feat(mcp): persist login audit for OAuth and API key

- Add audit::log_login in secrets-core (audit_log detail: user_id, provider, client_ip, user_agent)
- Log web Google OAuth success after session established
- Log MCP Bearer API key auth success in middleware
- Bump secrets-mcp to 0.1.6 (tag 0.1.5 existed)

Made-with: Cursor

crates/secrets-core/src/audit.rs

@@ -1,11 +1,60 @@
-use serde_json::Value;
-use sqlx::{Postgres, Transaction};
+use serde_json::{Value, json};
+use sqlx::{PgPool, Postgres, Transaction};
+use uuid::Uuid;
+
+pub const ACTION_LOGIN: &str = "login";
+pub const NAMESPACE_AUTH: &str = "auth";
 
 /// Return the current OS user as the audit actor (falls back to empty string).
 pub fn current_actor() -> String {
     std::env::var("USER").unwrap_or_default()
 }
 
+fn login_detail(
+    user_id: Uuid,
+    provider: &str,
+    client_ip: Option<&str>,
+    user_agent: Option<&str>,
+) -> Value {
+    json!({
+        "user_id": user_id,
+        "provider": provider,
+        "client_ip": client_ip,
+        "user_agent": user_agent,
+    })
+}
+
+/// Write a login audit entry without requiring an explicit transaction.
+pub async fn log_login(
+    pool: &PgPool,
+    kind: &str,
+    provider: &str,
+    user_id: Uuid,
+    client_ip: Option<&str>,
+    user_agent: Option<&str>,
+) {
+    let actor = current_actor();
+    let detail = login_detail(user_id, provider, client_ip, user_agent);
+    let result: Result<_, sqlx::Error> = sqlx::query(
+        "INSERT INTO audit_log (action, namespace, kind, name, detail, actor) \
+         VALUES ($1, $2, $3, $4, $5, $6)",
+    )
+    .bind(ACTION_LOGIN)
+    .bind(NAMESPACE_AUTH)
+    .bind(kind)
+    .bind(provider)
+    .bind(&detail)
+    .bind(&actor)
+    .execute(pool)
+    .await;
+
+    if let Err(e) = result {
+        tracing::warn!(error = %e, kind, provider, "failed to write login audit log");
+    } else {
+        tracing::debug!(kind, provider, ?user_id, actor, "login audit logged");
+    }
+}
+
 /// Write an audit entry within an existing transaction.
 pub async fn log_tx(
     tx: &mut Transaction<'_, Postgres>,
@@ -35,3 +84,19 @@ pub async fn log_tx(
         tracing::debug!(action, namespace, kind, name, actor, "audit logged");
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn login_detail_includes_expected_fields() {
+        let user_id = Uuid::nil();
+        let detail = login_detail(user_id, "google", Some("127.0.0.1"), Some("Mozilla/5.0"));
+
+        assert_eq!(detail["user_id"], json!(user_id));
+        assert_eq!(detail["provider"], "google");
+        assert_eq!(detail["client_ip"], "127.0.0.1");
+        assert_eq!(detail["user_agent"], "Mozilla/5.0");
+    }
+}

crates/secrets-mcp/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "secrets-mcp"
-version = "0.1.5"
+version = "0.1.6"
 edition.workspace = true
 
 [[bin]]

crates/secrets-mcp/src/auth.rs

@@ -9,6 +9,7 @@ use axum::{
 use sqlx::PgPool;
 use uuid::Uuid;
 
+use secrets_core::audit::log_login;
 use secrets_core::service::api_key::validate_api_key;
 
 /// Injected into request extensions after Bearer token validation.
@@ -34,6 +35,15 @@ fn log_client_ip(req: &Request) -> Option<String> {
         .map(|c| c.ip().to_string())
 }
 
+fn log_user_agent(req: &Request) -> Option<String> {
+    req.headers()
+        .get(axum::http::header::USER_AGENT)
+        .and_then(|v| v.to_str().ok())
+        .map(str::trim)
+        .filter(|value| !value.is_empty())
+        .map(ToOwned::to_owned)
+}
+
 /// Axum middleware that validates Bearer API keys for the /mcp route.
 /// Passes all non-MCP paths through without authentication.
 pub async fn bearer_auth_middleware(
@@ -44,6 +54,7 @@ pub async fn bearer_auth_middleware(
     let path = req.uri().path();
     let method = req.method().as_str();
     let client_ip = log_client_ip(&req);
+    let user_agent = log_user_agent(&req);
 
     // Only authenticate /mcp paths
     if !path.starts_with("/mcp") {
@@ -84,6 +95,15 @@ pub async fn bearer_auth_middleware(
 
     match validate_api_key(&pool, raw_key).await {
         Ok(Some(user_id)) => {
+            log_login(
+                &pool,
+                "api_key",
+                "bearer",
+                user_id,
+                client_ip.as_deref(),
+                user_agent.as_deref(),
+            )
+            .await;
             tracing::debug!(?user_id, "api key authenticated");
             let mut req = req;
             req.extensions_mut().insert(AuthUser { user_id });

crates/secrets-mcp/src/web.rs

@@ -1,9 +1,11 @@
 use askama::Template;
+use std::net::SocketAddr;
+
 use axum::{
     Json, Router,
     body::Body,
-    extract::{Path, Query, State},
-    http::{StatusCode, header},
+    extract::{ConnectInfo, Path, Query, State},
+    http::{HeaderMap, StatusCode, header},
     response::{Html, IntoResponse, Redirect, Response},
     routing::{get, post},
 };
@@ -11,6 +13,7 @@ use serde::{Deserialize, Serialize};
 use tower_sessions::Session;
 use uuid::Uuid;
 
+use secrets_core::audit::log_login;
 use secrets_core::crypto::hex;
 use secrets_core::service::{
     api_key::{ensure_api_key, regenerate_api_key},
@@ -62,6 +65,30 @@ async fn current_user_id(session: &Session) -> Option<Uuid> {
         .and_then(|s| Uuid::parse_str(&s).ok())
 }
 
+fn request_client_ip(headers: &HeaderMap, connect_info: ConnectInfo<SocketAddr>) -> Option<String> {
+    if let Some(first) = headers
+        .get("x-forwarded-for")
+        .and_then(|v| v.to_str().ok())
+        .and_then(|s| s.split(',').next())
+    {
+        let value = first.trim();
+        if !value.is_empty() {
+            return Some(value.to_string());
+        }
+    }
+
+    Some(connect_info.ip().to_string())
+}
+
+fn request_user_agent(headers: &HeaderMap) -> Option<String> {
+    headers
+        .get(header::USER_AGENT)
+        .and_then(|value| value.to_str().ok())
+        .map(str::trim)
+        .filter(|value| !value.is_empty())
+        .map(ToOwned::to_owned)
+}
+
 // ── Routes ────────────────────────────────────────────────────────────────────
 
 pub fn web_router() -> Router<AppState> {
@@ -141,16 +168,28 @@ struct OAuthCallbackQuery {
 
 async fn auth_google_callback(
     State(state): State<AppState>,
+    connect_info: ConnectInfo<SocketAddr>,
+    headers: HeaderMap,
     session: Session,
     Query(params): Query<OAuthCallbackQuery>,
 ) -> Result<Response, StatusCode> {
-    handle_oauth_callback(&state, &session, params, "google", |s, cfg, code| {
-        Box::pin(crate::oauth::google::exchange_code(
-            &s.http_client,
-            cfg,
-            code,
-        ))
-    })
+    let client_ip = request_client_ip(&headers, connect_info);
+    let user_agent = request_user_agent(&headers);
+    handle_oauth_callback(
+        &state,
+        &session,
+        params,
+        "google",
+        client_ip.as_deref(),
+        user_agent.as_deref(),
+        |s, cfg, code| {
+            Box::pin(crate::oauth::google::exchange_code(
+                &s.http_client,
+                cfg,
+                code,
+            ))
+        },
+    )
     .await
 }
 
@@ -161,6 +200,8 @@ async fn handle_oauth_callback<F>(
     session: &Session,
     params: OAuthCallbackQuery,
     provider: &str,
+    client_ip: Option<&str>,
+    user_agent: Option<&str>,
     exchange_fn: F,
 ) -> Result<Response, StatusCode>
 where
@@ -274,6 +315,16 @@ where
         .await
         .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
 
+    log_login(
+        &state.pool,
+        "oauth",
+        provider,
+        user.id,
+        client_ip,
+        user_agent,
+    )
+    .await;
+
     Ok(Redirect::to("/dashboard").into_response())
 }
 
@@ -342,16 +393,28 @@ async fn account_bind_google(
 
 async fn account_bind_google_callback(
     State(state): State<AppState>,
+    connect_info: ConnectInfo<SocketAddr>,
+    headers: HeaderMap,
     session: Session,
     Query(params): Query<OAuthCallbackQuery>,
 ) -> Result<Response, StatusCode> {
-    handle_oauth_callback(&state, &session, params, "google", |s, cfg, code| {
-        Box::pin(crate::oauth::google::exchange_code(
-            &s.http_client,
-            cfg,
-            code,
-        ))
-    })
+    let client_ip = request_client_ip(&headers, connect_info);
+    let user_agent = request_user_agent(&headers);
+    handle_oauth_callback(
+        &state,
+        &session,
+        params,
+        "google",
+        client_ip.as_deref(),
+        user_agent.as_deref(),
+        |s, cfg, code| {
+            Box::pin(crate::oauth::google::exchange_code(
+                &s.http_client,
+                cfg,
+                code,
+            ))
+        },
+    )
     .await
 }