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Last update: December 14, 2020

Create a permissioned network

The following steps set up a permissioned network with local node and account permissions. The network uses the Clique Proof of Authority consensus protocol.

Important

A permissioned Ethereum network as described here is not protected against all attack vectors. We recommend applying defense in depth to protect your infrastructure.

Prerequisites

Hyperledger Besu

Curl (or similar webservice client)

Steps

Listed on the right-hand side of the page are the steps to create a permissioned network.

1. Create folders

Each node requires a data directory for the blockchain data. When the node starts, Besu saves the node key in this directory.

Create directories for your permissioned network, each of the three nodes, and a data directory for each node:

Permissioned-Network/
├── Node-1
│   ├── data
├── Node-2
│   ├── data
└── Node-3
    ├── data

2. Get the address of Node-1

In networks using Clique, you must include the address of at least one initial signer in the genesis file. For this network, we’ll use Node-1 as the initial signer. This requires obtaining the address for Node-1.

To retrieve the address for Node-1, in the Node-1 directory, use the public-key export-address subcommand to write the node address to the specified file (nodeAddress1 in this example).

besu --data-path=data public-key export-address --to=data/nodeAddress1

besu --data-path=data public-key export-address --to=data\nodeAddress1

3. Create the genesis file

The genesis file defines the genesis block of the blockchain (that is, the start of the blockchain). The Clique genesis file includes the address of Node-1 as the initial signer in the extraData field.

All nodes in a network must use the same genesis file.

Copy the following genesis definition to a file called cliqueGenesis.json and save it in the Permissioned-Network directory:

{
  "config":{
    "chainId":1981,
    "constantinoplefixblock": 0,
    "clique":{
      "blockperiodseconds":15,
      "epochlength":30000
    }
  },
  "coinbase":"0x0000000000000000000000000000000000000000",
  "difficulty":"0x1",

"extraData":"0x0000000000000000000000000000000000000000000000000000000000000000<Node 1 Address>0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
  "gasLimit":"0xa00000",
  "mixHash":"0x0000000000000000000000000000000000000000000000000000000000000000",
  "nonce":"0x0",
  "timestamp":"0x5c51a607",
  "alloc": {
      "fe3b557e8fb62b89f4916b721be55ceb828dbd73": {
        "privateKey": "8f2a55949038a9610f50fb23b5883af3b4ecb3c3bb792cbcefbd1542c692be63",
        "comment": "private key and this comment are ignored.  In a real chain, the private key should NOT be stored",
        "balance": "0xad78ebc5ac6200000"
      },
      "627306090abaB3A6e1400e9345bC60c78a8BEf57": {
        "privateKey": "c87509a1c067bbde78beb793e6fa76530b6382a4c0241e5e4a9ec0a0f44dc0d3",
        "comment": "private key and this comment are ignored.  In a real chain, the private key should NOT be stored",
        "balance": "90000000000000000000000"
      },
      "f17f52151EbEF6C7334FAD080c5704D77216b732": {
        "privateKey": "ae6ae8e5ccbfb04590405997ee2d52d2b330726137b875053c36d94e974d162f",
        "comment": "private key and this comment are ignored.  In a real chain, the private key should NOT be stored",
        "balance": "90000000000000000000000"
      }
   },
  "number":"0x0",
  "gasUsed":"0x0",
  "parentHash":"0x0000000000000000000000000000000000000000000000000000000000000000"
}

In extraData, replace <Node 1 Address> with the address for Node-1, excluding the 0x prefix.

Example

{
  ...
"extraData":"0x0000000000000000000000000000000000000000000000000000000000000000b9b81ee349c3807e46bc71aa2632203c5b4620340000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000",
  ...
}

Warning

Do not use the accounts in the genesis file on MainNet or any public network except for testing. The private keys display, which means the accounts are not secure.

4. Create the permissions configuration file

The permissions configuration file defines the nodes and accounts allowlists.

Copy the following permissions configuration to a file called permissions_config.toml and save a copy in the Node-1/data, Node-2/data, and Node-3/data directories:

permissions_config.toml

accounts-allowlist=["0xfe3b557e8fb62b89f4916b721be55ceb828dbd73", "0x627306090abaB3A6e1400e9345bC60c78a8BEf57"]

nodes-allowlist=[]

The permissions configuration file includes the first two accounts from the genesis file.

Use the JSON-RPC API to add permissioned nodes after starting the nodes.

Note

You specify permissions at the node level. Save the [permissions_config.toml] file in the data directory for each node.

5. Start Node-1

Use the following command:

besu --data-path=data --genesis-file=../cliqueGenesis.json --permissions-nodes-config-file-enabled --permissions-accounts-config-file-enabled --rpc-http-enabled --rpc-http-api=ADMIN,ETH,NET,PERM,CLIQUE --host-allowlist="*" --rpc-http-cors-origins="*"

besu --data-path=data --genesis-file=..\cliqueGenesis.json --permissions-nodes-config-file-enabled --permissions-accounts-config-file-enabled --rpc-http-enabled --rpc-http-api=ADMIN,ETH,NET,PERM,CLIQUE --host-allowlist="*" --rpc-http-cors-origins="*"

The command line allows you to enable:

  • Nodes and accounts permissions using the [--permissions-nodes-config-file-enabled] and [--permissions-accounts-config-file-enabled] options
  • The JSON-RPC API using the --rpc-http-enabled option
  • The ADMIN, ETH, NET, PERM, and CLIQUE APIs using the --rpc-http-api option
  • All-host access to the HTTP JSON-RPC API using the --host-allowlist option
  • All-domain access to the node through the HTTP JSON-RPC API using the --rpc-http-cors-origins option.

When the node starts, the enode URL displays. You need the enode URL to specify Node-1 as a peer and update the permissions configuration file in the following steps.

Node 1 Enode URL

6. Start Node-2

Start another terminal, change to the Node-2 directory, and start Node-2:

besu --data-path=data --genesis-file=../cliqueGenesis.json --permissions-nodes-config-file-enabled --permissions-accounts-config-file-enabled --rpc-http-enabled --rpc-http-api=ADMIN,ETH,NET,PERM,CLIQUE --host-allowlist="*" --rpc-http-cors-origins="*" --p2p-port=30304 --rpc-http-port=8546

besu --data-path=data --genesis-file=..\cliqueGenesis.json --permissions-nodes-config-file-enabled --permissions-accounts-config-file-enabled --rpc-http-enabled --rpc-http-api=ADMIN,ETH,NET,PERM,CLIQUE --host-allowlist="*" --rpc-http-cors-origins="*" --p2p-port=30304 --rpc-http-port=8546

The command line specifies:

  • A different port to Node-1 for P2P discovery using the --p2p-port option
  • A different port to Node-1 for HTTP JSON-RPC using the --rpc-http-port option
  • A data directory for Node-2 using the --data-path option
  • Other options as for as for Node-1.

When the node starts, the enode URL is displays. You need the enode URL to update the permissions configuration file in the following steps.

7. Start Node-3

Start another terminal, change to the Node-3 directory, and start Node-3:

besu --data-path=data --genesis-file=../cliqueGenesis.json --permissions-nodes-config-file-enabled --permissions-accounts-config-file-enabled --rpc-http-enabled --rpc-http-api=ADMIN,ETH,NET,PERM,CLIQUE --host-allowlist="*" --rpc-http-cors-origins="*" --p2p-port=30305 --rpc-http-port=8547

besu --data-path=data --genesis-file=..\cliqueGenesis.json --permissions-nodes-config-file-enabled --permissions-accounts-config-file-enabled --rpc-http-enabled --rpc-http-api=ADMIN,ETH,NET,PERM,CLIQUE --host-allowlist="*" --rpc-http-cors-origins="*" --p2p-port=30305 --rpc-http-port=8547

The command line specifies:

  • A different port to Node-1 and Node-2 for P2P discovery using the --p2p-port option
  • A different port to Node-1 and Node-2 for HTTP JSON-RPC using the --rpc-http-port option
  • A data directory for Node-3 using the --data-path option
  • Other options as for as for Node-1.

When the node starts, the enode URL is displays. You need the enode URL to update the permissions configuration file in the following steps.

8. Add enode URLs for nodes to permissions configuration file

Start another terminal and use the perm_addNodesToAllowlist JSON-RPC API method to add the nodes to the permissions configuration file for each node.

Replace <EnodeNode1>, <EnodeNode2>, and <EnodeNode3> with the enode URL displayed when starting each node.

Node-1:

curl -X POST --data '{"jsonrpc":"2.0","method":"perm_addNodesToAllowlist","params":[["<EnodeNode1>","<EnodeNode2>","<EnodeNode3>"]], "id":1}' http://127.0.0.1:8545

Node-2:

curl -X POST --data '{"jsonrpc":"2.0","method":"perm_addNodesToAllowlist","params":[["<EnodeNode1>","<EnodeNode2>","<EnodeNode3>"]], "id":1}' http://127.0.0.1:8546

Node 3:

curl -X POST --data '{"jsonrpc":"2.0","method":"perm_addNodesToAllowlist","params":[["<EnodeNode1>","<EnodeNode2>","<EnodeNode3>"]], "id":1}' http://127.0.0.1:8547

Tip

The cURL call is the same for each node except for the JSON-RPC endpoint.

9. Add nodes as peers

Use the admin_addPeer JSON-RPC API method to add Node-1 as a peer for Node-2 and Node-3.

Replace <EnodeNode1> with the enode URL displayed when starting Node-1.

Node 2:

curl -X POST --data '{"jsonrpc":"2.0","method":"admin_addPeer","params":["<EnodeNode1>"],"id":1}' http://127.0.0.1:8546

Node 3:

curl -X POST --data '{"jsonrpc":"2.0","method":"admin_addPeer","params":["<EnodeNode1>"],"id":1}' http://127.0.0.1:8547

Tip

The cURL call is the same for both nodes except for the JSON-RPC endpoint.

Replace <EnodeNode2> with the enode URL displayed when starting Node-2.

Node 3:

curl -X POST --data '{"jsonrpc":"2.0","method":"admin_addPeer","params":["<EnodeNode2>"],"id":1}' http://127.0.0.1:8547

10. Confirm permissioned network is working

Check peer count

Use cURL to call the JSON-RPC API net_peerCount method and confirm the nodes are functioning as peers:

curl -X POST --data '{"jsonrpc":"2.0","method":"net_peerCount","params":[],"id":1}' localhost:8545

The result confirms Node-1 (the node running the JSON-RPC service) has two peers (Node-2 and Node-3):

{
  "jsonrpc" : "2.0",
  "id" : 1,
  "result" : "0x2"
}

Send a transaction from an account in the allowlist

Import the first account from the genesis file into MetaMask and send transactions, as described in

Account 1

  • Address: 0xfe3b557e8fb62b89f4916b721be55ceb828dbd73
  • Private key : 0x8f2a55949038a9610f50fb23b5883af3b4ecb3c3bb792cbcefbd1542c692be63
  • Initial balance : 0xad78ebc5ac6200000 (200000000000000000000 in decimal)

Info

Besu does not support private key management.

Try sending a transaction from an account not in the accounts allowlist

Import the last account from the genesis file into MetaMask and try to send a transactions, as described in Private Network Example Tutorial:

Account 3

  • Address: 0xf17f52151EbEF6C7334FAD080c5704D77216b732
  • Private key : 0xae6ae8e5ccbfb04590405997ee2d52d2b330726137b875053c36d94e974d162f
  • Initial balance : 0x90000000000000000000000 (2785365088392105618523029504 in decimal)

Start a node not on the nodes allowlist

In your Permissioned-Network directory, create a Node-4 directory and data directory inside it.

Change to the Node-4 directory and start Node-4 specifying the Node-1 enode URL as the bootnode:

besu --data-path=data --bootnodes="<EnodeNode1>" --genesis-file=../cliqueGenesis.json --rpc-http-enabled --rpc-http-api=ADMIN,ETH,NET,PERM,CLIQUE --host-allowlist="*" --rpc-http-cors-origins="*" --p2p-port=30306 --rpc-http-port=8548

besu --data-path=data --bootnodes="<EnodeNode1>" --genesis-file=..\cliqueGenesis.json --rpc-http-enabled --rpc-http-api=ADMIN,ETH,NET,PERM,CLIQUE --host-allowlist="*" --rpc-http-cors-origins="*" --p2p-port=30306 --rpc-http-port=8548

Start another terminal and use cURL to call the JSON-RPC API net_peerCount method:

curl -X POST --data '{"jsonrpc":"2.0","method":"net_peerCount","params":[],"id":1}' localhost:8548

The result confirms Node-4 has no peers even though it specifies Node-1 as a bootnode:

{
  "jsonrpc" : "2.0",
  "id" : 1,
  "result" : "0x0"
}

Stop nodes

When finished using the permissioned network, stop all nodes using Ctrl+C in each terminal window.

Tip

To restart the permissioned network in the future, start from 5. Start Node-1.

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