13 KiB
| title | sort_key |
|---|---|
| Account Management | C |
The recommended practise for managing accounts in Geth is to use Clef. However, Geth also has its own, convenient account management tools. Eventually, these built in tools will be deprecated in favour of using Clef as the default account manager. This page describes account management using Geth's built-in tools. It is recommended to also visit the following pages that explain how to use Clef.
Account command
Geth's account command is used to interact with accounts:
geth account <command> [options...] [arguments...]
The account command enables the user to create new accounts, list existing
accounts, import private keys into a new account, update key formats and update
the passwords that lock each account. In interactive mode, the user is prompted
for passwords in the console when the account functions are invoked, whereas
in non-interactive mode passwords to unlock accounts are saved to text files
whose path is passed to Geth at startup. Non-interactive mode is only intended
for use on private networks or known safe environments.
The account subcommands are:
COMMANDS:
list Print summary of existing accounts
new Create a new account
update Update an existing account
import Import a private key into a new account
Information about the subcommands can be displayed in the terminal using
geth account <command> --help. For example, for the list subcommand:
$ geth account list --help
list [command options] [arguments...]
Print a short summary of all accounts
OPTIONS:
--datadir "/home/.ethereum" Data directory for the databases and keystore
--keystore Directory for the keystore (default = inside the datadir)
Creating new accounts
New accounts can be created using account new. This generates a new key
pair and adds them to the keystore directory in the datadir. To
create a new account in the default data directory:
$ geth account new
This returns the following to the terminal:
Your new account is locked with a password. Please give a password. Do not forget this password.
Passphrase:
Repeat Passphrase:
Address: {168bc315a2ee09042d83d7c5811b533620531f67}
It is critical to backup the account password safely and securely as it cannot be retrieved or reset.
{% include note.html content=" 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
Listing Accounts
Listing all existing accounts is achieved using the account list command. If the
keystore is located anywhere other than the default location its path should be
included with the keystore flag. For example, if the datadir is some-dir:
geth account list --keystore some-dir/keystore
This command returns the following to the terminal for a keystore with two files:
Account 0: {5afdd78bdacb56ab1dad28741ea2a0e47fe41331} keystore:///tmp/mykeystore/UTC--2017-04-28T08-46-27.437847599Z--5afdd78bdacb56ab1dad28741ea2a0e47fe41331
Account 1: {9acb9ff906641a434803efb474c96a837756287f} keystore:///tmp/mykeystore/UTC--2017-04-28T08-46-52.180688336Z--9acb9ff906641a434803efb474c96a837756287f
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
Ethereum 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.
Importing accounts
Import a keyfile
It is also possible to create a new account by importing a private key. For example, a user might already have some ether at an address they created using a browser wallet and now wish to use a new Geth node to interact with their funds. In this case, the private key can be exported from the browser wallet and imported into Geth. Geth 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!
$ geth account import --datadir /some-dir ./keyfile
The following information will be displayed in the terminal, indicating a successful import:
Please enter a passphrase now.
Passphrase:
Repeat Passphrase:
Address: {7f444580bfef4b9bc7e14eb7fb2a029336b07c9d}
This import/export process is not necessary for transferring accounts between Geth 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.
geth 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:
chmod 700 /path/to/password
cat > /path/to/password
<type password here>
Import a presale wallet
Assuming the password is known, importing a presale wallet is very easy. The wallet import
commands are used, passing the path to the wallet.
geth wallet import /path/presale.wallet
Updating accounts
The account update subcommand is used to unlock an account and migrate it to the newest
format. This is useful for accounts that may have been created in a format that has since
been deprecated. The same command can be used to update the account password. The current
password and account address are needed in order to update the account, as follows:
geth account update a94f5374fce5edbc8e2a8697c15331677e6ebf0b
The following will be returned to the terminal:
Unlocking account a94f5374fce5edbc8e2a8697c15331677e6ebf0b | Attempt 1/3
Passphrase:
0xa94f5374fce5edbc8e2a8697c15331677e6ebf0b
Account 'a94f5374fce5edbc8e2a8697c15331677e6ebf0b' unlocked.
Please give a new password. Do not forget this password.
Passphrase:
Repeat Passphrase:
0xa94f5374fce5edbc8e2a8697c15331677e6ebf0b
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:
geth account update a94f5374fce5edbc8e2a8697c15331677e6ebf0b --password path/password.txt
Updating the account replaces the original file with a new one - this means the original file is no longer available after it has been updated.
Unlocking accounts
In Geth, accounts are locked unless they are explicitly unlocked. If an account is intended
to be used by apps connecting to Geth via RPC then it can be unlocked in non-interactive
mode by passing the --unlock flag with a comma-separated list of account addresses
(or keystore indexes) to unlock. This unlocks the accounts for one session only. Including
the --unlock flag without any account addresses defaults to unlocking the first account
in the keystore.
geth <other commands> --unlock 0xa94f5374fce5edbc8e2a8697c15331677e6ebf0b
Geth will start and prompt the user to input the account password in the terminal.
Alternatively, the user can provide a password as a text file and pass its path to --password:
geth <other commands> --unlock 0xa94f5374fce5edbc8e2a8697c15331677e6ebf0b --password path/password.txt
{% include note.html content=" By default,
account unlocking is forbidden when HTTP or Websocket access is enabled (i.e. by
passing --http or ws flag). This is because an attacker that manages to access
the node via the externally-exposed HTTP/WS port can then control the unlocked account.
It is possible to force account unlock by including the --allow-insecure-unlock
flag but this is unsafe and not recommended except for expert users that completely
understand how it can be used safely. This is not a hypothetical risk:
there are bots that continually scan for http-enabled Ethereum nodes to attack" %}
Accounts in the Javascript console
Account management can also be achieved in the Javascript console attached to a
running Geth instance. Assuming Geth is already running, in a new terminal attach
a Javascript console using the geth.ipc file. This file can be found in the data
directory. Assuming the data directory is named data the console can be started using:
geth attach data/geth.ipc
New accounts
New accounts can be generated using the Javascript console using personal.newAccount().
A new password is requested in the console and successful account creation is confirmed
by the new account address being displayed.
personal.newAccount()
Accounts can also be created by importing private keys directly in the Javascript console.
The private key is passed as an unencrypted hex-encoded string to personal.importRawKey()
along with a passphrase that will be used to encrypt the key. A new key file will be
generated from the private key and saved to the keystore.
personal.importRawKey("hexstringkey", "password")
Listing accounts
The accounts function in the eth namespace can be used to list the accounts that
currently exist in the keystore.:
eth.accounts
or alternatively the same is achieved using:
personal.listAccounts
This returns an array of account addresses to the terminal.
Unlocking accounts
To unlock an account, the personal.unlockAccount function can be used:
personal.unlockAccount(eth.accounts[1])
The account passphrase is requested:
Unlock account 0xa94f5374fce5edbc8e2a8697c15331677e6ebf0b
Passphrase:
true
This unlocked account can now be used to sign and send transactions. it is also possible to
pass the passphrase as an argument to personal.unlockAccount() along with a duration
after which the accout will automatically re-lock (in seconds), as follows:
personal.unlockAccount(eth.accounts[1], "passphrase", 60)
This unlocks the account for 60 seconds. However, this is not recommended because the
command history is logged by the Javascript console which could compromise the security
of the account. An unlocked account can be manually re-locked using personal.lockAccount(),
passing the address as the sole argument.
Unlocking for transactions
Sending transactions from the Javascript console also requires the sender account to be
unlocked. There are two ways to send transactions: eth.sendTransaction and personal.sendTransaction.
The difference between these two functions is that eth.sendTransaction requires the account to be
unlocked globally, at the node level (i.e., by unlocking it on the command line at the start of
the Geth session). On the other hand, personal.sendTransaction takes a passphrase argument
that unlocks the account temporarily in order to sign the transaction, then locks it again
immediately afterwards. For example, to send 5 ether between two accounts in the keystore:
var tx = {from: eth.accounts[1], to: eth.accounts[2], value: web3.toWei(5, "ether")}
# this requires global account unlock for eth.accounts[1]
eth.sendTransaction(tx)
# this unlocks eth.accounts[1] temporarily just to send the transaction
personal.sendTransaction(tx, "password")
Summary
This page has demonstrated how to use Geth's built-in account management tools, both on the command line and in the Javascript console. Accounts are stored encrypted by a password. It is critical that the account passwords and the keystore directory are safely and securely backed up.