Implement signed API communication to improve security

Cargo.lock

@@ -3197,7 +3197,7 @@ checksum = "2304e00983f87ffb38b55b444b5e3b60a884b5d30c0fca7d82fe33449bbe55ea"
 
 [[package]]
 name = "hello-agent"
-version = "0.1.3"
+version = "0.1.4"
 dependencies = [
  "anyhow",
  "env_logger 0.10.2",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "hello-agent"
-version = "0.1.3"
+version = "0.1.4"
 edition = "2021"
 rust-version = "1.75"
 description = "Headless RustDesk-protocol-compatible support agent for Windows"

README.md

@@ -60,6 +60,11 @@ hello-agent.exe --server                       # user session, SYSTEM token
         │       └─ stamps `agent_name` / `agent_version` / `inventory`
         │          into each /api/sysinfo payload (re-uploads when the
         │          inventory collector below transitions empty → ready)
+        │       └─ signs every request with the device's Ed25519 sk
+        │          (same key rendezvous registers via RegisterPk).
+        │          The server's first valid sig flips that peer to
+        │          `managed=1` and unsigned posts get 401 from then on.
+        │          Spec: rustdesk-server/docs/AGENT-API-AUTH.md
         ├── inventory::collect_inventory             (background thread)
         │       └─ PowerShell + WMI + wlanapi + ipify → `INVENTORY` global
         │          consumed by hbbs_http::sync above; one-shot, no retry
@@ -115,6 +120,12 @@ inventory — keep it in sync when adding new patches.
      `--cm` process can plug a `MessageBoxW`-based `InvokeUiCM` into
      upstream's connection-manager IPC loop and inherit file-transfer,
      chat, and clipboard handling rather than re-implementing them.
+   * `mod hbbs_http` → `pub mod hbbs_http` so hello-agent's
+     `unattended_password::try_report` can reach
+     `librustdesk::hbbs_http::sign::build_signed_headers` — without
+     this the in-crate POST can't sign and the build fails with
+     `E0603: module 'hbbs_http' is private`. Tightly coupled to the
+     **Signed agent API** divergence below.
 2. **Build shape** — [`vendor/rustdesk/Cargo.toml`](vendor/rustdesk/Cargo.toml):
    `[lib] crate-type` reduced from `["cdylib", "staticlib", "rlib"]` to
    `["rlib"]`. We statically link the rlib into hello-agent.exe; the
@@ -148,6 +159,44 @@ inventory — keep it in sync when adding new patches.
    [`src/main.rs`](vendor/rustdesk/src/main.rs) (`.author(...)`).
    Cosmetic, but they show through in the Windows EXE metadata and
    in-app error dialogs.
+6. **Signed agent API** — every `POST /api/heartbeat`,
+   `POST /api/sysinfo`, and `POST /api/unattended-password` carries
+   two extra headers (`X-RD-Device-Id`,
+   `X-RD-Signature: v1.<ts>.<base64-ed25519-sig>`) so the server can
+   bind the request to the device's existing rendezvous keypair
+   instead of trusting the `id` + `uuid` body fields. Without this
+   patch, anyone who knows a peer's id and uuid can inject inventory,
+   heartbeats, and unattended-access passwords for it. Three patch
+   sites in the vendor tree (plus one in the hello-agent crate):
+   * New file
+     [`src/hbbs_http/sign.rs`](vendor/rustdesk/src/hbbs_http/sign.rs) —
+     the signer (`build_signed_headers`, `path_from_url`). Reads
+     `Config::get_key_pair()` and `Config::get_id()`; uses the
+     re-exported `hbb_common::sodiumoxide`.
+   * [`src/hbbs_http.rs`](vendor/rustdesk/src/hbbs_http.rs) — adds
+     `pub mod sign;` next to the existing module declarations.
+   * [`src/common.rs`](vendor/rustdesk/src/common.rs) — the
+     `post_request_` and `parse_simple_header` header-string parsers
+     now accept a `\n`-separated list of `Name: Value` lines so we
+     can pass both signing headers in one call. Old single-pair
+     callers parse identically — there's no newline to split on.
+   * [`src/hbbs_http/sync.rs`](vendor/rustdesk/src/hbbs_http/sync.rs)
+     call sites (the sysinfo POST around the sysinfo-version
+     comparison block, and the heartbeat POST a few dozen lines
+     later) — both build a signed-headers string via
+     `crate::hbbs_http::sign::build_signed_headers("POST",
+     &path_from_url(&url), body.as_bytes()).unwrap_or_default()`
+     and pass it to `post_request` instead of `""`.
+
+   And in the hello-agent crate proper (not the vendor tree, no
+   re-sync concern):
+   * [`src/unattended_password.rs`](src/unattended_password.rs) —
+     `try_report` also signs its `POST /api/unattended-password`
+     via `librustdesk::hbbs_http::sign::build_signed_headers`.
+
+   Matching server side: see rustdesk-server's
+   [`docs/AGENT-API-AUTH.md`](https://github.com/cstudio-ch/rustdesk-server/blob/pro-features/docs/AGENT-API-AUTH.md)
+   for the wire format and verification flow.
 
 ## Build
 

src/unattended_password.rs

@@ -111,7 +111,18 @@ async fn try_report(password: &str) -> Result<()> {
     })
     .to_string();
 
-    let resp = librustdesk::common::post_request(url, body, "")
+    // Same per-peer signature gate as heartbeat / sysinfo. Once this peer's
+    // `managed` flag has flipped to 1 server-side, unsigned posts here
+    // would be rejected — and we want unattended-password to keep landing
+    // through the same TOFU lifecycle as the other endpoints.
+    let headers = librustdesk::hbbs_http::sign::build_signed_headers(
+        "POST",
+        "/api/unattended-password",
+        body.as_bytes(),
+    )
+    .unwrap_or_default();
+
+    let resp = librustdesk::common::post_request(url, body, &headers)
         .await
         .map_err(|e| anyhow!("post: {e}"))?;
     let trimmed = resp.trim();

vendor/rustdesk/src/common.rs

@@ -1331,17 +1331,26 @@ async fn tcp_proxy_request(
 fn parse_simple_header(header: &str) -> Vec<HeaderEntry> {
     let mut entries = Vec::new();
     let mut has_content_type = false;
+    // Accept a `\n`-separated list of `Name: Value` pairs. Single-pair input
+    // (the historical shape) still parses correctly because there's no
+    // newline to split on.
     if !header.is_empty() {
-        let tmp: Vec<&str> = header.splitn(2, ": ").collect();
-        if tmp.len() == 2 {
-            if tmp[0].eq_ignore_ascii_case("Content-Type") {
-                has_content_type = true;
+        for line in header.split('\n') {
+            let line = line.trim();
+            if line.is_empty() {
+                continue;
+            }
+            let tmp: Vec<&str> = line.splitn(2, ": ").collect();
+            if tmp.len() == 2 {
+                if tmp[0].eq_ignore_ascii_case("Content-Type") {
+                    has_content_type = true;
+                }
+                entries.push(HeaderEntry {
+                    name: tmp[0].into(),
+                    value: tmp[1].into(),
+                    ..Default::default()
+                });
             }
-            entries.push(HeaderEntry {
-                name: tmp[0].into(),
-                value: tmp[1].into(),
-                ..Default::default()
-            });
         }
     }
     if !has_content_type {
@@ -1499,10 +1508,18 @@ async fn post_request_(
         danger_accept_invalid_cert.unwrap_or(false),
     )
     .post(url);
+    // `header` is a `\n`-separated list of `Name: Value` pairs. Single-pair
+    // callers (the original shape) work unchanged. The signed-API path uses
+    // this to pass both `X-RD-Device-Id` and `X-RD-Signature` at once.
     if !header.is_empty() {
-        let tmp: Vec<&str> = header.split(": ").collect();
-        if tmp.len() == 2 {
-            req = req.header(tmp[0], tmp[1]);
+        for line in header.split('\n') {
+            let line = line.trim();
+            if line.is_empty() {
+                continue;
+            }
+            if let Some((name, value)) = line.split_once(": ") {
+                req = req.header(name, value);
+            }
         }
     }
     req = req.header("Content-Type", "application/json");

vendor/rustdesk/src/hbbs_http.rs

@@ -7,6 +7,7 @@ pub mod account;
 pub mod downloader;
 mod http_client;
 pub mod record_upload;
+pub mod sign;
 pub mod sync;
 pub use http_client::{
     create_http_client_async, create_http_client_async_with_url, create_http_client_with_url,

vendor/rustdesk/src/hbbs_http/sign.rs

@@ -0,0 +1,72 @@
+//! Sign agent → server HTTP requests with the device's existing Ed25519
+//! keypair (the same one rendezvous uses for `RegisterPk`). Producing the
+//! header pair below for any signed call:
+//!
+//!   X-RD-Device-Id: <id>
+//!   X-RD-Signature: v1.<unix_ts>.<base64(ed25519_sig)>
+//!
+//! Server verifier: `/Users/sn0/Desktop/rustdesk-server/src/api/device_auth.rs`.
+//!
+//! Signed message format (must match the server byte-for-byte):
+//!   "rd-api-v1\n" || METHOD || "\n" || PATH || "\n" || TS || "\n" || sha256(body)
+
+use hbb_common::config::Config;
+use hbb_common::sodiumoxide::crypto::{hash::sha256, sign};
+
+/// Returns the two HTTP header lines joined by `\n`, ready to hand to
+/// `post_request`'s extended `header` parser. Returns `None` if the local
+/// keypair hasn't been generated yet (very early boot, before rendezvous) —
+/// the caller should fall back to an unsigned request in that case; the
+/// server's TOFU promote will still flip `managed=1` on the next signed
+/// request and any unsigned attempts after that flip will be rejected.
+pub fn build_signed_headers(method: &str, path: &str, body: &[u8]) -> Option<String> {
+    let (sk_bytes, _pk_bytes) = Config::get_key_pair();
+    if sk_bytes.is_empty() {
+        return None;
+    }
+    let sk = sign::SecretKey::from_slice(&sk_bytes)?;
+    let id = Config::get_id();
+    if id.is_empty() {
+        return None;
+    }
+    let ts = chrono::Utc::now().timestamp();
+
+    let body_sha = sha256::hash(body);
+    let ts_s = ts.to_string();
+    let mut msg = Vec::with_capacity(64 + method.len() + path.len());
+    msg.extend_from_slice(b"rd-api-v1\n");
+    msg.extend_from_slice(method.as_bytes());
+    msg.push(b'\n');
+    msg.extend_from_slice(path.as_bytes());
+    msg.push(b'\n');
+    msg.extend_from_slice(ts_s.as_bytes());
+    msg.push(b'\n');
+    msg.extend_from_slice(body_sha.as_ref());
+
+    let sig = sign::sign_detached(&msg, &sk);
+    let sig_b64 = crate::encode64(sig.as_ref());
+
+    Some(format!(
+        "X-RD-Device-Id: {}\nX-RD-Signature: v1.{}.{}",
+        id, ts, sig_b64
+    ))
+}
+
+/// Extract the `/path` portion of a full URL. Used to derive the signed
+/// path from sync.rs's `url` variable, which is always something like
+/// `https://server.example.com:21114/api/heartbeat`. Falls back to "/" if
+/// the URL doesn't parse — server-side verification will then fail, which
+/// is the right outcome (a malformed agent URL is a misconfiguration the
+/// operator should see).
+pub fn path_from_url(url: &str) -> String {
+    // Manual parse to avoid pulling in the `url` crate for one call. The
+    // structure is always scheme://host[:port]/path[?query]. Strip scheme,
+    // then take from the first '/' onward, then drop any '?query'.
+    let no_scheme = url.split_once("://").map(|(_, rest)| rest).unwrap_or(url);
+    let path_and_q = no_scheme.find('/').map(|i| &no_scheme[i..]).unwrap_or("/");
+    let path = path_and_q
+        .split_once('?')
+        .map(|(p, _)| p)
+        .unwrap_or(path_and_q);
+    path.to_string()
+}

vendor/rustdesk/src/hbbs_http/sync.rs

@@ -258,7 +258,15 @@ async fn start_hbbs_sync_async() {
                             }
                         }
                     }
-                    match crate::post_request(url.replace("heartbeat", "sysinfo"), v, "").await {
+                    let sysinfo_url = url.replace("heartbeat", "sysinfo");
+                    let sysinfo_path = crate::hbbs_http::sign::path_from_url(&sysinfo_url);
+                    let sysinfo_headers = crate::hbbs_http::sign::build_signed_headers(
+                        "POST",
+                        &sysinfo_path,
+                        v.as_bytes(),
+                    )
+                    .unwrap_or_default();
+                    match crate::post_request(sysinfo_url, v, &sysinfo_headers).await {
                         Ok(x)  => {
                             if x == "SYSINFO_UPDATED" {
                                 info_uploaded = InfoUploaded::uploaded(url.clone(), id.clone(), sys_username, had_inventory);
@@ -292,7 +300,15 @@ async fn start_hbbs_sync_async() {
                 }
                 let modified_at = LocalConfig::get_option("strategy_timestamp").parse::<i64>().unwrap_or(0);
                 v["modified_at"] = json!(modified_at);
-                if let Ok(s) = crate::post_request(url.clone(), v.to_string(), "").await {
+                let hb_body = v.to_string();
+                let hb_path = crate::hbbs_http::sign::path_from_url(&url);
+                let hb_headers = crate::hbbs_http::sign::build_signed_headers(
+                    "POST",
+                    &hb_path,
+                    hb_body.as_bytes(),
+                )
+                .unwrap_or_default();
+                if let Ok(s) = crate::post_request(url.clone(), hb_body, &hb_headers).await {
                     if let Ok(mut rsp) = serde_json::from_str::<HashMap::<&str, Value>>(&s) {
                         if rsp.remove("sysinfo").is_some() {
                             info_uploaded.uploaded = false;

vendor/rustdesk/src/lib.rs

@@ -72,7 +72,7 @@ pub mod ui_cm_interface;
 mod ui_interface;
 mod ui_session_interface;
 
-mod hbbs_http;
+pub mod hbbs_http;
 
 #[cfg(any(target_os = "windows", target_os = "linux", target_os = "macos"))]
 pub mod clipboard_file;