keys: rename Signature to GetScriptHash, make it return Uint160

Signature itself wasn't used at all and its name is very misleading, Uint160
script hash is way more useful.

pkg/consensus/consensus.go

@@ -11,7 +11,6 @@ import (
 	coreb "github.com/CityOfZion/neo-go/pkg/core/block"
 	"github.com/CityOfZion/neo-go/pkg/core/mempool"
 	"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"
@@ -221,16 +220,15 @@ func (s *service) validatePayload(p *Payload) bool {
 	}
 
 	pub := validators[p.validatorIndex]
-	vs := pub.(*publicKey).GetVerificationScript()
+	h := pub.(*publicKey).GetScriptHash()
-	h := hash.Hash160(vs)
 
 	return p.Verify(h)
 }
 
 func (s *service) getKeyPair(pubs []crypto.PublicKey) (int, crypto.PrivateKey, crypto.PublicKey) {
 	for i := range pubs {
-		script := pubs[i].(*publicKey).GetVerificationScript()
+		sh := pubs[i].(*publicKey).GetScriptHash()
-		acc := s.wallet.GetAccount(hash.Hash160(script))
+		acc := s.wallet.GetAccount(sh)
 		if acc == nil {
 			continue
 		}
@@ -446,7 +444,7 @@ func (s *service) getVerifiedTx(count int) []block.Transaction {
 		sh := s.wallet.GetChangeAddress()
 		if sh.Equals(util.Uint160{}) {
 			pk := s.dbft.Pub.(*publicKey)
-			sh = hash.Hash160(pk.GetVerificationScript())
+			sh = pk.GetScriptHash()
 		}
 		txOuts = []transaction.Output{transaction.Output{
 			AssetID:    core.UtilityTokenID(),

pkg/core/interop_system.go

@@ -8,7 +8,6 @@ import (
 	"github.com/CityOfZion/neo-go/pkg/core/block"
 	"github.com/CityOfZion/neo-go/pkg/core/state"
 	"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/trigger"
 	"github.com/CityOfZion/neo-go/pkg/util"
@@ -311,7 +310,7 @@ func (ic *interopContext) checkHashedWitness(hash util.Uint160) (bool, error) {
 // 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) {
-	return ic.checkHashedWitness(hash.Hash160(key.GetVerificationScript()))
+	return ic.checkHashedWitness(key.GetScriptHash())
 }
 
 // runtimeCheckWitness checks witnesses.

pkg/crypto/keys/private_key.go

@@ -10,6 +10,7 @@ import (
 	"fmt"
 	"math/big"
 
+	"github.com/CityOfZion/neo-go/pkg/util"
 	"github.com/nspcc-dev/rfc6979"
 )
 
@@ -98,10 +99,11 @@ func (p *PrivateKey) Address() string {
 	return pk.Address()
 }
 
-// Signature creates the signature using the private key.
+// GetScriptHash returns verification script hash for public key associated with
-func (p *PrivateKey) Signature() []byte {
+// the private key.
+func (p *PrivateKey) GetScriptHash() util.Uint160 {
 	pk := p.PublicKey()
-	return pk.Signature()
+	return pk.GetScriptHash()
 }
 
 // Sign signs arbitrary length data using the private key.

pkg/crypto/keys/publickey.go

@@ -12,6 +12,7 @@ import (
 	"github.com/CityOfZion/neo-go/pkg/crypto/hash"
 	"github.com/CityOfZion/neo-go/pkg/encoding/address"
 	"github.com/CityOfZion/neo-go/pkg/io"
+	"github.com/CityOfZion/neo-go/pkg/util"
 	"github.com/CityOfZion/neo-go/pkg/vm/opcode"
 	"github.com/pkg/errors"
 )
@@ -233,18 +234,14 @@ func (p *PublicKey) GetVerificationScript() []byte {
 	return b
 }
 
-// Signature returns a NEO-specific hash of the key.
+// GetScriptHash returns a Hash160 of verification script for the key.
-func (p *PublicKey) Signature() []byte {
+func (p *PublicKey) GetScriptHash() util.Uint160 {
-	sig := hash.Hash160(p.GetVerificationScript())
+	return hash.Hash160(p.GetVerificationScript())
-
-	return sig.BytesBE()
 }
 
 // Address returns a base58-encoded NEO-specific address based on the key hash.
 func (p *PublicKey) Address() string {
-	sig := hash.Hash160(p.GetVerificationScript())
+	return address.Uint160ToString(p.GetScriptHash())
-
-	return address.Uint160ToString(sig)
 }
 
 // Verify returns true if the signature is valid and corresponds