x/auth
Abstract
This document specifies the auth module of the Cosmos SDK.
The auth module is responsible for specifying the base transaction and account types for an application, since the SDK itself is agnostic to these particulars. It contains the middlewares, where all basic transaction validity checks (signatures, nonces, auxiliary fields) are performed, and exposes the account keeper, which allows other modules to read, write, and modify accounts.
This module is used in the Cosmos Hub.
Contents
Concepts
Note: The auth module is different from the authz module.
The differences are:
auth
- authentication of accounts and transactions for Cosmos SDK applications and is responsible for specifying the base transaction and account types.authz
- authorization for accounts to perform actions on behalf of other accounts and enables a granter to grant authorizations to a grantee that allows the grantee to execute messages on behalf of the granter.
Gas & Fees
Fees serve two purposes for an operator of the network.
Fees limit the growth of the state stored by every full node and allow for general purpose censorship of transactions of little economic value. Fees are best suited as an anti-spam mechanism where validators are disinterested in the use of the network and identities of users.
Fees are determined by the gas limits and gas prices transactions provide, where
fees = ceil(gasLimit * gasPrices)
. Txs incur gas costs for all state reads/writes,
signature verification, as well as costs proportional to the tx size. Operators
should set minimum gas prices when starting their nodes. They must set the unit
costs of gas in each token denomination they wish to support:
simd start ... --minimum-gas-prices=0.00001stake;0.05photinos
When adding transactions to mempool or gossipping transactions, validators check if the transaction's gas prices, which are determined by the provided fees, meet any of the validator's minimum gas prices. In other words, a transaction must provide a fee of at least one denomination that matches a validator's minimum gas price.
CometBFT does not currently provide fee based mempool prioritization, and fee based mempool filtering is local to node and not part of consensus. But with minimum gas prices set, such a mechanism could be implemented by node operators.
Because the market value for tokens will fluctuate, validators are expected to dynamically adjust their minimum gas prices to a level that would encourage the use of the network.
State
Accounts
Accounts contain authentication information for a uniquely identified external user of an SDK blockchain,
including public key, address, and account number / sequence number for replay protection. For efficiency,
since account balances must also be fetched to pay fees, account structs also store the balance of a user
as sdk.Coins
.
Accounts are exposed externally as an interface, and stored internally as either a base account or vesting account. Module clients wishing to add more account types may do so.
0x01 | Address -> ProtocolBuffer(account)
Account Interface
The account interface exposes methods to read and write standard account information. Note that all of these methods operate on an account struct conforming to the interface - in order to write the account to the store, the account keeper will need to be used.
// AccountI is an interface used to store coins at a given address within state.
// It presumes a notion of sequence numbers for replay protection,
// a notion of account numbers for replay protection for previously pruned accounts,
// and a pubkey for authentication purposes.
//
// Many complex conditions can be used in the concrete struct which implements AccountI.
type AccountI interface {
proto.Message
GetAddress() sdk.AccAddress
SetAddress(sdk.AccAddress) error // errors if already set.
GetPubKey() crypto.PubKey // can return nil.
SetPubKey(crypto.PubKey) error
GetAccountNumber() uint64
SetAccountNumber(uint64) error
GetSequence() uint64
SetSequence(uint64) error
// Ensure that account implements stringer
String() string
}
Base Account
A base account is the simplest and most common account type, which just stores all requisite fields directly in a struct.
// BaseAccount defines a base account type. It contains all the necessary fields
// for basic account functionality. Any custom account type should extend this
// type for additional functionality (e.g. vesting).
message BaseAccount {
string address = 1;
google.protobuf.Any pub_key = 2;
uint64 account_number = 3;
uint64 sequence = 4;
}
Vesting Account
See Vesting.
AnteHandlers
The x/auth
module presently has no transaction handlers of its own, but does expose the special AnteHandler
, used for performing basic validity checks on a transaction, such that it could be thrown out of the mempool.
The AnteHandler
can be seen as a set of decorators that check transactions within the current context, per ADR 010.
Note that the AnteHandler
is called on both CheckTx
and DeliverTx
, as CometBFT proposers presently have the ability to include in their proposed block transactions which fail CheckTx
.
Decorators
The auth module provides AnteDecorator
s that are recursively chained together into a single AnteHandler
in the following order:
SetUpContextDecorator
: Sets theGasMeter
in theContext
and wraps the nextAnteHandler
with a defer clause to recover from any downstreamOutOfGas
panics in theAnteHandler
chain to return an error with information on gas provided and gas used.RejectExtensionOptionsDecorator
: Rejects all extension options which can optionally be included in protobuf transactions.MempoolFeeDecorator
: Checks if thetx
fee is above local mempoolminFee
parameter duringCheckTx
.ValidateBasicDecorator
: Callstx.ValidateBasic
and returns any non-nil error.TxTimeoutHeightDecorator
: Check for atx
height timeout.ValidateMemoDecorator
: Validatestx
memo with application parameters and returns any non-nil error.ConsumeGasTxSizeDecorator
: Consumes gas proportional to thetx
size based on application parameters.DeductFeeDecorator
: Deducts theFeeAmount
from first signer of thetx
. If thex/feegrant
module is enabled and a fee granter is set, it deducts fees from the fee granter account.SetPubKeyDecorator
: Sets the pubkey from atx
's signers that does not already have its corresponding pubkey saved in the state machine and in the current context.ValidateSigCountDecorator
: Validates the number of signatures intx
based on app-parameters.SigGasConsumeDecorator
: Consumes parameter-defined amount of gas for each signature. This requires pubkeys to be set in context for all signers as part ofSetPubKeyDecorator
.SigVerificationDecorator
: Verifies all signatures are valid. This requires pubkeys to be set in context for all signers as part ofSetPubKeyDecorator
.IncrementSequenceDecorator
: Increments the account sequence for each signer to prevent replay attacks.
Keepers
The auth module only exposes one keeper, the account keeper, which can be used to read and write accounts.
Account Keeper
Presently only one fully-permissioned account keeper is exposed, which has the ability to both read and write all fields of all accounts, and to iterate over all stored accounts.
// AccountKeeperI is the interface contract that x/auth's keeper implements.
type AccountKeeperI interface {
// Return a new account with the next account number and the specified address. Does not save the new account to the store.
NewAccountWithAddress(sdk.Context, sdk.AccAddress) types.AccountI
// Return a new account with the next account number. Does not save the new account to the store.
NewAccount(sdk.Context, types.AccountI) types.AccountI
// Check if an account exists in the store.
HasAccount(sdk.Context, sdk.AccAddress) bool
// Retrieve an account from the store.
GetAccount(sdk.Context, sdk.AccAddress) types.AccountI
// Set an account in the store.
SetAccount(sdk.Context, types.AccountI)
// Remove an account from the store.
RemoveAccount(sdk.Context, types.AccountI)
// Iterate over all accounts, calling the provided function. Stop iteration when it returns true.
IterateAccounts(sdk.Context, func(types.AccountI) bool)
// Fetch the public key of an account at a specified address
GetPubKey(sdk.Context, sdk.AccAddress) (crypto.PubKey, error)
// Fetch the sequence of an account at a specified address.
GetSequence(sdk.Context, sdk.AccAddress) (uint64, error)
// Fetch the next account number, and increment the internal counter.
NextAccountNumber(sdk.Context) uint64
}
Parameters
The auth module contains the following parameters:
Key | Type | Example |
---|---|---|
MaxMemoCharacters | uint64 | 256 |
TxSigLimit | uint64 | 7 |
TxSizeCostPerByte | uint64 | 10 |
SigVerifyCostED25519 | uint64 | 590 |
SigVerifyCostSecp256k1 | uint64 | 1000 |
Client
CLI
A user can query and interact with the auth
module using the CLI.
Query
The query
commands allow users to query auth
state.
simd query auth --help
account
The account
command allow users to query for an account by it's address.
simd query auth account [address] [flags]
Example:
simd query auth account cosmos1...
Example Output:
'@type': /cosmos.auth.v1beta1.BaseAccount
account_number: "0"
address: cosmos1zwg6tpl8aw4rawv8sgag9086lpw5hv33u5ctr2
pub_key:
'@type': /cosmos.crypto.secp256k1.PubKey
key: ApDrE38zZdd7wLmFS9YmqO684y5DG6fjZ4rVeihF/AQD
sequence: "1"
accounts
The accounts
command allow users to query all the available accounts.
simd query auth accounts [flags]
Example:
simd query auth accounts
Example Output:
accounts:
- '@type': /cosmos.auth.v1beta1.BaseAccount
account_number: "0"
address: cosmos1zwg6tpl8aw4rawv8sgag9086lpw5hv33u5ctr2
pub_key:
'@type': /cosmos.crypto.secp256k1.PubKey
key: ApDrE38zZdd7wLmFS9YmqO684y5DG6fjZ4rVeihF/AQD
sequence: "1"
- '@type': /cosmos.auth.v1beta1.ModuleAccount
base_account:
account_number: "8"
address: cosmos1yl6hdjhmkf37639730gffanpzndzdpmhwlkfhr
pub_key: null
sequence: "0"
name: transfer
permissions:
- minter
- burner
- '@type': /cosmos.auth.v1beta1.ModuleAccount
base_account:
account_number: "4"
address: cosmos1fl48vsnmsdzcv85q5d2q4z5ajdha8yu34mf0eh
pub_key: null
sequence: "0"
name: bonded_tokens_pool
permissions:
- burner
- staking
- '@type': /cosmos.auth.v1beta1.ModuleAccount
base_account:
account_number: "5"
address: cosmos1tygms3xhhs3yv487phx3dw4a95jn7t7lpm470r
pub_key: null
sequence: "0"
name: not_bonded_tokens_pool
permissions:
- burner
- staking
- '@type': /cosmos.auth.v1beta1.ModuleAccount
base_account:
account_number: "6"
address: cosmos10d07y265gmmuvt4z0w9aw880jnsr700j6zn9kn
pub_key: null
sequence: "0"
name: gov
permissions:
- burner
- '@type': /cosmos.auth.v1beta1.ModuleAccount
base_account:
account_number: "3"
address: cosmos1jv65s3grqf6v6jl3dp4t6c9t9rk99cd88lyufl
pub_key: null
sequence: "0"
name: distribution
permissions: []
- '@type': /cosmos.auth.v1beta1.BaseAccount
account_number: "1"
address: cosmos147k3r7v2tvwqhcmaxcfql7j8rmkrlsemxshd3j
pub_key: null
sequence: "0"
- '@type': /cosmos.auth.v1beta1.ModuleAccount
base_account:
account_number: "7"
address: cosmos1m3h30wlvsf8llruxtpukdvsy0km2kum8g38c8q
pub_key: null
sequence: "0"
name: mint
permissions:
- minter
- '@type': /cosmos.auth.v1beta1.ModuleAccount
base_account:
account_number: "2"
address: cosmos17xpfvakm2amg962yls6f84z3kell8c5lserqta
pub_key: null
sequence: "0"
name: fee_collector
permissions: []
pagination:
next_key: null
total: "0"
params
The params
command allow users to query the current auth parameters.
simd query auth params [flags]
Example:
simd query auth params
Example Output:
max_memo_characters: "256"
sig_verify_cost_ed25519: "590"
sig_verify_cost_secp256k1: "1000"
tx_sig_limit: "7"
tx_size_cost_per_byte: "10"
Transactions
The auth
module supports transactions commands to help you with signing and more. Compared to other modules you can access directly the auth
module transactions commands using the only tx
command.
Use directly the --help
flag to get more information about the tx
command.
simd tx --help
sign
The sign
command allows users to sign transactions that was generated offline.
simd tx sign tx.json --from $ALICE > tx.signed.json
The result is a signed transaction that can be broadcasted to the network thanks to the broadcast command.
More information about the sign
command can be found running simd tx sign --help
.
sign-batch
The sign-batch
command allows users to sign multiples offline generated transactions.
The transactions can be in one file, with one tx per line, or in multiple files.
simd tx sign txs.json --from $ALICE > tx.signed.json
or
simd tx sign tx1.json tx2.json tx3.json --from $ALICE > tx.signed.json
The result is multiples signed transactions. For combining the signed transactions into one transactions, use the --append
flag.
More information about the sign-batch
command can be found running simd tx sign-batch --help
.
multi-sign
The multi-sign
command allows users to sign transactions that was generated offline by a multisig account.
simd tx multi-sign transaction.json k1k2k3 k1sig.json k2sig.json k3sig.json
Where k1k2k3
is the multisig account address, k1sig.json
is the signature of the first signer, k2sig.json
is the signature of the second signer, and k3sig.json
is the signature of the third signer.
Nested multisig transactions
To allow transactions to be signed by nested multisigs, meaning that a participant of a multisig account can be another multisig account, the --skip-signature-verification
flag must be used.
# First aggregate signatures of the multisig participant
simd tx multi-sign transaction.json ms1 ms1p1sig.json ms1p2sig.json --signature-only --skip-signature-verification > ms1sig.json
# Then use the aggregated signatures and the other signatures to sign the final transaction
simd tx multi-sign transaction.json k1ms1 k1sig.json ms1sig.json --skip-signature-verification
Where ms1
is the nested multisig account address, ms1p1sig.json
is the signature of the first participant of the nested multisig account, ms1p2sig.json
is the signature of the second participant of the nested multisig account, and ms1sig.json
is the aggregated signature of the nested multisig account.
k1ms1
is a multisig account comprised of an individual signer and another nested multisig account (ms1
). k1sig.json
is the signature of the first signer of the individual member.
More information about the multi-sign
command can be found running simd tx multi-sign --help
.
multisign-batch
The multisign-batch
works the same way as sign-batch
, but for multisig accounts.
With the difference that the multisign-batch
command requires all transactions to be in one file, and the --append
flag does not exist.
More information about the multisign-batch
command can be found running simd tx multisign-batch --help
.
validate-signatures
The validate-signatures
command allows users to validate the signatures of a signed transaction.
$ simd tx validate-signatures tx.signed.json
Signers:
0: cosmos1l6vsqhh7rnwsyr2kyz3jjg3qduaz8gwgyl8275
Signatures:
0: cosmos1l6vsqhh7rnwsyr2kyz3jjg3qduaz8gwgyl8275 [OK]
More information about the validate-signatures
command can be found running simd tx validate-signatures --help
.
broadcast
The broadcast
command allows users to broadcast a signed transaction to the network.
simd tx broadcast tx.signed.json
More information about the broadcast
command can be found running simd tx broadcast --help
.
gRPC
A user can query the auth
module using gRPC endpoints.
Account
The account
endpoint allow users to query for an account by it's address.
cosmos.auth.v1beta1.Query/Account
Example:
grpcurl -plaintext \
-d '{"address":"cosmos1.."}' \
localhost:9090 \
cosmos.auth.v1beta1.Query/Account
Example Output:
{
"account":{
"@type":"/cosmos.auth.v1beta1.BaseAccount",
"address":"cosmos1zwg6tpl8aw4rawv8sgag9086lpw5hv33u5ctr2",
"pubKey":{
"@type":"/cosmos.crypto.secp256k1.PubKey",
"key":"ApDrE38zZdd7wLmFS9YmqO684y5DG6fjZ4rVeihF/AQD"
},
"sequence":"1"
}
}
Accounts
The accounts
endpoint allow users to query all the available accounts.
cosmos.auth.v1beta1.Query/Accounts
Example:
grpcurl -plaintext \
localhost:9090 \
cosmos.auth.v1beta1.Query/Accounts
Example Output:
{
"accounts":[
{
"@type":"/cosmos.auth.v1beta1.BaseAccount",
"address":"cosmos1zwg6tpl8aw4rawv8sgag9086lpw5hv33u5ctr2",
"pubKey":{
"@type":"/cosmos.crypto.secp256k1.PubKey",
"key":"ApDrE38zZdd7wLmFS9YmqO684y5DG6fjZ4rVeihF/AQD"
},
"sequence":"1"
},
{
"@type":"/cosmos.auth.v1beta1.ModuleAccount",
"baseAccount":{
"address":"cosmos1yl6hdjhmkf37639730gffanpzndzdpmhwlkfhr",
"accountNumber":"8"
},
"name":"transfer",
"permissions":[
"minter",
"burner"
]
},
{
"@type":"/cosmos.auth.v1beta1.ModuleAccount",
"baseAccount":{
"address":"cosmos1fl48vsnmsdzcv85q5d2q4z5ajdha8yu34mf0eh",
"accountNumber":"4"
},
"name":"bonded_tokens_pool",
"permissions":[
"burner",
"staking"
]
},
{
"@type":"/cosmos.auth.v1beta1.ModuleAccount",
"baseAccount":{
"address":"cosmos1tygms3xhhs3yv487phx3dw4a95jn7t7lpm470r",
"accountNumber":"5"
},
"name":"not_bonded_tokens_pool",
"permissions":[
"burner",
"staking"
]
},
{
"@type":"/cosmos.auth.v1beta1.ModuleAccount",
"baseAccount":{
"address":"cosmos10d07y265gmmuvt4z0w9aw880jnsr700j6zn9kn",
"accountNumber":"6"
},
"name":"gov",
"permissions":[
"burner"
]
},
{
"@type":"/cosmos.auth.v1beta1.ModuleAccount",
"baseAccount":{
"address":"cosmos1jv65s3grqf6v6jl3dp4t6c9t9rk99cd88lyufl",
"accountNumber":"3"
},
"name":"distribution"
},
{
"@type":"/cosmos.auth.v1beta1.BaseAccount",
"accountNumber":"1",
"address":"cosmos147k3r7v2tvwqhcmaxcfql7j8rmkrlsemxshd3j"
},
{
"@type":"/cosmos.auth.v1beta1.ModuleAccount",
"baseAccount":{
"address":"cosmos1m3h30wlvsf8llruxtpukdvsy0km2kum8g38c8q",
"accountNumber":"7"
},
"name":"mint",
"permissions":[
"minter"
]
},
{
"@type":"/cosmos.auth.v1beta1.ModuleAccount",
"baseAccount":{
"address":"cosmos17xpfvakm2amg962yls6f84z3kell8c5lserqta",
"accountNumber":"2"
},
"name":"fee_collector"
}
],
"pagination":{
"total":"9"
}
}
Params
The params
endpoint allow users to query the current auth parameters.
cosmos.auth.v1beta1.Query/Params
Example:
grpcurl -plaintext \
localhost:9090 \
cosmos.auth.v1beta1.Query/Params
Example Output:
{
"params": {
"maxMemoCharacters": "256",
"txSigLimit": "7",
"txSizeCostPerByte": "10",
"sigVerifyCostEd25519": "590",
"sigVerifyCostSecp256k1": "1000"
}
}
REST
A user can query the auth
module using REST endpoints.
Account
The account
endpoint allow users to query for an account by it's address.
/cosmos/auth/v1beta1/account?address={address}
Accounts
The accounts
endpoint allow users to query all the available accounts.
/cosmos/auth/v1beta1/accounts
Params
The params
endpoint allow users to query the current auth parameters.
/cosmos/auth/v1beta1/params