Account management on ETN-SC

Etn-sc uses an external signer called Clef to manage accounts. This is a standalone piece of software that runs independently of - but connects to - a Etn-sc instance. Clef handles account creation, key management and signing transactions/data. This page explains how to use Clef to create and manage accounts for use with Etn-sc. More information about Clef, including advanced setup options, are available in our dedicated Clef docs.

Initialise Clef

The first time Clef is used it needs to be initialised with a master seed that unlocks Clef’s secure vault and a path where the vault should be located. Clef will use the vault to store passwords for keystores, javascript auto-signing rules and hashes of rule files. To initialise Clef, pass a vault path to clef init, for example to store it in a new directory inside /home/user/eletroneum-sc:

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clef init /home/user/electroneum-sc/clefdata

It is extremely important to remember the master seed and keep it secure. It allows access to the accounts under Clef’s management.

Connecting Etn-sc and Clef

Clef and Etn-sc should be started separately but with complementary configurations so that they can communicate. This requires Clef to know the chain_id of the network Etn-sc will connect to so that this information can be included in any signatures. Clef also needs to know the location of the keystore where accounts are (or will be) stored. This is usually in a subdirectory inside Etn-sc’s data directory. Clef is also given a data directory which is also often placed conveniently inside Etn-sc’s data directory. To enable communication with Clef using Curl, --http can be passed which will start an HTTP server on localhost:8550 by default. To start Clef configured for a Etn-sc node connecting to the testnet:

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clef --chainid 5201420 --keystore ~/.electroneum-sc/testnet/keystore --configdir ~/electroneum-sc/testnet/clef --http

Clef will start running in the terminal, beginning with a disclaimer and a prompt to click “ok”:

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WARNING!

Clef is an account management tool. It may, like any software, contain bugs.

Please take care to
- backup your keystore files,
- verify that the keystore(s) can be opened with your password.

Clef is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY
without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE. See the GNU General Public License for more details.

Enter 'ok' to proceed:
>

Etn-sc can be started in a separate terminal. To connect to Clef, ensure the data directory is consistent with the path provided to Clef and pass the location of the the Clef IPC file - which Clef saves to the path provided to its --configdir flag - in this case we set it to ~/electroneum-sc/testnet/clef:

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etn-sc --testnet --datadir testnet <other flags> --signer=testnet/clef/clef.ipc

Interacting with Clef

There are two modes of interaction with Clef. One is direct interaction, which is achieved by passing requests by HTTP or IPC with JSON-RPC data as defined in Clef’s external API. This is the way to do things in Clef that don’t require Etn-sc, such as creating and listing accounts, or signing data offline. The other way is via Etn-sc. With Etn-sc started with Clef as an external signer, requests made to Etn-sc that touch account data will route via Clef for approval. By default, the user approves or denies interactions manually by typing y or n into the Clef console when prompted, but custom rules can also be created to automate common tasks.

Creating accounts

New accounts can be created using Clef’s account new method. This generates a new key pair and adds them to the given keystore directory:

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clef newaccount --keystore testnet/keystore

Clef will request the new password in the terminal.

The same can be achieved using raw JSON requests (this example send the request to Clef’s exposed HTTP port using curl):

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curl -X POST --data '{"id": 0, "jsonrpc": "2.0", "method": "account_new", "params": []}' http://localhost:8550 -H "Content-Type: application/json"

The console will hang because Clef is waiting for manual approval. Switch to the Clef terminal and approve the action. Clef will prompt for an account password and then confirm the account creation in the terminal logs. A new keyfile has been added to the keystore in electroneum-sc/testnet. A JSON response is returned to the terminal the request originated from, containing the new account address in the result field.

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{"jsonrpc": "2.0", "id": 0, "result": "0x168bc315a2ee09042d83d7c5811b533620531f67"}

It is critical to backup the account password safely and securely as it cannot be retrieved or reset.

If the password provided on account creation is lost or forgotten, there is no way to retrive it and the account will simply stay locked forever. The password MUST be backed up safely and securely! IT IS CRITICAL TO BACKUP THE KEYSTORE AND REMEMBER PASSWORDS!

The newly generated key files can be viewed in <datadir>/keystore/. The file naming format is UTC--<date>--<address> where date is the date and time of key creation formatted according to UTC 8601 with zero time offset and seconds precise to eight decimal places; address is the 40 hexadecimal characters that make up the account address without a leading 0x, for example:

UTC--2022-05-19T12-34-36.47413510Z--0b85e5a13e118466159b1e1b6a4234e5f9f784bb

An account can also be created by importing a raw private key (hex string) using clef importraw as follows:

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clef importraw <hexkey>

The terminal will respond with the following message, indicating the account has been created successfully:

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## Info
Key imported:
  Address 0x9160DC9105f7De5dC5E7f3d97ef11DA47269BdA6
  Keystore file: /home/user/.electroneum-sc/keystore/UTC--2022-10-28T12-03-13.976383602Z--9160dc9105f7de5dc5e7f3d97ef11da47269bda6

The key is now encrypted; losing the password will result in permanently losing
access to the key and all associated funds!

Make sure to backup keystore and passwords in a safe location.

Listing accounts

The accounts in the keystore can be listed to the terminal using a simple CLI command as follows:

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clef list-accounts --keystore <path-to-keystore>

or using account_list in a POST request as follows:

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curl -X POST --data '{"id": 0, "jsonrpc": "2.0", "method": "account_list", "params": []}' http://localhost:8550 -H "Content-Type: application/json"

This returns a JSON object with the account addresses in an array in the result field.

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{"jsonrpc": "2.0", "id": 0, "result": ["0x168bc315a2ee09042d83d7c5811b533620531f67", "0x0b85e5a13e118466159b1e1b6a4234e5f9f784bb"]}

The ordering of accounts when they are listed is lexicographic, but is effectively chronological based on time of creation due to the timestamp in the file name. It is safe to transfer the entire keystore directory or individual key files between Electroneum nodes. This is important because when accounts are added from other nodes the order of accounts in the keystore may change. It is therefore important not to rely on account indexes in scripts or code snippets.

Accounts can also be listed in the Javascript console using eth.accounts, which will defer to Clef for approval.

As well as individual accounts, any wallets managed by Clef can be listed (which will also print the wallet status and the address and URl of any accounts they contain. This uses the list-wallets CLI command.

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clef list-wallets --keystore <path-to-keystore>

which returns:

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- Wallet 0 at keystore:///home/user/Code/electroneum-sc/testnet/keystore/UTC--2022-11-01T17-05-01.517877299Z--4f4094babd1a8c433e0f52a6ee3b6ff32dee6a9c (Locked )
  - Account 0: 0x4f4094BaBd1A8c433e0f52A6ee3B6ff32dEe6a9c (keystore:///home/user/electroneum-sc/testnet/keystore/UTC--2022-11-01T17-05-01.517877299Z--4f4094babd1a8c433e0f52a6ee3b6ff32dee6a9c)
- Wallet 1 at keystore:///home/user/electroneum-sc/testnet/keystore/UTC--2022-11-01T17-05-11.100536003Z--8ef15919f852a8034688a71d8b57ab0187364009 (Locked )
  - Account 0: 0x8Ef15919F852A8034688a71d8b57Ab0187364009 (keystore:///home/user/electroneum-sc/testnet/keystore/UTC--2022-11-01T17-05-11.100536003Z--8ef15919f852a8034688a71d8b57ab0187364009)

Import a keyfile

It is also possible to create an account by importing an existing private key. For example, a user might already have some ETN at an address they created using a browser wallet and now wish to use a new Etn-sc node to interact with their funds. In this case, the private key can be exported from the browser wallet and imported into Etn-sc. It is possible to do this using Clef, but currently the method is not externally exposed and requires implementing a UI. There is a Python UI on the Etn-sc GitHub that could be used as an example or it can be done using the default console UI. However, for now, the most straightforward way to import an account from a private key is to use Etn-sc’s account import.

Etn-sc requires the private key to be stored as a file which contains the private key as unencrypted canonical elliptic curve bytes encoded into hex (i.e. plain text key without leading 0x). The new account is then saved in encrypted format, protected by a passphrase the user provides on request. As always, this passphrase must be securely and safely backed up - there is no way to retrieve or reset it if it is forgotten!

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$ etn-sc account import --datadir /some-dir ./keyfile

The following information will be displayed in the terminal, indicating a successful import:

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Please enter a passphrase now.
Passphrase:
Repeat Passphrase:
Address: {7f444580bfef4b9bc7e14eb7fb2a029336b07c9d}

This import/export process is not necessary for users transferring accounts between Etn-sc instances because the key files can simply be copied directly from one keystore to another.

It is also possible to import an account in non-interactive mode by saving the account password as plaintext in a .txt file and passing its path with the --password flag on startup.

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etn-sc account import --password path/password.txt path/keyfile

In this case, it is important to ensure the password file is not readable by anyone but the intended user. This can be achieved by changing the file permissions. On Linux, the following commands update the file permissions so only the current user has access:

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chmod 700 /path/to/password
cat > /path/to/password
<type password here>

Updating accounts

Clef can be used to set and remove passwords for an existing keystore file. To set a new password, pass the account address to setpw:

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clef setpw a94f5374fce5edbc8e2a8697c15331677e6ebf0b

This will cause Clef to prompt for a new password, twice, and then the Clef master password to decrypt the keyfile.

Etn-sc’s account update subcommand can also be used to update the account password:

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etn-sc account update a94f5374fce5edbc8e2a8697c15331677e6ebf0b

Alternatively, in non-interactive mode the path to a password file containing the account password in unencrypted plaintext can be passed with the --password flag:

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etn-sc account update a94f5374fce5edbc8e2a8697c15331677e6ebf0b --password path/password.txt

Updating the account using etn-sc account update replaces the original file with a new one - this means the original file is no longer available after it has been updated. This can be used to update a key file to the latest format.

Unlocking accounts

With Clef, indiscriminate account unlocking is no longer a feature. Instead, Clef unlocks are locked until actions are explicitly approved manually by a user, unless they conform to some specific scenario that has been encoded in a ruleset. Please refer to our Clef docs for instructions for how to create rulesets.

Transactions

Transactions can be sent using raw JSON requests to Etn-sc or using web3js in the Javascript console. Either way, with Clef acting as the signer the transactions will not get sent until approval is given in Clef. The following code snippet shows how a transaction could be sent between two accounts in the keystore using the Javascript console.

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var tx = {from: eth.accounts[1], to: eth.accounts[2], value: web3.toWei(5, "ether")}

# this will hang until approval is given in the Clef console
eth.sendTransaction(tx)

Summary

This page has demonstrated how to manage accounts using Clef and Etn-sc’s account management tools. Accounts are stored encrypted by a password. It is critical that the account passwords and the keystore directory are safely and securely backed up.