How to run a Symbol node with added security.
The Running a node guide explains how to easily create a node using Symbol Bootstrap. In that guide, the setup process is conducted on the same machine that will host the node, meaning that private keys are generated on a machine connected to the Internet. If you need a hardened level of security you can follow this guide instead, at the cost of a more involved setup process.
The summary of it is that the symbol-bootstrap start command is split into a config phase run offline, which generates a configuration folder, and the rest of the start command is then run on the destination online machine that will host the node. The main account’s private key never leaves the offline machine.
Machine |
Function |
|---|---|
Configuration |
|
Node |
|
A node can also be setup in such a way that all harvesting rewards go to an external account without requiring this account’s private key. This is known as a non-custodial setup and must be configured once the node is up and running, so a pointer to the appropriate guide is given at the end of this page.
On the Configuration machine, while still online:
Install Symbol Bootstrap as instructed in the Using Symbol Bootstrap guide. Make sure you read also the Configuration section of that guide to get acquainted with presets and assemblies.
Install Symbol CLI as instructed in the symbol-cli guide. You just need to run:
npm install --global symbol-cli
Run Symbol Bootstrap a first time, so that it can download the required Docker images:
symbol-bootstrap config -p mainnet -a <assembly> --noPassword
rm -rf target
The output of this first run is irrelevant, that’s why --noPassword is used and the target folder is removed.
Disconnect the Configuration machine from the Internet since private keys will be generated on this machine from this point.
Create the main account profile. This is the account that will receive all harvesting fees and whose importance score will be used when harvesting.
The purpose of this guide is making sure that this account’s private key is never used on an online machine.
This step will create a symbol-cli profile to hold the main account and sign transactions using its private key. The machine is offline now, so you need to provide some network-related data.
Note
The commands below assume you want to create a new main account and use the profile create command. If you already have an account that you would like to use as main use the profile import command instead.
symbol-cli profile create --profile offline-main --default \
--url http://localhost:3000 --network MAIN_NET \
--generation-hash 57F7DA205008026C776CB6AED843393F04CD458E0AA2D9F1D5F31A402072B2D6 \
--namespace-id symbol.xym --divisibility 6 \
--epoch-adjustment 1615853185
symbol-cli profile create --profile offline-test --default \
--url http://localhost:3000 --network TEST_NET \
--generation-hash 3B5E1FA6445653C971A50687E75E6D09FB30481055E3990C84B25E9222DC1155 \
--namespace-id symbol.xym --divisibility 6 \
--epoch-adjustment 1616694977
When prompted, enter a password to secure your profile and select the PrivateKey import type:
✔ Enter your wallet password: … *********
✔ Select an import type: › PrivateKey
Account
┌───────────────┬──────────────────────────────────────────────────────────────────────┐
│ Property │ Value │
├───────────────┼──────────────────────────────────────────────────────────────────────┤
│ Address │ NCCE5O-BMZHWM-IYZKR6-4WZKFD-4P7DTS-IRXJZ2-3LI │
├───────────────┼──────────────────────────────────────────────────────────────────────┤
│ Public Key │ 51C2CB98B61D666A993FA9B25EEBCB48DE5F0B1B7D8B79ECB7AFCB1E5E601108 │
├───────────────┼──────────────────────────────────────────────────────────────────────┤
│ Private Key │ ●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●● │
├───────────────┼──────────────────────────────────────────────────────────────────────┤
│ Password │ ●●●●●●●●● │
└───────────────┴──────────────────────────────────────────────────────────────────────┘
SUCCESS Stored offline-main profile
symbol-cli is now ready to be used later on. All transactions will be signed by your main account so make sure it has some funds to pay for the Fees.
Take note of the main account’s private key and keep it in a safe place.
Create a custom preset file for Symbol Bootstrap and name it custom.yml. It must include, at least, these lines:
privateKeySecurityMode: PROMPT_MAIN
nodes:
-
mainPrivateKey: ●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●
You can read more about these properties in the security mode section in Symbol Bootstrap’s documentation.
If you have customizations to make, like enabling voting, you can provide them too:
privateKeySecurityMode: PROMPT_MAIN
nodes:
-
mainPrivateKey: ●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●
voting: true
host: my-symbol-node.com # Could also be an IP address
Run Symbol Bootstrap again, this time with all required parameters:
symbol-bootstrap config -p mainnet -a <assembly> -c custom.yml
You will be asked for the password to use to encrypt the configuration files.
? Enter password to use to encrypt and decrypt custom presets, addresses.yml,
and preset.yml files. When providing a password, private keys will be
encrypted. Keep this password in a secure place! ******
info Password has been provided
info Generating config from preset testnet
info Assembly preset dual
info Generating Main account...
info Generating Transport account...
info Generating Remote account...
info Generating VRF account...
info User for docker resolved: 1000:1000
info Running image using Exec: symbolplatform/symbol-server:tools-gcc-0.10.1.8 bash createNodeCertificates.sh
info Certificate for node api-node created
info Generating api-node server configuration
info Generating api-broker broker configuration
info Non-voting node api-node.
info Configuration generated.
This generates a target directory containing an addresses.yml file and multiple configuration files.
The main account’s private key is not present in any of these files.
It is worth noting that Symbol Bootstrap enables Remote harvesting by default, meaning that the main private key is never available in a plain text file in the client. Only the remote key is, which acts as a proxy between the node and its main account.
Open custom.yml and remove the line containing mainPrivateKey.
Now that Symbol Bootstrap has already used it in the config stage, there is no need for such a sensitive key to be lying around in a plain text file.
Copy the whole target directory to a pen drive (or other non-networked support) to be used later.
Still in the offline Configuration machine, you are now going to prepare a series of link transactions manually. These transactions will be created by symbol-cli, signed by your main account, and will be moved to an online machine to be announced later on.
The following commands all use --max-fee 1000000 which means that 1 XYM will be paid for each transaction. Feel free to use a different number after reading the fees documentation.
Concerning deadlines
All transactions have a deadline, meaning that they must be announced (and confirmed) before the deadline expires.
There is currently a limitation in symbol-cli which sets this deadline to 2 hours after transaction creation, for all non-multisig transactions.
Obtain the AccountKeyLinkTransaction payload.
This links your main account to the remote account used for Remote harvesting. Symbol Bootstrap generated this account for you, and you can find its public key in the target/addresses.yml file:
remote:
publicKey: 1544FE6F504A8B8536C2407664916AFB5C917400FD1B941B981933CDFE52AE3F
In the --linked-public-key parameter below, use the remote account public key:
symbol-cli transaction accountkeylink --max-fee 1000000 --mode normal \
--linked-public-key 1544FE6F504A8B8536C2407664916AFB5C917400FD1B941B981933CDFE52AE3F \
--action Link
Enter the password you used when you created the symbol-cli profile and do not announce the transaction (the machine is offline).
✔ Enter your wallet password: … *********
┌──────────────────────────────────────────────────────────────────────────────────┐
│ ACCOUNT_KEY_LINK │
├───────────────┬──────────────────────────────────────────────────────────────────┤
│ Max fee: │ 1,000,000 │
├───────────────┼──────────────────────────────────────────────────────────────────┤
│ Network type: │ TEST_NET │
├───────────────┼──────────────────────────────────────────────────────────────────┤
│ Deadline: │ 2021-03-27 10:41:41.286 │
├───────────────┼──────────────────────────────────────────────────────────────────┤
│ Action: │ Link │
├───────────────┼──────────────────────────────────────────────────────────────────┤
│ Linked key: │ 1544FE6F504A8B8536C2407664916AFB5C917400FD1B941B981933CDFE52AE3F │
├───────────────┴──────────────────────────────────────────────────────────────────┤
│ Signature details │
├───────────────┬──────────────────────────────────────────────────────────────────┤
│ Payload: │ A10000000000000042E0E0A0B8D7E1F27805F3537F80BFEAB6FEAC318908C486 │
│ │ 4D03260B83ED1D0332D6EA6E086A4B68C578DB690D78D50BDA5C706B1DC66472 │
│ │ 9326511547E42E0FCC6D13D64FB9BF69B72846C3FE99127D48C3293F473D528F │
│ │ B902600CB7DA10330000000001984C4140420F000000000026F54C1B0A000000 │
│ │ 1544FE6F504A8B8536C2407664916AFB5C917400FD1B941B981933CDFE52AE3F │
│ │ 01 │
├───────────────┼──────────────────────────────────────────────────────────────────┤
│ Hash: │ 08C63D3AFAC3767F43053AFF1ACA61381FE81929B2384B91C450010A547AFA4A │
├───────────────┼──────────────────────────────────────────────────────────────────┤
│ Signer: │ CC6D13D64FB9BF69B72846C3FE99127D48C3293F473D528FB902600CB7DA1033 │
└───────────────┴──────────────────────────────────────────────────────────────────┘
✔ Do you want to announce this transaction? … no
Select all the text in the Payload box and paste it into a new text file named payloads.txt. Remove all spaces and other decorations to obtain a single line containing only numbers and uppercase letters:
A100000000000000703C88DEDC4ABC2917F00ADB12C45F2C333B1113405C3CFAB289E78D9C54DDFCB1FE7C3048B6DA735568A935C6C08AF7E70AEC614A2EE9590967A7A044E52B0DCC6D13D64FB9BF69B72846C3FE99127D48C3293F473D528FB902600CB7DA10330000000001984C4140420F000000000038F32C1B0A0000001544FE6F504A8B8536C2407664916AFB5C917400FD1B941B981933CDFE52AE3F01
Obtain the VrfKeyLinkTransaction payload.
This key is required for harvesting.
Again, Symbol Bootstrap has already generated this key for you and you can find it in the target/addresses.yml file:
vrf:
publicKey: 856B6CCA574508158D66046CACEA2D81CB626DEEFDD3B6C466514CE31F32A52B
Use the VRF account public key in the --linked-public-key parameter below and do not announce the transaction (the machine is offline):
symbol-cli transaction vrfkeylink --max-fee 1000000 --mode normal \
--linked-public-key 856B6CCA574508158D66046CACEA2D81CB626DEEFDD3B6C466514CE31F32A52B \
--action Link
Again, copy the content of the Payload box, trim it, and add it to payloads.txt, in a new line.
Obtain the VotingKeyLinkTransaction payload.
This key is only required for voting nodes.
If you added voting: true to custom.yml when creating the configuration, then Symbol Bootstrap has created this key too in target/addresses.yml:
voting:
publicKey: 05693B4300ABFD28CD6BA434DD26F9FAF2342927FE32840898DCB895B8A17E84
Use the Voting account public key in the --linked-public-key parameter below and do not announce the transaction (the machine is offline):
symbol-cli transaction votingkeylink --max-fee 1000000 --mode normal \
--linked-public-key 05693B4300ABFD28CD6BA434DD26F9FAF2342927FE32840898DCB895B8A17E84 \
--action Link --start-point 1 --end-point 360
Again, copy the content of the Payload box, trim it, and add it to payloads.txt, in a new line.
Move now to the online machine, the one that is permanently connected to the Internet and will host the node. Plug in the pen drive with the node configuration.
Install Symbol Bootstrap as instructed in the Using Symbol Bootstrap guide.
Install Symbol CLI as instructed in the symbol-cli guide. You just need to run:
npm install --global symbol-cli
Create an announcer profile for symbol-cli. This is only a temporary account used to announce the payloads; it does not require funds:
Use the --url parameter to specify the NODE_URL to access the network.
symbol-cli profile create --profile announcer --default \
--network MAIN_NET \
--url <NODE_URL>
symbol-cli profile create --profile announcer --default \
--network TEST_NET \
--url <TESTNET_NODE_URL>
When prompted, enter a password to secure your profile, and select the PrivateKey import type:
✔ Enter your wallet password: ... *********
✔ Select an import type: » PrivateKey
...
SUCCESS Stored announcer profile
You will now use symbol-cli to announce to the network the transactions you prepared in payloads.txt.
Announce the Remote key link:
symbol-cli transaction payload --sync --announce
✔ Enter the transaction payload:
Paste the first long text line from payloads.txt and press Enter:
SUCCESS Transaction loaded:
┌──────────────────────────────────────────────────────────────────────────────────┐
│ ACCOUNT_KEY_LINK │
├───────────────┬──────────────────────────────────────────────────────────────────┤
│ Max fee: │ 1,000,000 │
├───────────────┼──────────────────────────────────────────────────────────────────┤
│ Network type: │ TEST_NET │
├───────────────┼──────────────────────────────────────────────────────────────────┤
│ Deadline: │ 2021-03-27 10:41:41.286 │
├───────────────┼──────────────────────────────────────────────────────────────────┤
│ Signer: │ TBGPYD-CO35V2-AMOYEJ-LEM44H-372M3I-6RWVFY-QCY │
├───────────────┼──────────────────────────────────────────────────────────────────┤
│ Action: │ Link │
├───────────────┼──────────────────────────────────────────────────────────────────┤
│ Linked key: │ 1544FE6F504A8B8536C2407664916AFB5C917400FD1B941B981933CDFE52AE3F │
└───────────────┴──────────────────────────────────────────────────────────────────┘
┌──────────────────────────────────────────────────────────────────────────────────┐
│ ACCOUNT_KEY_LINK │
├───────────────┬──────────────────────────────────────────────────────────────────┤
│ Max fee: │ 1,000,000 │
├───────────────┼──────────────────────────────────────────────────────────────────┤
│ Network type: │ TEST_NET │
├───────────────┼──────────────────────────────────────────────────────────────────┤
│ Deadline: │ 2021-03-27 10:41:41.286 │
├───────────────┼──────────────────────────────────────────────────────────────────┤
│ Signer: │ CC6D13D64FB9BF69B72846C3FE99127D48C3293F473D528FB902600CB7DA1033 │
├───────────────┼──────────────────────────────────────────────────────────────────┤
│ Action: │ Link │
├───────────────┼──────────────────────────────────────────────────────────────────┤
│ Linked key: │ 1544FE6F504A8B8536C2407664916AFB5C917400FD1B941B981933CDFE52AE3F │
├───────────────┴──────────────────────────────────────────────────────────────────┤
│ Signature details │
├───────────────┬──────────────────────────────────────────────────────────────────┤
│ Payload: │ A10000000000000042E0E0A0B8D7E1F27805F3537F80BFEAB6FEAC318908C486 │
│ │ 4D03260B83ED1D0332D6EA6E086A4B68C578DB690D78D50BDA5C706B1DC66472 │
│ │ 9326511547E42E0FCC6D13D64FB9BF69B72846C3FE99127D48C3293F473D528F │
│ │ B902600CB7DA10330000000001984C4140420F000000000026F54C1B0A000000 │
│ │ 1544FE6F504A8B8536C2407664916AFB5C917400FD1B941B981933CDFE52AE3F │
│ │ 01 │
├───────────────┼──────────────────────────────────────────────────────────────────┤
│ Hash: │ 08C63D3AFAC3767F43053AFF1ACA61381FE81929B2384B91C450010A547AFA4A │
└───────────────┴──────────────────────────────────────────────────────────────────┘
...
SUCCESS Transaction announced
SUCCESS Transaction confirmed
Note
If the transaction is announced but it never gets confirmed (symbol-cli is stuck in Processing for more than a minute) it can be due to a number of things. Without interrupting symbol-cli, copy the transaction hash, open a new terminal and run:
symbol-cli transaction status --hash <transaction hash>
If there has been any issue with the transaction, this should give you the cause and you can then interrupt symbol-cli.
If you need to try again, never re-announce the same payload. Create a new one (from the Configuration machine) and announce it again.
The most common problems are:
Not enough funds (Failure_Core_Insufficient_Balance): The main account (which signed the transaction) does not have enough funds to pay the fee. Transfer some funds and try with a new payload.
Deadline expired (Failure_Core_Past_Deadline): Create a new payload and announce it again before the deadline expires (See the Concerning deadlines box above).
Insufficient fee: No error will be reported but if the fee is too low most nodes will ignore it. Try again with a higher fee or be ready to wait for a long time.
Payload re-announced: symbol-cli will be stuck in Processing and you will get no relevant information from the transaction status. Just don’t announce the same payload more than once.
If all key link transactions were confirmed the node is now configured and you can finally launch it.
Go to the directory containing the target directory copied from the Configuration machine and start the node:
symbol-bootstrap start
No other parameters are required, the configuration is already present in the target directory and Symbol Bootstrap will use it.
The node should start and a lot of debug output should appear on the screen.
info Password has been provided
info The generated preset target/preset.yml already exist, ignoring configuration. (run -r to reset or --upgrade to upgrade)
...
Your node should now be up and running and its main private key has never left the configuration (offline) machine.
For added security, you can now turn the node’s main account into a Multisig Account. This is useful, for example, for service providers that work in a non-custodial manner. Read about this process in the Non-custodial node setup guide.
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