feat: Add AuxTxBuilder

client/tx/aux_builder.go

@@ -0,0 +1,195 @@
+package tx
+
+import (
+	"github.com/gogo/protobuf/proto"
+
+	codectypes "github.com/cosmos/cosmos-sdk/codec/types"
+	cryptotypes "github.com/cosmos/cosmos-sdk/crypto/types"
+	sdk "github.com/cosmos/cosmos-sdk/types"
+	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
+	"github.com/cosmos/cosmos-sdk/types/tx"
+	"github.com/cosmos/cosmos-sdk/types/tx/signing"
+	"github.com/cosmos/cosmos-sdk/x/auth/migrations/legacytx"
+)
+
+// AuxTxBuilder is a client-side builder for creating an AuxTx.
+type AuxTxBuilder struct {
+	// msgs is used to store the sdk.Msgs that are added to the
+	// TxBuilder. It's also added inside body.Messages, because:
+	// - b.msgs is used for constructing the AMINO sign bz,
+	// - b.body is used for constructing the DIRECT_AUX sign bz.
+	msgs          []sdk.Msg
+	body          *tx.TxBody
+	auxSignerData *tx.AuxSignerData
+}
+
+func NewAuxTxBuilder() AuxTxBuilder {
+	return AuxTxBuilder{}
+}
+
+func (b *AuxTxBuilder) SetMemo(memo string) {
+	b.checkEmptyFields()
+
+	b.body.Memo = memo
+}
+
+func (b *AuxTxBuilder) SetTimeoutHeight(height uint64) {
+	b.checkEmptyFields()
+
+	b.body.TimeoutHeight = height
+}
+
+func (b *AuxTxBuilder) SetMsgs(msgs ...sdk.Msg) error {
+	anys := make([]*codectypes.Any, len(msgs))
+	for i, msg := range msgs {
+		var err error
+		anys[i], err = codectypes.NewAnyWithValue(msg)
+		if err != nil {
+			return err
+		}
+	}
+
+	b.checkEmptyFields()
+
+	b.msgs = msgs
+	b.body.Messages = anys
+
+	return nil
+}
+
+func (b *AuxTxBuilder) SetAccountNumber(accNum uint64) {
+	b.checkEmptyFields()
+
+	b.auxSignerData.SignDoc.AccountNumber = accNum
+}
+
+func (b *AuxTxBuilder) SetChainID(chainID string) {
+	b.checkEmptyFields()
+
+	b.auxSignerData.SignDoc.ChainId = chainID
+}
+
+func (b *AuxTxBuilder) SetSequence(accSeq uint64) {
+	b.checkEmptyFields()
+
+	b.auxSignerData.SignDoc.Sequence = accSeq
+}
+
+func (b *AuxTxBuilder) SetPubKey(pk cryptotypes.PubKey) error {
+	any, err := codectypes.NewAnyWithValue(pk)
+	if err != nil {
+		return err
+	}
+
+	b.checkEmptyFields()
+
+	b.auxSignerData.SignDoc.PublicKey = any
+
+	return nil
+}
+
+func (b *AuxTxBuilder) SetSignMode(mode signing.SignMode) error {
+	switch mode {
+	case signing.SignMode_SIGN_MODE_DIRECT_AUX, signing.SignMode_SIGN_MODE_LEGACY_AMINO_JSON:
+	default:
+		return sdkerrors.ErrInvalidRequest.Wrapf("AuxTxBuilder can only sign with %s or %s", signing.SignMode_SIGN_MODE_DIRECT_AUX, signing.SignMode_SIGN_MODE_LEGACY_AMINO_JSON)
+	}
+
+	b.auxSignerData.Mode = mode
+
+	return nil
+}
+
+func (b *AuxTxBuilder) SetTip(tip *tx.Tip) {
+	b.checkEmptyFields()
+
+	b.auxSignerData.SignDoc.Tip = tip
+}
+
+func (b *AuxTxBuilder) SetSignature(sig []byte) {
+	if b.auxSignerData == nil {
+		b.auxSignerData = &tx.AuxSignerData{}
+	}
+
+	b.auxSignerData.Sig = sig
+}
+
+// GetSignBytes returns the builder's sign bytes.
+func (b *AuxTxBuilder) GetSignBytes() ([]byte, error) {
+	auxTx := b.auxSignerData
+	if auxTx == nil {
+		return nil, sdkerrors.ErrLogic.Wrap("aux tx is nil, call setters on AuxTxBuilder first")
+	}
+
+	body := b.body
+	if body == nil {
+		return nil, sdkerrors.ErrLogic.Wrap("tx body is nil, call setters on AuxTxBuilder first")
+	}
+
+	sd := auxTx.SignDoc
+	if sd == nil {
+		return nil, sdkerrors.ErrLogic.Wrap("sign doc is nil, call setters on AuxTxBuilder first")
+	}
+
+	bodyBz, err := proto.Marshal(body)
+	if err != nil {
+		return nil, err
+	}
+
+	sd.BodyBytes = bodyBz
+
+	if err := b.auxSignerData.SignDoc.ValidateBasic(); err != nil {
+		return nil, err
+	}
+
+	var signBz []byte
+	switch b.auxSignerData.Mode {
+	case signing.SignMode_SIGN_MODE_DIRECT_AUX:
+		{
+
+			signBz, err = proto.Marshal(b.auxSignerData.SignDoc)
+			if err != nil {
+				return nil, err
+			}
+		}
+	case signing.SignMode_SIGN_MODE_LEGACY_AMINO_JSON:
+		{
+			signBz = legacytx.StdSignBytes(
+				b.auxSignerData.SignDoc.ChainId, b.auxSignerData.SignDoc.AccountNumber,
+				b.auxSignerData.SignDoc.Sequence, b.body.TimeoutHeight,
+				// Aux signer never signs over fee.
+				// For LEGACY_AMINO_JSON, we use the convention to sign
+				// over empty fees.
+				// ref: https://github.com/cosmos/cosmos-sdk/pull/10348
+				legacytx.StdFee{},
+				b.msgs, b.body.Memo, b.auxSignerData.SignDoc.Tip,
+			)
+		}
+	default:
+		return nil, sdkerrors.ErrInvalidRequest.Wrapf("got unknown sign mode %s", b.auxSignerData.Mode)
+	}
+
+	return signBz, nil
+}
+
+// GetAuxTx returns the builder's AuxTx.
+func (b *AuxTxBuilder) GetAuxTx() (*tx.AuxSignerData, error) {
+	if err := b.auxSignerData.ValidateBasic(); err != nil {
+		return nil, err
+	}
+
+	return b.auxSignerData, nil
+}
+
+func (b *AuxTxBuilder) checkEmptyFields() {
+	if b.body == nil {
+		b.body = &tx.TxBody{}
+	}
+
+	if b.auxSignerData == nil {
+		b.auxSignerData = &tx.AuxSignerData{}
+		if b.auxSignerData.SignDoc == nil {
+			b.auxSignerData.SignDoc = &tx.SignDocDirectAux{}
+		}
+	}
+}