Fix a bunch of staticcheck errors

Tool-assisted.

24 files changed, 99 insertions, 119 deletions

diff --git a/tests/cli/cli_test.go b/tests/cli/cli_test.go
index fb09338..01cc3b7 100644
--- a/tests/cli/cli_test.go
+++ b/tests/cli/cli_test.go
@@ -6,7 +6,6 @@ import (
 	"encoding/hex"
 	"errors"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"strconv"
@@ -174,7 +173,7 @@ func TestPasswd(t *testing.T) {
 	// Add content
 	test_helpers.MountOrFatal(t, dir, mnt, "-extpass", "echo test")
 	file1 := mnt + "/file1"
-	err := ioutil.WriteFile(file1, []byte("somecontent"), 0600)
+	err := os.WriteFile(file1, []byte("somecontent"), 0600)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -186,7 +185,7 @@ func TestPasswd(t *testing.T) {
 	testPasswd(t, dir)
 	// Mount and verify
 	test_helpers.MountOrFatal(t, dir, mnt, "-extpass", "echo newpasswd")
-	content, err := ioutil.ReadFile(file1)
+	content, err := os.ReadFile(file1)
 	if err != nil {
 		t.Error(err)
 	} else if string(content) != "somecontent" {
@@ -201,12 +200,12 @@ func TestPasswd(t *testing.T) {
 // cp copies file at `src` to `dst`, overwriting
 // `dst` if it already exists. Calls t.Fatal on failure.
 func cp(t *testing.T, src string, dst string) {
-	conf, err := ioutil.ReadFile(src)
+	conf, err := os.ReadFile(src)
 	if err != nil {
 		t.Fatal(err)
 	}
 	syscall.Unlink(dst)
-	err = ioutil.WriteFile(dst, conf, 0600)
+	err = os.WriteFile(dst, conf, 0600)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -222,7 +221,7 @@ func TestPasswdMasterkey(t *testing.T) {
 	mnt := dir + ".mnt"
 	test_helpers.MountOrFatal(t, dir, mnt, "-extpass", "echo test")
 	file1 := mnt + "/file1"
-	err := ioutil.WriteFile(file1, []byte("somecontent"), 0600)
+	err := os.WriteFile(file1, []byte("somecontent"), 0600)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -251,7 +250,7 @@ func TestPasswdMasterkey(t *testing.T) {
 	}
 	// Mount and verify
 	test_helpers.MountOrFatal(t, dir, mnt, "-extpass", "echo newpasswd")
-	content, err := ioutil.ReadFile(file1)
+	content, err := os.ReadFile(file1)
 	if err != nil {
 		t.Error(err)
 	} else if string(content) != "somecontent" {
@@ -270,7 +269,7 @@ func TestPasswdMasterkeyStdin(t *testing.T) {
 	mnt := dir + ".mnt"
 	test_helpers.MountOrFatal(t, dir, mnt, "-extpass", "echo test")
 	file1 := mnt + "/file1"
-	err := ioutil.WriteFile(file1, []byte("somecontent"), 0600)
+	err := os.WriteFile(file1, []byte("somecontent"), 0600)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -300,7 +299,7 @@ func TestPasswdMasterkeyStdin(t *testing.T) {
 	}
 	// Mount and verify
 	test_helpers.MountOrFatal(t, dir, mnt, "-extpass", "echo newpasswd")
-	content, err := ioutil.ReadFile(file1)
+	content, err := os.ReadFile(file1)
 	if err != nil {
 		t.Fatal(err)
 	} else if string(content) != "somecontent" {
@@ -392,7 +391,7 @@ func TestNonempty(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	err = ioutil.WriteFile(mnt+"/somefile", []byte("xyz"), 0600)
+	err = os.WriteFile(mnt+"/somefile", []byte("xyz"), 0600)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -586,7 +585,7 @@ func TestNoexec(t *testing.T) {
 	content := `#!/bin/bash
 echo hello
 `
-	err := ioutil.WriteFile(sh, []byte(content), 0755)
+	err := os.WriteFile(sh, []byte(content), 0755)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -697,13 +696,13 @@ func TestNotIdle(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	err = ioutil.WriteFile(mnt+"/foo", []byte("foo"), 0600)
+	err = os.WriteFile(mnt+"/foo", []byte("foo"), 0600)
 	if err != nil {
 		t.Fatal(err)
 	}
 	// Read every 10 milliseconds for a total of 1 second
 	for i := 1; i < 100; i++ {
-		_, err = ioutil.ReadFile(mnt + "/foo")
+		_, err = os.ReadFile(mnt + "/foo")
 		if err != nil {
 			t.Fatalf("iteration %d failed: %v", i, err)
 		}
@@ -784,7 +783,7 @@ func TestBadname(t *testing.T) {
 
 	file := mnt + "/" + validFileName
 	// Case 1: write one valid filename (empty content)
-	err := ioutil.WriteFile(file, nil, 0600)
+	err := os.WriteFile(file, nil, 0600)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -809,26 +808,26 @@ func TestBadname(t *testing.T) {
 	}
 	//Generate valid cipherdata for all cases
 	for i := 0; i < len(contentCipher); i++ {
-		err := ioutil.WriteFile(file, []byte(fmt.Sprintf("Content Case %d.", i+1)), 0600)
+		err := os.WriteFile(file, []byte(fmt.Sprintf("Content Case %d.", i+1)), 0600)
 		if err != nil {
 			t.Fatal(err)
 		}
 		//save the cipher data for file operations in cipher dir
-		contentCipher[i], err = ioutil.ReadFile(dir + "/" + encryptedfilename)
+		contentCipher[i], err = os.ReadFile(dir + "/" + encryptedfilename)
 		if err != nil {
 			t.Fatal(err)
 		}
 	}
 
 	//re-write content for case 1
-	err = ioutil.WriteFile(file, []byte("Content Case 1."), 0600)
+	err = os.WriteFile(file, []byte("Content Case 1."), 0600)
 	if err != nil {
 		t.Fatal(err)
 	}
 
 	// Case 2: File with invalid suffix in plain name but valid cipher file
 	file = mnt + "/" + validFileName + nametransform.BadnameSuffix
-	err = ioutil.WriteFile(file, []byte("Content Case 2."), 0600)
+	err = os.WriteFile(file, []byte("Content Case 2."), 0600)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -842,29 +841,29 @@ func TestBadname(t *testing.T) {
 	// Case 3 is impossible: only BadnameSuffix would mean the cipher name is valid
 
 	// Case 4: write invalid file which should be decodable
-	err = ioutil.WriteFile(dir+"/"+encryptedfilename+invalidSuffix, contentCipher[3], 0600)
+	err = os.WriteFile(dir+"/"+encryptedfilename+invalidSuffix, contentCipher[3], 0600)
 	if err != nil {
 		t.Fatal(err)
 	}
 	//Case 5: write invalid file which is not decodable (replace last 2 bytes with percent sign)
-	err = ioutil.WriteFile(dir+"/"+encryptedfilename[:len(encryptedfilename)-2]+"%%"+invalidSuffix, contentCipher[4], 0600)
+	err = os.WriteFile(dir+"/"+encryptedfilename[:len(encryptedfilename)-2]+"%%"+invalidSuffix, contentCipher[4], 0600)
 	if err != nil {
 		t.Fatal(err)
 	}
 
 	// Case 6: Multiple possible matches
 	// generate two files with invalid cipher names which can both match the badname pattern
-	err = ioutil.WriteFile(dir+"/mzaZRF9_0IU-_5vv2wPC"+invalidSuffix, contentCipher[5], 0600)
+	err = os.WriteFile(dir+"/mzaZRF9_0IU-_5vv2wPC"+invalidSuffix, contentCipher[5], 0600)
 	if err != nil {
 		t.Fatal(err)
 	}
-	err = ioutil.WriteFile(dir+"/mzaZRF9_0IU-_5vv2wP"+invalidSuffix, contentCipher[5], 0600)
+	err = os.WriteFile(dir+"/mzaZRF9_0IU-_5vv2wP"+invalidSuffix, contentCipher[5], 0600)
 	if err != nil {
 		t.Fatal(err)
 	}
 
 	// Case 7: Non-Matching badname pattern
-	err = ioutil.WriteFile(dir+"/"+encryptedfilename+"wrongPattern", contentCipher[6], 0600)
+	err = os.WriteFile(dir+"/"+encryptedfilename+"wrongPattern", contentCipher[6], 0600)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -894,7 +893,7 @@ func TestBadname(t *testing.T) {
 	for _, name := range names {
 		if name == searchstrings[0] {
 			//Case 1: Test access
-			filebytes, err = ioutil.ReadFile(mnt + "/" + name)
+			filebytes, err = os.ReadFile(mnt + "/" + name)
 			if err != nil {
 				t.Fatal(err)
 			}
@@ -905,7 +904,7 @@ func TestBadname(t *testing.T) {
 
 		} else if name == searchstrings[1] {
 			//Case 2: Test Access
-			filebytes, err = ioutil.ReadFile(mnt + "/" + name)
+			filebytes, err = os.ReadFile(mnt + "/" + name)
 			if err != nil {
 				t.Fatal(err)
 			}
@@ -915,7 +914,7 @@ func TestBadname(t *testing.T) {
 			}
 		} else if name == searchstrings[3] {
 			//Case 4: Test Access
-			filebytes, err = ioutil.ReadFile(mnt + "/" + name)
+			filebytes, err = os.ReadFile(mnt + "/" + name)
 			if err != nil {
 				t.Fatal(err)
 			}
@@ -925,7 +924,7 @@ func TestBadname(t *testing.T) {
 			}
 		} else if name == searchstrings[4] {
 			//Case 5: Test Access
-			filebytes, err = ioutil.ReadFile(mnt + "/" + name)
+			filebytes, err = os.ReadFile(mnt + "/" + name)
 			if err != nil {
 				t.Fatal(err)
 			}
@@ -955,7 +954,7 @@ func TestPassfile(t *testing.T) {
 	dir := test_helpers.InitFS(t)
 	mnt := dir + ".mnt"
 	passfile1 := mnt + ".1.txt"
-	ioutil.WriteFile(passfile1, []byte("test"), 0600)
+	os.WriteFile(passfile1, []byte("test"), 0600)
 	test_helpers.MountOrFatal(t, dir, mnt, "-passfile="+passfile1)
 	defer test_helpers.UnmountPanic(mnt)
 }
@@ -966,8 +965,8 @@ func TestPassfileX2(t *testing.T) {
 	mnt := dir + ".mnt"
 	passfile1 := mnt + ".1.txt"
 	passfile2 := mnt + ".2.txt"
-	ioutil.WriteFile(passfile1, []byte("te"), 0600)
-	ioutil.WriteFile(passfile2, []byte("st"), 0600)
+	os.WriteFile(passfile1, []byte("te"), 0600)
+	os.WriteFile(passfile2, []byte("st"), 0600)
 	test_helpers.MountOrFatal(t, dir, mnt, "-passfile="+passfile1, "-passfile="+passfile2)
 	defer test_helpers.UnmountPanic(mnt)
 }
@@ -979,7 +978,7 @@ func TestInitNotEmpty(t *testing.T) {
 	if err := os.Mkdir(dir, 0700); err != nil {
 		t.Fatal(err)
 	}
-	if err := ioutil.WriteFile(dir+"/foo", nil, 0700); err != nil {
+	if err := os.WriteFile(dir+"/foo", nil, 0700); err != nil {
 		t.Fatal(err)
 	}
 	cmd := exec.Command(test_helpers.GocryptfsBinary, "-init", "-extpass", "echo test", dir)
@@ -1001,7 +1000,7 @@ func TestSharedstorage(t *testing.T) {
 	defer test_helpers.UnmountPanic(mnt)
 	foo1 := mnt + "/foo1"
 	foo2 := mnt + "/foo2"
-	if err := ioutil.WriteFile(foo1, nil, 0755); err != nil {
+	if err := os.WriteFile(foo1, nil, 0755); err != nil {
 		t.Fatal(err)
 	}
 	if err := os.Link(foo1, foo2); err != nil {
@@ -1020,7 +1019,7 @@ func TestSharedstorage(t *testing.T) {
 	}
 	// Check that we we don't have stat caching. New length should show up
 	// on the hard link immediately.
-	if err := ioutil.WriteFile(foo1, []byte("xxxxxx"), 0755); err != nil {
+	if err := os.WriteFile(foo1, []byte("xxxxxx"), 0755); err != nil {
 		t.Fatal(err)
 	}
 	if err := syscall.Stat(foo2, &st2); err != nil {
diff --git a/tests/cli/longnamemax_test.go b/tests/cli/longnamemax_test.go
index e44a84e..357ede6 100644
--- a/tests/cli/longnamemax_test.go
+++ b/tests/cli/longnamemax_test.go
@@ -2,7 +2,6 @@ package cli
 
 import (
 	"fmt"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strings"
@@ -38,7 +37,7 @@ func TestLongnamemax100(t *testing.T) {
 
 	for l := 1; l <= 255; l++ {
 		path := pDir + "/" + strings.Repeat("x", l)
-		if err := ioutil.WriteFile(path, nil, 0600); err != nil {
+		if err := os.WriteFile(path, nil, 0600); err != nil {
 			t.Fatal(err)
 		}
 		matches, err := filepath.Glob(cDir + "/gocryptfs.longname.*")
@@ -84,7 +83,7 @@ func TestLongnamemax100Reverse(t *testing.T) {
 
 	for l := 1; l <= 255; l++ {
 		path := backingDir + "/" + strings.Repeat("x", l)
-		if err := ioutil.WriteFile(path, nil, 0600); err != nil {
+		if err := os.WriteFile(path, nil, 0600); err != nil {
 			t.Fatal(err)
 		}
 		matches, err := filepath.Glob(mntDir + "/gocryptfs.longname.*")
diff --git a/tests/cli/xchacha_test.go b/tests/cli/xchacha_test.go
index 7f24c8b..f0fe163 100644
--- a/tests/cli/xchacha_test.go
+++ b/tests/cli/xchacha_test.go
@@ -2,7 +2,6 @@ package cli
 
 import (
 	"fmt"
-	"io/ioutil"
 	"os"
 	"syscall"
 	"testing"
@@ -40,7 +39,7 @@ func TestXchacha(t *testing.T) {
 	test_helpers.MountOrExit(cDir, pDir, "-extpass", "echo test")
 	defer test_helpers.UnmountPanic(pDir)
 
-	if err := ioutil.WriteFile(pDir+"/1byte", []byte("x"), 0700); err != nil {
+	if err := os.WriteFile(pDir+"/1byte", []byte("x"), 0700); err != nil {
 		t.Fatal(err)
 	}
 	var st syscall.Stat_t
@@ -53,7 +52,7 @@ func TestXchacha(t *testing.T) {
 	}
 
 	// 1 MiB = 256 4kiB blocks
-	if err := ioutil.WriteFile(pDir+"/1MiB", make([]byte, 1024*1024), 0700); err != nil {
+	if err := os.WriteFile(pDir+"/1MiB", make([]byte, 1024*1024), 0700); err != nil {
 		t.Fatal(err)
 	}
 	if err := syscall.Stat(cDir+"/1MiB", &st); err != nil {
diff --git a/tests/cli/zerokey_test.go b/tests/cli/zerokey_test.go
index e9b9c50..359651c 100644
--- a/tests/cli/zerokey_test.go
+++ b/tests/cli/zerokey_test.go
@@ -1,7 +1,6 @@
 package cli
 
 import (
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"testing"
@@ -42,7 +41,7 @@ func TestZerokey(t *testing.T) {
 	mnt := dir + ".mnt"
 	test_helpers.MountOrFatal(t, dir, mnt, "-extpass", "echo test")
 	file1 := mnt + "/file1"
-	err = ioutil.WriteFile(file1, []byte("somecontent"), 0600)
+	err = os.WriteFile(file1, []byte("somecontent"), 0600)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -50,7 +49,7 @@ func TestZerokey(t *testing.T) {
 
 	// Mount using -zerokey and verify we get the same result
 	test_helpers.MountOrFatal(t, dir, mnt, "-extpass", "echo test")
-	content, err := ioutil.ReadFile(file1)
+	content, err := os.ReadFile(file1)
 	if err != nil {
 		t.Error(err)
 	} else if string(content) != "somecontent" {
diff --git a/tests/defaults/acl_test.go b/tests/defaults/acl_test.go
index 2ab5dc1..0dae018 100644
--- a/tests/defaults/acl_test.go
+++ b/tests/defaults/acl_test.go
@@ -1,7 +1,6 @@
 package defaults
 
 import (
-	"io/ioutil"
 	"math/rand"
 	"os"
 	"os/exec"
@@ -35,7 +34,7 @@ func TestCpA(t *testing.T) {
 		var modeWant os.FileMode = os.FileMode(rand.Int31n(0777+1) | 0400)
 
 		// Create file outside mount
-		err := ioutil.WriteFile(fn1, nil, modeWant)
+		err := os.WriteFile(fn1, nil, modeWant)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -45,7 +44,7 @@ func TestCpA(t *testing.T) {
 			t.Fatal(err)
 		}
 		if fi.Mode() != modeWant {
-			t.Errorf("ioutil.WriteFile created wrong permissions: want %o have %o", modeWant, fi.Mode())
+			t.Errorf("os.WriteFile created wrong permissions: want %o have %o", modeWant, fi.Mode())
 		}
 
 		// "cp -a" from outside to inside mount
@@ -93,7 +92,7 @@ func TestAcl543(t *testing.T) {
 	}
 
 	// Set acl on file outside gocryptfs mount
-	err := ioutil.WriteFile(fn1, nil, modeWant)
+	err := os.WriteFile(fn1, nil, modeWant)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -117,7 +116,7 @@ func TestAcl543(t *testing.T) {
 	}
 
 	// Set acl on file inside gocryptfs mount
-	err = ioutil.WriteFile(fn2, nil, modeWant)
+	err = os.WriteFile(fn2, nil, modeWant)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -164,7 +163,7 @@ func TestAcl543(t *testing.T) {
 // Check that we handle zero-sized and undersized buffers correctly
 func TestXattrOverflow(t *testing.T) {
 	fn := filepath.Join(test_helpers.DefaultPlainDir, t.Name())
-	ioutil.WriteFile(fn, nil, 0600)
+	os.WriteFile(fn, nil, 0600)
 
 	attr := "user.foo123"
 	val := []byte("12341234")
diff --git a/tests/defaults/diriv_test.go b/tests/defaults/diriv_test.go
index 639b33d..48ba39a 100644
--- a/tests/defaults/diriv_test.go
+++ b/tests/defaults/diriv_test.go
@@ -1,7 +1,6 @@
 package defaults
 
 import (
-	"io/ioutil"
 	"os"
 	"sync"
 	"sync/atomic"
@@ -19,7 +18,7 @@ func TestDirIVRace(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	err = ioutil.WriteFile(dir1+"/file", nil, 0600)
+	err = os.WriteFile(dir1+"/file", nil, 0600)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -31,7 +30,7 @@ func TestDirIVRace(t *testing.T) {
 		t.Fatal(err)
 	}
 	file2 := dir2 + "/file"
-	err = ioutil.WriteFile(file2, nil, 0600)
+	err = os.WriteFile(file2, nil, 0600)
 	if err != nil {
 		t.Fatal(err)
 	}
diff --git a/tests/defaults/main_test.go b/tests/defaults/main_test.go
index 75a5dae..a19f079 100644
--- a/tests/defaults/main_test.go
+++ b/tests/defaults/main_test.go
@@ -5,7 +5,6 @@ import (
 	"bytes"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -176,7 +175,7 @@ func TestXfs124(t *testing.T) {
 
 func TestWrite0200File(t *testing.T) {
 	fn := test_helpers.DefaultPlainDir + "/TestWrite0200File"
-	err := ioutil.WriteFile(fn, nil, 0200)
+	err := os.WriteFile(fn, nil, 0200)
 	if err != nil {
 		t.Fatalf("creating empty file failed: %v", err)
 	}
@@ -212,7 +211,7 @@ func TestWrite0200File(t *testing.T) {
 // Now we return EOPNOTSUPP and mv is happy.
 func TestMvWarnings(t *testing.T) {
 	fn := test_helpers.TmpDir + "/TestMvWarnings"
-	err := ioutil.WriteFile(fn, nil, 0600)
+	err := os.WriteFile(fn, nil, 0600)
 	if err != nil {
 		t.Fatalf("creating file failed: %v", err)
 	}
@@ -257,7 +256,7 @@ func TestMvWarningSymlink(t *testing.T) {
 // See TestMvWarnings.
 func TestCpWarnings(t *testing.T) {
 	fn := test_helpers.TmpDir + "/TestCpWarnings"
-	err := ioutil.WriteFile(fn, []byte("foo"), 0600)
+	err := os.WriteFile(fn, []byte("foo"), 0600)
 	if err != nil {
 		t.Fatalf("creating file failed: %v", err)
 	}
diff --git a/tests/defaults/overlayfs_test.go b/tests/defaults/overlayfs_test.go
index 8cb773d..2b374b1 100644
--- a/tests/defaults/overlayfs_test.go
+++ b/tests/defaults/overlayfs_test.go
@@ -4,7 +4,6 @@
 package defaults
 
 import (
-	"io/ioutil"
 	"os"
 	"strings"
 	"testing"
@@ -43,7 +42,7 @@ func TestRenameWhiteout(t *testing.T) {
 		for _, n := range names {
 			pSrc := test_helpers.DefaultPlainDir + "/" + n[0]
 			pDst := test_helpers.DefaultPlainDir + "/" + n[1]
-			if err := ioutil.WriteFile(pSrc, nil, 0200); err != nil {
+			if err := os.WriteFile(pSrc, nil, 0200); err != nil {
 				t.Fatalf("creating empty file failed: %v", err)
 			}
 			err := unix.Renameat2(-1, pSrc, -1, pDst, flags)
@@ -96,10 +95,10 @@ func TestRenameExchange(t *testing.T) {
 	for _, n := range names {
 		pSrc := test_helpers.DefaultPlainDir + "/" + n[0]
 		pDst := test_helpers.DefaultPlainDir + "/" + n[1]
-		if err := ioutil.WriteFile(pSrc, nil, 0200); err != nil {
+		if err := os.WriteFile(pSrc, nil, 0200); err != nil {
 			t.Fatalf("creating empty file failed: %v", err)
 		}
-		if err := ioutil.WriteFile(pDst, nil, 0200); err != nil {
+		if err := os.WriteFile(pDst, nil, 0200); err != nil {
 			t.Fatalf("creating empty file failed: %v", err)
 		}
 		err := unix.Renameat2(-1, pSrc, -1, pDst, unix.RENAME_EXCHANGE)
diff --git a/tests/defaults/performance_test.go b/tests/defaults/performance_test.go
index 11d827f..8bae5c1 100644
--- a/tests/defaults/performance_test.go
+++ b/tests/defaults/performance_test.go
@@ -4,7 +4,6 @@ package defaults
 import (
 	"fmt"
 	"io"
-	"io/ioutil"
 	"os"
 	"testing"
 
@@ -96,7 +95,7 @@ func createFiles(t *testing.B, count int, size int) {
 	for i = 0; i < count; i++ {
 		file := fmt.Sprintf("%s/%d", dir, i)
 		if size > 0 {
-			err = ioutil.WriteFile(file, buf, 0666)
+			err = os.WriteFile(file, buf, 0666)
 		} else {
 			var fh *os.File
 			fh, err = os.Create(file)
diff --git a/tests/deterministic_names/deterministic_names_test.go b/tests/deterministic_names/deterministic_names_test.go
index 00d80fc..330cfc3 100644
--- a/tests/deterministic_names/deterministic_names_test.go
+++ b/tests/deterministic_names/deterministic_names_test.go
@@ -4,7 +4,6 @@ package deterministic_names
 
 import (
 	"fmt"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"testing"
@@ -70,7 +69,7 @@ func TestDeterministicNames(t *testing.T) {
 	if err := os.RemoveAll(pDir + "/foo"); err != nil {
 		t.Fatal(err)
 	}
-	if err := ioutil.WriteFile(pDir+"/foo", nil, 0700); err != nil {
+	if err := os.WriteFile(pDir+"/foo", nil, 0700); err != nil {
 		t.Fatal(err)
 	}
 	_, err = os.Stat(cDir + "/" + fooEncrypted)
diff --git a/tests/example_filesystems/example_test_helpers.go b/tests/example_filesystems/example_test_helpers.go
index c56d75a..34e5786 100644
--- a/tests/example_filesystems/example_test_helpers.go
+++ b/tests/example_filesystems/example_test_helpers.go
@@ -1,7 +1,6 @@
 package example_filesystems
 
 import (
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"testing"
@@ -15,7 +14,7 @@ const statusTxtContent = "It works!\n"
 func checkExampleFS(t *testing.T, dir string, rw bool) {
 	// Read regular file
 	statusFile := filepath.Join(dir, "status.txt")
-	contentBytes, err := ioutil.ReadFile(statusFile)
+	contentBytes, err := os.ReadFile(statusFile)
 	if err != nil {
 		t.Error(err)
 		return
@@ -68,7 +67,7 @@ func checkExampleFSrw(t *testing.T, dir string, rw bool) {
 		"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx" +
 		"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx" +
 		"xxxxxxxxxxxxxxxxxxxxxxxx"
-	contentBytes, err := ioutil.ReadFile(filepath.Join(dir, longname))
+	contentBytes, err := os.ReadFile(filepath.Join(dir, longname))
 	if err != nil {
 		t.Error(err)
 		return
diff --git a/tests/hkdf_sanity/sanity_test.go b/tests/hkdf_sanity/sanity_test.go
index f221439..27a1085 100644
--- a/tests/hkdf_sanity/sanity_test.go
+++ b/tests/hkdf_sanity/sanity_test.go
@@ -4,7 +4,6 @@
 package hkdf_sanity
 
 import (
-	"io/ioutil"
 	"os"
 	"testing"
 
@@ -15,7 +14,7 @@ func TestBrokenContent(t *testing.T) {
 	cDir := "broken_content"
 	pDir := test_helpers.TmpDir + "/" + cDir
 	test_helpers.MountOrFatal(t, cDir, pDir, "-extpass", "echo test", "-wpanic=false")
-	_, err := ioutil.ReadFile(pDir + "/status.txt")
+	_, err := os.ReadFile(pDir + "/status.txt")
 	if err == nil {
 		t.Error("this should fail")
 	}
diff --git a/tests/matrix/matrix_test.go b/tests/matrix/matrix_test.go
index 417e126..b406517 100644
--- a/tests/matrix/matrix_test.go
+++ b/tests/matrix/matrix_test.go
@@ -10,7 +10,6 @@ import (
 	"bytes"
 	"flag"
 	"fmt"
-	"io/ioutil"
 	"math/rand"
 	"os"
 	"os/exec"
@@ -327,7 +326,7 @@ func TestFileHoles(t *testing.T) {
 	foo := []byte("foo")
 	file.Write(foo)
 	file.WriteAt(foo, 4096)
-	_, err = ioutil.ReadFile(fn)
+	_, err = os.ReadFile(fn)
 	if err != nil {
 		t.Error(err)
 	}
@@ -391,7 +390,7 @@ func TestRmwRace(t *testing.T) {
 		// but it must not be
 		// [oooooossss]
 
-		buf, _ := ioutil.ReadFile(fn)
+		buf, _ := os.ReadFile(fn)
 		m := test_helpers.Md5hex(buf)
 		goodMd5[m] = goodMd5[m] + 1
 
@@ -495,7 +494,7 @@ func TestNameLengths(t *testing.T) {
 }
 
 func TestLongNames(t *testing.T) {
-	fi, err := ioutil.ReadDir(test_helpers.DefaultCipherDir)
+	fi, err := os.ReadDir(test_helpers.DefaultCipherDir)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -607,7 +606,7 @@ func TestLongNames(t *testing.T) {
 		t.Error(err)
 	}
 	// Check for orphaned files
-	fi, err = ioutil.ReadDir(test_helpers.DefaultCipherDir)
+	fi, err = os.ReadDir(test_helpers.DefaultCipherDir)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -740,7 +739,7 @@ func doTestUtimesNano(t *testing.T, path string) {
 // Set nanoseconds by path, normal file
 func TestUtimesNano(t *testing.T) {
 	path := test_helpers.DefaultPlainDir + "/utimesnano"
-	err := ioutil.WriteFile(path, []byte("foobar"), 0600)
+	err := os.WriteFile(path, []byte("foobar"), 0600)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -788,7 +787,7 @@ func TestMagicNames(t *testing.T) {
 		t.Logf("Testing n=%q", n)
 		p := test_helpers.DefaultPlainDir + "/" + n
 		// Create file
-		err := ioutil.WriteFile(p, []byte("xxxxxxx"), 0200)
+		err := os.WriteFile(p, []byte("xxxxxxx"), 0200)
 		if err != nil {
 			t.Fatalf("creating file %q failed: %v", n, err)
 		}
@@ -825,7 +824,7 @@ func TestMagicNames(t *testing.T) {
 		syscall.Unlink(p)
 		// Link
 		target := test_helpers.DefaultPlainDir + "/linktarget"
-		err = ioutil.WriteFile(target, []byte("yyyyy"), 0600)
+		err = os.WriteFile(target, []byte("yyyyy"), 0600)
 		if err != nil {
 			t.Fatal(err)
 		}
diff --git a/tests/plaintextnames/plaintextnames_test.go b/tests/plaintextnames/plaintextnames_test.go
index 4de0730..a755deb 100644
--- a/tests/plaintextnames/plaintextnames_test.go
+++ b/tests/plaintextnames/plaintextnames_test.go
@@ -4,7 +4,6 @@ package plaintextnames
 
 import (
 	"fmt"
-	"io/ioutil"
 	"os"
 	"syscall"
 	"testing"
@@ -63,7 +62,7 @@ func TestDirIV(t *testing.T) {
 // else should work.
 func TestFiltered(t *testing.T) {
 	filteredFile := pDir + "/gocryptfs.conf"
-	err := ioutil.WriteFile(filteredFile, []byte("foo"), 0777)
+	err := os.WriteFile(filteredFile, []byte("foo"), 0777)
 	if err == nil {
 		t.Errorf("should have failed but didn't")
 	}
@@ -71,11 +70,11 @@ func TestFiltered(t *testing.T) {
 	if err == nil {
 		t.Errorf("should have failed but didn't")
 	}
-	err = ioutil.WriteFile(pDir+"/gocryptfs.diriv", []byte("foo"), 0777)
+	err = os.WriteFile(pDir+"/gocryptfs.diriv", []byte("foo"), 0777)
 	if err != nil {
 		t.Error(err)
 	}
-	subDir, err := ioutil.TempDir(pDir, "")
+	subDir, err := os.MkdirTemp(pDir, "")
 	if err != nil {
 		t.Fatal(err)
 	}
diff --git a/tests/reverse/correctness_test.go b/tests/reverse/correctness_test.go
index e4684df..4028ac3 100644
--- a/tests/reverse/correctness_test.go
+++ b/tests/reverse/correctness_test.go
@@ -3,7 +3,6 @@ package reverse_test
 import (
 	"bytes"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strings"
@@ -72,7 +71,7 @@ func TestSymlinkDentrySize(t *testing.T) {
 	}
 	symlink := "a_symlink"
 
-	mnt, err := ioutil.TempDir(test_helpers.TmpDir, "reverse_mnt_")
+	mnt, err := os.MkdirTemp(test_helpers.TmpDir, "reverse_mnt_")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -111,7 +110,7 @@ func TestConfigMapping(t *testing.T) {
 	if !test_helpers.VerifyExistence(t, c) {
 		t.Errorf("%s missing", c)
 	}
-	data, err := ioutil.ReadFile(c)
+	data, err := os.ReadFile(c)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -233,7 +232,7 @@ func Test0100Dir(t *testing.T) {
 		t.Fatal(err)
 	}
 	file := dir + "/hello"
-	err = ioutil.WriteFile(file, []byte("hello"), 0600)
+	err = os.WriteFile(file, []byte("hello"), 0600)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -328,7 +327,7 @@ func TestHardlinkedLongname(t *testing.T) {
 	workdirA, workdirB := newWorkdir(t)
 
 	long1 := workdirA + "/" + strings.Repeat("x", 200)
-	if err := ioutil.WriteFile(long1, []byte("hello"), 0600); err != nil {
+	if err := os.WriteFile(long1, []byte("hello"), 0600); err != nil {
 		t.Fatal(err)
 	}
 	var long1_stat syscall.Stat_t
diff --git a/tests/reverse/ctlsock_test.go b/tests/reverse/ctlsock_test.go
index f59fa45..8f9d843 100644
--- a/tests/reverse/ctlsock_test.go
+++ b/tests/reverse/ctlsock_test.go
@@ -1,7 +1,7 @@
 package reverse_test
 
 import (
-	"io/ioutil"
+	"os"
 	"syscall"
 	"testing"
 
@@ -28,7 +28,7 @@ func TestCtlSockPathOps(t *testing.T) {
 	if plaintextnames {
 		t.Skip("this only tests encrypted names")
 	}
-	mnt, err := ioutil.TempDir(test_helpers.TmpDir, "reverse_mnt_")
+	mnt, err := os.MkdirTemp(test_helpers.TmpDir, "reverse_mnt_")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -74,7 +74,7 @@ func TestCtlSockCrash(t *testing.T) {
 	if plaintextnames {
 		t.Skip("this only tests encrypted names")
 	}
-	mnt, err := ioutil.TempDir(test_helpers.TmpDir, "reverse_mnt_")
+	mnt, err := os.MkdirTemp(test_helpers.TmpDir, "reverse_mnt_")
 	if err != nil {
 		t.Fatal(err)
 	}
diff --git a/tests/reverse/force_owner_test.go b/tests/reverse/force_owner_test.go
index 6e47b50..aeb0a4e 100644
--- a/tests/reverse/force_owner_test.go
+++ b/tests/reverse/force_owner_test.go
@@ -1,7 +1,6 @@
 package reverse_test
 
 import (
-	"io/ioutil"
 	"net/url"
 	"os"
 	"syscall"
@@ -13,7 +12,7 @@ import (
 func TestForceOwner(t *testing.T) {
 	// Let's not explode with "TempDir: pattern contains path separator"
 	myEscapedName := url.PathEscape(t.Name())
-	mnt, err := ioutil.TempDir(test_helpers.TmpDir, myEscapedName)
+	mnt, err := os.MkdirTemp(test_helpers.TmpDir, myEscapedName)
 	if err != nil {
 		t.Fatal(err)
 	}
diff --git a/tests/reverse/one_file_system_test.go b/tests/reverse/one_file_system_test.go
index 61190ea..5bc965f 100644
--- a/tests/reverse/one_file_system_test.go
+++ b/tests/reverse/one_file_system_test.go
@@ -17,7 +17,7 @@ func TestOneFileSystem(t *testing.T) {
 	}
 	// Let's not explode with "TempDir: pattern contains path separator"
 	myEscapedName := url.PathEscape(t.Name())
-	mnt, err := ioutil.TempDir(test_helpers.TmpDir, myEscapedName)
+	mnt, err := os.MkdirTemp(test_helpers.TmpDir, myEscapedName)
 	if err != nil {
 		t.Fatal(err)
 	}
diff --git a/tests/reverse/xattr_test.go b/tests/reverse/xattr_test.go
index 8002604..a459808 100644
--- a/tests/reverse/xattr_test.go
+++ b/tests/reverse/xattr_test.go
@@ -2,7 +2,7 @@ package reverse_test
 
 import (
 	"fmt"
-	"io/ioutil"
+	"os"
 	"path/filepath"
 	"syscall"
 	"testing"
@@ -29,7 +29,7 @@ func TestXattrList(t *testing.T) {
 		t.Skip()
 	}
 	fnA := filepath.Join(dirA, t.Name())
-	err := ioutil.WriteFile(fnA, nil, 0700)
+	err := os.WriteFile(fnA, nil, 0700)
 	if err != nil {
 		t.Fatalf("creating empty file failed: %v", err)
 	}
diff --git a/tests/root_test/issue893_test.go b/tests/root_test/issue893_test.go
index 6ad8e6d..2db0b19 100644
--- a/tests/root_test/issue893_test.go
+++ b/tests/root_test/issue893_test.go
@@ -4,7 +4,6 @@ package root_test
 
 import (
 	"fmt"
-	"io/ioutil"
 	"os"
 	"sync"
 	"syscall"
@@ -35,10 +34,10 @@ func TestConcurrentUserOps(t *testing.T) {
 				if err = os.MkdirAll(d, 0700); err != nil {
 					return
 				}
-				if err = ioutil.WriteFile(d+"/foo", nil, 0400); err != nil {
+				if err = os.WriteFile(d+"/foo", nil, 0400); err != nil {
 					return
 				}
-				if err = ioutil.WriteFile(d+"/bar", []byte("aaaaaaaaaaaaaaaaaaaaa"), 0400); err != nil {
+				if err = os.WriteFile(d+"/bar", []byte("aaaaaaaaaaaaaaaaaaaaa"), 0400); err != nil {
 					return
 				}
 				if err = syscall.Unlink(d + "/foo"); err != nil {
diff --git a/tests/root_test/root_test.go b/tests/root_test/root_test.go
index 9ce1f4b..7bc3ebc 100644
--- a/tests/root_test/root_test.go
+++ b/tests/root_test/root_test.go
@@ -5,7 +5,6 @@
 package root_test
 
 import (
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -203,7 +202,7 @@ func TestDiskFull(t *testing.T) {
 	}
 	t.Logf("sz1=%d, sz2=%d", sz1, sz2)
 
-	foo1, err := ioutil.ReadFile(mnt + "/foo1")
+	foo1, err := os.ReadFile(mnt + "/foo1")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -211,7 +210,7 @@ func TestDiskFull(t *testing.T) {
 		t.Fail()
 	}
 
-	foo2, err := ioutil.ReadFile(mnt + "/foo2")
+	foo2, err := os.ReadFile(mnt + "/foo2")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -231,7 +230,7 @@ func TestAcl(t *testing.T) {
 	defer test_helpers.UnmountPanic(pDir)
 
 	f1 := pDir + "/f1"
-	if err := ioutil.WriteFile(f1, []byte("hello world\n"), 000); err != nil {
+	if err := os.WriteFile(f1, []byte("hello world\n"), 000); err != nil {
 		t.Fatal(err)
 	}
 
diff --git a/tests/test_helpers/helpers.go b/tests/test_helpers/helpers.go
index 0d21548..c8cd151 100644
--- a/tests/test_helpers/helpers.go
+++ b/tests/test_helpers/helpers.go
@@ -5,7 +5,6 @@ import (
 	"crypto/md5"
 	"encoding/hex"
 	"fmt"
-	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -55,7 +54,7 @@ func doInit() {
 		fmt.Printf("test_helpers: warning: testParentDir %q does not reside on ext4, we will miss failures caused by ino reuse\n", testParentDir)
 	}
 	var err error
-	TmpDir, err = ioutil.TempDir(testParentDir, "")
+	TmpDir, err = os.MkdirTemp(testParentDir, "")
 	if err != nil {
 		panic(err)
 	}
@@ -73,7 +72,7 @@ func doInit() {
 //	    *-- gocryptfs.diriv
 func ResetTmpDir(createDirIV bool) {
 	// Try to unmount and delete everything
-	entries, err := ioutil.ReadDir(TmpDir)
+	entries, err := os.ReadDir(TmpDir)
 	if err == nil {
 		for _, e := range entries {
 			d := filepath.Join(TmpDir, e.Name())
@@ -148,7 +147,7 @@ func InitFS(t *testing.T, extraArgs ...string) string {
 	if t != nil {
 		prefix = t.Name() + "."
 	}
-	dir, err := ioutil.TempDir(TmpDir, prefix)
+	dir, err := os.MkdirTemp(TmpDir, prefix)
 	if err != nil {
 		if t != nil {
 			t.Fatal(err)
@@ -178,7 +177,7 @@ func InitFS(t *testing.T, extraArgs ...string) string {
 
 // Md5fn returns an md5 string for file "filename"
 func Md5fn(filename string) string {
-	buf, err := ioutil.ReadFile(filename)
+	buf, err := os.ReadFile(filename)
 	if err != nil {
 		fmt.Printf("ReadFile: %v\n", err)
 		return ""
@@ -199,7 +198,7 @@ func Md5hex(buf []byte) string {
 // 3) Size reported by Fstat()
 func VerifySize(t *testing.T, path string, want int) {
 	// Read whole file
-	buf, err := ioutil.ReadFile(path)
+	buf, err := os.ReadFile(path)
 	if err != nil {
 		t.Errorf("ReadFile failed: %v", err)
 	} else if len(buf) != want {
@@ -299,7 +298,7 @@ func TestMkdirRmdir(t *testing.T, plainDir string) {
 func TestRename(t *testing.T, plainDir string) {
 	file1 := plainDir + "/rename1"
 	file2 := plainDir + "/rename2"
-	err := ioutil.WriteFile(file1, []byte("content"), 0777)
+	err := os.WriteFile(file1, []byte("content"), 0777)
 	if err != nil {
 		t.Error(err)
 		return
diff --git a/tests/xattr/xattr_fd_test.go b/tests/xattr/xattr_fd_test.go
index f3586cf..ae53afc 100644
--- a/tests/xattr/xattr_fd_test.go
+++ b/tests/xattr/xattr_fd_test.go
@@ -6,7 +6,7 @@
 package xattr_tests
 
 import (
-	"io/ioutil"
+	"os"
 	"syscall"
 	"testing"
 
@@ -18,7 +18,7 @@ import (
 func TestFdXattr(t *testing.T) {
 	attr := "user.foo"
 	fn := test_helpers.DefaultPlainDir + "/TestFdXattr"
-	err := ioutil.WriteFile(fn, nil, 0700)
+	err := os.WriteFile(fn, nil, 0700)
 	if err != nil {
 		t.Fatalf("creating empty file failed: %v", err)
 	}
diff --git a/tests/xattr/xattr_integration_test.go b/tests/xattr/xattr_integration_test.go
index c968a47..1a5d540 100644
--- a/tests/xattr/xattr_integration_test.go
+++ b/tests/xattr/xattr_integration_test.go
@@ -10,7 +10,6 @@ import (
 	"bytes"
 	"encoding/base64"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"strings"
 	"syscall"
@@ -31,7 +30,7 @@ func TestMain(m *testing.M) {
 	// Write deterministic diriv so encrypted filenames are deterministic.
 	os.Remove(test_helpers.DefaultCipherDir + "/gocryptfs.diriv")
 	diriv := []byte("1234567890123456")
-	err := ioutil.WriteFile(test_helpers.DefaultCipherDir+"/gocryptfs.diriv", diriv, 0400)
+	err := os.WriteFile(test_helpers.DefaultCipherDir+"/gocryptfs.diriv", diriv, 0400)
 	if err != nil {
 		fmt.Println(err)
 		os.Exit(1)
@@ -92,7 +91,7 @@ func setGetRmList3(fn string, attr string, val []byte) error {
 // Test xattr set, get, rm on a regular file.
 func TestSetGetRmRegularFile(t *testing.T) {
 	fn := test_helpers.DefaultPlainDir + "/TestSetGetRmRegularFile"
-	err := ioutil.WriteFile(fn, []byte("12345"), 0700)
+	err := os.WriteFile(fn, []byte("12345"), 0700)
 	if err != nil {
 		t.Fatalf("creating empty file failed: %v", err)
 	}
@@ -132,7 +131,7 @@ func TestSetGetRmDir(t *testing.T) {
 func TestXattrSetEmpty(t *testing.T) {
 	attr := "user.foo"
 	fn := test_helpers.DefaultPlainDir + "/TestXattrSetEmpty1"
-	err := ioutil.WriteFile(fn, nil, 0700)
+	err := os.WriteFile(fn, nil, 0700)
 	if err != nil {
 		t.Fatalf("creating empty file failed: %v", err)
 	}
@@ -185,7 +184,7 @@ func TestXattrSetEmpty(t *testing.T) {
 
 func TestXattrList(t *testing.T) {
 	fn := test_helpers.DefaultPlainDir + "/TestXattrList"
-	err := ioutil.WriteFile(fn, nil, 0700)
+	err := os.WriteFile(fn, nil, 0700)
 	if err != nil {
 		t.Fatalf("creating empty file failed: %v", err)
 	}
@@ -236,7 +235,7 @@ func TestBase64XattrRead(t *testing.T) {
 
 	plainFn := test_helpers.DefaultPlainDir + "/" + fileName
 	encryptedFn := test_helpers.DefaultCipherDir + "/" + encryptedFileName
-	err := ioutil.WriteFile(plainFn, nil, 0700)
+	err := os.WriteFile(plainFn, nil, 0700)
 	if err != nil {
 		t.Fatalf("creating empty file failed: %v", err)
 	}
@@ -289,7 +288,7 @@ func TestBase64XattrRead(t *testing.T) {
 // Listing xattrs should work even when we don't have read access
 func TestList0000File(t *testing.T) {
 	fn := test_helpers.DefaultPlainDir + "/TestList0000File"
-	err := ioutil.WriteFile(fn, nil, 0000)
+	err := os.WriteFile(fn, nil, 0000)
 	if err != nil {
 		t.Fatalf("creating empty file failed: %v", err)
 	}
@@ -302,7 +301,7 @@ func TestList0000File(t *testing.T) {
 // Setting xattrs should work even when we don't have read access
 func TestSet0200File(t *testing.T) {
 	fn := test_helpers.DefaultPlainDir + "/TestSet0200File"
-	err := ioutil.WriteFile(fn, nil, 0200)
+	err := os.WriteFile(fn, nil, 0200)
 	if err != nil {
 		t.Fatalf("creating empty file failed: %v", err)
 	}
@@ -342,7 +341,7 @@ func TestSet0200Dir(t *testing.T) {
 
 func TestAcl(t *testing.T) {
 	fn := test_helpers.DefaultPlainDir + "/TestAcl"
-	err := ioutil.WriteFile(fn, nil, 0600)
+	err := os.WriteFile(fn, nil, 0600)
 	if err != nil {
 		t.Fatalf("creating empty file failed: %v", err)
 	}
@@ -374,7 +373,7 @@ func TestAcl(t *testing.T) {
 // https://github.com/rfjakob/gocryptfs/issues/627
 func TestSlashInName(t *testing.T) {
 	fn := test_helpers.DefaultPlainDir + "/" + t.Name()
-	err := ioutil.WriteFile(fn, []byte("12345"), 0700)
+	err := os.WriteFile(fn, []byte("12345"), 0700)
 	if err != nil {
 		t.Fatalf("creating empty file failed: %v", err)
 	}