thakares
4b27a342d1
ARCHITECTURE.md - Full component map with ASCII diagram - Complete session lifecycle (init + heartbeat + failure path) - Cryptographic protocol spec (hash chain formula, canonical JSON) - Stack machine instruction set table with stack effects - Behavioral validation thresholds - SQLite schema, threat model summary, module reference DEPLOYMENT.md - Build instructions (WASM + server + convenience script) - native binary, systemd (with hardened sandbox notes), Docker - nginx, Nginx Proxy Manager, and HAProxy reverse proxy configs - Integration options (sidecar vs proxy-only) - Full configuration table with all constants - Observability (RUST_LOG levels), health check, security checklist API.md - Full /init and /hb request/response schemas with field tables - Canonical signing payload specification - Complete validation rules table (all 13 rejection conditions) - Hash chain byte-level specification - WASM exported function reference THREAT_MODEL.md - Four attacker profiles (script kiddie → sophisticated adversary) - Eight attack vectors with mitigations (replay, forgery, hijack, DoS…) - Explicit out-of-scope limitations - Operational security notes (CORS, TLS, log level, SQLite)
217 lines
6.9 KiB
Markdown
217 lines
6.9 KiB
Markdown
# ChronoSeal — API Reference
|
||
|
||
## Base URL
|
||
|
||
All endpoints are relative to the server root. In development: `http://localhost:3000`.
|
||
In production: your HTTPS domain via reverse proxy.
|
||
|
||
---
|
||
|
||
## Endpoints
|
||
|
||
### `POST /init`
|
||
|
||
Initialise a new session. Called once per page load, immediately after the
|
||
WASM module generates an Ed25519 keypair.
|
||
|
||
#### Request
|
||
|
||
```http
|
||
POST /init
|
||
Content-Type: application/json
|
||
```
|
||
|
||
```json
|
||
{
|
||
"public_key": "hex-encoded 32-byte Ed25519 verifying key"
|
||
}
|
||
```
|
||
|
||
| Field | Type | Description |
|
||
|---|---|---|
|
||
| `public_key` | `string` | Hex-encoded 32-byte Ed25519 verifying key generated by the WASM module |
|
||
|
||
#### Response `200 OK`
|
||
|
||
```json
|
||
{
|
||
"session_id": "64-char hex string (32 bytes)",
|
||
"salt": "32-char hex string (16 bytes)",
|
||
"opcodes_b64": "base64-encoded VM program (8–16 opcodes)",
|
||
"initial_hash": "64-char hex string (32 bytes Blake3)",
|
||
"expires_at": 1234567890123
|
||
}
|
||
```
|
||
|
||
| Field | Type | Description |
|
||
|---|---|---|
|
||
| `session_id` | `string` | Opaque session identifier; include in every heartbeat |
|
||
| `salt` | `string` | Initial salt; used to compute `H(0)` and first `H(1)` |
|
||
| `opcodes_b64` | `string` | Base64 VM program; execute with `run_program()` on every heartbeat |
|
||
| `initial_hash` | `string` | `H(0) = Blake3(session_id ║ pub_key ║ salt)`; the first `prev_hash` |
|
||
| `expires_at` | `number` | Unix timestamp in milliseconds; session expires after 30 minutes of inactivity |
|
||
|
||
#### Error
|
||
|
||
Returns `500 Internal Server Error` only on server-side failures (DB errors,
|
||
invalid public key length). No meaningful error body is returned.
|
||
|
||
---
|
||
|
||
### `POST /hb`
|
||
|
||
Submit a heartbeat. Called every 12–25 seconds with uniform random jitter.
|
||
|
||
#### Request
|
||
|
||
```http
|
||
POST /hb
|
||
Content-Type: application/json
|
||
```
|
||
|
||
```json
|
||
{
|
||
"session_id": "64-char hex",
|
||
"prev_hash": "64-char hex",
|
||
"timestamp": 1234567890123,
|
||
"entropy_data": {
|
||
"events": [
|
||
{ "x": 412.0, "y": 308.5, "t": 1234.567 },
|
||
{ "x": 415.2, "y": 310.1, "t": 1285.123 }
|
||
]
|
||
},
|
||
"stack_state": {
|
||
"stack": [2971406957, 1234567890],
|
||
"ip": 42
|
||
},
|
||
"fingerprint": {
|
||
"aspectRatio": "1.7777777778",
|
||
"devicePixelRatio": "2",
|
||
"hardwareConcurrency": 8
|
||
},
|
||
"signature": "128-char hex Ed25519 signature"
|
||
}
|
||
```
|
||
|
||
| Field | Type | Description |
|
||
|---|---|---|
|
||
| `session_id` | `string` | Session ID from `/init` |
|
||
| `prev_hash` | `string` | Hash chain head from previous heartbeat (or `initial_hash` for the first) |
|
||
| `timestamp` | `number` | `Date.now()` in milliseconds; must be within ±30s of server time |
|
||
| `entropy_data.events` | `array` | Mouse events since previous heartbeat; each has `x`, `y` (px), `t` (performance.now ms) |
|
||
| `stack_state.stack` | `array` | `u32[]` result of executing the VM program |
|
||
| `stack_state.ip` | `number` | Instruction pointer after execution |
|
||
| `fingerprint.aspectRatio` | `string` | `(screen.width / screen.height).toFixed(10)` |
|
||
| `fingerprint.devicePixelRatio` | `string` | `String(window.devicePixelRatio)` |
|
||
| `fingerprint.hardwareConcurrency` | `number` | `navigator.hardwareConcurrency \|\| 1` |
|
||
| `signature` | `string` | Hex-encoded 64-byte Ed25519 signature over the canonical payload |
|
||
|
||
#### Canonical Signing Payload
|
||
|
||
The client signs the following JSON object. Top-level keys must be sorted
|
||
alphabetically. Nested object keys follow their natural serialisation order.
|
||
|
||
```json
|
||
{
|
||
"entropyData": { "events": [{ "t": …, "x": …, "y": … }] },
|
||
"fingerprint": { "aspectRatio": "…", "devicePixelRatio": "…", "hardwareConcurrency": … },
|
||
"prevHash": "…",
|
||
"sessionId": "…",
|
||
"stackState": { "ip": …, "stack": […] },
|
||
"timestamp": …
|
||
}
|
||
```
|
||
|
||
Note: field names in the signing payload use camelCase (`sessionId`,
|
||
`prevHash`, `entropyData`, `stackState`) while the request body uses
|
||
snake_case (`session_id`, `prev_hash`, `entropy_data`, `stack_state`).
|
||
|
||
#### Response `200 OK` — Accepted
|
||
|
||
```json
|
||
{
|
||
"status": "ok",
|
||
"next_salt": "32-char hex string (16 bytes)"
|
||
}
|
||
```
|
||
|
||
The client must:
|
||
1. Capture `sentSalt = currentSalt` before updating.
|
||
2. Set `currentSalt = next_salt`.
|
||
3. Compute `prevHash = compute_next_hash(prevHash, timestamp, entropyJson, stackStateJson, sentSalt)`.
|
||
|
||
#### Response `200 OK` — Rejected
|
||
|
||
```json
|
||
{
|
||
"status": "ok"
|
||
}
|
||
```
|
||
|
||
`next_salt` is absent. The response body is intentionally identical in
|
||
structure. Rejections are silent — the caller cannot distinguish a validation
|
||
failure from a rate limit hit or an expired session.
|
||
|
||
The client should log a warning and continue scheduling heartbeats (they will
|
||
continue to fail until the page is reloaded and a new session is established).
|
||
|
||
---
|
||
|
||
## Validation Rules (Server-Side)
|
||
|
||
Heartbeats are rejected (silently) if any of the following checks fail:
|
||
|
||
| Check | Condition for rejection |
|
||
|---|---|
|
||
| Rate limit | > 5 requests per 10-second window for this `session_id` |
|
||
| Session not found | `session_id` not in SQLite |
|
||
| Session expired | `current_time_ms > expires_at` |
|
||
| Signature invalid | Ed25519 verification fails against stored public key |
|
||
| Hash chain broken | `hex(prev_hash) ≠ stored last_hash` |
|
||
| Timestamp drift | `\|server_now_ms - timestamp\| > 30 000` |
|
||
| Insufficient mouse events | `events.len() < 3` |
|
||
| Insufficient mouse distance | `total_dist < 10.0 px` |
|
||
| Mouse speed too high | `total_dist / total_time_ms > 2.0 px/ms` |
|
||
| No mouse pauses | `pause_count < 1` |
|
||
| Invalid aspect ratio | `ar < 0.5` or `ar > 3.0` |
|
||
| Invalid devicePixelRatio | `dpr ≤ 0.0` or `dpr > 5.0` |
|
||
| Zero hardwareConcurrency | `hardware_concurrency == 0` |
|
||
|
||
---
|
||
|
||
## Hash Chain Specification
|
||
|
||
```
|
||
H(0) = Blake3( session_id_bytes ║ pub_key_bytes ║ salt₀_bytes )
|
||
|
||
H(n) = Blake3(
|
||
saltₙ₋₁_bytes
|
||
║ H(n-1)_bytes
|
||
║ timestamp_u64_le_bytes
|
||
║ Blake3( UTF-8( JSON(entropy_data) ) )
|
||
║ Blake3( UTF-8( JSON(stack_state) ) )
|
||
)
|
||
```
|
||
|
||
All inputs are concatenated in the order shown. `timestamp` is encoded as a
|
||
64-bit unsigned integer in little-endian byte order. JSON serialisation of
|
||
`entropy_data` and `stack_state` uses the field order defined by the shared
|
||
Rust types (serde derive, no custom ordering).
|
||
|
||
---
|
||
|
||
## WASM API
|
||
|
||
The WASM module (`antibot_wasm`) exports the following functions to JavaScript:
|
||
|
||
| Function | Signature | Description |
|
||
|---|---|---|
|
||
| `generate_keypair()` | `() → string` | Generate Ed25519 keypair; return hex public key. Private key stored in WASM memory. |
|
||
| `get_public_key()` | `() → string` | Return hex public key, or `""` if not initialised. |
|
||
| `sign_message(msg)` | `(string) → string` | Sign UTF-8 string; return hex signature, or `""` if not initialised. |
|
||
| `compute_next_hash(prev, ts, entropy, stack, salt)` | `(string, u64, string, string, string) → string` | Compute next Blake3 chain hash; all inputs/output hex or JSON strings. |
|
||
| `run_program(b64)` | `(string) → JsValue` | Execute base64 VM program; return `{ stack: u32[], ip: number }`. |
|
||
|
||
All functions return empty strings on error rather than panicking.
|
||
Callers must check for empty return values before using the result.
|