private void setBlockchainVariable(
        final KeyValueStorageTransaction blockchainTransaction,
        final Bytes prefix,
        final Bytes key,
        final Bytes value) {
      blockchainTransaction.put(
          Bytes.concatenate(prefix, key).toArrayUnsafe(), value.toArrayUnsafe());
    }
The Hash sub command for password.
app/src/main/java/org/hyperledger/besu/cli/subcommands/storage/StorageSubCommand.java