Prem Chaitanya Prathi bd65c116bb
feat(mix): DoS protection + libp2p v2.0.0 + stateless RLN + tests (rebased onto #3935)
Squash of 13 commits from feat/mix-dos-protection-libp2p-v2.0.0 onto the
logos_delivery/ folder-restructure base from #3935 (build-messaging-folder).

Original commit history (squashed):
- d8e6dcef feat(mix): integrate mix protocol with extended kademlia + RLN spam protection
- fb72f18d refactor(mix): split DoS-protection self-registration into background retry
- d8bbef0c feat(mix): bump libp2p stack to v2.0.0 + adopt stateless RLN spam protection
- 2f24448a fix(tests): use HmacDrbgContext.new() instead of crypto.newRng()
- 5a21455c fix(ci): regen nimble.lock for v2.0.0 + disambiguate rng in wakucore
- 03ef02a2 fix(tests): wrap HmacDrbgContext via newBearSslRng for libp2p v2.0.0
- 167ab1df fix(nix): regenerate deps.nix from updated nimble.lock
- 97a27222 fix(tests): wrap or pass Rng correctly for 3-arg PrivateKey.random
- 5561fcb5 fix(tests): replace removed newStandardSwitch with SwitchBuilder
- ba39ee4a fix(tests): libp2p v2.0.0 API migrations across test suite
- 328e11df fix: gitignore test binaries + remove accidentally-committed binary
- cc712444 fix(tests): more v2.0.0 API migrations (rng template, PeerId.random, etc.)
- 412d97a9 fix(tests): unblock CI — nph, excise orphan waku_noise, complete v2.0.0 Rng migration

Conflict resolutions (#3935 → ours):
- 11 import-path migrations: waku/X → logos_delivery/waku/X
- waku_node/waku_node/relay.nim: dropped our `registerRelayHandler` proc
  (relocated to subscription_manager.nim by #3935; see cascade fix below)
- factory/builder.nim: combined both sides' new imports (net_config + waku_switch)
- factory/conf_builder/mix_conf_builder.nim: libp2p_mix package (not libp2p/protocols/mix)
- waku_mix/protocol.nim: combined paths + our mix_rln_spam_protection/relay/nimchronos imports
- 3 test files: dropped noise_utils import (replicates noise excision from original PR)
- 2 UA file moves: option_shims.nim and waku_mix_coordination.nim added at new paths

Cascade fixes (#3935 lost our work, restored):
- subscription_manager.nim: added `mixHandler` to #3935's `registerRelayHandler`,
  and added `waku_mix` to its imports. Without this, mix messages were silently
  dropped from the relay handler chain.
- config.nims: option_shims auto-import path migrated to logos_delivery/...

Validation:
- nph check on all 82 staged .nim files: clean (0 reformats needed)
- wakunode2 build: exit 0, 38 MB binary
- (sim PASS confirmed in earlier identical-state run: 5/5 mix init,
  5 RLN proofs gen/verify, 0 errors)

Backup tag at original tip: backup/3931-pre-3935-rebase (412d97a9).
2026-06-22 14:20:58 +05:30

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3.3 KiB
Markdown

# Mixnet simulation
## Aim
Simulate a local mixnet along with a chat app to publish using mix.
This is helpful to test any changes during development.
## Simulation Details
The simulation includes:
1. A 5-node mixnet where `run_mix_node.sh` is the bootstrap node for the other 4 nodes
2. Two chat app instances that publish messages using lightpush protocol over the mixnet
### Available Scripts
| Script | Description |
| ------------------ | ------------------------------------------ |
| `run_mix_node.sh` | Bootstrap mix node (must be started first) |
| `run_mix_node1.sh` | Mix node 1 |
| `run_mix_node2.sh` | Mix node 2 |
| `run_mix_node3.sh` | Mix node 3 |
| `run_mix_node4.sh` | Mix node 4 |
| `run_chat_mix.sh` | Chat app instance 1 |
| `run_chat_mix1.sh` | Chat app instance 2 |
| `build_setup.sh` | Build and generate RLN credentials |
## Prerequisites
Before running the simulation, build `wakunode2` and `chat2mix`:
```bash
cd <repo-root-dir>
source env.sh
make wakunode2 chat2mix
```
## RLN Spam Protection Setup
Generate RLN credentials and the shared Merkle tree for all nodes:
```bash
cd simulations/mixnet
./build_setup.sh
```
This script will:
1. Build and run the `setup_credentials` tool
2. Generate RLN credentials for all nodes (5 mix nodes + 2 chat clients)
3. Create `rln_tree.db` - the shared Merkle tree with all members
4. Create keystore files (`rln_keystore_{peerId}.json`) for each node
**Important:** All scripts must be run from this directory (`simulations/mixnet/`) so they can access their credentials and tree file.
To regenerate credentials (e.g., after adding new nodes), run `./build_setup.sh` again - it will clean up old files first.
## Usage
### Step 1: Start the Mix Nodes
Start the bootstrap node first (in a separate terminal):
```bash
./run_mix_node.sh
```
Look for the following log lines to ensure the node started successfully:
```log
INF mounting mix protocol topics="waku node"
INF Node setup complete topics="wakunode main"
```
Verify RLN spam protection initialized correctly by checking for these logs:
```log
INF Initializing MixRlnSpamProtection
INF MixRlnSpamProtection initialized, waiting for sync
DBG Tree loaded from file
INF MixRlnSpamProtection started
```
Then start the remaining mix nodes in separate terminals:
```bash
./run_mix_node1.sh
./run_mix_node2.sh
./run_mix_node3.sh
./run_mix_node4.sh
```
### Step 2: Start the Chat Applications
Once all 5 mix nodes are running, start the first chat app:
```bash
./run_chat_mix.sh
```
Enter a nickname when prompted:
```bash
pubsub topic is: /waku/2/rs/2/0
Choose a nickname >>
```
Once you see the following log, the app is ready to publish messages over the mixnet:
```bash
Welcome, test!
Listening on
/ip4/<local-network-ip>/tcp/60000/p2p/16Uiu2HAkxDGqix1ifY3wF1ZzojQWRAQEdKP75wn1LJMfoHhfHz57
ready to publish messages now
```
Start the second chat app in another terminal:
```bash
./run_chat_mix1.sh
```
### Step 3: Test Messaging
Once both chat apps are running, send a message from one and verify it is received by the other.
To exit the chat apps, enter `/exit`:
```bash
>> /exit
quitting...
```