feat: Implement Misbehaviour component

cosmos/sidechain/x/clients/mithril/header.go

@@ -55,6 +55,9 @@ func (h MithrilHeader) ValidateBasic() error {
 	if h.TransactionSnapshotCertificate == nil {
 		return errorsmod.Wrap(ErrInvalidTransactionSnapshotCertificate, "transaction snapshot certificate cannot be nil")
 	}
+	if h.MithrilStakeDistribution.Epoch != h.TransactionSnapshot.Epoch {
+		return errorsmod.Wrap(ErrInvalidMithrilHeader, "mithril stake distribution epoch does not match transaction snapshot epoch")
+	}
 	if !strings.EqualFold(h.MithrilStakeDistribution.CertificateHash, h.MithrilStakeDistributionCertificate.Hash) {
 		return errorsmod.Wrap(ErrInvalidMithrilHeader, "mithril stake distribution does not match mithril stake distribution certificate")
 	}

cosmos/sidechain/x/clients/mithril/misbehavour.go

@@ -0,0 +1,80 @@
+package mithril
+
+import (
+	"time"
+
+	errorsmod "cosmossdk.io/errors"
+
+	clienttypes "github.com/cosmos/ibc-go/v8/modules/core/02-client/types"
+	host "github.com/cosmos/ibc-go/v8/modules/core/24-host"
+	"github.com/cosmos/ibc-go/v8/modules/core/exported"
+)
+
+var _ exported.ClientMessage = (*Misbehaviour)(nil)
+
+// FrozenHeight is same for all misbehaviour
+var FrozenHeight = NewHeight(1)
+
+// NewMisbehaviour creates a new Misbehaviour instance.
+func NewMisbehaviour(clientID string, header1, header2 *MithrilHeader) *Misbehaviour {
+	return &Misbehaviour{
+		ClientId:       clientID,
+		MithrilHeader1: header1,
+		MithrilHeader2: header2,
+	}
+}
+
+// ClientType is Mithril light client
+func (Misbehaviour) ClientType() string {
+	return ModuleName
+}
+
+// GetTime returns the timestamp at which misbehaviour occurred. It uses the
+// maximum value from both headers to prevent producing an invalid header outside
+// of the misbehaviour age range.
+func (misbehaviour Misbehaviour) GetTime() time.Time {
+	t1, t2 := misbehaviour.MithrilHeader1.GetTime(), misbehaviour.MithrilHeader2.GetTime()
+	if t1.After(t2) {
+		return t1
+	}
+	return t2
+}
+
+// ValidateBasic implements Misbehaviour interface
+func (misbehaviour Misbehaviour) ValidateBasic() error {
+	if misbehaviour.MithrilHeader1 == nil {
+		return errorsmod.Wrap(ErrInvalidMithrilHeader, "misbehaviour MithrilHeader1 cannot be nil")
+	}
+	if misbehaviour.MithrilHeader2 == nil {
+		return errorsmod.Wrap(ErrInvalidMithrilHeader, "misbehaviour MithrilHeader2 cannot be nil")
+	}
+	if misbehaviour.MithrilHeader1.TransactionSnapshot.Height.MithrilHeight == 0 {
+		return errorsmod.Wrapf(ErrInvalidMithrilHeaderHeight, "misbehaviour MithrilHeader1 cannot have zero mithril height")
+	}
+	if misbehaviour.MithrilHeader2.TransactionSnapshot.Height.MithrilHeight == 0 {
+		return errorsmod.Wrapf(ErrInvalidMithrilHeaderHeight, "misbehaviour MithrilHeader2 cannot have zero mithril height")
+	}
+	if err := host.ClientIdentifierValidator(misbehaviour.ClientId); err != nil {
+		return errorsmod.Wrap(err, "misbehaviour client ID is invalid")
+	}
+
+	// ValidateBasic on both MithrilHeader
+	if err := misbehaviour.MithrilHeader1.ValidateBasic(); err != nil {
+		return errorsmod.Wrap(
+			clienttypes.ErrInvalidMisbehaviour,
+			errorsmod.Wrap(err, "mithril header 1 failed validation").Error(),
+		)
+	}
+	if err := misbehaviour.MithrilHeader2.ValidateBasic(); err != nil {
+		return errorsmod.Wrap(
+			clienttypes.ErrInvalidMisbehaviour,
+			errorsmod.Wrap(err, "mithril header 2 failed validation").Error(),
+		)
+	}
+	// Ensure that Height1 is greater than or equal to Height2
+	if misbehaviour.MithrilHeader1.GetHeight().LT(misbehaviour.MithrilHeader2.GetHeight()) {
+		return errorsmod.Wrapf(clienttypes.ErrInvalidMisbehaviour, "MithrilHeader1 height is less than MithrilHeader2 height (%s < %s)", misbehaviour.MithrilHeader1.GetHeight(), misbehaviour.MithrilHeader2.GetHeight())
+	}
+
+	return nil
+}