Files
PiCloud/crates/picloud/tests/email_inbound.rs
MechaCat02 8b5a02b3ef fix(audit-2026-06-11/H-B2): inbound_secret mandatory + bad-signature lockout on email triggers
Two gaps:

1. /api/v1/admin/apps/{id}/triggers/email accepted `inbound_secret: null`
   and treated it as "this trigger is unsigned". The runtime then
   skipped HMAC verification entirely. URL discovery (logs, ops
   dashboards, bruteforce on the 122-bit TriggerId space) then fan-out-
   amplified into the outbox for free — anonymous DoS via the
   dispatcher.

2. Even signed triggers had no per-trigger rate limit on signature-
   verify failures, so an attacker who knew the URL could pump unsigned
   POSTs to force Argon2-equivalent work (HMAC verify + nonce-dedup +
   stored-secret decrypt) at line rate.

Fix:

* triggers_api::create_email_trigger now requires a non-empty
  inbound_secret. 400 on missing / empty / whitespace-only.
* email_inbound_api::receive_inbound_email returns 401 immediately when
  the resolved target has no inbound_secret_encrypted column (pre-fix
  rows). The previous `if let Some(ct), Some(nonce)` branch is gone.
* New `BadSignatureLimiter`: per-`(app_id, trigger_id)` sliding-window
  bucket (10 fails / 60 s). On lockout the receiver returns 429 with
  Retry-After instead of 401. record_failure runs on both the
  "no-secret" 401 path and any verify_signature failure.

Test fallout:
* email_inbound integration tests that relied on None secret: removed
  the now-impossible `unsigned_trigger_accepts_without_signature` test,
  replaced with `create_without_inbound_secret_is_rejected` covering
  null / "" / "   "; updated `malformed_body_is_422` and
  `cross_app_path_is_404` to pass + sign with a secret.
* Two new unit tests pin the limiter behavior (burst lockout + per-
  trigger independence).

Audit refs: security_audit/08_dos_resource.md#h-3,
security_audit/09_external_integrations.md#f-ext-m-001.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-06-11 20:49:31 +02:00

330 lines
12 KiB
Rust

//! End-to-end tests for the inbound-email webhook receiver (v1.1.7).
//!
//! Gated on `DATABASE_URL` like `dispatcher_e2e.rs`: when unset the test
//! prints a notice and returns early so plain `cargo test` stays green.
//!
//! Covers the receiver's status-code matrix (202 / 401 / 404 / 422),
//! cross-app path isolation, HMAC verification (signed + unsigned
//! triggers), the dispatcher routing the `email` outbox row, and the
//! handler actually firing with `ctx.event.email` populated. The
//! "handler fired" observation uses the same KV-marker pattern as
//! `dispatcher_e2e.rs`.
#![allow(clippy::needless_pass_by_value)]
use std::time::Duration;
use axum_test::TestServer;
use hmac::{Hmac, Mac};
use serde_json::{json, Value};
use sha2::Sha256;
use sqlx::postgres::PgPoolOptions;
use sqlx::PgPool;
use uuid::Uuid;
/// Fixed master key so the receiver decrypts the inbound_secret the
/// admin endpoint encrypted (same key feeds build_app + the admin path).
fn master_key() -> picloud_shared::MasterKey {
picloud_shared::MasterKey::from_bytes([0x42u8; 32])
}
async fn pool_or_skip() -> Option<PgPool> {
let Ok(url) = std::env::var("DATABASE_URL") else {
eprintln!("email_inbound: DATABASE_URL unset — skipping");
return None;
};
let pool = PgPoolOptions::new()
.max_connections(5)
.connect(&url)
.await
.expect("connect to DATABASE_URL");
sqlx::migrate!("../manager-core/migrations")
.run(&pool)
.await
.expect("apply migrations");
Some(pool)
}
async fn server_for(pool: PgPool, suffix: &str) -> (TestServer, String) {
use picloud_manager_core::auth::hash_password;
use picloud_shared::InstanceRole;
let unique = format!("{suffix}-{}", Uuid::new_v4().simple());
let auth = picloud::AuthDeps::from_pool(pool.clone());
let username = format!("eml-{unique}");
let hash = hash_password("pw").expect("hash");
auth.users
.create(&username, &hash, InstanceRole::Owner, None)
.await
.expect("seed admin");
let app = picloud::build_app(pool, auth, master_key())
.await
.expect("build_app");
let mut server = TestServer::new(app).expect("TestServer");
let resp = server
.post("/api/v1/admin/auth/login")
.json(&json!({ "username": username, "password": "pw" }))
.await;
resp.assert_status_ok();
let token = resp.json::<Value>()["token"]
.as_str()
.expect("login token")
.to_string();
server.add_header("authorization", format!("Bearer {token}"));
let slug = format!("eml-{unique}");
let created: Value = server
.post("/api/v1/admin/apps")
.json(&json!({ "slug": slug, "name": slug }))
.await
.json();
let app_id = created["id"].as_str().expect("app id").to_string();
(server, app_id)
}
async fn create_script(server: &TestServer, app_id: &str, name: &str, source: &str) -> String {
let created: Value = server
.post("/api/v1/admin/scripts")
.json(&json!({ "app_id": app_id, "name": name, "source": source }))
.await
.json();
created["id"].as_str().expect("script id").to_string()
}
const MARKER_HANDLER: &str = r#"
let e = ctx.event;
kv::collection("e2e_markers").set("marker", e);
#{ ok: true }
"#;
async fn create_email_trigger(
server: &TestServer,
app_id: &str,
script_id: &str,
secret: Option<&str>,
) -> String {
let created: Value = server
.post(&format!("/api/v1/admin/apps/{app_id}/triggers/email"))
.json(&json!({ "script_id": script_id, "inbound_secret": secret }))
.await
.json();
created["id"].as_str().expect("trigger id").to_string()
}
fn sign(secret: &str, ts: i64, body: &str) -> String {
let mut mac = Hmac::<Sha256>::new_from_slice(secret.as_bytes()).expect("hmac key");
mac.update(ts.to_string().as_bytes());
mac.update(b".");
mac.update(body.as_bytes());
hex::encode(mac.finalize().into_bytes())
}
fn now_ts() -> i64 {
chrono::Utc::now().timestamp()
}
async fn poll_marker(pool: &PgPool, app_id: &str) -> Option<Value> {
let app_uuid = Uuid::parse_str(app_id).expect("app uuid");
for _ in 0..100 {
let row: Option<(Value,)> = sqlx::query_as(
"SELECT value FROM kv_entries \
WHERE app_id = $1 AND collection = 'e2e_markers' AND key = 'marker'",
)
.bind(app_uuid)
.fetch_optional(pool)
.await
.expect("query marker");
if let Some((value,)) = row {
return Some(value);
}
tokio::time::sleep(Duration::from_millis(100)).await;
}
None
}
const BODY: &str = r#"{"from":"sender@external.com","to":["alice@myapp.com"],"cc":["bob@myapp.com"],"subject":"Re: question","text":"hello there","message_id":"<abc@external.com>"}"#;
#[tokio::test]
async fn signed_post_accepts_and_fires_handler() {
let Some(pool) = pool_or_skip().await else {
return;
};
let (server, app_id) = server_for(pool.clone(), "signed").await;
let handler = create_script(&server, &app_id, "eml-handler", MARKER_HANDLER).await;
let trigger = create_email_trigger(&server, &app_id, &handler, Some("topsecret")).await;
let ts = now_ts();
let sig = sign("topsecret", ts, BODY);
server
.post(&format!("/api/v1/email-inbound/{app_id}/{trigger}"))
.add_header("x-picloud-signature", sig)
.add_header("x-picloud-timestamp", ts.to_string())
.text(BODY)
.await
.assert_status(axum::http::StatusCode::ACCEPTED);
// Outbox row landed with source_kind = 'email'.
let app_uuid = Uuid::parse_str(&app_id).unwrap();
// The dispatcher deletes the row after delivery; instead assert the
// handler fired (which proves the email row was dispatched).
let event = poll_marker(&pool, &app_id).await.expect("handler fired");
assert_eq!(event["source"], "email");
assert_eq!(event["op"], "receive");
assert_eq!(event["email"]["from"], "sender@external.com");
assert_eq!(event["email"]["to"][0], "alice@myapp.com");
assert_eq!(event["email"]["cc"][0], "bob@myapp.com");
assert_eq!(event["email"]["subject"], "Re: question");
assert_eq!(event["email"]["text"], "hello there");
assert_eq!(event["email"]["message_id"], "<abc@external.com>");
let _ = app_uuid;
}
#[tokio::test]
async fn missing_signature_is_401_when_secret_configured() {
let Some(pool) = pool_or_skip().await else {
return;
};
let (server, app_id) = server_for(pool, "nosig").await;
let handler = create_script(&server, &app_id, "h", MARKER_HANDLER).await;
let trigger = create_email_trigger(&server, &app_id, &handler, Some("topsecret")).await;
server
.post(&format!("/api/v1/email-inbound/{app_id}/{trigger}"))
.text(BODY)
.await
.assert_status(axum::http::StatusCode::UNAUTHORIZED);
}
#[tokio::test]
async fn wrong_signature_is_401() {
let Some(pool) = pool_or_skip().await else {
return;
};
let (server, app_id) = server_for(pool, "wrongsig").await;
let handler = create_script(&server, &app_id, "h", MARKER_HANDLER).await;
let trigger = create_email_trigger(&server, &app_id, &handler, Some("topsecret")).await;
let ts = now_ts();
server
.post(&format!("/api/v1/email-inbound/{app_id}/{trigger}"))
.add_header("x-picloud-signature", sign("WRONG", ts, BODY))
.add_header("x-picloud-timestamp", ts.to_string())
.text(BODY)
.await
.assert_status(axum::http::StatusCode::UNAUTHORIZED);
}
#[tokio::test]
async fn create_without_inbound_secret_is_rejected() {
// Audit 2026-06-11 H-B2 — email triggers must be created with an
// HMAC secret. The previous behavior accepted None and silently
// turned off signature verification at runtime.
let Some(pool) = pool_or_skip().await else {
return;
};
let (server, app_id) = server_for(pool, "no-secret").await;
let handler = create_script(&server, &app_id, "h", MARKER_HANDLER).await;
let resp = server
.post(&format!("/api/v1/admin/apps/{app_id}/triggers/email"))
.json(&json!({ "script_id": handler, "inbound_secret": null }))
.await;
resp.assert_status(axum::http::StatusCode::BAD_REQUEST);
let resp = server
.post(&format!("/api/v1/admin/apps/{app_id}/triggers/email"))
.json(&json!({ "script_id": handler, "inbound_secret": "" }))
.await;
resp.assert_status(axum::http::StatusCode::BAD_REQUEST);
let resp = server
.post(&format!("/api/v1/admin/apps/{app_id}/triggers/email"))
.json(&json!({ "script_id": handler, "inbound_secret": " " }))
.await;
resp.assert_status(axum::http::StatusCode::BAD_REQUEST);
}
#[tokio::test]
async fn unknown_trigger_is_404() {
let Some(pool) = pool_or_skip().await else {
return;
};
let (server, app_id) = server_for(pool, "missing").await;
let missing = Uuid::new_v4();
server
.post(&format!("/api/v1/email-inbound/{app_id}/{missing}"))
.text(BODY)
.await
.assert_status(axum::http::StatusCode::NOT_FOUND);
}
#[tokio::test]
async fn wrong_kind_trigger_is_404() {
let Some(pool) = pool_or_skip().await else {
return;
};
let (server, app_id) = server_for(pool, "wrongkind").await;
let handler = create_script(&server, &app_id, "h", MARKER_HANDLER).await;
// A KV trigger — not an email trigger.
let kv_trigger: Value = server
.post(&format!("/api/v1/admin/apps/{app_id}/triggers/kv"))
.json(&json!({ "script_id": handler, "collection_glob": "*" }))
.await
.json();
let kv_id = kv_trigger["id"].as_str().unwrap();
server
.post(&format!("/api/v1/email-inbound/{app_id}/{kv_id}"))
.text(BODY)
.await
.assert_status(axum::http::StatusCode::NOT_FOUND);
}
#[tokio::test]
async fn malformed_body_is_422() {
let Some(pool) = pool_or_skip().await else {
return;
};
let (server, app_id) = server_for(pool, "malformed").await;
let handler = create_script(&server, &app_id, "h", MARKER_HANDLER).await;
let trigger = create_email_trigger(&server, &app_id, &handler, Some("topsecret")).await;
// Sign the malformed body so we reach the parse step (audit
// 2026-06-11 H-B2 — HMAC is now mandatory).
let bad_body = "not json at all";
let ts = now_ts();
let sig = sign("topsecret", ts, bad_body);
server
.post(&format!("/api/v1/email-inbound/{app_id}/{trigger}"))
.add_header("x-picloud-signature", sig)
.add_header("x-picloud-timestamp", ts.to_string())
.text(bad_body)
.await
.assert_status(axum::http::StatusCode::UNPROCESSABLE_ENTITY);
}
#[tokio::test]
async fn cross_app_path_is_404() {
let Some(pool) = pool_or_skip().await else {
return;
};
// Two apps under the same server. A trigger created in app B must
// not be reachable via app A's path segment.
let (server, app_a) = server_for(pool.clone(), "xa").await;
let app_b: Value = server
.post("/api/v1/admin/apps")
.json(&json!({ "slug": format!("xb-{}", Uuid::new_v4().simple()), "name": "xb" }))
.await
.json();
let app_b_id = app_b["id"].as_str().unwrap().to_string();
let handler_b = create_script(&server, &app_b_id, "hb", MARKER_HANDLER).await;
// Audit 2026-06-11 H-B2 — secret required on create; the path-
// app-id mismatch fires before HMAC verification anyway.
let trigger_b = create_email_trigger(&server, &app_b_id, &handler_b, Some("s")).await;
// POST to app A's path with app B's trigger id → 404 (path-bound).
server
.post(&format!("/api/v1/email-inbound/{app_a}/{trigger_b}"))
.text(BODY)
.await
.assert_status(axum::http::StatusCode::NOT_FOUND);
}