Add ticket ownership validation/authentication API middleware

backend/stakepoold/rpc/api.proto

@@ -14,6 +14,7 @@ service StakepooldService {
 	rpc ValidateAddress (ValidateAddressRequest) returns (ValidateAddressResponse);
 	rpc AddMissingTicket (AddMissingTicketRequest) returns (AddMissingTicketResponse);
 	rpc GetTickets (GetTicketsRequest) returns (GetTicketsResponse);
+	rpc GetTicketInfo (GetTicketInfoRequest) returns (GetTicketInfoResponse);
 	rpc ListScripts (ListScriptsRequest) returns (ListScriptsResponse);
 	rpc AccountSyncAddressIndex (AccountSyncAddressIndexRequest) returns (AccountSyncAddressIndexResponse);
 	rpc CreateMultisig (CreateMultisigRequest) returns (CreateMultisigResponse);
@@ -39,6 +40,15 @@ message GetLiveTicketsResponse {
 	repeated Ticket tickets = 1;
 }
 
+message GetTicketInfoRequest {
+    string Hash = 1;
+}
+message GetTicketInfoResponse {
+	string MultiSigAddress = 1;
+	string VspFeeAddress = 2;
+	string OwnerFeeAddress = 3;
+}
+
 message SetAddedLowFeeTicketsRequest {
 	repeated Ticket tickets = 1;
 }

backend/stakepoold/rpc/rpcserver/context.go

@@ -16,6 +16,7 @@ import (
 	wallettypes "github.com/decred/dcrwallet/rpc/jsonrpc/types"
 
 	"github.com/decred/dcrd/rpcclient/v3"
+	"github.com/decred/dcrd/txscript"
 	"github.com/decred/dcrd/wire"
 	"github.com/decred/dcrstakepool/backend/stakepoold/userdata"
 	"github.com/decred/dcrwallet/wallet/v2/txrules"
@@ -99,6 +100,12 @@ type ticketMetadata struct {
 	err          error                     // log errors along the way
 }
 
+type TicketInfo struct {
+	MultiSigAddress string
+	VspFeeAddress   string
+	OwnerFeeAddress string
+}
+
 // EvaluateStakePoolTicket evaluates a voting service ticket to see if it's
 // acceptable to the voting service. The ticket must pay out to the voting
 // service cold wallet, and must have a sufficient fee.
@@ -369,6 +376,49 @@ func (ctx *AppContext) GetTickets(includeImmature bool) ([]*chainhash.Hash, erro
 	return tickets, nil
 }
 
+func (ctx *AppContext) GetTicketInfo(ticketHash string) (ticketInfo *TicketInfo, err error) {
+	hash, err := chainhash.NewHashFromStr(ticketHash)
+	if err != nil {
+		log.Errorf("GetTicketInfo: Failed to parse ticket hash: %v", err)
+		return
+	}
+
+	res, err := ctx.WalletConnection.GetTransaction(hash)
+	if err != nil {
+		log.Errorf("GetTicketInfo: GetTransaction rpc failed: %v", err)
+		return
+	}
+
+	// get txout addresses using tx hes
+	msgTx, err := MsgTxFromHex(res.Hex)
+	if err != nil {
+		return nil, fmt.Errorf("GetTicketInfo: MsgTxFromHex failed for %v: %v", res.Hex, err)
+	}
+
+	p2shOut := msgTx.TxOut[0]
+	_, addrs, _, _ := txscript.ExtractPkScriptAddrs(p2shOut.Version, p2shOut.PkScript, ctx.Params)
+	multiSigAddress := addrs[0]
+
+	vspCommitmentOut := msgTx.TxOut[1]
+	vspCommitAddr, err := stake.AddrFromSStxPkScrCommitment(vspCommitmentOut.PkScript, ctx.Params)
+	if err != nil {
+		return nil, fmt.Errorf("GetTicketInfo: Failed to parse commit out addr: %s", err.Error())
+	}
+
+	ownerCommitmentOut := msgTx.TxOut[3]
+	ownerCommitAddr, err := stake.AddrFromSStxPkScrCommitment(ownerCommitmentOut.PkScript, ctx.Params)
+	if err != nil {
+		return nil, fmt.Errorf("GetTicketInfo: Failed to parse commit out addr: %s", err.Error())
+	}
+
+	ticketInfo = &TicketInfo{
+		MultiSigAddress: multiSigAddress.EncodeAddress(),
+		VspFeeAddress:   vspCommitAddr.EncodeAddress(),
+		OwnerFeeAddress: ownerCommitAddr.EncodeAddress(),
+	}
+	return
+}
+
 func (ctx *AppContext) StakePoolUserInfo(multisigAddress string) (*wallettypes.StakePoolUserInfoResult, error) {
 	decodedMultisig, err := dcrutil.DecodeAddress(multisigAddress)
 	if err != nil {

backend/stakepoold/rpc/rpcserver/server.go

@@ -186,6 +186,19 @@ func (s *stakepooldServer) GetTickets(ctx context.Context, req *pb.GetTicketsReq
 	return &pb.GetTicketsResponse{Tickets: ticketBytes}, nil
 }
 
+func (s *stakepooldServer) GetTicketInfo(ctx context.Context, req *pb.GetTicketInfoRequest) (*pb.GetTicketInfoResponse, error) {
+	ticketInfo, err := s.appContext.GetTicketInfo(req.Hash)
+	if err != nil {
+		return nil, err
+	}
+
+	return &pb.GetTicketInfoResponse{
+		OwnerFeeAddress: ticketInfo.OwnerFeeAddress,
+		VspFeeAddress:   ticketInfo.VspFeeAddress,
+		MultiSigAddress: ticketInfo.MultiSigAddress,
+	}, nil
+}
+
 func (s *stakepooldServer) AddMissingTicket(ctx context.Context, req *pb.AddMissingTicketRequest) (*pb.AddMissingTicketResponse, error) {
 	err := s.appContext.AddMissingTicket(req.Hash)
 	if err != nil {