Merge F5 wallet digest RPC onto audit bundle

Keep sha3 (F4 checksums) and md-5 (HTTP Digest). Threat model: digest login
plus conjunctive verified receipts. Wallet tests: F1 matcher fixtures plus
F5 digest/cap coverage.

Cargo.lock

@@ -2359,6 +2359,16 @@ dependencies = [
  "regex-automata",
 ]
 
+[[package]]
+name = "md-5"
+version = "0.10.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d89e7ee0cfbedfc4da3340218492196241d89eefb6dab27de5df917a6d2e78cf"
+dependencies = [
+ "cfg-if",
+ "digest 0.10.7",
+]
+
 [[package]]
 name = "memchr"
 version = "2.8.3"
@@ -2626,6 +2636,7 @@ dependencies = [
  "chacha20poly1305",
  "ed25519-dalek",
  "futures",
+ "md-5",
  "rand 0.8.8",
  "ratatui",
  "rusqlite",

Cargo.toml

@@ -44,6 +44,7 @@ serde_json = "1"
 argon2 = "0.5"
 chacha20poly1305 = "0.10"
 sha3 = "0.10"
+md-5 = "0.10"
 
 [dev-dependencies]
 tempfile = "3"

README.md

@@ -162,13 +162,17 @@ If a peer’s onion is down, send fails. v1 has no outbox, no retry queue, no DH
 
 ## Monero sidecar
 
-OnionWire is not a wallet. Optional JSON-RPC to a user-hosted `monero-wallet-rpc`:
+OnionWire is not a wallet. Optional JSON-RPC to a user-hosted `monero-wallet-rpc`. The wallet **must** use `--rpc-login`; OnionWire refuses an open RPC (HTTP 200 without a Digest challenge) and refuses URLs with no credentials.
 
 ```bash
+# monero-wallet-rpc --rpc-bind-ip 127.0.0.1 --rpc-bind-port 18083 --rpc-login onionwire:secret
+export ONIONWIRE_WALLET_RPC=http://onionwire:secret@127.0.0.1:18083
+# or keep the password out of the URL:
 export ONIONWIRE_WALLET_RPC=http://127.0.0.1:18083
+export ONIONWIRE_WALLET_RPC_LOGIN=onionwire:secret
 ```
 
-Loopback or `.onion` only, HTTP, 5s timeout. Unset → chat still works; `/pay` and `/tip` say so.
+Loopback only, HTTP Digest (RFC 2617, matching `--rpc-login`), 5s timeout, 1 MiB response cap. `.onion` RPC URLs are rejected (no Arti dial; do not point this at a remote wallet). Unset → chat still works; `/pay` and `/tip` say so. Do not log the RPC password.
 
 - `/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.

docs/THREAT_MODEL.md

@@ -30,7 +30,7 @@ A signed `prf` frame is shown to people who already have a session with you. App
 
 ## Monero sidecar is not a wallet
 
-OnionWire never holds spend keys. Optional `ONIONWIRE_WALLET_RPC` talks HTTP to a user-hosted `monero-wallet-rpc`. A Noise friend can sign any `rcp`; the signature proves who sent the claim, not that a payment happened. `verified=1` only after a conjunctive RPC match: one `get_transfers` row with the same non-empty `txid`, `amount`, and `address`. Incoming `rcp` stays `verified=0` if RPC is down, errors, or no exact row. Subaddress reuse is the user’s wallet policy.
+OnionWire never holds spend keys. Optional `ONIONWIRE_WALLET_RPC` talks HTTP Digest to a user-hosted `monero-wallet-rpc` on loopback (`--rpc-login` required; open RPC is refused). A Noise friend can sign any `rcp`; the signature proves who sent the claim, not that a payment happened. `verified=1` only after a conjunctive RPC match: one `get_transfers` row with the same non-empty `txid`, `amount`, and `address`. Incoming `rcp` stays `verified=0` if RPC is down, errors, or no exact row. Subaddress reuse is the user’s wallet policy.
 
 ## Backup file is the identity
 

src/wallet.rs

@@ -1,5 +1,6 @@
 use std::time::Duration;
 
+use rand::RngCore;
 use tokio::io::{AsyncReadExt, AsyncWriteExt};
 use tokio::net::TcpStream;
 
@@ -16,11 +17,25 @@ impl std::fmt::Display for Error {
 
 impl std::error::Error for Error {}
 
-#[derive(Debug, Clone)]
+#[derive(Clone)]
 struct Endpoint {
     host: String,
     port: u16,
     path: String,
+    user: String,
+    pass: String,
+}
+
+impl std::fmt::Debug for Endpoint {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("Endpoint")
+            .field("host", &self.host)
+            .field("port", &self.port)
+            .field("path", &self.path)
+            .field("user", &self.user)
+            .field("pass", &"<redacted>")
+            .finish()
+    }
 }
 
 #[derive(Debug, Clone)]
@@ -44,20 +59,28 @@ impl Wallet {
 
     pub fn from_env() -> Self {
         match std::env::var("ONIONWIRE_WALLET_RPC") {
-            Ok(s) if !s.trim().is_empty() => match Self::from_url(s.trim()) {
+            Ok(s) if !s.trim().is_empty() => {
-                Ok(w) => w,
+                let login = std::env::var("ONIONWIRE_WALLET_RPC_LOGIN")
+                    .ok()
+                    .map(|v| v.trim().to_string())
+                    .filter(|v| !v.is_empty());
+                match parse_http_url(s.trim(), login.as_deref()) {
+                    Ok(endpoint) => Self {
+                        endpoint: Some(endpoint),
+                    },
                     Err(e) => {
                         eprintln!("ONIONWIRE_WALLET_RPC: {e}");
                         Self::disabled()
                     }
-            },
+                }
+            }
             _ => Self::disabled(),
         }
     }
 
     pub fn from_url(url: &str) -> Result<Self> {
         Ok(Self {
-            endpoint: Some(parse_http_url(url)?),
+            endpoint: Some(parse_http_url(url, None)?),
         })
     }
 
@@ -126,15 +149,26 @@ impl Wallet {
             "params": params,
         })
         .to_string();
-        let host_hdr = host_header(&ep.host, ep.port);
+        let raw = post_timeout(ep, &build_req(ep, &body, None)).await?;
-        let req = format!(
+        let status = http_status(&raw).unwrap_or(0);
-            "POST {} HTTP/1.1\r\nHost: {host_hdr}\r\nContent-Type: application/json\r\nContent-Length: {}\r\nConnection: close\r\n\r\n{body}",
+        if status == 200 {
-            ep.path,
+            return Err(Error(
-            body.len()
+                "wallet RPC requires digest auth (open RPC refused)".into(),
-        );
+            ));
-        let raw = tokio::time::timeout(RPC_TIMEOUT, http_post(ep, req.as_bytes()))
+        }
-            .await
+        if status != 401 {
-            .map_err(|_| Error("wallet RPC timed out".into()))??;
+            return parse_json_rpc(&raw);
+        }
+        let challenge = www_authenticate(&raw).ok_or_else(|| {
+            Error("wallet RPC digest required (--rpc-login / HTTP Digest)".into())
+        })?;
+        if !challenge.trim().to_ascii_lowercase().starts_with("digest") {
+            return Err(Error(
+                "wallet RPC digest required (--rpc-login / HTTP Digest)".into(),
+            ));
+        }
+        let auth = digest_authorization(ep, &challenge)?;
+        let raw = post_timeout(ep, &build_req(ep, &body, Some(&auth))).await?;
         parse_json_rpc(&raw)
     }
 }
@@ -147,13 +181,36 @@ pub fn transfers_match(rows: &[TransferRow], txid: &str, amount: &str, address:
         .any(|r| r.txid == txid && r.amount == amount && r.address == address)
 }
 
-fn parse_http_url(url: &str) -> Result<Endpoint> {
+fn credentials_required() -> Error {
+    Error("wallet RPC requires credentials (user:pass in URL or ONIONWIRE_WALLET_RPC_LOGIN)".into())
+}
+
+fn parse_login(login: &str) -> Result<(String, String)> {
+    let (user, pass) = login.split_once(':').ok_or_else(credentials_required)?;
+    if user.is_empty() || pass.is_empty() {
+        return Err(credentials_required());
+    }
+    Ok((user.to_string(), pass.to_string()))
+}
+
+fn parse_http_url(url: &str, extra_login: Option<&str>) -> Result<Endpoint> {
     let rest = url
         .strip_prefix("http://")
         .ok_or_else(|| Error("wallet RPC must be http:// (no TLS)".into()))?;
     if rest.contains("://") {
         return Err(Error("wallet RPC must be http:// (no TLS)".into()));
     }
+    let (userinfo, rest) = match rest.rsplit_once('@') {
+        Some((ui, hostpart)) => (Some(ui), hostpart),
+        None => (None, rest),
+    };
+    let (user, pass) = match userinfo {
+        Some(ui) => parse_login(ui)?,
+        None => match extra_login {
+            Some(login) => parse_login(login)?,
+            None => return Err(credentials_required()),
+        },
+    };
     let (hostport, path) = match rest.split_once('/') {
         Some((hp, p)) => (hp, format!("/{p}")),
         None => (rest, "/json_rpc".into()),
@@ -164,10 +221,21 @@ fn parse_http_url(url: &str) -> Result<Endpoint> {
         path
     };
     let (host, port) = parse_hostport(hostport)?;
-    if !allowed_host(&host) {
+    if host.trim().to_ascii_lowercase().ends_with(".onion") {
-        return Err(Error("wallet RPC host must be loopback or .onion".into()));
+        return Err(Error(
+            "wallet RPC over .onion is not supported (loopback only; no Arti dial)".into(),
+        ));
     }
-    Ok(Endpoint { host, port, path })
+    if !allowed_host(&host) {
+        return Err(Error("wallet RPC host must be loopback".into()));
+    }
+    Ok(Endpoint {
+        host,
+        port,
+        path,
+        user,
+        pass,
+    })
 }
 
 fn parse_hostport(hostport: &str) -> Result<(String, u16)> {
@@ -200,9 +268,6 @@ fn parse_port(p: &str) -> Result<u16> {
 
 fn allowed_host(host: &str) -> bool {
     let h = host.trim();
-    if h.to_ascii_lowercase().ends_with(".onion") {
-        return true;
-    }
     if h.eq_ignore_ascii_case("localhost") {
         return true;
     }
@@ -219,6 +284,31 @@ fn host_header(host: &str, port: u16) -> String {
     }
 }
 
+const MAX_RPC_BYTES: usize = 1024 * 1024;
+
+async fn post_timeout(ep: &Endpoint, req: &str) -> Result<Vec<u8>> {
+    tokio::time::timeout(RPC_TIMEOUT, http_post(ep, req.as_bytes()))
+        .await
+        .map_err(|_| Error("wallet RPC timed out".into()))?
+}
+
+fn build_req(ep: &Endpoint, body: &str, authorization: Option<&str>) -> String {
+    let host_hdr = host_header(&ep.host, ep.port);
+    let mut req = format!(
+        "POST {} HTTP/1.1\r\nHost: {host_hdr}\r\nContent-Type: application/json\r\nContent-Length: {}\r\nConnection: close\r\n",
+        ep.path,
+        body.len()
+    );
+    if let Some(auth) = authorization {
+        req.push_str("Authorization: ");
+        req.push_str(auth);
+        req.push_str("\r\n");
+    }
+    req.push_str("\r\n");
+    req.push_str(body);
+    req
+}
+
 async fn http_post(ep: &Endpoint, req: &[u8]) -> Result<Vec<u8>> {
     let mut stream = TcpStream::connect((ep.host.as_str(), ep.port))
         .await
@@ -228,13 +318,117 @@ async fn http_post(ep: &Endpoint, req: &[u8]) -> Result<Vec<u8>> {
         .await
         .map_err(|e| Error(format!("wallet write: {e}")))?;
     let mut buf = Vec::new();
-    stream
+    let mut tmp = [0u8; 8192];
-        .read_to_end(&mut buf)
+    loop {
+        let n = stream
+            .read(&mut tmp)
             .await
             .map_err(|e| Error(format!("wallet read: {e}")))?;
+        if n == 0 {
+            break;
+        }
+        if buf.len().saturating_add(n) > MAX_RPC_BYTES {
+            return Err(Error("wallet RPC response too large".into()));
+        }
+        buf.extend_from_slice(&tmp[..n]);
+    }
     Ok(buf)
 }
 
+fn http_status(raw: &[u8]) -> Option<u16> {
+    let text = std::str::from_utf8(raw).ok()?;
+    let line = text.lines().next()?;
+    let mut parts = line.split_whitespace();
+    let _http = parts.next()?;
+    parts.next()?.parse().ok()
+}
+
+fn www_authenticate(raw: &[u8]) -> Option<String> {
+    let text = std::str::from_utf8(raw).ok()?;
+    let (head, _) = text
+        .split_once("\r\n\r\n")
+        .or_else(|| text.split_once("\n\n"))?;
+    for line in head.lines().skip(1) {
+        let (k, v) = match line.split_once(':') {
+            Some(kv) => kv,
+            None => continue,
+        };
+        if k.eq_ignore_ascii_case("www-authenticate") {
+            return Some(v.trim().to_string());
+        }
+    }
+    None
+}
+
+fn digest_param(challenge: &str, key: &str) -> Option<String> {
+    let t = challenge.trim();
+    let rest = if t.len() >= 6 && t[..6].eq_ignore_ascii_case("digest") {
+        t[6..].trim()
+    } else {
+        return None;
+    };
+    for part in rest.split(',') {
+        let part = part.trim();
+        let (k, v) = match part.split_once('=') {
+            Some(kv) => kv,
+            None => continue,
+        };
+        if k.eq_ignore_ascii_case(key) {
+            return Some(v.trim().trim_matches('"').to_string());
+        }
+    }
+    None
+}
+
+fn md5_hex(s: &str) -> String {
+    use md5::{Digest, Md5};
+    hex_lower(&Md5::digest(s.as_bytes()))
+}
+
+fn hex_lower(bytes: &[u8]) -> String {
+    const H: &[u8; 16] = b"0123456789abcdef";
+    let mut out = String::with_capacity(bytes.len() * 2);
+    for &b in bytes {
+        out.push(H[(b >> 4) as usize] as char);
+        out.push(H[(b & 0xf) as usize] as char);
+    }
+    out
+}
+
+fn digest_authorization(ep: &Endpoint, challenge: &str) -> Result<String> {
+    if let Some(alg) = digest_param(challenge, "algorithm")
+        && !alg.eq_ignore_ascii_case("MD5")
+    {
+        return Err(Error("wallet RPC digest algorithm not MD5".into()));
+    }
+    let realm = digest_param(challenge, "realm").unwrap_or_default();
+    let nonce = digest_param(challenge, "nonce")
+        .ok_or_else(|| Error("wallet RPC digest required (--rpc-login / HTTP Digest)".into()))?;
+    let qop = digest_param(challenge, "qop");
+    let ha1 = md5_hex(&format!("{}:{realm}:{}", ep.user, ep.pass));
+    let ha2 = md5_hex(&format!("POST:{}", ep.path));
+    let (qop_part, resp) = if qop
+        .as_deref()
+        .is_some_and(|q| q.split(',').any(|x| x.trim() == "auth"))
+    {
+        let mut cnonce_bytes = [0u8; 8];
+        rand::thread_rng().fill_bytes(&mut cnonce_bytes);
+        let cnonce = hex_lower(&cnonce_bytes);
+        let nc = "00000001";
+        let response = md5_hex(&format!("{ha1}:{nonce}:{nc}:{cnonce}:auth:{ha2}"));
+        (
+            format!(", qop=auth, nc={nc}, cnonce=\"{cnonce}\""),
+            response,
+        )
+    } else {
+        (String::new(), md5_hex(&format!("{ha1}:{nonce}:{ha2}")))
+    };
+    Ok(format!(
+        "Digest username=\"{}\", realm=\"{realm}\", nonce=\"{nonce}\", uri=\"{}\", algorithm=MD5, response=\"{resp}\"{qop_part}",
+        ep.user, ep.path
+    ))
+}
+
 fn parse_json_rpc(raw: &[u8]) -> Result<serde_json::Value> {
     let text = std::str::from_utf8(raw).map_err(|_| Error("wallet RPC not UTF-8".into()))?;
     let (head, body) = text

tests/wallet.rs

@@ -30,13 +30,6 @@ fn json_rpc_ok(result: &str) -> String {
     )
 }
 
-async fn serve_once(listener: TcpListener, response: String) {
-    let (mut sock, _) = listener.accept().await.expect("accept");
-    let mut buf = vec![0u8; 4096];
-    let _ = sock.read(&mut buf).await;
-    sock.write_all(response.as_bytes()).await.expect("write");
-}
-
 #[test]
 fn disabled_create_address_is_not_configured() {
     let w = Wallet::disabled();
@@ -49,9 +42,19 @@ fn disabled_create_address_is_not_configured() {
     assert!(err.to_string().contains("not configured"), "got {err}");
 }
 
+#[test]
+fn refuse_url_without_credentials() {
+    let err = Wallet::from_url("http://127.0.0.1:18083").unwrap_err();
+    let msg = err.to_string().to_ascii_lowercase();
+    assert!(
+        msg.contains("credential") || msg.contains("login") || msg.contains("user"),
+        "got {err}"
+    );
+}
+
 #[test]
 fn refuse_non_loopback_non_onion_host() {
-    let err = Wallet::from_url("http://example.com:18083").unwrap_err();
+    let err = Wallet::from_url("http://ow:secret@example.com:18083").unwrap_err();
     assert!(
         err.to_string().to_ascii_lowercase().contains("host")
             || err.to_string().contains("loopback")
@@ -60,6 +63,34 @@ fn refuse_non_loopback_non_onion_host() {
     );
 }
 
+#[test]
+fn refuse_onion_rpc_url() {
+    let err = Wallet::from_url(
+        "http://ow:s3cretPASS@abcdefghijklmnopqrstuvwxyz234567abcdefghijklmnopqrstuvwxyz.onion:18083",
+    )
+    .unwrap_err();
+    let msg = err.to_string();
+    assert!(msg.to_ascii_lowercase().contains("onion"), "got {err}");
+    assert!(
+        !msg.contains("s3cretPASS"),
+        "password leaked in error: {err}"
+    );
+}
+
+#[test]
+fn password_absent_from_url_errors() {
+    let err = Wallet::from_url("http://ow:s3cretPASS@example.com:18083").unwrap_err();
+    assert!(
+        !err.to_string().contains("s3cretPASS"),
+        "password leaked in error: {err}"
+    );
+    let err = Wallet::from_url("http://ow:s3cretPASS@").unwrap_err();
+    assert!(
+        !err.to_string().contains("s3cretPASS"),
+        "password leaked in error: {err}"
+    );
+}
+
 #[tokio::test]
 async fn mock_get_address_parses_string() {
     let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
@@ -67,8 +98,8 @@ async fn mock_get_address_parses_string() {
     let canned = json_rpc_ok(
         r#"{"address":"4AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"}"#,
     );
-    tokio::spawn(serve_once(listener, canned));
+    tokio::spawn(serve_digest_then(listener, canned));
-    let w = Wallet::from_url(&format!("http://127.0.0.1:{}", addr.port())).unwrap();
+    let w = Wallet::from_url(&format!("http://ow:secret@127.0.0.1:{}", addr.port())).unwrap();
     let got = w.get_address().await.expect("get_address");
     assert!(got.starts_with('4'), "got {got}");
 }
@@ -80,15 +111,15 @@ async fn mock_create_address_and_transfer() {
     let canned = json_rpc_ok(
         r#"{"address":"8BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB","tx_hash":"abc123"}"#,
     );
-    tokio::spawn(serve_once(listener, canned.clone()));
+    tokio::spawn(serve_digest_then(listener, canned.clone()));
-    let w = Wallet::from_url(&format!("http://127.0.0.1:{}", addr.port())).unwrap();
+    let w = Wallet::from_url(&format!("http://ow:secret@127.0.0.1:{}", addr.port())).unwrap();
     let created = w.create_address().await.expect("create_address");
     assert!(created.starts_with('8'));
 
     let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
     let addr = listener.local_addr().unwrap();
-    tokio::spawn(serve_once(listener, canned));
+    tokio::spawn(serve_digest_then(listener, canned));
-    let w = Wallet::from_url(&format!("http://127.0.0.1:{}", addr.port())).unwrap();
+    let w = Wallet::from_url(&format!("http://ow:secret@127.0.0.1:{}", addr.port())).unwrap();
     let txid = w
         .transfer("8BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB", 1)
         .await
@@ -103,8 +134,8 @@ async fn mock_get_transfers_matches_txid() {
     let canned = json_rpc_ok(
         r#"{"in":[{"txid":"deadbeef","amount":5,"address":"8BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB"}],"pending":[]}"#,
     );
-    tokio::spawn(serve_once(listener, canned));
+    tokio::spawn(serve_digest_then(listener, canned));
-    let w = Wallet::from_url(&format!("http://127.0.0.1:{}", addr.port())).unwrap();
+    let w = Wallet::from_url(&format!("http://ow:secret@127.0.0.1:{}", addr.port())).unwrap();
     let rows = w.get_transfers().await.expect("get_transfers");
     assert!(wallet::transfers_match(
         &rows,
@@ -182,3 +213,67 @@ fn ingest_signed_receipt_mismatched_wallet_history_stays_unverified() {
     let rows = store.list_payments(&pk).unwrap();
     assert!(!rows[0].verified);
 }
+
+#[tokio::test]
+async fn oversized_rpc_response_is_err() {
+    let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
+    let addr = listener.local_addr().unwrap();
+    let huge = vec![b'A'; 2 * 1024 * 1024];
+    tokio::spawn(async move {
+        let (mut sock, _) = listener.accept().await.expect("accept");
+        let mut buf = vec![0u8; 4096];
+        let _ = sock.read(&mut buf).await;
+        sock.write_all(b"HTTP/1.1 200 OK\r\nContent-Type: text/plain\r\nConnection: close\r\n\r\n")
+            .await
+            .expect("hdr");
+        sock.write_all(&huge).await.expect("body");
+    });
+    let w = Wallet::from_url(&format!("http://ow:secret@127.0.0.1:{}", addr.port())).unwrap();
+    let err = w.get_address().await.unwrap_err();
+    let msg = err.to_string().to_ascii_lowercase();
+    assert!(
+        msg.contains("large") || msg.contains("size") || msg.contains("cap"),
+        "got {err}"
+    );
+    assert!(
+        !err.to_string().contains("secret"),
+        "password leaked: {err}"
+    );
+}
+
+fn digest_401() -> String {
+    "HTTP/1.1 401 Unauthorized\r\nWWW-Authenticate: Digest realm=\"monero-rpc\", nonce=\"abcnonce\", qop=\"auth\", algorithm=MD5\r\nContent-Length: 0\r\nConnection: close\r\n\r\n".into()
+}
+
+async fn serve_digest_then(listener: TcpListener, ok: String) {
+    let (mut sock, _) = listener.accept().await.expect("accept");
+    let mut buf = vec![0u8; 8192];
+    let _ = sock.read(&mut buf).await;
+    sock.write_all(digest_401().as_bytes()).await.expect("401");
+    drop(sock);
+
+    let (mut sock, _) = listener.accept().await.expect("accept2");
+    buf.fill(0);
+    let n = sock.read(&mut buf).await.unwrap_or(0);
+    let req = String::from_utf8_lossy(&buf[..n]);
+    assert!(
+        req.contains("Authorization: Digest"),
+        "missing digest auth: {req}"
+    );
+    assert!(req.contains("username=\"ow\""), "missing user: {req}");
+    assert!(req.contains("response=\""), "missing response: {req}");
+    sock.write_all(ok.as_bytes()).await.expect("200");
+}
+
+#[tokio::test]
+async fn mock_digest_auth_accepted() {
+    let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
+    let addr = listener.local_addr().unwrap();
+    let canned = json_rpc_ok(
+        r#"{"address":"4AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"}"#,
+    );
+    tokio::spawn(serve_digest_then(listener, canned));
+    let w = Wallet::from_url(&format!("http://ow:s3cretPASS@127.0.0.1:{}", addr.port())).unwrap();
+    let got = w.get_address().await.expect("get_address");
+    assert!(got.starts_with('4'), "got {got}");
+}