Files
proton-stream/crates/pstr-core/src/account.rs
T
nvrl 4a3a7291b8 chore(deps): proton-sdk and proton-drive-rs 0.9.0
Adapt sign-in to the 0.8 account API and use what it adds:

- Key passphrases are KeyPassphrases now, wiped on drop. The stored
  session keeps its JSON shape and converts on unlock.
- The mailbox password is checked with AccountClient::unlock(), one
  core/v4/users request instead of loading every address, and a wrong
  one is recognised as ProtonError::KeysLocked instead of any
  InvalidOperation.
- KeysLocked from a resumed session counts as signed out: the mailbox
  password changed, and only signing in again derives passphrases that
  unlock the keys.
- A sign-in Proton answers with code 2028 (Blocked) says so, instead of
  showing the server text that claims the app version is outdated.

Also picked up without code changes: a token refresh that outlives its
caller and is never replayed (0.8.2).
2026-10-15 19:56:56 +02:00

706 lines
25 KiB
Rust

//! Signing in to a Proton account, and keeping the session.
//!
//! The rest of the app works without one — public links need no account. A
//! signed-in account adds two things: folders of the viewer's own Drive (My
//! Files, other devices, what was shared with them) as library shares, and
//! watch history kept in their Drive so every device resumes where another
//! left off ([`crate::sync`]).
//!
//! ## What is kept, and where
//!
//! One JSON blob in the [`SecretStore`] holding the session tokens and, per
//! account key, the passphrase that unlocks it. Those passphrases are derived
//! at sign-in from the mailbox password and the key salts, and kept *instead*
//! of the password: they unlock the key chain just the same, but a store that
//! leaks gives away this app's access to the account rather than the password
//! — which, on a single-password account, is the login password itself.
//! Deriving them later is not an option either way: `core/v4/keys/salts`
//! needs a scope only a password sign-in grants, and answers 403 after the
//! first token refresh.
//!
//! Proton refresh tokens are single-use, so every refresh is written back
//! (see [`persist_refreshed_tokens`]). A refresh that is not leaves the store
//! holding a dead token and the next launch signed out.
//!
//! ## Signing in is several steps
//!
//! Password, then maybe a second-factor code, then — on an account with a
//! separate mailbox password — that. Each front end asks for them in its own
//! way, so [`AccountStore::sign_in`] returns a [`SignIn`] saying what it needs
//! next and holding the half-made session until it is given.
use std::collections::HashMap;
use std::sync::Arc;
use proton_drive_rs::{NodeKind, ProtonDriveClient};
use proton_sdk::account::KeyPassphrases;
use proton_sdk::api::{HumanVerificationCredential, ResponseCode};
use proton_sdk::error::ProtonError;
use proton_sdk::ids::NodeUid;
use proton_sdk::session::{PasswordMode, ProtonApiSession, ResumeParameters};
use serde::{Deserialize, Serialize};
use crate::error::{Error, Result};
use crate::shares::{SecretStore, client_configuration};
/// The secret-store key the session is kept under. Share secrets are keyed
/// `share-…`, so the two cannot collide.
const SESSION_KEY: &str = "proton-account";
/// Why an account whose only second factor is a security key cannot sign in.
const SECURITY_KEY_ONLY: &str = "This account's only second factor is a security key, which this \
app cannot use yet. Add an authenticator app in your Proton account settings, then sign in \
with its code.";
/// Why a sign-in Proton answered with [`ResponseCode::Blocked`] failed. The
/// server's own text says the app version is no longer supported, which is
/// not true and sends the viewer looking for an update that does not exist.
const SIGN_IN_BLOCKED: &str = "Proton has blocked sign-ins from this app for now. Wait a while \
and try again, or sign in once on proton.me first.";
/// Blocks in flight for streaming from the account, as for a public link —
/// see `ShareStore::open`.
const MAX_INFLIGHT_BLOCKS: usize = 48;
/// Everything needed to resume the session unattended.
#[derive(Serialize, Deserialize, Clone)]
struct StoredSession {
session_id: String,
username: String,
user_id: String,
access_token: String,
refresh_token: String,
scopes: Vec<String>,
/// `1` single password, `2` separate mailbox password — Proton's values.
password_mode: u8,
/// Key id → the passphrase that unlocks it. ASCII: they are bcrypt output.
key_passphrases: HashMap<String, String>,
}
impl StoredSession {
fn capture(
session: &ProtonApiSession,
tokens: proton_sdk::http::Tokens,
key_passphrases: HashMap<String, String>,
) -> Self {
Self {
session_id: session.session_id().as_str().to_owned(),
username: session.username().to_owned(),
user_id: session.user_id().as_str().to_owned(),
access_token: tokens.access_token,
refresh_token: tokens.refresh_token,
scopes: session.scopes().to_vec(),
password_mode: match session.password_mode() {
PasswordMode::Single => 1,
PasswordMode::Dual => 2,
},
key_passphrases,
}
}
fn unlock(&self) -> KeyPassphrases {
self.key_passphrases
.iter()
.map(|(id, passphrase)| (id.as_str(), passphrase.as_bytes()))
.collect()
}
fn resume_parameters(&self) -> ResumeParameters {
ResumeParameters {
session_id: self.session_id.clone().into(),
username: self.username.clone(),
user_id: self.user_id.clone().into(),
access_token: self.access_token.clone(),
refresh_token: self.refresh_token.clone(),
scopes: self.scopes.clone(),
is_waiting_for_second_factor_code: false,
password_mode: match self.password_mode {
1 => PasswordMode::Single,
_ => PasswordMode::Dual,
},
}
}
}
/// A signed-in account, ready for Drive work.
///
/// Cheap to clone; clones share one session and one set of caches.
#[derive(Clone)]
pub struct Account {
session: ProtonApiSession,
drive: ProtonDriveClient,
}
impl Account {
/// The address the viewer signed in with.
pub fn username(&self) -> &str {
self.session.username()
}
/// The Drive client the account's folders and watch history go through.
pub fn drive(&self) -> &ProtonDriveClient {
&self.drive
}
/// Where a library folder can come from: My Files, each device, and each
/// folder someone shared with the viewer.
///
/// The device this app keeps watch history in is left out — it holds
/// nothing to watch. A device or share whose name will not decrypt is
/// still listed, under a placeholder, rather than hidden: it is the
/// viewer's, and they can still open it.
pub async fn places(&self) -> Result<Vec<DrivePlace>> {
let mut places = Vec::new();
let my_files = self.drive.get_my_files_folder().await?;
places.push(DrivePlace {
kind: PlaceKind::MyFiles,
name: "My files".to_owned(),
uid: my_files.uid,
});
let mut devices = self.drive.enumerate_devices().await?;
devices.sort_by_key(|device| device.creation_time);
for device in devices {
let name = device.name.unwrap_or_else(|_| "Unnamed device".to_owned());
if name == crate::sync::DEVICE_NAME {
continue;
}
places.push(DrivePlace {
kind: PlaceKind::Device,
name,
uid: device.root_folder_uid,
});
}
let shared: Vec<NodeUid> = self
.drive
.enumerate_shared_with_me()
.await?
.into_iter()
.map(|item| item.uid)
.collect();
if !shared.is_empty() {
let mut nodes = self.drive.enumerate_nodes(&shared).await?;
nodes.retain(|node| node.is_folder() && !node.trashed);
nodes.sort_by_key(|node| node.name.to_lowercase());
places.extend(nodes.into_iter().map(|node| DrivePlace {
kind: PlaceKind::SharedWithMe,
name: node.name,
uid: node.uid,
}));
}
Ok(places)
}
/// What one folder of the account holds: folders first, then files, each
/// by name. Trashed nodes are left out.
pub async fn folder_children(&self, folder: &NodeUid) -> Result<Vec<DriveEntry>> {
let uids = self
.drive
.enumerate_folder_children_node_uids(folder)
.await?;
if uids.is_empty() {
return Ok(Vec::new());
}
let mut entries: Vec<DriveEntry> = self
.drive
.enumerate_nodes(&uids)
.await?
.into_iter()
.filter(|node| !node.trashed)
.map(|node| {
let (size, media_type) = match &node.kind {
NodeKind::File {
media_type,
claimed_size,
..
} => (*claimed_size, Some(media_type.clone())),
_ => (None, None),
};
DriveEntry {
is_folder: node.is_folder(),
uid: node.uid,
name: node.name,
size,
media_type,
}
})
.collect();
entries.sort_by(|a, b| {
b.is_folder
.cmp(&a.is_folder)
.then_with(|| a.name.to_lowercase().cmp(&b.name.to_lowercase()))
});
Ok(entries)
}
/// End the session on Proton's side. Best-effort: a session that is
/// already dead has nothing to end.
async fn end(&self) {
if let Err(error) = self.session.end().await {
tracing::debug!(%error, "ending the Proton session failed");
}
}
}
/// Which kind of place a [`DrivePlace`] is.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum PlaceKind {
MyFiles,
Device,
SharedWithMe,
}
/// A top-level place in the account's Drive.
#[derive(Debug, Clone)]
pub struct DrivePlace {
pub kind: PlaceKind,
pub name: String,
pub uid: NodeUid,
}
/// One node of a folder listing.
#[derive(Debug, Clone)]
pub struct DriveEntry {
pub uid: NodeUid,
pub name: String,
pub is_folder: bool,
/// Plaintext size, when the uploader recorded one.
pub size: Option<i64>,
pub media_type: Option<String>,
}
/// Where a sign-in stands.
pub enum SignIn {
/// Signed in; the session is stored.
Done(Account),
/// The account has two-factor authentication: ask for a code and pass it to
/// [`PendingSignIn::second_factor`].
SecondFactor(PendingSignIn),
/// The account has a separate mailbox password: ask for it and pass it to
/// [`PendingSignIn::mailbox_password`].
MailboxPassword(PendingSignIn),
}
/// A sign-in waiting on the viewer.
pub struct PendingSignIn {
secrets: Arc<dyn SecretStore>,
session: ProtonApiSession,
password: String,
}
impl PendingSignIn {
/// Submit a second-factor code.
///
/// A wrong code fails here and leaves nothing behind; the front end starts
/// the sign-in over, because Proton does not accept a second try on the
/// same half-made session.
pub async fn second_factor(mut self, code: &str) -> Result<SignIn> {
self.session
.apply_second_factor_code(code.trim())
.await
.map_err(|error| match error {
ProtonError::Api(api) if (400..500).contains(&api.http_status) => {
Error::SignIn("that code was not accepted".to_owned())
}
other => other.into(),
})?;
self.after_second_factor().await
}
/// Submit the mailbox password, on an account that has one.
///
/// By reference, unlike the code: a mistyped mailbox password is checked
/// on this side, the session survives it, and the viewer can try again
/// without starting over.
pub async fn mailbox_password(&self, mailbox_password: &str) -> Result<Account> {
finish(
Arc::clone(&self.secrets),
self.session.clone(),
mailbox_password,
)
.await
}
async fn after_second_factor(self) -> Result<SignIn> {
if self.session.password_mode() == PasswordMode::Dual {
return Ok(SignIn::MailboxPassword(self));
}
let password = self.password.clone();
finish(self.secrets, self.session, &password)
.await
.map(SignIn::Done)
}
}
/// The signed-in account, if any, and signing in and out.
#[derive(Clone)]
pub struct AccountStore {
secrets: Arc<dyn SecretStore>,
}
impl AccountStore {
pub fn new(secrets: Arc<dyn SecretStore>) -> Self {
Self { secrets }
}
/// The address of the stored account, without touching the network.
pub fn username(&self) -> Result<Option<String>> {
Ok(self.load()?.map(|stored| stored.username))
}
/// Start signing in.
///
/// `verification` is the token from a solved CAPTCHA, after a first try
/// failed with [`Error::HumanVerification`]; the sign-in starts over with
/// it, because the gated attempt's SRP handshake is spent.
pub async fn sign_in(
&self,
username: &str,
password: &str,
verification: Option<HumanVerificationCredential>,
) -> Result<SignIn> {
let session = ProtonApiSession::begin_verified(
client_configuration(),
username.trim(),
password.as_bytes(),
verification.as_ref(),
)
.await
.map_err(classify_sign_in_failure)?;
let pending = PendingSignIn {
secrets: Arc::clone(&self.secrets),
session,
password: password.to_owned(),
};
if pending.session.is_waiting_for_second_factor() {
let methods = pending.session.second_factor_methods();
if methods.fido2 && !methods.totp {
// A security key needs WebAuthn, which this sign-in does not
// speak; asking for a code would only fail as a wrong one.
pending.session.end().await.ok();
return Err(Error::SignIn(SECURITY_KEY_ONLY.to_owned()));
}
return Ok(SignIn::SecondFactor(pending));
}
pending.after_second_factor().await
}
/// The stored account, resumed, or `None` when nobody is signed in.
///
/// Makes no request: a session whose refresh token has died is found out
/// by the first call that uses it, as [`Error::is_signed_out`].
pub fn resume(&self) -> Result<Option<Account>> {
let Some(stored) = self.load()? else {
return Ok(None);
};
let session = ProtonApiSession::resume(client_configuration(), stored.resume_parameters())?;
persist_refreshed_tokens(&self.secrets, &session, stored.key_passphrases.clone());
let drive = ProtonDriveClient::with_key_passphrases(&session, stored.unlock());
Ok(Some(account(session, drive)))
}
/// Forget the account: end its session and delete what was stored.
///
/// The stored session goes even when ending it fails — signing out on a
/// plane must still sign out.
pub async fn sign_out(&self, account: Option<&Account>) -> Result<()> {
if let Some(account) = account {
account.end().await;
}
self.secrets.delete(SESSION_KEY)
}
/// The stored session, or `None` for none — or for one this build cannot
/// read, such as the shape development builds before 1.2.0 stored, which
/// kept the mailbox password. Signing in again is the only fix for either,
/// and it replaces what is there.
fn load(&self) -> Result<Option<StoredSession>> {
let Some(encoded) = self.secrets.get(SESSION_KEY)? else {
return Ok(None);
};
Ok(serde_json::from_str(&encoded)
.inspect_err(|error| {
tracing::warn!(%error, "the stored Proton session is unreadable; sign in again");
})
.ok())
}
}
/// Unlock the key chain with `mailbox_password`, store the session, and hand
/// back the account.
///
/// The key passphrases are derived here, while the token still has the scope
/// the key salts need. Unlocking the user keys is what proves the mailbox
/// password: a wrong one unlocks none of them. Only the passphrases are
/// stored; the password goes no further.
async fn finish(
secrets: Arc<dyn SecretStore>,
session: ProtonApiSession,
mailbox_password: &str,
) -> Result<Account> {
let probe = ProtonDriveClient::new(&session, mailbox_password.as_bytes().to_vec());
probe
.account()
.unlock()
.await
.map_err(|error| match error {
ProtonError::KeysLocked => {
Error::SignIn("that mailbox password did not unlock the account".to_owned())
}
other => other.into(),
})?;
let key_passphrases = probe
.account()
.key_passphrases()
.await?
.iter()
.map(|(id, passphrase)| {
std::str::from_utf8(passphrase)
.map(|passphrase| (id.to_owned(), passphrase.to_owned()))
.map_err(|_| Error::Config("a derived key passphrase is not text".to_owned()))
})
.collect::<Result<HashMap<_, _>>>()?;
let stored = StoredSession::capture(
&session,
session.current_tokens().await,
key_passphrases.clone(),
);
let encoded = serde_json::to_string(&stored)
.map_err(|e| Error::Config(format!("serialize the Proton session: {e}")))?;
secrets.set(SESSION_KEY, &encoded)?;
persist_refreshed_tokens(&secrets, &session, key_passphrases);
let drive = ProtonDriveClient::with_key_passphrases(&session, stored.unlock());
Ok(account(session, drive))
}
fn account(session: ProtonApiSession, drive: ProtonDriveClient) -> Account {
let drive = drive
.with_max_inflight_blocks(MAX_INFLIGHT_BLOCKS)
// A watch-history file is one small block; the single-request upload
// is one failure point where the draft dance is three.
.with_small_file_upload(true);
Account { session, drive }
}
/// Write every refreshed token pair back to the secret store.
///
/// Refresh tokens are single-use: once the HTTP client has spent the stored
/// one, only the pair it got back can resume the session.
fn persist_refreshed_tokens(
secrets: &Arc<dyn SecretStore>,
session: &ProtonApiSession,
key_passphrases: HashMap<String, String>,
) {
let secrets = Arc::clone(secrets);
let template = session.clone();
session.http().set_on_tokens_refreshed(move |tokens| {
let stored = StoredSession::capture(&template, tokens, key_passphrases.clone());
let written = serde_json::to_string(&stored)
.map_err(|e| Error::Config(e.to_string()))
.and_then(|encoded| secrets.set(SESSION_KEY, &encoded));
if let Err(error) = written {
tracing::warn!(%error, "the refreshed Proton session could not be stored");
}
});
}
/// Lift a CAPTCHA gate, a blocked sign-in and a wrong password out of the
/// generic API error.
///
/// Only a gate that can be solved in an app becomes
/// [`Error::HumanVerification`]; one that wants an e-mail or SMS code is a plain
/// failure, which reads better than an empty verification page.
fn classify_sign_in_failure(error: ProtonError) -> Error {
if let ProtonError::Api(api) = &error {
if let Some(challenge) = api.human_verification()
&& challenge.supports_captcha()
{
return Error::HumanVerification(Box::new(challenge));
}
if api.code == ResponseCode::Blocked {
return Error::SignIn(SIGN_IN_BLOCKED.to_owned());
}
if api.http_status == 422 && !api.is_human_verification_required() {
return Error::SignIn(if api.message.is_empty() {
"Proton did not accept that address and password".to_owned()
} else {
api.message.clone()
});
}
}
error.into()
}
/// The token out of a message posted by Proton's verification page, or `None`
/// for anything that is not a completion.
///
/// The page posts plenty besides — resize requests, readiness pings — and
/// taking an unrecognised message for success would retry the sign-in with a
/// garbage token. Both spellings of the success type have shipped, and some
/// hosts hand the message over stringified twice.
pub fn verification_token(raw: &str) -> Option<String> {
let mut value: serde_json::Value = serde_json::from_str(raw).ok()?;
if let Some(inner) = value.as_str()
&& let Ok(parsed) = serde_json::from_str(inner)
{
value = parsed;
}
let kind = value.get("type")?.as_str()?;
if !matches!(
kind,
"HUMAN_VERIFICATION_SUCCESS" | "human_verification_success"
) {
return None;
}
let token = value.get("payload")?.get("token")?.as_str()?;
(!token.is_empty()).then(|| token.to_owned())
}
#[cfg(test)]
mod tests {
use std::collections::HashMap;
use parking_lot::Mutex;
use super::*;
#[derive(Default)]
struct MemorySecrets(Mutex<HashMap<String, String>>);
impl SecretStore for MemorySecrets {
fn set(&self, key: &str, value: &str) -> Result<()> {
self.0.lock().insert(key.to_owned(), value.to_owned());
Ok(())
}
fn get(&self, key: &str) -> Result<Option<String>> {
Ok(self.0.lock().get(key).cloned())
}
fn delete(&self, key: &str) -> Result<()> {
self.0.lock().remove(key);
Ok(())
}
}
fn stored() -> StoredSession {
StoredSession {
session_id: "session".to_owned(),
username: "viewer@proton.me".to_owned(),
user_id: "user".to_owned(),
access_token: "access".to_owned(),
refresh_token: "refresh".to_owned(),
scopes: vec!["drive".to_owned()],
password_mode: 2,
key_passphrases: HashMap::from([("key-1".to_owned(), "derived".to_owned())]),
}
}
#[test]
fn nobody_is_signed_in_until_a_session_is_stored() {
let store = AccountStore::new(Arc::new(MemorySecrets::default()));
assert_eq!(store.username().expect("read"), None);
assert!(store.resume().expect("resume").is_none());
}
#[test]
fn a_stored_session_resumes_as_its_account_without_a_request() {
let secrets = Arc::new(MemorySecrets::default());
secrets
.set(SESSION_KEY, &serde_json::to_string(&stored()).unwrap())
.unwrap();
let store = AccountStore::new(secrets);
assert_eq!(
store.username().expect("read").as_deref(),
Some("viewer@proton.me")
);
let account = store.resume().expect("resume").expect("signed in");
assert_eq!(account.username(), "viewer@proton.me");
}
#[tokio::test]
async fn signing_out_forgets_the_stored_session() {
let secrets = Arc::new(MemorySecrets::default());
secrets
.set(SESSION_KEY, &serde_json::to_string(&stored()).unwrap())
.unwrap();
let store = AccountStore::new(secrets);
store.sign_out(None).await.expect("sign out");
assert_eq!(store.username().expect("read"), None);
}
#[test]
fn the_stored_session_holds_no_password() {
let encoded = serde_json::to_string(&stored()).unwrap();
assert!(!encoded.contains("password\""), "{encoded}");
assert!(!encoded.contains("key_salts"), "{encoded}");
}
#[test]
fn a_session_stored_by_an_older_build_reads_as_signed_out() {
let secrets = Arc::new(MemorySecrets::default());
secrets
.set(
SESSION_KEY,
r#"{"session_id":"s","username":"u","user_id":"i","access_token":"a",
"refresh_token":"r","scopes":[],"password_mode":1,
"mailbox_password":"hunter2","key_salts":[]}"#,
)
.unwrap();
let store = AccountStore::new(secrets);
assert_eq!(store.username().expect("read"), None);
assert!(store.resume().expect("resume").is_none());
}
#[test]
fn a_stored_session_unlocks_with_its_passphrases() {
let unlock = stored().unlock();
assert_eq!(unlock.len(), 1);
assert_eq!(unlock.get("key-1"), Some(b"derived".as_slice()));
}
#[test]
fn a_blocked_sign_in_does_not_claim_the_app_is_outdated() {
let error = classify_sign_in_failure(ProtonError::Api(proton_sdk::error::ProtonApiError {
code: ResponseCode::Blocked,
http_status: 422,
message: "This version of the app is no longer supported".to_owned(),
details: None,
}));
assert!(
matches!(&error, Error::SignIn(text) if text == SIGN_IN_BLOCKED),
"{error}"
);
}
#[test]
fn a_stored_session_keeps_its_password_mode() {
let params = stored().resume_parameters();
assert_eq!(params.password_mode, PasswordMode::Dual);
assert!(!params.is_waiting_for_second_factor_code);
}
#[test]
fn a_verification_completion_yields_its_token() {
let raw =
r#"{"type":"HUMAN_VERIFICATION_SUCCESS","payload":{"token":"tok-1","type":"captcha"}}"#;
assert_eq!(verification_token(raw).as_deref(), Some("tok-1"));
let twice = r#""{\"type\":\"HUMAN_VERIFICATION_SUCCESS\",\"payload\":{\"token\":\"tok-1\",\"type\":\"captcha\"}}""#;
assert_eq!(verification_token(twice).as_deref(), Some("tok-1"));
}
#[test]
fn messages_that_are_not_a_verification_completion_are_ignored() {
for raw in [
r#"{"type":"resize","payload":{"height":400}}"#,
r#"{"type":"HUMAN_VERIFICATION_SUCCESS"}"#,
r#"{"type":"HUMAN_VERIFICATION_SUCCESS","payload":{"token":""}}"#,
"not json",
"",
] {
assert!(verification_token(raw).is_none(), "accepted: {raw}");
}
}
}