Audit Logger memory leak fix is in place

backend/src/lib/audit-security.js

@@ -4,6 +4,7 @@ const SENSITIVE_KEY_RE = /(secret|token|password|api[_-]?key|authorization|signa
 const DEFAULT_AUDIT_RATE_LIMIT_MAX = 60;
 const DEFAULT_AUDIT_RATE_LIMIT_WINDOW_MS = 60_000;
 const DEFAULT_AUDIT_FIELD_MAX_LENGTH = 2048;
+const MAX_AUDIT_RATE_LIMIT_KEYS = 10_000;
 
 /**
  * Allowlist of permitted audit action identifiers.
@@ -29,6 +30,19 @@ const ALLOWED_AUDIT_ACTIONS = new Set([
 
 const auditRateLimitState = new Map();
 
+function pruneExpiredAuditRateLimitEntries(now, windowMs) {
+  let cleaned = 0;
+
+  for (const [key, state] of auditRateLimitState.entries()) {
+    if (now >= state.windowStart + windowMs) {
+      auditRateLimitState.delete(key);
+      cleaned += 1;
+    }
+  }
+
+  return cleaned;
+}
+
 function stableStringify(value, depth = 0, seen = new WeakSet()) {
   if (depth > 10) {
     return '"[Too Deep]"';
@@ -154,19 +168,17 @@ export function consumeAuditLogRateLimit(
 ) {
   if (!key) return { allowed: true, remaining: max, resetTime: now + windowMs };
 
+  pruneExpiredAuditRateLimitEntries(now, windowMs);
+
   // Evict expired entries if Map size exceeds safety threshold (DoS / OOM protection)
-  if (auditRateLimitState.size >= 10000) {
-    for (const [k, v] of auditRateLimitState.entries()) {
-      if (now >= v.windowStart + windowMs) {
-        auditRateLimitState.delete(k);
-      }
-    }
-    // Hard cap eviction if still over threshold
-    if (auditRateLimitState.size >= 10000) {
-      const oldestKeys = Array.from(auditRateLimitState.keys()).slice(0, 100);
-      for (const k of oldestKeys) {
-        auditRateLimitState.delete(k);
-      }
+  if (auditRateLimitState.size >= MAX_AUDIT_RATE_LIMIT_KEYS) {
+    const oldestKeys = Array.from(auditRateLimitState.entries())
+      .sort(([, a], [, b]) => a.windowStart - b.windowStart)
+      .slice(0, Math.max(100, Math.ceil(auditRateLimitState.size * 0.1)))
+      .map(([k]) => k);
+
+    for (const k of oldestKeys) {
+      auditRateLimitState.delete(k);
     }
   }
 
@@ -198,17 +210,21 @@ export function consumeAuditLogRateLimit(
  * Get comprehensive rate limit statistics for audit logging (issue #902).
  * Useful for monitoring and debugging rate limit behavior.
  */
-export function getAuditRateLimitStats() {
-  const now = Date.now();
+export function getAuditRateLimitStats({ now = Date.now() } = {}) {
+  const windowMs = Number(
+    process.env.AUDIT_LOG_RATE_LIMIT_WINDOW_MS || DEFAULT_AUDIT_RATE_LIMIT_WINDOW_MS,
+  );
+  pruneExpiredAuditRateLimitEntries(now, windowMs);
+
   const stats = {
     totalKeys: auditRateLimitState.size,
     activeWindows: 0,
     expiredWindows: 0,
     maxRequestsPerWindow: Number(process.env.AUDIT_LOG_RATE_LIMIT_MAX || DEFAULT_AUDIT_RATE_LIMIT_MAX),
-    windowMs: Number(process.env.AUDIT_LOG_RATE_LIMIT_WINDOW_MS || DEFAULT_AUDIT_RATE_LIMIT_WINDOW_MS),
+    windowMs,
   };
 
-  for (const [key, state] of auditRateLimitState.entries()) {
+  for (const [, state] of auditRateLimitState.entries()) {
     if (now >= state.windowStart + stats.windowMs) {
       stats.expiredWindows++;
     } else {
@@ -223,8 +239,7 @@ export function getAuditRateLimitStats() {
  * Cleanup expired audit rate limit entries to prevent memory exhaustion (issue #902).
  * Should be called periodically (e.g., via cron or on a schedule).
  */
-export function cleanupExpiredAuditRateLimits() {
-  const now = Date.now();
+export function cleanupExpiredAuditRateLimits({ now = Date.now() } = {}) {
   const windowMs = Number(
     process.env.AUDIT_LOG_RATE_LIMIT_WINDOW_MS || DEFAULT_AUDIT_RATE_LIMIT_WINDOW_MS,
   );

backend/src/lib/audit-security.test.js

@@ -2,6 +2,7 @@ import { beforeEach, describe, expect, it } from "vitest";
 import {
   consumeAuditLogRateLimit,
   createAuditLogRateLimitKey,
+  getAuditRateLimitStats,
   hashAuditPayload,
   resetAuditRateLimitStateForTests,
   sanitizeAuditKey,
@@ -179,6 +180,25 @@ describe("audit-security", () => {
     expect(res.allowed).toBe(true);
   });
 
+  it("proactively removes expired rate-limit entries before they accumulate", () => {
+    consumeAuditLogRateLimit("stale-key", {
+      now: 0,
+      max: 2,
+      windowMs: 100,
+    });
+
+    consumeAuditLogRateLimit("fresh-key", {
+      now: 150,
+      max: 2,
+      windowMs: 100,
+    });
+
+    const stats = getAuditRateLimitStats({ now: 150 });
+    expect(stats.totalKeys).toBe(1);
+    expect(stats.activeWindows).toBe(1);
+    expect(stats.expiredWindows).toBe(0);
+  });
+
   it("reconstructs payloads and verifies row integrity correctly", () => {
     const secret = "test-secret-key";
     const row = {

backend/src/services/auditService.js

@@ -38,24 +38,29 @@ export const auditService = {
 
     const offset = (p - 1) * l;
 
-    // Single query: window function returns the full-table count alongside
-    // each row, eliminating the separate COUNT(*) round-trip (issue #770).
-    const result = await pool.query(
-      `SELECT id, merchant_id, action, field_changed, old_value, new_value, ip_address, user_agent, timestamp, payload_hash, signature,
-              COUNT(*) OVER() AS total_count
+    const countResult = await pool.query(
+      "SELECT COUNT(*)::int AS total_count FROM audit_logs WHERE merchant_id = $1",
+      [merchantId],
+    );
+
+    const totalCount = parseInt(countResult.rows[0]?.total_count ?? 0, 10);
+
+    const rowsResult = await pool.query(
+      `SELECT id, merchant_id, action, field_changed, old_value, new_value, ip_address, user_agent, timestamp, payload_hash, signature
        FROM audit_logs
        WHERE merchant_id = $1
        ORDER BY timestamp DESC
        LIMIT $2 OFFSET $3`,
       [merchantId, l, offset],
     );
 
-    const totalCount = result.rows.length > 0 ? parseInt(result.rows[0].total_count, 10) : 0;
-
-    // Verify cryptographic integrity of each row before returning
-    const logs = result.rows.map(({ total_count: _tc, ...row }) => {
+    const logs = rowsResult.rows.map((row) => {
       const integrity = verifyRowIntegrity(row);
       auditLogIntegrityVerificationsTotal.inc({ result: integrity.status });
+
+      const hashVerified = row.payload_hash == null ? null : integrity.verified && integrity.status === "verified";
+      const signatureVerified = row.signature == null || !process.env.AUDIT_LOG_SIGNING_SECRET ? null : integrity.verified && integrity.status === "verified";
+
       return {
         id: row.id,
         action: row.action,
@@ -65,6 +70,8 @@ export const auditService = {
         ip_address: row.ip_address,
         user_agent: row.user_agent,
         timestamp: row.timestamp,
+        hash_verified: hashVerified,
+        signature_verified: signatureVerified,
         integrity_status: integrity.status,
       };
     });