) {
// ctap2::register returns true if it called the callback with Ok(..). Cancel
// all other tokens in case we skipped the "blinking"-action and went straight
// for the actual request.
let _ = selector.send(DeviceSelectorEvent::SelectedToken(dev.id()));
}
},
);
self.transaction = Some(try_or!(transaction, |e| cbc.call(Err(e))));
}
pub fn sign(
&mut self,
timeout: u64,
args: SignArgs,
status: Sender<crate::StatusUpdate>,
callback: StateCallback<crate::Result<crate::SignResult>>,
) {
// Abort any prior register/sign calls.
self.cancel();
let cbc = callback.clone();
let transaction = Transaction::new(
timeout,
callback.clone(),
status,
move |info, selector, status, alive| {
let mut dev = match Self::init_device(info, &selector) {
Some(dev) => dev,
None => return,
};
if !Self::wait_for_device_selector(&mut dev, &selector, &status, alive) {
return;
};
if args.use_ctap1_fallback {
dev.downgrade_to_ctap1();
}
info!("Device {:?} continues with the signing process", dev.id());
if ctap2::sign(&mut dev, args.clone(), status, callback.clone(), alive) {
// ctap2::sign returns true if it called the callback with Ok(..). Cancel all
// other tokens in case we skipped the "blinking"-action and went straight for
// the actual request.
let _ = selector.send(DeviceSelectorEvent::SelectedToken(dev.id()));
}
},
);
self.transaction = Some(try_or!(transaction, move |e| cbc.call(Err(e))));
}
// This blocks.
pub fn cancel(&mut self) {
if let Some(mut transaction) = self.transaction.take() {
info!("Statemachine was cancelled. Cancelling transaction now.");
transaction.cancel();
}
}
pub fn reset(
&mut self,
timeout: u64,
status: Sender<crate::StatusUpdate>,
callback: StateCallback<crate::Result<crate::ResetResult>>,
) {
// Abort any prior register/sign calls.
self.cancel();
let cbc = callback.clone();
let transaction = Transaction::new(
timeout,
callback.clone(),
status,
move |info, selector, status, alive| {
let mut dev = match Self::init_device(info, &selector) {
Some(dev) => dev,
None => return,
};
if dev.get_protocol() != FidoProtocol::CTAP2 {
info!("Device does not support CTAP2");
let _ = selector.send(DeviceSelectorEvent::NotAToken(dev.id()));
return;
}
if !Self::wait_for_device_selector(&mut dev, &selector, &status, alive) {
return;
};
ctap2::reset_helper(&mut dev, selector, status, callback.clone(), alive);
},
);
self.transaction = Some(try_or!(transaction, move |e| cbc.call(Err(e))));
}
pub fn set_pin(
&mut self,
timeout: u64,
new_pin: Pin,
status: Sender<crate::StatusUpdate>,
callback: StateCallback<crate::Result<crate::ResetResult>>,
) {
// Abort any prior register/sign calls.
self.cancel();
let cbc = callback.clone();
let transaction = Transaction::new(
timeout,
callback.clone(),
status,
move |info, selector, status, alive| {
let mut dev = match Self::init_device(info, &selector) {
Some(dev) => dev,
None => return,
};
if dev.get_protocol() != FidoProtocol::CTAP2 {
info!("Device does not support CTAP2");
let _ = selector.send(DeviceSelectorEvent::NotAToken(dev.id()));
return;
}
if !Self::wait_for_device_selector(&mut dev, &selector, &status, alive) {
return;
};
ctap2::set_or_change_pin_helper(
&mut dev,
None,
new_pin.clone(),
status,
callback.clone(),
alive,
);
},
);
self.transaction = Some(try_or!(transaction, move |e| cbc.call(Err(e))));
}
// Function to interactively manage a specific token.
// Difference to register/sign: These want to do something and don't care
// with which token they do it.
// This function wants to manipulate a specific token. For this, we first
// have to select one and then do something with it, based on what it
// supports (Set PIN, Change PIN, Reset, etc.).
// Hence, we first go through the discovery-phase, then provide the user
// with the AuthenticatorInfo and then let them interactively decide what to do
pub fn manage(
&mut self,
timeout: u64,
status: Sender<crate::StatusUpdate>,
callback: StateCallback<crate::Result<crate::ManageResult>>,
) {
// Abort any prior register/sign calls.
self.cancel();
let cbc = callback.clone();
let transaction = Transaction::new(
timeout,
callback.clone(),
status,
move |info, selector, status, alive| {
let mut dev = match Self::init_device(info, &selector) {
Some(dev) => dev,
None => return,
};
if dev.get_protocol() != FidoProtocol::CTAP2 {
info!("Device does not support CTAP2");
let _ = selector.send(DeviceSelectorEvent::NotAToken(dev.id()));
return;
}
if !Self::wait_for_device_selector(&mut dev, &selector, &status, alive) {
return;
};
info!("Device {:?} selected for interactive management.", dev.id());
// Sending the user the info about the token
let (tx, rx) = channel();
send_status(
&status,
crate::StatusUpdate::InteractiveManagement(InteractiveUpdate::StartManagement(
(tx, dev.get_authenticator_info().cloned()),
)),
);
while alive() {
match rx.recv_timeout(Duration::from_millis(400)) {
Ok(InteractiveRequest::Quit) => {
callback.call(Ok(ManageResult::Success));
break;
}
Ok(InteractiveRequest::Reset) => {
ctap2::reset_helper(
&mut dev,
selector,
status,
callback.clone(),
alive,
);
}
Ok(InteractiveRequest::ChangePIN(curr_pin, new_pin)) => {
ctap2::set_or_change_pin_helper(
&mut dev,
Some(curr_pin),
new_pin,
status,
callback.clone(),
alive,
);
}
Ok(InteractiveRequest::SetPIN(pin)) => {
ctap2::set_or_change_pin_helper(
&mut dev,
None,
pin,
status,
callback.clone(),
alive,
);
}
Ok(InteractiveRequest::ChangeConfig(authcfg, puat)) => {
ctap2::configure_authenticator(
&mut dev,
puat,
authcfg,
status.clone(),
callback.clone(),
alive,
);
continue;
}
Ok(InteractiveRequest::CredentialManagement(cred_management, puat)) => {
ctap2::credential_management(
&mut dev,
puat,
cred_management,
status.clone(),
callback.clone(),
alive,
);
continue;
}
Ok(InteractiveRequest::BioEnrollment(bio_enrollment, puat)) => {
ctap2::bio_enrollment(
&mut dev,
puat,
bio_enrollment,
status.clone(),
callback.clone(),
alive,
);
continue;
}
Err(RecvTimeoutError::Timeout) => {
if !alive() {
// We got stopped at some point
callback.call(Err(AuthenticatorError::CancelledByUser));
break;
}
continue;
}
Err(RecvTimeoutError::Disconnected) => {
// recv() failed, because the other side is dropping the Sender.
info!(
"Callback dropped the channel, so we abort the interactive session"
);
callback.call(Err(AuthenticatorError::CancelledByUser));
}
}
break;
}
},
);
self.transaction = Some(try_or!(transaction, move |e| cbc.call(Err(e))));
}
}