all: fix ineffectual assignments and remove uses of crypto.Sha3

go get github.com/gordonklaus/ineffassign
ineffassign .

accounts/abi/bind/base.go

@@ -170,7 +170,7 @@ func (c *BoundContract) transact(opts *TransactOpts, contract *common.Address, i
 	if value == nil {
 		value = new(big.Int)
 	}
-	nonce := uint64(0)
+	var nonce uint64
 	if opts.Nonce == nil {
 		nonce, err = c.transactor.PendingNonceAt(ensureContext(opts.Context), opts.From)
 		if err != nil {

accounts/accounts_test.go

@@ -115,6 +115,9 @@ func TestTimedUnlock(t *testing.T) {
 
 	pass := "foo"
 	a1, err := am.NewAccount(pass)
+	if err != nil {
+		t.Fatal(err)
+	}
 
 	// Signing without passphrase fails because account is locked
 	_, err = am.Sign(a1.Address, testSigData)
@@ -147,6 +150,9 @@ func TestOverrideUnlock(t *testing.T) {
 
 	pass := "foo"
 	a1, err := am.NewAccount(pass)
+	if err != nil {
+		t.Fatal(err)
+	}
 
 	// Unlock indefinitely.
 	if err = am.TimedUnlock(a1, pass, 5*time.Minute); err != nil {

accounts/presale.go

@@ -22,6 +22,7 @@ import (
 	"crypto/sha256"
 	"encoding/hex"
 	"encoding/json"
+	"errors"
 	"fmt"
 
 	"github.com/ethereum/go-ethereum/crypto"
@@ -53,6 +54,9 @@ func decryptPreSaleKey(fileContent []byte, password string) (key *Key, err error
 		return nil, err
 	}
 	encSeedBytes, err := hex.DecodeString(preSaleKeyStruct.EncSeed)
+	if err != nil {
+		return nil, errors.New("invalid hex in encSeed")
+	}
 	iv := encSeedBytes[:16]
 	cipherText := encSeedBytes[16:]
 	/*

cmd/geth/monitorcmd.go

@@ -236,8 +236,9 @@ func expandMetrics(metrics map[string]interface{}, path string) []string {
 
 // fetchMetric iterates over the metrics map and retrieves a specific one.
 func fetchMetric(metrics map[string]interface{}, metric string) float64 {
-	parts, found := strings.Split(metric, "/"), true
+	parts := strings.Split(metric, "/")
 	for _, part := range parts[:len(parts)-1] {
+		var found bool
 		metrics, found = metrics[part].(map[string]interface{})
 		if !found {
 			return 0

cmd/utils/customflags.go

@@ -54,15 +54,10 @@ type DirectoryFlag struct {
 }
 
 func (self DirectoryFlag) String() string {
-	var fmtString string
-	fmtString = "%s %v\t%v"
-
+	fmtString := "%s %v\t%v"
 	if len(self.Value.Value) > 0 {
 		fmtString = "%s \"%v\"\t%v"
-	} else {
-		fmtString = "%s %v\t%v"
 	}
-
 	return withEnvHint(self.EnvVar, fmt.Sprintf(fmtString, prefixedNames(self.Name), self.Value.Value, self.Usage))
 }
 

console/console.go

@@ -226,8 +226,8 @@ func (c *Console) AutoCompleteInput(line string, pos int) (string, []string, str
 	}
 	// Chunck data to relevant part for autocompletion
 	// E.g. in case of nested lines eth.getBalance(eth.coinb<tab><tab>
-	start := 0
-	for start = pos - 1; start > 0; start-- {
+	start := pos - 1
+	for ; start > 0; start-- {
 		// Skip all methods and namespaces (i.e. including te dot)
 		if line[start] == '.' || (line[start] >= 'a' && line[start] <= 'z') || (line[start] >= 'A' && line[start] <= 'Z') {
 			continue

contracts/chequebook/cheque_test.go

@@ -73,8 +73,8 @@ func TestIssueAndReceive(t *testing.T) {
 	}
 	chbook.sent[addr1] = new(big.Int).SetUint64(42)
 	amount := common.Big1
-	ch, err := chbook.Issue(addr1, amount)
-	if err == nil {
+
+	if _, err = chbook.Issue(addr1, amount); err == nil {
 		t.Fatalf("expected insufficient funds error, got none")
 	}
 
@@ -83,7 +83,7 @@ func TestIssueAndReceive(t *testing.T) {
 		t.Fatalf("expected: %v, got %v", "0", chbook.Balance())
 	}
 
-	ch, err = chbook.Issue(addr1, amount)
+	ch, err := chbook.Issue(addr1, amount)
 	if err != nil {
 		t.Fatalf("expected no error, got %v", err)
 	}
@@ -128,8 +128,8 @@ func TestCheckbookFile(t *testing.T) {
 		t.Errorf("expected: %v, got %v", "0", chbook.Balance())
 	}
 
-	ch, err := chbook.Issue(addr1, common.Big1)
-	if err != nil {
+	var ch *Cheque
+	if ch, err = chbook.Issue(addr1, common.Big1); err != nil {
 		t.Fatalf("expected no error, got %v", err)
 	}
 	if ch.Amount.Cmp(new(big.Int).SetUint64(43)) != 0 {
@@ -155,7 +155,7 @@ func TestVerifyErrors(t *testing.T) {
 	}
 
 	path1 := filepath.Join(os.TempDir(), "chequebook-test-1.json")
-	contr1, err := deploy(key1, common.Big2, backend)
+	contr1, _ := deploy(key1, common.Big2, backend)
 	chbook1, err := NewChequebook(path1, contr1, key1, backend)
 	if err != nil {
 		t.Errorf("expected no error, got %v", err)
@@ -223,7 +223,8 @@ func TestVerifyErrors(t *testing.T) {
 func TestDeposit(t *testing.T) {
 	path0 := filepath.Join(os.TempDir(), "chequebook-test-0.json")
 	backend := newTestBackend()
-	contr0, err := deploy(key0, new(big.Int), backend)
+	contr0, _ := deploy(key0, new(big.Int), backend)
+
 	chbook, err := NewChequebook(path0, contr0, key0, backend)
 	if err != nil {
 		t.Errorf("expected no error, got %v", err)
@@ -361,7 +362,8 @@ func TestDeposit(t *testing.T) {
 func TestCash(t *testing.T) {
 	path := filepath.Join(os.TempDir(), "chequebook-test.json")
 	backend := newTestBackend()
-	contr0, err := deploy(key0, common.Big2, backend)
+	contr0, _ := deploy(key0, common.Big2, backend)
+
 	chbook, err := NewChequebook(path, contr0, key0, backend)
 	if err != nil {
 		t.Errorf("expected no error, got %v", err)
@@ -380,11 +382,12 @@ func TestCash(t *testing.T) {
 	}
 
 	// cashing latest cheque
-	_, err = chbox.Receive(ch)
-	if err != nil {
+	if _, err = chbox.Receive(ch); err != nil {
 		t.Fatalf("expected no error, got %v", err)
 	}
-	_, err = ch.Cash(chbook.session)
+	if _, err = ch.Cash(chbook.session); err != nil {
+		t.Fatal("Cash failed:", err)
+	}
 	backend.Commit()
 
 	chbook.balance = new(big.Int).Set(common.Big3)

contracts/ens/ens_test.go

@@ -29,7 +29,7 @@ import (
 var (
 	key, _ = crypto.HexToECDSA("b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291")
 	name   = "my name on ENS"
-	hash   = crypto.Sha3Hash([]byte("my content"))
+	hash   = crypto.Keccak256Hash([]byte("my content"))
 	addr   = crypto.PubkeyToAddress(key.PublicKey)
 )
 

core/blockchain.go

@@ -1054,11 +1054,10 @@ func (st *insertStats) report(chain []*types.Block, index int) {
 		start, end := chain[st.lastIndex], chain[index]
 		txcount := countTransactions(chain[st.lastIndex : index+1])
 
-		extra := ""
+		var hashes, extra string
 		if st.queued > 0 || st.ignored > 0 {
 			extra = fmt.Sprintf(" (%d queued %d ignored)", st.queued, st.ignored)
 		}
-		hashes := ""
 		if st.processed > 1 {
 			hashes = fmt.Sprintf("%x… / %x…", start.Hash().Bytes()[:4], end.Hash().Bytes()[:4])
 		} else {

core/state/managed_state_test.go

@@ -88,20 +88,20 @@ func TestRemoteNonceChange(t *testing.T) {
 		nn[i] = true
 	}
 	account.nonces = append(account.nonces, nn...)
-	nonce := ms.NewNonce(addr)
+	ms.NewNonce(addr)
 
 	ms.StateDB.stateObjects[addr].data.Nonce = 200
-	nonce = ms.NewNonce(addr)
+	nonce := ms.NewNonce(addr)
 	if nonce != 200 {
-		t.Error("expected nonce after remote update to be", 201, "got", nonce)
+		t.Error("expected nonce after remote update to be", 200, "got", nonce)
 	}
 	ms.NewNonce(addr)
 	ms.NewNonce(addr)
 	ms.NewNonce(addr)
 	ms.StateDB.stateObjects[addr].data.Nonce = 200
 	nonce = ms.NewNonce(addr)
 	if nonce != 204 {
-		t.Error("expected nonce after remote update to be", 201, "got", nonce)
+		t.Error("expected nonce after remote update to be", 204, "got", nonce)
 	}
 }
 

crypto/secp256k1/secp256_test.go

@@ -129,17 +129,12 @@ func signAndRecoverWithRandomMessages(t *testing.T, keys func() ([]byte, []byte)
 }
 
 func TestRecoveryOfRandomSignature(t *testing.T) {
-	pubkey1, seckey := GenerateKeyPair()
+	pubkey1, _ := GenerateKeyPair()
 	msg := randentropy.GetEntropyCSPRNG(32)
-	sig, err := Sign(msg, seckey)
-	if err != nil {
-		t.Errorf("signature error: %s", err)
-	}
 
 	for i := 0; i < TestCount; i++ {
-		sig = randSig()
-		pubkey2, _ := RecoverPubkey(msg, sig)
 		// recovery can sometimes work, but if so should always give wrong pubkey
+		pubkey2, _ := RecoverPubkey(msg, randSig())
 		if bytes.Equal(pubkey1, pubkey2) {
 			t.Fatalf("iteration: %d: pubkey mismatch: do NOT want %x: ", i, pubkey2)
 		}

eth/downloader/downloader_test.go

@@ -650,7 +650,7 @@ func assertOwnForkedChain(t *testing.T, tester *downloadTester, common int, leng
 	}
 	// Verify the state trie too for fast syncs
 	if tester.downloader.mode == FastSync {
-		index := 0
+		var index int
 		if pivot := int(tester.downloader.queue.fastSyncPivot); pivot < common {
 			index = pivot
 		} else {

les/odr_requests.go

@@ -267,8 +267,7 @@ func (self *CodeRequest) Valid(db ethdb.Database, msg *Msg) bool {
 		return false
 	}
 	data := reply[0]
-	hash := crypto.Sha3Hash(data)
-	if !bytes.Equal(self.Hash[:], hash[:]) {
+	if hash := crypto.Keccak256Hash(data); self.Hash != hash {
 		glog.V(logger.Debug).Infof("ODR: requested hash %08x does not match received data hash %08x", self.Hash[:4], hash[:4])
 		return false
 	}

metrics/disk_linux.go

@@ -47,15 +47,16 @@ func ReadDiskStats(stats *DiskStats) error {
 			}
 			return err
 		}
-		key, value := "", int64(0)
-		if parts := strings.Split(line, ":"); len(parts) != 2 {
+		parts := strings.Split(line, ":")
+		if len(parts) != 2 {
 			continue
-		} else {
-			key = strings.TrimSpace(parts[0])
-			if value, err = strconv.ParseInt(strings.TrimSpace(parts[1]), 10, 64); err != nil {
-				return err
-			}
 		}
+		key := strings.TrimSpace(parts[0])
+		value, err := strconv.ParseInt(strings.TrimSpace(parts[1]), 10, 64)
+		if err != nil {
+			return err
+		}
+
 		// Update the counter based on the key
 		switch key {
 		case "syscr":

node/config_test.go

@@ -121,8 +121,7 @@ func TestNodeKeyPersistency(t *testing.T) {
 	if _, err := os.Stat(keyfile); err != nil {
 		t.Fatalf("node key not persisted to data directory: %v", err)
 	}
-	key, err = crypto.LoadECDSA(keyfile)
-	if err != nil {
+	if _, err = crypto.LoadECDSA(keyfile); err != nil {
 		t.Fatalf("failed to load freshly persisted node key: %v", err)
 	}
 	blob1, err := ioutil.ReadFile(keyfile)

p2p/rlpx.go

@@ -429,21 +429,21 @@ func (msg *authMsgV4) decodePlain(input []byte) {
 	n := copy(msg.Signature[:], input)
 	n += shaLen // skip sha3(initiator-ephemeral-pubk)
 	n += copy(msg.InitiatorPubkey[:], input[n:])
-	n += copy(msg.Nonce[:], input[n:])
+	copy(msg.Nonce[:], input[n:])
 	msg.Version = 4
 	msg.gotPlain = true
 }
 
 func (msg *authRespV4) sealPlain(hs *encHandshake) ([]byte, error) {
 	buf := make([]byte, authRespLen)
 	n := copy(buf, msg.RandomPubkey[:])
-	n += copy(buf[n:], msg.Nonce[:])
+	copy(buf[n:], msg.Nonce[:])
 	return ecies.Encrypt(rand.Reader, hs.remotePub, buf, nil, nil)
 }
 
 func (msg *authRespV4) decodePlain(input []byte) {
 	n := copy(msg.RandomPubkey[:], input)
-	n += copy(msg.Nonce[:], input[n:])
+	copy(msg.Nonce[:], input[n:])
 	msg.Version = 4
 }
 

rpc/subscription_test.go

@@ -141,7 +141,7 @@ func TestNotifications(t *testing.T) {
 	}
 
 	var ok bool
-	if subid, ok = response.Result.(string); !ok {
+	if _, ok = response.Result.(string); !ok {
 		t.Fatalf("expected subscription id, got %T", response.Result)
 	}
 

swarm/api/api.go

@@ -140,8 +140,11 @@ func (self *Api) Put(content, contentType string) (string, error) {
 // to resolve path to content using dpa retrieve
 // it returns a section reader, mimeType, status and an error
 func (self *Api) Get(uri string, nameresolver bool) (reader storage.LazySectionReader, mimeType string, status int, err error) {
-
 	key, _, path, err := self.parseAndResolve(uri, nameresolver)
+	if err != nil {
+		return nil, "", 500, fmt.Errorf("can't resolve: %v", err)
+	}
+
 	quitC := make(chan bool)
 	trie, err := loadManifest(self.dpa, key, quitC)
 	if err != nil {
@@ -166,6 +169,10 @@ func (self *Api) Get(uri string, nameresolver bool) (reader storage.LazySectionR
 
 func (self *Api) Modify(uri, contentHash, contentType string, nameresolver bool) (newRootHash string, err error) {
 	root, _, path, err := self.parseAndResolve(uri, nameresolver)
+	if err != nil {
+		return "", fmt.Errorf("can't resolve: %v", err)
+	}
+
 	quitC := make(chan bool)
 	trie, err := loadManifest(self.dpa, root, quitC)
 	if err != nil {

swarm/api/config.go

@@ -69,7 +69,7 @@ func NewConfig(path string, contract common.Address, prvKey *ecdsa.PrivateKey, n
 	var data []byte
 	pubkey := crypto.FromECDSAPub(&prvKey.PublicKey)
 	pubkeyhex := common.ToHex(pubkey)
-	keyhex := crypto.Sha3Hash(pubkey).Hex()
+	keyhex := crypto.Keccak256Hash(pubkey).Hex()
 
 	self = &Config{
 		SyncParams:    network.NewSyncParams(dirpath),

swarm/api/filesystem.go

@@ -241,24 +241,7 @@ func (self *FileSystem) Download(bzzpath, localpath string) error {
 		}
 		go func(i int, entry *downloadListEntry) {
 			defer wg.Done()
-			f, err := os.Create(entry.path) // TODO: path separators
-			if err == nil {
-
-				reader := self.api.dpa.Retrieve(entry.key)
-				writer := bufio.NewWriter(f)
-				size, err := reader.Size(quitC)
-				if err == nil {
-					_, err = io.CopyN(writer, reader, size) // TODO: handle errors
-					err2 := writer.Flush()
-					if err == nil {
-						err = err2
-					}
-					err2 = f.Close()
-					if err == nil {
-						err = err2
-					}
-				}
-			}
+			err := retrieveToFile(quitC, self.api.dpa, entry.key, entry.path)
 			if err != nil {
 				select {
 				case errC <- err:
@@ -279,5 +262,24 @@ func (self *FileSystem) Download(bzzpath, localpath string) error {
 	case <-quitC:
 		return fmt.Errorf("aborted")
 	}
+}
 
+func retrieveToFile(quitC chan bool, dpa *storage.DPA, key storage.Key, path string) error {
+	f, err := os.Create(path) // TODO: path separators
+	if err != nil {
+		return err
+	}
+	reader := dpa.Retrieve(key)
+	writer := bufio.NewWriter(f)
+	size, err := reader.Size(quitC)
+	if err != nil {
+		return err
+	}
+	if _, err = io.CopyN(writer, reader, size); err != nil {
+		return err
+	}
+	if err := writer.Flush(); err != nil {
+		return err
+	}
+	return f.Close()
 }