lightning-dissector

A wireshark plugin to analyze communication between Lightning Network nodes

Installation

First of all, you have to make sure that luarocks for Lua 5.2 is installed.
Here is how to build it. (You should set --lua-version=5.2 option when doing ./configure.)
And you'll need Lua library and headers. (if Ubuntu you can get it by apt install lua5.2 liblua5.2-dev)

Other requirements:

• libpcre (apt install libpcre3-dev)

git clone https://github.com/nayutaco/lightning-dissector.git --recursive
cd lightning-dissector
luarocks --local make
mkdir -p ~/.config/wireshark/plugins
ln -s ~/.luarocks/share/lua/5.2/lightning-dissector/wireshark-plugin.lua ~/.config/wireshark/plugins/lightning-dissector.lua

When a big BOLT message comes, lightning-dissector outputs a big message to Wireshark. (#25) Therefore, you might have to apply these patches to Wireshark source code.

diff --git epan/proto.h epan/proto.h
index afe8dae6e2..81e1e74a60 100644
--- epan/proto.h
+++ epan/proto.h
@@ -60,7 +60,7 @@ extern "C" {
 WS_DLL_PUBLIC int hf_text_only;

 /** the maximum length of a protocol field string representation */
-#define ITEM_LABEL_LENGTH	240
+#define ITEM_LABEL_LENGTH	10000

 #define ITEM_LABEL_UNKNOWN_STR  "Unknown"

Setup

Setup TCP ports (optional)

On Bitcoin mainnet or testnet, your lightning node will always bind to TCP port 9735. In that case you don't need to configure anything, by default the dissector will analyze packets on port 9735.

However, if you're running some tests on a local network and have nodes binding to other ports than 9735, you need to configure Wireshark to inspect those ports.

Go to Analyze -> Decode As... to add TCP ports to be analyzed by the dissector.

c-lightning (beta)

git clone https://github.com/arowser/lightning -b dissector
cd lightning
./configure  --enable-dissector
make -j
make install  # optional

Eclair

Eclair uses logback to configure its logs. Logback uses a configuration file that can be updated while the node is running. The default configuration can be found in eclair-node/src/main/resources/logback.xml.

To dump encryption keys for the lightning-dissector:

• copy logback.xml to your node's data directory (by default ~/.eclair)
• update the logger section named keylog: set its level to DEBUG (instead of OFF)
• run your node with the -Dlogback.configurationFile option pointing to your modified logback.xml (for example -Dlogback.configurationFile=/home/lightning-master/.eclair/logback.xml)

The keylog section of your logback.xml file should look like:

<logger level="DEBUG" name="keylog" additivity="false">
  <appender-ref ref="KEYLOG"/>
</logger>

You can then configure lightning-dissector's location for the key log by Protocols -> LIGHTNING -> Eclair log file (~/.eclair/keys.log by default).

Ptarmigan

You need to build ptarmigan with developer mode enabled.

sed -i 's/ENABLE_DEVELOPER_MODE=0/ENABLE_DEVELOPER_MODE=1/g' options.mak
make full

Set $LIGHTNINGKEYLOGFILE before starting ptarmigan.
ptarmigan dumps decryption keys to there.

mkdir ~/.cache/ptarmigan
export LIGHTNINGKEYLOGFILE=~/.cache/ptarmigan/keys.log

You should set $LIGHTNINGKEYLOGFILE value and Protocols -> LIGHTNING -> Key log file preference same. (~/.cache/ptarmigan/keys.log by default)

lnd (beta)

You have to start lnd at your $HOME.

go get -d github.com/lightningnetwork/lnd
cd $GOPATH/src/github.com/lightningnetwork/lnd
git remote add nakajo2011 https://github.com/nakajo2011/lnd.git
git fetch nakajo2011 dissector
git checkout nakajo2011/dissector
make && make install

Status

Supported implementations

Currently, lightning-dissector can decrypt messages sent from

• c-lightning
• lnd
• eclair
• ptarmigan

If you are developer of some BOLT implementation, I need your help!
You can make your BOLT implementation support lightning-dissector by dumping key log file, or writing a new SecretManager.