all: more linters (#24783)

This enables the following linters

- typecheck
- unused
- staticcheck
- bidichk
- durationcheck
- exportloopref
- gosec

WIth a few exceptions.

- We use a deprecated protobuf in trezor. I didn't want to mess with that, since I cannot meaningfully test any changes there.
- The deprecated TypeMux is used in a few places still, so the warning for it is silenced for now.
- Using string type in context.WithValue is apparently wrong, one should use a custom type, to prevent collisions between different places in the hierarchy of callers. That should be fixed at some point, but may require some attention.
- The warnings for using weak random generator are squashed, since we use a lot of random without need for cryptographic guarantees.

cmd/devp2p/internal/ethtest/snap.go

@@ -104,6 +104,7 @@ func (s *Suite) TestSnapGetAccountRange(t *utesting.T) {
 		// Max bytes: 0. Expect to deliver one account.
 		{0, root, zero, ffHash, 1, firstKey, firstKey},
 	} {
+		tc := tc
 		if err := s.snapGetAccountRange(t, &tc); err != nil {
 			t.Errorf("test %d \n root: %x\n range: %#x - %#x\n bytes: %d\nfailed: %v", i, tc.root, tc.origin, tc.limit, tc.nBytes, err)
 		}
@@ -194,6 +195,7 @@ func (s *Suite) TestSnapGetStorageRanges(t *utesting.T) {
 			expSlots: 2,
 		},
 	} {
+		tc := tc
 		if err := s.snapGetStorageRanges(t, &tc); err != nil {
 			t.Errorf("test %d \n root: %x\n range: %#x - %#x\n bytes: %d\n #accounts: %d\nfailed: %v",
 				i, tc.root, tc.origin, tc.limit, tc.nBytes, len(tc.accounts), err)
@@ -291,6 +293,7 @@ func (s *Suite) TestSnapGetByteCodes(t *utesting.T) {
 			expHashes: 4,
 		},
 	} {
+		tc := tc
 		if err := s.snapGetByteCodes(t, &tc); err != nil {
 			t.Errorf("test %d \n bytes: %d\n #hashes: %d\nfailed: %v", i, tc.nBytes, len(tc.hashes), err)
 		}
@@ -436,6 +439,7 @@ func (s *Suite) TestSnapTrieNodes(t *utesting.T) {
 			},
 		},
 	} {
+		tc := tc
 		if err := s.snapGetTrieNodes(t, &tc); err != nil {
 			t.Errorf("test %d \n #hashes %x\n root: %#x\n bytes: %d\nfailed: %v", i, len(tc.expHashes), tc.root, tc.nBytes, err)
 		}

cmd/devp2p/internal/v5test/framework.go

@@ -60,11 +60,9 @@ type conn struct {
 	remoteAddr *net.UDPAddr
 	listeners  []net.PacketConn
 
-	log           logger
-	codec         *v5wire.Codec
-	lastRequest   v5wire.Packet
-	lastChallenge *v5wire.Whoareyou
-	idCounter     uint32
+	log       logger
+	codec     *v5wire.Codec
+	idCounter uint32
 }
 
 type logger interface {

cmd/geth/accountcmd.go

@@ -239,14 +239,15 @@ func ambiguousAddrRecovery(ks *keystore.KeyStore, err *keystore.AmbiguousAddrErr
 	}
 	fmt.Println("Testing your password against all of them...")
 	var match *accounts.Account
-	for _, a := range err.Matches {
-		if err := ks.Unlock(a, auth); err == nil {
-			match = &a
+	for i, a := range err.Matches {
+		if e := ks.Unlock(a, auth); e == nil {
+			match = &err.Matches[i]
 			break
 		}
 	}
 	if match == nil {
 		utils.Fatalf("None of the listed files could be unlocked.")
+		return accounts.Account{}
 	}
 	fmt.Printf("Your password unlocked %s\n", match.URL)
 	fmt.Println("In order to avoid this warning, you need to remove the following duplicate key files:")

cmd/geth/les_test.go

@@ -81,41 +81,6 @@ func (g *gethrpc) getNodeInfo() *p2p.NodeInfo {
 	return g.nodeInfo
 }
 
-func (g *gethrpc) waitSynced() {
-	// Check if it's synced now
-	var result interface{}
-	g.callRPC(&result, "eth_syncing")
-	syncing, ok := result.(bool)
-	if ok && !syncing {
-		g.geth.Logf("%v already synced", g.name)
-		return
-	}
-
-	// Actually wait, subscribe to the event
-	ch := make(chan interface{})
-	sub, err := g.rpc.Subscribe(context.Background(), "eth", ch, "syncing")
-	if err != nil {
-		g.geth.Fatalf("%v syncing: %v", g.name, err)
-	}
-	defer sub.Unsubscribe()
-	timeout := time.After(4 * time.Second)
-	select {
-	case ev := <-ch:
-		g.geth.Log("'syncing' event", ev)
-		syncing, ok := ev.(bool)
-		if ok && !syncing {
-			break
-		}
-		g.geth.Log("Other 'syncing' event", ev)
-	case err := <-sub.Err():
-		g.geth.Fatalf("%v notification: %v", g.name, err)
-		break
-	case <-timeout:
-		g.geth.Fatalf("%v timeout syncing", g.name)
-		break
-	}
-}
-
 // ipcEndpoint resolves an IPC endpoint based on a configured value, taking into
 // account the set data folders as well as the designated platform we're currently
 // running on.

cmd/puppeth/ssh.go

@@ -30,7 +30,7 @@ import (
 	"github.com/ethereum/go-ethereum/log"
 	"golang.org/x/crypto/ssh"
 	"golang.org/x/crypto/ssh/agent"
-	"golang.org/x/crypto/ssh/terminal"
+	"golang.org/x/term"
 )
 
 // sshClient is a small wrapper around Go's SSH client with a few utility methods
@@ -101,7 +101,7 @@ func dial(server string, pubkey []byte) (*sshClient, error) {
 			key, err := ssh.ParsePrivateKey(buf)
 			if err != nil {
 				fmt.Printf("What's the decryption password for %s? (won't be echoed)\n>", path)
-				blob, err := terminal.ReadPassword(int(os.Stdin.Fd()))
+				blob, err := term.ReadPassword(int(os.Stdin.Fd()))
 				fmt.Println()
 				if err != nil {
 					log.Warn("Couldn't read password", "err", err)
@@ -118,7 +118,7 @@ func dial(server string, pubkey []byte) (*sshClient, error) {
 		}
 		auths = append(auths, ssh.PasswordCallback(func() (string, error) {
 			fmt.Printf("What's the login password for %s at %s? (won't be echoed)\n> ", username, server)
-			blob, err := terminal.ReadPassword(int(os.Stdin.Fd()))
+			blob, err := term.ReadPassword(int(os.Stdin.Fd()))
 
 			fmt.Println()
 			return string(blob), err

cmd/puppeth/wizard.go

@@ -34,7 +34,7 @@ import (
 	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/log"
 	"github.com/peterh/liner"
-	"golang.org/x/crypto/ssh/terminal"
+	"golang.org/x/term"
 )
 
 // config contains all the configurations needed by puppeth that should be saved
@@ -228,7 +228,7 @@ func (w *wizard) readDefaultFloat(def float64) float64 {
 // line and returns it. The input will not be echoed.
 func (w *wizard) readPassword() string {
 	fmt.Printf("> ")
-	text, err := terminal.ReadPassword(int(os.Stdin.Fd()))
+	text, err := term.ReadPassword(int(os.Stdin.Fd()))
 	if err != nil {
 		log.Crit("Failed to read password", "err", err)
 	}

cmd/utils/diskusage.go

@@ -33,6 +33,7 @@ func getFreeDiskSpace(path string) (uint64, error) {
 
 	// Available blocks * size per block = available space in bytes
 	var bavail = stat.Bavail
+	// nolint:staticcheck
 	if stat.Bavail < 0 {
 		// FreeBSD can have a negative number of blocks available
 		// because of the grace limit.