feat: add IBC ante handler (#717)

## Description
This PR adds the IBC `AnteHandler` to the list of ante handlers. Closes #714

Depends-On: #716

---

### 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...

- [x] 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/desmos-labs/desmos/blob/master/CONTRIBUTING.md#pr-targeting))
- [ ] provided a link to the relevant issue or specification
- [ ] followed the guidelines for [building modules](https://docs.cosmos.network/v0.44/building-modules/intro.html)
- [ ] included the necessary unit and integration [tests](https://github.com/desmos-labs/desmos/blob/master/CONTRIBUTING.md#testing)
- [x] added a changelog entry to `CHANGELOG.md`
- [ ] included comments for [documenting Go code](https://blog.golang.org/godoc)
- [ ] updated the relevant documentation or specification
- [x] 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)

.changeset/entries/034df6ee16191e8ca2f4ccb5f622fe7253090f6ff773a1797febb2c27b69e70f.yaml

@@ -0,0 +1,6 @@
+type: feat
+module: none
+pull_request: 717
+description: Added IBC AnteHandler
+backward_compatible: true
+date: 2022-01-10T10:48:44.785928578Z

app/ante.go

@@ -0,0 +1,54 @@
+package app
+
+import (
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
+	"github.com/cosmos/cosmos-sdk/x/auth/ante"
+	channelkeeper "github.com/cosmos/ibc-go/v2/modules/core/04-channel/keeper"
+	ibcante "github.com/cosmos/ibc-go/v2/modules/core/ante"
+)
+
+// HandlerOptions extend the SDK's AnteHandler options by requiring the IBC
+// channel keeper.
+type HandlerOptions struct {
+	ante.HandlerOptions
+
+	IBCChannelkeeper channelkeeper.Keeper
+}
+
+func NewAnteHandler(options HandlerOptions) (sdk.AnteHandler, error) {
+	if options.AccountKeeper == nil {
+		return nil, sdkerrors.Wrap(sdkerrors.ErrLogic, "account keeper is required for AnteHandler")
+	}
+	if options.BankKeeper == nil {
+		return nil, sdkerrors.Wrap(sdkerrors.ErrLogic, "bank keeper is required for AnteHandler")
+	}
+	if options.SignModeHandler == nil {
+		return nil, sdkerrors.Wrap(sdkerrors.ErrLogic, "sign mode handler is required for ante builder")
+	}
+
+	var sigGasConsumer = options.SigGasConsumer
+	if sigGasConsumer == nil {
+		sigGasConsumer = ante.DefaultSigVerificationGasConsumer
+	}
+
+	anteDecorators := []sdk.AnteDecorator{
+		ante.NewSetUpContextDecorator(),
+		ante.NewRejectExtensionOptionsDecorator(),
+		ante.NewMempoolFeeDecorator(),
+		ante.NewValidateBasicDecorator(),
+		ante.NewTxTimeoutHeightDecorator(),
+		ante.NewValidateMemoDecorator(options.AccountKeeper),
+		ante.NewConsumeGasForTxSizeDecorator(options.AccountKeeper),
+		ante.NewDeductFeeDecorator(options.AccountKeeper, options.BankKeeper, options.FeegrantKeeper),
+		// SetPubKeyDecorator must be called before all signature verification decorators
+		ante.NewSetPubKeyDecorator(options.AccountKeeper),
+		ante.NewValidateSigCountDecorator(options.AccountKeeper),
+		ante.NewSigGasConsumeDecorator(options.AccountKeeper, sigGasConsumer),
+		ante.NewSigVerificationDecorator(options.AccountKeeper, options.SignModeHandler),
+		ante.NewIncrementSequenceDecorator(options.AccountKeeper),
+		ibcante.NewAnteDecorator(options.IBCChannelkeeper),
+	}
+
+	return sdk.ChainAnteDecorators(anteDecorators...), nil
+}

app/app.go

@@ -484,13 +484,16 @@ func NewDesmosApp(
 	// Initialize BaseApp
 	app.SetInitChainer(app.InitChainer)
 	app.SetBeginBlocker(app.BeginBlocker)
-	anteHandler, err := ante.NewAnteHandler(
-		ante.HandlerOptions{
-			AccountKeeper:   app.AccountKeeper,
-			BankKeeper:      app.BankKeeper,
-			SignModeHandler: encodingConfig.TxConfig.SignModeHandler(),
-			FeegrantKeeper:  app.FeeGrantKeeper,
-			SigGasConsumer:  ante.DefaultSigVerificationGasConsumer,
+	anteHandler, err := NewAnteHandler(
+		HandlerOptions{
+			HandlerOptions: ante.HandlerOptions{
+				AccountKeeper:   app.AccountKeeper,
+				BankKeeper:      app.BankKeeper,
+				SignModeHandler: encodingConfig.TxConfig.SignModeHandler(),
+				FeegrantKeeper:  app.FeeGrantKeeper,
+				SigGasConsumer:  ante.DefaultSigVerificationGasConsumer,
+			},
+			IBCChannelkeeper: app.IBCKeeper.ChannelKeeper,
 		},
 	)
 	if err != nil {