add /feeaddress (#3)

go.mod

@@ -4,6 +4,7 @@ go 1.13
 
 require (
 	decred.org/dcrwallet v1.2.3-0.20200507155221-397dd551e317
+	github.com/decred/dcrd/blockchain/stake/v3 v3.0.0-20200311044114-143c1884e4c8
 	github.com/decred/dcrd/chaincfg/chainhash v1.0.2
 	github.com/decred/dcrd/chaincfg/v3 v3.0.0-20200511175520-d08cb3f72b3b
 	github.com/decred/dcrd/dcrec v1.0.0

go.sum

@@ -19,6 +19,7 @@ github.com/decred/base58 v1.0.2/go.mod h1:pXP9cXCfM2sFLb2viz2FNIdeMWmZDBKG3ZBYbi
 github.com/decred/dcrd/addrmgr v1.1.0/go.mod h1:exghL+0+QeVvO4MXezWJ1C2tcpBn3ngfuP6S1R+adB8=
 github.com/decred/dcrd/blockchain/stake/v2 v2.0.2/go.mod h1:o2TT/l/YFdrt15waUdlZ3g90zfSwlA0WgQqHV9UGJF4=
 github.com/decred/dcrd/blockchain/stake/v3 v3.0.0-20200215031403-6b2ce76f0986/go.mod h1:aDL94kcVJfaaJP+acWUJrlK7g7xEOqTSiFe6bSN3yRQ=
+github.com/decred/dcrd/blockchain/stake/v3 v3.0.0-20200311044114-143c1884e4c8 h1:6oEo1yQYyfnT9qCERrLWMi9BlDzVBeyl011ssIAVQ3w=
 github.com/decred/dcrd/blockchain/stake/v3 v3.0.0-20200311044114-143c1884e4c8/go.mod h1:4zE60yDWlfCDtmqnyP5o1k1K0oyhNn3Tvqo6F93/+RU=
 github.com/decred/dcrd/blockchain/standalone v1.1.0 h1:yclvVGEY09Gf8A4GSAo+NCtL1dW2TYJ4OKp4+g0ICI0=
 github.com/decred/dcrd/blockchain/standalone v1.1.0/go.mod h1:6K8ZgzlWM1Kz2TwXbrtiAvfvIwfAmlzrtpA7CVPCUPE=
@@ -39,6 +40,7 @@ github.com/decred/dcrd/crypto/blake256 v1.0.0 h1:/8DMNYp9SGi5f0w7uCm6d6M4OU2rGFK
 github.com/decred/dcrd/crypto/blake256 v1.0.0/go.mod h1:sQl2p6Y26YV+ZOcSTP6thNdn47hh8kt6rqSlvmrXFAc=
 github.com/decred/dcrd/crypto/ripemd160 v1.0.0 h1:MciTnR4NfBqDFRFjFkrn8WPLP4Vo7t6ww6ghfn6wcXQ=
 github.com/decred/dcrd/crypto/ripemd160 v1.0.0/go.mod h1:F0H8cjIuWTRoixr/LM3REB8obcWkmYx0gbxpQWR8RPg=
+github.com/decred/dcrd/database/v2 v2.0.1 h1:ghLzkKpVpwvjrdRv3njrEfkvygQpYQX66sGVs8ha+E8=
 github.com/decred/dcrd/database/v2 v2.0.1/go.mod h1:ZOaWTv3IlNqCA+y7q3q5EozgmiDOmNwCSq3ntZn2CDo=
 github.com/decred/dcrd/dcrec v1.0.0 h1:W+z6Es+Rai3MXYVoPAxYr5U1DGis0Co33scJ6uH2J6o=
 github.com/decred/dcrd/dcrec v1.0.0/go.mod h1:HIaqbEJQ+PDzQcORxnqen5/V1FR3B4VpIfmePklt8Q8=

methods.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"context"
 	"crypto/ed25519"
+	"encoding/base64"
 	"encoding/binary"
 	"encoding/hex"
 	"encoding/json"
@@ -14,6 +15,7 @@ import (
 	"time"
 
 	"decred.org/dcrwallet/wallet/txrules"
+	"github.com/decred/dcrd/blockchain/stake/v3"
 	"github.com/decred/dcrd/chaincfg/chainhash"
 	"github.com/decred/dcrd/dcrec"
 	"github.com/decred/dcrd/dcrutil/v3"
@@ -52,6 +54,120 @@ func fee(c *gin.Context) {
 	}, http.StatusOK, c)
 }
 
+func feeAddress(c *gin.Context) {
+	// HTTP GET Params required
+	// ticketHash - hash of ticket
+	// signature - signmessage signature using the ticket commitment address
+	//           - message = "vsp v3 getfeeaddress ticketHash"
+
+	// ticketHash
+	ticketHashStr := c.Param("ticketHash")
+	if len(ticketHashStr) != chainhash.MaxHashStringSize {
+		c.AbortWithError(http.StatusBadRequest, errors.New("invalid ticket hash"))
+		return
+	}
+	txHash, err := chainhash.NewHashFromStr(ticketHashStr)
+	if err != nil {
+		c.AbortWithError(http.StatusBadRequest, errors.New("invalid ticket hash"))
+		return
+	}
+
+	// signature - sanity check signature is in base64 encoding
+	signature := c.Param("signature")
+	if _, err = base64.StdEncoding.DecodeString(signature); err != nil {
+		c.AbortWithError(http.StatusBadRequest, errors.New("invalid signature"))
+		return
+	}
+
+	// check DB for cached response
+	// TODO: check db
+
+	ctx := c.Request.Context()
+
+	var resp dcrdtypes.TxRawResult
+	err = nodeConnection.Call(ctx, "getrawtransaction", &resp, txHash.String(), true)
+	if err != nil {
+		c.AbortWithError(http.StatusBadRequest, errors.New("unknown transaction"))
+		return
+	}
+	if resp.Confirmations < 2 || resp.BlockHeight < 0 {
+		c.AbortWithError(http.StatusBadRequest, errors.New("transaction does not have minimum confirmations"))
+		return
+	}
+	if resp.Confirmations > int64(uint32(cfg.netParams.TicketMaturity)+cfg.netParams.TicketExpiry) {
+		c.AbortWithError(http.StatusBadRequest, errors.New("ticket has expired"))
+		return
+	}
+
+	msgHex, err := hex.DecodeString(resp.Hex)
+	if err != nil {
+		c.AbortWithError(http.StatusInternalServerError, errors.New("unable to decode transaction"))
+		return
+	}
+
+	msgTx := wire.NewMsgTx()
+	if err = msgTx.FromBytes(msgHex); err != nil {
+		c.AbortWithError(http.StatusInternalServerError, errors.New("failed to deserialize transaction"))
+		return
+	}
+	if !stake.IsSStx(msgTx) {
+		c.AbortWithError(http.StatusBadRequest, errors.New("transaction is not a ticket"))
+		return
+	}
+	if len(msgTx.TxOut) != 3 {
+		c.AbortWithError(http.StatusBadRequest, errors.New("invalid ticket"))
+		return
+	}
+
+	// Get commitment address
+	addr, err := stake.AddrFromSStxPkScrCommitment(msgTx.TxOut[1].PkScript, cfg.netParams)
+	if err != nil {
+		c.AbortWithError(http.StatusInternalServerError, errors.New("failed to get commitment address"))
+		return
+	}
+
+	// verify message
+	message := fmt.Sprintf("vsp v3 getfeeaddress %s", msgTx.TxHash())
+	var valid bool
+	err = nodeConnection.Call(ctx, "verifymessage", &valid, addr.Address(), signature, message)
+	if err != nil {
+		c.AbortWithError(http.StatusInternalServerError, errors.New("RPC server error"))
+		return
+	}
+	if !valid {
+		c.AbortWithError(http.StatusBadRequest, errors.New("invalid signature"))
+		return
+	}
+
+	// get blockheight and sdiff which is required by
+	// txrules.StakePoolTicketFee, and store them in the database
+	// for processing by payfee
+	var blockHeader dcrdtypes.GetBlockHeaderVerboseResult
+	err = nodeConnection.Call(ctx, "getblockheader", &blockHeader, resp.BlockHash, true)
+	if err != nil {
+		c.AbortWithError(http.StatusInternalServerError, errors.New("RPC server error"))
+		return
+	}
+	sDiff := blockHeader.SBits
+
+	var newAddress string
+	err = nodeConnection.Call(ctx, "getnewaddress", &newAddress, "fees")
+	if err != nil {
+		c.AbortWithError(http.StatusInternalServerError, errors.New("unable to generate fee address"))
+		return
+	}
+
+	// TODO: Insert into DB
+	_ = sDiff
+
+	sendJSONResponse(feeAddressResponse{
+		Timestamp:           time.Now().Unix(),
+		TicketHash:          txHash.String(),
+		CommitmentSignature: signature,
+		FeeAddress:          newAddress,
+	}, http.StatusOK, c)
+}
+
 func payFee(c *gin.Context) {
 	// HTTP GET Params required
 	// feeTx - serialized wire.MsgTx
@@ -194,7 +310,7 @@ findAddress:
 // PayFee2 is copied from the stakepoold implementation in #625
 func PayFee2(ctx context.Context, ticketHash *chainhash.Hash, votingWIF *dcrutil.WIF, feeTx *wire.MsgTx) (string, error) {
 	var resp dcrdtypes.TxRawResult
-	err := nodeConnection.Call(ctx, "getrawtransaction", &resp, ticketHash.String())
+	err := nodeConnection.Call(ctx, "getrawtransaction", &resp, ticketHash.String(), true)
 	if err != nil {
 		fmt.Printf("PayFee: getrawtransaction: %v", err)
 		return "", errors.New("RPC server error")

responses.go

@@ -10,7 +10,7 @@ type feeResponse struct {
 	Fee       float64 `json:"fee"`
 }
 
-type getFeeAddressResponse struct {
+type feeAddressResponse struct {
 	Timestamp           int64  `json:"timestamp"`
 	TicketHash          string `json:"ticketHash"`
 	CommitmentSignature string `json:"commitmentSignature"`

router.go

@@ -12,6 +12,7 @@ func newRouter() *gin.Engine {
 	api.Use()
 	{
 		router.GET("/fee", fee)
+		router.GET("/feeaddress", feeAddress)
 		router.GET("/pubkey", pubKey)
 		router.GET("/payfee", payFee)
 	}