func (t *Transaction) VerifyTransaction(pow []byte) bool {
headerHash := t.Hash()
payloadHash := helpers.SHA256(t.Payload)
return reflect.DeepEqual(payloadHash, t.Header.PayloadHash) && CheckProofOfWork(pow, headerHash) && SignatureVerify(t.Header.From, t.Signature, headerHash)
}
func (b *Block) GenerateMerkelRoot() []byte {
var merkell func(hashes [][]byte) []byte
merkell = func(hashes [][]byte) []byte {
l := len(hashes)
if l == 0 {
return nil
}
if l == 1 {
return hashes[0]
} else {
if l%2 == 1 {
return merkell([][]byte{merkell(hashes[:l-1]), hashes[l-1]})
}
bs := make([][]byte, l/2)
for i, _ := range bs {
j, k := i*2, (i*2)+1
bs[i] = helpers.SHA256(append(hashes[j], hashes[k]...))
}
return merkell(bs)
}
}
ts := functional.Map(func(t Transaction) []byte { return t.Hash() }, []Transaction(*b.TransactionSlice)).([][]byte)
return merkell(ts)
}
func TestMerkellHash(t *testing.T) {
tr1 := NewTransaction(nil, nil, []byte(helpers.RandomString(helpers.RandomInt(0, 1024*1024))))
tr2 := NewTransaction(nil, nil, []byte(helpers.RandomString(helpers.RandomInt(0, 1024*1024))))
tr3 := NewTransaction(nil, nil, []byte(helpers.RandomString(helpers.RandomInt(0, 1024*1024))))
tr4 := NewTransaction(nil, nil, []byte(helpers.RandomString(helpers.RandomInt(0, 1024*1024))))
b := new(Block)
b.TransactionSlice = &TransactionSlice{*tr1, *tr2, *tr3, *tr4}
mt := b.GenerateMerkelRoot()
manual := helpers.SHA256(append(helpers.SHA256(append(tr1.Hash(), tr2.Hash()...)), helpers.SHA256(append(tr3.Hash(), tr4.Hash()...))...))
if !reflect.DeepEqual(mt, manual) {
t.Error("Merkel tree generation fails")
}
}
// Returns bytes to be sent to the network
func NewTransaction(from, to, payload []byte) *Transaction {
t := Transaction{Header: TransactionHeader{From: from, To: to}, Payload: payload}
t.Header.Timestamp = uint32(time.Now().Unix())
t.Header.PayloadHash = helpers.SHA256(t.Payload)
t.Header.PayloadLength = uint32(len(t.Payload))
return &t
}
func TestKeySigning(t *testing.T) {
for i := 0; i < 5; i++ {
keypair := GenerateNewKeypair()
data := helpers.ArrayOfBytes(i, 'a')
hash := helpers.SHA256(data)
signature, err := keypair.Sign(hash)
if err != nil {
t.Error("base58 error")
} else if !SignatureVerify(keypair.Public, signature, hash) {
t.Error("Signing and verifying error", len(keypair.Public))
}
}
}
func (t *Transaction) Hash() []byte {
headerBytes, _ := t.Header.MarshalBinary()
return helpers.SHA256(headerBytes)
}
func (b *Block) Hash() []byte {
headerHash, _ := b.BlockHeader.MarshalBinary()
return helpers.SHA256(headerHash)
}