Merge pull request #418 from nspcc-dev/various-verification-fixes2

Transaction verification fixes, interops and block verification. Fixes #12.

config/config.go

@@ -49,6 +49,10 @@ type (
 		StandbyValidators       []string  `yaml:"StandbyValidators"`
 		SeedList                []string  `yaml:"SeedList"`
 		SystemFee               SystemFee `yaml:"SystemFee"`
+		// Whether to verify received blocks.
+		VerifyBlocks bool `yaml:"VerifyBlocks"`
+		// Whether to verify transactions in received blocks.
+		VerifyTransactions bool `yaml:"VerifyTransactions"`
 	}
 
 	// SystemFee fees related to system.

config/protocol.mainnet.yml

@@ -27,6 +27,8 @@ ProtocolConfiguration:
     IssueTransaction: 500
     PublishTransaction: 500
     RegisterTransaction: 10000
+  VerifyBlocks: true
+  VerifyTransactions: false
 
 ApplicationConfiguration:
   DBConfiguration:

config/protocol.privnet.docker.four.yml

@@ -15,6 +15,8 @@ ProtocolConfiguration:
     IssueTransaction: 500
     PublishTransaction: 500
     RegisterTransaction: 10000
+  VerifyBlocks: true
+  VerifyTransactions: true
 
 ApplicationConfiguration:
   DBConfiguration:

config/protocol.privnet.docker.one.yml

@@ -12,6 +12,8 @@ ProtocolConfiguration:
     IssueTransaction: 500
     PublishTransaction: 500
     RegisterTransaction: 10000
+  VerifyBlocks: true
+  VerifyTransactions: true
 
 ApplicationConfiguration:
   DBConfiguration:

config/protocol.privnet.docker.three.yml

@@ -12,6 +12,8 @@ ProtocolConfiguration:
     IssueTransaction: 500
     PublishTransaction: 500
     RegisterTransaction: 10000
+  VerifyBlocks: true
+  VerifyTransactions: true
 
 ApplicationConfiguration:
   DBConfiguration:

config/protocol.privnet.docker.two.yml

@@ -12,6 +12,8 @@ ProtocolConfiguration:
     IssueTransaction: 500
     PublishTransaction: 500
     RegisterTransaction: 10000
+  VerifyBlocks: true
+  VerifyTransactions: true
 
 ApplicationConfiguration:
   DBConfiguration:

config/protocol.privnet.yml

@@ -18,6 +18,8 @@ ProtocolConfiguration:
     IssueTransaction: 500
     PublishTransaction: 500
     RegisterTransaction: 10000
+  VerifyBlocks: true
+  VerifyTransactions: true
 
 ApplicationConfiguration:
   DBConfiguration:

config/protocol.testnet.yml

@@ -27,6 +27,8 @@ ProtocolConfiguration:
     IssueTransaction: 5
     PublishTransaction: 5
     RegisterTransaction: 100
+  VerifyBlocks: true
+  VerifyTransactions: false
 
 ApplicationConfiguration:
   DBConfiguration:

config/protocol.unit_testnet.yml

@@ -17,6 +17,8 @@ ProtocolConfiguration:
     IssueTransaction: 500
     PublishTransaction: 500
     RegisterTransaction: 10000
+  VerifyBlocks: true
+  VerifyTransactions: true
 
 ApplicationConfiguration:
   DBConfiguration:

pkg/core/asset_state.go

@@ -27,6 +27,17 @@ func (a Assets) commit(b storage.Batch) error {
 	return nil
 }
 
+// putAssetStateIntoStore puts given asset state into the given store.
+func putAssetStateIntoStore(s storage.Store, as *AssetState) error {
+	buf := io.NewBufBinWriter()
+	as.EncodeBinary(buf.BinWriter)
+	if buf.Err != nil {
+		return buf.Err
+	}
+	key := storage.AppendPrefix(storage.STAsset, as.ID.Bytes())
+	return s.Put(key, buf.Bytes())
+}
+
 // AssetState represents the state of an NEO registered Asset.
 type AssetState struct {
 	ID         util.Uint256

pkg/core/asset_state_test.go

@@ -3,6 +3,7 @@ package core
 import (
 	"testing"
 
+	"github.com/CityOfZion/neo-go/pkg/core/storage"
 	"github.com/CityOfZion/neo-go/pkg/core/transaction"
 	"github.com/CityOfZion/neo-go/pkg/crypto/keys"
 	"github.com/CityOfZion/neo-go/pkg/io"
@@ -35,3 +36,25 @@ func TestEncodeDecodeAssetState(t *testing.T) {
 	assert.Nil(t, r.Err)
 	assert.Equal(t, asset, assetDecode)
 }
+
+func TestPutGetAssetState(t *testing.T) {
+	s := storage.NewMemoryStore()
+	asset := &AssetState{
+		ID:         randomUint256(),
+		AssetType:  transaction.Token,
+		Name:       "super cool token",
+		Amount:     util.Fixed8(1000000),
+		Available:  util.Fixed8(100),
+		Precision:  8,
+		FeeMode:    feeMode,
+		Owner:      &keys.PublicKey{},
+		Admin:      randomUint160(),
+		Issuer:     randomUint160(),
+		Expiration: 10,
+		IsFrozen:   false,
+	}
+	assert.NoError(t, putAssetStateIntoStore(s, asset))
+	asRead := getAssetStateFromStore(s, asset.ID)
+	assert.NotNil(t, asRead)
+	assert.Equal(t, asset, asRead)
+}

pkg/core/block.go

@@ -1,12 +1,14 @@
 package core
 
 import (
+	"errors"
+	"fmt"
+
 	"github.com/CityOfZion/neo-go/pkg/core/transaction"
 	"github.com/CityOfZion/neo-go/pkg/crypto"
 	"github.com/CityOfZion/neo-go/pkg/io"
 	"github.com/CityOfZion/neo-go/pkg/util"
 	"github.com/Workiva/go-datastructures/queue"
-	log "github.com/sirupsen/logrus"
 )
 
 // Block represents one block in the chain.
@@ -28,14 +30,18 @@ func (b *Block) Header() *Header {
 	}
 }
 
-// rebuildMerkleRoot rebuild the merkleroot of the block.
-func (b *Block) rebuildMerkleRoot() error {
-	hashes := make([]util.Uint256, len(b.Transactions))
-	for i, tx := range b.Transactions {
+func merkleTreeFromTransactions(txes []*transaction.Transaction) (*crypto.MerkleTree, error) {
+	hashes := make([]util.Uint256, len(txes))
+	for i, tx := range txes {
 		hashes[i] = tx.Hash()
 	}
 
-	merkle, err := crypto.NewMerkleTree(hashes)
+	return crypto.NewMerkleTree(hashes)
+}
+
+// rebuildMerkleRoot rebuild the merkleroot of the block.
+func (b *Block) rebuildMerkleRoot() error {
+	merkle, err := merkleTreeFromTransactions(b.Transactions)
 	if err != nil {
 		return err
 	}
@@ -45,26 +51,29 @@ func (b *Block) rebuildMerkleRoot() error {
 }
 
 // Verify the integrity of the block.
-func (b *Block) Verify(full bool) bool {
+func (b *Block) Verify() error {
 	// There has to be some transaction inside.
 	if len(b.Transactions) == 0 {
-		return false
+		return errors.New("no transactions")
 	}
 	// The first TX has to be a miner transaction.
 	if b.Transactions[0].Type != transaction.MinerType {
-		return false
+		return fmt.Errorf("the first transaction is %s", b.Transactions[0].Type)
 	}
 	// If the first TX is a minerTX then all others cant.
 	for _, tx := range b.Transactions[1:] {
 		if tx.Type == transaction.MinerType {
-			return false
+			return fmt.Errorf("miner transaction %s is not the first one", tx.Hash().ReverseString())
 		}
 	}
-	// TODO: When full is true, do a full verification.
-	if full {
-		log.Warn("full verification of blocks is not yet implemented")
+	merkle, err := merkleTreeFromTransactions(b.Transactions)
+	if err != nil {
+		return err
 	}
-	return true
+	if !b.MerkleRoot.Equals(merkle.Root()) {
+		return errors.New("MerkleRoot mismatch")
+	}
+	return nil
 }
 
 // NewBlockFromTrimmedBytes returns a new block from trimmed data.

pkg/core/block_base.go

@@ -40,8 +40,11 @@ type BlockBase struct {
 	// Script used to validate the block
 	Script *transaction.Witness `json:"script"`
 
-	// hash of this block, created when binary encoded.
+	// Hash of this block, created when binary encoded (double SHA256).
 	hash util.Uint256
+
+	// Hash of the block used to verify it (single SHA256).
+	verificationHash util.Uint256
 }
 
 // Verify verifies the integrity of the BlockBase.
@@ -58,6 +61,16 @@ func (b *BlockBase) Hash() util.Uint256 {
 	return b.hash
 }
 
+// VerificationHash returns the hash of the block used to verify it.
+func (b *BlockBase) VerificationHash() util.Uint256 {
+	if b.verificationHash.Equals(util.Uint256{}) {
+		if b.createHash() != nil {
+			panic("failed to compute hash!")
+		}
+	}
+	return b.verificationHash
+}
+
 // DecodeBinary implements Serializable interface.
 func (b *BlockBase) DecodeBinary(br *io.BinReader) {
 	b.decodeHashableFields(br)
@@ -80,6 +93,16 @@ func (b *BlockBase) EncodeBinary(bw *io.BinWriter) {
 	b.Script.EncodeBinary(bw)
 }
 
+// getHashableData returns serialized hashable data of the block.
+func (b *BlockBase) getHashableData() ([]byte, error) {
+	buf := io.NewBufBinWriter()
+	b.encodeHashableFields(buf.BinWriter)
+	if buf.Err != nil {
+		return nil, buf.Err
+	}
+	return buf.Bytes(), nil
+}
+
 // createHash creates the hash of the block.
 // When calculating the hash value of the block, instead of calculating the entire block,
 // only first seven fields in the block head will be calculated, which are
@@ -87,12 +110,12 @@ func (b *BlockBase) EncodeBinary(bw *io.BinWriter) {
 // Since MerkleRoot already contains the hash value of all transactions,
 // the modification of transaction will influence the hash value of the block.
 func (b *BlockBase) createHash() error {
-	buf := io.NewBufBinWriter()
-	b.encodeHashableFields(buf.BinWriter)
-	if buf.Err != nil {
-		return buf.Err
+	bb, err := b.getHashableData()
+	if err != nil {
+		return err
 	}
-	b.hash = hash.DoubleSha256(buf.Bytes())
+	b.hash = hash.DoubleSha256(bb)
+	b.verificationHash = hash.Sha256(bb)
 
 	return nil
 }

pkg/core/block_test.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/CityOfZion/neo-go/pkg/core/transaction"
 	"github.com/CityOfZion/neo-go/pkg/crypto"
+	"github.com/CityOfZion/neo-go/pkg/crypto/hash"
 	"github.com/CityOfZion/neo-go/pkg/io"
 	"github.com/stretchr/testify/assert"
 )
@@ -76,30 +77,59 @@ func TestTrimmedBlock(t *testing.T) {
 	}
 }
 
+func newDumbBlock() *Block {
+	return &Block{
+		BlockBase: BlockBase{
+			Version:       0,
+			PrevHash:      hash.Sha256([]byte("a")),
+			MerkleRoot:    hash.Sha256([]byte("b")),
+			Timestamp:     uint32(100500),
+			Index:         1,
+			ConsensusData: 1111,
+			NextConsensus: hash.Hash160([]byte("a")),
+			Script: &transaction.Witness{
+				VerificationScript: []byte{0x51}, // PUSH1
+				InvocationScript:   []byte{0x61}, // NOP
+			},
+		},
+		Transactions: []*transaction.Transaction{
+			{Type: transaction.MinerType},
+			{Type: transaction.IssueType},
+		},
+	}
+}
+
 func TestHashBlockEqualsHashHeader(t *testing.T) {
-	block := newBlock(0)
+	block := newDumbBlock()
+
 	assert.Equal(t, block.Hash(), block.Header().Hash())
 }
 
 func TestBlockVerify(t *testing.T) {
-	block := newBlock(
-		0,
-		newTX(transaction.MinerType),
-		newTX(transaction.IssueType),
-	)
-	assert.True(t, block.Verify(false))
+	block := newDumbBlock()
+	assert.NotNil(t, block.Verify())
+	assert.Nil(t, block.rebuildMerkleRoot())
+	assert.Nil(t, block.Verify())
 
 	block.Transactions = []*transaction.Transaction{
 		{Type: transaction.IssueType},
 		{Type: transaction.MinerType},
 	}
-	assert.False(t, block.Verify(false))
+	assert.NoError(t, block.rebuildMerkleRoot())
+	assert.NotNil(t, block.Verify())
 
 	block.Transactions = []*transaction.Transaction{
 		{Type: transaction.MinerType},
 		{Type: transaction.MinerType},
 	}
-	assert.False(t, block.Verify(false))
+	assert.NoError(t, block.rebuildMerkleRoot())
+	assert.NotNil(t, block.Verify())
+	block.Transactions = []*transaction.Transaction{
+		{Type: transaction.MinerType},
+		{Type: transaction.IssueType},
+		{Type: transaction.IssueType},
+	}
+	assert.NotNil(t, block.Verify())
 }
 
 func TestBinBlockDecodeEncode(t *testing.T) {

pkg/core/blockchain.go

@@ -13,6 +13,7 @@ import (
 	"github.com/CityOfZion/neo-go/pkg/core/storage"
 	"github.com/CityOfZion/neo-go/pkg/core/transaction"
 	"github.com/CityOfZion/neo-go/pkg/io"
+	"github.com/CityOfZion/neo-go/pkg/smartcontract"
 	"github.com/CityOfZion/neo-go/pkg/util"
 	"github.com/CityOfZion/neo-go/pkg/vm"
 	"github.com/pkg/errors"
@@ -67,9 +68,6 @@ type Blockchain struct {
 	headersOp     chan headersOpFunc
 	headersOpDone chan struct{}
 
-	// Whether we will verify received blocks.
-	verifyBlocks bool
-
 	memPool MemPool
 }
 
@@ -84,7 +82,6 @@ func NewBlockchain(s storage.Store, cfg config.ProtocolConfiguration) (*Blockcha
 		memStore:      storage.NewMemoryStore(),
 		headersOp:     make(chan headersOpFunc),
 		headersOpDone: make(chan struct{}),
-		verifyBlocks:  false,
 		memPool:       NewMemPool(50000),
 	}
 
@@ -208,17 +205,23 @@ func (bc *Blockchain) AddBlock(block *Block) error {
 	if expectedHeight != block.Index {
 		return fmt.Errorf("expected block %d, but passed block %d", expectedHeight, block.Index)
 	}
-	if bc.verifyBlocks {
-		if !block.Verify(false) {
-			return fmt.Errorf("block %s is invalid", block.Hash())
+	if bc.config.VerifyBlocks {
+		err := block.Verify()
+		if err == nil {
+			err = bc.VerifyBlock(block)
 		}
+		if err != nil {
+			return fmt.Errorf("block %s is invalid: %s", block.Hash().ReverseString(), err)
+		}
+		if bc.config.VerifyTransactions {
 			for _, tx := range block.Transactions {
-			err := bc.Verify(tx)
+				err := bc.VerifyTx(tx, block)
 				if err != nil {
 					return fmt.Errorf("transaction %s failed to verify: %s", tx.Hash().ReverseString(), err)
 				}
 			}
 		}
+	}
 	headerLen := bc.headerListLen()
 	if int(block.Index) == headerLen {
 		err := bc.AddHeaders(block.Header())
@@ -238,6 +241,7 @@ func (bc *Blockchain) AddHeaders(headers ...*Header) (err error) {
 	)
 
 	bc.headersOp <- func(headerList *HeaderHashList) {
+		oldlen := headerList.Len()
 		for _, h := range headers {
 			if int(h.Index-1) >= headerList.Len() {
 				err = fmt.Errorf(
@@ -258,7 +262,7 @@ func (bc *Blockchain) AddHeaders(headers ...*Header) (err error) {
 			}
 		}
 
-		if batch.Len() > 0 {
+		if oldlen != headerList.Len() {
 			if err = bc.memStore.PutBatch(batch); err != nil {
 				return
 			}
@@ -389,11 +393,15 @@ func (bc *Blockchain) storeBlock(block *Block) error {
 		case *transaction.EnrollmentTX:
 		case *transaction.StateTX:
 		case *transaction.PublishTX:
+			var properties smartcontract.PropertyState
+			if t.NeedStorage {
+				properties |= smartcontract.HasStorage
+			}
 			contract := &ContractState{
 				Script:      t.Script,
 				ParamList:   t.ParamList,
 				ReturnType:  t.ReturnType,
-				HasStorage:  t.NeedStorage,
+				Properties:  properties,
 				Name:        t.Name,
 				CodeVersion: t.CodeVersion,
 				Author:      t.Author,
@@ -403,6 +411,32 @@ func (bc *Blockchain) storeBlock(block *Block) error {
 			contracts[contract.ScriptHash()] = contract
 
 		case *transaction.InvocationTX:
+			vm := vm.New(vm.ModeMute)
+			vm.SetCheckedHash(tx.VerificationHash().Bytes())
+			vm.SetScriptGetter(func(hash util.Uint160) []byte {
+				cs := bc.GetContractState(hash)
+				if cs == nil {
+					return nil
+				}
+
+				return cs.Script
+			})
+			systemInterop := newInteropContext(0x10, bc, block, tx)
+			vm.RegisterInteropFuncs(systemInterop.getSystemInteropMap())
+			vm.RegisterInteropFuncs(systemInterop.getNeoInteropMap())
+			vm.LoadScript(t.Script)
+			vm.Run()
+			if !vm.HasFailed() {
+				_, err := systemInterop.mem.Persist(bc.memStore)
+				if err != nil {
+					return errors.Wrap(err, "failed to persist invocation results")
+				}
+			} else {
+				log.WithFields(log.Fields{
+					"tx":    tx.Hash().ReverseString(),
+					"block": block.Index,
+				}).Warn("contract invocation failed")
+			}
 		}
 	}
 
@@ -455,7 +489,7 @@ func (bc *Blockchain) persist(ctx context.Context) error {
 			"persistedKeys":   persisted,
 			"headerHeight":    bc.HeaderHeight(),
 			"blockHeight":     bc.BlockHeight(),
-			"persistedHeight": bc.persistedHeight,
+			"persistedHeight": atomic.LoadUint32(&bc.persistedHeight),
 			"took":            time.Since(start),
 		}).Info("blockchain persist completed")
 	}
@@ -505,6 +539,43 @@ func getTransactionFromStore(s storage.Store, hash util.Uint256) (*transaction.T
 	return tx, height, nil
 }
 
+// GetStorageItem returns an item from storage.
+func (bc *Blockchain) GetStorageItem(scripthash util.Uint160, key []byte) *StorageItem {
+	sItem := getStorageItemFromStore(bc.memStore, scripthash, key)
+	if sItem == nil {
+		sItem = getStorageItemFromStore(bc.Store, scripthash, key)
+	}
+	return sItem
+}
+
+// GetStorageItems returns all storage items for a given scripthash.
+func (bc *Blockchain) GetStorageItems(hash util.Uint160) (map[string]*StorageItem, error) {
+	var siMap = make(map[string]*StorageItem)
+	var err error
+
+	saveToMap := func(k, v []byte) {
+		if err != nil {
+			return
+		}
+		r := io.NewBinReaderFromBuf(v)
+		si := &StorageItem{}
+		si.DecodeBinary(r)
+		if r.Err != nil {
+			err = r.Err
+			return
+		}
+
+		// Cut prefix and hash.
+		siMap[string(k[21:])] = si
+	}
+	bc.memStore.Seek(storage.AppendPrefix(storage.STStorage, hash.BytesReverse()), saveToMap)
+	bc.Store.Seek(storage.AppendPrefix(storage.STStorage, hash.BytesReverse()), saveToMap)
+	if err != nil {
+		return nil, err
+	}
+	return siMap, nil
+}
+
 // GetBlock returns a Block by the given hash.
 func (bc *Blockchain) GetBlock(hash util.Uint256) (*Block, error) {
 	block, err := getBlockFromStore(bc.memStore, hash)
@@ -517,6 +588,13 @@ func (bc *Blockchain) GetBlock(hash util.Uint256) (*Block, error) {
 	if len(block.Transactions) == 0 {
 		return nil, fmt.Errorf("only header is available")
 	}
+	for _, tx := range block.Transactions {
+		stx, _, err := bc.GetTransaction(tx.Hash())
+		if err != nil {
+			return nil, err
+		}
+		*tx = *stx
+	}
 	return block, nil
 }
 
@@ -689,6 +767,15 @@ func (bc *Blockchain) GetAccountState(scriptHash util.Uint160) *AccountState {
 	return as
 }
 
+// GetUnspentCoinState returns unspent coin state for given tx hash.
+func (bc *Blockchain) GetUnspentCoinState(hash util.Uint256) *UnspentCoinState {
+	ucs, err := getUnspentCoinStateFromStore(bc.memStore, hash)
+	if err != nil {
+		ucs, _ = getUnspentCoinStateFromStore(bc.Store, hash)
+	}
+	return ucs
+}
+
 // GetConfig returns the config stored in the blockchain
 func (bc *Blockchain) GetConfig() config.ProtocolConfiguration {
 	return bc.config
@@ -756,9 +843,26 @@ func (bc *Blockchain) GetMemPool() MemPool {
 	return bc.memPool
 }
 
-// Verify verifies whether a transaction is bonafide or not.
+// VerifyBlock verifies block against its current state.
+func (bc *Blockchain) VerifyBlock(block *Block) error {
+	prevHeader, err := bc.GetHeader(block.PrevHash)
+	if err != nil {
+		return errors.Wrap(err, "unable to get previous header")
+	}
+	if prevHeader.Index+1 != block.Index {
+		return errors.New("previous header index doesn't match")
+	}
+	if prevHeader.Timestamp >= block.Timestamp {
+		return errors.New("block is not newer than the previous one")
+	}
+	return bc.verifyBlockWitnesses(block, prevHeader)
+}
+
+// VerifyTx verifies whether a transaction is bonafide or not. Block parameter
+// is used for easy interop access and can be omitted for transactions that are
+// not yet added into any block.
 // Golang implementation of Verify method in C# (https://github.com/neo-project/neo/blob/master/neo/Network/P2P/Payloads/Transaction.cs#L270).
-func (bc *Blockchain) Verify(t *transaction.Transaction) error {
+func (bc *Blockchain) VerifyTx(t *transaction.Transaction, block *Block) error {
 	if io.GetVarSize(t) > transaction.MaxTransactionSize {
 		return errors.Errorf("invalid transaction size = %d. It shoud be less then MaxTransactionSize = %d", io.GetVarSize(t), transaction.MaxTransactionSize)
 	}
@@ -771,11 +875,11 @@ func (bc *Blockchain) Verify(t *transaction.Transaction) error {
 	if IsDoubleSpend(bc.Store, t) {
 		return errors.New("invalid transaction caused by double spending")
 	}
-	if ok := bc.verifyOutputs(t); !ok {
-		return errors.New("invalid transaction's outputs")
+	if err := bc.verifyOutputs(t); err != nil {
+		return errors.Wrap(err, "wrong outputs")
 	}
-	if ok := bc.verifyResults(t); !ok {
-		return errors.New("invalid transaction's results")
+	if err := bc.verifyResults(t); err != nil {
+		return err
 	}
 
 	for _, a := range t.Attributes {
@@ -784,7 +888,7 @@ func (bc *Blockchain) Verify(t *transaction.Transaction) error {
 		}
 	}
 
-	return bc.VerifyWitnesses(t)
+	return bc.verifyTxWitnesses(t, block)
 }
 
 func (bc *Blockchain) verifyInputs(t *transaction.Transaction) bool {
@@ -799,31 +903,31 @@ func (bc *Blockchain) verifyInputs(t *transaction.Transaction) bool {
 	return true
 }
 
-func (bc *Blockchain) verifyOutputs(t *transaction.Transaction) bool {
+func (bc *Blockchain) verifyOutputs(t *transaction.Transaction) error {
 	for assetID, outputs := range t.GroupOutputByAssetID() {
 		assetState := bc.GetAssetState(assetID)
 		if assetState == nil {
-			return false
+			return fmt.Errorf("no asset state for %s", assetID.ReverseString())
 		}
 
 		if assetState.Expiration < bc.blockHeight+1 && assetState.AssetType != transaction.GoverningToken && assetState.AssetType != transaction.UtilityToken {
-			return false
+			return fmt.Errorf("asset %s expired", assetID.ReverseString())
 		}
 
 		for _, out := range outputs {
 			if int64(out.Amount)%int64(math.Pow10(8-int(assetState.Precision))) != 0 {
-				return false
+				return fmt.Errorf("output is not compliant with %s asset precision", assetID.ReverseString())
 			}
 		}
 	}
 
-	return true
+	return nil
 }
 
-func (bc *Blockchain) verifyResults(t *transaction.Transaction) bool {
-	results := bc.GetTransationResults(t)
+func (bc *Blockchain) verifyResults(t *transaction.Transaction) error {
+	results := bc.GetTransactionResults(t)
 	if results == nil {
-		return false
+		return errors.New("tx has no results")
 	}
 	var resultsDestroy []*transaction.Result
 	var resultsIssue []*transaction.Result
@@ -837,43 +941,49 @@ func (bc *Blockchain) verifyResults(t *transaction.Transaction) bool {
 		}
 	}
 	if len(resultsDestroy) > 1 {
-		return false
+		return errors.New("tx has more than 1 destroy output")
 	}
 	if len(resultsDestroy) == 1 && resultsDestroy[0].AssetID != utilityTokenTX().Hash() {
-		return false
+		return errors.New("tx destroys non-utility token")
+	}
+	sysfee := bc.SystemFee(t)
+	if sysfee.GreaterThan(util.Fixed8(0)) {
+		if len(resultsDestroy) == 0 {
+			return fmt.Errorf("system requires to pay %s fee, but tx pays nothing", sysfee.String())
+		}
+		if resultsDestroy[0].Amount.LessThan(sysfee) {
+			return fmt.Errorf("system requires to pay %s fee, but tx pays %s only", sysfee.String(), resultsDestroy[0].Amount.String())
 		}
-	if bc.SystemFee(t).GreaterThan(util.Fixed8(0)) && (len(resultsDestroy) == 0 || resultsDestroy[0].Amount.LessThan(bc.SystemFee(t))) {
-		return false
 	}
 
 	switch t.Type {
 	case transaction.MinerType, transaction.ClaimType:
 		for _, r := range resultsIssue {
 			if r.AssetID != utilityTokenTX().Hash() {
-				return false
+				return errors.New("miner or claim tx issues non-utility tokens")
 			}
 		}
 		break
 	case transaction.IssueType:
 		for _, r := range resultsIssue {
 			if r.AssetID == utilityTokenTX().Hash() {
-				return false
+				return errors.New("issue tx issues utility tokens")
 			}
 		}
 		break
 	default:
 		if len(resultsIssue) > 0 {
-			return false
+			return errors.New("non issue/miner/claim tx issues tokens")
 		}
 		break
 	}
 
-	return true
+	return nil
 }
 
-// GetTransationResults returns the transaction results aggregate by assetID.
+// GetTransactionResults returns the transaction results aggregate by assetID.
 // Golang of GetTransationResults method in C# (https://github.com/neo-project/neo/blob/master/neo/Network/P2P/Payloads/Transaction.cs#L207)
-func (bc *Blockchain) GetTransationResults(t *transaction.Transaction) []*transaction.Result {
+func (bc *Blockchain) GetTransactionResults(t *transaction.Transaction) []*transaction.Result {
 	var tempResults []*transaction.Result
 	var results []*transaction.Result
 	tempGroupResult := make(map[util.Uint256]util.Fixed8)
@@ -918,7 +1028,8 @@ func (bc *Blockchain) GetTransationResults(t *transaction.Transaction) []*transa
 // GetScriptHashesForVerifyingClaim returns all ScriptHashes of Claim transaction
 // which has a different implementation from generic GetScriptHashesForVerifying.
 func (bc *Blockchain) GetScriptHashesForVerifyingClaim(t *transaction.Transaction) ([]util.Uint160, error) {
-	hashes := make([]util.Uint160, 0)
+	// Avoiding duplicates.
+	hashmap := make(map[util.Uint160]bool)
 
 	claim := t.Data.(*transaction.ClaimTX)
 	clGroups := make(map[util.Uint256][]*transaction.Input)
@@ -934,10 +1045,14 @@ func (bc *Blockchain) GetScriptHashesForVerifyingClaim(t *transaction.Transactio
 			if len(refTx.Outputs) <= int(input.PrevIndex) {
 				return nil, fmt.Errorf("wrong PrevIndex reference")
 			}
-			hashes = append(hashes, refTx.Outputs[input.PrevIndex].ScriptHash)
+			hashmap[refTx.Outputs[input.PrevIndex].ScriptHash] = true
 		}
 	}
-	if len(hashes) > 0 {
+	if len(hashmap) > 0 {
+		hashes := make([]util.Uint160, 0, len(hashmap))
+		for k := range hashmap {
+			hashes = append(hashes, k)
+		}
 		return hashes, nil
 	}
 	return nil, fmt.Errorf("no hashes found")
@@ -997,41 +1112,25 @@ func (bc *Blockchain) GetScriptHashesForVerifying(t *transaction.Transaction) ([
 
 }
 
-// VerifyWitnesses verify the scripts (witnesses) that come with a given
-// transaction. It can reorder them by ScriptHash, because that's required to
-// match a slice of script hashes from the Blockchain.
-// Golang implementation of VerifyWitnesses method in C# (https://github.com/neo-project/neo/blob/master/neo/SmartContract/Helper.cs#L87).
-// Unfortunately the IVerifiable interface could not be implemented because we can't move the References method in blockchain.go to the transaction.go file
-func (bc *Blockchain) VerifyWitnesses(t *transaction.Transaction) error {
-	hashes, err := bc.GetScriptHashesForVerifying(t)
-	if err != nil {
-		return err
-	}
-
-	witnesses := t.Scripts
-	if len(hashes) != len(witnesses) {
-		return errors.Errorf("expected len(hashes) == len(witnesses). got: %d != %d", len(hashes), len(witnesses))
-	}
-	sort.Slice(hashes, func(i, j int) bool { return hashes[i].Less(hashes[j]) })
-	sort.Slice(witnesses, func(i, j int) bool { return witnesses[i].ScriptHash().Less(witnesses[j].ScriptHash()) })
-	for i := 0; i < len(hashes); i++ {
-		verification := witnesses[i].VerificationScript
+// verifyHashAgainstScript verifies given hash against the given witness.
+func (bc *Blockchain) verifyHashAgainstScript(hash util.Uint160, witness *transaction.Witness, checkedHash util.Uint256, interopCtx *interopContext) error {
+	verification := witness.VerificationScript
 
 	if len(verification) == 0 {
 		bb := new(bytes.Buffer)
-			err = vm.EmitAppCall(bb, hashes[i], false)
+		err := vm.EmitAppCall(bb, hash, false)
 		if err != nil {
 			return err
 		}
 		verification = bb.Bytes()
 	} else {
-			if h := witnesses[i].ScriptHash(); hashes[i] != h {
-				return errors.Errorf("hash mismatch for script #%d", i)
+		if h := witness.ScriptHash(); hash != h {
+			return errors.New("witness hash mismatch")
 		}
 	}
 
 	vm := vm.New(vm.ModeMute)
-		vm.SetCheckedHash(t.VerificationHash().Bytes())
+	vm.SetCheckedHash(checkedHash.Bytes())
 	vm.SetScriptGetter(func(hash util.Uint160) []byte {
 		cs := bc.GetContractState(hash)
 		if cs == nil {
@@ -1039,8 +1138,10 @@ func (bc *Blockchain) VerifyWitnesses(t *transaction.Transaction) error {
 		}
 		return cs.Script
 	})
+	vm.RegisterInteropFuncs(interopCtx.getSystemInteropMap())
+	vm.RegisterInteropFuncs(interopCtx.getNeoInteropMap())
 	vm.LoadScript(verification)
-		vm.LoadScript(witnesses[i].InvocationScript)
+	vm.LoadScript(witness.InvocationScript)
 	vm.Run()
 	if vm.HasFailed() {
 		return errors.Errorf("vm failed to execute the script")
@@ -1057,11 +1158,52 @@ func (bc *Blockchain) VerifyWitnesses(t *transaction.Transaction) error {
 	} else {
 		return errors.Errorf("no result returned from the script")
 	}
+	return nil
+}
+
+// verifyTxWitnesses verify the scripts (witnesses) that come with a given
+// transaction. It can reorder them by ScriptHash, because that's required to
+// match a slice of script hashes from the Blockchain. Block parameter
+// is used for easy interop access and can be omitted for transactions that are
+// not yet added into any block.
+// Golang implementation of VerifyWitnesses method in C# (https://github.com/neo-project/neo/blob/master/neo/SmartContract/Helper.cs#L87).
+// Unfortunately the IVerifiable interface could not be implemented because we can't move the References method in blockchain.go to the transaction.go file
+func (bc *Blockchain) verifyTxWitnesses(t *transaction.Transaction, block *Block) error {
+	hashes, err := bc.GetScriptHashesForVerifying(t)
+	if err != nil {
+		return err
+	}
+
+	witnesses := t.Scripts
+	if len(hashes) != len(witnesses) {
+		return errors.Errorf("expected len(hashes) == len(witnesses). got: %d != %d", len(hashes), len(witnesses))
+	}
+	sort.Slice(hashes, func(i, j int) bool { return hashes[i].Less(hashes[j]) })
+	sort.Slice(witnesses, func(i, j int) bool { return witnesses[i].ScriptHash().Less(witnesses[j].ScriptHash()) })
+	interopCtx := newInteropContext(0, bc, block, t)
+	for i := 0; i < len(hashes); i++ {
+		err := bc.verifyHashAgainstScript(hashes[i], witnesses[i], t.VerificationHash(), interopCtx)
+		if err != nil {
+			numStr := fmt.Sprintf("witness #%d", i)
+			return errors.Wrap(err, numStr)
+		}
 	}
 
 	return nil
 }
 
+// verifyBlockWitnesses is a block-specific implementation of VerifyWitnesses logic.
+func (bc *Blockchain) verifyBlockWitnesses(block *Block, prevHeader *Header) error {
+	var hash util.Uint160
+	if prevHeader == nil && block.PrevHash.Equals(util.Uint256{}) {
+		hash = block.Script.ScriptHash()
+	} else {
+		hash = prevHeader.NextConsensus
+	}
+	interopCtx := newInteropContext(0, bc, nil, nil)
+	return bc.verifyHashAgainstScript(hash, block.Script, block.VerificationHash(), interopCtx)
+}
+
 func hashAndIndexToBytes(h util.Uint256, index uint32) []byte {
 	buf := io.NewBufBinWriter()
 	buf.WriteLE(h.BytesReverse())

pkg/core/blockchain_test.go

@@ -4,9 +4,7 @@ import (
 	"context"
 	"testing"
 
-	"github.com/CityOfZion/neo-go/config"
 	"github.com/CityOfZion/neo-go/pkg/core/storage"
-	"github.com/CityOfZion/neo-go/pkg/core/transaction"
 	"github.com/CityOfZion/neo-go/pkg/io"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
@@ -39,9 +37,9 @@ func TestAddHeaders(t *testing.T) {
 func TestAddBlock(t *testing.T) {
 	bc := newTestChain(t)
 	blocks := []*Block{
-		newBlock(1, newTX(transaction.MinerType)),
-		newBlock(2, newTX(transaction.MinerType)),
-		newBlock(3, newTX(transaction.MinerType)),
+		newBlock(1, newMinerTX()),
+		newBlock(2, newMinerTX()),
+		newBlock(3, newMinerTX()),
 	}
 
 	for i := 0; i < len(blocks); i++ {
@@ -70,7 +68,7 @@ func TestAddBlock(t *testing.T) {
 
 func TestGetHeader(t *testing.T) {
 	bc := newTestChain(t)
-	block := newBlock(1, newTX(transaction.MinerType))
+	block := newBlock(1, newMinerTX())
 	err := bc.AddBlock(block)
 	assert.Nil(t, err)
 
@@ -103,7 +101,7 @@ func TestGetBlock(t *testing.T) {
 		for i := 0; i < len(blocks); i++ {
 			block, err := bc.GetBlock(blocks[i].Hash())
 			if err != nil {
-				t.Fatal(err)
+				t.Fatalf("can't get block %d: %s, attempt %d", i, err, j)
 			}
 			assert.Equal(t, blocks[i].Index, block.Index)
 			assert.Equal(t, blocks[i].Hash(), block.Hash())
@@ -138,8 +136,9 @@ func TestGetTransaction(t *testing.T) {
 	block := getDecodedBlock(t, 2)
 	bc := newTestChain(t)
 
-	assert.Nil(t, bc.AddBlock(b1))
-	assert.Nil(t, bc.AddBlock(block))
+	// These are from some kind of different chain, so can't be added via AddBlock().
+	assert.Nil(t, bc.storeBlock(b1))
+	assert.Nil(t, bc.storeBlock(block))
 
 	// Test unpersisted and persisted access
 	for j := 0; j < 2; j++ {
@@ -155,16 +154,3 @@ func TestGetTransaction(t *testing.T) {
 		assert.NoError(t, bc.persist(context.Background()))
 	}
 }
-
-func newTestChain(t *testing.T) *Blockchain {
-	cfg, err := config.Load("../../config", config.ModeUnitTestNet)
-	if err != nil {
-		t.Fatal(err)
-	}
-	chain, err := NewBlockchain(storage.NewMemoryStore(), cfg.ProtocolConfiguration)
-	if err != nil {
-		t.Fatal(err)
-	}
-	go chain.Run(context.Background())
-	return chain
-}

pkg/core/blockchainer.go

@@ -15,6 +15,7 @@ type Blockchainer interface {
 	BlockHeight() uint32
 	HeaderHeight() uint32
 	GetBlock(hash util.Uint256) (*Block, error)
+	GetContractState(hash util.Uint160) *ContractState
 	GetHeaderHash(int) util.Uint256
 	GetHeader(hash util.Uint256) (*Header, error)
 	CurrentHeaderHash() util.Uint256
@@ -23,9 +24,13 @@ type Blockchainer interface {
 	HasTransaction(util.Uint256) bool
 	GetAssetState(util.Uint256) *AssetState
 	GetAccountState(util.Uint160) *AccountState
+	GetScriptHashesForVerifying(*transaction.Transaction) ([]util.Uint160, error)
+	GetStorageItem(scripthash util.Uint160, key []byte) *StorageItem
+	GetStorageItems(hash util.Uint160) (map[string]*StorageItem, error)
 	GetTransaction(util.Uint256) (*transaction.Transaction, uint32, error)
+	GetUnspentCoinState(util.Uint256) *UnspentCoinState
 	References(t *transaction.Transaction) map[transaction.Input]*transaction.Output
 	Feer // fee interface
-	Verify(t *transaction.Transaction) error
+	VerifyTx(*transaction.Transaction, *Block) error
 	GetMemPool() MemPool
 }

pkg/core/contract_state.go

@@ -16,14 +16,12 @@ type ContractState struct {
 	Script      []byte
 	ParamList   []smartcontract.ParamType
 	ReturnType  smartcontract.ParamType
-	Properties       []byte
+	Properties  smartcontract.PropertyState
 	Name        string
 	CodeVersion string
 	Author      string
 	Email       string
 	Description string
-	HasStorage       bool
-	HasDynamicInvoke bool
 
 	scriptHash util.Uint160
 }
@@ -44,52 +42,80 @@ func (a Contracts) commit(b storage.Batch) error {
 }
 
 // DecodeBinary implements Serializable interface.
-func (a *ContractState) DecodeBinary(br *io.BinReader) {
-	a.Script = br.ReadBytes()
+func (cs *ContractState) DecodeBinary(br *io.BinReader) {
+	cs.Script = br.ReadBytes()
 	paramBytes := br.ReadBytes()
-	a.ParamList = make([]smartcontract.ParamType, len(paramBytes))
+	cs.ParamList = make([]smartcontract.ParamType, len(paramBytes))
 	for k := range paramBytes {
-		a.ParamList[k] = smartcontract.ParamType(paramBytes[k])
+		cs.ParamList[k] = smartcontract.ParamType(paramBytes[k])
 	}
-	br.ReadLE(&a.ReturnType)
-	a.Properties = br.ReadBytes()
-	a.Name = br.ReadString()
-	a.CodeVersion = br.ReadString()
-	a.Author = br.ReadString()
-	a.Email = br.ReadString()
-	a.Description = br.ReadString()
-	br.ReadLE(&a.HasStorage)
-	br.ReadLE(&a.HasDynamicInvoke)
-	a.createHash()
+	br.ReadLE(&cs.ReturnType)
+	br.ReadLE(&cs.Properties)
+	cs.Name = br.ReadString()
+	cs.CodeVersion = br.ReadString()
+	cs.Author = br.ReadString()
+	cs.Email = br.ReadString()
+	cs.Description = br.ReadString()
+	cs.createHash()
 }
 
 // EncodeBinary implements Serializable interface.
-func (a *ContractState) EncodeBinary(bw *io.BinWriter) {
-	bw.WriteBytes(a.Script)
-	bw.WriteVarUint(uint64(len(a.ParamList)))
-	for k := range a.ParamList {
-		bw.WriteLE(a.ParamList[k])
+func (cs *ContractState) EncodeBinary(bw *io.BinWriter) {
+	bw.WriteBytes(cs.Script)
+	bw.WriteVarUint(uint64(len(cs.ParamList)))
+	for k := range cs.ParamList {
+		bw.WriteLE(cs.ParamList[k])
 	}
-	bw.WriteLE(a.ReturnType)
-	bw.WriteBytes(a.Properties)
-	bw.WriteString(a.Name)
-	bw.WriteString(a.CodeVersion)
-	bw.WriteString(a.Author)
-	bw.WriteString(a.Email)
-	bw.WriteString(a.Description)
-	bw.WriteLE(a.HasStorage)
-	bw.WriteLE(a.HasDynamicInvoke)
+	bw.WriteLE(cs.ReturnType)
+	bw.WriteLE(cs.Properties)
+	bw.WriteString(cs.Name)
+	bw.WriteString(cs.CodeVersion)
+	bw.WriteString(cs.Author)
+	bw.WriteString(cs.Email)
+	bw.WriteString(cs.Description)
+}
+
+// putContractStateIntoStore puts given contract state into the given store.
+func putContractStateIntoStore(s storage.Store, cs *ContractState) error {
+	buf := io.NewBufBinWriter()
+	cs.EncodeBinary(buf.BinWriter)
+	if buf.Err != nil {
+		return buf.Err
+	}
+	key := storage.AppendPrefix(storage.STContract, cs.ScriptHash().Bytes())
+	return s.Put(key, buf.Bytes())
+}
+
+// deleteContractStateInStore deletes given contract state in the given store.
+func deleteContractStateInStore(s storage.Store, hash util.Uint160) error {
+	key := storage.AppendPrefix(storage.STContract, hash.Bytes())
+	return s.Delete(key)
 }
 
 // ScriptHash returns a contract script hash.
-func (a *ContractState) ScriptHash() util.Uint160 {
-	if a.scriptHash.Equals(util.Uint160{}) {
-		a.createHash()
+func (cs *ContractState) ScriptHash() util.Uint160 {
+	if cs.scriptHash.Equals(util.Uint160{}) {
+		cs.createHash()
 	}
-	return a.scriptHash
+	return cs.scriptHash
 }
 
 // createHash creates contract script hash.
-func (a *ContractState) createHash() {
-	a.scriptHash = hash.Hash160(a.Script)
+func (cs *ContractState) createHash() {
+	cs.scriptHash = hash.Hash160(cs.Script)
+}
+
+// HasStorage checks whether the contract has storage property set.
+func (cs *ContractState) HasStorage() bool {
+	return (cs.Properties & smartcontract.HasStorage) != 0
+}
+
+// HasDynamicInvoke checks whether the contract has dynamic invoke property set.
+func (cs *ContractState) HasDynamicInvoke() bool {
+	return (cs.Properties & smartcontract.HasDynamicInvoke) != 0
+}
+
+// IsPayable checks whether the contract has payable property set.
+func (cs *ContractState) IsPayable() bool {
+	return (cs.Properties & smartcontract.IsPayable) != 0
 }

pkg/core/contract_state_test.go

@@ -3,6 +3,7 @@ package core
 import (
 	"testing"
 
+	"github.com/CityOfZion/neo-go/pkg/core/storage"
 	"github.com/CityOfZion/neo-go/pkg/crypto/hash"
 	"github.com/CityOfZion/neo-go/pkg/io"
 	"github.com/CityOfZion/neo-go/pkg/smartcontract"
@@ -16,14 +17,12 @@ func TestEncodeDecodeContractState(t *testing.T) {
 		Script:      script,
 		ParamList:   []smartcontract.ParamType{smartcontract.StringType, smartcontract.IntegerType, smartcontract.Hash160Type},
 		ReturnType:  smartcontract.BoolType,
-		Properties:       []byte("smth"),
+		Properties:  smartcontract.HasStorage,
 		Name:        "Contracto",
 		CodeVersion: "1.0.0",
 		Author:      "Joe Random",
 		Email:       "joe@example.com",
 		Description: "Test contract",
-		HasStorage:       true,
-		HasDynamicInvoke: false,
 	}
 
 	assert.Equal(t, hash.Hash160(script), contract.ScriptHash())
@@ -37,3 +36,42 @@ func TestEncodeDecodeContractState(t *testing.T) {
 	assert.Equal(t, contract, contractDecoded)
 	assert.Equal(t, contract.ScriptHash(), contractDecoded.ScriptHash())
 }
+
+func TestContractStateProperties(t *testing.T) {
+	flaggedContract := ContractState{
+		Properties: smartcontract.HasStorage | smartcontract.HasDynamicInvoke | smartcontract.IsPayable,
+	}
+	nonFlaggedContract := ContractState{
+		ReturnType: smartcontract.BoolType,
+	}
+	assert.Equal(t, true, flaggedContract.HasStorage())
+	assert.Equal(t, true, flaggedContract.HasDynamicInvoke())
+	assert.Equal(t, true, flaggedContract.IsPayable())
+	assert.Equal(t, false, nonFlaggedContract.HasStorage())
+	assert.Equal(t, false, nonFlaggedContract.HasDynamicInvoke())
+	assert.Equal(t, false, nonFlaggedContract.IsPayable())
+}
+
+func TestPutGetDeleteContractState(t *testing.T) {
+	s := storage.NewMemoryStore()
+	script := []byte("testscript")
+
+	contract := &ContractState{
+		Script:      script,
+		ParamList:   []smartcontract.ParamType{smartcontract.StringType, smartcontract.IntegerType, smartcontract.Hash160Type},
+		ReturnType:  smartcontract.BoolType,
+		Properties:  smartcontract.HasStorage,
+		Name:        "Contracto",
+		CodeVersion: "1.0.0",
+		Author:      "Joe Random",
+		Email:       "joe@example.com",
+		Description: "Test contract",
+	}
+	assert.NoError(t, putContractStateIntoStore(s, contract))
+	csRead := getContractStateFromStore(s, contract.ScriptHash())
+	assert.NotNil(t, csRead)
+	assert.Equal(t, contract, csRead)
+	assert.NoError(t, deleteContractStateInStore(s, contract.ScriptHash()))
+	csRead2 := getContractStateFromStore(s, contract.ScriptHash())
+	assert.Nil(t, csRead2)
+}

pkg/core/helper_test.go

@@ -1,6 +1,7 @@
 package core
 
 import (
+	"context"
 	"encoding/hex"
 	"encoding/json"
 	"fmt"
@@ -8,46 +9,105 @@ import (
 	"testing"
 	"time"
 
+	"github.com/CityOfZion/neo-go/config"
+	"github.com/CityOfZion/neo-go/pkg/core/storage"
 	"github.com/CityOfZion/neo-go/pkg/core/transaction"
-	"github.com/CityOfZion/neo-go/pkg/crypto/hash"
+	"github.com/CityOfZion/neo-go/pkg/crypto/keys"
 	"github.com/CityOfZion/neo-go/pkg/io"
+	"github.com/CityOfZion/neo-go/pkg/smartcontract"
 	"github.com/CityOfZion/neo-go/pkg/util"
+	"github.com/stretchr/testify/require"
 )
 
+var newBlockPrevHash util.Uint256
+var unitTestNetCfg config.Config
+
+var privNetKeys = []string{
+	"KxyjQ8eUa4FHt3Gvioyt1Wz29cTUrE4eTqX3yFSk1YFCsPL8uNsY",
+	"KzfPUYDC9n2yf4fK5ro4C8KMcdeXtFuEnStycbZgX3GomiUsvX6W",
+	"KzgWE3u3EDp13XPXXuTKZxeJ3Gi8Bsm8f9ijY3ZsCKKRvZUo1Cdn",
+	"L2oEXKRAAMiPEZukwR5ho2S6SMeQLhcK9mF71ZnF7GvT8dU4Kkgz",
+}
+
+// newTestChain should be called before newBlock invocation to properly setup
+// global state.
+func newTestChain(t *testing.T) *Blockchain {
+	var err error
+	unitTestNetCfg, err = config.Load("../../config", config.ModeUnitTestNet)
+	if err != nil {
+		t.Fatal(err)
+	}
+	chain, err := NewBlockchain(storage.NewMemoryStore(), unitTestNetCfg.ProtocolConfiguration)
+	if err != nil {
+		t.Fatal(err)
+	}
+	go chain.Run(context.Background())
+	zeroHash, err := chain.GetHeader(chain.GetHeaderHash(0))
+	require.Nil(t, err)
+	newBlockPrevHash = zeroHash.Hash()
+	return chain
+}
+
 func newBlock(index uint32, txs ...*transaction.Transaction) *Block {
+	validators, _ := getValidators(unitTestNetCfg.ProtocolConfiguration)
+	vlen := len(validators)
+	valScript, _ := smartcontract.CreateMultiSigRedeemScript(
+		vlen-(vlen-1)/3,
+		validators,
+	)
+	witness := &transaction.Witness{
+		VerificationScript: valScript,
+	}
 	b := &Block{
 		BlockBase: BlockBase{
 			Version:       0,
-			PrevHash:      hash.Sha256([]byte("a")),
-			MerkleRoot:    hash.Sha256([]byte("b")),
-			Timestamp:     uint32(time.Now().UTC().Unix()),
+			PrevHash:      newBlockPrevHash,
+			Timestamp:     uint32(time.Now().UTC().Unix()) + index,
 			Index:         index,
 			ConsensusData: 1111,
-			NextConsensus: util.Uint160{},
-			Script: &transaction.Witness{
-				VerificationScript: []byte{0x0},
-				InvocationScript:   []byte{0x1},
-			},
+			NextConsensus: witness.ScriptHash(),
+			Script:        witness,
 		},
 		Transactions: txs,
 	}
-
+	_ = b.rebuildMerkleRoot()
 	b.createHash()
+	newBlockPrevHash = b.Hash()
 
+	invScript := make([]byte, 0)
+	for _, wif := range privNetKeys {
+		pKey, err := keys.NewPrivateKeyFromWIF(wif)
+		if err != nil {
+			panic(err)
+		}
+		b, err := b.getHashableData()
+		if err != nil {
+			panic(err)
+		}
+		sig, err := pKey.Sign(b)
+		if err != nil || len(sig) != 64 {
+			panic(err)
+		}
+		// 0x40 is PUSHBYTES64
+		invScript = append(invScript, 0x40)
+		invScript = append(invScript, sig...)
+	}
+	b.Script.InvocationScript = invScript
 	return b
 }
 
 func makeBlocks(n int) []*Block {
 	blocks := make([]*Block, n)
 	for i := 0; i < n; i++ {
-		blocks[i] = newBlock(uint32(i+1), newTX(transaction.MinerType))
+		blocks[i] = newBlock(uint32(i+1), newMinerTX())
 	}
 	return blocks
 }
 
-func newTX(t transaction.TXType) *transaction.Transaction {
+func newMinerTX() *transaction.Transaction {
 	return &transaction.Transaction{
-		Type: t,
+		Type: transaction.MinerType,
+		Data: &transaction.MinerTX{},
 	}
 }
 

pkg/core/interop_neo.go

@@ -0,0 +1,738 @@
+package core
+
+import (
+	"errors"
+	"fmt"
+	"math"
+
+	"github.com/CityOfZion/neo-go/pkg/core/transaction"
+	"github.com/CityOfZion/neo-go/pkg/crypto/keys"
+	"github.com/CityOfZion/neo-go/pkg/smartcontract"
+	"github.com/CityOfZion/neo-go/pkg/util"
+	"github.com/CityOfZion/neo-go/pkg/vm"
+	gherr "github.com/pkg/errors"
+)
+
+const (
+	// MaxContractScriptSize is the maximum script size for a contract.
+	MaxContractScriptSize = 1024 * 1024
+	// MaxContractParametersNum is the maximum number of parameters for a contract.
+	MaxContractParametersNum = 252
+	// MaxContractStringLen is the maximum length for contract metadata strings.
+	MaxContractStringLen = 252
+	// MaxAssetNameLen is the maximum length of asset name.
+	MaxAssetNameLen = 1024
+	// MaxAssetPrecision is the maximum precision of asset.
+	MaxAssetPrecision = 8
+	// BlocksPerYear is a multiplier for asset renewal.
+	BlocksPerYear = 2000000
+	// DefaultAssetLifetime is the default lifetime of an asset (which differs
+	// from assets created by register tx).
+	DefaultAssetLifetime = 1 + BlocksPerYear
+)
+
+// txInOut is used to pushed one key-value pair from References() onto the stack.
+type txInOut struct {
+	in  transaction.Input
+	out transaction.Output
+}
+
+// headerGetVersion returns version from the header.
+func (ic *interopContext) headerGetVersion(v *vm.VM) error {
+	header, err := popHeaderFromVM(v)
+	if err != nil {
+		return err
+	}
+	v.Estack().PushVal(header.Version)
+	return nil
+}
+
+// headerGetConsensusData returns consensus data from the header.
+func (ic *interopContext) headerGetConsensusData(v *vm.VM) error {
+	header, err := popHeaderFromVM(v)
+	if err != nil {
+		return err
+	}
+	v.Estack().PushVal(header.ConsensusData)
+	return nil
+}
+
+// headerGetMerkleRoot returns version from the header.
+func (ic *interopContext) headerGetMerkleRoot(v *vm.VM) error {
+	header, err := popHeaderFromVM(v)
+	if err != nil {
+		return err
+	}
+	v.Estack().PushVal(header.MerkleRoot.BytesReverse())
+	return nil
+}
+
+// headerGetNextConsensus returns version from the header.
+func (ic *interopContext) headerGetNextConsensus(v *vm.VM) error {
+	header, err := popHeaderFromVM(v)
+	if err != nil {
+		return err
+	}
+	v.Estack().PushVal(header.NextConsensus.BytesReverse())
+	return nil
+}
+
+// txGetAttributes returns current transaction attributes.
+func (ic *interopContext) txGetAttributes(v *vm.VM) error {
+	txInterface := v.Estack().Pop().Value()
+	tx, ok := txInterface.(*transaction.Transaction)
+	if !ok {
+		return errors.New("value is not a transaction")
+	}
+	if len(tx.Attributes) > vm.MaxArraySize {
+		return errors.New("too many attributes")
+	}
+	attrs := make([]vm.StackItem, 0, len(tx.Attributes))
+	for _, attr := range tx.Attributes {
+		attrs = append(attrs, vm.NewInteropItem(attr))
+	}
+	v.Estack().PushVal(attrs)
+	return nil
+}
+
+// txGetInputs returns current transaction inputs.
+func (ic *interopContext) txGetInputs(v *vm.VM) error {
+	txInterface := v.Estack().Pop().Value()
+	tx, ok := txInterface.(*transaction.Transaction)
+	if !ok {
+		return errors.New("value is not a transaction")
+	}
+	if len(tx.Inputs) > vm.MaxArraySize {
+		return errors.New("too many inputs")
+	}
+	inputs := make([]vm.StackItem, 0, len(tx.Inputs))
+	for _, input := range tx.Inputs {
+		inputs = append(inputs, vm.NewInteropItem(input))
+	}
+	v.Estack().PushVal(inputs)
+	return nil
+}
+
+// txGetOutputs returns current transaction outputs.
+func (ic *interopContext) txGetOutputs(v *vm.VM) error {
+	txInterface := v.Estack().Pop().Value()
+	tx, ok := txInterface.(*transaction.Transaction)
+	if !ok {
+		return errors.New("value is not a transaction")
+	}
+	if len(tx.Outputs) > vm.MaxArraySize {
+		return errors.New("too many outputs")
+	}
+	outputs := make([]vm.StackItem, 0, len(tx.Outputs))
+	for _, output := range tx.Outputs {
+		outputs = append(outputs, vm.NewInteropItem(output))
+	}
+	v.Estack().PushVal(outputs)
+	return nil
+}
+
+// txGetReferences returns current transaction references.
+func (ic *interopContext) txGetReferences(v *vm.VM) error {
+	txInterface := v.Estack().Pop().Value()
+	tx, ok := txInterface.(*transaction.Transaction)
+	if !ok {
+		return fmt.Errorf("type mismatch: %T is not a Transaction", txInterface)
+	}
+	refs := ic.bc.References(tx)
+	if len(refs) > vm.MaxArraySize {
+		return errors.New("too many references")
+	}
+
+	stackrefs := make([]vm.StackItem, 0, len(refs))
+	for k, v := range refs {
+		tio := txInOut{k, *v}
+		stackrefs = append(stackrefs, vm.NewInteropItem(tio))
+	}
+	v.Estack().PushVal(stackrefs)
+	return nil
+}
+
+// txGetType returns current transaction type.
+func (ic *interopContext) txGetType(v *vm.VM) error {
+	txInterface := v.Estack().Pop().Value()
+	tx, ok := txInterface.(*transaction.Transaction)
+	if !ok {
+		return errors.New("value is not a transaction")
+	}
+	v.Estack().PushVal(int(tx.Type))
+	return nil
+}
+
+// txGetUnspentCoins returns current transaction unspent coins.
+func (ic *interopContext) txGetUnspentCoins(v *vm.VM) error {
+	txInterface := v.Estack().Pop().Value()
+	tx, ok := txInterface.(*transaction.Transaction)
+	if !ok {
+		return errors.New("value is not a transaction")
+	}
+	ucs := ic.bc.GetUnspentCoinState(tx.Hash())
+	if ucs == nil {
+		return errors.New("no unspent coin state found")
+	}
+	v.Estack().PushVal(vm.NewInteropItem(ucs))
+	return nil
+}
+
+// txGetWitnesses returns current transaction witnesses.
+func (ic *interopContext) txGetWitnesses(v *vm.VM) error {
+	txInterface := v.Estack().Pop().Value()
+	tx, ok := txInterface.(*transaction.Transaction)
+	if !ok {
+		return errors.New("value is not a transaction")
+	}
+	if len(tx.Scripts) > vm.MaxArraySize {
+		return errors.New("too many outputs")
+	}
+	scripts := make([]vm.StackItem, 0, len(tx.Scripts))
+	for _, script := range tx.Scripts {
+		scripts = append(scripts, vm.NewInteropItem(script))
+	}
+	v.Estack().PushVal(scripts)
+	return nil
+}
+
+// popInputFromVM returns transaction.Input from the first estack element.
+func popInputFromVM(v *vm.VM) (*transaction.Input, error) {
+	inInterface := v.Estack().Pop().Value()
+	input, ok := inInterface.(*transaction.Input)
+	if !ok {
+		txio, ok := inInterface.(txInOut)
+		if !ok {
+			return nil, fmt.Errorf("type mismatch: %T is not an Input or txInOut", inInterface)
+		}
+		input = &txio.in
+	}
+	return input, nil
+}
+
+// inputGetHash returns hash from the given input.
+func (ic *interopContext) inputGetHash(v *vm.VM) error {
+	input, err := popInputFromVM(v)
+	if err != nil {
+		return err
+	}
+	v.Estack().PushVal(input.PrevHash.Bytes())
+	return nil
+}
+
+// inputGetIndex returns index from the given input.
+func (ic *interopContext) inputGetIndex(v *vm.VM) error {
+	input, err := popInputFromVM(v)
+	if err != nil {
+		return err
+	}
+	v.Estack().PushVal(input.PrevIndex)
+	return nil
+}
+
+// popOutputFromVM returns transaction.Input from the first estack element.
+func popOutputFromVM(v *vm.VM) (*transaction.Output, error) {
+	outInterface := v.Estack().Pop().Value()
+	output, ok := outInterface.(*transaction.Output)
+	if !ok {
+		txio, ok := outInterface.(txInOut)
+		if !ok {
+			return nil, fmt.Errorf("type mismatch: %T is not an Output or txInOut", outInterface)
+		}
+		output = &txio.out
+	}
+	return output, nil
+}
+
+// outputGetAssetId returns asset ID from the given output.
+func (ic *interopContext) outputGetAssetID(v *vm.VM) error {
+	output, err := popOutputFromVM(v)
+	if err != nil {
+		return err
+	}
+	v.Estack().PushVal(output.AssetID.Bytes())
+	return nil
+}
+
+// outputGetScriptHash returns scripthash from the given output.
+func (ic *interopContext) outputGetScriptHash(v *vm.VM) error {
+	output, err := popOutputFromVM(v)
+	if err != nil {
+		return err
+	}
+	v.Estack().PushVal(output.ScriptHash.Bytes())
+	return nil
+}
+
+// outputGetValue returns value (amount) from the given output.
+func (ic *interopContext) outputGetValue(v *vm.VM) error {
+	output, err := popOutputFromVM(v)
+	if err != nil {
+		return err
+	}
+	v.Estack().PushVal(int64(output.Amount))
+	return nil
+}
+
+// attrGetData returns tx attribute data.
+func (ic *interopContext) attrGetData(v *vm.VM) error {
+	attrInterface := v.Estack().Pop().Value()
+	attr, ok := attrInterface.(*transaction.Attribute)
+	if !ok {
+		return fmt.Errorf("%T is not an attribute", attr)
+	}
+	v.Estack().PushVal(attr.Data)
+	return nil
+}
+
+// attrGetData returns tx attribute usage field.
+func (ic *interopContext) attrGetUsage(v *vm.VM) error {
+	attrInterface := v.Estack().Pop().Value()
+	attr, ok := attrInterface.(*transaction.Attribute)
+	if !ok {
+		return fmt.Errorf("%T is not an attribute", attr)
+	}
+	v.Estack().PushVal(int(attr.Usage))
+	return nil
+}
+
+// bcGetAccount returns or creates an account.
+func (ic *interopContext) bcGetAccount(v *vm.VM) error {
+	accbytes := v.Estack().Pop().Bytes()
+	acchash, err := util.Uint160DecodeBytes(accbytes)
+	if err != nil {
+		return err
+	}
+	acc := ic.bc.GetAccountState(acchash)
+	if acc == nil {
+		acc = NewAccountState(acchash)
+	}
+	v.Estack().PushVal(vm.NewInteropItem(acc))
+	return nil
+}
+
+// bcGetAsset returns an asset.
+func (ic *interopContext) bcGetAsset(v *vm.VM) error {
+	asbytes := v.Estack().Pop().Bytes()
+	ashash, err := util.Uint256DecodeBytes(asbytes)
+	if err != nil {
+		return err
+	}
+	as := ic.bc.GetAssetState(ashash)
+	if as == nil {
+		return errors.New("asset not found")
+	}
+	v.Estack().PushVal(vm.NewInteropItem(as))
+	return nil
+}
+
+// accountGetBalance returns balance for a given account.
+func (ic *interopContext) accountGetBalance(v *vm.VM) error {
+	accInterface := v.Estack().Pop().Value()
+	acc, ok := accInterface.(*AccountState)
+	if !ok {
+		return fmt.Errorf("%T is not an account state", acc)
+	}
+	asbytes := v.Estack().Pop().Bytes()
+	ashash, err := util.Uint256DecodeBytes(asbytes)
+	if err != nil {
+		return err
+	}
+	balance, ok := acc.Balances[ashash]
+	if !ok {
+		balance = util.Fixed8(0)
+	}
+	v.Estack().PushVal(int64(balance))
+	return nil
+}
+
+// accountGetScriptHash returns script hash of a given account.
+func (ic *interopContext) accountGetScriptHash(v *vm.VM) error {
+	accInterface := v.Estack().Pop().Value()
+	acc, ok := accInterface.(*AccountState)
+	if !ok {
+		return fmt.Errorf("%T is not an account state", acc)
+	}
+	v.Estack().PushVal(acc.ScriptHash.Bytes())
+	return nil
+}
+
+// accountGetVotes returns votes of a given account.
+func (ic *interopContext) accountGetVotes(v *vm.VM) error {
+	accInterface := v.Estack().Pop().Value()
+	acc, ok := accInterface.(*AccountState)
+	if !ok {
+		return fmt.Errorf("%T is not an account state", acc)
+	}
+	if len(acc.Votes) > vm.MaxArraySize {
+		return errors.New("too many votes")
+	}
+	votes := make([]vm.StackItem, 0, len(acc.Votes))
+	for _, key := range acc.Votes {
+		votes = append(votes, vm.NewByteArrayItem(key.Bytes()))
+	}
+	v.Estack().PushVal(votes)
+	return nil
+}
+
+// accountIsStandard checks whether given account is standard.
+func (ic *interopContext) accountIsStandard(v *vm.VM) error {
+	accbytes := v.Estack().Pop().Bytes()
+	acchash, err := util.Uint160DecodeBytes(accbytes)
+	if err != nil {
+		return err
+	}
+	contract := ic.bc.GetContractState(acchash)
+	res := contract == nil || vm.IsStandardContract(contract.Script)
+	v.Estack().PushVal(res)
+	return nil
+}
+
+/*
+// storageFind finds stored key-value pair.
+func (ic *interopContext) storageFind(v *vm.VM) error {
+	stcInterface := v.Estack().Pop().Value()
+	stc, ok := stcInterface.(*StorageContext)
+	if !ok {
+		return fmt.Errorf("%T is not a StorageContext", stcInterface)
+	}
+	err := ic.checkStorageContext(stc)
+	if err != nil {
+		return err
+	}
+	prefix := string(v.Estack().Pop().Bytes())
+	siMap, err := ic.bc.GetStorageItems(stc.ScriptHash)
+	if err != nil {
+		return err
+	}
+	for k, v := range siMap {
+		if strings.HasPrefix(k, prefix) {
+			_ = v
+			panic("TODO")
+		}
+	}
+
+	return nil
+}
+*/
+// createContractStateFromVM pops all contract state elements from the VM
+// evaluation stack, does a lot of checks and returns ContractState if it
+// succeedes.
+func (ic *interopContext) createContractStateFromVM(v *vm.VM) (*ContractState, error) {
+	if ic.trigger != 0x10 {
+		return nil, errors.New("can't create contract when not triggered by an application")
+	}
+	script := v.Estack().Pop().Bytes()
+	if len(script) > MaxContractScriptSize {
+		return nil, errors.New("the script is too big")
+	}
+	paramBytes := v.Estack().Pop().Bytes()
+	if len(paramBytes) > MaxContractParametersNum {
+		return nil, errors.New("too many parameters for a script")
+	}
+	paramList := make([]smartcontract.ParamType, len(paramBytes))
+	for k, v := range paramBytes {
+		paramList[k] = smartcontract.ParamType(v)
+	}
+	retType := smartcontract.ParamType(v.Estack().Pop().BigInt().Int64())
+	properties := smartcontract.PropertyState(v.Estack().Pop().BigInt().Int64())
+	name := v.Estack().Pop().Bytes()
+	if len(name) > MaxContractStringLen {
+		return nil, errors.New("too big name")
+	}
+	version := v.Estack().Pop().Bytes()
+	if len(version) > MaxContractStringLen {
+		return nil, errors.New("too big version")
+	}
+	author := v.Estack().Pop().Bytes()
+	if len(author) > MaxContractStringLen {
+		return nil, errors.New("too big author")
+	}
+	email := v.Estack().Pop().Bytes()
+	if len(email) > MaxContractStringLen {
+		return nil, errors.New("too big email")
+	}
+	desc := v.Estack().Pop().Bytes()
+	if len(desc) > MaxContractStringLen {
+		return nil, errors.New("too big description")
+	}
+	contract := &ContractState{
+		Script:      script,
+		ParamList:   paramList,
+		ReturnType:  retType,
+		Properties:  properties,
+		Name:        string(name),
+		CodeVersion: string(version),
+		Author:      string(author),
+		Email:       string(email),
+		Description: string(desc),
+	}
+	return contract, nil
+}
+
+// contractCreate creates a contract.
+func (ic *interopContext) contractCreate(v *vm.VM) error {
+	newcontract, err := ic.createContractStateFromVM(v)
+	if err != nil {
+		return nil
+	}
+	contract := ic.bc.GetContractState(newcontract.ScriptHash())
+	if contract == nil {
+		contract = newcontract
+		err := putContractStateIntoStore(ic.mem, contract)
+		if err != nil {
+			return err
+		}
+	}
+	v.Estack().PushVal(vm.NewInteropItem(contract))
+	return nil
+}
+
+// contractGetScript returns a script associated with a contract.
+func (ic *interopContext) contractGetScript(v *vm.VM) error {
+	csInterface := v.Estack().Pop().Value()
+	cs, ok := csInterface.(*ContractState)
+	if !ok {
+		return fmt.Errorf("%T is not a contract state", cs)
+	}
+	v.Estack().PushVal(cs.Script)
+	return nil
+}
+
+// contractIsPayable returns whether contract is payable.
+func (ic *interopContext) contractIsPayable(v *vm.VM) error {
+	csInterface := v.Estack().Pop().Value()
+	cs, ok := csInterface.(*ContractState)
+	if !ok {
+		return fmt.Errorf("%T is not a contract state", cs)
+	}
+	v.Estack().PushVal(cs.IsPayable())
+	return nil
+}
+
+// contractMigrate migrates a contract.
+func (ic *interopContext) contractMigrate(v *vm.VM) error {
+	newcontract, err := ic.createContractStateFromVM(v)
+	if err != nil {
+		return nil
+	}
+	contract := ic.bc.GetContractState(newcontract.ScriptHash())
+	if contract == nil {
+		contract = newcontract
+		err := putContractStateIntoStore(ic.mem, contract)
+		if err != nil {
+			return err
+		}
+		if contract.HasStorage() {
+			hash := getContextScriptHash(v, 0)
+			siMap, err := ic.bc.GetStorageItems(hash)
+			if err != nil {
+				return err
+			}
+			for k, v := range siMap {
+				v.IsConst = false
+				_ = putStorageItemIntoStore(ic.mem, hash, []byte(k), v)
+			}
+		}
+	}
+	v.Estack().PushVal(vm.NewInteropItem(contract))
+	return ic.contractDestroy(v)
+}
+
+// assetCreate creates an asset.
+func (ic *interopContext) assetCreate(v *vm.VM) error {
+	if ic.trigger != 0x10 {
+		return errors.New("can't create asset when not triggered by an application")
+	}
+	atype := transaction.AssetType(v.Estack().Pop().BigInt().Int64())
+	switch atype {
+	case transaction.Currency, transaction.Share, transaction.Invoice, transaction.Token:
+		// ok
+	default:
+		return fmt.Errorf("wrong asset type: %x", atype)
+	}
+	name := string(v.Estack().Pop().Bytes())
+	if len(name) > MaxAssetNameLen {
+		return errors.New("too big name")
+	}
+	amount := util.Fixed8(v.Estack().Pop().BigInt().Int64())
+	if amount == util.Fixed8(0) {
+		return errors.New("asset amount can't be zero")
+	}
+	if amount < -util.Satoshi() {
+		return errors.New("asset amount can't be negative (except special -Satoshi value")
+	}
+	if atype == transaction.Invoice && amount != -util.Satoshi() {
+		return errors.New("invoice assets can only have -Satoshi amount")
+	}
+	precision := byte(v.Estack().Pop().BigInt().Int64())
+	if precision > MaxAssetPrecision {
+		return fmt.Errorf("can't have asset precision of more than %d", MaxAssetPrecision)
+	}
+	if atype == transaction.Share && precision != 0 {
+		return errors.New("share assets can only have zero precision")
+	}
+	if amount != -util.Satoshi() && (int64(amount)%int64(math.Pow10(int(MaxAssetPrecision-precision))) != 0) {
+		return errors.New("given asset amount has fractional component")
+	}
+	owner := &keys.PublicKey{}
+	err := owner.DecodeBytes(v.Estack().Pop().Bytes())
+	if err != nil {
+		return gherr.Wrap(err, "failed to get owner key")
+	}
+	if owner.IsInfinity() {
+		return errors.New("can't have infinity as an owner key")
+	}
+	witnessOk, err := ic.checkKeyedWitness(owner)
+	if err != nil {
+		return err
+	}
+	if !witnessOk {
+		return errors.New("witness check didn't succeed")
+	}
+	admin, err := util.Uint160DecodeBytes(v.Estack().Pop().Bytes())
+	if err != nil {
+		return gherr.Wrap(err, "failed to get admin")
+	}
+	issuer, err := util.Uint160DecodeBytes(v.Estack().Pop().Bytes())
+	if err != nil {
+		return gherr.Wrap(err, "failed to get issuer")
+	}
+	asset := &AssetState{
+		ID:         ic.tx.Hash(),
+		AssetType:  atype,
+		Name:       name,
+		Amount:     amount,
+		Precision:  precision,
+		Owner:      owner,
+		Admin:      admin,
+		Issuer:     issuer,
+		Expiration: ic.bc.BlockHeight() + DefaultAssetLifetime,
+	}
+	err = putAssetStateIntoStore(ic.mem, asset)
+	if err != nil {
+		return gherr.Wrap(err, "failed to store asset")
+	}
+	v.Estack().PushVal(vm.NewInteropItem(asset))
+	return nil
+}
+
+// assetGetAdmin returns asset admin.
+func (ic *interopContext) assetGetAdmin(v *vm.VM) error {
+	asInterface := v.Estack().Pop().Value()
+	as, ok := asInterface.(*AssetState)
+	if !ok {
+		return fmt.Errorf("%T is not an asset state", as)
+	}
+	v.Estack().PushVal(as.Admin.Bytes())
+	return nil
+}
+
+// assetGetAmount returns the overall amount of asset available.
+func (ic *interopContext) assetGetAmount(v *vm.VM) error {
+	asInterface := v.Estack().Pop().Value()
+	as, ok := asInterface.(*AssetState)
+	if !ok {
+		return fmt.Errorf("%T is not an asset state", as)
+	}
+	v.Estack().PushVal(int64(as.Amount))
+	return nil
+}
+
+// assetGetAssetId returns the id of an asset.
+func (ic *interopContext) assetGetAssetID(v *vm.VM) error {
+	asInterface := v.Estack().Pop().Value()
+	as, ok := asInterface.(*AssetState)
+	if !ok {
+		return fmt.Errorf("%T is not an asset state", as)
+	}
+	v.Estack().PushVal(as.ID.Bytes())
+	return nil
+}
+
+// assetGetAssetType returns type of an asset.
+func (ic *interopContext) assetGetAssetType(v *vm.VM) error {
+	asInterface := v.Estack().Pop().Value()
+	as, ok := asInterface.(*AssetState)
+	if !ok {
+		return fmt.Errorf("%T is not an asset state", as)
+	}
+	v.Estack().PushVal(int(as.AssetType))
+	return nil
+}
+
+// assetGetAvailable returns available (not yet issued) amount of asset.
+func (ic *interopContext) assetGetAvailable(v *vm.VM) error {
+	asInterface := v.Estack().Pop().Value()
+	as, ok := asInterface.(*AssetState)
+	if !ok {
+		return fmt.Errorf("%T is not an asset state", as)
+	}
+	v.Estack().PushVal(int(as.Available))
+	return nil
+}
+
+// assetGetIssuer returns issuer of an asset.
+func (ic *interopContext) assetGetIssuer(v *vm.VM) error {
+	asInterface := v.Estack().Pop().Value()
+	as, ok := asInterface.(*AssetState)
+	if !ok {
+		return fmt.Errorf("%T is not an asset state", as)
+	}
+	v.Estack().PushVal(as.Issuer.Bytes())
+	return nil
+}
+
+// assetGetOwner returns owner of an asset.
+func (ic *interopContext) assetGetOwner(v *vm.VM) error {
+	asInterface := v.Estack().Pop().Value()
+	as, ok := asInterface.(*AssetState)
+	if !ok {
+		return fmt.Errorf("%T is not an asset state", as)
+	}
+	v.Estack().PushVal(as.Owner.Bytes())
+	return nil
+}
+
+// assetGetPrecision returns precision used to measure this asset.
+func (ic *interopContext) assetGetPrecision(v *vm.VM) error {
+	asInterface := v.Estack().Pop().Value()
+	as, ok := asInterface.(*AssetState)
+	if !ok {
+		return fmt.Errorf("%T is not an asset state", as)
+	}
+	v.Estack().PushVal(int(as.Precision))
+	return nil
+}
+
+// assetRenew updates asset expiration date.
+func (ic *interopContext) assetRenew(v *vm.VM) error {
+	if ic.trigger != 0x10 {
+		return errors.New("can't create asset when not triggered by an application")
+	}
+	asInterface := v.Estack().Pop().Value()
+	as, ok := asInterface.(*AssetState)
+	if !ok {
+		return fmt.Errorf("%T is not an asset state", as)
+	}
+	years := byte(v.Estack().Pop().BigInt().Int64())
+	// Not sure why C# code regets an asset from the Store, but we also do it.
+	asset := ic.bc.GetAssetState(as.ID)
+	if asset == nil {
+		return errors.New("can't renew non-existent asset")
+	}
+	if asset.Expiration < ic.bc.BlockHeight()+1 {
+		asset.Expiration = ic.bc.BlockHeight() + 1
+	}
+	expiration := uint64(asset.Expiration) + uint64(years)*BlocksPerYear
+	if expiration > math.MaxUint32 {
+		expiration = math.MaxUint32
+	}
+	asset.Expiration = uint32(expiration)
+	err := putAssetStateIntoStore(ic.mem, asset)
+	if err != nil {
+		return gherr.Wrap(err, "failed to store asset")
+	}
+	v.Estack().PushVal(expiration)
+	return nil
+}

pkg/core/interop_system.go

@@ -0,0 +1,583 @@
+package core
+
+import (
+	"errors"
+	"fmt"
+	"math"
+
+	"github.com/CityOfZion/neo-go/pkg/core/transaction"
+	"github.com/CityOfZion/neo-go/pkg/crypto/hash"
+	"github.com/CityOfZion/neo-go/pkg/crypto/keys"
+	"github.com/CityOfZion/neo-go/pkg/smartcontract"
+	"github.com/CityOfZion/neo-go/pkg/util"
+	"github.com/CityOfZion/neo-go/pkg/vm"
+	gherr "github.com/pkg/errors"
+	log "github.com/sirupsen/logrus"
+)
+
+const (
+	// MaxStorageKeyLen is the maximum length of a key for storage items.
+	MaxStorageKeyLen = 1024
+)
+
+// StorageContext contains storing script hash and read/write flag, it's used as
+// a context for storage manipulation functions.
+type StorageContext struct {
+	ScriptHash util.Uint160
+	ReadOnly   bool
+}
+
+// getBlockHashFromElement converts given vm.Element to block hash using given
+// Blockchainer if needed. Interop functions accept both block numbers and
+// block hashes as parameters, thus this function is needed.
+func getBlockHashFromElement(bc Blockchainer, element *vm.Element) (util.Uint256, error) {
+	var hash util.Uint256
+	hashbytes := element.Bytes()
+	if len(hashbytes) <= 5 {
+		hashint := element.BigInt().Int64()
+		if hashint < 0 || hashint > math.MaxUint32 {
+			return hash, errors.New("bad block index")
+		}
+		hash = bc.GetHeaderHash(int(hashint))
+	} else {
+		return util.Uint256DecodeReverseBytes(hashbytes)
+	}
+	return hash, nil
+}
+
+// bcGetBlock returns current block.
+func (ic *interopContext) bcGetBlock(v *vm.VM) error {
+	hash, err := getBlockHashFromElement(ic.bc, v.Estack().Pop())
+	if err != nil {
+		return err
+	}
+	block, err := ic.bc.GetBlock(hash)
+	if err != nil {
+		v.Estack().PushVal([]byte{})
+	} else {
+		v.Estack().PushVal(vm.NewInteropItem(block))
+	}
+	return nil
+}
+
+// bcGetContract returns contract.
+func (ic *interopContext) bcGetContract(v *vm.VM) error {
+	hashbytes := v.Estack().Pop().Bytes()
+	hash, err := util.Uint160DecodeBytes(hashbytes)
+	if err != nil {
+		return err
+	}
+	cs := ic.bc.GetContractState(hash)
+	if cs == nil {
+		v.Estack().PushVal([]byte{})
+	} else {
+		v.Estack().PushVal(vm.NewInteropItem(cs))
+	}
+	return nil
+}
+
+// bcGetHeader returns block header.
+func (ic *interopContext) bcGetHeader(v *vm.VM) error {
+	hash, err := getBlockHashFromElement(ic.bc, v.Estack().Pop())
+	if err != nil {
+		return err
+	}
+	header, err := ic.bc.GetHeader(hash)
+	if err != nil {
+		v.Estack().PushVal([]byte{})
+	} else {
+		v.Estack().PushVal(vm.NewInteropItem(header))
+	}
+	return nil
+}
+
+// bcGetHeight returns blockchain height.
+func (ic *interopContext) bcGetHeight(v *vm.VM) error {
+	v.Estack().PushVal(ic.bc.BlockHeight())
+	return nil
+}
+
+// getTransactionAndHeight gets parameter from the vm evaluation stack and
+// returns transaction and its height if it's present in the blockchain.
+func getTransactionAndHeight(bc Blockchainer, v *vm.VM) (*transaction.Transaction, uint32, error) {
+	hashbytes := v.Estack().Pop().Bytes()
+	hash, err := util.Uint256DecodeReverseBytes(hashbytes)
+	if err != nil {
+		return nil, 0, err
+	}
+	return bc.GetTransaction(hash)
+}
+
+// bcGetTransaction returns transaction.
+func (ic *interopContext) bcGetTransaction(v *vm.VM) error {
+	tx, _, err := getTransactionAndHeight(ic.bc, v)
+	if err != nil {
+		return err
+	}
+	v.Estack().PushVal(vm.NewInteropItem(tx))
+	return nil
+}
+
+// bcGetTransactionHeight returns transaction height.
+func (ic *interopContext) bcGetTransactionHeight(v *vm.VM) error {
+	_, h, err := getTransactionAndHeight(ic.bc, v)
+	if err != nil {
+		return err
+	}
+	v.Estack().PushVal(h)
+	return nil
+}
+
+// popHeaderFromVM returns pointer to Header or error. It's main feature is
+// proper treatment of Block structure, because C# code implicitly assumes
+// that header APIs can also operate on blocks.
+func popHeaderFromVM(v *vm.VM) (*Header, error) {
+	iface := v.Estack().Pop().Value()
+	header, ok := iface.(*Header)
+	if !ok {
+		block, ok := iface.(*Block)
+		if !ok {
+			return nil, errors.New("value is not a header or block")
+		}
+		return block.Header(), nil
+	}
+	return header, nil
+}
+
+// headerGetIndex returns block index from the header.
+func (ic *interopContext) headerGetIndex(v *vm.VM) error {
+	header, err := popHeaderFromVM(v)
+	if err != nil {
+		return err
+	}
+	v.Estack().PushVal(header.Index)
+	return nil
+}
+
+// headerGetHash returns header hash of the passed header.
+func (ic *interopContext) headerGetHash(v *vm.VM) error {
+	header, err := popHeaderFromVM(v)
+	if err != nil {
+		return err
+	}
+	v.Estack().PushVal(header.Hash().BytesReverse())
+	return nil
+}
+
+// headerGetPrevHash returns previous header hash of the passed header.
+func (ic *interopContext) headerGetPrevHash(v *vm.VM) error {
+	header, err := popHeaderFromVM(v)
+	if err != nil {
+		return err
+	}
+	v.Estack().PushVal(header.PrevHash.BytesReverse())
+	return nil
+}
+
+// headerGetTimestamp returns timestamp of the passed header.
+func (ic *interopContext) headerGetTimestamp(v *vm.VM) error {
+	header, err := popHeaderFromVM(v)
+	if err != nil {
+		return err
+	}
+	v.Estack().PushVal(header.Timestamp)
+	return nil
+}
+
+// blockGetTransactionCount returns transactions count in the given block.
+func (ic *interopContext) blockGetTransactionCount(v *vm.VM) error {
+	blockInterface := v.Estack().Pop().Value()
+	block, ok := blockInterface.(*Block)
+	if !ok {
+		return errors.New("value is not a block")
+	}
+	v.Estack().PushVal(len(block.Transactions))
+	return nil
+}
+
+// blockGetTransactions returns transactions from the given block.
+func (ic *interopContext) blockGetTransactions(v *vm.VM) error {
+	blockInterface := v.Estack().Pop().Value()
+	block, ok := blockInterface.(*Block)
+	if !ok {
+		return errors.New("value is not a block")
+	}
+	if len(block.Transactions) > vm.MaxArraySize {
+		return errors.New("too many transactions")
+	}
+	txes := make([]vm.StackItem, 0, len(block.Transactions))
+	for _, tx := range block.Transactions {
+		txes = append(txes, vm.NewInteropItem(tx))
+	}
+	v.Estack().PushVal(txes)
+	return nil
+}
+
+// blockGetTransaction returns transaction with the given number from the given
+// block.
+func (ic *interopContext) blockGetTransaction(v *vm.VM) error {
+	blockInterface := v.Estack().Pop().Value()
+	block, ok := blockInterface.(*Block)
+	if !ok {
+		return errors.New("value is not a block")
+	}
+	index := v.Estack().Pop().BigInt().Int64()
+	if index < 0 || index >= int64(len(block.Transactions)) {
+		return errors.New("wrong transaction index")
+	}
+	tx := block.Transactions[index]
+	v.Estack().PushVal(vm.NewInteropItem(tx))
+	return nil
+}
+
+// txGetHash returns transaction's hash.
+func (ic *interopContext) txGetHash(v *vm.VM) error {
+	txInterface := v.Estack().Pop().Value()
+	tx, ok := txInterface.(*transaction.Transaction)
+	if !ok {
+		return errors.New("value is not a transaction")
+	}
+	v.Estack().PushVal(tx.Hash().BytesReverse())
+	return nil
+}
+
+// engineGetScriptContainer returns transaction that contains the script being
+// run.
+func (ic *interopContext) engineGetScriptContainer(v *vm.VM) error {
+	v.Estack().PushVal(vm.NewInteropItem(ic.tx))
+	return nil
+}
+
+// pushContextScriptHash returns script hash of the invocation stack element
+// number n.
+func getContextScriptHash(v *vm.VM, n int) util.Uint160 {
+	ctxIface := v.Istack().Peek(n).Value()
+	ctx := ctxIface.(*vm.Context)
+	return hash.Hash160(ctx.Program())
+}
+
+// pushContextScriptHash pushes to evaluation stack the script hash of the
+// invocation stack element number n.
+func pushContextScriptHash(v *vm.VM, n int) error {
+	h := getContextScriptHash(v, n)
+	v.Estack().PushVal(h.Bytes())
+	return nil
+}
+
+// engineGetExecutingScriptHash returns executing script hash.
+func (ic *interopContext) engineGetExecutingScriptHash(v *vm.VM) error {
+	return pushContextScriptHash(v, 0)
+}
+
+// engineGetCallingScriptHash returns calling script hash.
+func (ic *interopContext) engineGetCallingScriptHash(v *vm.VM) error {
+	return pushContextScriptHash(v, 1)
+}
+
+// engineGetEntryScriptHash returns entry script hash.
+func (ic *interopContext) engineGetEntryScriptHash(v *vm.VM) error {
+	return pushContextScriptHash(v, v.Istack().Len()-1)
+}
+
+// runtimePlatform returns the name of the platform.
+func (ic *interopContext) runtimePlatform(v *vm.VM) error {
+	v.Estack().PushVal([]byte("NEO"))
+	return nil
+}
+
+// runtimeGetTrigger returns the script trigger.
+func (ic *interopContext) runtimeGetTrigger(v *vm.VM) error {
+	v.Estack().PushVal(ic.trigger)
+	return nil
+}
+
+// checkHashedWitness checks given hash against current list of script hashes
+// for verifying in the interop context.
+func (ic *interopContext) checkHashedWitness(hash util.Uint160) (bool, error) {
+	hashes, err := ic.bc.GetScriptHashesForVerifying(ic.tx)
+	if err != nil {
+		return false, gherr.Wrap(err, "failed to get script hashes")
+	}
+	for _, v := range hashes {
+		if hash.Equals(v) {
+			return true, nil
+		}
+	}
+	return false, nil
+}
+
+// checkKeyedWitness checks hash of signature check contract with a given public
+// key against current list of script hashes for verifying in the interop context.
+func (ic *interopContext) checkKeyedWitness(key *keys.PublicKey) (bool, error) {
+	script, err := smartcontract.CreateSignatureRedeemScript(key)
+	if err != nil {
+		return false, gherr.Wrap(err, "failed to create signature script for a key")
+	}
+	return ic.checkHashedWitness(hash.Hash160(script))
+}
+
+// runtimeCheckWitness should check witnesses.
+func (ic *interopContext) runtimeCheckWitness(v *vm.VM) error {
+	var res bool
+	var err error
+
+	hashOrKey := v.Estack().Pop().Bytes()
+	hash, err := util.Uint160DecodeBytes(hashOrKey)
+	if err != nil {
+		key := &keys.PublicKey{}
+		err = key.DecodeBytes(hashOrKey)
+		if err != nil {
+			return errors.New("parameter given is neither a key nor a hash")
+		}
+		res, err = ic.checkKeyedWitness(key)
+	} else {
+		res, err = ic.checkHashedWitness(hash)
+	}
+	if err != nil {
+		return gherr.Wrap(err, "failed to check")
+	}
+	v.Estack().PushVal(res)
+	return nil
+}
+
+// runtimeNotify should pass stack item to the notify plugin to handle it, but
+// in neo-go the only meaningful thing to do here is to log.
+func (ic *interopContext) runtimeNotify(v *vm.VM) error {
+	msg := fmt.Sprintf("%q", v.Estack().Pop().Bytes())
+	log.Infof("script %s notifies: %s", getContextScriptHash(v, 0), msg)
+	return nil
+}
+
+// runtimeLog log the message passed.
+func (ic *interopContext) runtimeLog(v *vm.VM) error {
+	msg := fmt.Sprintf("%q", v.Estack().Pop().Bytes())
+	log.Infof("script %s logs: %s", getContextScriptHash(v, 0), msg)
+	return nil
+}
+
+// runtimeGetTime returns timestamp of the block being verified, or the latest
+// one in the blockchain if no block is given to interopContext.
+func (ic *interopContext) runtimeGetTime(v *vm.VM) error {
+	var header *Header
+	if ic.block == nil {
+		var err error
+		header, err = ic.bc.GetHeader(ic.bc.CurrentBlockHash())
+		if err != nil {
+			return err
+		}
+	} else {
+		header = ic.block.Header()
+	}
+	v.Estack().PushVal(header.Timestamp)
+	return nil
+}
+
+/*
+// runtimeSerialize should serialize given stack item.
+func (ic *interopContext) runtimeSerialize(v *vm.VM) error {
+	panic("TODO")
+}
+
+// runtimeDeserialize should deserialize given stack item.
+func (ic *interopContext) runtimeDeserialize(v *vm.VM) error {
+	panic("TODO")
+}
+*/
+func (ic *interopContext) checkStorageContext(stc *StorageContext) error {
+	contract := ic.bc.GetContractState(stc.ScriptHash)
+	if contract == nil {
+		return errors.New("no contract found")
+	}
+	if !contract.HasStorage() {
+		return errors.New("contract can't have storage")
+	}
+	return nil
+}
+
+// storageDelete deletes stored key-value pair.
+func (ic *interopContext) storageDelete(v *vm.VM) error {
+	if ic.trigger != 0x10 && ic.trigger != 0x11 {
+		return errors.New("can't delete when the trigger is not application")
+	}
+	stcInterface := v.Estack().Pop().Value()
+	stc, ok := stcInterface.(*StorageContext)
+	if !ok {
+		return fmt.Errorf("%T is not a StorageContext", stcInterface)
+	}
+	if stc.ReadOnly {
+		return errors.New("StorageContext is read only")
+	}
+	err := ic.checkStorageContext(stc)
+	if err != nil {
+		return err
+	}
+	key := v.Estack().Pop().Bytes()
+	si := getStorageItemFromStore(ic.mem, stc.ScriptHash, key)
+	if si == nil {
+		si = ic.bc.GetStorageItem(stc.ScriptHash, key)
+	}
+	if si != nil && si.IsConst {
+		return errors.New("storage item is constant")
+	}
+	return deleteStorageItemInStore(ic.mem, stc.ScriptHash, key)
+}
+
+// storageGet returns stored key-value pair.
+func (ic *interopContext) storageGet(v *vm.VM) error {
+	stcInterface := v.Estack().Pop().Value()
+	stc, ok := stcInterface.(*StorageContext)
+	if !ok {
+		return fmt.Errorf("%T is not a StorageContext", stcInterface)
+	}
+	err := ic.checkStorageContext(stc)
+	if err != nil {
+		return err
+	}
+	key := v.Estack().Pop().Bytes()
+	si := getStorageItemFromStore(ic.mem, stc.ScriptHash, key)
+	if si == nil {
+		si = ic.bc.GetStorageItem(stc.ScriptHash, key)
+	}
+	if si != nil && si.Value != nil {
+		v.Estack().PushVal(si.Value)
+	} else {
+		v.Estack().PushVal([]byte{})
+	}
+	return nil
+}
+
+// storageGetContext returns storage context (scripthash).
+func (ic *interopContext) storageGetContext(v *vm.VM) error {
+	sc := &StorageContext{
+		ScriptHash: getContextScriptHash(v, 0),
+		ReadOnly:   false,
+	}
+	v.Estack().PushVal(vm.NewInteropItem(sc))
+	return nil
+}
+
+// storageGetReadOnlyContext returns read-only context (scripthash).
+func (ic *interopContext) storageGetReadOnlyContext(v *vm.VM) error {
+	sc := &StorageContext{
+		ScriptHash: getContextScriptHash(v, 0),
+		ReadOnly:   true,
+	}
+	v.Estack().PushVal(vm.NewInteropItem(sc))
+	return nil
+}
+
+func (ic *interopContext) putWithContextAndFlags(stc *StorageContext, key []byte, value []byte, isConst bool) error {
+	if ic.trigger != 0x10 && ic.trigger != 0x11 {
+		return errors.New("can't delete when the trigger is not application")
+	}
+	if len(key) > MaxStorageKeyLen {
+		return errors.New("key is too big")
+	}
+	if stc.ReadOnly {
+		return errors.New("StorageContext is read only")
+	}
+	err := ic.checkStorageContext(stc)
+	if err != nil {
+		return err
+	}
+	si := getStorageItemFromStore(ic.mem, stc.ScriptHash, key)
+	if si == nil {
+		si = ic.bc.GetStorageItem(stc.ScriptHash, key)
+		if si == nil {
+			si = &StorageItem{}
+		}
+	}
+	if si.IsConst {
+		return errors.New("storage item exists and is read-only")
+	}
+	si.Value = value
+	si.IsConst = isConst
+	return putStorageItemIntoStore(ic.mem, stc.ScriptHash, key, si)
+}
+
+// storagePutInternal is a unified implementation of storagePut and storagePutEx.
+func (ic *interopContext) storagePutInternal(v *vm.VM, getFlag bool) error {
+	stcInterface := v.Estack().Pop().Value()
+	stc, ok := stcInterface.(*StorageContext)
+	if !ok {
+		return fmt.Errorf("%T is not a StorageContext", stcInterface)
+	}
+	key := v.Estack().Pop().Bytes()
+	value := v.Estack().Pop().Bytes()
+	var flag int
+	if getFlag {
+		flag = int(v.Estack().Pop().BigInt().Int64())
+	}
+	return ic.putWithContextAndFlags(stc, key, value, flag == 1)
+}
+
+// storagePut puts key-value pair into the storage.
+func (ic *interopContext) storagePut(v *vm.VM) error {
+	return ic.storagePutInternal(v, false)
+}
+
+// storagePutEx puts key-value pair with given flags into the storage.
+func (ic *interopContext) storagePutEx(v *vm.VM) error {
+	return ic.storagePutInternal(v, true)
+}
+
+// storageContextAsReadOnly sets given context to read-only mode.
+func (ic *interopContext) storageContextAsReadOnly(v *vm.VM) error {
+	stcInterface := v.Estack().Pop().Value()
+	stc, ok := stcInterface.(*StorageContext)
+	if !ok {
+		return fmt.Errorf("%T is not a StorageContext", stcInterface)
+	}
+	if !stc.ReadOnly {
+		stx := &StorageContext{
+			ScriptHash: stc.ScriptHash,
+			ReadOnly:   true,
+		}
+		stc = stx
+	}
+	v.Estack().PushVal(vm.NewInteropItem(stc))
+	return nil
+}
+
+// contractDestroy destroys a contract.
+func (ic *interopContext) contractDestroy(v *vm.VM) error {
+	if ic.trigger != 0x10 {
+		return errors.New("can't destroy contract when not triggered by application")
+	}
+	hash := getContextScriptHash(v, 0)
+	cs := ic.bc.GetContractState(hash)
+	if cs == nil {
+		return nil
+	}
+	err := deleteContractStateInStore(ic.mem, hash)
+	if err != nil {
+		return err
+	}
+	if cs.HasStorage() {
+		siMap, err := ic.bc.GetStorageItems(hash)
+		if err != nil {
+			return err
+		}
+		for k := range siMap {
+			_ = deleteStorageItemInStore(ic.mem, hash, []byte(k))
+		}
+	}
+	return nil
+}
+
+// contractGetStorageContext retrieves StorageContext of a contract.
+func (ic *interopContext) contractGetStorageContext(v *vm.VM) error {
+	csInterface := v.Estack().Pop().Value()
+	cs, ok := csInterface.(*ContractState)
+	if !ok {
+		return fmt.Errorf("%T is not a contract state", cs)
+	}
+	if getContractStateFromStore(ic.mem, cs.ScriptHash()) == nil {
+		return fmt.Errorf("contract was not created in this transaction")
+	}
+	stc := &StorageContext{
+		ScriptHash: cs.ScriptHash(),
+	}
+	v.Estack().PushVal(vm.NewInteropItem(stc))
+	return nil
+}

pkg/core/interops.go

@@ -0,0 +1,218 @@
+package core
+
+/*
+  Interops are designed to run under VM's execute() panic protection, so it's OK
+  for them to do things like
+          smth := v.Estack().Pop().Bytes()
+  even though technically Pop() can return a nil pointer.
+*/
+
+import (
+	"github.com/CityOfZion/neo-go/pkg/core/storage"
+	"github.com/CityOfZion/neo-go/pkg/core/transaction"
+	"github.com/CityOfZion/neo-go/pkg/vm"
+)
+
+type interopContext struct {
+	bc      Blockchainer
+	trigger byte
+	block   *Block
+	tx      *transaction.Transaction
+	mem     *storage.MemoryStore
+}
+
+func newInteropContext(trigger byte, bc Blockchainer, block *Block, tx *transaction.Transaction) *interopContext {
+	mem := storage.NewMemoryStore()
+	return &interopContext{bc, trigger, block, tx, mem}
+}
+
+// All lists are sorted, keep 'em this way, please.
+
+// getSystemInteropMap returns interop mappings for System namespace.
+func (ic *interopContext) getSystemInteropMap() map[string]vm.InteropFuncPrice {
+	return map[string]vm.InteropFuncPrice{
+		"System.Block.GetTransaction":                   {Func: ic.blockGetTransaction, Price: 1},
+		"System.Block.GetTransactionCount":              {Func: ic.blockGetTransactionCount, Price: 1},
+		"System.Block.GetTransactions":                  {Func: ic.blockGetTransactions, Price: 1},
+		"System.Blockchain.GetBlock":                    {Func: ic.bcGetBlock, Price: 200},
+		"System.Blockchain.GetContract":                 {Func: ic.bcGetContract, Price: 100},
+		"System.Blockchain.GetHeader":                   {Func: ic.bcGetHeader, Price: 100},
+		"System.Blockchain.GetHeight":                   {Func: ic.bcGetHeight, Price: 1},
+		"System.Blockchain.GetTransaction":              {Func: ic.bcGetTransaction, Price: 200},
+		"System.Blockchain.GetTransactionHeight":        {Func: ic.bcGetTransactionHeight, Price: 100},
+		"System.Contract.Destroy":                       {Func: ic.contractDestroy, Price: 1},
+		"System.Contract.GetStorageContext":             {Func: ic.contractGetStorageContext, Price: 1},
+		"System.ExecutionEngine.GetCallingScriptHash":   {Func: ic.engineGetCallingScriptHash, Price: 1},
+		"System.ExecutionEngine.GetEntryScriptHash":     {Func: ic.engineGetEntryScriptHash, Price: 1},
+		"System.ExecutionEngine.GetExecutingScriptHash": {Func: ic.engineGetExecutingScriptHash, Price: 1},
+		"System.ExecutionEngine.GetScriptContainer":     {Func: ic.engineGetScriptContainer, Price: 1},
+		"System.Header.GetHash":                         {Func: ic.headerGetHash, Price: 1},
+		"System.Header.GetIndex":                        {Func: ic.headerGetIndex, Price: 1},
+		"System.Header.GetPrevHash":                     {Func: ic.headerGetPrevHash, Price: 1},
+		"System.Header.GetTimestamp":                    {Func: ic.headerGetTimestamp, Price: 1},
+		"System.Runtime.CheckWitness":                   {Func: ic.runtimeCheckWitness, Price: 200},
+		"System.Runtime.GetTime":                        {Func: ic.runtimeGetTime, Price: 1},
+		"System.Runtime.GetTrigger":                     {Func: ic.runtimeGetTrigger, Price: 1},
+		"System.Runtime.Log":                            {Func: ic.runtimeLog, Price: 1},
+		"System.Runtime.Notify":                         {Func: ic.runtimeNotify, Price: 1},
+		"System.Runtime.Platform":                       {Func: ic.runtimePlatform, Price: 1},
+		"System.Storage.Delete":                         {Func: ic.storageDelete, Price: 100},
+		"System.Storage.Get":                            {Func: ic.storageGet, Price: 100},
+		"System.Storage.GetContext":                     {Func: ic.storageGetContext, Price: 1},
+		"System.Storage.GetReadOnlyContext":             {Func: ic.storageGetReadOnlyContext, Price: 1},
+		"System.Storage.Put":                            {Func: ic.storagePut, Price: 0}, // These don't have static price in C# code.
+		"System.Storage.PutEx":                          {Func: ic.storagePutEx, Price: 0},
+		"System.StorageContext.AsReadOnly":              {Func: ic.storageContextAsReadOnly, Price: 1},
+		"System.Transaction.GetHash":                    {Func: ic.txGetHash, Price: 1},
+		//		"System.Runtime.Deserialize":                    {Func: ic.runtimeDeserialize, Price: 1},
+		//		"System.Runtime.Serialize":                      {Func: ic.runtimeSerialize, Price: 1},
+	}
+}
+
+// getSystemInteropMap returns interop mappings for Neo and (legacy) AntShares namespaces.
+func (ic *interopContext) getNeoInteropMap() map[string]vm.InteropFuncPrice {
+	return map[string]vm.InteropFuncPrice{
+		"Neo.Account.GetBalance":              {Func: ic.accountGetBalance, Price: 1},
+		"Neo.Account.GetScriptHash":           {Func: ic.accountGetScriptHash, Price: 1},
+		"Neo.Account.GetVotes":                {Func: ic.accountGetVotes, Price: 1},
+		"Neo.Account.IsStandard":              {Func: ic.accountIsStandard, Price: 100},
+		"Neo.Asset.Create":                    {Func: ic.assetCreate, Price: 0},
+		"Neo.Asset.GetAdmin":                  {Func: ic.assetGetAdmin, Price: 1},
+		"Neo.Asset.GetAmount":                 {Func: ic.assetGetAmount, Price: 1},
+		"Neo.Asset.GetAssetId":                {Func: ic.assetGetAssetID, Price: 1},
+		"Neo.Asset.GetAssetType":              {Func: ic.assetGetAssetType, Price: 1},
+		"Neo.Asset.GetAvailable":              {Func: ic.assetGetAvailable, Price: 1},
+		"Neo.Asset.GetIssuer":                 {Func: ic.assetGetIssuer, Price: 1},
+		"Neo.Asset.GetOwner":                  {Func: ic.assetGetOwner, Price: 1},
+		"Neo.Asset.GetPrecision":              {Func: ic.assetGetPrecision, Price: 1},
+		"Neo.Asset.Renew":                     {Func: ic.assetRenew, Price: 0},
+		"Neo.Attribute.GetData":               {Func: ic.attrGetData, Price: 1},
+		"Neo.Attribute.GetUsage":              {Func: ic.attrGetUsage, Price: 1},
+		"Neo.Block.GetTransaction":            {Func: ic.blockGetTransaction, Price: 1},
+		"Neo.Block.GetTransactionCount":       {Func: ic.blockGetTransactionCount, Price: 1},
+		"Neo.Block.GetTransactions":           {Func: ic.blockGetTransactions, Price: 1},
+		"Neo.Blockchain.GetAccount":           {Func: ic.bcGetAccount, Price: 100},
+		"Neo.Blockchain.GetAsset":             {Func: ic.bcGetAsset, Price: 100},
+		"Neo.Blockchain.GetBlock":             {Func: ic.bcGetBlock, Price: 200},
+		"Neo.Blockchain.GetContract":          {Func: ic.bcGetContract, Price: 100},
+		"Neo.Blockchain.GetHeader":            {Func: ic.bcGetHeader, Price: 100},
+		"Neo.Blockchain.GetHeight":            {Func: ic.bcGetHeight, Price: 1},
+		"Neo.Blockchain.GetTransaction":       {Func: ic.bcGetTransaction, Price: 100},
+		"Neo.Blockchain.GetTransactionHeight": {Func: ic.bcGetTransactionHeight, Price: 100},
+		"Neo.Contract.Create":                 {Func: ic.contractCreate, Price: 0},
+		"Neo.Contract.Destroy":                {Func: ic.contractDestroy, Price: 1},
+		"Neo.Contract.GetScript":              {Func: ic.contractGetScript, Price: 1},
+		"Neo.Contract.GetStorageContext":      {Func: ic.contractGetStorageContext, Price: 1},
+		"Neo.Contract.IsPayable":              {Func: ic.contractIsPayable, Price: 1},
+		"Neo.Contract.Migrate":                {Func: ic.contractMigrate, Price: 0},
+		"Neo.Header.GetConsensusData":         {Func: ic.headerGetConsensusData, Price: 1},
+		"Neo.Header.GetHash":                  {Func: ic.headerGetHash, Price: 1},
+		"Neo.Header.GetIndex":                 {Func: ic.headerGetIndex, Price: 1},
+		"Neo.Header.GetMerkleRoot":            {Func: ic.headerGetMerkleRoot, Price: 1},
+		"Neo.Header.GetNextConsensus":         {Func: ic.headerGetNextConsensus, Price: 1},
+		"Neo.Header.GetPrevHash":              {Func: ic.headerGetPrevHash, Price: 1},
+		"Neo.Header.GetTimestamp":             {Func: ic.headerGetTimestamp, Price: 1},
+		"Neo.Header.GetVersion":               {Func: ic.headerGetVersion, Price: 1},
+		"Neo.Input.GetHash":                   {Func: ic.inputGetHash, Price: 1},
+		"Neo.Input.GetIndex":                  {Func: ic.inputGetIndex, Price: 1},
+		"Neo.Output.GetAssetId":               {Func: ic.outputGetAssetID, Price: 1},
+		"Neo.Output.GetScriptHash":            {Func: ic.outputGetScriptHash, Price: 1},
+		"Neo.Output.GetValue":                 {Func: ic.outputGetValue, Price: 1},
+		"Neo.Runtime.CheckWitness":            {Func: ic.runtimeCheckWitness, Price: 200},
+		"Neo.Runtime.GetTime":                 {Func: ic.runtimeGetTime, Price: 1},
+		"Neo.Runtime.GetTrigger":              {Func: ic.runtimeGetTrigger, Price: 1},
+		"Neo.Runtime.Log":                     {Func: ic.runtimeLog, Price: 1},
+		"Neo.Runtime.Notify":                  {Func: ic.runtimeNotify, Price: 1},
+		"Neo.Storage.Delete":                  {Func: ic.storageDelete, Price: 100},
+		"Neo.Storage.Get":                     {Func: ic.storageGet, Price: 100},
+		"Neo.Storage.GetContext":              {Func: ic.storageGetContext, Price: 1},
+		"Neo.Storage.GetReadOnlyContext":      {Func: ic.storageGetReadOnlyContext, Price: 1},
+		"Neo.Storage.Put":                     {Func: ic.storagePut, Price: 0},
+		"Neo.StorageContext.AsReadOnly":       {Func: ic.storageContextAsReadOnly, Price: 1},
+		"Neo.Transaction.GetAttributes":       {Func: ic.txGetAttributes, Price: 1},
+		"Neo.Transaction.GetHash":             {Func: ic.txGetHash, Price: 1},
+		"Neo.Transaction.GetInputs":           {Func: ic.txGetInputs, Price: 1},
+		"Neo.Transaction.GetOutputs":          {Func: ic.txGetOutputs, Price: 1},
+		"Neo.Transaction.GetReferences":       {Func: ic.txGetReferences, Price: 200},
+		"Neo.Transaction.GetType":             {Func: ic.txGetType, Price: 1},
+		"Neo.Transaction.GetUnspentCoins":     {Func: ic.txGetUnspentCoins, Price: 200},
+		"Neo.Transaction.GetWitnesses":        {Func: ic.txGetWitnesses, Price: 200},
+		//		"Neo.Blockchain.GetValidators":        {Func: ic.bcGetValidators, Price: 200},
+		//		"Neo.Enumerator.Concat": {Func: ic.enumeratorConcat, Price: 1},
+		//		"Neo.Enumerator.Create": {Func: ic.enumeratorCreate, Price: 1},
+		//		"Neo.Enumerator.Next": {Func: ic.enumeratorNext, Price: 1},
+		//		"Neo.Enumerator.Value": {Func: ic.enumeratorValue, Price: 1},
+		//		"Neo.InvocationTransaction.GetScript": {ic.invocationTx_GetScript, 1},
+		//		"Neo.Iterator.Concat": {Func: ic.iteratorConcat, Price: 1},
+		//		"Neo.Iterator.Create": {Func: ic.iteratorCreate, Price: 1},
+		//		"Neo.Iterator.Key": {Func: ic.iteratorKey, Price: 1},
+		//		"Neo.Iterator.Keys": {Func: ic.iteratorKeys, Price: 1},
+		//		"Neo.Iterator.Values": {Func: ic.iteratorValues, Price: 1},
+		//		"Neo.Runtime.Deserialize":  {Func: ic.runtimeDeserialize, Price: 1},
+		//		"Neo.Runtime.Serialize":    {Func: ic.runtimeSerialize, Price: 1},
+		//		"Neo.Storage.Find":                {Func: ic.storageFind, Price: 1},
+		//		"Neo.Witness.GetVerificationScript": {Func: ic.witnessGetVerificationScript, Price: 100},
+
+		// Aliases.
+		//		"Neo.Iterator.Next": {Func: ic.enumeratorNext, Price: 1},
+		//		"Neo.Iterator.Value": {Func: ic.enumeratorValue, Price: 1},
+
+		// Old compatibility APIs.
+		"AntShares.Account.GetBalance":         {Func: ic.accountGetBalance, Price: 1},
+		"AntShares.Account.GetScriptHash":      {Func: ic.accountGetScriptHash, Price: 1},
+		"AntShares.Account.GetVotes":           {Func: ic.accountGetVotes, Price: 1},
+		"AntShares.Asset.Create":               {Func: ic.assetCreate, Price: 0},
+		"AntShares.Asset.GetAdmin":             {Func: ic.assetGetAdmin, Price: 1},
+		"AntShares.Asset.GetAmount":            {Func: ic.assetGetAmount, Price: 1},
+		"AntShares.Asset.GetAssetId":           {Func: ic.assetGetAssetID, Price: 1},
+		"AntShares.Asset.GetAssetType":         {Func: ic.assetGetAssetType, Price: 1},
+		"AntShares.Asset.GetAvailable":         {Func: ic.assetGetAvailable, Price: 1},
+		"AntShares.Asset.GetIssuer":            {Func: ic.assetGetIssuer, Price: 1},
+		"AntShares.Asset.GetOwner":             {Func: ic.assetGetOwner, Price: 1},
+		"AntShares.Asset.GetPrecision":         {Func: ic.assetGetPrecision, Price: 1},
+		"AntShares.Asset.Renew":                {Func: ic.assetRenew, Price: 0},
+		"AntShares.Attribute.GetData":          {Func: ic.attrGetData, Price: 1},
+		"AntShares.Attribute.GetUsage":         {Func: ic.attrGetUsage, Price: 1},
+		"AntShares.Block.GetTransaction":       {Func: ic.blockGetTransaction, Price: 1},
+		"AntShares.Block.GetTransactionCount":  {Func: ic.blockGetTransactionCount, Price: 1},
+		"AntShares.Block.GetTransactions":      {Func: ic.blockGetTransactions, Price: 1},
+		"AntShares.Blockchain.GetAccount":      {Func: ic.bcGetAccount, Price: 100},
+		"AntShares.Blockchain.GetAsset":        {Func: ic.bcGetAsset, Price: 100},
+		"AntShares.Blockchain.GetBlock":        {Func: ic.bcGetBlock, Price: 200},
+		"AntShares.Blockchain.GetContract":     {Func: ic.bcGetContract, Price: 100},
+		"AntShares.Blockchain.GetHeader":       {Func: ic.bcGetHeader, Price: 100},
+		"AntShares.Blockchain.GetHeight":       {Func: ic.bcGetHeight, Price: 1},
+		"AntShares.Blockchain.GetTransaction":  {Func: ic.bcGetTransaction, Price: 100},
+		"AntShares.Contract.Create":            {Func: ic.contractCreate, Price: 0},
+		"AntShares.Contract.Destroy":           {Func: ic.contractDestroy, Price: 1},
+		"AntShares.Contract.GetScript":         {Func: ic.contractGetScript, Price: 1},
+		"AntShares.Contract.GetStorageContext": {Func: ic.contractGetStorageContext, Price: 1},
+		"AntShares.Contract.Migrate":           {Func: ic.contractMigrate, Price: 0},
+		"AntShares.Header.GetConsensusData":    {Func: ic.headerGetConsensusData, Price: 1},
+		"AntShares.Header.GetHash":             {Func: ic.headerGetHash, Price: 1},
+		"AntShares.Header.GetMerkleRoot":       {Func: ic.headerGetMerkleRoot, Price: 1},
+		"AntShares.Header.GetNextConsensus":    {Func: ic.headerGetNextConsensus, Price: 1},
+		"AntShares.Header.GetPrevHash":         {Func: ic.headerGetPrevHash, Price: 1},
+		"AntShares.Header.GetTimestamp":        {Func: ic.headerGetTimestamp, Price: 1},
+		"AntShares.Header.GetVersion":          {Func: ic.headerGetVersion, Price: 1},
+		"AntShares.Input.GetHash":              {Func: ic.inputGetHash, Price: 1},
+		"AntShares.Input.GetIndex":             {Func: ic.inputGetIndex, Price: 1},
+		"AntShares.Output.GetAssetId":          {Func: ic.outputGetAssetID, Price: 1},
+		"AntShares.Output.GetScriptHash":       {Func: ic.outputGetScriptHash, Price: 1},
+		"AntShares.Output.GetValue":            {Func: ic.outputGetValue, Price: 1},
+		"AntShares.Runtime.CheckWitness":       {Func: ic.runtimeCheckWitness, Price: 200},
+		"AntShares.Runtime.Log":                {Func: ic.runtimeLog, Price: 1},
+		"AntShares.Runtime.Notify":             {Func: ic.runtimeNotify, Price: 1},
+		"AntShares.Storage.Delete":             {Func: ic.storageDelete, Price: 100},
+		"AntShares.Storage.Get":                {Func: ic.storageGet, Price: 100},
+		"AntShares.Storage.GetContext":         {Func: ic.storageGetContext, Price: 1},
+		"AntShares.Storage.Put":                {Func: ic.storagePut, Price: 0},
+		"AntShares.Transaction.GetAttributes":  {Func: ic.txGetAttributes, Price: 1},
+		"AntShares.Transaction.GetHash":        {Func: ic.txGetHash, Price: 1},
+		"AntShares.Transaction.GetInputs":      {Func: ic.txGetInputs, Price: 1},
+		"AntShares.Transaction.GetOutputs":     {Func: ic.txGetOutputs, Price: 1},
+		"AntShares.Transaction.GetReferences":  {Func: ic.txGetReferences, Price: 200},
+		"AntShares.Transaction.GetType":        {Func: ic.txGetType, Price: 1},
+		//		"AntShares.Blockchain.GetValidators": {Func: ic.bcGetValidators, Price: 200},
+	}
+}

pkg/core/storage/boltdb_store.go

@@ -71,12 +71,26 @@ func (s *BoltDBStore) Get(key []byte) (val []byte, err error) {
 	return
 }
 
+// Delete implements the Store interface.
+func (s *BoltDBStore) Delete(key []byte) error {
+	return s.db.Update(func(tx *bbolt.Tx) error {
+		b := tx.Bucket(Bucket)
+		return b.Delete(key)
+	})
+}
+
 // PutBatch implements the Store interface.
 func (s *BoltDBStore) PutBatch(batch Batch) error {
 	return s.db.Batch(func(tx *bbolt.Tx) error {
 		b := tx.Bucket(Bucket)
-		for k, v := range batch.(*MemoryBatch).m {
-			err := b.Put(*k, v)
+		for k, v := range batch.(*MemoryBatch).mem {
+			err := b.Put([]byte(k), v)
+			if err != nil {
+				return err
+			}
+		}
+		for k := range batch.(*MemoryBatch).del {
+			err := b.Delete([]byte(k))
 			if err != nil {
 				return err
 			}

pkg/core/storage/boltdb_store_test.go

@@ -3,83 +3,12 @@ package storage
 import (
 	"io/ioutil"
 	"os"
-	"reflect"
 	"testing"
 
-	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
 
-func TestBoltDBBatch(t *testing.T) {
-	boltDB := BoltDBStore{}
-	want := &MemoryBatch{m: map[*[]byte][]byte{}}
-	if got := boltDB.Batch(); !reflect.DeepEqual(got, want) {
-		t.Errorf("BoltDB Batch() = %v, want %v", got, want)
-	}
-}
-
-func TestBoltDBBatch_Len(t *testing.T) {
-	batch := &MemoryBatch{m: map[*[]byte][]byte{}}
-	want := len(map[*[]byte][]byte{})
-	assert.Equal(t, want, batch.Len())
-}
-
-func TestBoltDBBatch_PutBatchAndGet(t *testing.T) {
-	key := []byte("foo")
-	keycopy := make([]byte, len(key))
-	copy(keycopy, key)
-	value := []byte("bar")
-	valuecopy := make([]byte, len(value))
-	copy(valuecopy, value)
-	boltDBStore := openStore(t)
-	batch := boltDBStore.Batch()
-
-	batch.Put(keycopy, valuecopy)
-	copy(valuecopy, key)
-	copy(keycopy, value)
-	errPut := boltDBStore.PutBatch(batch)
-	assert.Nil(t, errPut, "Error while PutBatch")
-
-	result, err := boltDBStore.Get(key)
-	assert.Nil(t, err)
-	assert.Equal(t, value, result)
-
-	require.NoError(t, boltDBStore.Close())
-}
-
-func TestBoltDBBatch_PutAndGet(t *testing.T) {
-	key := []byte("foo")
-	value := []byte("bar")
-
-	boltDBStore := openStore(t)
-
-	errPut := boltDBStore.Put(key, value)
-	assert.Nil(t, errPut, "Error while Put")
-
-	result, err := boltDBStore.Get(key)
-	assert.Nil(t, err)
-	assert.Equal(t, value, result)
-
-	require.NoError(t, boltDBStore.Close())
-}
-
-func TestBoltDBStore_Seek(t *testing.T) {
-	key := []byte("foo")
-	value := []byte("bar")
-
-	boltDBStore := openStore(t)
-
-	errPut := boltDBStore.Put(key, value)
-	assert.Nil(t, errPut, "Error while Put")
-
-	boltDBStore.Seek(key, func(k, v []byte) {
-		assert.Equal(t, value, v)
-	})
-
-	require.NoError(t, boltDBStore.Close())
-}
-
-func openStore(t *testing.T) *BoltDBStore {
+func newBoltStoreForTesting(t *testing.T) Store {
 	testFileName := "test_bolt_db"
 	file, err := ioutil.TempFile("", testFileName)
 	defer func() {

pkg/core/storage/leveldb_store.go

@@ -48,6 +48,11 @@ func (s *LevelDBStore) Get(key []byte) ([]byte, error) {
 	return value, err
 }
 
+// Delete implements the Store interface.
+func (s *LevelDBStore) Delete(key []byte) error {
+	return s.db.Delete(key, nil)
+}
+
 // PutBatch implements the Store interface.
 func (s *LevelDBStore) PutBatch(batch Batch) error {
 	lvldbBatch := batch.(*leveldb.Batch)

pkg/core/storage/leveldb_store_test.go

@@ -1 +1,41 @@
 package storage
+
+import (
+	"io/ioutil"
+	"os"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+type tempLevelDB struct {
+	LevelDBStore
+	dir string
+}
+
+func (tldb *tempLevelDB) Close() error {
+	err := tldb.LevelDBStore.Close()
+	// Make test fail if failed to cleanup, even though technically it's
+	// not a LevelDBStore problem.
+	osErr := os.RemoveAll(tldb.dir)
+	if osErr != nil {
+		return osErr
+	}
+	return err
+}
+
+func newLevelDBForTesting(t *testing.T) Store {
+	ldbDir, err := ioutil.TempDir(os.TempDir(), "testleveldb")
+	require.Nil(t, err, "failed to setup temporary directory")
+
+	dbConfig := DBConfiguration{
+		Type: "leveldb",
+		LevelDBOptions: LevelDBOptions{
+			DataDirectoryPath: ldbDir,
+		},
+	}
+	newLevelStore, err := NewLevelDBStore(dbConfig.LevelDBOptions)
+	require.Nil(t, err, "NewLevelDBStore error")
+	tldb := &tempLevelDB{LevelDBStore: *newLevelStore, dir: ldbDir}
+	return tldb
+}

pkg/core/storage/memory_store.go

@@ -1,7 +1,6 @@
 package storage
 
 import (
-	"encoding/hex"
 	"strings"
 	"sync"
 )
@@ -11,31 +10,30 @@ import (
 type MemoryStore struct {
 	mut sync.RWMutex
 	mem map[string][]byte
+	// A map, not a slice, to avoid duplicates.
+	del map[string]bool
 }
 
 // MemoryBatch a in-memory batch compatible with MemoryStore.
 type MemoryBatch struct {
-	m map[*[]byte][]byte
+	MemoryStore
 }
 
 // Put implements the Batch interface.
 func (b *MemoryBatch) Put(k, v []byte) {
-	vcopy := make([]byte, len(v))
-	copy(vcopy, v)
-	kcopy := make([]byte, len(k))
-	copy(kcopy, k)
-	b.m[&kcopy] = vcopy
+	_ = b.MemoryStore.Put(k, v)
 }
 
-// Len implements the Batch interface.
-func (b *MemoryBatch) Len() int {
-	return len(b.m)
+// Delete implements Batch interface.
+func (b *MemoryBatch) Delete(k []byte) {
+	_ = b.MemoryStore.Delete(k)
 }
 
 // NewMemoryStore creates a new MemoryStore object.
 func NewMemoryStore() *MemoryStore {
 	return &MemoryStore{
 		mem: make(map[string][]byte),
+		del: make(map[string]bool),
 	}
 }
 
@@ -43,16 +41,42 @@ func NewMemoryStore() *MemoryStore {
 func (s *MemoryStore) Get(key []byte) ([]byte, error) {
 	s.mut.RLock()
 	defer s.mut.RUnlock()
-	if val, ok := s.mem[makeKey(key)]; ok {
+	if val, ok := s.mem[string(key)]; ok {
 		return val, nil
 	}
 	return nil, ErrKeyNotFound
 }
 
+// put puts a key-value pair into the store, it's supposed to be called
+// with mutex locked.
+func (s *MemoryStore) put(key string, value []byte) {
+	s.mem[key] = value
+	delete(s.del, key)
+}
+
 // Put implements the Store interface. Never returns an error.
 func (s *MemoryStore) Put(key, value []byte) error {
+	newKey := string(key)
+	vcopy := make([]byte, len(value))
+	copy(vcopy, value)
 	s.mut.Lock()
-	s.mem[makeKey(key)] = value
+	s.put(newKey, vcopy)
+	s.mut.Unlock()
+	return nil
+}
+
+// drop deletes a key-valu pair from the store, it's supposed to be called
+// with mutex locked.
+func (s *MemoryStore) drop(key string) {
+	s.del[key] = true
+	delete(s.mem, key)
+}
+
+// Delete implements Store interface. Never returns an error.
+func (s *MemoryStore) Delete(key []byte) error {
+	newKey := string(key)
+	s.mut.Lock()
+	s.drop(newKey)
 	s.mut.Unlock()
 	return nil
 }
@@ -60,8 +84,13 @@ func (s *MemoryStore) Put(key, value []byte) error {
 // PutBatch implements the Store interface. Never returns an error.
 func (s *MemoryStore) PutBatch(batch Batch) error {
 	b := batch.(*MemoryBatch)
-	for k, v := range b.m {
-		_ = s.Put(*k, v)
+	s.mut.Lock()
+	defer s.mut.Unlock()
+	for k := range b.del {
+		s.drop(k)
+	}
+	for k, v := range b.mem {
+		s.put(k, v)
 	}
 	return nil
 }
@@ -69,9 +98,8 @@ func (s *MemoryStore) PutBatch(batch Batch) error {
 // Seek implements the Store interface.
 func (s *MemoryStore) Seek(key []byte, f func(k, v []byte)) {
 	for k, v := range s.mem {
-		if strings.Contains(k, hex.EncodeToString(key)) {
-			decodeString, _ := hex.DecodeString(k)
-			f(decodeString, v)
+		if strings.HasPrefix(k, string(key)) {
+			f([]byte(k), v)
 		}
 	}
 }
@@ -83,9 +111,7 @@ func (s *MemoryStore) Batch() Batch {
 
 // newMemoryBatch returns new memory batch.
 func newMemoryBatch() *MemoryBatch {
-	return &MemoryBatch{
-		m: make(map[*[]byte][]byte),
-	}
+	return &MemoryBatch{MemoryStore: *NewMemoryStore()}
 }
 
 // Persist flushes all the MemoryStore contents into the (supposedly) persistent
@@ -94,18 +120,22 @@ func (s *MemoryStore) Persist(ps Store) (int, error) {
 	s.mut.Lock()
 	defer s.mut.Unlock()
 	batch := ps.Batch()
-	keys := 0
+	keys, dkeys := 0, 0
 	for k, v := range s.mem {
-		kb, _ := hex.DecodeString(k)
-		batch.Put(kb, v)
+		batch.Put([]byte(k), v)
 		keys++
 	}
+	for k := range s.del {
+		batch.Delete([]byte(k))
+		dkeys++
+	}
 	var err error
-	if keys != 0 {
+	if keys != 0 || dkeys != 0 {
 		err = ps.PutBatch(batch)
 	}
 	if err == nil {
 		s.mem = make(map[string][]byte)
+		s.del = make(map[string]bool)
 	}
 	return keys, err
 }
@@ -114,11 +144,8 @@ func (s *MemoryStore) Persist(ps Store) (int, error) {
 // error.
 func (s *MemoryStore) Close() error {
 	s.mut.Lock()
+	s.del = nil
 	s.mem = nil
 	s.mut.Unlock()
 	return nil
 }
-
-func makeKey(k []byte) string {
-	return hex.EncodeToString(k)
-}

pkg/core/storage/memory_store_test.go

@@ -4,78 +4,8 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
 )
 
-func TestGetPut(t *testing.T) {
-	var (
-		s     = NewMemoryStore()
-		key   = []byte("sparse")
-		value = []byte("rocks")
-	)
-
-	if err := s.Put(key, value); err != nil {
-		t.Fatal(err)
-	}
-
-	newVal, err := s.Get(key)
-	if err != nil {
-		t.Fatal(err)
-	}
-	assert.Equal(t, value, newVal)
-	require.NoError(t, s.Close())
-}
-
-func TestKeyNotExist(t *testing.T) {
-	var (
-		s   = NewMemoryStore()
-		key = []byte("sparse")
-	)
-
-	_, err := s.Get(key)
-	assert.NotNil(t, err)
-	assert.Equal(t, err.Error(), "key not found")
-	require.NoError(t, s.Close())
-}
-
-func TestPutBatch(t *testing.T) {
-	var (
-		s     = NewMemoryStore()
-		key   = []byte("sparse")
-		value = []byte("rocks")
-		batch = s.Batch()
-	)
-
-	batch.Put(key, value)
-
-	if err := s.PutBatch(batch); err != nil {
-		t.Fatal(err)
-	}
-
-	newVal, err := s.Get(key)
-	if err != nil {
-		t.Fatal(err)
-	}
-	assert.Equal(t, value, newVal)
-	require.NoError(t, s.Close())
-}
-
-func TestMemoryStore_Seek(t *testing.T) {
-	var (
-		s     = NewMemoryStore()
-		key   = []byte("sparse")
-		value = []byte("rocks")
-	)
-
-	if err := s.Put(key, value); err != nil {
-		t.Fatal(err)
-	}
-
-	s.Seek(key, func(k, v []byte) {
-		assert.Equal(t, value, v)
-	})
-}
-
 func TestMemoryStorePersist(t *testing.T) {
 	// temporary Store
 	ts := NewMemoryStore()
@@ -125,4 +55,20 @@ func TestMemoryStorePersist(t *testing.T) {
 	c, err = ts.Persist(ps)
 	assert.Equal(t, nil, err)
 	assert.Equal(t, 0, c)
+	// test persisting deletions
+	err = ts.Delete([]byte("key"))
+	assert.Equal(t, nil, err)
+	c, err = ts.Persist(ps)
+	assert.Equal(t, nil, err)
+	assert.Equal(t, 0, c)
+	v, err = ps.Get([]byte("key"))
+	assert.Equal(t, ErrKeyNotFound, err)
+	assert.Equal(t, []byte(nil), v)
+	v, err = ps.Get([]byte("key2"))
+	assert.Equal(t, nil, err)
+	assert.Equal(t, []byte("value2"), v)
+}
+
+func newMemoryStoreForTesting(t *testing.T) Store {
+	return NewMemoryStore()
 }

pkg/core/storage/redis_store.go

@@ -48,6 +48,12 @@ func (s *RedisStore) Get(k []byte) ([]byte, error) {
 	return []byte(val), nil
 }
 
+// Delete implements the Store interface.
+func (s *RedisStore) Delete(k []byte) error {
+	s.client.Del(string(k))
+	return nil
+}
+
 // Put implements the Store interface.
 func (s *RedisStore) Put(k, v []byte) error {
 	s.client.Set(string(k), string(v), 0)
@@ -57,8 +63,11 @@ func (s *RedisStore) Put(k, v []byte) error {
 // PutBatch implements the Store interface.
 func (s *RedisStore) PutBatch(b Batch) error {
 	pipe := s.client.Pipeline()
-	for k, v := range b.(*MemoryBatch).m {
-		pipe.Set(string(*k), v, 0)
+	for k, v := range b.(*MemoryBatch).mem {
+		pipe.Set(k, v, 0)
+	}
+	for k := range b.(*MemoryBatch).del {
+		pipe.Del(k)
 	}
 	_, err := pipe.Exec()
 	return err

pkg/core/storage/redis_store_test.go

@@ -4,109 +4,18 @@ import (
 	"testing"
 
 	"github.com/alicebob/miniredis"
-	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
 
-func TestNewRedisStore(t *testing.T) {
-	redisMock, redisStore := prepareRedisMock(t)
-	key := []byte("testKey")
-	value := []byte("testValue")
-	err := redisStore.Put(key, value)
-	assert.Nil(t, err, "NewRedisStore Put error")
-
-	result, err := redisStore.Get(key)
-	assert.Nil(t, err, "NewRedisStore Get error")
-
-	assert.Equal(t, value, result)
-	require.NoError(t, redisStore.Close())
-	redisMock.Close()
-}
-
-func TestRedisBatch_Len(t *testing.T) {
-	want := len(map[string]string{})
-	b := &MemoryBatch{
-		m: map[*[]byte][]byte{},
-	}
-	assert.Equal(t, len(b.m), want)
-}
-
-func TestRedisStore_GetAndPut(t *testing.T) {
-	prepareRedisMock(t)
-	type args struct {
-		k       []byte
-		v       []byte
-		kToLook []byte
-	}
-	tests := []struct {
-		name    string
-		args    args
-		want    []byte
-		wantErr bool
-	}{
-		{"TestRedisStore_Get_Strings",
-			args{
-				k:       []byte("foo"),
-				v:       []byte("bar"),
-				kToLook: []byte("foo"),
-			},
-			[]byte("bar"),
-			false,
-		},
-		{"TestRedisStore_Get_Negative_Strings",
-			args{
-				k:       []byte("foo"),
-				v:       []byte("bar"),
-				kToLook: []byte("wrong"),
-			},
-			[]byte(nil),
-			true,
-		},
-	}
-	redisMock, redisStore := prepareRedisMock(t)
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			err := redisStore.Put(tt.args.k, tt.args.v)
-			assert.Nil(t, err, "Got error while Put operation processing")
-			got, err := redisStore.Get(tt.args.kToLook)
-			if (err != nil) != tt.wantErr {
-				t.Errorf("Get() error = %v, wantErr %v", err, tt.wantErr)
-				return
-			}
-			assert.Equal(t, tt.want, got)
-			redisMock.FlushDB()
-		})
-	}
-	require.NoError(t, redisStore.Close())
-	redisMock.Close()
-}
-
-func TestRedisStore_PutBatch(t *testing.T) {
-	batch := &MemoryBatch{m: map[*[]byte][]byte{&[]byte{'f', 'o', 'o', '1'}: []byte("bar1")}}
-	mock, redisStore := prepareRedisMock(t)
-	err := redisStore.PutBatch(batch)
-	assert.Nil(t, err, "Error while PutBatch")
-	result, err := redisStore.Get([]byte("foo1"))
-	assert.Nil(t, err)
-	assert.Equal(t, []byte("bar1"), result)
-	require.NoError(t, redisStore.Close())
-	mock.Close()
-}
-
-func TestRedisStore_Seek(t *testing.T) {
-	mock, redisStore := prepareRedisMock(t)
-	redisStore.Seek([]byte("foo"), func(k, v []byte) {
-		assert.Equal(t, []byte("bar"), v)
-	})
-	require.NoError(t, redisStore.Close())
-	mock.Close()
+type mockedRedisStore struct {
+	RedisStore
+	mini *miniredis.Miniredis
 }
 
 func prepareRedisMock(t *testing.T) (*miniredis.Miniredis, *RedisStore) {
 	miniRedis, err := miniredis.Run()
-	if err != nil {
-		t.Errorf("MiniRedis mock creation error = %v", err)
-	}
+	require.Nil(t, err, "MiniRedis mock creation error")
+
 	_ = miniRedis.Set("foo", "bar")
 
 	dbConfig := DBConfiguration{
@@ -118,9 +27,18 @@ func prepareRedisMock(t *testing.T) (*miniredis.Miniredis, *RedisStore) {
 		},
 	}
 	newRedisStore, err := NewRedisStore(dbConfig.RedisDBOptions)
-	if err != nil {
-		t.Errorf("NewRedisStore() error = %v", err)
-		return nil, nil
-	}
+	require.Nil(t, err, "NewRedisStore() error")
 	return miniRedis, newRedisStore
 }
+
+func (mrs *mockedRedisStore) Close() error {
+	err := mrs.RedisStore.Close()
+	mrs.mini.Close()
+	return err
+}
+
+func newRedisStoreForTesting(t *testing.T) Store {
+	mock, rs := prepareRedisMock(t)
+	mrs := &mockedRedisStore{RedisStore: *rs, mini: mock}
+	return mrs
+}

pkg/core/storage/store.go

@@ -32,6 +32,7 @@ type (
 	// information.
 	Store interface {
 		Batch() Batch
+		Delete(k []byte) error
 		Get([]byte) ([]byte, error)
 		Put(k, v []byte) error
 		PutBatch(Batch) error
@@ -43,8 +44,8 @@ type (
 	// Each Store implementation is responsible of casting a Batch
 	// to its appropriate type.
 	Batch interface {
+		Delete(k []byte)
 		Put(k, v []byte)
-		Len() int
 	}
 
 	// KeyPrefix is a constant byte added as a prefix for each key

pkg/core/storage/storeandbatch_test.go

@@ -0,0 +1,239 @@
+package storage
+
+import (
+	"reflect"
+	"runtime"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+type dbSetup struct {
+	name   string
+	create func(*testing.T) Store
+}
+
+type dbTestFunction func(*testing.T, Store)
+
+func testStoreClose(t *testing.T, s Store) {
+	require.NoError(t, s.Close())
+}
+
+func testStorePutAndGet(t *testing.T, s Store) {
+	key := []byte("foo")
+	value := []byte("bar")
+
+	require.NoError(t, s.Put(key, value))
+
+	result, err := s.Get(key)
+	assert.Nil(t, err)
+	require.Equal(t, value, result)
+
+	require.NoError(t, s.Close())
+}
+
+func testStoreGetNonExistent(t *testing.T, s Store) {
+	key := []byte("sparse")
+
+	_, err := s.Get(key)
+	assert.Equal(t, err, ErrKeyNotFound)
+	require.NoError(t, s.Close())
+}
+
+func testStorePutBatch(t *testing.T, s Store) {
+	var (
+		key   = []byte("foo")
+		value = []byte("bar")
+		batch = s.Batch()
+	)
+	// Test that key and value are copied when batching.
+	keycopy := make([]byte, len(key))
+	copy(keycopy, key)
+	valuecopy := make([]byte, len(value))
+	copy(valuecopy, value)
+
+	batch.Put(keycopy, valuecopy)
+	copy(valuecopy, key)
+	copy(keycopy, value)
+
+	require.NoError(t, s.PutBatch(batch))
+	newVal, err := s.Get(key)
+	assert.Nil(t, err)
+	require.Equal(t, value, newVal)
+	assert.Equal(t, value, newVal)
+	require.NoError(t, s.Close())
+}
+
+func testStoreSeek(t *testing.T, s Store) {
+	type kvSeen struct {
+		key  []byte
+		val  []byte
+		seen bool
+	}
+	var (
+		// Given this prefix...
+		goodprefix = []byte{'f'}
+		// these pairs should be found...
+		goodkvs = []kvSeen{
+			{[]byte("foo"), []byte("bar"), false},
+			{[]byte("faa"), []byte("bra"), false},
+			{[]byte("foox"), []byte("barx"), false},
+		}
+		// and these should be not.
+		badkvs = []kvSeen{
+			{[]byte("doo"), []byte("pow"), false},
+			{[]byte("mew"), []byte("qaz"), false},
+		}
+	)
+
+	for _, v := range goodkvs {
+		require.NoError(t, s.Put(v.key, v.val))
+	}
+	for _, v := range badkvs {
+		require.NoError(t, s.Put(v.key, v.val))
+	}
+
+	numFound := 0
+	s.Seek(goodprefix, func(k, v []byte) {
+		for i := 0; i < len(goodkvs); i++ {
+			if string(k) == string(goodkvs[i].key) {
+				assert.Equal(t, string(goodkvs[i].val), string(v))
+				goodkvs[i].seen = true
+			}
+		}
+		for i := 0; i < len(badkvs); i++ {
+			if string(k) == string(badkvs[i].key) {
+				badkvs[i].seen = true
+			}
+		}
+		numFound++
+	})
+	assert.Equal(t, len(goodkvs), numFound)
+	for i := 0; i < len(goodkvs); i++ {
+		assert.Equal(t, true, goodkvs[i].seen)
+	}
+	for i := 0; i < len(badkvs); i++ {
+		assert.Equal(t, false, badkvs[i].seen)
+	}
+	require.NoError(t, s.Close())
+}
+
+func testStoreDeleteNonExistent(t *testing.T, s Store) {
+	key := []byte("sparse")
+
+	assert.NoError(t, s.Delete(key))
+	require.NoError(t, s.Close())
+}
+
+func testStorePutAndDelete(t *testing.T, s Store) {
+	key := []byte("foo")
+	value := []byte("bar")
+
+	require.NoError(t, s.Put(key, value))
+
+	err := s.Delete(key)
+	assert.Nil(t, err)
+
+	_, err = s.Get(key)
+	assert.NotNil(t, err)
+	assert.Equal(t, err, ErrKeyNotFound)
+
+	// Double delete.
+	err = s.Delete(key)
+	assert.Nil(t, err)
+
+	require.NoError(t, s.Close())
+}
+
+func testStorePutBatchWithDelete(t *testing.T, s Store) {
+	var (
+		toBeStored = map[string][]byte{
+			"foo": []byte("bar"),
+			"bar": []byte("baz"),
+		}
+		deletedInBatch = map[string][]byte{
+			"edc": []byte("rfv"),
+			"tgb": []byte("yhn"),
+		}
+		readdedToBatch = map[string][]byte{
+			"yhn": []byte("ujm"),
+		}
+		toBeDeleted = map[string][]byte{
+			"qaz": []byte("wsx"),
+			"qwe": []byte("123"),
+		}
+		toStay = map[string][]byte{
+			"key": []byte("val"),
+			"faa": []byte("bra"),
+		}
+	)
+	for k, v := range toBeDeleted {
+		require.NoError(t, s.Put([]byte(k), v))
+	}
+	for k, v := range toStay {
+		require.NoError(t, s.Put([]byte(k), v))
+	}
+	batch := s.Batch()
+	for k, v := range toBeStored {
+		batch.Put([]byte(k), v)
+	}
+	for k := range toBeDeleted {
+		batch.Delete([]byte(k))
+	}
+	for k, v := range readdedToBatch {
+		batch.Put([]byte(k), v)
+	}
+	for k, v := range deletedInBatch {
+		batch.Put([]byte(k), v)
+	}
+	for k := range deletedInBatch {
+		batch.Delete([]byte(k))
+	}
+	for k := range readdedToBatch {
+		batch.Delete([]byte(k))
+	}
+	for k, v := range readdedToBatch {
+		batch.Put([]byte(k), v)
+	}
+	require.NoError(t, s.PutBatch(batch))
+	toBe := []map[string][]byte{toStay, toBeStored, readdedToBatch}
+	notToBe := []map[string][]byte{deletedInBatch, toBeDeleted}
+	for _, kvs := range toBe {
+		for k, v := range kvs {
+			value, err := s.Get([]byte(k))
+			assert.Nil(t, err)
+			assert.Equal(t, value, v)
+		}
+	}
+	for _, kvs := range notToBe {
+		for k, v := range kvs {
+			_, err := s.Get([]byte(k))
+			assert.Equal(t, ErrKeyNotFound, err, "%s:%s", k, v)
+		}
+	}
+	require.NoError(t, s.Close())
+}
+
+func TestAllDBs(t *testing.T) {
+	var DBs = []dbSetup{
+		{"BoltDB", newBoltStoreForTesting},
+		{"LevelDB", newLevelDBForTesting},
+		{"Memory", newMemoryStoreForTesting},
+		{"RedisDB", newRedisStoreForTesting},
+	}
+	var tests = []dbTestFunction{testStoreClose, testStorePutAndGet,
+		testStoreGetNonExistent, testStorePutBatch, testStoreSeek,
+		testStoreDeleteNonExistent, testStorePutAndDelete,
+		testStorePutBatchWithDelete}
+	for _, db := range DBs {
+		for _, test := range tests {
+			s := db.create(t)
+			twrapper := func(t *testing.T) {
+				test(t, s)
+			}
+			fname := runtime.FuncForPC(reflect.ValueOf(test).Pointer()).Name()
+			t.Run(db.name+"/"+fname, twrapper)
+		}
+	}
+}

pkg/core/storage_item.go

@@ -0,0 +1,64 @@
+package core
+
+import (
+	"github.com/CityOfZion/neo-go/pkg/core/storage"
+	"github.com/CityOfZion/neo-go/pkg/io"
+	"github.com/CityOfZion/neo-go/pkg/util"
+)
+
+// StorageItem is the value to be stored with read-only flag.
+type StorageItem struct {
+	Value   []byte
+	IsConst bool
+}
+
+// makeStorageItemKey returns a key used to store StorageItem in the DB.
+func makeStorageItemKey(scripthash util.Uint160, key []byte) []byte {
+	return storage.AppendPrefix(storage.STStorage, append(scripthash.BytesReverse(), key...))
+}
+
+// getStorageItemFromStore returns StorageItem if it exists in the given Store.
+func getStorageItemFromStore(s storage.Store, scripthash util.Uint160, key []byte) *StorageItem {
+	b, err := s.Get(makeStorageItemKey(scripthash, key))
+	if err != nil {
+		return nil
+	}
+	r := io.NewBinReaderFromBuf(b)
+
+	si := &StorageItem{}
+	si.DecodeBinary(r)
+	if r.Err != nil {
+		return nil
+	}
+
+	return si
+}
+
+// putStorageItemIntoStore puts given StorageItem for given script with given
+// key into the given Store.
+func putStorageItemIntoStore(s storage.Store, scripthash util.Uint160, key []byte, si *StorageItem) error {
+	buf := io.NewBufBinWriter()
+	si.EncodeBinary(buf.BinWriter)
+	if buf.Err != nil {
+		return buf.Err
+	}
+	return s.Put(makeStorageItemKey(scripthash, key), buf.Bytes())
+}
+
+// deleteStorageItemInStore drops storage item for the given script with the
+// given key from the Store.
+func deleteStorageItemInStore(s storage.Store, scripthash util.Uint160, key []byte) error {
+	return s.Delete(makeStorageItemKey(scripthash, key))
+}
+
+// EncodeBinary implements Serializable interface.
+func (si *StorageItem) EncodeBinary(w *io.BinWriter) {
+	w.WriteBytes(si.Value)
+	w.WriteLE(si.IsConst)
+}
+
+// DecodeBinary implements Serializable interface.
+func (si *StorageItem) DecodeBinary(r *io.BinReader) {
+	si.Value = r.ReadBytes()
+	r.ReadLE(&si.IsConst)
+}

pkg/core/storage_item_test.go

@@ -0,0 +1,26 @@
+package core
+
+import (
+	"testing"
+
+	"github.com/CityOfZion/neo-go/pkg/core/storage"
+	"github.com/CityOfZion/neo-go/pkg/util"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestPutGetDeleteStorageItem(t *testing.T) {
+	s := storage.NewMemoryStore()
+	si := &StorageItem{
+		Value: []byte("smth"),
+	}
+	key := []byte("key")
+	cHash, err := util.Uint160DecodeBytes([]byte("abcdefghijklmnopqrst"))
+	assert.Nil(t, err)
+	assert.NoError(t, putStorageItemIntoStore(s, cHash, key, si))
+	siRead := getStorageItemFromStore(s, cHash, key)
+	assert.NotNil(t, siRead)
+	assert.Equal(t, si, siRead)
+	assert.NoError(t, deleteStorageItemInStore(s, cHash, key))
+	siRead2 := getStorageItemFromStore(s, cHash, key)
+	assert.Nil(t, siRead2)
+}

pkg/crypto/keys/private_key.go

@@ -47,8 +47,8 @@ func NewPrivateKeyFromBytes(b []byte) (*PrivateKey, error) {
 	return &PrivateKey{b}, nil
 }
 
-// NewPrivateKeyFromRawBytes returns a NEO PrivateKey from the ASN.1 serialized keys.
-func NewPrivateKeyFromRawBytes(b []byte) (*PrivateKey, error) {
+// NewPrivateKeyFromASN1 returns a NEO PrivateKey from the ASN.1 serialized key.
+func NewPrivateKeyFromASN1(b []byte) (*PrivateKey, error) {
 	privkey, err := x509.ParseECPrivateKey(b)
 	if err != nil {
 		return nil, err

pkg/crypto/keys/publickey.go

@@ -61,7 +61,7 @@ func NewPublicKeyFromString(s string) (*PublicKey, error) {
 
 // Bytes returns the byte array representation of the public key.
 func (p *PublicKey) Bytes() []byte {
-	if p.isInfinity() {
+	if p.IsInfinity() {
 		return []byte{0x00}
 	}
 
@@ -78,8 +78,8 @@ func (p *PublicKey) Bytes() []byte {
 	return append([]byte{prefix}, paddedX...)
 }
 
-// NewPublicKeyFromRawBytes returns a NEO PublicKey from the ASN.1 serialized keys.
-func NewPublicKeyFromRawBytes(data []byte) (*PublicKey, error) {
+// NewPublicKeyFromASN1 returns a NEO PublicKey from the ASN.1 serialized key.
+func NewPublicKeyFromASN1(data []byte) (*PublicKey, error) {
 	var (
 		err    error
 		pubkey interface{}
@@ -225,14 +225,14 @@ func (p *PublicKey) Verify(signature []byte, hash []byte) bool {
 	return ecdsa.Verify(publicKey, hash, rBytes, sBytes)
 }
 
-// isInfinity checks if point P is infinity on EllipticCurve ec.
-func (p *PublicKey) isInfinity() bool {
+// IsInfinity checks if the key is infinite (null, basically).
+func (p *PublicKey) IsInfinity() bool {
 	return p.X == nil && p.Y == nil
 }
 
 // String implements the Stringer interface.
 func (p *PublicKey) String() string {
-	if p.isInfinity() {
+	if p.IsInfinity() {
 		return "00"
 	}
 	bx := hex.EncodeToString(p.X.Bytes())

pkg/network/helper_test.go

@@ -56,6 +56,9 @@ func (chain testChain) HeaderHeight() uint32 {
 func (chain testChain) GetBlock(hash util.Uint256) (*core.Block, error) {
 	panic("TODO")
 }
+func (chain testChain) GetContractState(hash util.Uint160) *core.ContractState {
+	panic("TODO")
+}
 func (chain testChain) GetHeaderHash(int) util.Uint256 {
 	return util.Uint256{}
 }
@@ -69,6 +72,15 @@ func (chain testChain) GetAssetState(util.Uint256) *core.AssetState {
 func (chain testChain) GetAccountState(util.Uint160) *core.AccountState {
 	panic("TODO")
 }
+func (chain testChain) GetScriptHashesForVerifying(*transaction.Transaction) ([]util.Uint160, error) {
+	panic("TODO")
+}
+func (chain testChain) GetStorageItem(scripthash util.Uint160, key []byte) *core.StorageItem {
+	panic("TODO")
+}
+func (chain testChain) GetStorageItems(hash util.Uint160) (map[string]*core.StorageItem, error) {
+	panic("TODO")
+}
 func (chain testChain) CurrentHeaderHash() util.Uint256 {
 	return util.Uint256{}
 }
@@ -85,6 +97,10 @@ func (chain testChain) GetTransaction(util.Uint256) (*transaction.Transaction, u
 	panic("TODO")
 }
 
+func (chain testChain) GetUnspentCoinState(util.Uint256) *core.UnspentCoinState {
+	panic("TODO")
+}
+
 func (chain testChain) GetMemPool() core.MemPool {
 	panic("TODO")
 }
@@ -93,7 +109,7 @@ func (chain testChain) IsLowPriority(*transaction.Transaction) bool {
 	panic("TODO")
 }
 
-func (chain testChain) Verify(*transaction.Transaction) error {
+func (chain testChain) VerifyTx(*transaction.Transaction, *core.Block) error {
 	panic("TODO")
 }
 

pkg/network/server.go

@@ -399,7 +399,7 @@ func (s *Server) RelayTxn(t *transaction.Transaction) RelayReason {
 	if s.chain.HasTransaction(t.Hash()) {
 		return RelayAlreadyExists
 	}
-	if err := s.chain.Verify(t); err != nil {
+	if err := s.chain.VerifyTx(t, nil); err != nil {
 		return RelayInvalid
 	}
 	// TODO: Implement Plugin.CheckPolicy?

pkg/rpc/server_helper_test.go

@@ -3,18 +3,16 @@ package rpc
 import (
 	"context"
 	"net/http"
+	"os"
 	"testing"
-	"time"
 
 	"github.com/CityOfZion/neo-go/config"
 	"github.com/CityOfZion/neo-go/pkg/core"
 	"github.com/CityOfZion/neo-go/pkg/core/storage"
-	"github.com/CityOfZion/neo-go/pkg/core/transaction"
-	"github.com/CityOfZion/neo-go/pkg/crypto/hash"
+	"github.com/CityOfZion/neo-go/pkg/io"
 	"github.com/CityOfZion/neo-go/pkg/network"
 	"github.com/CityOfZion/neo-go/pkg/rpc/result"
 	"github.com/CityOfZion/neo-go/pkg/rpc/wrappers"
-	"github.com/CityOfZion/neo-go/pkg/util"
 	"github.com/stretchr/testify/require"
 )
 
@@ -142,6 +140,8 @@ type GetAccountStateResponse struct {
 }
 
 func initServerWithInMemoryChain(ctx context.Context, t *testing.T) (*core.Blockchain, http.HandlerFunc) {
+	var nBlocks uint32
+
 	net := config.ModeUnitTestNet
 	configPath := "../../config"
 	cfg, err := config.Load(configPath, net)
@@ -152,7 +152,18 @@ func initServerWithInMemoryChain(ctx context.Context, t *testing.T) (*core.Block
 	require.NoError(t, err, "could not create chain")
 
 	go chain.Run(ctx)
-	initBlocks(t, chain)
+
+	f, err := os.Open("testdata/50testblocks.acc")
+	require.Nil(t, err)
+	br := io.NewBinReaderFromIO(f)
+	br.ReadLE(&nBlocks)
+	require.Nil(t, br.Err)
+	for i := 0; i < int(nBlocks); i++ {
+		block := &core.Block{}
+		block.DecodeBinary(br)
+		require.Nil(t, br.Err)
+		require.NoError(t, chain.AddBlock(block))
+	}
 
 	serverConfig := network.NewServerConfig(cfg)
 	server := network.NewServer(serverConfig, chain)
@@ -161,44 +172,3 @@ func initServerWithInMemoryChain(ctx context.Context, t *testing.T) (*core.Block
 
 	return chain, handler
 }
-
-func initBlocks(t *testing.T, chain *core.Blockchain) {
-	blocks := makeBlocks(10)
-	for i := 0; i < len(blocks); i++ {
-		require.NoError(t, chain.AddBlock(blocks[i]))
-	}
-}
-
-func makeBlocks(n int) []*core.Block {
-	blocks := make([]*core.Block, n)
-	for i := 0; i < n; i++ {
-		blocks[i] = newBlock(uint32(i+1), newTX(transaction.MinerType))
-	}
-	return blocks
-}
-
-func newTX(t transaction.TXType) *transaction.Transaction {
-	return &transaction.Transaction{
-		Type: t,
-	}
-}
-
-func newBlock(index uint32, txs ...*transaction.Transaction) *core.Block {
-	b := &core.Block{
-		BlockBase: core.BlockBase{
-			Version:       0,
-			PrevHash:      hash.Sha256([]byte("a")),
-			MerkleRoot:    hash.Sha256([]byte("b")),
-			Timestamp:     uint32(time.Now().UTC().Unix()),
-			Index:         index,
-			ConsensusData: 1111,
-			NextConsensus: util.Uint160{},
-			Script: &transaction.Witness{
-				VerificationScript: []byte{0x0},
-				InvocationScript:   []byte{0x1},
-			},
-		},
-		Transactions: txs,
-	}
-	return b
-}

pkg/smartcontract/contract.go

@@ -9,6 +9,21 @@ import (
 	"github.com/CityOfZion/neo-go/pkg/vm"
 )
 
+// CreateSignatureRedeemScript creates a check signature script runnable by VM.
+func CreateSignatureRedeemScript(key *keys.PublicKey) ([]byte, error) {
+	buf := new(bytes.Buffer)
+	err := vm.EmitBytes(buf, key.Bytes())
+	if err != nil {
+		return nil, err
+	}
+	err = vm.EmitOpcode(buf, vm.CHECKSIG)
+	if err != nil {
+		return nil, err
+	}
+
+	return buf.Bytes(), nil
+}
+
 // CreateMultiSigRedeemScript will create a script runnable by the VM.
 func CreateMultiSigRedeemScript(m int, publicKeys keys.PublicKeys) ([]byte, error) {
 	if m <= 1 {

pkg/smartcontract/param_context.go

@@ -18,6 +18,17 @@ const (
 	ArrayType
 )
 
+// PropertyState represents contract properties (flags).
+type PropertyState byte
+
+// List of supported properties.
+const (
+	NoProperties               = 0
+	HasStorage   PropertyState = 1 << iota
+	HasDynamicInvoke
+	IsPayable
+)
+
 // Parameter represents a smart contract parameter.
 type Parameter struct {
 	// Type of the parameter

pkg/vm/contract_checks.go

@@ -0,0 +1,98 @@
+package vm
+
+import (
+	"encoding/binary"
+)
+
+func getNumOfThingsFromInstr(instr Instruction, param []byte) (int, bool) {
+	var nthings int
+
+	switch instr {
+	case PUSH1, PUSH2, PUSH3, PUSH4, PUSH5, PUSH6, PUSH7, PUSH8,
+		PUSH9, PUSH10, PUSH11, PUSH12, PUSH13, PUSH14, PUSH15, PUSH16:
+		nthings = int(instr-PUSH1) + 1
+	case PUSHBYTES1:
+		nthings = int(param[0])
+	case PUSHBYTES2:
+		nthings = int(binary.LittleEndian.Uint16(param))
+	default:
+		return 0, false
+	}
+	if nthings < 1 || nthings > MaxArraySize {
+		return 0, false
+	}
+	return nthings, true
+}
+
+// IsMultiSigContract checks whether the passed script is a multi-signature
+// contract.
+func IsMultiSigContract(script []byte) bool {
+	var nsigs, nkeys int
+
+	ctx := NewContext(script)
+	instr, param, err := ctx.Next()
+	if err != nil {
+		return false
+	}
+	nsigs, ok := getNumOfThingsFromInstr(instr, param)
+	if !ok {
+		return false
+	}
+	for {
+		instr, param, err = ctx.Next()
+		if err != nil {
+			return false
+		}
+		if instr != PUSHBYTES33 {
+			break
+		}
+		nkeys++
+		if nkeys > MaxArraySize {
+			return false
+		}
+	}
+	if nkeys < nsigs {
+		return false
+	}
+	nkeys2, ok := getNumOfThingsFromInstr(instr, param)
+	if !ok {
+		return false
+	}
+	if nkeys2 != nkeys {
+		return false
+	}
+	instr, _, err = ctx.Next()
+	if err != nil || instr != CHECKMULTISIG {
+		return false
+	}
+	instr, _, err = ctx.Next()
+	if err != nil || instr != RET || ctx.ip != len(script) {
+		return false
+	}
+	return true
+}
+
+// IsSignatureContract checks whether the passed script is a signature check
+// contract.
+func IsSignatureContract(script []byte) bool {
+	ctx := NewContext(script)
+	instr, _, err := ctx.Next()
+	if err != nil || instr != PUSHBYTES33 {
+		return false
+	}
+	instr, _, err = ctx.Next()
+	if err != nil || instr != CHECKSIG {
+		return false
+	}
+	instr, _, err = ctx.Next()
+	if err != nil || instr != RET || ctx.ip != len(script) {
+		return false
+	}
+	return true
+}
+
+// IsStandardContract checks whether the passed script is a signature or
+// multi-signature contract.
+func IsStandardContract(script []byte) bool {
+	return IsSignatureContract(script) || IsMultiSigContract(script)
+}

pkg/vm/contract_checks_test.go

@@ -0,0 +1,227 @@
+package vm
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestIsSignatureContractGood(t *testing.T) {
+	prog := make([]byte, 35)
+	prog[0] = byte(PUSHBYTES33)
+	prog[34] = byte(CHECKSIG)
+	assert.Equal(t, true, IsSignatureContract(prog))
+	assert.Equal(t, true, IsStandardContract(prog))
+}
+
+func TestIsSignatureContractBadNoCheckSig(t *testing.T) {
+	prog := make([]byte, 34)
+	prog[0] = byte(PUSHBYTES33)
+	assert.Equal(t, false, IsSignatureContract(prog))
+	assert.Equal(t, false, IsStandardContract(prog))
+}
+
+func TestIsSignatureContractBadNoCheckSig2(t *testing.T) {
+	prog := make([]byte, 35)
+	prog[0] = byte(PUSHBYTES33)
+	prog[34] = byte(CHECKMULTISIG)
+	assert.Equal(t, false, IsSignatureContract(prog))
+}
+
+func TestIsSignatureContractBadWrongPush(t *testing.T) {
+	prog := make([]byte, 35)
+	prog[0] = byte(PUSHBYTES32)
+	prog[33] = byte(NOP)
+	prog[34] = byte(CHECKSIG)
+	assert.Equal(t, false, IsSignatureContract(prog))
+}
+
+func TestIsSignatureContractBadWrongInstr(t *testing.T) {
+	prog := make([]byte, 30)
+	prog[0] = byte(PUSHBYTES33)
+	assert.Equal(t, false, IsSignatureContract(prog))
+}
+
+func TestIsSignatureContractBadExcessiveInstr(t *testing.T) {
+	prog := make([]byte, 36)
+	prog[0] = byte(PUSHBYTES33)
+	prog[34] = byte(CHECKSIG)
+	prog[35] = byte(RET)
+	assert.Equal(t, false, IsSignatureContract(prog))
+}
+
+func TestIsMultiSigContractGood(t *testing.T) {
+	prog := make([]byte, 71)
+	prog[0] = byte(PUSH2)
+	prog[1] = byte(PUSHBYTES33)
+	prog[35] = byte(PUSHBYTES33)
+	prog[69] = byte(PUSH2)
+	prog[70] = byte(CHECKMULTISIG)
+	assert.Equal(t, true, IsMultiSigContract(prog))
+	assert.Equal(t, true, IsStandardContract(prog))
+}
+
+func TestIsMultiSigContractGoodPushBytes1(t *testing.T) {
+	prog := make([]byte, 73)
+	prog[0] = byte(PUSHBYTES1)
+	prog[1] = 2
+	prog[2] = byte(PUSHBYTES33)
+	prog[36] = byte(PUSHBYTES33)
+	prog[70] = byte(PUSHBYTES1)
+	prog[71] = 2
+	prog[72] = byte(CHECKMULTISIG)
+	assert.Equal(t, true, IsMultiSigContract(prog))
+}
+
+func TestIsMultiSigContractGoodPushBytes2(t *testing.T) {
+	prog := make([]byte, 75)
+	prog[0] = byte(PUSHBYTES2)
+	prog[1] = 2
+	prog[3] = byte(PUSHBYTES33)
+	prog[37] = byte(PUSHBYTES33)
+	prog[71] = byte(PUSHBYTES2)
+	prog[72] = 2
+	prog[74] = byte(CHECKMULTISIG)
+	assert.Equal(t, true, IsMultiSigContract(prog))
+}
+
+func TestIsMultiSigContractBadNSigs1(t *testing.T) {
+	prog := make([]byte, 71)
+	prog[0] = byte(PUSH0)
+	prog[1] = byte(PUSHBYTES33)
+	prog[35] = byte(PUSHBYTES33)
+	prog[69] = byte(PUSH2)
+	prog[70] = byte(CHECKMULTISIG)
+	assert.Equal(t, false, IsMultiSigContract(prog))
+	assert.Equal(t, false, IsStandardContract(prog))
+}
+
+func TestIsMultiSigContractBadNSigs2(t *testing.T) {
+	prog := make([]byte, 73)
+	prog[0] = byte(PUSHBYTES2)
+	prog[1] = 0xff
+	prog[2] = 0xff
+	prog[3] = byte(PUSHBYTES33)
+	prog[37] = byte(PUSHBYTES33)
+	prog[71] = byte(PUSH2)
+	prog[72] = byte(CHECKMULTISIG)
+	assert.Equal(t, false, IsMultiSigContract(prog))
+}
+
+func TestIsMultiSigContractBadNSigs3(t *testing.T) {
+	prog := make([]byte, 71)
+	prog[0] = byte(PUSH5)
+	prog[1] = byte(PUSHBYTES33)
+	prog[35] = byte(PUSHBYTES33)
+	prog[69] = byte(PUSH2)
+	prog[70] = byte(CHECKMULTISIG)
+	assert.Equal(t, false, IsMultiSigContract(prog))
+}
+
+func TestIsMultiSigContractBadExcessiveNOP1(t *testing.T) {
+	prog := make([]byte, 72)
+	prog[0] = byte(PUSH2)
+	prog[1] = byte(NOP)
+	prog[2] = byte(PUSHBYTES33)
+	prog[36] = byte(PUSHBYTES33)
+	prog[70] = byte(PUSH2)
+	prog[71] = byte(CHECKMULTISIG)
+	assert.Equal(t, false, IsMultiSigContract(prog))
+}
+
+func TestIsMultiSigContractBadExcessiveNOP2(t *testing.T) {
+	prog := make([]byte, 72)
+	prog[0] = byte(PUSH2)
+	prog[1] = byte(PUSHBYTES33)
+	prog[35] = byte(NOP)
+	prog[36] = byte(PUSHBYTES33)
+	prog[70] = byte(PUSH2)
+	prog[71] = byte(CHECKMULTISIG)
+	assert.Equal(t, false, IsMultiSigContract(prog))
+}
+
+func TestIsMultiSigContractBadExcessiveNOP3(t *testing.T) {
+	prog := make([]byte, 72)
+	prog[0] = byte(PUSH2)
+	prog[1] = byte(PUSHBYTES33)
+	prog[35] = byte(PUSHBYTES33)
+	prog[69] = byte(NOP)
+	prog[70] = byte(PUSH2)
+	prog[71] = byte(CHECKMULTISIG)
+	assert.Equal(t, false, IsMultiSigContract(prog))
+}
+
+func TestIsMultiSigContractBadExcessiveNOP4(t *testing.T) {
+	prog := make([]byte, 72)
+	prog[0] = byte(PUSH2)
+	prog[1] = byte(PUSHBYTES33)
+	prog[35] = byte(PUSHBYTES33)
+	prog[69] = byte(PUSH2)
+	prog[70] = byte(NOP)
+	prog[71] = byte(CHECKMULTISIG)
+	assert.Equal(t, false, IsMultiSigContract(prog))
+}
+
+func TestIsMultiSigContractBadExcessiveNOP5(t *testing.T) {
+	prog := make([]byte, 72)
+	prog[0] = byte(PUSH2)
+	prog[1] = byte(PUSHBYTES33)
+	prog[35] = byte(PUSHBYTES33)
+	prog[69] = byte(PUSH2)
+	prog[70] = byte(CHECKMULTISIG)
+	prog[71] = byte(NOP)
+	assert.Equal(t, false, IsMultiSigContract(prog))
+}
+
+func TestIsMultiSigContractBadNKeys1(t *testing.T) {
+	prog := make([]byte, 71)
+	prog[0] = byte(PUSH2)
+	prog[1] = byte(PUSHBYTES33)
+	prog[35] = byte(PUSHBYTES33)
+	prog[69] = byte(PUSH3)
+	prog[70] = byte(CHECKMULTISIG)
+	assert.Equal(t, false, IsMultiSigContract(prog))
+}
+
+func TestIsMultiSigContractBadNKeys2(t *testing.T) {
+	prog := make([]byte, 1)
+	prog[0] = byte(PUSH10)
+	key := make([]byte, 33)
+	var asize = uint16(MaxArraySize + 1)
+	for i := 0; i < int(asize); i++ {
+		prog = append(prog, byte(PUSHBYTES33))
+		prog = append(prog, key...)
+	}
+	prog = append(prog, byte(PUSHBYTES2), byte(asize&0xff), byte((asize<<8)&0xff), byte(CHECKMULTISIG))
+	assert.Equal(t, false, IsMultiSigContract(prog))
+}
+
+func TestIsMultiSigContractBadRead1(t *testing.T) {
+	prog := make([]byte, 71)
+	prog[0] = byte(PUSHBYTES75)
+	prog[1] = byte(PUSHBYTES33)
+	prog[35] = byte(PUSHBYTES33)
+	prog[69] = byte(PUSH2)
+	prog[70] = byte(CHECKMULTISIG)
+	assert.Equal(t, false, IsMultiSigContract(prog))
+}
+
+func TestIsMultiSigContractBadRead2(t *testing.T) {
+	prog := make([]byte, 71)
+	prog[0] = byte(PUSH2)
+	prog[1] = byte(PUSHBYTES33)
+	prog[35] = byte(PUSHBYTES75)
+	prog[69] = byte(PUSH2)
+	prog[70] = byte(CHECKMULTISIG)
+	assert.Equal(t, false, IsMultiSigContract(prog))
+}
+
+func TestIsMultiSigContractBadRead3(t *testing.T) {
+	prog := make([]byte, 71)
+	prog[0] = byte(PUSH2)
+	prog[1] = byte(PUSHBYTES33)
+	prog[35] = byte(PUSHBYTES33)
+	prog[69] = byte(PUSH2)
+	prog[70] = byte(PUSHBYTES1)
+	assert.Equal(t, false, IsMultiSigContract(prog))
+}

pkg/vm/stack_item.go

@@ -1,6 +1,7 @@
 package vm
 
 import (
+	"encoding/binary"
 	"encoding/json"
 	"fmt"
 	"math/big"
@@ -23,10 +24,26 @@ func makeStackItem(v interface{}) StackItem {
 		return &BigIntegerItem{
 			value: big.NewInt(val),
 		}
+	case uint8:
+		return &BigIntegerItem{
+			value: big.NewInt(int64(val)),
+		}
+	case uint16:
+		return &BigIntegerItem{
+			value: big.NewInt(int64(val)),
+		}
 	case uint32:
 		return &BigIntegerItem{
 			value: big.NewInt(int64(val)),
 		}
+	case uint64:
+		b := make([]byte, 8)
+		binary.BigEndian.PutUint64(b, val)
+		bigInt := big.NewInt(0)
+		bigInt.SetBytes(b)
+		return &BigIntegerItem{
+			value: bigInt,
+		}
 	case []byte:
 		return &ByteArrayItem{
 			value: val,