feat: incoming rate limit, identity backup, v0.2.0

App-level token bucket on rend accepts (30/60s, burst 10), panic-safe TUI restore, sqlite WAL + integrity_check fail-closed. Encrypted owbak1 identity backup/restore. README and threat model cover profile, XMR sidecar, backup, mixed-version frames.

Cargo.lock

@@ -134,6 +134,18 @@ dependencies = [
  "num-traits",
 ]
 
+[[package]]
+name = "argon2"
+version = "0.5.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3c3610892ee6e0cbce8ae2700349fcf8f98adb0dbfbee85aec3c9179d29cc072"
+dependencies = [
+ "base64ct",
+ "blake2",
+ "cpufeatures 0.2.17",
+ "password-hash",
+]
+
 [[package]]
 name = "arrayvec"
 version = "0.7.8"
@@ -762,6 +774,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "78c8292055d1c1df0cce5d180393dc8cce0abec0a7102adb6c7b1eef6016d60a"
 dependencies = [
  "generic-array",
+ "rand_core 0.6.4",
  "typenum",
 ]
 
@@ -2595,9 +2608,11 @@ dependencies = [
 
 [[package]]
 name = "onionwire"
-version = "0.1.2"
+version = "0.2.0"
 dependencies = [
+ "argon2",
  "arti-client",
+ "chacha20poly1305",
  "ed25519-dalek",
  "futures",
  "qrcode",
@@ -2789,6 +2804,17 @@ dependencies = [
  "windows-link",
 ]
 
+[[package]]
+name = "password-hash"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "346f04948ba92c43e8469c1ee6736c7563d71012b17d40745260fe106aac2166"
+dependencies = [
+ "base64ct",
+ "rand_core 0.6.4",
+ "subtle",
+]
+
 [[package]]
 name = "paste"
 version = "1.0.15"

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "onionwire"
-version = "0.1.2"
+version = "0.2.0"
 edition = "2024"
 rust-version = "1.91"
 description = "Lean Tor messenger: Arti in-process, identity=pubkey, onion=locator. No XMPP."
@@ -24,6 +24,8 @@ ratatui = { version = "0.30.2", default-features = false, features = ["crossterm
 x25519-dalek = { version = "2", features = ["static_secrets"] }
 snow = "0.10"
 serde_json = "1"
+argon2 = "0.5"
+chacha20poly1305 = "0.10"
 
 [dev-dependencies]
 tempfile = "3"

README.md

@@ -126,7 +126,8 @@ Focus starts on the composer so typing works immediately. `Tab` cycles panes; `j
 | `F2` | Share: terminal QR + payload |
 | `F3` | Paste a friend’s payload |
 | `F4` | Rotate **onion** (locator only) |
-| Enter | Run `/wipe` or `/wipe-all` from the composer |
+| `F5` | Selected friend’s profile (`/who`) |
+| Enter | Run `/wipe`, `/wipe-all`, `/profile`, `/who`, `/pay`, `/tip`, `/backup`, `/restore` from the composer |
 | `Esc` | Close overlay / back to Main / clear composer |
 | `Ctrl-Q` | Quit |
 
@@ -149,7 +150,37 @@ Focus starts on the composer so typing works immediately. `Tab` cycles panes; `j
 
 ## Fail closed
 
-If a peer’s onion is down, send fails. v1 has no outbox, no retry queue, no DHT, no name server.
+If a peer’s onion is down, send fails. v1 has no outbox, no retry queue, no DHT, no name server. There is still no hosted chat server.
+
+## Profile
+
+`/profile` edits your friend-visible display name, bio, and optional Monero address (64 / 512 byte limits, no images). Enter saves and one-shot sends a signed `prf` frame to the selected friend. `F5` or `/who` shows their last signed profile. There is no directory: unknown pubkeys are ignored.
+
+## Monero sidecar
+
+OnionWire is not a wallet. Optional JSON-RPC to a user-hosted `monero-wallet-rpc`:
+
+```bash
+export ONIONWIRE_WALLET_RPC=http://127.0.0.1:18083
+```
+
+Loopback or `.onion` only, HTTP, 5s timeout. Unset → chat still works; `/pay` and `/tip` say so.
+
+- `/pay <xmr> [memo]` — invoice (we want to receive). Uses a wallet subaddress if RPC is up, else the profile `xmr_addr`.
+- `/tip <xmr> [memo]` — pay the selected friend’s profile address, then send a signed `rcp`. Incoming receipts stay unverified until RPC `get_transfers` matches.
+
+## Backup / restore
+
+Losing `identity_sk` loses every friend relationship.
+
+- `/backup /path` — type `BACKUP`, passphrase twice. Writes `owbak1` (Argon2id + ChaCha20-Poly1305). Onion is **not** in the file (locator is disposable; F4 after restore if needed).
+- `/restore /path` — type `RESTORE`, passphrase. Overwrites self keys. **Does not rewrite the roster** — you may become a different person talking to old friends.
+
+Treat the backup file like the sqlite db.
+
+## Mixed versions
+
+0.1.2 peers store unknown plaintext as chat. A 0.2 sender of `prf ` / `inv ` / `rcp ` will leave a garbage line on an un-upgraded peer. Upgrade both sides. The Noise handshake is unchanged.
 
 ## Wipe
 

docs/THREAT_MODEL.md

@@ -22,6 +22,22 @@ The message log, identity secret key, and friend public keys sit on disk unencry
 
 Peer onion down → send fails. Fingerprint mismatch vs the pinned key → hard fail, no send. Arti HS experimental: if it cannot publish, OnionWire stops; it does not fall back to C-tor.
 
+## Profile is friend-visible, not a directory
+
+A signed `prf` frame is shown to people who already have a session with you. Apply only for existing friends. There is still no name lookup, DHT, or public profile server. Anyone who already has a Noise session can see the profile you send them; that is not confidentiality against that friend.
+
+## Monero sidecar is not a wallet
+
+OnionWire never holds spend keys. Optional `ONIONWIRE_WALLET_RPC` talks HTTP to a user-hosted `monero-wallet-rpc`. Never trust a `rcp` frame without RPC confirmation (`verified` stays 0). Subaddress reuse is the user’s wallet policy.
+
+## Backup file is the identity
+
+`/backup` writes the identity and Noise static secrets. Treat the file like `onionwire.db`. Restore overwrites self keys and does **not** rewrite the friends table.
+
+## Rate limit is availability, not anonymity
+
+Incoming rendezvous accepts are token-bucket limited (30/60s, burst 10). Excess is dropped without handshake. That is a DoS/availability control. It does not hide that you run an onion, and it is not a traffic-analysis defense.
+
 ## Out of v1
 
 Prosody, XMPP, s2s, MAM, carbons, outbox, multi-device, DHT / name server, sqlcipher.

src/backup.rs

@@ -0,0 +1,96 @@
+//! Encrypted identity backup. Onion (locator) is not included.
+
+use argon2::{Algorithm, Argon2, Params, Version};
+use chacha20poly1305::aead::{Aead, AeadCore, KeyInit, OsRng};
+use chacha20poly1305::{ChaCha20Poly1305, Key, Nonce};
+use rand::RngCore;
+
+pub const MAGIC: &[u8] = b"owbak1";
+const SALT_LEN: usize = 16;
+const NONCE_LEN: usize = 12;
+const KEY_LEN: usize = 32;
+const PLAIN_LEN: usize = KEY_LEN * 4;
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct BackupKeys {
+    pub identity_sk: [u8; 32],
+    pub identity_pk: [u8; 32],
+    pub prekey_sk: [u8; 32],
+    pub prekey_pk: [u8; 32],
+}
+
+impl BackupKeys {
+    pub fn to_bytes(&self) -> [u8; PLAIN_LEN] {
+        let mut out = [0u8; PLAIN_LEN];
+        out[0..32].copy_from_slice(&self.identity_sk);
+        out[32..64].copy_from_slice(&self.identity_pk);
+        out[64..96].copy_from_slice(&self.prekey_sk);
+        out[96..128].copy_from_slice(&self.prekey_pk);
+        out
+    }
+
+    pub fn from_bytes(b: &[u8]) -> Result<Self, String> {
+        if b.len() != PLAIN_LEN {
+            return Err("backup plaintext length".into());
+        }
+        Ok(Self {
+            identity_sk: b[0..32].try_into().unwrap(),
+            identity_pk: b[32..64].try_into().unwrap(),
+            prekey_sk: b[64..96].try_into().unwrap(),
+            prekey_pk: b[96..128].try_into().unwrap(),
+        })
+    }
+}
+
+fn kdf(passphrase: &str, salt: &[u8]) -> Result<[u8; 32], String> {
+    if passphrase.is_empty() {
+        return Err("empty passphrase".into());
+    }
+    if salt.len() != SALT_LEN {
+        return Err("salt length".into());
+    }
+    let params = Params::new(19_456, 2, 1, Some(32)).map_err(|e| e.to_string())?;
+    let argon = Argon2::new(Algorithm::Argon2id, Version::V0x13, params);
+    let mut key = [0u8; 32];
+    argon
+        .hash_password_into(passphrase.as_bytes(), salt, &mut key)
+        .map_err(|e| e.to_string())?;
+    Ok(key)
+}
+
+pub fn seal(passphrase: &str, keys: &BackupKeys) -> Result<Vec<u8>, String> {
+    let mut salt = [0u8; SALT_LEN];
+    rand::rngs::OsRng.fill_bytes(&mut salt);
+    let key = kdf(passphrase, &salt)?;
+    let cipher = ChaCha20Poly1305::new(Key::from_slice(&key));
+    let nonce = ChaCha20Poly1305::generate_nonce(&mut OsRng);
+    if nonce.len() != NONCE_LEN {
+        return Err("nonce length".into());
+    }
+    let ct = cipher
+        .encrypt(&nonce, keys.to_bytes().as_ref())
+        .map_err(|_| "encrypt failed".to_string())?;
+    let mut out = Vec::with_capacity(MAGIC.len() + SALT_LEN + NONCE_LEN + ct.len());
+    out.extend_from_slice(MAGIC);
+    out.extend_from_slice(&salt);
+    out.extend_from_slice(&nonce);
+    out.extend_from_slice(&ct);
+    Ok(out)
+}
+
+pub fn open(passphrase: &str, blob: &[u8]) -> Result<BackupKeys, String> {
+    let min = MAGIC.len() + SALT_LEN + NONCE_LEN + 16;
+    if blob.len() < min || !blob.starts_with(MAGIC) {
+        return Err("not an onionwire backup".into());
+    }
+    let salt = &blob[MAGIC.len()..MAGIC.len() + SALT_LEN];
+    let nonce_off = MAGIC.len() + SALT_LEN;
+    let nonce = Nonce::from_slice(&blob[nonce_off..nonce_off + NONCE_LEN]);
+    let ct = &blob[nonce_off + NONCE_LEN..];
+    let key = kdf(passphrase, salt)?;
+    let cipher = ChaCha20Poly1305::new(Key::from_slice(&key));
+    let pt = cipher
+        .decrypt(nonce, ct)
+        .map_err(|_| "wrong passphrase or corrupt backup".to_string())?;
+    BackupKeys::from_bytes(&pt)
+}

src/lib.rs

@@ -1,3 +1,4 @@
+pub mod backup;
 pub mod dispatch;
 pub mod frame;
 pub mod hs;
@@ -6,6 +7,7 @@ pub mod node;
 pub mod pay;
 pub mod profile;
 pub mod qr;
+pub mod ratelimit;
 pub mod session;
 mod store;
 pub mod tui;

src/node.rs

@@ -16,6 +16,7 @@ use crate::loc;
 use crate::pay;
 use crate::profile;
 use crate::qr;
+use crate::ratelimit::TokenBucket;
 use crate::session::{self, Keys};
 use crate::store::{Friend, FriendProfile, Message, PaymentWrite, Store};
 use crate::wallet::{self, Wallet};
@@ -42,8 +43,9 @@ pub struct Node {
     client: Client,
     hs: Mutex<Option<HsHandle>>,
     onion: Mutex<String>,
-    keys: Keys,
+    keys: Mutex<Keys>,
     wallet: Wallet,
+    incoming_limit: Mutex<TokenBucket>,
 }
 
 impl Node {
@@ -69,8 +71,9 @@ impl Node {
             client,
             hs: Mutex::new(None),
             onion: Mutex::new(onion),
-            keys,
+            keys: Mutex::new(keys),
             wallet: Wallet::from_env(),
+            incoming_limit: Mutex::new(TokenBucket::default()),
         });
         let rend = spawn_rend(Arc::clone(&node), rend);
         *node.hs.lock().map_err(|e| e.to_string())? = Some(HsHandle { _svc: svc, rend });
@@ -81,8 +84,15 @@ impl Node {
         self.onion.lock().map(|g| g.clone()).unwrap_or_default()
     }
 
+    fn keys(&self) -> Result<Keys, String> {
+        self.keys
+            .lock()
+            .map(|g| g.clone())
+            .map_err(|e| e.to_string())
+    }
+
     pub fn identity_pk(&self) -> [u8; 32] {
-        self.keys.identity_pk
+        self.keys().map(|k| k.identity_pk).unwrap_or([0; 32])
     }
 
     pub fn arti_dir(&self) -> PathBuf {
@@ -94,8 +104,48 @@ impl Node {
     }
 
     pub fn qr_payload(&self) -> Result<String, String> {
-        qr::encode(&self.keys.identity_sk, &self.onion(), &self.keys.prekey_pk)
-            .map_err(|e| e.to_string())
+        let k = self.keys()?;
+        qr::encode(&k.identity_sk, &self.onion(), &k.prekey_pk).map_err(|e| e.to_string())
+    }
+
+    pub fn write_backup(&self, path: &str, passphrase: &str) -> Result<(), String> {
+        use std::io::Write;
+        use std::os::unix::fs::OpenOptionsExt;
+        let k = self.keys()?;
+        let blob = crate::backup::seal(
+            passphrase,
+            &crate::backup::BackupKeys {
+                identity_sk: k.identity_sk,
+                identity_pk: k.identity_pk,
+                prekey_sk: k.prekey_sk,
+                prekey_pk: k.prekey_pk,
+            },
+        )?;
+        let mut f = std::fs::OpenOptions::new()
+            .write(true)
+            .create(true)
+            .truncate(true)
+            .mode(0o600)
+            .open(path)
+            .map_err(|e| e.to_string())?;
+        f.write_all(&blob).map_err(|e| e.to_string())
+    }
+
+    pub fn restore_backup(&self, path: &str, passphrase: &str) -> Result<(), String> {
+        let blob = std::fs::read(path).map_err(|e| e.to_string())?;
+        let k = crate::backup::open(passphrase, &blob)?;
+        self.store
+            .lock()
+            .map_err(|e| e.to_string())?
+            .replace_identity_keys(&k.identity_sk, &k.identity_pk, &k.prekey_sk, &k.prekey_pk)
+            .map_err(|e| e.to_string())?;
+        *self.keys.lock().map_err(|e| e.to_string())? = Keys {
+            identity_sk: k.identity_sk,
+            identity_pk: k.identity_pk,
+            prekey_sk: k.prekey_sk,
+            prekey_pk: k.prekey_pk,
+        };
+        Ok(())
     }
 
     pub fn add_friend_from_qr(&self, raw: &str) -> Result<(), String> {
@@ -187,8 +237,9 @@ impl Node {
     /// One-shot signed `prf` to a friend. Fail closed; no retry, no outbox.
     pub async fn push_self_profile(&self, friend_pk: &[u8]) -> Result<(), String> {
         let me = self.self_profile()?;
+        let k = self.keys()?;
         let prf = profile::sign(
-            &self.keys.identity_sk,
+            &k.identity_sk,
             &me.display_name,
             &me.bio,
             &me.xmr_addr,
@@ -214,7 +265,8 @@ impl Node {
         memo: &str,
     ) -> Result<(), String> {
         let address = self.invoice_address().await?;
-        let inv = pay::sign_invoice(&self.keys.identity_sk, atomic, &address, memo, unix_now())
+        let k = self.keys()?;
+        let inv = pay::sign_invoice(&k.identity_sk, atomic, &address, memo, unix_now())
             .map_err(|e| e.to_string())?;
         let pt = pay::encode_invoice(&inv);
         self.send_once(friend_pk, &pt).await?;
@@ -264,7 +316,8 @@ impl Node {
             .transfer(&address, amount)
             .await
             .map_err(|e| e.to_string())?;
-        let rcp = pay::sign_receipt(&self.keys.identity_sk, &txid, atomic, &address, unix_now())
+        let k = self.keys()?;
+        let rcp = pay::sign_receipt(&k.identity_sk, &txid, atomic, &address, unix_now())
             .map_err(|e| e.to_string())?;
         let pt = pay::encode_receipt(&rcp);
         self.send_once(friend_pk, &pt).await?;
@@ -360,7 +413,8 @@ impl Node {
         *self.onion.lock().map_err(|e| e.to_string())? = onion.clone();
 
         let ts = unix_now();
-        let loc = loc::sign(&self.keys.identity_sk, &onion, ts).map_err(|e| e.to_string())?;
+        let k = self.keys()?;
+        let loc = loc::sign(&k.identity_sk, &onion, ts).map_err(|e| e.to_string())?;
         let loc_pt = loc::encode(&loc);
         let friends = self
             .store
@@ -452,10 +506,10 @@ impl Node {
             .connect((onion, HS_PORT))
             .await
             .map_err(|e| format!("connect {onion}:{HS_PORT}: {e}"))?;
-        let mut sess =
-            session::handshake_initiator(&mut stream, &self.keys, pinned_id, remote_prekey)
-                .await
-                .map_err(session_err)?;
+        let keys = self.keys()?;
+        let mut sess = session::handshake_initiator(&mut stream, &keys, pinned_id, remote_prekey)
+            .await
+            .map_err(session_err)?;
         let ct = sess.encrypt(plaintext).map_err(session_err)?;
         frame::write_frame(&mut stream, &ct)
             .await
@@ -468,7 +522,8 @@ impl Node {
         S: AsyncRead + AsyncWrite + Unpin,
     {
         let store = &self.store;
-        let mut sess = session::handshake_responder(stream, &self.keys, |spk| {
+        let keys = self.keys()?;
+        let mut sess = session::handshake_responder(stream, &keys, |spk| {
             let Ok(g) = store.lock() else {
                 return None;
             };
@@ -630,6 +685,16 @@ fn spawn_rend(
     tokio::spawn(async move {
         let mut requests = std::pin::pin!(handle_rend_requests(rend));
         while let Some(req) = requests.next().await {
+            let allow = node
+                .incoming_limit
+                .lock()
+                .map(|mut b| b.try_acquire())
+                .unwrap_or(false);
+            if !allow {
+                eprintln!("rate-limit drop");
+                drop(req);
+                continue;
+            }
             let serve = Arc::clone(&node);
             tokio::spawn(async move {
                 let Ok(mut stream) = req.accept(Connected::new_empty()).await else {

src/ratelimit.rs

@@ -0,0 +1,45 @@
+//! App-level token bucket for incoming rendezvous accepts.
+
+use std::time::{Duration, Instant};
+
+pub struct TokenBucket {
+    rate_per_sec: f64,
+    burst: f64,
+    tokens: f64,
+    last: Instant,
+}
+
+impl TokenBucket {
+    /// `count` tokens replenished over `window`, starting full up to `burst`.
+    pub fn new(count: u32, window: Duration, burst: u32) -> Self {
+        let secs = window.as_secs_f64().max(f64::EPSILON);
+        Self {
+            rate_per_sec: f64::from(count) / secs,
+            burst: f64::from(burst),
+            tokens: f64::from(burst),
+            last: Instant::now(),
+        }
+    }
+
+    pub fn try_acquire(&mut self) -> bool {
+        self.try_acquire_at(Instant::now())
+    }
+
+    pub fn try_acquire_at(&mut self, now: Instant) -> bool {
+        let elapsed = now.saturating_duration_since(self.last).as_secs_f64();
+        self.last = now;
+        self.tokens = (self.tokens + elapsed * self.rate_per_sec).min(self.burst);
+        if self.tokens >= 1.0 {
+            self.tokens -= 1.0;
+            true
+        } else {
+            false
+        }
+    }
+}
+
+impl Default for TokenBucket {
+    fn default() -> Self {
+        Self::new(30, Duration::from_secs(60), 10)
+    }
+}

src/store.rs

@@ -104,6 +104,10 @@ impl Store {
         mkdir_700(&home.join("arti"))?;
         let db_path = home.join("onionwire.db");
         let conn = Connection::open(&db_path)?;
+        let journal: String = conn.query_row("PRAGMA journal_mode = WAL", [], |row| row.get(0))?;
+        if !journal.eq_ignore_ascii_case("wal") {
+            return Err(Error(format!("journal_mode WAL failed: {journal}")));
+        }
         conn.execute_batch(
             "
             PRAGMA foreign_keys = ON;
@@ -164,12 +168,43 @@ impl Store {
             INSERT OR IGNORE INTO self_profile (id) VALUES (1);
             ",
         )?;
+        let check: String = conn.query_row("PRAGMA integrity_check", [], |row| row.get(0))?;
+        if check != "ok" {
+            return Err(Error(format!("integrity_check: {check}")));
+        }
         let store = Self { conn };
         store.migrate()?;
         store.ensure_self()?;
         Ok(store)
     }
 
+    pub fn journal_mode(&self) -> Result<String> {
+        self.conn
+            .query_row("PRAGMA journal_mode", [], |row| row.get(0))
+            .map_err(Into::into)
+    }
+
+    pub fn replace_identity_keys(
+        &self,
+        identity_sk: &[u8],
+        identity_pk: &[u8],
+        prekey_sk: &[u8],
+        prekey_pk: &[u8],
+    ) -> Result<()> {
+        if identity_sk.len() != 32
+            || identity_pk.len() != 32
+            || prekey_sk.len() != 32
+            || prekey_pk.len() != 32
+        {
+            return Err(Error("identity key length".into()));
+        }
+        self.conn.execute(
+            "UPDATE self SET identity_sk = ?1, identity_pk = ?2, prekey_sk = ?3, prekey_pk = ?4 WHERE id = 1",
+            params![identity_sk, identity_pk, prekey_sk, prekey_pk],
+        )?;
+        Ok(())
+    }
+
     fn migrate(&self) -> Result<()> {
         self.add_column_if_missing(
             "friends",

src/tui.rs

@@ -68,6 +68,8 @@ OnionWire keys\n\
   /profile          edit name, bio, Monero address\n\
   /pay <xmr> [memo] invoice to receive\n\
   /tip <xmr> [memo] pay selected friend\n\
+  /backup /path     encrypted identity export\n\
+  /restore /path    overwrite self keys\n\
   ?                 this help\n\
   Ctrl-Q            quit\n\
 \n\
@@ -150,6 +152,8 @@ pub enum SlashCmd {
     Who,
     Pay { atomic: String, memo: String },
     Tip { atomic: String, memo: String },
+    Backup { path: String },
+    Restore { path: String },
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -261,9 +265,28 @@ pub fn parse_cmd(raw: &str) -> Option<SlashCmd> {
     {
         return parse_amount_cmd(rest).map(|(atomic, memo)| SlashCmd::Tip { atomic, memo });
     }
+    if let Some(rest) = s.strip_prefix("/backup")
+        && (rest.is_empty() || rest.starts_with(char::is_whitespace))
+    {
+        return parse_path_cmd(rest).map(|path| SlashCmd::Backup { path });
+    }
+    if let Some(rest) = s.strip_prefix("/restore")
+        && (rest.is_empty() || rest.starts_with(char::is_whitespace))
+    {
+        return parse_path_cmd(rest).map(|path| SlashCmd::Restore { path });
+    }
     None
 }
 
+fn parse_path_cmd(rest: &str) -> Option<String> {
+    let path = rest.trim();
+    if path.is_empty() {
+        None
+    } else {
+        Some(path.to_string())
+    }
+}
+
 fn parse_amount_cmd(rest: &str) -> Option<(String, String)> {
     let rest = rest.trim();
     if rest.is_empty() {
@@ -392,11 +415,96 @@ impl RotatePrompt {
     }
 }
 
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum BackupKind {
+    Backup,
+    Restore,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum BackupDecision {
+    Pending,
+    Confirm,
+    Cancel,
+}
+
+#[derive(Debug)]
+pub struct BackupPrompt {
+    expected: &'static str,
+    buf: String,
+}
+
+impl BackupPrompt {
+    pub fn backup() -> Self {
+        Self {
+            expected: "BACKUP",
+            buf: String::new(),
+        }
+    }
+
+    pub fn restore() -> Self {
+        Self {
+            expected: "RESTORE",
+            buf: String::new(),
+        }
+    }
+
+    pub fn on_esc(&self) -> BackupDecision {
+        BackupDecision::Cancel
+    }
+
+    pub fn on_char(&mut self, c: char) -> BackupDecision {
+        if c == '\n' {
+            return BackupDecision::Pending;
+        }
+        if c == '\u{8}' {
+            self.buf.pop();
+            return BackupDecision::Pending;
+        }
+        if !c.is_ascii_alphabetic() {
+            return BackupDecision::Pending;
+        }
+        self.buf.push(c);
+        if self.buf == self.expected {
+            BackupDecision::Confirm
+        } else {
+            BackupDecision::Pending
+        }
+    }
+
+    pub fn typed(&self) -> &str {
+        &self.buf
+    }
+}
+
+pub fn backup_screen_text() -> &'static str {
+    "Write encrypted identity backup?\n\
+This file is your identity secret. Treat it like the database.\n\
+Onion (locator) is not included.\n\
+Type BACKUP to confirm    Esc to cancel"
+}
+
+pub fn restore_screen_text() -> &'static str {
+    "Restore identity from backup?\n\
+This overwrites your self keys. It does not rewrite the roster.\n\
+You may become a different person with old friends.\n\
+Type RESTORE to confirm    Esc to cancel"
+}
+
+pub fn restore_terminal() {
+    ratatui::restore();
+}
+
 pub fn run(node: Arc<Node>, rt: tokio::runtime::Handle) -> Result<AppExit, String> {
+    let prev = std::panic::take_hook();
+    std::panic::set_hook(Box::new(move |info| {
+        restore_terminal();
+        prev(info);
+    }));
     let mut app = App::new(node, rt)?;
     let mut terminal = ratatui::init();
     let result = app.run(&mut terminal);
-    ratatui::restore();
+    restore_terminal();
     result
 }
 
@@ -419,12 +527,38 @@ struct App {
 
 enum Screen {
     Main,
-    Share { art: String, payload: String },
-    Paste { buf: String, err: Option<String> },
-    Approve { payload: QrPayload },
-    Rotate { prompt: RotatePrompt },
-    Wipe { kind: WipeKind, prompt: WipePrompt },
-    Profile { editor: ProfileEditor },
+    Share {
+        art: String,
+        payload: String,
+    },
+    Paste {
+        buf: String,
+        err: Option<String>,
+    },
+    Approve {
+        payload: QrPayload,
+    },
+    Rotate {
+        prompt: RotatePrompt,
+    },
+    Wipe {
+        kind: WipeKind,
+        prompt: WipePrompt,
+    },
+    Profile {
+        editor: ProfileEditor,
+    },
+    ConfirmKeys {
+        kind: BackupKind,
+        path: String,
+        prompt: BackupPrompt,
+    },
+    Passphrase {
+        kind: BackupKind,
+        path: String,
+        first: Option<String>,
+        buf: String,
+    },
 }
 
 impl App {
@@ -545,6 +679,22 @@ impl App {
                         self.composer.clear();
                         tip_cmd = Some((atomic, memo));
                     }
+                    Some(SlashCmd::Backup { path }) => {
+                        self.composer.clear();
+                        self.screen = Screen::ConfirmKeys {
+                            kind: BackupKind::Backup,
+                            path,
+                            prompt: BackupPrompt::backup(),
+                        };
+                    }
+                    Some(SlashCmd::Restore { path }) => {
+                        self.composer.clear();
+                        self.screen = Screen::ConfirmKeys {
+                            kind: BackupKind::Restore,
+                            path,
+                            prompt: BackupPrompt::restore(),
+                        };
+                    }
                     None => {}
                 },
                 KeyCode::Char(c) if !key.modifiers.contains(KeyModifiers::CONTROL) => {
@@ -619,6 +769,48 @@ impl App {
                 }
                 _ => {}
             },
+            Screen::ConfirmKeys { kind, path, prompt } => {
+                let kind = *kind;
+                match key.code {
+                    KeyCode::Esc => self.screen = Screen::Main,
+                    KeyCode::Char(c) if !key.modifiers.contains(KeyModifiers::CONTROL) => {
+                        if prompt.on_char(c) == BackupDecision::Confirm {
+                            self.screen = Screen::Passphrase {
+                                kind,
+                                path: path.clone(),
+                                first: None,
+                                buf: String::new(),
+                            };
+                        }
+                    }
+                    KeyCode::Backspace => {
+                        prompt.on_char('\u{8}');
+                    }
+                    _ => {}
+                }
+            }
+            Screen::Passphrase {
+                kind,
+                path,
+                first,
+                buf,
+            } => match key.code {
+                KeyCode::Esc => self.screen = Screen::Main,
+                KeyCode::Backspace => {
+                    buf.pop();
+                }
+                KeyCode::Enter => {
+                    let kind = *kind;
+                    let path = path.clone();
+                    let first = first.clone();
+                    let pass = buf.clone();
+                    self.submit_passphrase(kind, &path, first.as_deref(), &pass)?;
+                }
+                KeyCode::Char(c) if !key.modifiers.contains(KeyModifiers::CONTROL) => {
+                    buf.push(c);
+                }
+                _ => {}
+            },
         }
         if let Some(kind) = wipe_confirm {
             return self.confirm_wipe(kind);
@@ -719,6 +911,55 @@ impl App {
         }
     }
 
+    fn submit_passphrase(
+        &mut self,
+        kind: BackupKind,
+        path: &str,
+        first: Option<&str>,
+        pass: &str,
+    ) -> Result<(), String> {
+        match kind {
+            BackupKind::Backup => {
+                if let Some(first) = first {
+                    if first != pass {
+                        self.alert = Some("passphrases do not match".into());
+                        self.screen = Screen::Main;
+                        return Ok(());
+                    }
+                    match self.node.write_backup(path, pass) {
+                        Ok(()) => {
+                            self.status_note = Some(format!("backup written {path}"));
+                            self.screen = Screen::Main;
+                        }
+                        Err(e) => {
+                            self.alert = Some(e);
+                            self.screen = Screen::Main;
+                        }
+                    }
+                } else {
+                    self.screen = Screen::Passphrase {
+                        kind,
+                        path: path.to_string(),
+                        first: Some(pass.to_string()),
+                        buf: String::new(),
+                    };
+                }
+            }
+            BackupKind::Restore => match self.node.restore_backup(path, pass) {
+                Ok(()) => {
+                    self.me_fp = to_hex(&self.node.identity_pk());
+                    self.status_note = Some("identity restored — roster unchanged".into());
+                    self.screen = Screen::Main;
+                }
+                Err(e) => {
+                    self.alert = Some(e);
+                    self.screen = Screen::Main;
+                }
+            },
+        }
+        Ok(())
+    }
+
     fn confirm_rotate(&mut self) -> Result<(), String> {
         let node = Arc::clone(&self.node);
         match self.rt.block_on(node.rotate()) {
@@ -855,6 +1096,10 @@ impl App {
             Screen::Rotate { prompt } => draw_rotate(f, prompt.typed()),
             Screen::Wipe { kind, prompt } => draw_wipe(f, *kind, prompt.typed()),
             Screen::Profile { editor } => draw_profile(f, editor),
+            Screen::ConfirmKeys { kind, prompt, .. } => draw_confirm_keys(f, *kind, prompt.typed()),
+            Screen::Passphrase {
+                kind, first, buf, ..
+            } => draw_passphrase(f, *kind, first.is_some(), buf),
         }
         if self.help_open {
             draw_text_overlay(f, "? help", help_overlay_text());
@@ -1094,6 +1339,11 @@ fn footer_hints(screen: &Screen) -> &'static str {
             WipeKind::All => "type WIPEALL  Esc cancel  ? help",
         },
         Screen::Profile { .. } => "Enter save  Tab field  Esc cancel  ? help",
+        Screen::ConfirmKeys { kind, .. } => match kind {
+            BackupKind::Backup => "type BACKUP  Esc cancel  ? help",
+            BackupKind::Restore => "type RESTORE  Esc cancel  ? help",
+        },
+        Screen::Passphrase { .. } => "Enter submit  Esc cancel  ? help",
     }
 }
 
@@ -1194,6 +1444,38 @@ fn draw_profile(f: &mut Frame, editor: &ProfileEditor) {
     );
 }
 
+fn draw_confirm_keys(f: &mut Frame, kind: BackupKind, typed: &str) {
+    let (title, text) = match kind {
+        BackupKind::Backup => ("(o) backup", backup_screen_text()),
+        BackupKind::Restore => ("(o) restore", restore_screen_text()),
+    };
+    let body = format!("{text}\n\n{typed}");
+    f.render_widget(
+        Paragraph::new(body)
+            .style(Style::default().fg(C_TEXT))
+            .wrap(Wrap { trim: false })
+            .block(themed_block(title)),
+        f.area(),
+    );
+}
+
+fn draw_passphrase(f: &mut Frame, kind: BackupKind, second: bool, buf: &str) {
+    let stars: String = buf.chars().map(|_| '*').collect();
+    let hint = match (kind, second) {
+        (BackupKind::Backup, false) => "Enter passphrase",
+        (BackupKind::Backup, true) => "Re-enter passphrase",
+        (BackupKind::Restore, _) => "Enter passphrase",
+    };
+    let body = format!("{hint}\n\n{stars}\n\nEnter submit    Esc cancel");
+    f.render_widget(
+        Paragraph::new(body)
+            .style(Style::default().fg(C_TEXT))
+            .wrap(Wrap { trim: false })
+            .block(themed_block("(o) passphrase")),
+        f.area(),
+    );
+}
+
 fn draw_text_overlay(f: &mut Frame, title: &str, text: &str) {
     let area = f.area();
     let lines = text.lines().count() as u16 + 2;

tests/backup.rs

@@ -0,0 +1,135 @@
+//! Encrypted identity backup: owbak1 || salt[16] || nonce[12] || ciphertext.
+
+use onionwire::Store;
+use onionwire::backup::{self, BackupKeys};
+use onionwire::tui::{
+    BackupDecision, BackupPrompt, SlashCmd, backup_screen_text, parse_cmd, restore_screen_text,
+};
+
+fn keys(tag: u8) -> BackupKeys {
+    BackupKeys {
+        identity_sk: [tag; 32],
+        identity_pk: [tag.wrapping_add(1); 32],
+        prekey_sk: [tag.wrapping_add(2); 32],
+        prekey_pk: [tag.wrapping_add(3); 32],
+    }
+}
+
+#[test]
+fn roundtrip_keys() {
+    let k = keys(7);
+    let blob = backup::seal("correct horse", &k).expect("seal");
+    assert!(blob.starts_with(b"owbak1"), "magic");
+    assert_eq!(&blob[0..6], b"owbak1");
+    let opened = backup::open("correct horse", &blob).expect("open");
+    assert_eq!(opened.identity_sk, k.identity_sk);
+    assert_eq!(opened.identity_pk, k.identity_pk);
+    assert_eq!(opened.prekey_sk, k.prekey_sk);
+    assert_eq!(opened.prekey_pk, k.prekey_pk);
+}
+
+#[test]
+fn onion_is_not_in_backup() {
+    let k = keys(3);
+    let blob = backup::seal("pw", &k).unwrap();
+    let onion = b"abcdefghijklmnopqrstuvwxyz234567abcdefghijklmnopq.onion";
+    assert!(
+        !blob.windows(onion.len()).any(|w| w == onion),
+        "locator must not be in the backup file"
+    );
+}
+
+#[test]
+fn wrong_passphrase_fails() {
+    let blob = backup::seal("right", &keys(1)).unwrap();
+    assert!(backup::open("wrong", &blob).is_err());
+}
+
+#[test]
+fn garbage_file_fails() {
+    assert!(backup::open("pw", b"nope").is_err());
+    assert!(backup::open("pw", b"owbak1").is_err());
+    let mut blob = backup::seal("pw", &keys(2)).unwrap();
+    blob.push(0xff);
+    assert!(backup::open("pw", &blob).is_err());
+}
+
+#[test]
+fn restore_overwrites_self_keys_friends_stay() {
+    let dir = tempfile::tempdir().expect("tempdir");
+    let store = Store::open_at(dir.path()).expect("open");
+    store
+        .upsert_friend(&[9u8; 32], "alice.onion", Some("alice"))
+        .unwrap();
+    let old = store.self_identity().unwrap();
+    let incoming = keys(42);
+    store
+        .replace_identity_keys(
+            &incoming.identity_sk,
+            &incoming.identity_pk,
+            &incoming.prekey_sk,
+            &incoming.prekey_pk,
+        )
+        .unwrap();
+    let me = store.self_identity().unwrap();
+    assert_eq!(me.identity_sk, incoming.identity_sk);
+    assert_eq!(me.identity_pk, incoming.identity_pk);
+    assert_eq!(me.prekey_sk, incoming.prekey_sk);
+    assert_eq!(me.prekey_pk, incoming.prekey_pk);
+    assert_eq!(me.onion, old.onion, "onion is locator, not restored");
+    assert_eq!(store.friend_count().unwrap(), 1);
+    let f = store.get_friend(&[9u8; 32]).unwrap().unwrap();
+    assert_eq!(f.petname.as_deref(), Some("alice"));
+}
+
+#[test]
+fn slash_backup_restore() {
+    assert_eq!(
+        parse_cmd("/backup /tmp/id.owbak"),
+        Some(SlashCmd::Backup {
+            path: "/tmp/id.owbak".into()
+        })
+    );
+    assert_eq!(
+        parse_cmd("  /restore /tmp/id.owbak  "),
+        Some(SlashCmd::Restore {
+            path: "/tmp/id.owbak".into()
+        })
+    );
+    assert_eq!(parse_cmd("/backup"), None);
+    assert_eq!(parse_cmd("/restore"), None);
+}
+
+#[test]
+fn backup_requires_typing_not_enter() {
+    let mut p = BackupPrompt::backup();
+    assert_eq!(p.on_esc(), BackupDecision::Cancel);
+    assert_eq!(p.on_char('\n'), BackupDecision::Pending);
+    for c in "BACKU".chars() {
+        assert_eq!(p.on_char(c), BackupDecision::Pending);
+    }
+    assert_eq!(p.on_char('P'), BackupDecision::Confirm);
+}
+
+#[test]
+fn restore_requires_typing_restore() {
+    let mut p = BackupPrompt::restore();
+    assert_eq!(p.on_char('\n'), BackupDecision::Pending);
+    for c in "RESTOR".chars() {
+        assert_eq!(p.on_char(c), BackupDecision::Pending);
+    }
+    assert_eq!(p.on_char('E'), BackupDecision::Confirm);
+}
+
+#[test]
+fn restore_screen_warns_roster_stays() {
+    let t = restore_screen_text();
+    assert!(t.contains("does not rewrite the roster"), "{t}");
+    assert!(t.contains("Type RESTORE to confirm"), "{t}");
+    let b = backup_screen_text();
+    assert!(
+        t.contains("different person") || b.contains("identity"),
+        "{t}\n{b}"
+    );
+    assert!(b.contains("Type BACKUP to confirm"), "{b}");
+}

tests/ratelimit.rs

@@ -0,0 +1,28 @@
+//! Incoming rend accepts: 30 / 60s, burst 10.
+
+use std::time::{Duration, Instant};
+
+use onionwire::ratelimit::TokenBucket;
+
+#[test]
+fn burst_allows_then_denies() {
+    let t0 = Instant::now();
+    let mut b = TokenBucket::new(30, Duration::from_secs(60), 10);
+    for _ in 0..10 {
+        assert!(b.try_acquire_at(t0), "burst of 10 must pass");
+    }
+    assert!(!b.try_acquire_at(t0), "11th in the burst must drop");
+}
+
+#[test]
+fn refill_one_token_after_two_seconds() {
+    let t0 = Instant::now();
+    let mut b = TokenBucket::new(30, Duration::from_secs(60), 10);
+    for _ in 0..10 {
+        assert!(b.try_acquire_at(t0));
+    }
+    // 30 tokens / 60s = 0.5/s → 2s yields one token.
+    let t1 = t0 + Duration::from_secs(2);
+    assert!(b.try_acquire_at(t1));
+    assert!(!b.try_acquire_at(t1));
+}

tests/store.rs

@@ -163,3 +163,17 @@ fn friend_prekey_lookup() {
     assert_eq!(f.pubkey, pk(1));
     assert_eq!(f.prekey, spk);
 }
+
+#[test]
+fn open_uses_wal_journal() {
+    let dir = tempfile::tempdir().expect("tempdir");
+    let store = Store::open_at(dir.path()).expect("open");
+    assert_eq!(store.journal_mode().unwrap().to_ascii_lowercase(), "wal");
+}
+
+#[test]
+fn corrupt_db_fails_closed() {
+    let dir = tempfile::tempdir().expect("tempdir");
+    std::fs::write(dir.path().join("onionwire.db"), b"not a sqlite database").unwrap();
+    assert!(Store::open_at(dir.path()).is_err());
+}

tests/tui_chrome.rs

@@ -39,7 +39,8 @@ fn help_overlay_lists_core_bindings() {
     let help = help_overlay_text();
     assert!(!help.is_empty());
     for needle in [
-        "Tab", "F2", "F3", "F4", "F5", "/profile", "/pay", "/tip", "Ctrl-Q", "?",
+        "Tab", "F2", "F3", "F4", "F5", "/profile", "/pay", "/tip", "/backup", "/restore", "Ctrl-Q",
+        "?",
     ] {
         assert!(help.contains(needle), "help overlay missing {needle:?}");
     }
@@ -156,3 +157,8 @@ fn pane_focus_cycles_roster_chat_composer() {
     assert_eq!(Pane::Chat.prev(), Pane::Roster);
     assert_eq!(Pane::Composer.prev(), Pane::Chat);
 }
+
+#[test]
+fn restore_terminal_is_callable_without_panic() {
+    onionwire::tui::restore_terminal();
+}