🗝️Obol Key Splitting

These instructions are used by Ether.fi to split the keys into keyshares for the Obol DVT validators.

As a solo staker, you do not need to follow or even understand the steps, but they are provided here for your interest.

• Step 1: Clone the charon repo

• Step 2: Create a directory containing keys to split

• Step 3: Split the keys into keyshares

Step 1: Clone the charon repo

Clone the charon repo into a new directory called charon-key-splitter.

cd ~
mkdir charon-key-splitter
cd charon-key-splitter
git clone https://github.com/ObolNetwork/charon.git .
mkdir split_keys

Step 2: Create a directory containing keys to split

Copy the existing validator keystore.json files into this new folder. Alongside them, with a matching filename but ending with .txt should be the password to the keystore. E.g., keystore-0.json keystore-0.txt. These matching .txt files can be generated with a bash script.

At the start of this process, you should have a file tree that looks something like this.

├── charon-key-splitter
      ├── split_keys
          ├── keystore-0.json
          ├── keystore-1.json
          ...
          ├── keystore-*.json

Create the bash script file.

cd split_keys
vim generate_txt_files.sh

#!/bin/bash

# Get the input string (password) from the user
echo "Enter the string (password) to be used in all the .txt files:"
read input_string

# Iterate through all .json files in the directory
for file in *.json; do
    # Check if the file is a regular file (not a directory)
    if [[ -f "$file" ]]; then
        # Get the file name without the extension
        filename="${file%.*}"
        # Create a .txt file with the same name and add the input string to it
        echo "$input_string" > "${filename}.txt"
    fi
done

Save this script and make it executable.

chmod +x generate_txt_files.sh

Run the script.

./generate_txt_files.sh

At the end of this process, you should have a tree like this.

├── split_keys
    ├── keystore-0.json
    ├── keystore-0.txt
    ├── keystore-1.json
    ├── keystore-1.txt
    ...
    ├── keystore-*.json
    ├── keystore-*.txt

Step 3: Split the keys into keyshares

Split the validator keys into keyshares.

CHARON_VERSION=                # E.g. v0.16.0
NETWORK=                       # E.g. goerli
CLUSTER_NAME=                  # E.g. EtherfiSoloStaker
WITHDRAWAL_ADDRESS=            # Set withdrawal address
FEE_RECIPIENT_ADDRESS=         # Set fee recipient address
THRESHOLD=                     # E.g. 3
NODES=                         # E.g. 4                

docker run --rm -v $(pwd):/opt/charon obolnetwork/charon:${CHARON_VERSION} create cluster --name="${CLUSTER_NAME}" --network="${NETWORK}" --withdrawal-addresses="${WITHDRAWAL_ADDRESS}" --fee-recipient-addresses="${FEE_RECIPIENT_ADDRESS}" --split-existing-keys --split-keys-dir=/opt/charon/split_keys --threshold ${THRESHOLD} --nodes ${NODES}

In the .charon directory there will now be a cluster directory containing sub-directories, each named node0, node1, etc.

I can't see the .charon directory?! 👀

On most filesystems, files and directories that start with a . are hidden by default.

On a Unix system (Mac or Linux) on the command line you can see hidden files and directories using the -a flag for the ls command:

ls -la

.charon/cluster/
├─ node[0-*]/                   Directory for each node
   ├─ charon-enr-private-key    Charon networking private key for node authentication
   ├─ cluster-lock.json         Cluster lock defines the cluster lock file which is signed by all nodes
   ├─ deposit-data.json         Deposit data file is used to activate a Distributed Validator on DV Launchpad
   ├─ validator_keys            Validator keystores and password
      ├─ keystore-*.json        Validator private share key for duty signing
      ├─ keystore-*.txt         Keystore password files for keystore-*.json

Each solo staker participate will receive one of these directories in a compressed format. The exact format depends on the machine being used. The file formats needed for Avado and Dappnode machines are slightly different and are explained below.

Avado File Format

Avado requires the files to be uploaded in a .zip format.

Make sure you are in the .charon/cluster/ directory with all the node* directories.

For each node directory, compress the folder using the following command:

zip -r node0.zip node0

Dappnode File Format