Add support for asset re-issuance + Refactor tests (#145)

* Retrieve network for address within DecodeType

* Add support for reissuance

* Fix AddIssuance method and Add AddReissuance

* Fix blinder to correctly blind also reissuance txs

* Refactor tests:
* Add unique test for blinded issuance and reissuance
* Remove nonsense test
* Add more tests
* Increase readibility

* Make elementsutil importable

address/address.go

@@ -312,7 +312,7 @@ func FromConfidential(address string) (*ConfidentialAddress, error) {
 		return nil, err
 	}
 
-	addressType, err := DecodeType(address, *net)
+	addressType, err := DecodeType(address)
 	if err != nil {
 		return nil, err
 	}
@@ -414,8 +414,8 @@ func NetworkForAddress(address string) (*network.Network, error) {
 
 //ToOutputScript creates a new script to pay a transaction output to a the
 //specified address
-func ToOutputScript(address string, net network.Network) ([]byte, error) {
-	addressType, err := DecodeType(address, net)
+func ToOutputScript(address string) ([]byte, error) {
+	addressType, err := DecodeType(address)
 	if err != nil {
 		return nil, err
 	}
@@ -494,6 +494,7 @@ func ToOutputScript(address string, net network.Network) ([]byte, error) {
 	}
 }
 
+// GetScriptType returns the type of the given script (p2pkh, p2sh, etc.)
 func GetScriptType(script []byte) int {
 	switch script[0] {
 	case txscript.OP_0:
@@ -511,26 +512,38 @@ func GetScriptType(script []byte) int {
 }
 
 //DecodeType returns address type
-func DecodeType(address string, net network.Network) (int, error) {
-	if isBlech32(address, net) {
-		return decodeBlech32(address, net)
+func DecodeType(address string) (int, error) {
+	net, err := NetworkForAddress(address)
+	if err != nil {
+		return -1, err
+	}
+
+	if isBlech32(address, *net) {
+		return decodeBlech32(address, *net)
 	}
-	if isBech32(address, net) {
-		return decodeBech32(address, net)
+	if isBech32(address, *net) {
+		return decodeBech32(address, *net)
 	}
-	return decodeBase58(address, net)
+	return decodeBase58(address, *net)
 }
 
-func isBlech32(address string, net network.Network) bool {
-	oneIndex := strings.LastIndexByte(address, '1')
-	if oneIndex > 1 {
-		prefix := address[:oneIndex]
-		if prefix == net.Blech32 {
-			return true
-		}
-		return false
+// IsConfidential checks whether the given address is confidential
+func IsConfidential(address string) (bool, error) {
+	addressType, err := DecodeType(address)
+	if err != nil {
+		return false, err
 	}
-	return false
+
+	isConfidential := (addressType == ConfidentialP2Pkh ||
+		addressType == ConfidentialP2Sh ||
+		addressType == ConfidentialP2Wpkh ||
+		addressType == ConfidentialP2Wsh)
+
+	return isConfidential, nil
+}
+
+func isBlech32(address string, net network.Network) bool {
+	return strings.HasPrefix(address, net.Blech32)
 }
 
 func decodeBlech32(address string, net network.Network) (int, error) {
@@ -549,15 +562,7 @@ func decodeBlech32(address string, net network.Network) (int, error) {
 }
 
 func isBech32(address string, net network.Network) bool {
-	oneIndex := strings.LastIndexByte(address, '1')
-	if oneIndex > 1 {
-		prefix := address[:oneIndex]
-		if prefix == net.Bech32 {
-			return true
-		}
-		return false
-	}
-	return false
+	return strings.HasPrefix(address, net.Bech32)
 }
 
 func decodeBech32(address string, net network.Network) (int, error) {

address/address_test.go

@@ -5,7 +5,6 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
-	"github.com/vulpemventures/go-elements/network"
 )
 
 func TestBase58(t *testing.T) {
@@ -102,53 +101,44 @@ func TestConfidential(t *testing.T) {
 func TestDecodeAddressType(t *testing.T) {
 	tests := []struct {
 		address      string
-		network      network.Network
 		expectedType int
 	}{
 		{
 			address:      "Q9863Eah5byyxdBX8zghpooS2x4Ey8XZyc",
-			network:      network.Liquid,
 			expectedType: P2Pkh,
 		},
 		{
 			address:      "H5RCjtzndKyzFnVe41yg62T3WViWguyz4M",
-			network:      network.Liquid,
 			expectedType: P2Sh,
 		},
 		{
 			address:      "ex1qlg343tpldc4wvjxn3jdq2qs35r8j5yd5vqrmu3",
-			network:      network.Liquid,
 			expectedType: P2Wpkh,
 		},
 		{
 			address:      "ert1q2z45rh444qmeand48lq0wp3jatxs2nzh492ds9s5yscv2pplxwesajz7q3",
-			network:      network.Regtest,
 			expectedType: P2Wsh,
 		},
 		{
 			address:      "VTpuLYhJwE8CFm6h1A6DASCaJuRQqkBt6qGfbebSHAUxGXsJMo8wtRvLZYZSWWXt89jG55pCF4YfxMjh",
-			network:      network.Liquid,
 			expectedType: ConfidentialP2Pkh,
 		},
 		{
 			address:      "VJLDHFUbw8oPUcwzmf9jw4tZdN57rEfAusRmWy6knHAF2a4rLGenJz5WPVuyggVzQPHY6JjzKuw31B6e",
-			network:      network.Liquid,
 			expectedType: ConfidentialP2Sh,
 		},
 		{
 			address:      "lq1qqwrdmhm69vsq3qfym06tlyhfze9ltauay9tv4r34ueplfwtjx0q27dk2c4d3a9ms6wum04efclqph7dg4unwcmwmw4vnqreq3",
-			network:      network.Liquid,
 			expectedType: ConfidentialP2Wpkh,
 		},
 		{
 			address:      "lq1qq2akvug2el2rg6lt6aewh9rzy7dglf9ajdmrkknnwwl3jwxgfkh985x3lrzmrq2mc3c6aa85wgxxfm9v8r062qwq4ty579p54pn2q2hqnhgwv394ycf8",
-			network:      network.Liquid,
 			expectedType: ConfidentialP2Wsh,
 		},
 	}
 
 	for _, tt := range tests {
-		addressType, err := DecodeType(tt.address, tt.network)
+		addressType, err := DecodeType(tt.address)
 		if err != nil {
 			t.Fatal(err)
 		}

confidential/confidential.go

@@ -238,14 +238,14 @@ func unblindIssuance(
 	if len(blindKeys) <= 1 {
 		return nil, errors.New("missing asset blind private key")
 	}
-	if in.Issuance == nil {
+	if !in.HasAnyIssuance() {
 		return nil, errors.New("missing input issuance")
 	}
-	if len(in.IssuanceRangeProof) <= 0 {
+	if !in.HasConfidentialIssuance() {
 		return nil, errors.New("missing asset range proof")
 	}
 
-	if len(in.Issuance.TokenAmount) > 0 {
+	if in.Issuance.HasTokenAmount() {
 		if len(in.InflationRangeProof) <= 0 {
 			return nil, errors.New("missing token range proof")
 		}
@@ -267,7 +267,7 @@ func unblindIssuance(
 			Script:     make([]byte, 0),
 		},
 	}
-	if len(in.Issuance.TokenAmount) > 0 {
+	if in.Issuance.HasTokenAmount() {
 		token, err := calcTokenHash(in)
 		if err != nil {
 			return nil, err

doc.go

@@ -35,14 +35,14 @@ The input we just funded from the faucet and three outputs.
 
 One for the ammount we want to send, one for the change and a last one for the fee.
 	txInputHash, _ := hex.DecodeString(utxos[0]["txid"].(string))
-	txInputHash = bufferutil.ReverseBytes(txInputHash)
+	txInputHash = elementsutil.ReverseBytes(txInputHash)
 	txInputIndex := uint32(utxos[0]["vout"].(float64))
 	txInput := transaction.NewTxInput(txInputHash, txInputIndex)
 
 	lbtc, _ := hex.DecodeString(
 		"5ac9f65c0efcc4775e0baec4ec03abdde22473cd3cf33c0419ca290e0751b225",
 	)
-	lbtc = append([]byte{0x01}, bufferutil.ReverseBytes(lbtc)...)
+	lbtc = append([]byte{0x01}, elementsutil.ReverseBytes(lbtc)...)
 	receiverValue, _ := confidential.SatoshiToElementsValue(60000000)
 	receiverScript, _ := hex.DecodeString("76a91439397080b51ef22c59bd7469afacffbeec0da12e88ac")
 	receiverOutput := transaction.NewTxOutput(lbtc, receiverValue[:], receiverScript)

internal/elementsutil/amount.go → elementsutil/elementsutil.go

@@ -15,7 +15,7 @@ func SatoshiToElementsValue(val uint64) ([]byte, error) {
 	if err := bufferutil.BinarySerializer.PutUint64(b, binary.LittleEndian, val); err != nil {
 		return nil, err
 	}
-	res := append([]byte{unconfPrefix}, bufferutil.ReverseBytes(b.Bytes())...)
+	res := append([]byte{unconfPrefix}, ReverseBytes(b.Bytes())...)
 	return res, nil
 }
 
@@ -27,7 +27,21 @@ func ElementsToSatoshiValue(val []byte) (uint64, error) {
 	if val[0] != byte(1) {
 		return 0, errors.New("invalid prefix")
 	}
-	reverseValueBuffer := bufferutil.ReverseBytes(val[1:])
+	reverseValueBuffer := ReverseBytes(val[1:])
 	d := bufferutil.NewDeserializer(bytes.NewBuffer(reverseValueBuffer))
 	return d.ReadUint64()
 }
+
+// ReverseBytes returns a copy of the given byte slice with elems in reverse order.
+func ReverseBytes(buf []byte) []byte {
+	if len(buf) < 1 {
+		return buf
+	}
+	tmp := make([]byte, len(buf))
+	copy(tmp, buf)
+	for i := len(tmp)/2 - 1; i >= 0; i-- {
+		j := len(tmp) - 1 - i
+		tmp[i], tmp[j] = tmp[j], tmp[i]
+	}
+	return tmp
+}

internal/bufferutil/bufferutil.go

@@ -289,17 +289,3 @@ func VarIntSerializeSize(val uint64) int {
 func VarSliceSerializeSize(val []byte) int {
 	return VarIntSerializeSize(uint64(len(val))) + len(val)
 }
-
-// ReverseBytes returns a copy of the given byte slice with elems in reverse order.
-func ReverseBytes(buf []byte) []byte {
-	if len(buf) < 1 {
-		return buf
-	}
-	tmp := make([]byte, len(buf))
-	copy(tmp, buf)
-	for i := len(tmp)/2 - 1; i >= 0; i-- {
-		j := len(tmp) - 1 - i
-		tmp[i], tmp[j] = tmp[j], tmp[i]
-	}
-	return tmp
-}

pset/blinder.go

@@ -7,7 +7,7 @@ import (
 
 	"github.com/btcsuite/btcd/btcec"
 	"github.com/vulpemventures/go-elements/confidential"
-	"github.com/vulpemventures/go-elements/internal/elementsutil"
+	"github.com/vulpemventures/go-elements/elementsutil"
 	"github.com/vulpemventures/go-elements/transaction"
 )
 
@@ -180,9 +180,12 @@ func (b *blinder) unblindInputs() (
 
 		// if the current input contains an issuance, add the pseudo input to the
 		// returned unblindedPseudoIns array
-		if input.HasIssuance() {
-			issuance := transaction.NewTxIssuanceFromContractHash(input.Issuance.AssetEntropy)
-			issuance.GenerateEntropy(input.Hash, input.Index)
+		if input.HasAnyIssuance() {
+			issuance, err := transaction.NewTxIssuanceFromInput(input)
+			if err != nil {
+				return nil, nil, err
+			}
+
 			asset, err := issuance.GenerateAsset()
 			if err != nil {
 				return nil, nil, err
@@ -211,9 +214,10 @@ func (b *blinder) unblindInputs() (
 
 			// if the token amount is not defined, it is set to 0x00, thus we need
 			// to check if the input.Issuance.TokenAmount, that is encoded in the
-			// elements format, contains more than one byte
-			if len(input.Issuance.TokenAmount) > 1 {
-				value, err := elementsutil.ElementsToSatoshiValue(input.Issuance.TokenAmount)
+			// elements format, contains more than one byte. We simply ignore the
+			// token amount for reissuances.
+			if i := input.Issuance; !i.IsReissuance() && i.HasTokenAmount() {
+				value, err := elementsutil.ElementsToSatoshiValue(i.TokenAmount)
 				if err != nil {
 					return nil, nil, err
 				}
@@ -225,9 +229,7 @@ func (b *blinder) unblindInputs() (
 					tokenFlag = 0
 				}
 
-				token, err := issuance.GenerateReissuanceToken(
-					tokenFlag,
-				)
+				token, err := issuance.GenerateReissuanceToken(tokenFlag)
 				if err != nil {
 					return nil, nil, err
 				}
@@ -320,23 +322,20 @@ func (b *blinder) blindInputs(unblinded []confidential.UnblindOutputResult) erro
 
 	getBlindingFactors := func(asset []byte) ([]byte, []byte, error) {
 		for _, u := range unblinded {
-			if bytes.Compare(asset, u.Asset) == 0 {
+			if bytes.Equal(asset, u.Asset) {
 				return u.ValueBlindingFactor, u.AssetBlindingFactor, nil
 			}
 		}
 		return nil, nil, errors.New("no blinding factors generated for pseudo issuance inputs")
 	}
 
 	for index, input := range b.pset.UnsignedTx.Inputs {
-		if input.HasIssuance() {
-			issuance := transaction.NewTxIssuanceFromContractHash(
-				input.Issuance.AssetEntropy,
-			)
-
-			err := issuance.GenerateEntropy(input.Hash, input.Index)
+		if input.HasAnyIssuance() {
+			issuance, err := transaction.NewTxIssuanceFromInput(input)
 			if err != nil {
 				return err
 			}
+
 			asset, err := issuance.GenerateAsset()
 			if err != nil {
 				return err
@@ -352,10 +351,12 @@ func (b *blinder) blindInputs(unblinded []confidential.UnblindOutputResult) erro
 				return err
 			}
 
-			// if the token amount is not defined, it is set to 0x00, thus we need
-			// to check if the input.Issuance.TokenAmount, that is encoded in the
-			// elements format, contains more than one byte
-			if len(input.Issuance.TokenAmount) > 1 {
+			// ONLY in case the issuance is not a reissuance, if the token amount is
+			// not defined, it is set to 0x00, thus it's required to check that the
+			// input.Issuance.TokenAmount, that's encoded in the elements format (!),
+			// is longer than one byte. Reissuances, instead, cannot have a token
+			// amount defined.
+			if i := input.Issuance; !i.IsReissuance() && i.HasTokenAmount() {
 				token, err := issuance.GenerateReissuanceToken(
 					ConfidentialReissuanceTokenFlag,
 				)
@@ -686,7 +687,7 @@ func verifyBlinding(
 			inAssetBlinders = append(inAssetBlinders, unblinded.AssetBlindingFactor)
 		}
 
-		if txIn := pset.UnsignedTx.Inputs[i]; txIn.HasIssuance() {
+		if txIn := pset.UnsignedTx.Inputs[i]; txIn.HasAnyIssuance() {
 			if txIn.HasConfidentialIssuance() {
 				unblinded, err := confidential.UnblindIssuance(txIn, inIssuanceKeys[i].ToSlice())
 				if err != nil {
@@ -698,7 +699,7 @@ func verifyBlinding(
 					unblinded.Asset.AssetBlindingFactor,
 				)
 
-				if len(txIn.Issuance.TokenAmount) > 0 {
+				if txIn.Issuance.HasTokenAmount() {
 					inIssuanceAssets = append(inIssuanceAssets, unblinded.Token.Asset)
 					inIssuanceAssetBlinders = append(
 						inIssuanceAssetBlinders,
@@ -720,7 +721,7 @@ func verifyBlinding(
 					transaction.Zero[:],
 				)
 
-				if len(txIn.Issuance.TokenAmount) > 0 {
+				if txIn.Issuance.HasTokenAmount() {
 					token, err := iss.GenerateReissuanceToken(0)
 					if err != nil {
 						return false