- exported NewBLSignature

- addded Transaction.PutSignature

dapps/valuetransfers/packages/address/signaturescheme/bls.go

@@ -95,7 +95,7 @@ func (sigscheme *blsSignatureScheme) Sign(data []byte) Signature {
 	if err != nil {
 		panic(err)
 	}
-	return newBLSSignature(pubKeyBin, sig)
+	return NewBLSSignature(pubKeyBin, sig)
 }
 
 func (sigscheme *blsSignatureScheme) String() string {
@@ -136,7 +136,7 @@ func BLSSignatureFromBytes(data []byte) (result *BLSSignature, consumedBytes int
 	return
 }
 
-func newBLSSignature(pubKey, signature []byte) *BLSSignature {
+func NewBLSSignature(pubKey, signature []byte) *BLSSignature {
 	var ret BLSSignature
 	ret[0] = address.VersionBLS
 	copy(ret.pubKey(), pubKey)
@@ -223,7 +223,7 @@ func AggregateBLSSignatures(sigs ...Signature) (Signature, error) {
 	if err != nil {
 		return nil, err
 	}
-	return newBLSSignature(pubKeyBin, sigBin), nil
+	return NewBLSSignature(pubKeyBin, sigBin), nil
 }
 
 // interface contract (allow the compiler to check if the implementation has all of the required methods).

dapps/valuetransfers/packages/transaction/transaction.go

 package transaction
 
 import (
+	"errors"
 	"fmt"
 	"sync"
 
@@ -279,6 +280,16 @@ func (transaction *Transaction) Sign(signature signaturescheme.SignatureScheme)
 	return transaction
 }
 
+// PutSignature validates and adds signature to the transaction
+func (transaction *Transaction) PutSignature(signature signaturescheme.Signature) error {
+	if !signature.IsValid(transaction.EssenceBytes()) {
+		return errors.New("PutSignature: invalid signature")
+	}
+	transaction.signatures.Add(signature.Address(), signature)
+
+	return nil
+}
+
 // String returns a human readable version of this Transaction (for debug purposes).
 func (transaction *Transaction) String() string {
 	id := transaction.ID()

dapps/valuetransfers/packages/transaction/transaction_test.go

@@ -124,3 +124,69 @@ func TestMarshalingDataPayload(t *testing.T) {
 
 	assert.Equal(t, true, bytes.Equal(tx1.ID().Bytes(), tx.ID().Bytes()))
 }
+
+func TestPutSignatureValid(t *testing.T) {
+	sigScheme := signaturescheme.RandBLS()
+	addr := sigScheme.Address()
+	o1 := NewOutputID(addr, RandomID())
+	inputs := NewInputs(o1)
+	bal := balance.New(balance.ColorIOTA, 1)
+	outputs := NewOutputs(map[address.Address][]*balance.Balance{addr: {bal}})
+	tx := New(inputs, outputs)
+
+	dataPayload := []byte("data payload test")
+	err := tx.SetDataPayload(dataPayload)
+	assert.Equal(t, nil, err)
+
+	signature := sigScheme.Sign(tx.EssenceBytes())
+	assert.Equal(t, signature.IsValid(tx.EssenceBytes()), true)
+
+	err = tx.PutSignature(signature)
+	assert.Equal(t, nil, err)
+
+	check := tx.SignaturesValid()
+	assert.Equal(t, true, check)
+}
+
+func TestPutSignatureInvalid(t *testing.T) {
+	sigScheme := signaturescheme.RandBLS()
+	addr := sigScheme.Address()
+	o1 := NewOutputID(addr, RandomID())
+	inputs := NewInputs(o1)
+	bal := balance.New(balance.ColorIOTA, 1)
+	outputs := NewOutputs(map[address.Address][]*balance.Balance{addr: {bal}})
+	tx := New(inputs, outputs)
+
+	dataPayload := []byte("data payload test")
+	err := tx.SetDataPayload(dataPayload)
+	assert.Equal(t, nil, err)
+
+	signatureValid := sigScheme.Sign(tx.EssenceBytes())
+	assert.Equal(t, true, signatureValid.IsValid(tx.EssenceBytes()))
+
+	sigBytes := make([]byte, len(signatureValid.Bytes()))
+	copy(sigBytes, signatureValid.Bytes())
+	// inverse last byte --> corrupt the signatureValid
+	sigBytes[len(sigBytes)-1] = sigBytes[len(sigBytes)-1] ^ sigBytes[len(sigBytes)-1]
+
+	sigCorrupted, consumed, err := signaturescheme.BLSSignatureFromBytes(sigBytes)
+
+	assert.Equal(t, nil, err)
+	assert.Equal(t, consumed, len(sigBytes))
+	assert.Equal(t, false, sigCorrupted.IsValid(tx.EssenceBytes()))
+
+	err = tx.PutSignature(sigCorrupted)
+	// error expected
+	assert.Equal(t, true, err != nil)
+
+	// 0 signatures is not valid
+	assert.Equal(t, true, !tx.SignaturesValid())
+
+	err = tx.PutSignature(signatureValid)
+	// no error expected
+	assert.Equal(t, nil, err)
+
+	// valid signatures expected
+	assert.Equal(t, true, tx.SignaturesValid())
+
+}