feat: Add AuxTxBuilder

client/tx/aux_builder.go

@@ -0,0 +1,149 @@
+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"
+)
+
+// AuxTxBuilder is a client-side builder for creating an AuxTx.
+type AuxTxBuilder struct {
+	body          *tx.TxBody
+	auxSignerData *tx.AuxSignerData
+}
+
+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.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) 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) {
+	body := b.body
+	if body == nil {
+		return nil, sdkerrors.ErrLogic.Wrap("tx body is nil, call setters on AuxTxBuilder first")
+	}
+
+	bodyBz, err := proto.Marshal(body)
+	if err != nil {
+		return nil, err
+	}
+
+	auxTx := b.auxSignerData
+	if auxTx == nil {
+		return nil, sdkerrors.ErrLogic.Wrap("aux tx 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")
+	}
+
+	sd.BodyBytes = bodyBz
+
+	if err := b.auxSignerData.SignDoc.ValidateBasic(); err != nil {
+		return nil, err
+	}
+
+	signBz, err := proto.Marshal(b.auxSignerData.SignDoc)
+	if err != nil {
+		return nil, err
+	}
+
+	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{}
+		}
+	}
+}

docs/core/proto-docs.md

@@ -661,6 +661,7 @@
 
 - [cosmos/tx/v1beta1/tx.proto](#cosmos/tx/v1beta1/tx.proto)
     - [AuthInfo](#cosmos.tx.v1beta1.AuthInfo)
+    - [AuxSignerData](#cosmos.tx.v1beta1.AuxSignerData)
     - [Fee](#cosmos.tx.v1beta1.Fee)
     - [ModeInfo](#cosmos.tx.v1beta1.ModeInfo)
     - [ModeInfo.Multi](#cosmos.tx.v1beta1.ModeInfo.Multi)
@@ -9474,6 +9475,25 @@ Since: cosmos-sdk 0.45 |
 
 
 
+<a name="cosmos.tx.v1beta1.AuxSignerData"></a>
+
+### AuxSignerData
+AuxSignerData is the intermediary format that an auxiliary signer (e.g. a
+tipper) builds and sends to the fee payer (who will build and broadcast the
+actual tx). AuxSignerData is not a valid tx in itself, and will be rejected
+by the node if sent directly as-is.
+
+
+| Field | Type | Label | Description |
+| ----- | ---- | ----- | ----------- |
+| `sign_doc` | [SignDocDirectAux](#cosmos.tx.v1beta1.SignDocDirectAux) |  | sign_doc is the SIGN_MOD_DIRECT_AUX sign doc that the auxiliary signer signs. |
+| `sig` | [bytes](#bytes) |  | sig is the signature of the sign doc. |
+
+
+
+
+
+
 <a name="cosmos.tx.v1beta1.Fee"></a>
 
 ### Fee

proto/cosmos/tx/v1beta1/tx.proto

@@ -221,3 +221,15 @@ message Tip {
   // tipper is the address of the account paying for the tip
   string tipper = 2 [(cosmos_proto.scalar) = "cosmos.AddressString"];
 }
+
+// AuxSignerData is the intermediary format that an auxiliary signer (e.g. a
+// tipper) builds and sends to the fee payer (who will build and broadcast the
+// actual tx). AuxSignerData is not a valid tx in itself, and will be rejected
+// by the node if sent directly as-is.
+message AuxSignerData {
+	// sign_doc is the SIGN_MOD_DIRECT_AUX sign doc that the auxiliary signer
+  // signs.
+	SignDocDirectAux sign_doc = 1;
+	// sig is the signature of the sign doc.
+	bytes sig = 2;
+}

types/tx/aux.go

@@ -0,0 +1,49 @@
+package tx
+
+import (
+	codectypes "github.com/cosmos/cosmos-sdk/codec/types"
+	cryptotypes "github.com/cosmos/cosmos-sdk/crypto/types"
+	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
+)
+
+// ValidateBasic performs stateless validation of the sign doc.
+func (s *SignDocDirectAux) ValidateBasic() error {
+	if len(s.BodyBytes) == 0 {
+		return sdkerrors.ErrInvalidRequest.Wrap("body bytes cannot be empty")
+	}
+
+	if s.PublicKey == nil {
+		return sdkerrors.ErrInvalidPubKey.Wrap("public key cannot be empty")
+	}
+
+	if s.Tip != nil {
+		if len(s.Tip.Amount) == 0 {
+			return sdkerrors.ErrInvalidRequest.Wrap("tip amount cannot be empty")
+		}
+
+		if s.Tip.Tipper == "" {
+			return sdkerrors.ErrInvalidRequest.Wrap("tipper cannot be empty")
+		}
+	}
+
+	return nil
+}
+
+// UnpackInterfaces implements the UnpackInterfaceMessages.UnpackInterfaces method
+func (s *SignDocDirectAux) UnpackInterfaces(unpacker codectypes.AnyUnpacker) error {
+	return unpacker.UnpackAny(s.PublicKey, new(cryptotypes.PubKey))
+}
+
+// ValidateBasic performs stateless validation of the auxiliary tx.
+func (a *AuxTx) ValidateBasic() error {
+	if len(a.Sig) == 0 {
+		return sdkerrors.ErrNoSignatures.Wrap("signature cannot be empty")
+	}
+
+	return a.GetSignDoc().ValidateBasic()
+}
+
+// UnpackInterfaces implements the UnpackInterfaceMessages.UnpackInterfaces method
+func (a *AuxTx) UnpackInterfaces(unpacker codectypes.AnyUnpacker) error {
+	return a.GetSignDoc().UnpackInterfaces(unpacker)
+}