feat(gentx): allow custom tx validation (#12956)

## Description

Closes: #12833



---

### Author Checklist

*All items are required. Please add a note to the item if the item is not applicable and
please add links to any relevant follow up issues.*

I have...

- [ ] included the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [ ] added `!` to the type prefix if API or client breaking change
- [ ] targeted the correct branch (see [PR Targeting](https://github.com/cosmos/cosmos-sdk/blob/main/CONTRIBUTING.md#pr-targeting))
- [ ] provided a link to the relevant issue or specification
- [ ] followed the guidelines for [building modules](https://github.com/cosmos/cosmos-sdk/blob/main/docs/building-modules)
- [ ] included the necessary unit and integration [tests](https://github.com/cosmos/cosmos-sdk/blob/main/CONTRIBUTING.md#testing)
- [ ] added a changelog entry to `CHANGELOG.md`
- [ ] included comments for [documenting Go code](https://blog.golang.org/godoc)
- [ ] updated the relevant documentation or specification
- [ ] reviewed "Files changed" and left comments if necessary
- [ ] confirmed all CI checks have passed

### Reviewers Checklist

*All items are required. Please add a note if the item is not applicable and please add
your handle next to the items reviewed if you only reviewed selected items.*

I have...

- [ ] confirmed the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [ ] confirmed `!` in the type prefix if API or client breaking change
- [ ] confirmed all author checklist items have been addressed 
- [ ] reviewed state machine logic
- [ ] reviewed API design and naming
- [ ] reviewed documentation is accurate
- [ ] reviewed tests and test coverage
- [ ] manually tested (if applicable)

CHANGELOG.md

@@ -113,6 +113,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 * (appModule) Remove `Route`, `QuerierRoute` and `LegacyQuerierHandler` from AppModule Interface. 
 * (x/modules) Remove all LegacyQueries and related code from modules
 * (store) [#11825](https://github.com/cosmos/cosmos-sdk/pull/11825) Make extension snapshotter interface safer to use, renamed the util function `WriteExtensionItem` to `WriteExtensionPayload`.
+* (x/genutil)[#12956](https://github.com/cosmos/cosmos-sdk/pull/12956) `genutil.AppModuleBasic` has a new attribute: genesis transaction validation function. The existing validation logic is implemented in `genutiltypes.DefaultMessageValidator`. Use `genutil.NewAppModuleBasic` to create a new genutil Module Basic.
 * (codec) [#12964](https://github.com/cosmos/cosmos-sdk/pull/12964) `ProtoCodec.MarshalInterface` now returns an error when serializing unregistered types and a subsequent `ProtoCodec.UnmarshalInterface` would fail.
 * (x/staking) [#12973](https://github.com/cosmos/cosmos-sdk/pull/12973) Removed `stakingkeeper.RandomValidator`. Use `testutil.RandSliceElem(r, sk.GetAllValidators(ctx))` instead.
 

simapp/app.go

@@ -97,7 +97,7 @@ var (
 	// and genesis verification.
 	ModuleBasics = module.NewBasicManager(
 		auth.AppModuleBasic{},
-		genutil.AppModuleBasic{},
+		genutil.NewAppModuleBasic(genutiltypes.DefaultMessageValidator),
 		bank.AppModuleBasic{},
 		capability.AppModuleBasic{},
 		staking.AppModuleBasic{},

simapp/app_legacy.go

@@ -107,7 +107,7 @@ var (
 	// and genesis verification.
 	ModuleBasics = module.NewBasicManager(
 		auth.AppModuleBasic{},
-		genutil.AppModuleBasic{},
+		genutil.NewAppModuleBasic(genutiltypes.DefaultMessageValidator),
 		bank.AppModuleBasic{},
 		capability.AppModuleBasic{},
 		staking.AppModuleBasic{},

simapp/simd/cmd/root.go

@@ -35,7 +35,9 @@ import (
 	"github.com/cosmos/cosmos-sdk/x/auth/types"
 	banktypes "github.com/cosmos/cosmos-sdk/x/bank/types"
 	"github.com/cosmos/cosmos-sdk/x/crisis"
+	"github.com/cosmos/cosmos-sdk/x/genutil"
 	genutilcli "github.com/cosmos/cosmos-sdk/x/genutil/client/cli"
+	genutiltypes "github.com/cosmos/cosmos-sdk/x/genutil/types"
 )
 
 // NewRootCmd creates a new root command for simd. It is called once in the
@@ -165,12 +167,15 @@ lru_size = 0`
 func initRootCmd(rootCmd *cobra.Command, encodingConfig params.EncodingConfig) {
 	cfg := sdk.GetConfig()
 	cfg.Seal()
+	gentxModule := simapp.ModuleBasics[genutiltypes.ModuleName].(genutil.AppModuleBasic)
 
 	rootCmd.AddCommand(
 		genutilcli.InitCmd(simapp.ModuleBasics, simapp.DefaultNodeHome),
-		genutilcli.CollectGenTxsCmd(banktypes.GenesisBalancesIterator{}, simapp.DefaultNodeHome),
+		genutilcli.CollectGenTxsCmd(banktypes.GenesisBalancesIterator{}, simapp.DefaultNodeHome,
+			gentxModule.GenTxValidator),
 		genutilcli.MigrateGenesisCmd(),
-		genutilcli.GenTxCmd(simapp.ModuleBasics, encodingConfig.TxConfig, banktypes.GenesisBalancesIterator{}, simapp.DefaultNodeHome),
+		genutilcli.GenTxCmd(simapp.ModuleBasics, encodingConfig.TxConfig,
+			banktypes.GenesisBalancesIterator{}, simapp.DefaultNodeHome),
 		genutilcli.ValidateGenesisCmd(simapp.ModuleBasics),
 		AddGenesisAccountCmd(simapp.DefaultNodeHome),
 		tmcli.NewCompletionCmd(rootCmd, true),

simapp/simd/cmd/testnet.go

@@ -421,7 +421,7 @@ func collectGenFiles(
 			return err
 		}
 
-		nodeAppState, err := genutil.GenAppStateFromConfig(clientCtx.Codec, clientCtx.TxConfig, nodeConfig, initCfg, *genDoc, genBalIterator)
+		nodeAppState, err := genutil.GenAppStateFromConfig(clientCtx.Codec, clientCtx.TxConfig, nodeConfig, initCfg, *genDoc, genBalIterator, genutiltypes.DefaultMessageValidator)
 		if err != nil {
 			return err
 		}

testutil/network/util.go

@@ -136,7 +136,7 @@ func collectGenFiles(cfg Config, vals []*Validator, outputDir string) error {
 		}
 
 		appState, err := genutil.GenAppStateFromConfig(cfg.Codec, cfg.TxConfig,
-			tmCfg, initCfg, *genDoc, banktypes.GenesisBalancesIterator{})
+			tmCfg, initCfg, *genDoc, banktypes.GenesisBalancesIterator{}, genutiltypes.DefaultMessageValidator)
 		if err != nil {
 			return err
 		}

x/genutil/client/cli/collect.go

@@ -18,7 +18,7 @@ import (
 const flagGenTxDir = "gentx-dir"
 
 // CollectGenTxsCmd - return the cobra command to collect genesis transactions
-func CollectGenTxsCmd(genBalIterator types.GenesisBalancesIterator, defaultNodeHome string) *cobra.Command {
+func CollectGenTxsCmd(genBalIterator types.GenesisBalancesIterator, defaultNodeHome string, validator types.MessageValidator) *cobra.Command {
 	cmd := &cobra.Command{
 		Use:   "collect-gentxs",
 		Short: "Collect genesis txs and output a genesis.json file",
@@ -52,7 +52,7 @@ func CollectGenTxsCmd(genBalIterator types.GenesisBalancesIterator, defaultNodeH
 
 			appMessage, err := genutil.GenAppStateFromConfig(cdc,
 				clientCtx.TxConfig,
-				config, initCfg, *genDoc, genBalIterator)
+				config, initCfg, *genDoc, genBalIterator, validator)
 			if err != nil {
 				return errors.Wrap(err, "failed to get genesis app state from config")
 			}

x/genutil/collect.go

@@ -26,11 +26,11 @@ import (
 // GenAppStateFromConfig gets the genesis app state from the config
 func GenAppStateFromConfig(cdc codec.JSONCodec, txEncodingConfig client.TxEncodingConfig,
 	config *cfg.Config, initCfg types.InitConfig, genDoc tmtypes.GenesisDoc, genBalIterator types.GenesisBalancesIterator,
+	validator types.MessageValidator,
 ) (appState json.RawMessage, err error) {
 	// process genesis transactions, else create default genesis.json
 	appGenTxs, persistentPeers, err := CollectTxs(
-		cdc, txEncodingConfig.TxJSONDecoder(), config.Moniker, initCfg.GenTxsDir, genDoc, genBalIterator,
-	)
+		cdc, txEncodingConfig.TxJSONDecoder(), config.Moniker, initCfg.GenTxsDir, genDoc, genBalIterator, validator)
 	if err != nil {
 		return appState, err
 	}
@@ -69,6 +69,7 @@ func GenAppStateFromConfig(cdc codec.JSONCodec, txEncodingConfig client.TxEncodi
 // the list of appGenTxs, and persistent peers required to generate genesis.json.
 func CollectTxs(cdc codec.JSONCodec, txJSONDecoder sdk.TxDecoder, moniker, genTxsDir string,
 	genDoc tmtypes.GenesisDoc, genBalIterator types.GenesisBalancesIterator,
+	validator types.MessageValidator,
 ) (appGenTxs []sdk.Tx, persistentPeers string, err error) {
 	// prepare a map of all balances in genesis state to then validate
 	// against the validators addresses
@@ -110,7 +111,7 @@ func CollectTxs(cdc codec.JSONCodec, txJSONDecoder sdk.TxDecoder, moniker, genTx
 			return appGenTxs, persistentPeers, err
 		}
 
-		genTx, err := types.ValidateAndGetGenTx(jsonRawTx, txJSONDecoder)
+		genTx, err := types.ValidateAndGetGenTx(jsonRawTx, txJSONDecoder, validator)
 		if err != nil {
 			return appGenTxs, persistentPeers, err
 		}

x/genutil/collect_test.go

@@ -61,7 +61,7 @@ func TestCollectTxsHandlesDirectories(t *testing.T) {
 	balItr := new(doNothingIterator)
 
 	dnc := &doNothingUnmarshalJSON{cdc}
-	if _, _, err := genutil.CollectTxs(dnc, txDecoder, "foo", testDir, gdoc, balItr); err != nil {
+	if _, _, err := genutil.CollectTxs(dnc, txDecoder, "foo", testDir, gdoc, balItr, gtypes.DefaultMessageValidator); err != nil {
 		t.Fatal(err)
 	}
 }

x/genutil/module.go

@@ -27,7 +27,15 @@ var (
 )
 
 // AppModuleBasic defines the basic application module used by the genutil module.
-type AppModuleBasic struct{}
+type AppModuleBasic struct {
+	GenTxValidator types.MessageValidator
+}
+
+// NewAppModuleBasic creates AppModuleBasic, validator is a function used to validate genesis
+// transactions.
+func NewAppModuleBasic(validator types.MessageValidator) AppModuleBasic {
+	return AppModuleBasic{validator}
+}
 
 // Name returns the genutil module's name.
 func (AppModuleBasic) Name() string {
@@ -53,7 +61,7 @@ func (b AppModuleBasic) ValidateGenesis(cdc codec.JSONCodec, txEncodingConfig cl
 		return fmt.Errorf("failed to unmarshal %s genesis state: %w", types.ModuleName, err)
 	}
 
-	return types.ValidateGenesis(&data, txEncodingConfig.TxJSONDecoder())
+	return types.ValidateGenesis(&data, txEncodingConfig.TxJSONDecoder(), b.GenTxValidator)
 }
 
 // RegisterGRPCGatewayRoutes registers the gRPC Gateway routes for the genutil module.

x/genutil/types/genesis_state.go

@@ -93,9 +93,9 @@ func GenesisStateFromGenFile(genFile string) (genesisState map[string]json.RawMe
 }
 
 // ValidateGenesis validates GenTx transactions
-func ValidateGenesis(genesisState *GenesisState, txJSONDecoder sdk.TxDecoder) error {
+func ValidateGenesis(genesisState *GenesisState, txJSONDecoder sdk.TxDecoder, validator MessageValidator) error {
 	for _, genTx := range genesisState.GenTxs {
-		_, err := ValidateAndGetGenTx(genTx, txJSONDecoder)
+		_, err := ValidateAndGetGenTx(genTx, txJSONDecoder, validator)
 		if err != nil {
 			return err
 		}
@@ -103,27 +103,29 @@ func ValidateGenesis(genesisState *GenesisState, txJSONDecoder sdk.TxDecoder) er
 	return nil
 }
 
+type MessageValidator func([]sdk.Msg) error
+
+func DefaultMessageValidator(msgs []sdk.Msg) error {
+	if len(msgs) != 1 {
+		return fmt.Errorf("unexpected number of GenTx messages; got: %d, expected: 1", len(msgs))
+	}
+	if _, ok := msgs[0].(*stakingtypes.MsgCreateValidator); !ok {
+		return fmt.Errorf("unexpected GenTx message type; expected: MsgCreateValidator, got: %T", msgs[0])
+	}
+	if err := msgs[0].ValidateBasic(); err != nil {
+		return fmt.Errorf("invalid GenTx '%s': %w", msgs[0], err)
+	}
+
+	return nil
+}
+
 // ValidateAndGetGenTx validates the genesis transaction and returns GenTx if valid
 // it cannot verify the signature as it is stateless validation
-func ValidateAndGetGenTx(genTx json.RawMessage, txJSONDecoder sdk.TxDecoder) (sdk.Tx, error) {
+func ValidateAndGetGenTx(genTx json.RawMessage, txJSONDecoder sdk.TxDecoder, validator MessageValidator) (sdk.Tx, error) {
 	tx, err := txJSONDecoder(genTx)
 	if err != nil {
 		return tx, fmt.Errorf("failed to decode gentx: %s, error: %s", genTx, err)
 	}
 
-	msgs := tx.GetMsgs()
-	if len(msgs) != 1 {
-		return tx, fmt.Errorf("unexpected number of GenTx messages; got: %d, expected: 1", len(msgs))
-	}
-
-	// TODO: abstract back to staking
-	if _, ok := msgs[0].(*stakingtypes.MsgCreateValidator); !ok {
-		return tx, fmt.Errorf("unexpected GenTx message type; expected: MsgCreateValidator, got: %T", msgs[0])
-	}
-
-	if err := msgs[0].ValidateBasic(); err != nil {
-		return tx, fmt.Errorf("invalid GenTx '%s': %s", msgs[0], err)
-	}
-
-	return tx, nil
+	return tx, validator(tx.GetMsgs())
 }

x/genutil/types/genesis_state_test.go

@@ -55,7 +55,7 @@ func TestValidateGenesisMultipleMessages(t *testing.T) {
 	tx := txBuilder.GetTx()
 	genesisState := types.NewGenesisStateFromTx(txConfig.TxJSONEncoder(), []sdk.Tx{tx})
 
-	err = types.ValidateGenesis(genesisState, txConfig.TxJSONDecoder())
+	err = types.ValidateGenesis(genesisState, txConfig.TxJSONDecoder(), types.DefaultMessageValidator)
 	require.Error(t, err)
 }
 
@@ -72,7 +72,7 @@ func TestValidateGenesisBadMessage(t *testing.T) {
 	tx := txBuilder.GetTx()
 	genesisState := types.NewGenesisStateFromTx(txConfig.TxJSONEncoder(), []sdk.Tx{tx})
 
-	err = types.ValidateGenesis(genesisState, txConfig.TxJSONDecoder())
+	err = types.ValidateGenesis(genesisState, txConfig.TxJSONDecoder(), types.DefaultMessageValidator)
 	require.Error(t, err)
 }