Add low level rpc to sign taproot inputs (#61)

* Add internal support for schnorr signing

* Update deps

* Update protos and interface layer

* Fixes after review

* Fixes (#2)

* pair programming fixes

* fix prevouts assets, values and scripts

* Fixes

* Update deps

* Fixes

* Update deps

---------

Co-authored-by: Louis Singer <41042567+louisinger@users.noreply.github.com>

api-spec/protobuf/ocean/v1/transaction.proto

@@ -49,7 +49,6 @@ service TransactionService {
 
   // Transfer returns a transaction to send funds to some receiver.
   rpc Transfer(TransferRequest) returns (TransferResponse);
-
 
   // PegInAddress returns what's necessary to peg funds of the Bitcoin 
   // main-chain and have them available on the Liquid side-chain.
@@ -61,6 +60,10 @@ service TransactionService {
   // ClaimPegIn returns a transaction to claim funds pegged on the Bitcoin 
   // main-chain to have them available on the Liquid side-chain.
   rpc ClaimPegIn(ClaimPegInRequest) returns (ClaimPegInResponse);
+
+  // SignPsetWithSchnorrKey signs all taproot inputs of the provided tx with
+  // the key at the given derivation path.
+  rpc SignPsetWithSchnorrKey(SignPsetWithSchnorrKeyRequest) returns (SignPsetWithSchnorrKeyResponse);
 }
 
 message GetTransactionRequest{
@@ -261,4 +264,15 @@ message ClaimPegInRequest{
 message ClaimPegInResponse{
   // Signed tx in hex format.
   string tx_hex = 1;
+}
+
+message SignPsetWithSchnorrKeyRequest {
+  // The partial transaction to sign in base64 format.
+  string tx = 1;
+  // The sighash type. SIGHASH_DEFAULT is used for any input that does not specify one.
+  uint32 sighash_type = 2;
+}
+
+message SignPsetWithSchnorrKeyResponse {
+  string signed_tx = 1;
 }

go.mod

@@ -19,7 +19,7 @@ require (
 	github.com/stretchr/testify v1.8.1
 	github.com/timshannon/badgerhold/v4 v4.0.2
 	github.com/vulpemventures/go-bip39 v1.0.2
-	github.com/vulpemventures/go-elements v0.5.1
+	github.com/vulpemventures/go-elements v0.5.3
 	github.com/vulpemventures/neutrino-elements v0.1.3
 	golang.org/x/crypto v0.1.0
 	golang.org/x/net v0.7.0
@@ -31,9 +31,12 @@ require (
 	github.com/jackc/pgconn v1.12.1
 	github.com/jackc/pgx/v4 v4.16.1
 	github.com/tyler-smith/go-bip39 v1.1.0
+	github.com/vulpemventures/go-bip32 v0.0.0-20200624192635-867c159da4d7
 )
 
 require (
+	github.com/FactomProject/basen v0.0.0-20150613233007-fe3947df716e // indirect
+	github.com/FactomProject/btcutilecc v0.0.0-20130527213604-d3a63a5752ec // indirect
 	github.com/aead/siphash v1.0.1 // indirect
 	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/btcsuite/btcd/btcutil/psbt v1.1.4 // indirect

go.sum

@@ -78,6 +78,10 @@ github.com/Azure/go-autorest/tracing v0.6.0/go.mod h1:+vhtPC754Xsa23ID7GlGsrdKBp
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
 github.com/BurntSushi/xgb v0.0.0-20160522181843-27f122750802/go.mod h1:IVnqGOEym/WlBOVXweHU+Q+/VP0lqqI8lqeDx9IjBqo=
 github.com/ClickHouse/clickhouse-go v1.4.3/go.mod h1:EaI/sW7Azgz9UATzd5ZdZHRUhHgv5+JMS9NSr2smCJI=
+github.com/FactomProject/basen v0.0.0-20150613233007-fe3947df716e h1:ahyvB3q25YnZWly5Gq1ekg6jcmWaGj/vG/MhF4aisoc=
+github.com/FactomProject/basen v0.0.0-20150613233007-fe3947df716e/go.mod h1:kGUqhHd//musdITWjFvNTHn90WG9bMLBEPQZ17Cmlpw=
+github.com/FactomProject/btcutilecc v0.0.0-20130527213604-d3a63a5752ec h1:1Qb69mGp/UtRPn422BH4/Y4Q3SLUrD9KHuDkm8iodFc=
+github.com/FactomProject/btcutilecc v0.0.0-20130527213604-d3a63a5752ec/go.mod h1:CD8UlnlLDiqb36L110uqiP2iSflVjx9g/3U9hCI4q2U=
 github.com/Masterminds/semver/v3 v3.1.1/go.mod h1:VPu/7SZ7ePZ3QOrcuXROw5FAcLl4a0cBrbBpGY/8hQs=
 github.com/Microsoft/go-winio v0.4.11/go.mod h1:VhR8bwka0BXejwEJY73c50VrPtXAaKcyvVC4A4RozmA=
 github.com/Microsoft/go-winio v0.4.14/go.mod h1:qXqCSQ3Xa7+6tgxaGTIe4Kpcdsi+P8jBhyzoq1bpyYA=
@@ -230,6 +234,8 @@ github.com/cilium/ebpf v0.6.2/go.mod h1:4tRaxcgiL706VnOzHOdBlY8IEAIdxINsQBcU4xJJ
 github.com/cilium/ebpf v0.7.0/go.mod h1:/oI2+1shJiTGAMgl6/RgJr36Eo1jzrRcAWbcXO2usCA=
 github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDkc90ppPyw=
 github.com/cloudflare/golz4 v0.0.0-20150217214814-ef862a3cdc58/go.mod h1:EOBUe0h4xcZ5GoxqC5SDxFQ8gwyZPKQoEzownBlhI80=
+github.com/cmars/basen v0.0.0-20150613233007-fe3947df716e h1:0XBUw73chJ1VYSsfvcPvVT7auykAJce9FpRr10L6Qhw=
+github.com/cmars/basen v0.0.0-20150613233007-fe3947df716e/go.mod h1:P13beTBKr5Q18lJe1rIoLUqjM+CB1zYrRg44ZqGuQSA=
 github.com/cncf/udpa/go v0.0.0-20191209042840-269d4d468f6f/go.mod h1:M8M6+tZqaGXZJjfX53e64911xZQV5JYwmTeXPW+k8Sc=
 github.com/cncf/udpa/go v0.0.0-20200629203442-efcf912fb354/go.mod h1:WmhPx2Nbnhtbo57+VJT5O0JRkEi1Wbu0z5j0R8u5Hbk=
 github.com/cncf/udpa/go v0.0.0-20201120205902-5459f2c99403/go.mod h1:WmhPx2Nbnhtbo57+VJT5O0JRkEi1Wbu0z5j0R8u5Hbk=
@@ -1154,6 +1160,7 @@ github.com/stretchr/objx v0.4.0/go.mod h1:YvHI0jy2hoMjB+UWwv71VJQ9isScKT/TqJzVSS
 github.com/stretchr/objx v0.5.0 h1:1zr/of2m5FGMsad5YfcqgdqdWrIhu+EBEJRhR1U7z/c=
 github.com/stretchr/objx v0.5.0/go.mod h1:Yh+to48EsGEfYuaHDzXPcE3xhTkx73EhmCGUpEOglKo=
 github.com/stretchr/testify v0.0.0-20180303142811-b89eecf5ca5d/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
+github.com/stretchr/testify v1.1.5-0.20170601210322-f6abca593680/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
@@ -1199,10 +1206,12 @@ github.com/vishvananda/netns v0.0.0-20200728191858-db3c7e526aae/go.mod h1:DD4vA1
 github.com/vishvananda/netns v0.0.0-20210104183010-2eb08e3e575f/go.mod h1:DD4vA1DwXk04H54A1oHXtwZmA0grkVMdPxx/VGLCah0=
 github.com/vulpemventures/fastsha256 v0.0.0-20160815193821-637e65642941 h1:CTcw80hz/Sw8hqlKX5ZYvBUF5gAHSHwdjXxRf/cjDcI=
 github.com/vulpemventures/fastsha256 v0.0.0-20160815193821-637e65642941/go.mod h1:GXBJykxW2kUcktGdsgyay7uwwWvkljASfljNcT0mbh8=
+github.com/vulpemventures/go-bip32 v0.0.0-20200624192635-867c159da4d7 h1:X7DtNv+YWy76kELMZB/xVkIJ7YNp2vpgMFVsDcQA40U=
+github.com/vulpemventures/go-bip32 v0.0.0-20200624192635-867c159da4d7/go.mod h1:Zrvx8XgpWvSPdz1lXnuN083CkoZnzwxBLEB03S8et1I=
 github.com/vulpemventures/go-bip39 v1.0.2 h1:+BgKOVo04okKf1wA4Fhv8ccvql+qFyzVUdVJKkb48r0=
 github.com/vulpemventures/go-bip39 v1.0.2/go.mod h1:mjFmuv9D6BtANI6iscMmbHhmBOwjMCFfny3mxHnuDrk=
-github.com/vulpemventures/go-elements v0.5.1 h1:F83n7dScOnAnpyH9VgWLdC68Qcva+2EWVzzNuW2UKak=
-github.com/vulpemventures/go-elements v0.5.1/go.mod h1:aBGuWXHaiAIUIcwqCdtEh2iQ3kJjKwHU9ywvhlcRSeU=
+github.com/vulpemventures/go-elements v0.5.3 h1:zaC/ynHFwCAzFSOMfzb6BcbD6FXASppSiGMycc95WVA=
+github.com/vulpemventures/go-elements v0.5.3/go.mod h1:aBGuWXHaiAIUIcwqCdtEh2iQ3kJjKwHU9ywvhlcRSeU=
 github.com/vulpemventures/go-secp256k1-zkp v1.1.6 h1:BmsrmXRLUibwa75Qkk8yELjpzCzlAjYFGLiLiOdq7Xo=
 github.com/vulpemventures/go-secp256k1-zkp v1.1.6/go.mod h1:zo7CpgkuPgoe7fAV+inyxsI9IhGmcoFgyD8nqZaPSOM=
 github.com/vulpemventures/neutrino-elements v0.1.3 h1:rzg6G1oL2fWodOZ716SOs71JuqttPCjjmig7TrlHrxM=
@@ -1291,6 +1300,7 @@ go.uber.org/zap v1.9.1/go.mod h1:vwi/ZaCAaUcBkycHslxD9B2zi4UTXhF60s6SWpuDF0Q=
 go.uber.org/zap v1.10.0/go.mod h1:vwi/ZaCAaUcBkycHslxD9B2zi4UTXhF60s6SWpuDF0Q=
 go.uber.org/zap v1.13.0/go.mod h1:zwrFLgMcdUuIBviXEYEH1YKNaOBnKXsx2IPda5bBwHM=
 go.uber.org/zap v1.17.0/go.mod h1:MXVU+bhUf/A7Xi2HNOnopQOrmycQ5Ih87HtOu4q5SSo=
+golang.org/x/crypto v0.0.0-20170613210332-850760c427c5/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/crypto v0.0.0-20170930174604-9419663f5a44/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/crypto v0.0.0-20171113213409-9f005a07e0d3/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/crypto v0.0.0-20180904163835-0709b304e793/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
@@ -1979,6 +1989,8 @@ k8s.io/kubernetes v1.13.0/go.mod h1:ocZa8+6APFNC2tX1DZASIbocyYT5jHzqFVsY5aoB7Jk=
 k8s.io/utils v0.0.0-20201110183641-67b214c5f920/go.mod h1:jPW/WVKK9YHAvNhRxK0md/EJ228hCsBRufyofKtW8HA=
 k8s.io/utils v0.0.0-20210819203725-bdf08cb9a70a/go.mod h1:jPW/WVKK9YHAvNhRxK0md/EJ228hCsBRufyofKtW8HA=
 k8s.io/utils v0.0.0-20210930125809-cb0fa318a74b/go.mod h1:jPW/WVKK9YHAvNhRxK0md/EJ228hCsBRufyofKtW8HA=
+launchpad.net/gocheck v0.0.0-20140225173054-000000000087 h1:Izowp2XBH6Ya6rv+hqbceQyw/gSGoXfH/UPoTGduL54=
+launchpad.net/gocheck v0.0.0-20140225173054-000000000087/go.mod h1:hj7XX3B/0A+80Vse0e+BUHsHMTEhd0O4cpUHr/e/BUM=
 modernc.org/b v1.0.0/go.mod h1:uZWcZfRj1BpYzfN9JTerzlNUnnPsV9O2ZA8JsRcubNg=
 modernc.org/cc/v3 v3.32.4/go.mod h1:0R6jl1aZlIl2avnYfbfHBS1QB6/f+16mihBObaBC878=
 modernc.org/ccgo/v3 v3.9.2/go.mod h1:gnJpy6NIVqkETT+L5zPsQFj7L2kkhfPMzOghRNv/CFo=

internal/core/application/transaction_service.go

@@ -1,14 +1,18 @@
 package application
 
 import (
+	"bytes"
 	"context"
+	"encoding/binary"
 	"encoding/hex"
 	"fmt"
 	"math"
+	"strings"
 	"time"
 
 	"github.com/btcsuite/btcd/txscript"
 	log "github.com/sirupsen/logrus"
+	"github.com/vulpemventures/go-bip32"
 	"github.com/vulpemventures/go-elements/address"
 	"github.com/vulpemventures/go-elements/elementsutil"
 	"github.com/vulpemventures/go-elements/network"
@@ -636,6 +640,87 @@ func (ts *TransactionService) Transfer(
 	return txHex, nil
 }
 
+func (ts *TransactionService) SignPsetWithSchnorrKey(
+	ctx context.Context, tx string, sighashType uint32,
+) (string, error) {
+	wallet, err := ts.repoManager.WalletRepository().GetWallet(ctx)
+	if err != nil {
+		return "", err
+	}
+	mnemonic, err := wallet.GetMnemonic()
+	if err != nil {
+		return "", err
+	}
+	ssWallet, err := singlesig.NewWalletFromMnemonic(singlesig.NewWalletFromMnemonicArgs{
+		RootPath: wallet.RootPath,
+		Mnemonic: mnemonic,
+	})
+	if err != nil {
+		return "", err
+	}
+
+	ptx, err := psetv2.NewPsetFromBase64(tx)
+	if err != nil {
+		return "", err
+	}
+	if len(ptx.Global.Xpubs) < 1 {
+		return "", fmt.Errorf("missing pset global xpubs")
+	}
+
+	// For each global xpub, retrieve account info if it belongs to the wallet.
+	// Account info are required to know its derivation index, used later.
+	xpubsInfo := make([]struct {
+		account *domain.Account
+		xpub    *bip32.Key
+	}, 0, len(ptx.Global.Xpubs))
+	for _, xpub := range ptx.Global.Xpubs {
+		for _, account := range wallet.Accounts {
+			hdNode, err := bip32.B58Deserialize(account.Xpub)
+			if err != nil {
+				return "", err
+			}
+			accountXpub, err := hdNode.Serialize()
+			if err != nil {
+				return "", err
+			}
+
+			if bytes.Equal(xpub.ExtendedKey, accountXpub[:len(accountXpub)-4]) {
+				xpubsInfo = append(xpubsInfo, struct {
+					account *domain.Account
+					xpub    *bip32.Key
+				}{account, hdNode})
+				break
+			}
+		}
+	}
+
+	// For each input that has a taproot bip32 derivation field,
+	// construct the derivation path by attaching the bip32 derivation to the
+	// account's index. This derivation path format is needed by the signing wallet.
+	derivationPathMap := make(map[string]string)
+	for _, in := range ptx.Inputs {
+		for _, derivation := range in.TapBip32Derivation {
+			for _, info := range xpubsInfo {
+				if derivation.MasterKeyFingerprint == binary.LittleEndian.Uint32(info.xpub.FingerPrint) {
+					derivationPath := []string{fmt.Sprintf("%d'", info.account.Index)}
+					for _, step := range derivation.Bip32Path {
+						derivationPath = append(derivationPath, fmt.Sprintf("%d", step))
+					}
+					derivationPathMap[hex.EncodeToString(in.GetUtxo().Script)] = strings.Join(derivationPath, "/")
+					break
+				}
+			}
+		}
+	}
+
+	return ssWallet.SignTaproot(singlesig.SignTaprootArgs{
+		PsetBase64:        tx,
+		DerivationPathMap: derivationPathMap,
+		GenesisBlockHash:  ts.network.GenesisBlockHash,
+		SighashType:       txscript.SigHashType(sighashType),
+	})
+}
+
 func (ts *TransactionService) registerHandlerForWalletEvents() {
 	ts.repoManager.RegisterHandlerForWalletEvent(
 		domain.WalletUnlocked, func(_ domain.WalletEvent) {

internal/infrastructure/blockchain-scanner/electrum/tcp_client.go

@@ -245,6 +245,7 @@ func (c *tcpClient) unsubscribeForAccount(accountName string) {
 	// 	c.unsubscribeForScript(accountName, scriptHash)
 	// }
 	c.chHandler.clearAccount(accountName)
+	delete(c.reportHandlers, accountName)
 }
 
 func (c *tcpClient) subscribeForScripts(

internal/infrastructure/blockchain-scanner/electrum/ws_client.go

@@ -216,6 +216,7 @@ func (c *wsClient) unsubscribeForAccount(accountName string) {
 	// 	c.unsubscribeForScript(accountName, scriptHash)
 	// }
 	c.chHandler.clearAccount(accountName)
+	delete(c.reportHandlers, accountName)
 }
 
 func (c *wsClient) getScriptHashesHistory(scriptHashes []string) (map[string][]txInfo, error) {

internal/interfaces/grpc/handler/transaction.go

@@ -262,6 +262,26 @@ func (t *transaction) ClaimPegIn(
 	return nil, fmt.Errorf("to be implemented")
 }
 
+func (t *transaction) SignPsetWithSchnorrKey(
+	ctx context.Context, req *pb.SignPsetWithSchnorrKeyRequest,
+) (*pb.SignPsetWithSchnorrKeyResponse, error) {
+	tx, err := parsePset(req.GetTx())
+	if err != nil {
+		return nil, status.Error(codes.InvalidArgument, err.Error())
+	}
+
+	signedTx, err := t.appSvc.SignPsetWithSchnorrKey(
+		ctx, tx, req.GetSighashType(),
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	return &pb.SignPsetWithSchnorrKeyResponse{
+		SignedTx: signedTx,
+	}, nil
+}
+
 func validateTxid(txid string) error {
 	if txid == "" {
 		return fmt.Errorf("missing txid")