feat: add audit log system with hash chain integrity

- Complete audit logging for INSERT, UPDATE, DELETE operations
- SHA-256 hash chain for tamper detection
- File rotation by size (100MB) and age (30 days)
- Context tracking (user, app, host, pid)
- JSON Lines format output
- verifyChain() for integrity verification
- Comprehensive REFERENCE.md technical documentation

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
This commit is contained in:
reugenio 2025-12-08 22:56:23 +01:00
parent 427628116b
commit 6891d6e026
10 changed files with 4596 additions and 0 deletions

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# Audit Log System - Diseño de Arquitectura
## Visión General
Sistema de log histórico externo para zsqlite que permite:
1. **v1.0**: Auditoría completa de operaciones con integridad verificable
2. **v2.0**: Navegación temporal (time travel) a cualquier punto en el historial
## Arquitectura
```
┌─────────────────────────────────────────────────────────────────────┐
│ Aplicación │
│ ┌─────────────┐ │
│ │ AuditCtx │ ◀── user_id, app_name (proporcionado por app) │
│ └─────────────┘ │
└────────┬────────────────────────────────────────────────────────────┘
┌─────────────────────────────────────────────────────────────────────┐
│ AuditLog │
│ ┌──────────────────────────────────────────────────────────────┐ │
│ │ Hooks: pre-update, update, commit, rollback │ │
│ │ Captura: SQL + valores antes/después + metadatos │ │
│ └──────────────────────────────────────────────────────────────┘ │
│ │ │
│ ▼ │
│ ┌──────────────────────────────────────────────────────────────┐ │
│ │ Entry Buffer (en memoria hasta commit) │ │
│ │ - Agrupa operaciones por transacción │ │
│ │ - Descarta si rollback │ │
│ └──────────────────────────────────────────────────────────────┘ │
│ │ │
│ ▼ │
│ ┌──────────────────────────────────────────────────────────────┐ │
│ │ LogWriter │ │
│ │ - Escribe a archivo │ │
│ │ - Gestiona rotación │ │
│ │ - Calcula hash chain │ │
│ └──────────────────────────────────────────────────────────────┘ │
└────────┬────────────────────────────────────────────────────────────┘
┌─────────────────────────────────────────────────────────────────────┐
│ Sistema de Archivos │
│ │
│ mydb_audit_0001.log ──▶ mydb_audit_0002.log ──▶ ... │
│ (hash chain) (hash chain) │
│ │
│ mydb_audit_index.json ◀── Índice de archivos y rangos de tiempo │
└─────────────────────────────────────────────────────────────────────┘
```
---
## Formato de Entrada de Log
Cada operación se registra en formato JSON Lines (una línea por entrada):
```json
{
"seq": 1,
"ts": "2025-12-08T14:32:15.123456Z",
"tx_id": 42,
"ctx": {
"user": "alice",
"app": "simifactu",
"host": "workstation-01",
"pid": 12345
},
"op": "UPDATE",
"table": "invoices",
"rowid": 157,
"sql": "UPDATE invoices SET status = 'paid' WHERE id = 157",
"before": {
"id": 157,
"status": "pending",
"amount": 1500.00
},
"after": {
"id": 157,
"status": "paid",
"amount": 1500.00
},
"prev_hash": "a1b2c3d4e5f6...",
"hash": "f6e5d4c3b2a1..."
}
```
### Campos
| Campo | Tipo | Descripción |
|-------|------|-------------|
| `seq` | u64 | Número de secuencia global (nunca se repite) |
| `ts` | ISO8601 | Timestamp con microsegundos |
| `tx_id` | u64 | ID de transacción (agrupa operaciones) |
| `ctx` | object | Contexto: user, app, host, pid |
| `op` | string | INSERT, UPDATE, DELETE |
| `table` | string | Nombre de la tabla |
| `rowid` | i64 | SQLite rowid |
| `sql` | string | SQL ejecutado (si está disponible) |
| `before` | object? | Valores antes (NULL para INSERT) |
| `after` | object? | Valores después (NULL para DELETE) |
| `prev_hash` | string | Hash de la entrada anterior |
| `hash` | string | SHA-256 de esta entrada (sin el campo hash) |
---
## Estructura de Archivos
```
mydb_audit/
├── index.json # Índice maestro
├── 0001_20251208_143200.log # Archivo de log
├── 0002_20251209_000000.log # Siguiente archivo
└── ...
```
### index.json
```json
{
"version": 1,
"db_name": "mydb.sqlite",
"created": "2025-12-08T14:32:00Z",
"files": [
{
"id": 1,
"filename": "0001_20251208_143200.log",
"seq_start": 1,
"seq_end": 15420,
"ts_start": "2025-12-08T14:32:00Z",
"ts_end": "2025-12-08T23:59:59Z",
"entries": 15420,
"bytes": 8523410,
"first_hash": "000000...",
"last_hash": "a1b2c3...",
"closed": true
},
{
"id": 2,
"filename": "0002_20251209_000000.log",
"seq_start": 15421,
"seq_end": null,
"ts_start": "2025-12-09T00:00:00Z",
"ts_end": null,
"entries": 342,
"bytes": 182340,
"first_hash": "a1b2c3...",
"last_hash": "d4e5f6...",
"closed": false
}
],
"rotation": {
"max_bytes": 104857600,
"max_age_days": 30
}
}
```
---
## Rotación de Archivos
Criterios (configurable, se aplica el primero que se cumpla):
1. **Por tamaño**: cuando alcanza `max_bytes` (default: 100MB)
2. **Por tiempo**: cuando pasa `max_age_days` (default: 30 días)
3. **Manual**: API para forzar rotación
Al rotar:
1. Cerrar archivo actual (marcar `closed: true`)
2. Crear nuevo archivo
3. Primer hash del nuevo = último hash del anterior (continuidad)
4. Actualizar index.json
---
## Hash Chain (Integridad)
```
Entry 1: prev_hash = "0000...0000" (genesis)
hash = SHA256(entry_1_without_hash)
Entry 2: prev_hash = hash(Entry 1)
hash = SHA256(entry_2_without_hash)
Entry N: prev_hash = hash(Entry N-1)
hash = SHA256(entry_N_without_hash)
```
### Verificación
```zig
pub fn verifyChain(log_dir: []const u8) !VerifyResult {
// 1. Leer index.json
// 2. Para cada archivo:
// - Verificar que first_hash == last_hash del anterior
// - Para cada entrada:
// - Recalcular hash
// - Verificar prev_hash == hash anterior
// 3. Reportar: OK o primera entrada corrupta
}
```
---
## API v1.0 - Auditoría
```zig
const AuditLog = @import("zsqlite").audit.AuditLog;
// Configuración
const config = AuditLog.Config{
.log_dir = "./mydb_audit",
.rotation = .{
.max_bytes = 100 * 1024 * 1024, // 100MB
.max_age_days = 30,
},
.context = .{
.app_name = "simifactu",
.user_id = null, // Se puede cambiar dinámicamente
},
.capture = .{
.sql = true,
.before_values = true,
.after_values = true,
},
};
// Inicializar
var audit = try AuditLog.init(allocator, &db, config);
defer audit.deinit();
// Cambiar usuario dinámicamente (ej: después de login)
audit.setUser("alice");
// El audit log captura automáticamente via hooks
try db.exec("INSERT INTO users (name) VALUES ('Bob')");
// Forzar rotación manual
try audit.rotate();
// Verificar integridad
const result = try audit.verify();
if (!result.valid) {
std.debug.print("Corrupto en seq {}\n", .{result.first_invalid_seq});
}
// Estadísticas
const stats = audit.stats();
std.debug.print("Entries: {}, Files: {}\n", .{stats.total_entries, stats.file_count});
```
---
## API v2.0 - Time Travel
```zig
const TimeMachine = @import("zsqlite").audit.TimeMachine;
// Inicializar con log existente
var tm = try TimeMachine.init(allocator, "./mydb_audit");
defer tm.deinit();
// Obtener estado en un momento específico
var snapshot_db = try tm.getStateAt("2025-12-08T15:30:00Z");
defer snapshot_db.close();
// snapshot_db es una DB en memoria con el estado de ese momento
// O navegar por secuencia
var snapshot_db2 = try tm.getStateAtSeq(1000);
// Replay: reconstruir DB desde cero
var rebuilt_db = try tm.replay(":memory:");
defer rebuilt_db.close();
// Replay parcial: desde snapshot hasta punto
var partial_db = try tm.replayRange(
"base_snapshot.sqlite", // Punto de partida
5000, // seq_start
8000, // seq_end
);
// Undo: revertir últimas N operaciones
try tm.undoLast(&db, 5);
// Redo: re-aplicar operaciones revertidas
try tm.redo(&db, 3);
// Ver historial de una fila específica
const history = try tm.getRowHistory("invoices", 157);
defer allocator.free(history);
for (history) |entry| {
std.debug.print("{s}: {s} -> {s}\n", .{entry.ts, entry.op, entry.after});
}
```
---
## Consideraciones de Rendimiento
### v1.0
- **Overhead mínimo**: hooks son muy ligeros
- **Buffering**: acumular en memoria hasta commit
- **Async write**: opción de escribir en thread separado
- **Compresión**: opcional, gzip por archivo cerrado
### v2.0
- **Snapshots periódicos**: cada N operaciones o tiempo
- Reduce tiempo de replay
- `snapshot_0001.sqlite` + logs desde ahí
- **Índices en memoria**: para búsqueda rápida por tiempo/tabla/rowid
- **Lazy loading**: cargar solo los logs necesarios
---
## Flujo de Datos
### Captura (v1.0)
```
1. App ejecuta SQL
2. Pre-update hook captura valores ANTES
3. SQLite ejecuta la operación
4. Update hook captura operación + rowid
5. Guardar en buffer de transacción
├── Commit hook ──▶ Escribir buffer a archivo
└── Rollback hook ──▶ Descartar buffer
```
### Replay (v2.0)
```
1. Encontrar snapshot más cercano anterior al tiempo deseado
2. Cargar snapshot a memoria
3. Leer logs desde snapshot hasta tiempo deseado
4. Para cada entrada:
- INSERT: ejecutar INSERT con valores `after`
- UPDATE: ejecutar UPDATE con valores `after`
- DELETE: ejecutar DELETE
5. Retornar DB en estado deseado
```
### Undo
```
1. Leer entrada a revertir
2. Según operación:
- INSERT: DELETE WHERE rowid = X
- UPDATE: UPDATE SET (valores `before`) WHERE rowid = X
- DELETE: INSERT con valores `before`
3. Registrar operación de undo en el log (para auditoría)
```
---
## Seguridad (Futuro)
- **Encriptación**: AES-256-GCM por archivo
- **Firma digital**: además de hash, firmar con clave privada
- **Acceso**: permisos de lectura separados de escritura
---
## Módulos a Implementar
```
src/
├── audit/
│ ├── mod.zig # Exports
│ ├── log.zig # AuditLog principal
│ ├── writer.zig # Escritura a archivo
│ ├── entry.zig # Estructura de entrada
│ ├── context.zig # Contexto (user, app, host)
│ ├── rotation.zig # Gestión de rotación
│ ├── index.zig # Índice de archivos
│ ├── hash.zig # Hash chain
│ ├── verify.zig # Verificación de integridad
│ └── time_machine.zig # Time travel (v2.0)
```
---
## Fases de Implementación
### Fase 1: Core (v1.0)
1. Estructura de entrada y serialización JSON
2. Writer con rotación básica
3. Hash chain
4. Hooks para captura
5. Contexto y metadatos
### Fase 2: Integridad (v1.0)
1. Verificación de cadena
2. Index.json completo
3. Estadísticas
### Fase 3: Time Travel (v2.0)
1. Replay hacia adelante
2. Undo/Redo
3. getStateAt()
4. getRowHistory()
### Fase 4: Optimización (v2.0)
1. Snapshots automáticos
2. Índices en memoria
3. Compresión de archivos cerrados
---
## Preguntas Resueltas
| Pregunta | Decisión |
|----------|----------|
| ¿Qué capturar? | SQL + valores antes/después |
| ¿Cómo identificar contexto? | Mixto: auto-detectar host/pid, app proporciona user/app_name |
| ¿Cuándo rotar? | Configurable: por defecto 100MB o 30 días |
| ¿Granularidad time travel? | Cualquier operación (seq exacto) |

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//! Audit Context
//!
//! Manages contextual information (user, app, host, pid) for audit entries.
//! Supports both auto-detected and application-provided values.
const std = @import("std");
const builtin = @import("builtin");
const Allocator = std.mem.Allocator;
/// Audit context that tracks who/what is performing operations
pub const AuditContext = struct {
allocator: Allocator,
/// User identifier (provided by application)
user: ?[]const u8 = null,
/// Application name (provided by application)
app: ?[]const u8 = null,
/// Hostname (auto-detected or provided)
host: ?[]const u8 = null,
/// Process ID (auto-detected)
pid: ?u32 = null,
const Self = @This();
/// Initialize with auto-detected values
pub fn init(allocator: Allocator) Self {
return Self{
.allocator = allocator,
.pid = getPid(),
.host = null, // Detected lazily on first toEntryContext call
};
}
/// Initialize with application-provided values
pub fn initWithApp(allocator: Allocator, app_name: []const u8) !Self {
return Self{
.allocator = allocator,
.app = try allocator.dupe(u8, app_name),
.pid = getPid(),
.host = null,
};
}
pub fn deinit(self: *Self) void {
if (self.user) |u| self.allocator.free(u);
if (self.app) |a| self.allocator.free(a);
if (self.host) |h| self.allocator.free(h);
self.* = undefined;
}
/// Set the current user (e.g., after login)
pub fn setUser(self: *Self, user: ?[]const u8) !void {
if (self.user) |u| self.allocator.free(u);
self.user = if (user) |u| try self.allocator.dupe(u8, u) else null;
}
/// Set the application name
pub fn setApp(self: *Self, app: ?[]const u8) !void {
if (self.app) |a| self.allocator.free(a);
self.app = if (app) |a| try self.allocator.dupe(u8, a) else null;
}
/// Set the hostname (overrides auto-detection)
pub fn setHost(self: *Self, host: ?[]const u8) !void {
if (self.host) |h| self.allocator.free(h);
self.host = if (host) |h| try self.allocator.dupe(u8, h) else null;
}
/// Get context for entry (detects host if needed)
pub fn toEntryContext(self: *Self) !EntryContext {
// Detect hostname if not set
if (self.host == null) {
self.host = try detectHostname(self.allocator);
}
return EntryContext{
.user = self.user,
.app = self.app,
.host = self.host,
.pid = self.pid,
};
}
/// Clone context values for an entry (caller owns memory)
pub fn cloneForEntry(self: *Self, allocator: Allocator) !OwnedEntryContext {
// Detect hostname if not set
if (self.host == null) {
self.host = try detectHostname(self.allocator);
}
return OwnedEntryContext{
.user = if (self.user) |u| try allocator.dupe(u8, u) else null,
.app = if (self.app) |a| try allocator.dupe(u8, a) else null,
.host = if (self.host) |h| try allocator.dupe(u8, h) else null,
.pid = self.pid,
};
}
};
/// Entry context (borrowed references)
pub const EntryContext = struct {
user: ?[]const u8,
app: ?[]const u8,
host: ?[]const u8,
pid: ?u32,
};
/// Entry context with owned memory
pub const OwnedEntryContext = struct {
user: ?[]const u8,
app: ?[]const u8,
host: ?[]const u8,
pid: ?u32,
pub fn deinit(self: *OwnedEntryContext, allocator: Allocator) void {
if (self.user) |u| allocator.free(u);
if (self.app) |a| allocator.free(a);
if (self.host) |h| allocator.free(h);
self.* = undefined;
}
};
/// Get current process ID
fn getPid() ?u32 {
if (builtin.os.tag == .linux or builtin.os.tag == .macos) {
const pid = std.os.linux.getpid();
return @intCast(pid);
}
return null;
}
/// Detect hostname from system
fn detectHostname(allocator: Allocator) !?[]const u8 {
if (builtin.os.tag == .linux or builtin.os.tag == .macos) {
var buf: [std.posix.HOST_NAME_MAX]u8 = undefined;
const hostname = std.posix.gethostname(&buf) catch return null;
return try allocator.dupe(u8, hostname);
}
return null;
}
test "AuditContext basic" {
const allocator = std.testing.allocator;
var ctx = AuditContext.init(allocator);
defer ctx.deinit();
// PID should be auto-detected
try std.testing.expect(ctx.pid != null);
// Set user and app
try ctx.setUser("alice");
try ctx.setApp("test_app");
try std.testing.expectEqualStrings("alice", ctx.user.?);
try std.testing.expectEqualStrings("test_app", ctx.app.?);
}
test "AuditContext initWithApp" {
const allocator = std.testing.allocator;
var ctx = try AuditContext.initWithApp(allocator, "my_app");
defer ctx.deinit();
try std.testing.expectEqualStrings("my_app", ctx.app.?);
try std.testing.expect(ctx.user == null);
}
test "AuditContext toEntryContext" {
const allocator = std.testing.allocator;
var ctx = AuditContext.init(allocator);
defer ctx.deinit();
try ctx.setUser("bob");
try ctx.setApp("app");
const entry_ctx = try ctx.toEntryContext();
try std.testing.expectEqualStrings("bob", entry_ctx.user.?);
try std.testing.expectEqualStrings("app", entry_ctx.app.?);
// Host should be detected
try std.testing.expect(entry_ctx.host != null);
}
test "AuditContext cloneForEntry" {
const allocator = std.testing.allocator;
var ctx = AuditContext.init(allocator);
defer ctx.deinit();
try ctx.setUser("charlie");
try ctx.setApp("clone_test");
var owned = try ctx.cloneForEntry(allocator);
defer owned.deinit(allocator);
try std.testing.expectEqualStrings("charlie", owned.user.?);
try std.testing.expectEqualStrings("clone_test", owned.app.?);
// Modifying original shouldn't affect clone
try ctx.setUser("david");
try std.testing.expectEqualStrings("charlie", owned.user.?);
}

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//! Audit Log Entry
//!
//! Defines the structure and JSON serialization for audit log entries.
const std = @import("std");
const Allocator = std.mem.Allocator;
/// Operation type
pub const Operation = enum {
INSERT,
UPDATE,
DELETE,
pub fn toString(self: Operation) []const u8 {
return switch (self) {
.INSERT => "INSERT",
.UPDATE => "UPDATE",
.DELETE => "DELETE",
};
}
pub fn fromString(s: []const u8) ?Operation {
if (std.mem.eql(u8, s, "INSERT")) return .INSERT;
if (std.mem.eql(u8, s, "UPDATE")) return .UPDATE;
if (std.mem.eql(u8, s, "DELETE")) return .DELETE;
return null;
}
};
/// Context information for an audit entry
pub const Context = struct {
user: ?[]const u8 = null,
app: ?[]const u8 = null,
host: ?[]const u8 = null,
pid: ?u32 = null,
pub fn deinit(self: *Context, allocator: Allocator) void {
if (self.user) |u| allocator.free(u);
if (self.app) |a| allocator.free(a);
if (self.host) |h| allocator.free(h);
self.* = .{};
}
pub fn clone(self: *const Context, allocator: Allocator) !Context {
return Context{
.user = if (self.user) |u| try allocator.dupe(u8, u) else null,
.app = if (self.app) |a| try allocator.dupe(u8, a) else null,
.host = if (self.host) |h| try allocator.dupe(u8, h) else null,
.pid = self.pid,
};
}
};
/// A single audit log entry
pub const Entry = struct {
/// Sequence number (global, never repeats)
seq: u64,
/// Timestamp in microseconds since epoch
timestamp_us: i64,
/// Transaction ID (groups operations)
tx_id: u64,
/// Context (user, app, host, pid)
ctx: Context,
/// Operation type
op: Operation,
/// Table name
table: []const u8,
/// SQLite rowid
rowid: i64,
/// SQL statement (if available)
sql: ?[]const u8,
/// Values before operation (null for INSERT)
before: ?[]const u8,
/// Values after operation (null for DELETE)
after: ?[]const u8,
/// Hash of previous entry
prev_hash: [64]u8,
/// Hash of this entry
hash: [64]u8,
const Self = @This();
pub fn deinit(self: *Self, allocator: Allocator) void {
self.ctx.deinit(allocator);
allocator.free(self.table);
if (self.sql) |s| allocator.free(s);
if (self.before) |b| allocator.free(b);
if (self.after) |a| allocator.free(a);
self.* = undefined;
}
/// Format timestamp as ISO8601 with microseconds
pub fn formatTimestamp(self: *const Self, buf: *[30]u8) []const u8 {
const secs: u64 = @intCast(@divFloor(self.timestamp_us, 1_000_000));
const us: u64 = @intCast(@mod(self.timestamp_us, 1_000_000));
const epoch_secs: i64 = @intCast(secs);
const es = std.time.epoch.EpochSeconds{ .secs = @intCast(epoch_secs) };
const day_seconds = es.getDaySeconds();
const year_day = es.getEpochDay().calculateYearDay();
const hours = day_seconds.getHoursIntoDay();
const minutes = day_seconds.getMinutesIntoHour();
const seconds_val = day_seconds.getSecondsIntoMinute();
const month_day = year_day.calculateMonthDay();
const year = year_day.year;
const month = month_day.month.numeric();
const day = month_day.day_index + 1;
const len = std.fmt.bufPrint(buf, "{d:0>4}-{d:0>2}-{d:0>2}T{d:0>2}:{d:0>2}:{d:0>2}.{d:0>6}Z", .{
year, month, day, hours, minutes, seconds_val, us,
}) catch return "";
return buf[0..len.len];
}
/// Serialize entry to JSON (without trailing newline)
pub fn toJson(self: *const Self, allocator: Allocator) ![]u8 {
var list: std.ArrayListUnmanaged(u8) = .empty;
errdefer list.deinit(allocator);
const writer = list.writer(allocator);
// Format timestamp
var ts_buf: [30]u8 = undefined;
const ts_str = self.formatTimestamp(&ts_buf);
try writer.writeAll("{");
// seq
try writer.print("\"seq\":{d},", .{self.seq});
// ts
try writer.print("\"ts\":\"{s}\",", .{ts_str});
// tx_id
try writer.print("\"tx_id\":{d},", .{self.tx_id});
// ctx
try writer.writeAll("\"ctx\":{");
var ctx_first = true;
if (self.ctx.user) |u| {
try writer.print("\"user\":", .{});
try writeJsonString(writer, u);
ctx_first = false;
}
if (self.ctx.app) |a| {
if (!ctx_first) try writer.writeAll(",");
try writer.print("\"app\":", .{});
try writeJsonString(writer, a);
ctx_first = false;
}
if (self.ctx.host) |h| {
if (!ctx_first) try writer.writeAll(",");
try writer.print("\"host\":", .{});
try writeJsonString(writer, h);
ctx_first = false;
}
if (self.ctx.pid) |p| {
if (!ctx_first) try writer.writeAll(",");
try writer.print("\"pid\":{d}", .{p});
}
try writer.writeAll("},");
// op
try writer.print("\"op\":\"{s}\",", .{self.op.toString()});
// table
try writer.print("\"table\":", .{});
try writeJsonString(writer, self.table);
try writer.writeAll(",");
// rowid
try writer.print("\"rowid\":{d},", .{self.rowid});
// sql (optional)
if (self.sql) |s| {
try writer.print("\"sql\":", .{});
try writeJsonString(writer, s);
try writer.writeAll(",");
}
// before (optional, already JSON)
if (self.before) |b| {
try writer.print("\"before\":{s},", .{b});
}
// after (optional, already JSON)
if (self.after) |a| {
try writer.print("\"after\":{s},", .{a});
}
// prev_hash
try writer.print("\"prev_hash\":\"{s}\",", .{self.prev_hash});
// hash
try writer.print("\"hash\":\"{s}\"", .{self.hash});
try writer.writeAll("}");
return list.toOwnedSlice(allocator);
}
/// Serialize entry to JSON for hashing (without hash field)
pub fn toJsonForHash(self: *const Self, allocator: Allocator) ![]u8 {
var list: std.ArrayListUnmanaged(u8) = .empty;
errdefer list.deinit(allocator);
const writer = list.writer(allocator);
// Format timestamp
var ts_buf: [30]u8 = undefined;
const ts_str = self.formatTimestamp(&ts_buf);
try writer.writeAll("{");
// seq
try writer.print("\"seq\":{d},", .{self.seq});
// ts
try writer.print("\"ts\":\"{s}\",", .{ts_str});
// tx_id
try writer.print("\"tx_id\":{d},", .{self.tx_id});
// ctx
try writer.writeAll("\"ctx\":{");
var ctx_first = true;
if (self.ctx.user) |u| {
try writer.print("\"user\":", .{});
try writeJsonString(writer, u);
ctx_first = false;
}
if (self.ctx.app) |a| {
if (!ctx_first) try writer.writeAll(",");
try writer.print("\"app\":", .{});
try writeJsonString(writer, a);
ctx_first = false;
}
if (self.ctx.host) |h| {
if (!ctx_first) try writer.writeAll(",");
try writer.print("\"host\":", .{});
try writeJsonString(writer, h);
ctx_first = false;
}
if (self.ctx.pid) |p| {
if (!ctx_first) try writer.writeAll(",");
try writer.print("\"pid\":{d}", .{p});
}
try writer.writeAll("},");
// op
try writer.print("\"op\":\"{s}\",", .{self.op.toString()});
// table
try writer.print("\"table\":", .{});
try writeJsonString(writer, self.table);
try writer.writeAll(",");
// rowid
try writer.print("\"rowid\":{d},", .{self.rowid});
// sql (optional)
if (self.sql) |s| {
try writer.print("\"sql\":", .{});
try writeJsonString(writer, s);
try writer.writeAll(",");
}
// before (optional, already JSON)
if (self.before) |b| {
try writer.print("\"before\":{s},", .{b});
}
// after (optional, already JSON)
if (self.after) |a| {
try writer.print("\"after\":{s},", .{a});
}
// prev_hash (include in hash calculation)
try writer.print("\"prev_hash\":\"{s}\"", .{self.prev_hash});
try writer.writeAll("}");
return list.toOwnedSlice(allocator);
}
};
/// Write a JSON-escaped string
fn writeJsonString(writer: anytype, s: []const u8) !void {
try writer.writeByte('"');
for (s) |ch| {
switch (ch) {
'"' => try writer.writeAll("\\\""),
'\\' => try writer.writeAll("\\\\"),
'\n' => try writer.writeAll("\\n"),
'\r' => try writer.writeAll("\\r"),
'\t' => try writer.writeAll("\\t"),
0x00...0x08, 0x0b, 0x0c, 0x0e...0x1f => {
try writer.print("\\u{x:0>4}", .{ch});
},
else => try writer.writeByte(ch),
}
}
try writer.writeByte('"');
}
/// Builder for creating entries
pub const EntryBuilder = struct {
allocator: Allocator,
seq: u64 = 0,
timestamp_us: i64 = 0,
tx_id: u64 = 0,
ctx: Context = .{},
op: Operation = .INSERT,
table: ?[]const u8 = null,
rowid: i64 = 0,
sql: ?[]const u8 = null,
before: ?[]const u8 = null,
after: ?[]const u8 = null,
prev_hash: [64]u8 = [_]u8{'0'} ** 64,
const Self = @This();
pub fn init(allocator: Allocator) Self {
return .{ .allocator = allocator };
}
pub fn setSeq(self: *Self, seq: u64) *Self {
self.seq = seq;
return self;
}
pub fn setTimestamp(self: *Self, timestamp_us: i64) *Self {
self.timestamp_us = timestamp_us;
return self;
}
pub fn setTimestampNow(self: *Self) *Self {
self.timestamp_us = std.time.microTimestamp();
return self;
}
pub fn setTxId(self: *Self, tx_id: u64) *Self {
self.tx_id = tx_id;
return self;
}
pub fn setContext(self: *Self, ctx: Context) *Self {
self.ctx = ctx;
return self;
}
pub fn setOp(self: *Self, op: Operation) *Self {
self.op = op;
return self;
}
pub fn setTable(self: *Self, table: []const u8) !*Self {
self.table = try self.allocator.dupe(u8, table);
return self;
}
pub fn setRowid(self: *Self, rowid: i64) *Self {
self.rowid = rowid;
return self;
}
pub fn setSql(self: *Self, sql: []const u8) !*Self {
self.sql = try self.allocator.dupe(u8, sql);
return self;
}
pub fn setBefore(self: *Self, before: []const u8) !*Self {
self.before = try self.allocator.dupe(u8, before);
return self;
}
pub fn setAfter(self: *Self, after: []const u8) !*Self {
self.after = try self.allocator.dupe(u8, after);
return self;
}
pub fn setPrevHash(self: *Self, prev_hash: [64]u8) *Self {
self.prev_hash = prev_hash;
return self;
}
/// Build the entry and compute its hash
pub fn build(self: *Self) !Entry {
const table = self.table orelse return error.MissingTable;
var entry = Entry{
.seq = self.seq,
.timestamp_us = self.timestamp_us,
.tx_id = self.tx_id,
.ctx = try self.ctx.clone(self.allocator),
.op = self.op,
.table = try self.allocator.dupe(u8, table),
.rowid = self.rowid,
.sql = if (self.sql) |s| try self.allocator.dupe(u8, s) else null,
.before = if (self.before) |b| try self.allocator.dupe(u8, b) else null,
.after = if (self.after) |a| try self.allocator.dupe(u8, a) else null,
.prev_hash = self.prev_hash,
.hash = undefined,
};
// Compute hash
const json_for_hash = try entry.toJsonForHash(self.allocator);
defer self.allocator.free(json_for_hash);
var hash: [32]u8 = undefined;
std.crypto.hash.sha2.Sha256.hash(json_for_hash, &hash, .{});
// Convert to hex
entry.hash = std.fmt.bytesToHex(hash, .lower);
return entry;
}
pub fn deinit(self: *Self) void {
if (self.table) |t| self.allocator.free(t);
if (self.sql) |s| self.allocator.free(s);
if (self.before) |b| self.allocator.free(b);
if (self.after) |a| self.allocator.free(a);
self.* = undefined;
}
};
test "Entry JSON serialization" {
const allocator = std.testing.allocator;
var builder = EntryBuilder.init(allocator);
defer builder.deinit();
_ = builder.setSeq(1);
_ = builder.setTimestamp(1733667135123456); // 2024-12-08T14:32:15.123456Z approx
_ = builder.setTxId(42);
_ = builder.setContext(.{
.user = "alice",
.app = "test_app",
.host = "localhost",
.pid = 12345,
});
_ = builder.setOp(.UPDATE);
_ = try builder.setTable("users");
_ = builder.setRowid(157);
_ = try builder.setSql("UPDATE users SET name = 'Bob' WHERE id = 157");
_ = try builder.setBefore("{\"id\":157,\"name\":\"Alice\"}");
_ = try builder.setAfter("{\"id\":157,\"name\":\"Bob\"}");
var entry = try builder.build();
defer entry.deinit(allocator);
const json = try entry.toJson(allocator);
defer allocator.free(json);
// Verify it contains expected fields
try std.testing.expect(std.mem.indexOf(u8, json, "\"seq\":1") != null);
try std.testing.expect(std.mem.indexOf(u8, json, "\"op\":\"UPDATE\"") != null);
try std.testing.expect(std.mem.indexOf(u8, json, "\"table\":\"users\"") != null);
try std.testing.expect(std.mem.indexOf(u8, json, "\"user\":\"alice\"") != null);
try std.testing.expect(std.mem.indexOf(u8, json, "\"hash\":") != null);
}
test "Entry hash chain" {
const allocator = std.testing.allocator;
// Create first entry (genesis)
var builder1 = EntryBuilder.init(allocator);
_ = builder1.setSeq(1);
_ = builder1.setTimestamp(1000000);
_ = builder1.setTxId(1);
_ = builder1.setOp(.INSERT);
_ = try builder1.setTable("test");
_ = builder1.setRowid(1);
var entry1 = try builder1.build();
defer entry1.deinit(allocator);
builder1.deinit();
// Verify genesis has zeros for prev_hash
try std.testing.expectEqualStrings(&([_]u8{'0'} ** 64), &entry1.prev_hash);
// Create second entry with first's hash
var builder2 = EntryBuilder.init(allocator);
_ = builder2.setSeq(2);
_ = builder2.setTimestamp(1000001);
_ = builder2.setTxId(1);
_ = builder2.setOp(.UPDATE);
_ = try builder2.setTable("test");
_ = builder2.setRowid(1);
_ = builder2.setPrevHash(entry1.hash);
var entry2 = try builder2.build();
defer entry2.deinit(allocator);
builder2.deinit();
// Verify chain
try std.testing.expectEqualStrings(&entry1.hash, &entry2.prev_hash);
// Hashes should be different
try std.testing.expect(!std.mem.eql(u8, &entry1.hash, &entry2.hash));
}

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//! Audit Log Index
//!
//! Manages the index.json file that tracks all log files and their metadata.
const std = @import("std");
const Allocator = std.mem.Allocator;
/// Information about a single log file
pub const FileInfo = struct {
/// File ID (1-based, sequential)
id: u32,
/// Filename (e.g., "0001_20251208_143200.log")
filename: []const u8,
/// First sequence number in file
seq_start: u64,
/// Last sequence number in file (null if still open)
seq_end: ?u64,
/// First timestamp in file
ts_start: i64,
/// Last timestamp in file (null if still open)
ts_end: ?i64,
/// Number of entries in file
entries: u64,
/// File size in bytes
bytes: u64,
/// Hash of first entry
first_hash: [64]u8,
/// Hash of last entry
last_hash: [64]u8,
/// Whether file is closed (rotated)
closed: bool,
pub fn deinit(self: *FileInfo, allocator: Allocator) void {
allocator.free(self.filename);
self.* = undefined;
}
pub fn clone(self: *const FileInfo, allocator: Allocator) !FileInfo {
return FileInfo{
.id = self.id,
.filename = try allocator.dupe(u8, self.filename),
.seq_start = self.seq_start,
.seq_end = self.seq_end,
.ts_start = self.ts_start,
.ts_end = self.ts_end,
.entries = self.entries,
.bytes = self.bytes,
.first_hash = self.first_hash,
.last_hash = self.last_hash,
.closed = self.closed,
};
}
};
/// Rotation configuration
pub const RotationConfig = struct {
/// Maximum file size in bytes (default: 100MB)
max_bytes: u64 = 100 * 1024 * 1024,
/// Maximum file age in days (default: 30)
max_age_days: u32 = 30,
};
/// The audit log index
pub const Index = struct {
allocator: Allocator,
/// Index format version
version: u32 = 1,
/// Database name this audit belongs to
db_name: []const u8,
/// When the audit system was created
created: i64,
/// List of log files
files: std.ArrayListUnmanaged(FileInfo),
/// Rotation configuration
rotation: RotationConfig,
const Self = @This();
/// Create a new index
pub fn init(allocator: Allocator, db_name: []const u8) !Self {
return Self{
.allocator = allocator,
.db_name = try allocator.dupe(u8, db_name),
.created = std.time.microTimestamp(),
.files = .empty,
.rotation = .{},
};
}
/// Load index from JSON
pub fn load(allocator: Allocator, json_data: []const u8) !Self {
const parsed = try std.json.parseFromSlice(std.json.Value, allocator, json_data, .{});
defer parsed.deinit();
const root = parsed.value.object;
var index = Self{
.allocator = allocator,
.version = @intCast(root.get("version").?.integer),
.db_name = try allocator.dupe(u8, root.get("db_name").?.string),
.created = root.get("created").?.integer,
.files = .empty,
.rotation = .{},
};
// Parse rotation config
if (root.get("rotation")) |rot| {
if (rot.object.get("max_bytes")) |mb| {
index.rotation.max_bytes = @intCast(mb.integer);
}
if (rot.object.get("max_age_days")) |mad| {
index.rotation.max_age_days = @intCast(mad.integer);
}
}
// Parse files
if (root.get("files")) |files_arr| {
for (files_arr.array.items) |file_val| {
const file_obj = file_val.object;
var first_hash: [64]u8 = undefined;
var last_hash: [64]u8 = undefined;
const fh_str = file_obj.get("first_hash").?.string;
const lh_str = file_obj.get("last_hash").?.string;
@memcpy(&first_hash, fh_str[0..64]);
@memcpy(&last_hash, lh_str[0..64]);
const file_info = FileInfo{
.id = @intCast(file_obj.get("id").?.integer),
.filename = try allocator.dupe(u8, file_obj.get("filename").?.string),
.seq_start = @intCast(file_obj.get("seq_start").?.integer),
.seq_end = if (file_obj.get("seq_end")) |se| blk: {
if (se == .null) break :blk null;
break :blk @intCast(se.integer);
} else null,
.ts_start = file_obj.get("ts_start").?.integer,
.ts_end = if (file_obj.get("ts_end")) |te| blk: {
if (te == .null) break :blk null;
break :blk te.integer;
} else null,
.entries = @intCast(file_obj.get("entries").?.integer),
.bytes = @intCast(file_obj.get("bytes").?.integer),
.first_hash = first_hash,
.last_hash = last_hash,
.closed = file_obj.get("closed").?.bool,
};
try index.files.append(index.allocator, file_info);
}
}
return index;
}
pub fn deinit(self: *Self) void {
for (self.files.items) |*f| {
f.deinit(self.allocator);
}
self.files.deinit(self.allocator);
self.allocator.free(self.db_name);
self.* = undefined;
}
/// Add a new file to the index
pub fn addFile(self: *Self, info: FileInfo) !void {
try self.files.append(self.allocator, try info.clone(self.allocator));
}
/// Get the current (open) file
pub fn getCurrentFile(self: anytype) ?*FileInfo {
if (self.files.items.len == 0) return null;
const last = &self.files.items[self.files.items.len - 1];
if (!last.closed) return last;
return null;
}
/// Update the current file's metadata
pub fn updateCurrentFile(self: *Self, seq_end: u64, ts_end: i64, entries: u64, bytes: u64, last_hash: [64]u8) void {
if (self.getCurrentFile()) |file| {
file.seq_end = seq_end;
file.ts_end = ts_end;
file.entries = entries;
file.bytes = bytes;
file.last_hash = last_hash;
}
}
/// Close the current file
pub fn closeCurrentFile(self: *Self) void {
if (self.getCurrentFile()) |file| {
file.closed = true;
}
}
/// Get next file ID
pub fn getNextFileId(self: *const Self) u32 {
if (self.files.items.len == 0) return 1;
return self.files.items[self.files.items.len - 1].id + 1;
}
/// Get last hash (for chain continuity)
pub fn getLastHash(self: *const Self) [64]u8 {
if (self.files.items.len == 0) return [_]u8{'0'} ** 64;
return self.files.items[self.files.items.len - 1].last_hash;
}
/// Get last sequence number
pub fn getLastSeq(self: *const Self) u64 {
if (self.files.items.len == 0) return 0;
const last = &self.files.items[self.files.items.len - 1];
return last.seq_end orelse last.seq_start;
}
/// Find file containing a specific sequence number
pub fn findFileBySeq(self: *const Self, seq: u64) ?*const FileInfo {
for (self.files.items) |*file| {
const end = file.seq_end orelse std.math.maxInt(u64);
if (seq >= file.seq_start and seq <= end) {
return file;
}
}
return null;
}
/// Find files within a time range
pub fn findFilesByTimeRange(self: *Self, start_us: i64, end_us: i64) ![]const FileInfo {
var result: std.ArrayListUnmanaged(FileInfo) = .empty;
errdefer result.deinit(self.allocator);
for (self.files.items) |*file| {
const file_end = file.ts_end orelse std.math.maxInt(i64);
// Check overlap
if (file.ts_start <= end_us and file_end >= start_us) {
try result.append(self.allocator, try file.clone(self.allocator));
}
}
return result.toOwnedSlice(self.allocator);
}
/// Serialize to JSON
pub fn toJson(self: *const Self) ![]u8 {
var list: std.ArrayListUnmanaged(u8) = .empty;
errdefer list.deinit(self.allocator);
const writer = list.writer(self.allocator);
try writer.writeAll("{\n");
try writer.print(" \"version\": {d},\n", .{self.version});
try writer.print(" \"db_name\": \"{s}\",\n", .{self.db_name});
try writer.print(" \"created\": {d},\n", .{self.created});
// Files array
try writer.writeAll(" \"files\": [\n");
for (self.files.items, 0..) |*file, i| {
try writer.writeAll(" {\n");
try writer.print(" \"id\": {d},\n", .{file.id});
try writer.print(" \"filename\": \"{s}\",\n", .{file.filename});
try writer.print(" \"seq_start\": {d},\n", .{file.seq_start});
if (file.seq_end) |se| {
try writer.print(" \"seq_end\": {d},\n", .{se});
} else {
try writer.writeAll(" \"seq_end\": null,\n");
}
try writer.print(" \"ts_start\": {d},\n", .{file.ts_start});
if (file.ts_end) |te| {
try writer.print(" \"ts_end\": {d},\n", .{te});
} else {
try writer.writeAll(" \"ts_end\": null,\n");
}
try writer.print(" \"entries\": {d},\n", .{file.entries});
try writer.print(" \"bytes\": {d},\n", .{file.bytes});
try writer.print(" \"first_hash\": \"{s}\",\n", .{file.first_hash});
try writer.print(" \"last_hash\": \"{s}\",\n", .{file.last_hash});
try writer.print(" \"closed\": {s}\n", .{if (file.closed) "true" else "false"});
if (i < self.files.items.len - 1) {
try writer.writeAll(" },\n");
} else {
try writer.writeAll(" }\n");
}
}
try writer.writeAll(" ],\n");
// Rotation config
try writer.writeAll(" \"rotation\": {\n");
try writer.print(" \"max_bytes\": {d},\n", .{self.rotation.max_bytes});
try writer.print(" \"max_age_days\": {d}\n", .{self.rotation.max_age_days});
try writer.writeAll(" }\n");
try writer.writeAll("}\n");
return list.toOwnedSlice(self.allocator);
}
};
/// Generate filename for a new log file
pub fn generateFilename(allocator: Allocator, file_id: u32, timestamp_us: i64) ![]u8 {
const secs: u64 = @intCast(@divFloor(timestamp_us, 1_000_000));
const es = std.time.epoch.EpochSeconds{ .secs = @intCast(secs) };
const day_seconds = es.getDaySeconds();
const year_day = es.getEpochDay().calculateYearDay();
const month_day = year_day.calculateMonthDay();
const year = year_day.year;
const month = month_day.month.numeric();
const day = month_day.day_index + 1;
const hour = day_seconds.getHoursIntoDay();
const minute = day_seconds.getMinutesIntoHour();
const second = day_seconds.getSecondsIntoMinute();
return std.fmt.allocPrint(allocator, "{d:0>4}_{d:0>4}{d:0>2}{d:0>2}_{d:0>2}{d:0>2}{d:0>2}.log", .{
file_id, year, month, day, hour, minute, second,
});
}
test "Index basic operations" {
const allocator = std.testing.allocator;
var index = try Index.init(allocator, "test.db");
defer index.deinit();
try std.testing.expectEqualStrings("test.db", index.db_name);
try std.testing.expectEqual(@as(usize, 0), index.files.items.len);
try std.testing.expectEqual(@as(u32, 1), index.getNextFileId());
}
test "Index add and find file" {
const allocator = std.testing.allocator;
var index = try Index.init(allocator, "test.db");
defer index.deinit();
const file_info = FileInfo{
.id = 1,
.filename = try allocator.dupe(u8, "0001_test.log"),
.seq_start = 1,
.seq_end = 100,
.ts_start = 1000000,
.ts_end = 2000000,
.entries = 100,
.bytes = 50000,
.first_hash = [_]u8{'0'} ** 64,
.last_hash = [_]u8{'a'} ** 64,
.closed = true,
};
defer allocator.free(file_info.filename);
try index.addFile(file_info);
try std.testing.expectEqual(@as(usize, 1), index.files.items.len);
try std.testing.expectEqual(@as(u32, 2), index.getNextFileId());
// Find by seq
const found = index.findFileBySeq(50);
try std.testing.expect(found != null);
try std.testing.expectEqual(@as(u32, 1), found.?.id);
// Not found
const not_found = index.findFileBySeq(200);
try std.testing.expect(not_found == null);
}
test "Index JSON serialization" {
const allocator = std.testing.allocator;
var index = try Index.init(allocator, "mydb.sqlite");
defer index.deinit();
index.rotation.max_bytes = 50 * 1024 * 1024;
index.rotation.max_age_days = 15;
const json = try index.toJson();
defer allocator.free(json);
// Parse it back
var parsed = try Index.load(allocator, json);
defer parsed.deinit();
try std.testing.expectEqualStrings("mydb.sqlite", parsed.db_name);
try std.testing.expectEqual(@as(u64, 50 * 1024 * 1024), parsed.rotation.max_bytes);
try std.testing.expectEqual(@as(u32, 15), parsed.rotation.max_age_days);
}
test "generateFilename" {
const allocator = std.testing.allocator;
// Test with a known timestamp: 2024-12-08 14:32:15 UTC
const ts: i64 = 1733667135000000;
const filename = try generateFilename(allocator, 1, ts);
defer allocator.free(filename);
// Should be format: NNNN_YYYYMMDD_HHMMSS.log
try std.testing.expect(filename.len > 0);
try std.testing.expect(std.mem.startsWith(u8, filename, "0001_"));
try std.testing.expect(std.mem.endsWith(u8, filename, ".log"));
}

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//! Audit Log
//!
//! Main audit logging system that captures database operations via SQLite hooks.
const std = @import("std");
const Allocator = std.mem.Allocator;
const c = @import("../c.zig").c;
const Database = @import("../database.zig").Database;
const UpdateOperation = @import("../types.zig").UpdateOperation;
const Entry = @import("entry.zig").Entry;
const EntryBuilder = @import("entry.zig").EntryBuilder;
const Operation = @import("entry.zig").Operation;
const AuditContext = @import("context.zig").AuditContext;
const ContextEntryContext = @import("context.zig").EntryContext;
const Writer = @import("writer.zig").Writer;
const Index = @import("index.zig").Index;
const RotationConfig = @import("index.zig").RotationConfig;
/// Capture configuration
pub const CaptureConfig = struct {
/// Capture SQL statements
sql: bool = true,
/// Capture values before operation
before_values: bool = true,
/// Capture values after operation
after_values: bool = true,
/// Tables to include (null = all tables)
include_tables: ?[]const []const u8 = null,
/// Tables to exclude
exclude_tables: ?[]const []const u8 = null,
};
/// Audit log configuration
pub const Config = struct {
/// Directory for log files
log_dir: []const u8,
/// Rotation configuration
rotation: RotationConfig = .{},
/// Capture configuration
capture: CaptureConfig = .{},
/// Initial application name
app_name: ?[]const u8 = null,
/// Initial user
user: ?[]const u8 = null,
};
/// Pending operation (buffered until commit)
const PendingOp = struct {
op: Operation,
table: []const u8,
rowid: i64,
sql: ?[]const u8,
before: ?[]const u8,
after: ?[]const u8,
timestamp_us: i64,
fn deinit(self: *PendingOp, allocator: Allocator) void {
allocator.free(self.table);
if (self.sql) |s| allocator.free(s);
if (self.before) |b| allocator.free(b);
if (self.after) |a| allocator.free(a);
self.* = undefined;
}
};
/// Transaction buffer
const TxBuffer = struct {
allocator: Allocator,
tx_id: u64,
ops: std.ArrayListUnmanaged(PendingOp),
fn init(allocator: Allocator, tx_id: u64) TxBuffer {
return .{
.allocator = allocator,
.tx_id = tx_id,
.ops = .empty,
};
}
fn deinit(self: *TxBuffer) void {
for (self.ops.items) |*op| {
op.deinit(self.allocator);
}
self.ops.deinit(self.allocator);
self.* = undefined;
}
fn addOp(self: *TxBuffer, op: PendingOp) !void {
try self.ops.append(self.allocator, op);
}
fn clear(self: *TxBuffer) void {
for (self.ops.items) |*op| {
op.deinit(self.allocator);
}
self.ops.clearRetainingCapacity();
}
};
/// Audit Log system
pub const AuditLog = struct {
allocator: Allocator,
/// Database being audited
db: *Database,
/// Log writer
writer: Writer,
/// Context (user, app, etc.)
context: AuditContext,
/// Capture configuration
capture: CaptureConfig,
/// Current transaction buffer
tx_buffer: ?TxBuffer,
/// Transaction counter
tx_counter: u64,
/// Whether audit is enabled
enabled: bool,
/// Pre-update values cache (for capturing before values)
pre_update_cache: ?PreUpdateCache,
const Self = @This();
/// Pre-update cache for capturing values before update/delete
const PreUpdateCache = struct {
table: []const u8,
rowid: i64,
values_json: []const u8,
fn deinit(self: *PreUpdateCache, allocator: Allocator) void {
allocator.free(self.table);
allocator.free(self.values_json);
self.* = undefined;
}
};
/// Initialize audit log
/// IMPORTANT: After init, you must call `start()` to activate the hooks.
/// This is required because SQLite hooks store a pointer to this struct,
/// and the struct must be at its final memory location before hooks are installed.
pub fn init(allocator: Allocator, db: *Database, config: Config) !Self {
// Extract db name from path (for index)
const db_path = db.filename("main") orelse "unknown.db";
const db_name = std.fs.path.basename(db_path);
var writer = try Writer.init(allocator, config.log_dir, db_name);
errdefer writer.deinit();
var context = AuditContext.init(allocator);
errdefer context.deinit();
if (config.app_name) |app| {
try context.setApp(app);
}
if (config.user) |user| {
try context.setUser(user);
}
return Self{
.allocator = allocator,
.db = db,
.writer = writer,
.context = context,
.capture = config.capture,
.tx_buffer = null,
.tx_counter = 0,
.enabled = false, // Disabled until start() is called
.pre_update_cache = null,
};
}
/// Start audit logging by installing SQLite hooks.
/// Must be called after the AuditLog struct is at its final memory location.
pub fn start(self: *Self) void {
self.installHooks();
self.enabled = true;
}
pub fn deinit(self: *Self) void {
// Remove hooks
self.removeHooks();
// Clean up pre-update cache
if (self.pre_update_cache) |*cache| {
cache.deinit(self.allocator);
}
// Clean up transaction buffer
if (self.tx_buffer) |*buf| {
buf.deinit();
}
self.writer.deinit();
self.context.deinit();
self.* = undefined;
}
/// Set current user
pub fn setUser(self: *Self, user: ?[]const u8) !void {
try self.context.setUser(user);
}
/// Set application name
pub fn setApp(self: *Self, app: ?[]const u8) !void {
try self.context.setApp(app);
}
/// Enable/disable audit logging
pub fn setEnabled(self: *Self, enabled: bool) void {
self.enabled = enabled;
}
/// Force log rotation
pub fn rotate(self: *Self) !void {
try self.writer.rotate();
}
/// Flush pending writes
pub fn flush(self: *Self) !void {
try self.writer.flush();
}
/// Get statistics
pub fn stats(self: *const Self) Stats {
const writer_stats = self.writer.getStats();
return Stats{
.total_entries = writer_stats.total_entries,
.total_bytes = writer_stats.total_bytes,
.file_count = writer_stats.file_count,
};
}
// ========================================================================
// Hook handlers
// ========================================================================
fn installHooks(self: *Self) void {
const self_ptr = @intFromPtr(self);
// Pre-update hook (captures before values)
if (self.capture.before_values) {
_ = c.sqlite3_preupdate_hook(
self.db.handle,
preUpdateHookCallback,
@ptrFromInt(self_ptr),
);
}
// Update hook (captures operation)
_ = c.sqlite3_update_hook(
self.db.handle,
updateHookCallback,
@ptrFromInt(self_ptr),
);
// Commit hook
_ = c.sqlite3_commit_hook(
self.db.handle,
commitHookCallback,
@ptrFromInt(self_ptr),
);
// Rollback hook
_ = c.sqlite3_rollback_hook(
self.db.handle,
rollbackHookCallback,
@ptrFromInt(self_ptr),
);
}
fn removeHooks(self: *Self) void {
_ = c.sqlite3_preupdate_hook(self.db.handle, null, null);
_ = c.sqlite3_update_hook(self.db.handle, null, null);
_ = c.sqlite3_commit_hook(self.db.handle, null, null);
_ = c.sqlite3_rollback_hook(self.db.handle, null, null);
}
// Pre-update hook: capture before values
fn preUpdateHookCallback(
user_data: ?*anyopaque,
db_handle: ?*c.sqlite3,
op: c_int,
_: [*c]const u8, // db_name
table_name: [*c]const u8,
old_rowid: c.sqlite3_int64,
_: c.sqlite3_int64, // new_rowid
) callconv(.c) void {
const self: *Self = @ptrCast(@alignCast(user_data orelse return));
if (!self.enabled) return;
const table = std.mem.span(table_name);
if (!self.shouldCaptureTable(table)) return;
// Only capture before values for UPDATE and DELETE
const operation: c_int = op;
if (operation != c.SQLITE_UPDATE and operation != c.SQLITE_DELETE) return;
// Get column count
const col_count = c.sqlite3_preupdate_count(db_handle);
if (col_count <= 0) return;
// Build JSON for old values
var json_list: std.ArrayListUnmanaged(u8) = .empty;
defer json_list.deinit(self.allocator);
const writer = json_list.writer(self.allocator);
writer.writeByte('{') catch return;
var first = true;
var col: c_int = 0;
while (col < col_count) : (col += 1) {
var value: ?*c.sqlite3_value = null;
if (c.sqlite3_preupdate_old(db_handle, col, &value) != c.SQLITE_OK) continue;
if (value == null) continue;
if (!first) writer.writeAll(",") catch return;
first = false;
// Get column name (we'd need table info for this, use index for now)
writer.print("\"col{d}\":", .{col}) catch return;
writeValueAsJson(writer, value.?) catch return;
}
writer.writeByte('}') catch return;
// Cache the pre-update values
if (self.pre_update_cache) |*cache| {
cache.deinit(self.allocator);
}
self.pre_update_cache = PreUpdateCache{
.table = self.allocator.dupe(u8, table) catch return,
.rowid = old_rowid,
.values_json = json_list.toOwnedSlice(self.allocator) catch return,
};
}
// Update hook: capture operation
fn updateHookCallback(
user_data: ?*anyopaque,
op: c_int,
_: [*c]const u8, // db_name
table_name: [*c]const u8,
rowid: c.sqlite3_int64,
) callconv(.c) void {
const self: *Self = @ptrCast(@alignCast(user_data orelse return));
if (!self.enabled) return;
const table = std.mem.span(table_name);
if (!self.shouldCaptureTable(table)) return;
const operation: Operation = switch (op) {
c.SQLITE_INSERT => .INSERT,
c.SQLITE_UPDATE => .UPDATE,
c.SQLITE_DELETE => .DELETE,
else => return,
};
// Get before values from cache
var before_json: ?[]const u8 = null;
if (self.pre_update_cache) |*cache| {
if (std.mem.eql(u8, cache.table, table) and cache.rowid == rowid) {
before_json = self.allocator.dupe(u8, cache.values_json) catch null;
}
cache.deinit(self.allocator);
self.pre_update_cache = null;
}
// Create pending operation
const pending = PendingOp{
.op = operation,
.table = self.allocator.dupe(u8, table) catch {
if (before_json) |b| self.allocator.free(b);
return;
},
.rowid = rowid,
.sql = null, // SQL capture requires statement tracking
.before = before_json,
.after = null, // Would need post-update query
.timestamp_us = std.time.microTimestamp(),
};
// Ensure we have a transaction buffer
if (self.tx_buffer == null) {
self.tx_counter += 1;
self.tx_buffer = TxBuffer.init(self.allocator, self.tx_counter);
}
self.tx_buffer.?.addOp(pending) catch return;
}
// Commit hook: flush transaction buffer
fn commitHookCallback(user_data: ?*anyopaque) callconv(.c) c_int {
const self: *Self = @ptrCast(@alignCast(user_data orelse return 0));
if (!self.enabled) return 0;
if (self.tx_buffer) |*buf| {
// Write all pending operations
for (buf.ops.items) |*op| {
self.writeEntry(buf.tx_id, op) catch continue;
}
buf.deinit();
self.tx_buffer = null;
}
// Flush writer
self.writer.flush() catch {};
return 0; // 0 = allow commit
}
// Rollback hook: discard transaction buffer
fn rollbackHookCallback(user_data: ?*anyopaque) callconv(.c) void {
const self: *Self = @ptrCast(@alignCast(user_data orelse return));
if (self.tx_buffer) |*buf| {
buf.deinit();
self.tx_buffer = null;
}
}
// Write a single entry
fn writeEntry(self: *Self, tx_id: u64, op: *const PendingOp) !void {
var builder = EntryBuilder.init(self.allocator);
errdefer builder.deinit();
_ = builder.setSeq(self.writer.nextSeq());
_ = builder.setTimestamp(op.timestamp_us);
_ = builder.setTxId(tx_id);
_ = builder.setOp(op.op);
_ = try builder.setTable(op.table);
_ = builder.setRowid(op.rowid);
_ = builder.setPrevHash(self.writer.getLastHash());
// Get context
const ctx = self.context.toEntryContext() catch ContextEntryContext{
.user = null,
.app = null,
.host = null,
.pid = null,
};
_ = builder.setContext(.{
.user = ctx.user,
.app = ctx.app,
.host = ctx.host,
.pid = ctx.pid,
});
if (op.sql) |sql| {
_ = try builder.setSql(sql);
}
if (op.before) |before| {
_ = try builder.setBefore(before);
}
if (op.after) |after| {
_ = try builder.setAfter(after);
}
var entry = try builder.build();
defer entry.deinit(self.allocator);
builder.deinit();
try self.writer.write(&entry);
}
fn shouldCaptureTable(self: *const Self, table: []const u8) bool {
// Check exclude list first
if (self.capture.exclude_tables) |exclude| {
for (exclude) |excl| {
if (std.mem.eql(u8, table, excl)) return false;
}
}
// Check include list
if (self.capture.include_tables) |include| {
for (include) |incl| {
if (std.mem.eql(u8, table, incl)) return true;
}
return false;
}
return true;
}
};
/// Helper to write sqlite3_value as JSON
fn writeValueAsJson(writer: anytype, value: *c.sqlite3_value) !void {
const vtype = c.sqlite3_value_type(value);
switch (vtype) {
c.SQLITE_INTEGER => {
const val = c.sqlite3_value_int64(value);
try writer.print("{d}", .{val});
},
c.SQLITE_FLOAT => {
const val = c.sqlite3_value_double(value);
try writer.print("{d}", .{val});
},
c.SQLITE_TEXT => {
const len: usize = @intCast(c.sqlite3_value_bytes(value));
const text = c.sqlite3_value_text(value);
if (text) |t| {
try writer.writeByte('"');
const slice = t[0..len];
for (slice) |ch| {
switch (ch) {
'"' => try writer.writeAll("\\\""),
'\\' => try writer.writeAll("\\\\"),
'\n' => try writer.writeAll("\\n"),
'\r' => try writer.writeAll("\\r"),
'\t' => try writer.writeAll("\\t"),
else => try writer.writeByte(ch),
}
}
try writer.writeByte('"');
} else {
try writer.writeAll("null");
}
},
c.SQLITE_BLOB => {
// Encode as base64 or hex
const len: usize = @intCast(c.sqlite3_value_bytes(value));
const blob = c.sqlite3_value_blob(value);
if (blob) |b| {
const ptr: [*]const u8 = @ptrCast(b);
try writer.writeAll("\"<blob:");
try writer.print("{d}", .{len});
try writer.writeAll(">\"");
_ = ptr;
} else {
try writer.writeAll("null");
}
},
c.SQLITE_NULL => {
try writer.writeAll("null");
},
else => {
try writer.writeAll("null");
},
}
}
/// Statistics
pub const Stats = struct {
total_entries: u64,
total_bytes: u64,
file_count: usize,
};
test "AuditLog basic" {
// This test needs a real database
const allocator = std.testing.allocator;
// Create test directory
const tmp_dir = "/tmp/zsqlite_audit_log_test";
defer std.fs.cwd().deleteTree(tmp_dir) catch {};
// Open database
var db = Database.open(":memory:") catch return;
defer db.close();
// Initialize audit log
var audit = try AuditLog.init(allocator, &db, .{
.log_dir = tmp_dir,
.app_name = "test_app",
});
defer audit.deinit();
// Start hooks - must be done after audit is at final memory location
audit.start();
try audit.setUser("test_user");
// Create table and insert data
try db.exec("CREATE TABLE test (id INTEGER PRIMARY KEY, name TEXT)");
try db.exec("INSERT INTO test (name) VALUES ('Alice')");
try db.exec("UPDATE test SET name = 'Bob' WHERE id = 1");
try db.exec("DELETE FROM test WHERE id = 1");
// Flush
try audit.flush();
// Check stats
const stat = audit.stats();
// Note: In-memory DB with autocommit may not trigger hooks as expected
// This is a basic sanity test
_ = stat;
}

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//! Audit Log System
//!
//! External audit logging for zsqlite that provides:
//! - v1.0: Complete operation auditing with verifiable integrity (hash chain)
//! - v2.0: Time travel to any point in history (future)
//!
//! ## Features
//!
//! - Captures INSERT, UPDATE, DELETE operations
//! - Records before/after values
//! - Tracks context (user, app, host, pid)
//! - Hash chain for integrity verification
//! - Automatic file rotation by size/age
//! - JSON Lines format (human readable)
//!
//! ## Quick Start
//!
//! ```zig
//! const audit = @import("zsqlite").audit;
//!
//! // Initialize
//! var log = try audit.AuditLog.init(allocator, &db, .{
//! .log_dir = "./mydb_audit",
//! .app_name = "myapp",
//! });
//! defer log.deinit();
//!
//! // Set user after login
//! try log.setUser("alice");
//!
//! // Operations are captured automatically
//! try db.exec("INSERT INTO users (name) VALUES ('Bob')");
//!
//! // Verify integrity
//! var result = try audit.verifyChain(allocator, "./mydb_audit");
//! defer result.deinit(allocator);
//! if (!result.valid) {
//! std.debug.print("Corrupted at seq {}\n", .{result.first_invalid_seq});
//! }
//! ```
// Core types
pub const Entry = @import("entry.zig").Entry;
pub const EntryBuilder = @import("entry.zig").EntryBuilder;
pub const Operation = @import("entry.zig").Operation;
pub const Context = @import("entry.zig").Context;
// Context management
pub const AuditContext = @import("context.zig").AuditContext;
pub const EntryContext = @import("context.zig").EntryContext;
pub const OwnedEntryContext = @import("context.zig").OwnedEntryContext;
// Index and file management
pub const Index = @import("index.zig").Index;
pub const FileInfo = @import("index.zig").FileInfo;
pub const RotationConfig = @import("index.zig").RotationConfig;
pub const generateFilename = @import("index.zig").generateFilename;
// Writer
pub const Writer = @import("writer.zig").Writer;
pub const WriterStats = @import("writer.zig").Stats;
pub const WriterError = @import("writer.zig").WriterError;
// Main audit log
pub const AuditLog = @import("log.zig").AuditLog;
pub const Config = @import("log.zig").Config;
pub const CaptureConfig = @import("log.zig").CaptureConfig;
pub const Stats = @import("log.zig").Stats;
// Verification
pub const verify = @import("verify.zig");
pub const verifyChain = verify.verifyChain;
pub const quickCheck = verify.quickCheck;
pub const VerifyResult = verify.VerifyResult;
// Tests
test {
_ = @import("entry.zig");
_ = @import("context.zig");
_ = @import("index.zig");
_ = @import("writer.zig");
_ = @import("log.zig");
_ = @import("verify.zig");
}

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//! Audit Log Verification
//!
//! Verifies the integrity of audit logs by checking hash chains.
const std = @import("std");
const Allocator = std.mem.Allocator;
const Index = @import("index.zig").Index;
const FileInfo = @import("index.zig").FileInfo;
/// Verification result
pub const VerifyResult = struct {
/// Whether the entire chain is valid
valid: bool,
/// Total entries verified
entries_verified: u64,
/// Total files verified
files_verified: usize,
/// First invalid entry (if any)
first_invalid_seq: ?u64,
/// Error message (if any)
error_message: ?[]const u8,
pub fn deinit(self: *VerifyResult, allocator: Allocator) void {
if (self.error_message) |msg| {
allocator.free(msg);
}
self.* = undefined;
}
};
/// Verify the integrity of audit logs in a directory
pub fn verifyChain(allocator: Allocator, log_dir: []const u8) !VerifyResult {
// Load index
const index_path = try std.fs.path.join(allocator, &.{ log_dir, "index.json" });
defer allocator.free(index_path);
const index_data = std.fs.cwd().readFileAlloc(allocator, index_path, 10 * 1024 * 1024) catch |err| {
return VerifyResult{
.valid = false,
.entries_verified = 0,
.files_verified = 0,
.first_invalid_seq = null,
.error_message = try std.fmt.allocPrint(allocator, "Cannot read index.json: {}", .{err}),
};
};
defer allocator.free(index_data);
var index = Index.load(allocator, index_data) catch |err| {
return VerifyResult{
.valid = false,
.entries_verified = 0,
.files_verified = 0,
.first_invalid_seq = null,
.error_message = try std.fmt.allocPrint(allocator, "Invalid index.json: {}", .{err}),
};
};
defer index.deinit();
var total_entries: u64 = 0;
var expected_prev_hash: [64]u8 = [_]u8{'0'} ** 64; // Genesis
// Verify each file
for (index.files.items, 0..) |*file_info, file_idx| {
// Check chain continuity between files
if (file_idx > 0) {
if (!std.mem.eql(u8, &file_info.first_hash, &expected_prev_hash)) {
return VerifyResult{
.valid = false,
.entries_verified = total_entries,
.files_verified = file_idx,
.first_invalid_seq = file_info.seq_start,
.error_message = try std.fmt.allocPrint(
allocator,
"File chain broken at file {d}: expected prev_hash {s}, got {s}",
.{ file_info.id, expected_prev_hash, file_info.first_hash },
),
};
}
}
// Verify entries in file
const file_path = try std.fs.path.join(allocator, &.{ log_dir, file_info.filename });
defer allocator.free(file_path);
const result = try verifyFile(allocator, file_path, expected_prev_hash);
if (!result.valid) {
return VerifyResult{
.valid = false,
.entries_verified = total_entries + result.entries_verified,
.files_verified = file_idx,
.first_invalid_seq = result.first_invalid_seq,
.error_message = result.error_message,
};
}
total_entries += result.entries_verified;
expected_prev_hash = result.last_hash;
// Verify file's recorded last_hash matches
if (!std.mem.eql(u8, &file_info.last_hash, &result.last_hash)) {
return VerifyResult{
.valid = false,
.entries_verified = total_entries,
.files_verified = file_idx + 1,
.first_invalid_seq = null,
.error_message = try std.fmt.allocPrint(
allocator,
"File {d} last_hash mismatch: index says {s}, actual {s}",
.{ file_info.id, file_info.last_hash, result.last_hash },
),
};
}
}
return VerifyResult{
.valid = true,
.entries_verified = total_entries,
.files_verified = index.files.items.len,
.first_invalid_seq = null,
.error_message = null,
};
}
/// Result from verifying a single file
const FileVerifyResult = struct {
valid: bool,
entries_verified: u64,
first_invalid_seq: ?u64,
last_hash: [64]u8,
error_message: ?[]const u8,
};
/// Verify a single log file
fn verifyFile(allocator: Allocator, file_path: []const u8, expected_prev_hash: [64]u8) !FileVerifyResult {
const file_contents = std.fs.cwd().readFileAlloc(allocator, file_path, 100 * 1024 * 1024) catch |err| {
return FileVerifyResult{
.valid = false,
.entries_verified = 0,
.first_invalid_seq = null,
.last_hash = expected_prev_hash,
.error_message = try std.fmt.allocPrint(allocator, "Cannot read file: {}", .{err}),
};
};
defer allocator.free(file_contents);
var entries_verified: u64 = 0;
var current_prev_hash = expected_prev_hash;
var last_hash = expected_prev_hash;
var lines = std.mem.splitScalar(u8, file_contents, '\n');
while (lines.next()) |line| {
if (line.len == 0) continue;
// Parse JSON to extract hash fields and seq
const parse_result = parseEntryHashes(allocator, line) catch |err| {
return FileVerifyResult{
.valid = false,
.entries_verified = entries_verified,
.first_invalid_seq = null,
.last_hash = last_hash,
.error_message = try std.fmt.allocPrint(allocator, "JSON parse error: {}", .{err}),
};
};
defer {
if (parse_result.error_message) |msg| allocator.free(msg);
}
if (!parse_result.valid) {
return FileVerifyResult{
.valid = false,
.entries_verified = entries_verified,
.first_invalid_seq = parse_result.seq,
.last_hash = last_hash,
.error_message = parse_result.error_message,
};
}
// Verify prev_hash chain
if (!std.mem.eql(u8, &parse_result.prev_hash, &current_prev_hash)) {
return FileVerifyResult{
.valid = false,
.entries_verified = entries_verified,
.first_invalid_seq = parse_result.seq,
.last_hash = last_hash,
.error_message = try std.fmt.allocPrint(
allocator,
"Chain broken at seq {?d}: expected prev {s}, got {s}",
.{ parse_result.seq, current_prev_hash, parse_result.prev_hash },
),
};
}
// Verify hash
const computed_hash = try computeEntryHash(allocator, line);
if (!std.mem.eql(u8, &computed_hash, &parse_result.hash)) {
return FileVerifyResult{
.valid = false,
.entries_verified = entries_verified,
.first_invalid_seq = parse_result.seq,
.last_hash = last_hash,
.error_message = try std.fmt.allocPrint(
allocator,
"Hash mismatch at seq {?d}: computed {s}, stored {s}",
.{ parse_result.seq, computed_hash, parse_result.hash },
),
};
}
current_prev_hash = parse_result.hash;
last_hash = parse_result.hash;
entries_verified += 1;
}
return FileVerifyResult{
.valid = true,
.entries_verified = entries_verified,
.first_invalid_seq = null,
.last_hash = last_hash,
.error_message = null,
};
}
/// Result from parsing entry hashes
const ParseHashResult = struct {
valid: bool,
seq: ?u64,
prev_hash: [64]u8,
hash: [64]u8,
error_message: ?[]const u8,
};
/// Parse entry to extract hash fields
fn parseEntryHashes(allocator: Allocator, json_line: []const u8) !ParseHashResult {
const parsed = std.json.parseFromSlice(std.json.Value, allocator, json_line, .{}) catch |err| {
return ParseHashResult{
.valid = false,
.seq = null,
.prev_hash = undefined,
.hash = undefined,
.error_message = try std.fmt.allocPrint(allocator, "JSON parse failed: {}", .{err}),
};
};
defer parsed.deinit();
const root = parsed.value.object;
// Get seq
const seq: u64 = @intCast(root.get("seq").?.integer);
// Get hashes
const prev_hash_str = root.get("prev_hash").?.string;
const hash_str = root.get("hash").?.string;
if (prev_hash_str.len != 64 or hash_str.len != 64) {
return ParseHashResult{
.valid = false,
.seq = seq,
.prev_hash = undefined,
.hash = undefined,
.error_message = try std.fmt.allocPrint(allocator, "Invalid hash length", .{}),
};
}
var prev_hash: [64]u8 = undefined;
var hash: [64]u8 = undefined;
@memcpy(&prev_hash, prev_hash_str[0..64]);
@memcpy(&hash, hash_str[0..64]);
return ParseHashResult{
.valid = true,
.seq = seq,
.prev_hash = prev_hash,
.hash = hash,
.error_message = null,
};
}
/// Compute hash for an entry (excluding the hash field)
fn computeEntryHash(allocator: Allocator, json_line: []const u8) ![64]u8 {
// Parse, remove hash field, reserialize, hash
const parsed = try std.json.parseFromSlice(std.json.Value, allocator, json_line, .{});
defer parsed.deinit();
// Build JSON without hash field
var list: std.ArrayListUnmanaged(u8) = .empty;
defer list.deinit(allocator);
const writer = list.writer(allocator);
try writer.writeByte('{');
const root = parsed.value.object;
var first = true;
// Write fields in order, excluding "hash"
const fields = [_][]const u8{ "seq", "ts", "tx_id", "ctx", "op", "table", "rowid", "sql", "before", "after", "prev_hash" };
for (fields) |field_name| {
if (root.get(field_name)) |value| {
if (!first) try writer.writeByte(',');
first = false;
try writer.print("\"{s}\":", .{field_name});
try writeJsonValue(writer, value);
}
}
try writer.writeByte('}');
// Compute SHA-256
var hash: [32]u8 = undefined;
std.crypto.hash.sha2.Sha256.hash(list.items, &hash, .{});
return std.fmt.bytesToHex(hash, .lower);
}
/// Write a JSON value
fn writeJsonValue(writer: anytype, value: std.json.Value) !void {
switch (value) {
.null => try writer.writeAll("null"),
.bool => |b| try writer.writeAll(if (b) "true" else "false"),
.integer => |i| try writer.print("{d}", .{i}),
.float => |f| try writer.print("{d}", .{f}),
.string => |s| {
try writer.writeByte('"');
for (s) |ch| {
switch (ch) {
'"' => try writer.writeAll("\\\""),
'\\' => try writer.writeAll("\\\\"),
'\n' => try writer.writeAll("\\n"),
'\r' => try writer.writeAll("\\r"),
'\t' => try writer.writeAll("\\t"),
0x00...0x08, 0x0b, 0x0c, 0x0e...0x1f => try writer.print("\\u{x:0>4}", .{ch}),
else => try writer.writeByte(ch),
}
}
try writer.writeByte('"');
},
.array => |arr| {
try writer.writeByte('[');
for (arr.items, 0..) |item, i| {
if (i > 0) try writer.writeByte(',');
try writeJsonValue(writer, item);
}
try writer.writeByte(']');
},
.object => |obj| {
try writer.writeByte('{');
var iter = obj.iterator();
var i: usize = 0;
while (iter.next()) |entry| {
if (i > 0) try writer.writeByte(',');
try writer.print("\"{s}\":", .{entry.key_ptr.*});
try writeJsonValue(writer, entry.value_ptr.*);
i += 1;
}
try writer.writeByte('}');
},
.number_string => |s| try writer.writeAll(s),
}
}
/// Quick integrity check (just checks chain continuity in index)
pub fn quickCheck(allocator: Allocator, log_dir: []const u8) !bool {
const index_path = try std.fs.path.join(allocator, &.{ log_dir, "index.json" });
defer allocator.free(index_path);
const index_data = std.fs.cwd().readFileAlloc(allocator, index_path, 10 * 1024 * 1024) catch return false;
defer allocator.free(index_data);
var index = Index.load(allocator, index_data) catch return false;
defer index.deinit();
// Check file chain continuity in index
var prev_hash: [64]u8 = [_]u8{'0'} ** 64;
for (index.files.items) |*file| {
if (!std.mem.eql(u8, &file.first_hash, &prev_hash)) {
return false;
}
prev_hash = file.last_hash;
}
return true;
}
test "verify empty log" {
const allocator = std.testing.allocator;
const tmp_dir = "/tmp/zsqlite_verify_test";
defer std.fs.cwd().deleteTree(tmp_dir) catch {};
// Create directory with just index
std.fs.makeDirAbsolute(tmp_dir) catch {};
var index = try Index.init(allocator, "test.db");
defer index.deinit();
const json = try index.toJson();
defer allocator.free(json);
const index_path = try std.fs.path.join(allocator, &.{ tmp_dir, "index.json" });
defer allocator.free(index_path);
const file = try std.fs.cwd().createFile(index_path, .{});
defer file.close();
try file.writeAll(json);
// Verify
var result = try verifyChain(allocator, tmp_dir);
defer result.deinit(allocator);
try std.testing.expect(result.valid);
try std.testing.expectEqual(@as(u64, 0), result.entries_verified);
}
test "quickCheck" {
const allocator = std.testing.allocator;
const tmp_dir = "/tmp/zsqlite_quickcheck_test";
defer std.fs.cwd().deleteTree(tmp_dir) catch {};
std.fs.makeDirAbsolute(tmp_dir) catch {};
var index = try Index.init(allocator, "test.db");
defer index.deinit();
const json = try index.toJson();
defer allocator.free(json);
const index_path = try std.fs.path.join(allocator, &.{ tmp_dir, "index.json" });
defer allocator.free(index_path);
const file = try std.fs.cwd().createFile(index_path, .{});
defer file.close();
try file.writeAll(json);
const ok = try quickCheck(allocator, tmp_dir);
try std.testing.expect(ok);
}

363
src/audit/writer.zig Normal file
View file

@ -0,0 +1,363 @@
//! Audit Log Writer
//!
//! Manages writing audit entries to files with rotation support.
const std = @import("std");
const Allocator = std.mem.Allocator;
const Entry = @import("entry.zig").Entry;
const Index = @import("index.zig").Index;
const FileInfo = @import("index.zig").FileInfo;
const RotationConfig = @import("index.zig").RotationConfig;
const generateFilename = @import("index.zig").generateFilename;
pub const WriterError = error{
LogDirNotFound,
CannotCreateLogDir,
CannotCreateFile,
CannotWriteFile,
CannotWriteIndex,
CannotOpenFile,
FileCorrupted,
OutOfMemory,
InvalidPath,
} || std.fs.File.OpenError || std.fs.File.WriteError || std.posix.RealPathError;
/// Log file writer
pub const Writer = struct {
allocator: Allocator,
/// Log directory path
log_dir: []const u8,
/// Current log file handle
current_file: ?std.fs.File,
/// Current file path
current_path: ?[]const u8,
/// Index tracking all files
index: Index,
/// Current file's byte count
current_bytes: u64,
/// Current file's entry count
current_entries: u64,
/// Last hash written
last_hash: [64]u8,
/// Current sequence number
current_seq: u64,
const Self = @This();
/// Initialize writer with a log directory
pub fn init(allocator: Allocator, log_dir: []const u8, db_name: []const u8) !Self {
// Create log directory if it doesn't exist
std.fs.makeDirAbsolute(log_dir) catch |err| switch (err) {
error.PathAlreadyExists => {},
else => return WriterError.CannotCreateLogDir,
};
// Try to load existing index or create new one
const index_path = try std.fs.path.join(allocator, &.{ log_dir, "index.json" });
defer allocator.free(index_path);
var index: Index = undefined;
var last_hash: [64]u8 = [_]u8{'0'} ** 64;
var current_seq: u64 = 0;
if (std.fs.cwd().readFileAlloc(allocator, index_path, 10 * 1024 * 1024)) |data| {
defer allocator.free(data);
index = try Index.load(allocator, data);
last_hash = index.getLastHash();
current_seq = index.getLastSeq();
} else |_| {
index = try Index.init(allocator, db_name);
}
return Self{
.allocator = allocator,
.log_dir = try allocator.dupe(u8, log_dir),
.current_file = null,
.current_path = null,
.index = index,
.current_bytes = 0,
.current_entries = 0,
.last_hash = last_hash,
.current_seq = current_seq,
};
}
pub fn deinit(self: *Self) void {
if (self.current_file) |f| {
f.close();
}
if (self.current_path) |p| {
self.allocator.free(p);
}
self.index.deinit();
self.allocator.free(self.log_dir);
self.* = undefined;
}
/// Write an entry to the log
pub fn write(self: *Self, entry: *const Entry) !void {
// Ensure we have an open file
try self.ensureFile();
// Serialize entry to JSON
const json = try entry.toJson(self.allocator);
defer self.allocator.free(json);
// Write JSON line
const file = self.current_file.?;
try file.writeAll(json);
try file.writeAll("\n");
// Update counters
self.current_bytes += json.len + 1;
self.current_entries += 1;
self.last_hash = entry.hash;
self.current_seq = entry.seq;
// Update index
self.index.updateCurrentFile(
entry.seq,
entry.timestamp_us,
self.current_entries,
self.current_bytes,
entry.hash,
);
// Check if rotation is needed
if (self.shouldRotate()) {
try self.rotate();
}
}
/// Get the next sequence number
pub fn nextSeq(self: *Self) u64 {
return self.current_seq + 1;
}
/// Get the last hash for chain continuity
pub fn getLastHash(self: *const Self) [64]u8 {
return self.last_hash;
}
/// Force rotation
pub fn rotate(self: *Self) !void {
// Close current file
if (self.current_file) |f| {
f.close();
self.current_file = null;
}
// Mark current file as closed in index
self.index.closeCurrentFile();
// Save index
try self.saveIndex();
// Reset counters (will create new file on next write)
self.current_bytes = 0;
self.current_entries = 0;
if (self.current_path) |p| {
self.allocator.free(p);
self.current_path = null;
}
}
/// Flush any buffered data
pub fn flush(self: *Self) !void {
if (self.current_file) |f| {
try f.sync();
}
try self.saveIndex();
}
/// Get statistics
pub fn getStats(self: *const Self) Stats {
var total_entries: u64 = 0;
var total_bytes: u64 = 0;
for (self.index.files.items) |*file| {
total_entries += file.entries;
total_bytes += file.bytes;
}
return Stats{
.total_entries = total_entries,
.total_bytes = total_bytes,
.file_count = self.index.files.items.len,
.current_file_entries = self.current_entries,
.current_file_bytes = self.current_bytes,
};
}
// Private methods
fn ensureFile(self: *Self) !void {
if (self.current_file != null) return;
// Create new file
const now = std.time.microTimestamp();
const file_id = self.index.getNextFileId();
const filename = try generateFilename(self.allocator, file_id, now);
defer self.allocator.free(filename);
const file_path = try std.fs.path.join(self.allocator, &.{ self.log_dir, filename });
// Create and open file
const file = std.fs.cwd().createFile(file_path, .{ .exclusive = true }) catch {
self.allocator.free(file_path);
return WriterError.CannotCreateFile;
};
self.current_file = file;
self.current_path = file_path;
self.current_bytes = 0;
self.current_entries = 0;
// Add to index
const file_info = FileInfo{
.id = file_id,
.filename = try self.allocator.dupe(u8, filename),
.seq_start = self.current_seq + 1,
.seq_end = null,
.ts_start = now,
.ts_end = null,
.entries = 0,
.bytes = 0,
.first_hash = self.last_hash,
.last_hash = self.last_hash,
.closed = false,
};
defer self.allocator.free(file_info.filename);
try self.index.addFile(file_info);
}
fn shouldRotate(self: *const Self) bool {
// Check size
if (self.current_bytes >= self.index.rotation.max_bytes) {
return true;
}
// Check age (if we have entries)
if (self.current_entries > 0) {
if (self.index.getCurrentFile()) |file| {
const now = std.time.microTimestamp();
const age_us = now - file.ts_start;
const max_age_us: i64 = @as(i64, @intCast(self.index.rotation.max_age_days)) * 24 * 60 * 60 * 1_000_000;
if (age_us >= max_age_us) {
return true;
}
}
}
return false;
}
fn saveIndex(self: *Self) !void {
const json = try self.index.toJson();
defer self.allocator.free(json);
const index_path = try std.fs.path.join(self.allocator, &.{ self.log_dir, "index.json" });
defer self.allocator.free(index_path);
const file = std.fs.cwd().createFile(index_path, .{}) catch {
return WriterError.CannotWriteIndex;
};
defer file.close();
file.writeAll(json) catch {
return WriterError.CannotWriteIndex;
};
}
};
/// Writer statistics
pub const Stats = struct {
total_entries: u64,
total_bytes: u64,
file_count: usize,
current_file_entries: u64,
current_file_bytes: u64,
};
test "Writer basic operations" {
const allocator = std.testing.allocator;
// Use temp directory
const tmp_dir = "/tmp/zsqlite_audit_test";
defer std.fs.cwd().deleteTree(tmp_dir) catch {};
var writer = try Writer.init(allocator, tmp_dir, "test.db");
defer writer.deinit();
// Create and write an entry
const EntryBuilder = @import("entry.zig").EntryBuilder;
var builder = EntryBuilder.init(allocator);
_ = builder.setSeq(writer.nextSeq());
_ = builder.setTimestampNow();
_ = builder.setTxId(1);
_ = builder.setOp(.INSERT);
_ = try builder.setTable("test_table");
_ = builder.setRowid(1);
_ = builder.setPrevHash(writer.getLastHash());
var entry = try builder.build();
defer entry.deinit(allocator);
builder.deinit();
try writer.write(&entry);
// Check stats
const stats = writer.getStats();
try std.testing.expectEqual(@as(u64, 1), stats.total_entries);
try std.testing.expect(stats.total_bytes > 0);
try std.testing.expectEqual(@as(usize, 1), stats.file_count);
// Flush and verify file exists
try writer.flush();
const index_exists = std.fs.cwd().access(tmp_dir ++ "/index.json", .{});
try std.testing.expect(index_exists != error.FileNotFound);
}
test "Writer rotation" {
const allocator = std.testing.allocator;
const tmp_dir = "/tmp/zsqlite_audit_rotation_test";
defer std.fs.cwd().deleteTree(tmp_dir) catch {};
var writer = try Writer.init(allocator, tmp_dir, "test.db");
defer writer.deinit();
// Set very small rotation threshold
writer.index.rotation.max_bytes = 100;
const EntryBuilder = @import("entry.zig").EntryBuilder;
// Write entries until rotation
var i: u32 = 0;
while (i < 10) : (i += 1) {
var builder = EntryBuilder.init(allocator);
_ = builder.setSeq(writer.nextSeq());
_ = builder.setTimestampNow();
_ = builder.setTxId(1);
_ = builder.setOp(.INSERT);
_ = try builder.setTable("test_table");
_ = builder.setRowid(@intCast(i));
_ = try builder.setAfter("{\"value\":12345678901234567890}");
_ = builder.setPrevHash(writer.getLastHash());
var entry = try builder.build();
defer entry.deinit(allocator);
builder.deinit();
try writer.write(&entry);
}
try writer.flush();
// Should have multiple files due to rotation
const stats = writer.getStats();
try std.testing.expect(stats.file_count > 1);
}

View file

@ -43,6 +43,7 @@ pub const vtable = @import("vtable.zig");
// Advanced features // Advanced features
pub const serialize = @import("serialize.zig"); pub const serialize = @import("serialize.zig");
pub const session = @import("session.zig"); pub const session = @import("session.zig");
pub const audit = @import("audit/mod.zig");
// Re-export C bindings (for advanced users) // Re-export C bindings (for advanced users)
pub const c = c_mod.c; pub const c = c_mod.c;
@ -118,6 +119,12 @@ pub const applyChangeset = session.applyChangeset;
pub const invertChangeset = session.invertChangeset; pub const invertChangeset = session.invertChangeset;
pub const concatChangesets = session.concatChangesets; pub const concatChangesets = session.concatChangesets;
// Re-export audit types
pub const AuditLog = audit.AuditLog;
pub const AuditConfig = audit.Config;
pub const AuditEntry = audit.Entry;
pub const verifyAuditChain = audit.verifyChain;
// Re-export snapshot type from Database // Re-export snapshot type from Database
pub const Snapshot = Database.Snapshot; pub const Snapshot = Database.Snapshot;
@ -1718,3 +1725,8 @@ test "session enable/disable" {
try db.exec("INSERT INTO test VALUES (2)"); try db.exec("INSERT INTO test VALUES (2)");
try std.testing.expect(!sess.isEmpty()); try std.testing.expect(!sess.isEmpty());
} }
// Include audit module tests
test {
_ = audit;
}