feat(x/staking): implement RotateConsPubKey method (#18188)

x/staking/keeper/msg_server.go

@@ -2,6 +2,7 @@ package keeper
 
 import (
 	"context"
+	"errors"
 	"strconv"
 	"time"
 
@@ -9,6 +10,7 @@ import (
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
 
+	"cosmossdk.io/collections"
 	errorsmod "cosmossdk.io/errors"
 	"cosmossdk.io/math"
 	"cosmossdk.io/x/staking/types"
@@ -605,6 +607,76 @@ func (k msgServer) UpdateParams(ctx context.Context, msg *types.MsgUpdateParams)
 	return &types.MsgUpdateParamsResponse{}, nil
 }
 
-func (k msgServer) RotateConsPubKey(_ context.Context, _ *types.MsgRotateConsPubKey) (*types.MsgRotateConsPubKeyResponse, error) {
-	return nil, nil
+func (k msgServer) RotateConsPubKey(ctx context.Context, msg *types.MsgRotateConsPubKey) (res *types.MsgRotateConsPubKeyResponse, err error) {
+	cv := msg.NewPubkey.GetCachedValue()
+	pk, ok := cv.(cryptotypes.PubKey)
+	if !ok {
+		return nil, errorsmod.Wrapf(sdkerrors.ErrInvalidType, "expecting cryptotypes.PubKey, got %T", cv)
+	}
+
+	// check cons key is already present in the key rotation history.
+	rotatedTo, err := k.RotatedConsKeyMapIndex.Get(ctx, pk.Address())
+	if err != nil && !errors.Is(err, collections.ErrNotFound) {
+		return nil, err
+	}
+
+	if rotatedTo != nil {
+		return nil, errorsmod.Wrap(sdkerrors.ErrInvalidAddress,
+			"the new public key is already present in rotation history, please try with a different one")
+	}
+
+	newConsAddr := sdk.ConsAddress(pk.Address())
+
+	// checks if NewPubKey is not duplicated on ValidatorsByConsAddr
+	validator1, _ := k.Keeper.ValidatorByConsAddr(ctx, newConsAddr)
+	if validator1 != nil {
+		return nil, types.ErrConsensusPubKeyAlreadyUsedForValidator
+	}
+
+	valAddr, err := k.validatorAddressCodec.StringToBytes(msg.ValidatorAddress)
+	if err != nil {
+		return nil, err
+	}
+
+	validator2, err := k.Keeper.GetValidator(ctx, valAddr)
+	if err != nil {
+		return nil, types.ErrNoValidatorFound
+	}
+
+	if status := validator2.GetStatus(); status != types.Bonded {
+		return nil, errorsmod.Wrapf(sdkerrors.ErrInvalidType, "validator status is not bonded, got %s", status.String())
+	}
+
+	// Check if the validator is exceeding parameter MaxConsPubKeyRotations within the
+	// unbonding period by iterating ConsPubKeyRotationHistory.
+	err = k.exceedsMaxRotations(ctx, valAddr)
+	if err != nil {
+		return nil, err
+	}
+
+	// Check if the signing account has enough balance to pay KeyRotationFee
+	// KeyRotationFees are sent to the community fund.
+	params, err := k.Params.Get(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	err = k.Keeper.bankKeeper.SendCoinsFromAccountToModule(ctx, sdk.AccAddress(valAddr), types.DistributionModuleName, sdk.NewCoins(params.KeyRotationFee))
+	if err != nil {
+		return nil, err
+	}
+
+	// Add ConsPubKeyRotationHistory for tracking rotation
+	err = k.setConsPubKeyRotationHistory(
+		ctx,
+		valAddr,
+		validator2.ConsensusPubkey,
+		msg.NewPubkey,
+		params.KeyRotationFee,
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	return res, nil
 }