build: remove random.Seed since random generator is seeded automatically in go1.20

Now that the minimum version is go1.20 we can stop seeding the random
number generator.

cmd/cmd.go

@@ -39,7 +39,6 @@ import (
 	"github.com/rclone/rclone/lib/atexit"
 	"github.com/rclone/rclone/lib/buildinfo"
 	"github.com/rclone/rclone/lib/exitcode"
-	"github.com/rclone/rclone/lib/random"
 	"github.com/rclone/rclone/lib/terminal"
 	"github.com/spf13/cobra"
 	"github.com/spf13/pflag"
@@ -562,9 +561,6 @@ func AddBackendFlags() {
 
 // Main runs rclone interpreting flags and commands out of os.Args
 func Main() {
-	if err := random.Seed(); err != nil {
-		log.Fatalf("Fatal error: %v", err)
-	}
 	setupRootCommand(Root)
 	AddBackendFlags()
 	if err := Root.Execute(); err != nil {

fstest/fstest.go

@@ -49,11 +49,6 @@ var (
 	MatchTestRemote = regexp.MustCompile(`^rclone-test-[abcdefghijklmnopqrstuvwxyz0123456789]{24}$`)
 )
 
-// Seed the random number generator
-func init() {
-	_ = random.Seed()
-}
-
 // Initialise rclone for testing
 func Initialise() {
 	ctx := context.Background()

lib/random/random_seed.go

@@ -1,17 +0,0 @@
-//go:build go1.20
-
-package random
-
-// Seed the global math/rand with crypto strong data
-//
-// This doesn't make it OK to use math/rand in crypto sensitive
-// environments - don't do that! However it does help to mitigate the
-// problem if that happens accidentally. This would have helped with
-// CVE-2020-28924 - #4783
-//
-// As of Go 1.20 there is no reason to call math/rand.Seed with a
-// random value as it is self seeded to a random 64 bit number so this
-// does nothing.
-func Seed() error {
-	return nil
-}

lib/random/random_seed_old.go

@@ -1,29 +0,0 @@
-//go:build !go1.20
-
-package random
-
-import (
-	cryptorand "crypto/rand"
-	"encoding/binary"
-	"fmt"
-	mathrand "math/rand"
-)
-
-// Seed the global math/rand with crypto strong data
-//
-// This doesn't make it OK to use math/rand in crypto sensitive
-// environments - don't do that! However it does help to mitigate the
-// problem if that happens accidentally. This would have helped with
-// CVE-2020-28924 - #4783
-//
-// As of Go 1.20 there is no reason to call math/rand.Seed with a
-// random value as it is self seeded to a random 64 bit number.
-func Seed() error {
-	var seed int64
-	err := binary.Read(cryptorand.Reader, binary.LittleEndian, &seed)
-	if err != nil {
-		return fmt.Errorf("failed to read random seed: %w", err)
-	}
-	mathrand.Seed(seed)
-	return nil
-}

lib/random/random_test.go

@@ -1,7 +1,6 @@
 package random
 
 import (
-	"math/rand"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -49,16 +48,3 @@ func TestPasswordDuplicates(t *testing.T) {
 		seen[s] = true
 	}
 }
-
-func TestSeed(t *testing.T) {
-	// seed 100 times and check the first random number doesn't repeat
-	// This test could fail with a probability of ~ 10**-15
-	const n = 100
-	var seen = map[int64]bool{}
-	for i := 0; i < n; i++ {
-		assert.NoError(t, Seed())
-		first := rand.Int63()
-		assert.False(t, seen[first])
-		seen[first] = true
-	}
-}

vfs/test_vfs/test_vfs.go

@@ -29,12 +29,6 @@ var (
 	testNumber atomic.Int32
 )
 
-// Seed the random number generator
-func init() {
-	_ = random.Seed()
-
-}
-
 // Test contains stats about the running test which work for files or
 // directories
 type Test struct {