*: stop using math/rand

Mostly this switches to math/rand/v2, but sometimes randomness is not really needed.

Signed-off-by: Roman Khimov <roman@nspcc.ru>

internal/random/random_util.go

@@ -1,8 +1,7 @@
 package random
 
 import (
-	"math/rand"
-	"time"
+	"math/rand/v2"
 
 	"github.com/nspcc-dev/neo-go/pkg/crypto/hash"
 	"github.com/nspcc-dev/neo-go/pkg/util"
@@ -27,14 +26,14 @@ func Bytes(n int) []byte {
 
 // Fill fills buffer with random bytes.
 func Fill(buf []byte) {
-	r := rand.New(rand.NewSource(time.Now().UnixNano()))
-	// Rand reader returns no errors
-	r.Read(buf)
+	for i := range buf {
+		buf[i] = byte(rand.Int())
+	}
 }
 
 // Int returns a random integer in [minI,maxI).
 func Int(minI, maxI int) int {
-	return minI + rand.Intn(maxI-minI)
+	return minI + rand.IntN(maxI-minI)
 }
 
 // Uint256 returns a random Uint256.
@@ -48,8 +47,3 @@ func Uint160() util.Uint160 {
 	str := String(20)
 	return hash.RipeMD160([]byte(str))
 }
-
-func init() {
-	//nolint:staticcheck
-	rand.Seed(time.Now().UTC().UnixNano())
-}

pkg/consensus/payload_test.go

@@ -3,7 +3,7 @@ package consensus
 import (
 	"encoding/hex"
 	gio "io"
-	"math/rand"
+	"math/rand/v2"
 	"testing"
 
 	"github.com/nspcc-dev/dbft"

pkg/core/interop/runtime/engine_test.go

@@ -3,7 +3,6 @@ package runtime
 import (
 	"encoding/json"
 	"math/big"
-	"math/rand"
 	"testing"
 
 	"github.com/nspcc-dev/neo-go/internal/random"
@@ -46,10 +45,10 @@ func TestPlatform(t *testing.T) {
 
 func TestGetTime(t *testing.T) {
 	b := block.New(false)
-	b.Timestamp = rand.Uint64()
+	b.Timestamp = 1725021259
 	ic := &interop.Context{VM: vm.New(), Block: b}
 	require.NoError(t, GetTime(ic))
-	checkStack(t, ic.VM, new(big.Int).SetUint64(b.Timestamp))
+	checkStack(t, ic.VM, new(big.Int).SetUint64(1725021259))
 }
 
 func TestGetScriptHash(t *testing.T) {

pkg/core/state/mpt_root_test.go

@@ -2,7 +2,7 @@ package state
 
 import (
 	"encoding/json"
-	"math/rand"
+	"math/rand/v2"
 	"testing"
 
 	"github.com/nspcc-dev/neo-go/internal/random"

pkg/core/state/tokens_test.go

@@ -2,9 +2,8 @@ package state
 
 import (
 	"math/big"
-	"math/rand"
+	"math/rand/v2"
 	"testing"
-	"time"
 
 	"github.com/nspcc-dev/neo-go/internal/random"
 	"github.com/nspcc-dev/neo-go/internal/testserdes"
@@ -13,7 +12,7 @@ import (
 )
 
 func TestTokenTransferLog_Append17(t *testing.T) {
-	r := rand.New(rand.NewSource(time.Now().UnixNano()))
+	r := rand.New(rand.NewPCG(42, 100500))
 	expected := []*NEP17Transfer{
 		random17Transfer(r),
 		random17Transfer(r),
@@ -39,7 +38,7 @@ func TestTokenTransferLog_Append17(t *testing.T) {
 }
 
 func TestTokenTransferLog_Append(t *testing.T) {
-	r := rand.New(rand.NewSource(time.Now().UnixNano()))
+	r := rand.New(rand.NewPCG(42, 100500))
 	expected := []*NEP11Transfer{
 		random11Transfer(r),
 		random11Transfer(r),
@@ -65,7 +64,7 @@ func TestTokenTransferLog_Append(t *testing.T) {
 }
 
 func BenchmarkTokenTransferLog_Append(b *testing.B) {
-	r := rand.New(rand.NewSource(time.Now().UnixNano()))
+	r := rand.New(rand.NewPCG(42, 100500))
 	ts := make([]*NEP17Transfer, TokenTransferBatchSize)
 	for i := range ts {
 		ts[i] = random17Transfer(r)

pkg/core/transaction/oracle_test.go

@@ -2,7 +2,7 @@ package transaction
 
 import (
 	"encoding/json"
-	"math/rand"
+	"math/rand/v2"
 	"testing"
 
 	"github.com/nspcc-dev/neo-go/internal/testserdes"

pkg/core/transaction/transaction.go

@@ -8,7 +8,7 @@ import (
 	"fmt"
 	"math"
 	"math/big"
-	"math/rand"
+	"math/rand/v2"
 
 	"github.com/nspcc-dev/neo-go/pkg/crypto/hash"
 	"github.com/nspcc-dev/neo-go/pkg/encoding/address"

pkg/crypto/hash/merkle_bench_test.go

@@ -1,29 +1,24 @@
-package hash
+package hash_test
 
 import (
-	"math/rand"
 	"testing"
-	"time"
 
+	"github.com/nspcc-dev/neo-go/internal/random"
+	"github.com/nspcc-dev/neo-go/pkg/crypto/hash"
 	"github.com/nspcc-dev/neo-go/pkg/util"
 	"github.com/stretchr/testify/require"
 )
 
 func BenchmarkMerkle(t *testing.B) {
-	var err error
 	var hashes = make([]util.Uint256, 100000)
-	var h = make([]byte, 32)
-	r := rand.New(rand.NewSource(time.Now().UnixNano()))
 	for i := range hashes {
-		r.Read(h)
-		hashes[i], err = util.Uint256DecodeBytesBE(h)
-		require.NoError(t, err)
+		hashes[i] = random.Uint256()
 	}
 
 	t.Run("NewMerkleTree", func(t *testing.B) {
 		t.ResetTimer()
 		for n := 0; n < t.N; n++ {
-			tr, err := NewMerkleTree(hashes)
+			tr, err := hash.NewMerkleTree(hashes)
 			require.NoError(t, err)
 			_ = tr.Root()
 		}
@@ -31,7 +26,7 @@ func BenchmarkMerkle(t *testing.B) {
 	t.Run("CalcMerkleRoot", func(t *testing.B) {
 		t.ResetTimer()
 		for n := 0; n < t.N; n++ {
-			_ = CalcMerkleRoot(hashes)
+			_ = hash.CalcMerkleRoot(hashes)
 		}
 	})
 }

pkg/network/discovery.go

@@ -2,7 +2,7 @@ package network
 
 import (
 	"math"
-	"math/rand"
+	"math/rand/v2"
 	"sync"
 	"sync/atomic"
 	"time"
@@ -300,7 +300,7 @@ func (d *DefaultDiscovery) updateNetSize() {
 }
 
 func (d *DefaultDiscovery) tryAddress(addr string) {
-	var tout = rand.Int63n(int64(tryMaxWait))
+	var tout = rand.Int64N(int64(tryMaxWait))
 	time.Sleep(time.Duration(tout)) // Have a sleep before working hard.
 	p, err := d.transport.Dial(addr, d.dialTimeout)
 	atomic.AddInt32(&d.outstanding, -1)

pkg/network/fuzz_test.go

@@ -1,18 +1,18 @@
 package network
 
 import (
-	"math/rand"
+	"math/rand/v2"
 	"testing"
 
+	"github.com/nspcc-dev/neo-go/internal/random"
 	"github.com/nspcc-dev/neo-go/pkg/io"
 	"github.com/stretchr/testify/require"
 )
 
 func FuzzMessageDecode(f *testing.F) {
 	for i := 0; i < 100; i++ {
-		seed := make([]byte, rand.Uint32()%1000)
-		//nolint:staticcheck
-		rand.Read(seed)
+		seed := make([]byte, rand.IntN(1000))
+		random.Fill(seed)
 		f.Add(seed)
 	}
 

pkg/network/message_test.go

@@ -2,7 +2,7 @@ package network
 
 import (
 	"errors"
-	"math/rand"
+	"math/rand/v2"
 	"testing"
 	"time"
 

pkg/network/server.go

@@ -7,7 +7,7 @@ import (
 	"errors"
 	"fmt"
 	"math/big"
-	mrand "math/rand"
+	mrand "math/rand/v2"
 	"net"
 	"runtime"
 	"slices"
@@ -1331,7 +1331,7 @@ func getRequestBlocksPayload(p Peer, currHeight uint32, lastRequestedHeight *ato
 				}
 			}
 		} else {
-			index := mrand.Intn(bqueue.CacheSize / payload.MaxHashesCount)
+			index := mrand.IntN(bqueue.CacheSize / payload.MaxHashesCount)
 			needHeight = currHeight + 1 + uint32(index*payload.MaxHashesCount)
 		}
 		break

pkg/services/notary/core_test.go

@@ -4,7 +4,7 @@ import (
 	"errors"
 	"fmt"
 	"math/big"
-	"math/rand"
+	"math/rand/v2"
 	"sync"
 	"testing"
 	"time"

pkg/vm/vm_test.go

@@ -8,7 +8,7 @@ import (
 	"fmt"
 	"math"
 	"math/big"
-	"math/rand"
+	"math/rand/v2"
 	"strings"
 	"testing"
 
@@ -2842,7 +2842,7 @@ func randomBytes(n int) []byte {
 	const charset = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
 	b := make([]byte, n)
 	for i := range b {
-		b[i] = charset[rand.Intn(len(charset))]
+		b[i] = charset[rand.IntN(len(charset))]
 	}
 	return b
 }