From dc9d46cd61ed7661400d06ddd62ebddb7a44cf6d Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Thu, 28 Jul 2022 16:57:44 +0200
Subject: [PATCH 01/43] Added first draft for a raw json local file storage.

Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 client/filejsonstore/filejsonstore.go | 95 +++++++++++++++++++++++++++
 1 file changed, 95 insertions(+)
 create mode 100644 client/filejsonstore/filejsonstore.go

diff --git a/client/filejsonstore/filejsonstore.go b/client/filejsonstore/filejsonstore.go
new file mode 100644
index 00000000..1a963112
--- /dev/null
+++ b/client/filejsonstore/filejsonstore.go
@@ -0,0 +1,95 @@
+package filejsonstore
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+)
+
+type FileJSONStore struct {
+	f       *os.File
+	baseDir string
+}
+
+func New(baseDir string) (*FileJSONStore, error) {
+	return newImpl(baseDir, true)
+}
+
+func newImpl(baseDir string, recurse bool) (*FileJSONStore, error) {
+	var f = FileJSONStore{
+		baseDir: baseDir,
+	}
+	var err error
+
+	if f.f, err = os.Open(baseDir); err != nil {
+		pe, ok := err.(*os.PathError)
+		fmt.Println(ok)
+		fmt.Println(pe.Err)
+		if ok && errors.Is(pe.Err, os.ErrNotExist) && recurse {
+			// Create the directory
+			err = os.Mkdir(baseDir, 0750)
+			if err == nil {
+				return newImpl(baseDir, false)
+			}
+			return nil, err
+		} else {
+			return nil, err
+		}
+	}
+
+	if stat, err := f.f.Stat(); err != nil {
+		f.f.Close()
+		return nil, fmt.Errorf("failed to stat file %s: %w",
+			baseDir, err)
+	} else {
+		if !stat.IsDir() {
+			f.f.Close()
+			return nil, fmt.Errorf("can not open %s, not a directory",
+				baseDir)
+		}
+	}
+
+	return &f, nil
+}
+
+func (f *FileJSONStore) GetMeta() (map[string]json.RawMessage, error) {
+	names, err := f.f.Readdirnames(0)
+
+	if err != nil {
+		return nil, err
+	}
+
+	meta := map[string]json.RawMessage{}
+	for _, name := range names {
+		p := filepath.FromSlash(filepath.Join(f.baseDir, name))
+		b, err := os.ReadFile(p)
+		if err != nil {
+			return nil, err
+		}
+		meta[name] = b
+	}
+
+	return meta, nil
+}
+
+func (f *FileJSONStore) SetMeta(name string, meta json.RawMessage) error {
+	p := filepath.FromSlash(filepath.Join(f.baseDir, name))
+	return os.WriteFile(p, meta, 0640)
+}
+
+func (f *FileJSONStore) DeleteMeta(name string) error {
+	p := filepath.FromSlash(filepath.Join(f.baseDir, name))
+	return os.Remove(p)
+}
+
+func (f *FileJSONStore) Close() error {
+	if f == nil {
+		return nil
+	}
+	if f.f != nil {
+		return f.f.Close()
+	}
+	return nil
+}

From c41bd2d9adc1ddaea2e41d67023f54f961201a26 Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Thu, 28 Jul 2022 16:58:23 +0200
Subject: [PATCH 02/43] Ignore emacs temporary files

Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 .gitignore | 1 +
 1 file changed, 1 insertion(+)

diff --git a/.gitignore b/.gitignore
index 64b8f8a8..39e7149c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,3 +2,4 @@
 cmd/tuf/tuf
 cmd/tuf-client/tuf-client
 .vscode
+*~

From 9fdf33211bc51850741257d2fe902f5ba9002c3e Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Fri, 29 Jul 2022 13:35:49 +0200
Subject: [PATCH 03/43] moved isMetaFile to util directory for reuse in other
 packages.

Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 local_store.go | 17 ++---------------
 util/util.go   | 14 ++++++++++++++
 2 files changed, 16 insertions(+), 15 deletions(-)

diff --git a/local_store.go b/local_store.go
index 9fd95dc5..86aed2c9 100644
--- a/local_store.go
+++ b/local_store.go
@@ -222,19 +222,6 @@ func (f *fileSystemStore) stagedDir() string {
 	return filepath.Join(f.dir, "staged")
 }
 
-func isMetaFile(e os.DirEntry) (bool, error) {
-	if e.IsDir() || filepath.Ext(e.Name()) != ".json" {
-		return false, nil
-	}
-
-	info, err := e.Info()
-	if err != nil {
-		return false, err
-	}
-
-	return info.Mode().IsRegular(), nil
-}
-
 func (f *fileSystemStore) GetMeta() (map[string]json.RawMessage, error) {
 	// Build a map of metadata names (e.g. root.json) to their full paths
 	// (whether in the committed repo dir, or in the staged repo dir).
@@ -247,7 +234,7 @@ func (f *fileSystemStore) GetMeta() (map[string]json.RawMessage, error) {
 	}
 
 	for _, e := range committed {
-		imf, err := isMetaFile(e)
+		imf, err := util.IsMetaFile(e)
 		if err != nil {
 			return nil, err
 		}
@@ -264,7 +251,7 @@ func (f *fileSystemStore) GetMeta() (map[string]json.RawMessage, error) {
 	}
 
 	for _, e := range staged {
-		imf, err := isMetaFile(e)
+		imf, err := util.IsMetaFile(e)
 		if err != nil {
 			return nil, err
 		}
diff --git a/util/util.go b/util/util.go
index 0878c823..dfcb67f3 100644
--- a/util/util.go
+++ b/util/util.go
@@ -331,3 +331,17 @@ func AtomicallyWriteFile(filename string, data []byte, perm os.FileMode) error {
 
 	return nil
 }
+
+// IsMetaFile tests wheter a DirEntry appears to be a metaddata file or not.
+func IsMetaFile(e os.DirEntry) (bool, error) {
+	if e.IsDir() || filepath.Ext(e.Name()) != ".json" {
+		return false, nil
+	}
+
+	info, err := e.Info()
+	if err != nil {
+		return false, err
+	}
+
+	return info.Mode().IsRegular(), nil
+}

From 1acc7bf0bd536434ead0263f5980a3f9c5a23e7d Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Fri, 29 Jul 2022 13:36:49 +0200
Subject: [PATCH 04/43] Added unit tests and refactored code to match the local
 store for repository side.

Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 client/filejsonstore/filejsonstore.go      |  61 +++++-----
 client/filejsonstore/filejsonstore_test.go | 132 +++++++++++++++++++++
 2 files changed, 165 insertions(+), 28 deletions(-)
 create mode 100644 client/filejsonstore/filejsonstore_test.go

diff --git a/client/filejsonstore/filejsonstore.go b/client/filejsonstore/filejsonstore.go
index 1a963112..e48ce3c1 100644
--- a/client/filejsonstore/filejsonstore.go
+++ b/client/filejsonstore/filejsonstore.go
@@ -6,10 +6,13 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+
+	"github.com/theupdateframework/go-tuf/util"
 )
 
+var ErrNotJSON = errors.New("file is not in JSON format")
+
 type FileJSONStore struct {
-	f       *os.File
 	baseDir string
 }
 
@@ -23,39 +26,33 @@ func newImpl(baseDir string, recurse bool) (*FileJSONStore, error) {
 	}
 	var err error
 
-	if f.f, err = os.Open(baseDir); err != nil {
+	// Does the directory exist?
+	fi, err := os.Stat(baseDir)
+	if err != nil {
 		pe, ok := err.(*os.PathError)
-		fmt.Println(ok)
-		fmt.Println(pe.Err)
 		if ok && errors.Is(pe.Err, os.ErrNotExist) && recurse {
 			// Create the directory
+			// user:  rwx
+			// group: r-x
+			// other: ---
 			err = os.Mkdir(baseDir, 0750)
 			if err == nil {
 				return newImpl(baseDir, false)
 			}
-			return nil, err
-		} else {
-			return nil, err
 		}
+		return nil, err
 	}
 
-	if stat, err := f.f.Stat(); err != nil {
-		f.f.Close()
-		return nil, fmt.Errorf("failed to stat file %s: %w",
-			baseDir, err)
-	} else {
-		if !stat.IsDir() {
-			f.f.Close()
-			return nil, fmt.Errorf("can not open %s, not a directory",
-				baseDir)
-		}
+	if !fi.IsDir() {
+		return nil, fmt.Errorf("can not open %s, not a directory",
+			baseDir)
 	}
 
 	return &f, nil
 }
 
 func (f *FileJSONStore) GetMeta() (map[string]json.RawMessage, error) {
-	names, err := f.f.Readdirnames(0)
+	names, err := os.ReadDir(f.baseDir)
 
 	if err != nil {
 		return nil, err
@@ -63,33 +60,41 @@ func (f *FileJSONStore) GetMeta() (map[string]json.RawMessage, error) {
 
 	meta := map[string]json.RawMessage{}
 	for _, name := range names {
-		p := filepath.FromSlash(filepath.Join(f.baseDir, name))
+		p := filepath.FromSlash(filepath.Join(f.baseDir, name.Name()))
+		if ok, err := util.IsMetaFile(name); !ok {
+			continue
+		} else if err != nil {
+			return nil, err
+		}
 		b, err := os.ReadFile(p)
 		if err != nil {
 			return nil, err
 		}
-		meta[name] = b
+		meta[name.Name()] = b
 	}
 
 	return meta, nil
 }
 
 func (f *FileJSONStore) SetMeta(name string, meta json.RawMessage) error {
+	if filepath.Ext(name) != ".json" {
+		return ErrNotJSON
+	}
+
 	p := filepath.FromSlash(filepath.Join(f.baseDir, name))
-	return os.WriteFile(p, meta, 0640)
+	// user:  rw-
+	// group: r--
+	// other: ---
+	err := util.AtomicallyWriteFile(p, meta, 0640)
+	return err
 }
 
 func (f *FileJSONStore) DeleteMeta(name string) error {
 	p := filepath.FromSlash(filepath.Join(f.baseDir, name))
-	return os.Remove(p)
+	err := os.Remove(p)
+	return err
 }
 
 func (f *FileJSONStore) Close() error {
-	if f == nil {
-		return nil
-	}
-	if f.f != nil {
-		return f.f.Close()
-	}
 	return nil
 }
diff --git a/client/filejsonstore/filejsonstore_test.go b/client/filejsonstore/filejsonstore_test.go
new file mode 100644
index 00000000..65fc73a8
--- /dev/null
+++ b/client/filejsonstore/filejsonstore_test.go
@@ -0,0 +1,132 @@
+package filejsonstore
+
+import (
+	"encoding/json"
+	"errors"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"gopkg.in/check.v1"
+)
+
+type RawJSONStoreSuite struct{}
+
+var _ = check.Suite(&RawJSONStoreSuite{})
+
+// Hook up gocheck into the "go test" runnder
+func Test(t *testing.T) { check.TestingT(t) }
+
+func (RawJSONStoreSuite) TestNewOk(c *check.C) {
+	tmp := c.MkDir()
+	p := filepath.Join(tmp, "tuf_raw.db")
+
+	// Assert path does not exist
+	fi, err := os.Stat(p)
+	c.Assert(fi, check.IsNil)
+	c.Assert(errors.Is(err, os.ErrNotExist), check.Equals, true)
+
+	// Create implementation
+	s, err := New(p)
+	c.Assert(err, check.IsNil)
+	c.Assert(s, check.NotNil)
+
+	// Assert path does exist and is a directory
+	fi, err = os.Stat(p)
+	c.Assert(fi, check.NotNil)
+	c.Assert(err, check.IsNil)
+	c.Assert(fi.IsDir(), check.Equals, true)
+}
+
+func (RawJSONStoreSuite) TestNewFileExists(c *check.C) {
+	tmp := c.MkDir()
+	p := filepath.Join(tmp, "tuf_raw.db")
+
+	// Create an empty file
+	f, err := os.Create(p)
+	c.Assert(err, check.IsNil)
+	f.Close()
+
+	// Create implementation
+	s, err := New(p)
+	c.Assert(s, check.IsNil)
+	c.Assert(err, check.NotNil)
+	found := strings.Contains(err.Error(), ", not a directory")
+	c.Assert(found, check.Equals, true)
+}
+
+func (RawJSONStoreSuite) TestGetMetaEmpty(c *check.C) {
+	tmp := c.MkDir()
+	p := filepath.Join(tmp, "tuf_raw.db")
+	s, err := New(p)
+
+	md, err := s.GetMeta()
+	c.Assert(err, check.IsNil)
+	c.Assert(md, check.HasLen, 0)
+}
+
+func (RawJSONStoreSuite) TestMetadataOperations(c *check.C) {
+	tmp := c.MkDir()
+	p := filepath.Join(tmp, "tuf_raw.db")
+	s, err := New(p)
+	expected := map[string]json.RawMessage{
+		"file1.json": []byte{0xf1, 0xe1, 0xd1},
+		"file2.json": []byte{0xf2, 0xe2, 0xd2},
+		"file3.json": []byte{0xf3, 0xe3, 0xd3},
+	}
+
+	for k, v := range expected {
+		s.SetMeta(k, v)
+	}
+
+	md, err := s.GetMeta()
+	c.Assert(err, check.IsNil)
+	c.Assert(md, check.HasLen, 3)
+	c.Assert(md, check.DeepEquals, expected)
+
+	// Nuke items
+	count := 3
+	for k := range expected {
+		err = s.DeleteMeta(k)
+		count--
+		c.Assert(err, check.IsNil)
+		md, err := s.GetMeta()
+		c.Assert(err, check.IsNil)
+		c.Assert(md, check.HasLen, count)
+	}
+
+	md, err = s.GetMeta()
+	c.Assert(err, check.IsNil)
+	c.Assert(md, check.HasLen, 0)
+}
+
+func (RawJSONStoreSuite) TestNoJSON(c *check.C) {
+	tmp := c.MkDir()
+	p := filepath.Join(tmp, "tuf_raw.db")
+	s, err := New(p)
+	c.Assert(s, check.NotNil)
+	c.Assert(err, check.IsNil)
+
+	files := []string{
+		"file.xml",
+		"file",
+		"",
+	}
+	for _, f := range files {
+		err := s.SetMeta(f, []byte{})
+		c.Assert(err, check.Equals, ErrNotJSON)
+	}
+
+}
+
+func (RawJSONStoreSuite) TestClose(c *check.C) {
+	tmp := c.MkDir()
+	p := filepath.Join(tmp, "tuf_raw.db")
+	s, err := New(p)
+	c.Assert(s, check.NotNil)
+	c.Assert(err, check.IsNil)
+
+	err = s.Close()
+	c.Assert(err, check.IsNil)
+}

From c527e56034fcd9d6d404e9094addd7b789fd1327 Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Fri, 29 Jul 2022 14:09:34 +0200
Subject: [PATCH 05/43] Added test case for non json file in metadata
 directory. Changed package to client to align with leveldb storage.

Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 client/filejsonstore/filejsonstore.go      |  2 +-
 client/filejsonstore/filejsonstore_test.go | 18 +++++++++++++++++-
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/client/filejsonstore/filejsonstore.go b/client/filejsonstore/filejsonstore.go
index e48ce3c1..15943886 100644
--- a/client/filejsonstore/filejsonstore.go
+++ b/client/filejsonstore/filejsonstore.go
@@ -1,4 +1,4 @@
-package filejsonstore
+package client
 
 import (
 	"encoding/json"
diff --git a/client/filejsonstore/filejsonstore_test.go b/client/filejsonstore/filejsonstore_test.go
index 65fc73a8..5577aab6 100644
--- a/client/filejsonstore/filejsonstore_test.go
+++ b/client/filejsonstore/filejsonstore_test.go
@@ -1,4 +1,4 @@
-package filejsonstore
+package client
 
 import (
 	"encoding/json"
@@ -101,6 +101,22 @@ func (RawJSONStoreSuite) TestMetadataOperations(c *check.C) {
 	c.Assert(md, check.HasLen, 0)
 }
 
+func (RawJSONStoreSuite) TestGetNoJSON(c *check.C) {
+	tmp := c.MkDir()
+	p := filepath.Join(tmp, "tuf_raw.db")
+	s, err := New(p)
+	c.Assert(s, check.NotNil)
+	c.Assert(err, check.IsNil)
+
+	// Create a file which does not end with '.json'
+	fp := filepath.FromSlash(filepath.Join(p, "meta.xml"))
+	os.WriteFile(fp, []byte{}, 0644)
+
+	md, err := s.GetMeta()
+	c.Assert(err, check.IsNil)
+	c.Assert(md, check.HasLen, 0)
+}
+
 func (RawJSONStoreSuite) TestNoJSON(c *check.C) {
 	tmp := c.MkDir()
 	p := filepath.Join(tmp, "tuf_raw.db")

From b7dbd08e640e71ee04dfe98aaf87178089860802 Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Fri, 29 Jul 2022 15:33:37 +0200
Subject: [PATCH 06/43] Use os.MkdirAll when creating metadata cache.

Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 client/filejsonstore/filejsonstore.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/client/filejsonstore/filejsonstore.go b/client/filejsonstore/filejsonstore.go
index 15943886..c2c7a42e 100644
--- a/client/filejsonstore/filejsonstore.go
+++ b/client/filejsonstore/filejsonstore.go
@@ -35,7 +35,7 @@ func newImpl(baseDir string, recurse bool) (*FileJSONStore, error) {
 			// user:  rwx
 			// group: r-x
 			// other: ---
-			err = os.Mkdir(baseDir, 0750)
+			err = os.MkdirAll(baseDir, 0750)
 			if err == nil {
 				return newImpl(baseDir, false)
 			}

From 2dc5d0e3adb5a9d82d8b10319cef24d6d800e8a2 Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Mon, 1 Aug 2022 08:35:45 +0200
Subject: [PATCH 07/43] More consistent naming, added comments and a unit test.

Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 client/filejsonstore/filejsonstore.go      | 21 ++++++++++++++++-
 client/filejsonstore/filejsonstore_test.go | 27 ++++++++++++++++------
 2 files changed, 40 insertions(+), 8 deletions(-)

diff --git a/client/filejsonstore/filejsonstore.go b/client/filejsonstore/filejsonstore.go
index c2c7a42e..fb9493e7 100644
--- a/client/filejsonstore/filejsonstore.go
+++ b/client/filejsonstore/filejsonstore.go
@@ -10,13 +10,22 @@ import (
 	"github.com/theupdateframework/go-tuf/util"
 )
 
+// ErrNotJSON is returned when a metadata operation is attempted to be
+// performed against a file that does not seem to be a JSON file
+// (e.g. does not end in .json, case sensitive).
 var ErrNotJSON = errors.New("file is not in JSON format")
 
+// FileJSONStore represents a local metadata cache relying on raw JSON files
+// as retrieved from the remote repository.
 type FileJSONStore struct {
 	baseDir string
 }
 
-func New(baseDir string) (*FileJSONStore, error) {
+// NewFileJSONStore returns a new metadata cache, implemented using raw JSON
+// files, stored in a directory provided by the client.
+// If the provided directory does not exist on disk, it will be created.
+// The provided metadata cache is not safe for concurrent access.
+func NewFileJSONStore(baseDir string) (*FileJSONStore, error) {
 	return newImpl(baseDir, true)
 }
 
@@ -51,6 +60,7 @@ func newImpl(baseDir string, recurse bool) (*FileJSONStore, error) {
 	return &f, nil
 }
 
+// GetMeta returns the currently cached set of metadata files.
 func (f *FileJSONStore) GetMeta() (map[string]json.RawMessage, error) {
 	names, err := os.ReadDir(f.baseDir)
 
@@ -76,6 +86,8 @@ func (f *FileJSONStore) GetMeta() (map[string]json.RawMessage, error) {
 	return meta, nil
 }
 
+// SetMeta stores a metadata file in the cache. If the metadata file exist,
+// it will be overwritten.
 func (f *FileJSONStore) SetMeta(name string, meta json.RawMessage) error {
 	if filepath.Ext(name) != ".json" {
 		return ErrNotJSON
@@ -89,12 +101,19 @@ func (f *FileJSONStore) SetMeta(name string, meta json.RawMessage) error {
 	return err
 }
 
+// DeleteMeta deletes a metadata file from the cache.
+// If the file does not exist, an *os.PathError is returned.
 func (f *FileJSONStore) DeleteMeta(name string) error {
+	if filepath.Ext(name) != ".json" {
+		return ErrNotJSON
+	}
+
 	p := filepath.FromSlash(filepath.Join(f.baseDir, name))
 	err := os.Remove(p)
 	return err
 }
 
+// Close closes the metadata cache. This is a no-op.
 func (f *FileJSONStore) Close() error {
 	return nil
 }
diff --git a/client/filejsonstore/filejsonstore_test.go b/client/filejsonstore/filejsonstore_test.go
index 5577aab6..7a6a139c 100644
--- a/client/filejsonstore/filejsonstore_test.go
+++ b/client/filejsonstore/filejsonstore_test.go
@@ -28,7 +28,7 @@ func (RawJSONStoreSuite) TestNewOk(c *check.C) {
 	c.Assert(errors.Is(err, os.ErrNotExist), check.Equals, true)
 
 	// Create implementation
-	s, err := New(p)
+	s, err := NewFileJSONStore(p)
 	c.Assert(err, check.IsNil)
 	c.Assert(s, check.NotNil)
 
@@ -49,7 +49,7 @@ func (RawJSONStoreSuite) TestNewFileExists(c *check.C) {
 	f.Close()
 
 	// Create implementation
-	s, err := New(p)
+	s, err := NewFileJSONStore(p)
 	c.Assert(s, check.IsNil)
 	c.Assert(err, check.NotNil)
 	found := strings.Contains(err.Error(), ", not a directory")
@@ -59,7 +59,7 @@ func (RawJSONStoreSuite) TestNewFileExists(c *check.C) {
 func (RawJSONStoreSuite) TestGetMetaEmpty(c *check.C) {
 	tmp := c.MkDir()
 	p := filepath.Join(tmp, "tuf_raw.db")
-	s, err := New(p)
+	s, err := NewFileJSONStore(p)
 
 	md, err := s.GetMeta()
 	c.Assert(err, check.IsNil)
@@ -69,7 +69,7 @@ func (RawJSONStoreSuite) TestGetMetaEmpty(c *check.C) {
 func (RawJSONStoreSuite) TestMetadataOperations(c *check.C) {
 	tmp := c.MkDir()
 	p := filepath.Join(tmp, "tuf_raw.db")
-	s, err := New(p)
+	s, err := NewFileJSONStore(p)
 	expected := map[string]json.RawMessage{
 		"file1.json": []byte{0xf1, 0xe1, 0xd1},
 		"file2.json": []byte{0xf2, 0xe2, 0xd2},
@@ -104,7 +104,7 @@ func (RawJSONStoreSuite) TestMetadataOperations(c *check.C) {
 func (RawJSONStoreSuite) TestGetNoJSON(c *check.C) {
 	tmp := c.MkDir()
 	p := filepath.Join(tmp, "tuf_raw.db")
-	s, err := New(p)
+	s, err := NewFileJSONStore(p)
 	c.Assert(s, check.NotNil)
 	c.Assert(err, check.IsNil)
 
@@ -120,7 +120,7 @@ func (RawJSONStoreSuite) TestGetNoJSON(c *check.C) {
 func (RawJSONStoreSuite) TestNoJSON(c *check.C) {
 	tmp := c.MkDir()
 	p := filepath.Join(tmp, "tuf_raw.db")
-	s, err := New(p)
+	s, err := NewFileJSONStore(p)
 	c.Assert(s, check.NotNil)
 	c.Assert(err, check.IsNil)
 
@@ -139,10 +139,23 @@ func (RawJSONStoreSuite) TestNoJSON(c *check.C) {
 func (RawJSONStoreSuite) TestClose(c *check.C) {
 	tmp := c.MkDir()
 	p := filepath.Join(tmp, "tuf_raw.db")
-	s, err := New(p)
+	s, err := NewFileJSONStore(p)
 	c.Assert(s, check.NotNil)
 	c.Assert(err, check.IsNil)
 
 	err = s.Close()
 	c.Assert(err, check.IsNil)
 }
+
+func (RawJSONStoreSuite) TestDelete(c *check.C) {
+	tmp := c.MkDir()
+	p := filepath.Join(tmp, "tuf_raw.db")
+	s, err := NewFileJSONStore(p)
+	c.Assert(s, check.NotNil)
+	c.Assert(err, check.IsNil)
+
+	err = s.DeleteMeta("not_json.yml")
+	c.Assert(err, check.Equals, ErrNotJSON)
+	err = s.DeleteMeta("non_existing.json")
+	c.Assert(errors.Is(err, os.ErrNotExist), check.Equals, true)
+}

From ad4974bf2c8eb05d650578aebc0feac04b4e5de0 Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Thu, 4 Aug 2022 08:12:46 +0200
Subject: [PATCH 08/43] Added a localstore wrapper for concurrent access.

Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 client/concurrentlocalstore.go             | 49 +++++++++++++++++++
 client/concurrentlocalstore_test.go        | 55 ++++++++++++++++++++++
 client/filejsonstore/filejsonstore.go      |  4 +-
 client/filejsonstore/filejsonstore_test.go |  3 +-
 4 files changed, 109 insertions(+), 2 deletions(-)
 create mode 100644 client/concurrentlocalstore.go
 create mode 100644 client/concurrentlocalstore_test.go

diff --git a/client/concurrentlocalstore.go b/client/concurrentlocalstore.go
new file mode 100644
index 00000000..f37f7aa1
--- /dev/null
+++ b/client/concurrentlocalstore.go
@@ -0,0 +1,49 @@
+package client
+
+import (
+	"encoding/json"
+	"sync"
+)
+
+// ConcurrentLocalStore provides a LocalStore over an existing LocalStore
+// implementation that is safe for concurrent access.
+type ConcurrentLocalStore struct {
+	mtx   sync.RWMutex
+	store LocalStore
+}
+
+// NewConcurrentLocalStore returns a wrapped LocalStore that is safe for
+// concurrent access.
+func NewConcurrentLocalStore(s LocalStore) *ConcurrentLocalStore {
+	return &ConcurrentLocalStore{
+		store: s,
+	}
+}
+
+// GetMeta returns all known targets.
+func (c *ConcurrentLocalStore) GetMeta() (map[string]json.RawMessage, error) {
+	c.mtx.RLock()
+	defer c.mtx.RUnlock()
+	return c.store.GetMeta()
+}
+
+// SetMeta updates the lcoal store with a new target.
+func (c *ConcurrentLocalStore) SetMeta(name string, meta json.RawMessage) error {
+	c.mtx.Lock()
+	defer c.mtx.Unlock()
+	return c.store.SetMeta(name, meta)
+}
+
+// DeleteMeta remves a target from the cache.
+func (c *ConcurrentLocalStore) DeleteMeta(name string) error {
+	c.mtx.Lock()
+	defer c.mtx.Unlock()
+	return c.store.DeleteMeta(name)
+}
+
+// Close closes the local store.
+func (c *ConcurrentLocalStore) Close() error {
+	c.mtx.Lock()
+	defer c.mtx.Unlock()
+	return c.store.Close()
+}
diff --git a/client/concurrentlocalstore_test.go b/client/concurrentlocalstore_test.go
new file mode 100644
index 00000000..4c883f23
--- /dev/null
+++ b/client/concurrentlocalstore_test.go
@@ -0,0 +1,55 @@
+package client
+
+import (
+	"encoding/json"
+	"testing"
+
+	"gopkg.in/check.v1"
+)
+
+type ConcurrentStoreSuite struct{}
+
+var _ = check.Suite(&ConcurrentStoreSuite{})
+
+// Hook up gocheck into the "go test" runnder
+func ConcurrentTest(t *testing.T) { check.TestingT(t) }
+
+func (ConcurrentStoreSuite) TestOperations(c *check.C) {
+	mem := MemoryLocalStore()
+	store := NewConcurrentLocalStore(mem)
+
+	c.Assert(store, check.NotNil)
+	expected := map[string]json.RawMessage{
+		"file1.json": []byte{0xf1, 0xe1, 0xd1},
+		"file2.json": []byte{0xf2, 0xe2, 0xd2},
+		"file3.json": []byte{0xf3, 0xe3, 0xd3},
+	}
+
+	for k, v := range expected {
+		err := store.SetMeta(k, v)
+		c.Assert(err, check.IsNil)
+	}
+
+	md, err := store.GetMeta()
+	c.Assert(err, check.IsNil)
+	c.Assert(md, check.HasLen, 3)
+	c.Assert(md, check.DeepEquals, expected)
+
+	// Nuke items
+	count := 3
+	for k := range expected {
+		err = store.DeleteMeta(k)
+		count--
+		c.Assert(err, check.IsNil)
+		md, err := store.GetMeta()
+		c.Assert(err, check.IsNil)
+		c.Assert(md, check.HasLen, count)
+	}
+
+	md, err = store.GetMeta()
+	c.Assert(err, check.IsNil)
+	c.Assert(md, check.HasLen, 0)
+
+	err = store.Close()
+	c.Assert(err, check.IsNil)
+}
diff --git a/client/filejsonstore/filejsonstore.go b/client/filejsonstore/filejsonstore.go
index fb9493e7..06a73abd 100644
--- a/client/filejsonstore/filejsonstore.go
+++ b/client/filejsonstore/filejsonstore.go
@@ -24,7 +24,9 @@ type FileJSONStore struct {
 // NewFileJSONStore returns a new metadata cache, implemented using raw JSON
 // files, stored in a directory provided by the client.
 // If the provided directory does not exist on disk, it will be created.
-// The provided metadata cache is not safe for concurrent access.
+// The provided metadata cache is not safe for concurrent access, if
+// concurrent access safety is requires, wrap local store in a
+// ConcurrentLocalStore.
 func NewFileJSONStore(baseDir string) (*FileJSONStore, error) {
 	return newImpl(baseDir, true)
 }
diff --git a/client/filejsonstore/filejsonstore_test.go b/client/filejsonstore/filejsonstore_test.go
index 7a6a139c..a6d7cfca 100644
--- a/client/filejsonstore/filejsonstore_test.go
+++ b/client/filejsonstore/filejsonstore_test.go
@@ -77,7 +77,8 @@ func (RawJSONStoreSuite) TestMetadataOperations(c *check.C) {
 	}
 
 	for k, v := range expected {
-		s.SetMeta(k, v)
+		err := s.SetMeta(k, v)
+		c.Assert(err, check.IsNil)
 	}
 
 	md, err := s.GetMeta()

From 61c73238f437fc90853e146840169437432bb6c3 Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Wed, 3 Aug 2022 13:43:12 +0200
Subject: [PATCH 09/43] Update client/filejsonstore/filejsonstore_test.go

Fixed spelling error found during review.

Co-authored-by: Joshua Lock <jlock@vmware.com>
Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 client/filejsonstore/filejsonstore_test.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/client/filejsonstore/filejsonstore_test.go b/client/filejsonstore/filejsonstore_test.go
index a6d7cfca..778f4808 100644
--- a/client/filejsonstore/filejsonstore_test.go
+++ b/client/filejsonstore/filejsonstore_test.go
@@ -15,7 +15,7 @@ type RawJSONStoreSuite struct{}
 
 var _ = check.Suite(&RawJSONStoreSuite{})
 
-// Hook up gocheck into the "go test" runnder
+// Hook up gocheck into the "go test" runner
 func Test(t *testing.T) { check.TestingT(t) }
 
 func (RawJSONStoreSuite) TestNewOk(c *check.C) {

From 4714ff1a346d8830bc4baad8656a146301f792d7 Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Thu, 4 Aug 2022 08:44:57 +0200
Subject: [PATCH 10/43] Added tests to make sure returned struct implements
 LocalStore interface.

Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 client/concurrentlocalstore_test.go        |  4 +++-
 client/filejsonstore/filejsonstore_test.go | 13 +++++++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/client/concurrentlocalstore_test.go b/client/concurrentlocalstore_test.go
index 4c883f23..c4824f5d 100644
--- a/client/concurrentlocalstore_test.go
+++ b/client/concurrentlocalstore_test.go
@@ -15,8 +15,10 @@ var _ = check.Suite(&ConcurrentStoreSuite{})
 func ConcurrentTest(t *testing.T) { check.TestingT(t) }
 
 func (ConcurrentStoreSuite) TestOperations(c *check.C) {
+	var store LocalStore
+
 	mem := MemoryLocalStore()
-	store := NewConcurrentLocalStore(mem)
+	store = NewConcurrentLocalStore(mem)
 
 	c.Assert(store, check.NotNil)
 	expected := map[string]json.RawMessage{
diff --git a/client/filejsonstore/filejsonstore_test.go b/client/filejsonstore/filejsonstore_test.go
index 778f4808..e256f50d 100644
--- a/client/filejsonstore/filejsonstore_test.go
+++ b/client/filejsonstore/filejsonstore_test.go
@@ -9,6 +9,8 @@ import (
 	"testing"
 
 	"gopkg.in/check.v1"
+
+	"github.com/theupdateframework/go-tuf/client"
 )
 
 type RawJSONStoreSuite struct{}
@@ -160,3 +162,14 @@ func (RawJSONStoreSuite) TestDelete(c *check.C) {
 	err = s.DeleteMeta("non_existing.json")
 	c.Assert(errors.Is(err, os.ErrNotExist), check.Equals, true)
 }
+
+func (RawJSONStoreSuite) TestInterface(c *check.C) {
+	var localStore client.LocalStore
+	var err error
+
+	tmp := c.MkDir()
+	p := filepath.Join(tmp, "tuf_raw.db")
+	localStore, err = NewFileJSONStore(p)
+	c.Assert(localStore, check.NotNil)
+	c.Assert(err, check.IsNil)
+}

From 40488485a978ac76464206c4c31f857b240bc053 Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Tue, 9 Aug 2022 17:54:30 +0200
Subject: [PATCH 11/43] Update client/filejsonstore/filejsonstore.go

Co-authored-by: Ethan Lowman <53835328+ethan-lowman-dd@users.noreply.github.com>
Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 client/filejsonstore/filejsonstore.go | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/client/filejsonstore/filejsonstore.go b/client/filejsonstore/filejsonstore.go
index 06a73abd..3272b04e 100644
--- a/client/filejsonstore/filejsonstore.go
+++ b/client/filejsonstore/filejsonstore.go
@@ -10,8 +10,8 @@ import (
 	"github.com/theupdateframework/go-tuf/util"
 )
 
-// ErrNotJSON is returned when a metadata operation is attempted to be
-// performed against a file that does not seem to be a JSON file
+// ErrNotJSON is returned when a metadata operation is attempted
+// against a file that does not seem to be a JSON file
 // (e.g. does not end in .json, case sensitive).
 var ErrNotJSON = errors.New("file is not in JSON format")
 

From 1d074f8caa7bb251990e76226e16c5ec19d9ed12 Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Tue, 9 Aug 2022 17:54:55 +0200
Subject: [PATCH 12/43] Update client/filejsonstore/filejsonstore_test.go

Co-authored-by: Ethan Lowman <53835328+ethan-lowman-dd@users.noreply.github.com>
Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 client/filejsonstore/filejsonstore_test.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/client/filejsonstore/filejsonstore_test.go b/client/filejsonstore/filejsonstore_test.go
index e256f50d..130767bc 100644
--- a/client/filejsonstore/filejsonstore_test.go
+++ b/client/filejsonstore/filejsonstore_test.go
@@ -88,7 +88,7 @@ func (RawJSONStoreSuite) TestMetadataOperations(c *check.C) {
 	c.Assert(md, check.HasLen, 3)
 	c.Assert(md, check.DeepEquals, expected)
 
-	// Nuke items
+	// Delete all items
 	count := 3
 	for k := range expected {
 		err = s.DeleteMeta(k)

From 18f7ce711a5d5fe4d33e32942edb61c1aec6acc9 Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Wed, 10 Aug 2022 08:13:14 +0200
Subject: [PATCH 13/43] Update client/filejsonstore/filejsonstore.go

Co-authored-by: Ethan Lowman <53835328+ethan-lowman-dd@users.noreply.github.com>
Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 client/filejsonstore/filejsonstore.go | 1 -
 1 file changed, 1 deletion(-)

diff --git a/client/filejsonstore/filejsonstore.go b/client/filejsonstore/filejsonstore.go
index 3272b04e..dd13651f 100644
--- a/client/filejsonstore/filejsonstore.go
+++ b/client/filejsonstore/filejsonstore.go
@@ -65,7 +65,6 @@ func newImpl(baseDir string, recurse bool) (*FileJSONStore, error) {
 // GetMeta returns the currently cached set of metadata files.
 func (f *FileJSONStore) GetMeta() (map[string]json.RawMessage, error) {
 	names, err := os.ReadDir(f.baseDir)
-
 	if err != nil {
 		return nil, err
 	}

From 800da609e41bd8f56323df50ff580f36f252c858 Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Wed, 10 Aug 2022 08:13:59 +0200
Subject: [PATCH 14/43] Update client/filejsonstore/filejsonstore_test.go

Co-authored-by: Ethan Lowman <53835328+ethan-lowman-dd@users.noreply.github.com>
Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 client/filejsonstore/filejsonstore_test.go | 1 -
 1 file changed, 1 deletion(-)

diff --git a/client/filejsonstore/filejsonstore_test.go b/client/filejsonstore/filejsonstore_test.go
index 130767bc..8fb4ece6 100644
--- a/client/filejsonstore/filejsonstore_test.go
+++ b/client/filejsonstore/filejsonstore_test.go
@@ -136,7 +136,6 @@ func (RawJSONStoreSuite) TestNoJSON(c *check.C) {
 		err := s.SetMeta(f, []byte{})
 		c.Assert(err, check.Equals, ErrNotJSON)
 	}
-
 }
 
 func (RawJSONStoreSuite) TestClose(c *check.C) {

From 0627a275b11e3d8cea48e0dce0c9fd1ca821cfed Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Wed, 10 Aug 2022 10:55:40 +0200
Subject: [PATCH 15/43] Made FileJSONStore safe for concurrent access. Moved
 IsMetaFile to new pkg, internal/fsutil Permission bits are validated when
 access the cache.

Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 client/filejsonstore/filejsonstore.go      | 82 +++++++++++++-------
 client/filejsonstore/filejsonstore_test.go | 88 +++++++++++++++++++---
 internal/fsutil/fsutil.go                  | 39 ++++++++++
 local_store.go                             |  5 +-
 util/util.go                               | 14 ----
 5 files changed, 174 insertions(+), 54 deletions(-)
 create mode 100644 internal/fsutil/fsutil.go

diff --git a/client/filejsonstore/filejsonstore.go b/client/filejsonstore/filejsonstore.go
index dd13651f..61442800 100644
--- a/client/filejsonstore/filejsonstore.go
+++ b/client/filejsonstore/filejsonstore.go
@@ -6,7 +6,9 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"sync"
 
+	"github.com/theupdateframework/go-tuf/internal/fsutil"
 	"github.com/theupdateframework/go-tuf/util"
 )
 
@@ -15,23 +17,33 @@ import (
 // (e.g. does not end in .json, case sensitive).
 var ErrNotJSON = errors.New("file is not in JSON format")
 
+// ErrToPermissive is returned when the metadata directory, or a metadata
+// file has too permissive file mode bits set
+var ErrTooPermissive = errors.New("permissions are too permissive")
+
+const (
+	// user:  rwx
+	// group: r-x
+	// other: ---
+	dirCreateMode = os.FileMode(0750)
+	// user:  rw-
+	// group: r--
+	// other: ---
+	fileCreateMode = os.FileMode(0640)
+)
+
 // FileJSONStore represents a local metadata cache relying on raw JSON files
 // as retrieved from the remote repository.
 type FileJSONStore struct {
+	mtx     sync.RWMutex
 	baseDir string
 }
 
 // NewFileJSONStore returns a new metadata cache, implemented using raw JSON
 // files, stored in a directory provided by the client.
 // If the provided directory does not exist on disk, it will be created.
-// The provided metadata cache is not safe for concurrent access, if
-// concurrent access safety is requires, wrap local store in a
-// ConcurrentLocalStore.
+// The provided metadata cache is afe for concurrent access
 func NewFileJSONStore(baseDir string) (*FileJSONStore, error) {
-	return newImpl(baseDir, true)
-}
-
-func newImpl(baseDir string, recurse bool) (*FileJSONStore, error) {
 	var f = FileJSONStore{
 		baseDir: baseDir,
 	}
@@ -41,22 +53,24 @@ func newImpl(baseDir string, recurse bool) (*FileJSONStore, error) {
 	fi, err := os.Stat(baseDir)
 	if err != nil {
 		pe, ok := err.(*os.PathError)
-		if ok && errors.Is(pe.Err, os.ErrNotExist) && recurse {
+		if ok && errors.Is(pe.Err, os.ErrNotExist) {
 			// Create the directory
-			// user:  rwx
-			// group: r-x
-			// other: ---
-			err = os.MkdirAll(baseDir, 0750)
-			if err == nil {
-				return newImpl(baseDir, false)
+			if err = os.MkdirAll(baseDir, dirCreateMode); err != nil {
+				return nil, err
 			}
+		} else {
+			return nil, err
+		}
+	} else {
+		// Verify that it is a directory
+		if !fi.IsDir() {
+			return nil, fmt.Errorf("can not open %s, not a directory",
+				baseDir)
+		}
+		// Verify file mode is not too permissive.
+		if err = fsutil.EnsurePermission(fi, dirCreateMode); err != nil {
+			return nil, ErrTooPermissive
 		}
-		return nil, err
-	}
-
-	if !fi.IsDir() {
-		return nil, fmt.Errorf("can not open %s, not a directory",
-			baseDir)
 	}
 
 	return &f, nil
@@ -64,6 +78,9 @@ func newImpl(baseDir string, recurse bool) (*FileJSONStore, error) {
 
 // GetMeta returns the currently cached set of metadata files.
 func (f *FileJSONStore) GetMeta() (map[string]json.RawMessage, error) {
+	f.mtx.RLock()
+	defer f.mtx.RUnlock()
+
 	names, err := os.ReadDir(f.baseDir)
 	if err != nil {
 		return nil, err
@@ -72,11 +89,21 @@ func (f *FileJSONStore) GetMeta() (map[string]json.RawMessage, error) {
 	meta := map[string]json.RawMessage{}
 	for _, name := range names {
 		p := filepath.FromSlash(filepath.Join(f.baseDir, name.Name()))
-		if ok, err := util.IsMetaFile(name); !ok {
+		ok, err := fsutil.IsMetaFile(name)
+		if err != nil {
+			return nil, err
+		}
+		if !ok {
 			continue
-		} else if err != nil {
+		}
+		// Verify permissions
+		info, err := name.Info()
+		if err != nil {
 			return nil, err
 		}
+		if err = fsutil.EnsurePermission(info, fileCreateMode); err != nil {
+			return nil, ErrTooPermissive
+		}
 		b, err := os.ReadFile(p)
 		if err != nil {
 			return nil, err
@@ -90,21 +117,24 @@ func (f *FileJSONStore) GetMeta() (map[string]json.RawMessage, error) {
 // SetMeta stores a metadata file in the cache. If the metadata file exist,
 // it will be overwritten.
 func (f *FileJSONStore) SetMeta(name string, meta json.RawMessage) error {
+	f.mtx.Lock()
+	defer f.mtx.Unlock()
+
 	if filepath.Ext(name) != ".json" {
 		return ErrNotJSON
 	}
 
 	p := filepath.FromSlash(filepath.Join(f.baseDir, name))
-	// user:  rw-
-	// group: r--
-	// other: ---
-	err := util.AtomicallyWriteFile(p, meta, 0640)
+	err := util.AtomicallyWriteFile(p, meta, fileCreateMode)
 	return err
 }
 
 // DeleteMeta deletes a metadata file from the cache.
 // If the file does not exist, an *os.PathError is returned.
 func (f *FileJSONStore) DeleteMeta(name string) error {
+	f.mtx.Lock()
+	defer f.mtx.Unlock()
+
 	if filepath.Ext(name) != ".json" {
 		return ErrNotJSON
 	}
diff --git a/client/filejsonstore/filejsonstore_test.go b/client/filejsonstore/filejsonstore_test.go
index 8fb4ece6..dfc54a62 100644
--- a/client/filejsonstore/filejsonstore_test.go
+++ b/client/filejsonstore/filejsonstore_test.go
@@ -13,14 +13,14 @@ import (
 	"github.com/theupdateframework/go-tuf/client"
 )
 
-type RawJSONStoreSuite struct{}
+type FileJSONStoreSuite struct{}
 
-var _ = check.Suite(&RawJSONStoreSuite{})
+var _ = check.Suite(&FileJSONStoreSuite{})
 
 // Hook up gocheck into the "go test" runner
 func Test(t *testing.T) { check.TestingT(t) }
 
-func (RawJSONStoreSuite) TestNewOk(c *check.C) {
+func (FileJSONStoreSuite) TestNewOk(c *check.C) {
 	tmp := c.MkDir()
 	p := filepath.Join(tmp, "tuf_raw.db")
 
@@ -41,7 +41,7 @@ func (RawJSONStoreSuite) TestNewOk(c *check.C) {
 	c.Assert(fi.IsDir(), check.Equals, true)
 }
 
-func (RawJSONStoreSuite) TestNewFileExists(c *check.C) {
+func (FileJSONStoreSuite) TestNewFileExists(c *check.C) {
 	tmp := c.MkDir()
 	p := filepath.Join(tmp, "tuf_raw.db")
 
@@ -58,7 +58,37 @@ func (RawJSONStoreSuite) TestNewFileExists(c *check.C) {
 	c.Assert(found, check.Equals, true)
 }
 
-func (RawJSONStoreSuite) TestGetMetaEmpty(c *check.C) {
+func (FileJSONStoreSuite) TestNewDirectoryExists(c *check.C) {
+	tmp := c.MkDir()
+	p := filepath.Join(tmp, "tuf_raw.db")
+
+	err := os.Mkdir(p, 0750)
+	c.Assert(err, check.IsNil)
+
+	// Create implementation
+	s, err := NewFileJSONStore(p)
+	c.Assert(s, check.NotNil)
+	c.Assert(err, check.IsNil)
+
+	// Modify the directory permission and try again
+	err = os.Chmod(p, 0751)
+	s, err = NewFileJSONStore(p)
+	c.Assert(s, check.IsNil)
+	c.Assert(err, check.Equals, ErrTooPermissive)
+}
+
+func (FileJSONStoreSuite) TestNewNoCreate(c *check.C) {
+	tmp := c.MkDir()
+	p := filepath.Join(tmp, "tuf_raw.db")
+
+	// Clear the write bit for the user
+	err := os.Chmod(tmp, 0551)
+	s, err := NewFileJSONStore(p)
+	c.Assert(s, check.IsNil)
+	c.Assert(err, check.NotNil)
+}
+
+func (FileJSONStoreSuite) TestGetMetaEmpty(c *check.C) {
 	tmp := c.MkDir()
 	p := filepath.Join(tmp, "tuf_raw.db")
 	s, err := NewFileJSONStore(p)
@@ -68,7 +98,20 @@ func (RawJSONStoreSuite) TestGetMetaEmpty(c *check.C) {
 	c.Assert(md, check.HasLen, 0)
 }
 
-func (RawJSONStoreSuite) TestMetadataOperations(c *check.C) {
+func (FileJSONStoreSuite) TestGetNoDirectory(c *check.C) {
+	tmp := c.MkDir()
+	p := filepath.Join(tmp, "tuf_raw.db")
+	s, err := NewFileJSONStore(p)
+
+	err = os.Remove(p)
+	c.Assert(err, check.IsNil)
+
+	md, err := s.GetMeta()
+	c.Assert(md, check.IsNil)
+	c.Assert(err, check.NotNil)
+}
+
+func (FileJSONStoreSuite) TestMetadataOperations(c *check.C) {
 	tmp := c.MkDir()
 	p := filepath.Join(tmp, "tuf_raw.db")
 	s, err := NewFileJSONStore(p)
@@ -104,7 +147,7 @@ func (RawJSONStoreSuite) TestMetadataOperations(c *check.C) {
 	c.Assert(md, check.HasLen, 0)
 }
 
-func (RawJSONStoreSuite) TestGetNoJSON(c *check.C) {
+func (FileJSONStoreSuite) TestGetNoJSON(c *check.C) {
 	tmp := c.MkDir()
 	p := filepath.Join(tmp, "tuf_raw.db")
 	s, err := NewFileJSONStore(p)
@@ -113,14 +156,32 @@ func (RawJSONStoreSuite) TestGetNoJSON(c *check.C) {
 
 	// Create a file which does not end with '.json'
 	fp := filepath.FromSlash(filepath.Join(p, "meta.xml"))
-	os.WriteFile(fp, []byte{}, 0644)
+	err = os.WriteFile(fp, []byte{}, 0644)
+	c.Assert(err, check.IsNil)
 
 	md, err := s.GetMeta()
 	c.Assert(err, check.IsNil)
 	c.Assert(md, check.HasLen, 0)
 }
 
-func (RawJSONStoreSuite) TestNoJSON(c *check.C) {
+func (FileJSONStoreSuite) TestGetTooPermissive(c *check.C) {
+	tmp := c.MkDir()
+	p := filepath.Join(tmp, "tuf_raw.db")
+	s, err := NewFileJSONStore(p)
+	c.Assert(s, check.NotNil)
+	c.Assert(err, check.IsNil)
+
+	// Create a file which does not end with '.json'
+	fp := filepath.FromSlash(filepath.Join(p, "meta.json"))
+	err = os.WriteFile(fp, []byte{}, 0644)
+	c.Assert(err, check.IsNil)
+
+	md, err := s.GetMeta()
+	c.Assert(md, check.IsNil)
+	c.Assert(err, check.Equals, ErrTooPermissive)
+}
+
+func (FileJSONStoreSuite) TestNoJSON(c *check.C) {
 	tmp := c.MkDir()
 	p := filepath.Join(tmp, "tuf_raw.db")
 	s, err := NewFileJSONStore(p)
@@ -138,7 +199,7 @@ func (RawJSONStoreSuite) TestNoJSON(c *check.C) {
 	}
 }
 
-func (RawJSONStoreSuite) TestClose(c *check.C) {
+func (FileJSONStoreSuite) TestClose(c *check.C) {
 	tmp := c.MkDir()
 	p := filepath.Join(tmp, "tuf_raw.db")
 	s, err := NewFileJSONStore(p)
@@ -149,7 +210,7 @@ func (RawJSONStoreSuite) TestClose(c *check.C) {
 	c.Assert(err, check.IsNil)
 }
 
-func (RawJSONStoreSuite) TestDelete(c *check.C) {
+func (FileJSONStoreSuite) TestDelete(c *check.C) {
 	tmp := c.MkDir()
 	p := filepath.Join(tmp, "tuf_raw.db")
 	s, err := NewFileJSONStore(p)
@@ -162,7 +223,7 @@ func (RawJSONStoreSuite) TestDelete(c *check.C) {
 	c.Assert(errors.Is(err, os.ErrNotExist), check.Equals, true)
 }
 
-func (RawJSONStoreSuite) TestInterface(c *check.C) {
+func (FileJSONStoreSuite) TestInterface(c *check.C) {
 	var localStore client.LocalStore
 	var err error
 
@@ -172,3 +233,6 @@ func (RawJSONStoreSuite) TestInterface(c *check.C) {
 	c.Assert(localStore, check.NotNil)
 	c.Assert(err, check.IsNil)
 }
+
+// test 3 file exist and is too permissive
+// test 4 remote base dir after create
diff --git a/internal/fsutil/fsutil.go b/internal/fsutil/fsutil.go
new file mode 100644
index 00000000..98883952
--- /dev/null
+++ b/internal/fsutil/fsutil.go
@@ -0,0 +1,39 @@
+// Package fsutil defiens a set of internal utility functions used to
+// interact with the file system.
+package fsutil
+
+import (
+	"errors"
+	"io/fs"
+	"os"
+	"path/filepath"
+)
+
+var ErrPermission = errors.New("unexpected permission")
+
+// IsMetaFile tests wheter a DirEntry appears to be a metaddata file or not.
+func IsMetaFile(e os.DirEntry) (bool, error) {
+	if e.IsDir() || filepath.Ext(e.Name()) != ".json" {
+		return false, nil
+	}
+
+	info, err := e.Info()
+	if err != nil {
+		return false, err
+	}
+
+	return info.Mode().IsRegular(), nil
+}
+
+// EnsurePemissions tests the provided file info to make sure the
+// permission bits matches the provided.
+func EnsurePermission(fi os.FileInfo, perm os.FileMode) error {
+	// Clear all bits which are note related to the permission.
+	mode := fi.Mode() & fs.ModePerm
+	mask := ^perm
+	if (mode & mask) != 0 {
+		return ErrPermission
+	}
+
+	return nil
+}
diff --git a/local_store.go b/local_store.go
index 86aed2c9..1409f13f 100644
--- a/local_store.go
+++ b/local_store.go
@@ -14,6 +14,7 @@ import (
 
 	"github.com/theupdateframework/go-tuf/data"
 	"github.com/theupdateframework/go-tuf/encrypted"
+	"github.com/theupdateframework/go-tuf/internal/fsutil"
 	"github.com/theupdateframework/go-tuf/internal/sets"
 	"github.com/theupdateframework/go-tuf/pkg/keys"
 	"github.com/theupdateframework/go-tuf/util"
@@ -234,7 +235,7 @@ func (f *fileSystemStore) GetMeta() (map[string]json.RawMessage, error) {
 	}
 
 	for _, e := range committed {
-		imf, err := util.IsMetaFile(e)
+		imf, err := fsutil.IsMetaFile(e)
 		if err != nil {
 			return nil, err
 		}
@@ -251,7 +252,7 @@ func (f *fileSystemStore) GetMeta() (map[string]json.RawMessage, error) {
 	}
 
 	for _, e := range staged {
-		imf, err := util.IsMetaFile(e)
+		imf, err := fsutil.IsMetaFile(e)
 		if err != nil {
 			return nil, err
 		}
diff --git a/util/util.go b/util/util.go
index dfcb67f3..0878c823 100644
--- a/util/util.go
+++ b/util/util.go
@@ -331,17 +331,3 @@ func AtomicallyWriteFile(filename string, data []byte, perm os.FileMode) error {
 
 	return nil
 }
-
-// IsMetaFile tests wheter a DirEntry appears to be a metaddata file or not.
-func IsMetaFile(e os.DirEntry) (bool, error) {
-	if e.IsDir() || filepath.Ext(e.Name()) != ".json" {
-		return false, nil
-	}
-
-	info, err := e.Info()
-	if err != nil {
-		return false, err
-	}
-
-	return info.Mode().IsRegular(), nil
-}

From 83c0eab250002efead52520d00367d7eea8f18d1 Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Thu, 11 Aug 2022 15:42:46 +0200
Subject: [PATCH 16/43] Spelling error.

Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 client/filejsonstore/filejsonstore.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/client/filejsonstore/filejsonstore.go b/client/filejsonstore/filejsonstore.go
index 61442800..90cfe24f 100644
--- a/client/filejsonstore/filejsonstore.go
+++ b/client/filejsonstore/filejsonstore.go
@@ -42,7 +42,7 @@ type FileJSONStore struct {
 // NewFileJSONStore returns a new metadata cache, implemented using raw JSON
 // files, stored in a directory provided by the client.
 // If the provided directory does not exist on disk, it will be created.
-// The provided metadata cache is afe for concurrent access
+// The provided metadata cache is safe for concurrent access.
 func NewFileJSONStore(baseDir string) (*FileJSONStore, error) {
 	var f = FileJSONStore{
 		baseDir: baseDir,

From 0cbf33235c7ee150778c3991f9f84af05e44bb4c Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Fri, 12 Aug 2022 07:37:51 +0200
Subject: [PATCH 17/43] Updates based on PR comments. Removed a test for
 satisfying an interface, and replaced with a compile time check.

Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 client/filejsonstore/filejsonstore.go      |  3 +++
 client/filejsonstore/filejsonstore_test.go | 16 ----------------
 2 files changed, 3 insertions(+), 16 deletions(-)

diff --git a/client/filejsonstore/filejsonstore.go b/client/filejsonstore/filejsonstore.go
index 90cfe24f..c80d8ede 100644
--- a/client/filejsonstore/filejsonstore.go
+++ b/client/filejsonstore/filejsonstore.go
@@ -8,6 +8,7 @@ import (
 	"path/filepath"
 	"sync"
 
+	"github.com/theupdateframework/go-tuf/client"
 	"github.com/theupdateframework/go-tuf/internal/fsutil"
 	"github.com/theupdateframework/go-tuf/util"
 )
@@ -39,6 +40,8 @@ type FileJSONStore struct {
 	baseDir string
 }
 
+var _ client.LocalStore = (*FileJSONStore)(nil)
+
 // NewFileJSONStore returns a new metadata cache, implemented using raw JSON
 // files, stored in a directory provided by the client.
 // If the provided directory does not exist on disk, it will be created.
diff --git a/client/filejsonstore/filejsonstore_test.go b/client/filejsonstore/filejsonstore_test.go
index dfc54a62..1fdc4e8b 100644
--- a/client/filejsonstore/filejsonstore_test.go
+++ b/client/filejsonstore/filejsonstore_test.go
@@ -9,8 +9,6 @@ import (
 	"testing"
 
 	"gopkg.in/check.v1"
-
-	"github.com/theupdateframework/go-tuf/client"
 )
 
 type FileJSONStoreSuite struct{}
@@ -222,17 +220,3 @@ func (FileJSONStoreSuite) TestDelete(c *check.C) {
 	err = s.DeleteMeta("non_existing.json")
 	c.Assert(errors.Is(err, os.ErrNotExist), check.Equals, true)
 }
-
-func (FileJSONStoreSuite) TestInterface(c *check.C) {
-	var localStore client.LocalStore
-	var err error
-
-	tmp := c.MkDir()
-	p := filepath.Join(tmp, "tuf_raw.db")
-	localStore, err = NewFileJSONStore(p)
-	c.Assert(localStore, check.NotNil)
-	c.Assert(err, check.IsNil)
-}
-
-// test 3 file exist and is too permissive
-// test 4 remote base dir after create

From 7a935d6f4cfbd9e16995644232781e88d450ba3a Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Thu, 28 Jul 2022 16:57:44 +0200
Subject: [PATCH 18/43] Added first draft for a raw json local file storage.

Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 client/filejsonstore/filejsonstore.go | 95 +++++++++++++++++++++++++++
 1 file changed, 95 insertions(+)
 create mode 100644 client/filejsonstore/filejsonstore.go

diff --git a/client/filejsonstore/filejsonstore.go b/client/filejsonstore/filejsonstore.go
new file mode 100644
index 00000000..1a963112
--- /dev/null
+++ b/client/filejsonstore/filejsonstore.go
@@ -0,0 +1,95 @@
+package filejsonstore
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+)
+
+type FileJSONStore struct {
+	f       *os.File
+	baseDir string
+}
+
+func New(baseDir string) (*FileJSONStore, error) {
+	return newImpl(baseDir, true)
+}
+
+func newImpl(baseDir string, recurse bool) (*FileJSONStore, error) {
+	var f = FileJSONStore{
+		baseDir: baseDir,
+	}
+	var err error
+
+	if f.f, err = os.Open(baseDir); err != nil {
+		pe, ok := err.(*os.PathError)
+		fmt.Println(ok)
+		fmt.Println(pe.Err)
+		if ok && errors.Is(pe.Err, os.ErrNotExist) && recurse {
+			// Create the directory
+			err = os.Mkdir(baseDir, 0750)
+			if err == nil {
+				return newImpl(baseDir, false)
+			}
+			return nil, err
+		} else {
+			return nil, err
+		}
+	}
+
+	if stat, err := f.f.Stat(); err != nil {
+		f.f.Close()
+		return nil, fmt.Errorf("failed to stat file %s: %w",
+			baseDir, err)
+	} else {
+		if !stat.IsDir() {
+			f.f.Close()
+			return nil, fmt.Errorf("can not open %s, not a directory",
+				baseDir)
+		}
+	}
+
+	return &f, nil
+}
+
+func (f *FileJSONStore) GetMeta() (map[string]json.RawMessage, error) {
+	names, err := f.f.Readdirnames(0)
+
+	if err != nil {
+		return nil, err
+	}
+
+	meta := map[string]json.RawMessage{}
+	for _, name := range names {
+		p := filepath.FromSlash(filepath.Join(f.baseDir, name))
+		b, err := os.ReadFile(p)
+		if err != nil {
+			return nil, err
+		}
+		meta[name] = b
+	}
+
+	return meta, nil
+}
+
+func (f *FileJSONStore) SetMeta(name string, meta json.RawMessage) error {
+	p := filepath.FromSlash(filepath.Join(f.baseDir, name))
+	return os.WriteFile(p, meta, 0640)
+}
+
+func (f *FileJSONStore) DeleteMeta(name string) error {
+	p := filepath.FromSlash(filepath.Join(f.baseDir, name))
+	return os.Remove(p)
+}
+
+func (f *FileJSONStore) Close() error {
+	if f == nil {
+		return nil
+	}
+	if f.f != nil {
+		return f.f.Close()
+	}
+	return nil
+}

From c0cc5fcacf0d9443f1997048f988ff2a050fcac4 Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Thu, 28 Jul 2022 16:58:23 +0200
Subject: [PATCH 19/43] Ignore emacs temporary files

Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 .gitignore | 1 +
 1 file changed, 1 insertion(+)

diff --git a/.gitignore b/.gitignore
index 64b8f8a8..39e7149c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,3 +2,4 @@
 cmd/tuf/tuf
 cmd/tuf-client/tuf-client
 .vscode
+*~

From ad8f340de1b04ec789ee6a8ec37c908826707129 Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Fri, 29 Jul 2022 13:35:49 +0200
Subject: [PATCH 20/43] moved isMetaFile to util directory for reuse in other
 packages.

Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 local_store.go | 17 ++---------------
 util/util.go   | 14 ++++++++++++++
 2 files changed, 16 insertions(+), 15 deletions(-)

diff --git a/local_store.go b/local_store.go
index 9fd95dc5..86aed2c9 100644
--- a/local_store.go
+++ b/local_store.go
@@ -222,19 +222,6 @@ func (f *fileSystemStore) stagedDir() string {
 	return filepath.Join(f.dir, "staged")
 }
 
-func isMetaFile(e os.DirEntry) (bool, error) {
-	if e.IsDir() || filepath.Ext(e.Name()) != ".json" {
-		return false, nil
-	}
-
-	info, err := e.Info()
-	if err != nil {
-		return false, err
-	}
-
-	return info.Mode().IsRegular(), nil
-}
-
 func (f *fileSystemStore) GetMeta() (map[string]json.RawMessage, error) {
 	// Build a map of metadata names (e.g. root.json) to their full paths
 	// (whether in the committed repo dir, or in the staged repo dir).
@@ -247,7 +234,7 @@ func (f *fileSystemStore) GetMeta() (map[string]json.RawMessage, error) {
 	}
 
 	for _, e := range committed {
-		imf, err := isMetaFile(e)
+		imf, err := util.IsMetaFile(e)
 		if err != nil {
 			return nil, err
 		}
@@ -264,7 +251,7 @@ func (f *fileSystemStore) GetMeta() (map[string]json.RawMessage, error) {
 	}
 
 	for _, e := range staged {
-		imf, err := isMetaFile(e)
+		imf, err := util.IsMetaFile(e)
 		if err != nil {
 			return nil, err
 		}
diff --git a/util/util.go b/util/util.go
index 0878c823..dfcb67f3 100644
--- a/util/util.go
+++ b/util/util.go
@@ -331,3 +331,17 @@ func AtomicallyWriteFile(filename string, data []byte, perm os.FileMode) error {
 
 	return nil
 }
+
+// IsMetaFile tests wheter a DirEntry appears to be a metaddata file or not.
+func IsMetaFile(e os.DirEntry) (bool, error) {
+	if e.IsDir() || filepath.Ext(e.Name()) != ".json" {
+		return false, nil
+	}
+
+	info, err := e.Info()
+	if err != nil {
+		return false, err
+	}
+
+	return info.Mode().IsRegular(), nil
+}

From d1956d6ce5db774086a5c859ca1c2a80a2cff623 Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Fri, 29 Jul 2022 13:36:49 +0200
Subject: [PATCH 21/43] Added unit tests and refactored code to match the local
 store for repository side.

Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 client/filejsonstore/filejsonstore.go      |  61 +++++-----
 client/filejsonstore/filejsonstore_test.go | 132 +++++++++++++++++++++
 2 files changed, 165 insertions(+), 28 deletions(-)
 create mode 100644 client/filejsonstore/filejsonstore_test.go

diff --git a/client/filejsonstore/filejsonstore.go b/client/filejsonstore/filejsonstore.go
index 1a963112..e48ce3c1 100644
--- a/client/filejsonstore/filejsonstore.go
+++ b/client/filejsonstore/filejsonstore.go
@@ -6,10 +6,13 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+
+	"github.com/theupdateframework/go-tuf/util"
 )
 
+var ErrNotJSON = errors.New("file is not in JSON format")
+
 type FileJSONStore struct {
-	f       *os.File
 	baseDir string
 }
 
@@ -23,39 +26,33 @@ func newImpl(baseDir string, recurse bool) (*FileJSONStore, error) {
 	}
 	var err error
 
-	if f.f, err = os.Open(baseDir); err != nil {
+	// Does the directory exist?
+	fi, err := os.Stat(baseDir)
+	if err != nil {
 		pe, ok := err.(*os.PathError)
-		fmt.Println(ok)
-		fmt.Println(pe.Err)
 		if ok && errors.Is(pe.Err, os.ErrNotExist) && recurse {
 			// Create the directory
+			// user:  rwx
+			// group: r-x
+			// other: ---
 			err = os.Mkdir(baseDir, 0750)
 			if err == nil {
 				return newImpl(baseDir, false)
 			}
-			return nil, err
-		} else {
-			return nil, err
 		}
+		return nil, err
 	}
 
-	if stat, err := f.f.Stat(); err != nil {
-		f.f.Close()
-		return nil, fmt.Errorf("failed to stat file %s: %w",
-			baseDir, err)
-	} else {
-		if !stat.IsDir() {
-			f.f.Close()
-			return nil, fmt.Errorf("can not open %s, not a directory",
-				baseDir)
-		}
+	if !fi.IsDir() {
+		return nil, fmt.Errorf("can not open %s, not a directory",
+			baseDir)
 	}
 
 	return &f, nil
 }
 
 func (f *FileJSONStore) GetMeta() (map[string]json.RawMessage, error) {
-	names, err := f.f.Readdirnames(0)
+	names, err := os.ReadDir(f.baseDir)
 
 	if err != nil {
 		return nil, err
@@ -63,33 +60,41 @@ func (f *FileJSONStore) GetMeta() (map[string]json.RawMessage, error) {
 
 	meta := map[string]json.RawMessage{}
 	for _, name := range names {
-		p := filepath.FromSlash(filepath.Join(f.baseDir, name))
+		p := filepath.FromSlash(filepath.Join(f.baseDir, name.Name()))
+		if ok, err := util.IsMetaFile(name); !ok {
+			continue
+		} else if err != nil {
+			return nil, err
+		}
 		b, err := os.ReadFile(p)
 		if err != nil {
 			return nil, err
 		}
-		meta[name] = b
+		meta[name.Name()] = b
 	}
 
 	return meta, nil
 }
 
 func (f *FileJSONStore) SetMeta(name string, meta json.RawMessage) error {
+	if filepath.Ext(name) != ".json" {
+		return ErrNotJSON
+	}
+
 	p := filepath.FromSlash(filepath.Join(f.baseDir, name))
-	return os.WriteFile(p, meta, 0640)
+	// user:  rw-
+	// group: r--
+	// other: ---
+	err := util.AtomicallyWriteFile(p, meta, 0640)
+	return err
 }
 
 func (f *FileJSONStore) DeleteMeta(name string) error {
 	p := filepath.FromSlash(filepath.Join(f.baseDir, name))
-	return os.Remove(p)
+	err := os.Remove(p)
+	return err
 }
 
 func (f *FileJSONStore) Close() error {
-	if f == nil {
-		return nil
-	}
-	if f.f != nil {
-		return f.f.Close()
-	}
 	return nil
 }
diff --git a/client/filejsonstore/filejsonstore_test.go b/client/filejsonstore/filejsonstore_test.go
new file mode 100644
index 00000000..65fc73a8
--- /dev/null
+++ b/client/filejsonstore/filejsonstore_test.go
@@ -0,0 +1,132 @@
+package filejsonstore
+
+import (
+	"encoding/json"
+	"errors"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"gopkg.in/check.v1"
+)
+
+type RawJSONStoreSuite struct{}
+
+var _ = check.Suite(&RawJSONStoreSuite{})
+
+// Hook up gocheck into the "go test" runnder
+func Test(t *testing.T) { check.TestingT(t) }
+
+func (RawJSONStoreSuite) TestNewOk(c *check.C) {
+	tmp := c.MkDir()
+	p := filepath.Join(tmp, "tuf_raw.db")
+
+	// Assert path does not exist
+	fi, err := os.Stat(p)
+	c.Assert(fi, check.IsNil)
+	c.Assert(errors.Is(err, os.ErrNotExist), check.Equals, true)
+
+	// Create implementation
+	s, err := New(p)
+	c.Assert(err, check.IsNil)
+	c.Assert(s, check.NotNil)
+
+	// Assert path does exist and is a directory
+	fi, err = os.Stat(p)
+	c.Assert(fi, check.NotNil)
+	c.Assert(err, check.IsNil)
+	c.Assert(fi.IsDir(), check.Equals, true)
+}
+
+func (RawJSONStoreSuite) TestNewFileExists(c *check.C) {
+	tmp := c.MkDir()
+	p := filepath.Join(tmp, "tuf_raw.db")
+
+	// Create an empty file
+	f, err := os.Create(p)
+	c.Assert(err, check.IsNil)
+	f.Close()
+
+	// Create implementation
+	s, err := New(p)
+	c.Assert(s, check.IsNil)
+	c.Assert(err, check.NotNil)
+	found := strings.Contains(err.Error(), ", not a directory")
+	c.Assert(found, check.Equals, true)
+}
+
+func (RawJSONStoreSuite) TestGetMetaEmpty(c *check.C) {
+	tmp := c.MkDir()
+	p := filepath.Join(tmp, "tuf_raw.db")
+	s, err := New(p)
+
+	md, err := s.GetMeta()
+	c.Assert(err, check.IsNil)
+	c.Assert(md, check.HasLen, 0)
+}
+
+func (RawJSONStoreSuite) TestMetadataOperations(c *check.C) {
+	tmp := c.MkDir()
+	p := filepath.Join(tmp, "tuf_raw.db")
+	s, err := New(p)
+	expected := map[string]json.RawMessage{
+		"file1.json": []byte{0xf1, 0xe1, 0xd1},
+		"file2.json": []byte{0xf2, 0xe2, 0xd2},
+		"file3.json": []byte{0xf3, 0xe3, 0xd3},
+	}
+
+	for k, v := range expected {
+		s.SetMeta(k, v)
+	}
+
+	md, err := s.GetMeta()
+	c.Assert(err, check.IsNil)
+	c.Assert(md, check.HasLen, 3)
+	c.Assert(md, check.DeepEquals, expected)
+
+	// Nuke items
+	count := 3
+	for k := range expected {
+		err = s.DeleteMeta(k)
+		count--
+		c.Assert(err, check.IsNil)
+		md, err := s.GetMeta()
+		c.Assert(err, check.IsNil)
+		c.Assert(md, check.HasLen, count)
+	}
+
+	md, err = s.GetMeta()
+	c.Assert(err, check.IsNil)
+	c.Assert(md, check.HasLen, 0)
+}
+
+func (RawJSONStoreSuite) TestNoJSON(c *check.C) {
+	tmp := c.MkDir()
+	p := filepath.Join(tmp, "tuf_raw.db")
+	s, err := New(p)
+	c.Assert(s, check.NotNil)
+	c.Assert(err, check.IsNil)
+
+	files := []string{
+		"file.xml",
+		"file",
+		"",
+	}
+	for _, f := range files {
+		err := s.SetMeta(f, []byte{})
+		c.Assert(err, check.Equals, ErrNotJSON)
+	}
+
+}
+
+func (RawJSONStoreSuite) TestClose(c *check.C) {
+	tmp := c.MkDir()
+	p := filepath.Join(tmp, "tuf_raw.db")
+	s, err := New(p)
+	c.Assert(s, check.NotNil)
+	c.Assert(err, check.IsNil)
+
+	err = s.Close()
+	c.Assert(err, check.IsNil)
+}

From 678b7f9c30f449f4a9b9a569b836001f61e168d1 Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Fri, 29 Jul 2022 14:09:34 +0200
Subject: [PATCH 22/43] Added test case for non json file in metadata
 directory. Changed package to client to align with leveldb storage.

Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 client/filejsonstore/filejsonstore.go      |  2 +-
 client/filejsonstore/filejsonstore_test.go | 18 +++++++++++++++++-
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/client/filejsonstore/filejsonstore.go b/client/filejsonstore/filejsonstore.go
index e48ce3c1..15943886 100644
--- a/client/filejsonstore/filejsonstore.go
+++ b/client/filejsonstore/filejsonstore.go
@@ -1,4 +1,4 @@
-package filejsonstore
+package client
 
 import (
 	"encoding/json"
diff --git a/client/filejsonstore/filejsonstore_test.go b/client/filejsonstore/filejsonstore_test.go
index 65fc73a8..5577aab6 100644
--- a/client/filejsonstore/filejsonstore_test.go
+++ b/client/filejsonstore/filejsonstore_test.go
@@ -1,4 +1,4 @@
-package filejsonstore
+package client
 
 import (
 	"encoding/json"
@@ -101,6 +101,22 @@ func (RawJSONStoreSuite) TestMetadataOperations(c *check.C) {
 	c.Assert(md, check.HasLen, 0)
 }
 
+func (RawJSONStoreSuite) TestGetNoJSON(c *check.C) {
+	tmp := c.MkDir()
+	p := filepath.Join(tmp, "tuf_raw.db")
+	s, err := New(p)
+	c.Assert(s, check.NotNil)
+	c.Assert(err, check.IsNil)
+
+	// Create a file which does not end with '.json'
+	fp := filepath.FromSlash(filepath.Join(p, "meta.xml"))
+	os.WriteFile(fp, []byte{}, 0644)
+
+	md, err := s.GetMeta()
+	c.Assert(err, check.IsNil)
+	c.Assert(md, check.HasLen, 0)
+}
+
 func (RawJSONStoreSuite) TestNoJSON(c *check.C) {
 	tmp := c.MkDir()
 	p := filepath.Join(tmp, "tuf_raw.db")

From 207fb70a2ad0a5a3f593889d36e663fcee8e44d8 Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Fri, 29 Jul 2022 15:33:37 +0200
Subject: [PATCH 23/43] Use os.MkdirAll when creating metadata cache.

Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 client/filejsonstore/filejsonstore.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/client/filejsonstore/filejsonstore.go b/client/filejsonstore/filejsonstore.go
index 15943886..c2c7a42e 100644
--- a/client/filejsonstore/filejsonstore.go
+++ b/client/filejsonstore/filejsonstore.go
@@ -35,7 +35,7 @@ func newImpl(baseDir string, recurse bool) (*FileJSONStore, error) {
 			// user:  rwx
 			// group: r-x
 			// other: ---
-			err = os.Mkdir(baseDir, 0750)
+			err = os.MkdirAll(baseDir, 0750)
 			if err == nil {
 				return newImpl(baseDir, false)
 			}

From 7916ddf9654bd875590de375aaf09693b8400bf4 Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Mon, 1 Aug 2022 08:35:45 +0200
Subject: [PATCH 24/43] More consistent naming, added comments and a unit test.

Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 client/filejsonstore/filejsonstore.go      | 21 ++++++++++++++++-
 client/filejsonstore/filejsonstore_test.go | 27 ++++++++++++++++------
 2 files changed, 40 insertions(+), 8 deletions(-)

diff --git a/client/filejsonstore/filejsonstore.go b/client/filejsonstore/filejsonstore.go
index c2c7a42e..fb9493e7 100644
--- a/client/filejsonstore/filejsonstore.go
+++ b/client/filejsonstore/filejsonstore.go
@@ -10,13 +10,22 @@ import (
 	"github.com/theupdateframework/go-tuf/util"
 )
 
+// ErrNotJSON is returned when a metadata operation is attempted to be
+// performed against a file that does not seem to be a JSON file
+// (e.g. does not end in .json, case sensitive).
 var ErrNotJSON = errors.New("file is not in JSON format")
 
+// FileJSONStore represents a local metadata cache relying on raw JSON files
+// as retrieved from the remote repository.
 type FileJSONStore struct {
 	baseDir string
 }
 
-func New(baseDir string) (*FileJSONStore, error) {
+// NewFileJSONStore returns a new metadata cache, implemented using raw JSON
+// files, stored in a directory provided by the client.
+// If the provided directory does not exist on disk, it will be created.
+// The provided metadata cache is not safe for concurrent access.
+func NewFileJSONStore(baseDir string) (*FileJSONStore, error) {
 	return newImpl(baseDir, true)
 }
 
@@ -51,6 +60,7 @@ func newImpl(baseDir string, recurse bool) (*FileJSONStore, error) {
 	return &f, nil
 }
 
+// GetMeta returns the currently cached set of metadata files.
 func (f *FileJSONStore) GetMeta() (map[string]json.RawMessage, error) {
 	names, err := os.ReadDir(f.baseDir)
 
@@ -76,6 +86,8 @@ func (f *FileJSONStore) GetMeta() (map[string]json.RawMessage, error) {
 	return meta, nil
 }
 
+// SetMeta stores a metadata file in the cache. If the metadata file exist,
+// it will be overwritten.
 func (f *FileJSONStore) SetMeta(name string, meta json.RawMessage) error {
 	if filepath.Ext(name) != ".json" {
 		return ErrNotJSON
@@ -89,12 +101,19 @@ func (f *FileJSONStore) SetMeta(name string, meta json.RawMessage) error {
 	return err
 }
 
+// DeleteMeta deletes a metadata file from the cache.
+// If the file does not exist, an *os.PathError is returned.
 func (f *FileJSONStore) DeleteMeta(name string) error {
+	if filepath.Ext(name) != ".json" {
+		return ErrNotJSON
+	}
+
 	p := filepath.FromSlash(filepath.Join(f.baseDir, name))
 	err := os.Remove(p)
 	return err
 }
 
+// Close closes the metadata cache. This is a no-op.
 func (f *FileJSONStore) Close() error {
 	return nil
 }
diff --git a/client/filejsonstore/filejsonstore_test.go b/client/filejsonstore/filejsonstore_test.go
index 5577aab6..7a6a139c 100644
--- a/client/filejsonstore/filejsonstore_test.go
+++ b/client/filejsonstore/filejsonstore_test.go
@@ -28,7 +28,7 @@ func (RawJSONStoreSuite) TestNewOk(c *check.C) {
 	c.Assert(errors.Is(err, os.ErrNotExist), check.Equals, true)
 
 	// Create implementation
-	s, err := New(p)
+	s, err := NewFileJSONStore(p)
 	c.Assert(err, check.IsNil)
 	c.Assert(s, check.NotNil)
 
@@ -49,7 +49,7 @@ func (RawJSONStoreSuite) TestNewFileExists(c *check.C) {
 	f.Close()
 
 	// Create implementation
-	s, err := New(p)
+	s, err := NewFileJSONStore(p)
 	c.Assert(s, check.IsNil)
 	c.Assert(err, check.NotNil)
 	found := strings.Contains(err.Error(), ", not a directory")
@@ -59,7 +59,7 @@ func (RawJSONStoreSuite) TestNewFileExists(c *check.C) {
 func (RawJSONStoreSuite) TestGetMetaEmpty(c *check.C) {
 	tmp := c.MkDir()
 	p := filepath.Join(tmp, "tuf_raw.db")
-	s, err := New(p)
+	s, err := NewFileJSONStore(p)
 
 	md, err := s.GetMeta()
 	c.Assert(err, check.IsNil)
@@ -69,7 +69,7 @@ func (RawJSONStoreSuite) TestGetMetaEmpty(c *check.C) {
 func (RawJSONStoreSuite) TestMetadataOperations(c *check.C) {
 	tmp := c.MkDir()
 	p := filepath.Join(tmp, "tuf_raw.db")
-	s, err := New(p)
+	s, err := NewFileJSONStore(p)
 	expected := map[string]json.RawMessage{
 		"file1.json": []byte{0xf1, 0xe1, 0xd1},
 		"file2.json": []byte{0xf2, 0xe2, 0xd2},
@@ -104,7 +104,7 @@ func (RawJSONStoreSuite) TestMetadataOperations(c *check.C) {
 func (RawJSONStoreSuite) TestGetNoJSON(c *check.C) {
 	tmp := c.MkDir()
 	p := filepath.Join(tmp, "tuf_raw.db")
-	s, err := New(p)
+	s, err := NewFileJSONStore(p)
 	c.Assert(s, check.NotNil)
 	c.Assert(err, check.IsNil)
 
@@ -120,7 +120,7 @@ func (RawJSONStoreSuite) TestGetNoJSON(c *check.C) {
 func (RawJSONStoreSuite) TestNoJSON(c *check.C) {
 	tmp := c.MkDir()
 	p := filepath.Join(tmp, "tuf_raw.db")
-	s, err := New(p)
+	s, err := NewFileJSONStore(p)
 	c.Assert(s, check.NotNil)
 	c.Assert(err, check.IsNil)
 
@@ -139,10 +139,23 @@ func (RawJSONStoreSuite) TestNoJSON(c *check.C) {
 func (RawJSONStoreSuite) TestClose(c *check.C) {
 	tmp := c.MkDir()
 	p := filepath.Join(tmp, "tuf_raw.db")
-	s, err := New(p)
+	s, err := NewFileJSONStore(p)
 	c.Assert(s, check.NotNil)
 	c.Assert(err, check.IsNil)
 
 	err = s.Close()
 	c.Assert(err, check.IsNil)
 }
+
+func (RawJSONStoreSuite) TestDelete(c *check.C) {
+	tmp := c.MkDir()
+	p := filepath.Join(tmp, "tuf_raw.db")
+	s, err := NewFileJSONStore(p)
+	c.Assert(s, check.NotNil)
+	c.Assert(err, check.IsNil)
+
+	err = s.DeleteMeta("not_json.yml")
+	c.Assert(err, check.Equals, ErrNotJSON)
+	err = s.DeleteMeta("non_existing.json")
+	c.Assert(errors.Is(err, os.ErrNotExist), check.Equals, true)
+}

From ae6b3d8d9800d1f39f5d162110b7d4f1274bfe2c Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Thu, 4 Aug 2022 08:12:46 +0200
Subject: [PATCH 25/43] Added a localstore wrapper for concurrent access.

Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 client/concurrentlocalstore.go             | 49 +++++++++++++++++++
 client/concurrentlocalstore_test.go        | 55 ++++++++++++++++++++++
 client/filejsonstore/filejsonstore.go      |  4 +-
 client/filejsonstore/filejsonstore_test.go |  3 +-
 4 files changed, 109 insertions(+), 2 deletions(-)
 create mode 100644 client/concurrentlocalstore.go
 create mode 100644 client/concurrentlocalstore_test.go

diff --git a/client/concurrentlocalstore.go b/client/concurrentlocalstore.go
new file mode 100644
index 00000000..f37f7aa1
--- /dev/null
+++ b/client/concurrentlocalstore.go
@@ -0,0 +1,49 @@
+package client
+
+import (
+	"encoding/json"
+	"sync"
+)
+
+// ConcurrentLocalStore provides a LocalStore over an existing LocalStore
+// implementation that is safe for concurrent access.
+type ConcurrentLocalStore struct {
+	mtx   sync.RWMutex
+	store LocalStore
+}
+
+// NewConcurrentLocalStore returns a wrapped LocalStore that is safe for
+// concurrent access.
+func NewConcurrentLocalStore(s LocalStore) *ConcurrentLocalStore {
+	return &ConcurrentLocalStore{
+		store: s,
+	}
+}
+
+// GetMeta returns all known targets.
+func (c *ConcurrentLocalStore) GetMeta() (map[string]json.RawMessage, error) {
+	c.mtx.RLock()
+	defer c.mtx.RUnlock()
+	return c.store.GetMeta()
+}
+
+// SetMeta updates the lcoal store with a new target.
+func (c *ConcurrentLocalStore) SetMeta(name string, meta json.RawMessage) error {
+	c.mtx.Lock()
+	defer c.mtx.Unlock()
+	return c.store.SetMeta(name, meta)
+}
+
+// DeleteMeta remves a target from the cache.
+func (c *ConcurrentLocalStore) DeleteMeta(name string) error {
+	c.mtx.Lock()
+	defer c.mtx.Unlock()
+	return c.store.DeleteMeta(name)
+}
+
+// Close closes the local store.
+func (c *ConcurrentLocalStore) Close() error {
+	c.mtx.Lock()
+	defer c.mtx.Unlock()
+	return c.store.Close()
+}
diff --git a/client/concurrentlocalstore_test.go b/client/concurrentlocalstore_test.go
new file mode 100644
index 00000000..4c883f23
--- /dev/null
+++ b/client/concurrentlocalstore_test.go
@@ -0,0 +1,55 @@
+package client
+
+import (
+	"encoding/json"
+	"testing"
+
+	"gopkg.in/check.v1"
+)
+
+type ConcurrentStoreSuite struct{}
+
+var _ = check.Suite(&ConcurrentStoreSuite{})
+
+// Hook up gocheck into the "go test" runnder
+func ConcurrentTest(t *testing.T) { check.TestingT(t) }
+
+func (ConcurrentStoreSuite) TestOperations(c *check.C) {
+	mem := MemoryLocalStore()
+	store := NewConcurrentLocalStore(mem)
+
+	c.Assert(store, check.NotNil)
+	expected := map[string]json.RawMessage{
+		"file1.json": []byte{0xf1, 0xe1, 0xd1},
+		"file2.json": []byte{0xf2, 0xe2, 0xd2},
+		"file3.json": []byte{0xf3, 0xe3, 0xd3},
+	}
+
+	for k, v := range expected {
+		err := store.SetMeta(k, v)
+		c.Assert(err, check.IsNil)
+	}
+
+	md, err := store.GetMeta()
+	c.Assert(err, check.IsNil)
+	c.Assert(md, check.HasLen, 3)
+	c.Assert(md, check.DeepEquals, expected)
+
+	// Nuke items
+	count := 3
+	for k := range expected {
+		err = store.DeleteMeta(k)
+		count--
+		c.Assert(err, check.IsNil)
+		md, err := store.GetMeta()
+		c.Assert(err, check.IsNil)
+		c.Assert(md, check.HasLen, count)
+	}
+
+	md, err = store.GetMeta()
+	c.Assert(err, check.IsNil)
+	c.Assert(md, check.HasLen, 0)
+
+	err = store.Close()
+	c.Assert(err, check.IsNil)
+}
diff --git a/client/filejsonstore/filejsonstore.go b/client/filejsonstore/filejsonstore.go
index fb9493e7..06a73abd 100644
--- a/client/filejsonstore/filejsonstore.go
+++ b/client/filejsonstore/filejsonstore.go
@@ -24,7 +24,9 @@ type FileJSONStore struct {
 // NewFileJSONStore returns a new metadata cache, implemented using raw JSON
 // files, stored in a directory provided by the client.
 // If the provided directory does not exist on disk, it will be created.
-// The provided metadata cache is not safe for concurrent access.
+// The provided metadata cache is not safe for concurrent access, if
+// concurrent access safety is requires, wrap local store in a
+// ConcurrentLocalStore.
 func NewFileJSONStore(baseDir string) (*FileJSONStore, error) {
 	return newImpl(baseDir, true)
 }
diff --git a/client/filejsonstore/filejsonstore_test.go b/client/filejsonstore/filejsonstore_test.go
index 7a6a139c..a6d7cfca 100644
--- a/client/filejsonstore/filejsonstore_test.go
+++ b/client/filejsonstore/filejsonstore_test.go
@@ -77,7 +77,8 @@ func (RawJSONStoreSuite) TestMetadataOperations(c *check.C) {
 	}
 
 	for k, v := range expected {
-		s.SetMeta(k, v)
+		err := s.SetMeta(k, v)
+		c.Assert(err, check.IsNil)
 	}
 
 	md, err := s.GetMeta()

From 3a1cce046117f23e34740f0d832bb895981ce681 Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Wed, 3 Aug 2022 13:43:12 +0200
Subject: [PATCH 26/43] Update client/filejsonstore/filejsonstore_test.go

Fixed spelling error found during review.

Co-authored-by: Joshua Lock <jlock@vmware.com>
Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 client/filejsonstore/filejsonstore_test.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/client/filejsonstore/filejsonstore_test.go b/client/filejsonstore/filejsonstore_test.go
index a6d7cfca..778f4808 100644
--- a/client/filejsonstore/filejsonstore_test.go
+++ b/client/filejsonstore/filejsonstore_test.go
@@ -15,7 +15,7 @@ type RawJSONStoreSuite struct{}
 
 var _ = check.Suite(&RawJSONStoreSuite{})
 
-// Hook up gocheck into the "go test" runnder
+// Hook up gocheck into the "go test" runner
 func Test(t *testing.T) { check.TestingT(t) }
 
 func (RawJSONStoreSuite) TestNewOk(c *check.C) {

From a42ffd546adf8c38a4d949112c3eda3282fd1429 Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Thu, 4 Aug 2022 08:44:57 +0200
Subject: [PATCH 27/43] Added tests to make sure returned struct implements
 LocalStore interface.

Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 client/concurrentlocalstore_test.go        |  4 +++-
 client/filejsonstore/filejsonstore_test.go | 13 +++++++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/client/concurrentlocalstore_test.go b/client/concurrentlocalstore_test.go
index 4c883f23..c4824f5d 100644
--- a/client/concurrentlocalstore_test.go
+++ b/client/concurrentlocalstore_test.go
@@ -15,8 +15,10 @@ var _ = check.Suite(&ConcurrentStoreSuite{})
 func ConcurrentTest(t *testing.T) { check.TestingT(t) }
 
 func (ConcurrentStoreSuite) TestOperations(c *check.C) {
+	var store LocalStore
+
 	mem := MemoryLocalStore()
-	store := NewConcurrentLocalStore(mem)
+	store = NewConcurrentLocalStore(mem)
 
 	c.Assert(store, check.NotNil)
 	expected := map[string]json.RawMessage{
diff --git a/client/filejsonstore/filejsonstore_test.go b/client/filejsonstore/filejsonstore_test.go
index 778f4808..e256f50d 100644
--- a/client/filejsonstore/filejsonstore_test.go
+++ b/client/filejsonstore/filejsonstore_test.go
@@ -9,6 +9,8 @@ import (
 	"testing"
 
 	"gopkg.in/check.v1"
+
+	"github.com/theupdateframework/go-tuf/client"
 )
 
 type RawJSONStoreSuite struct{}
@@ -160,3 +162,14 @@ func (RawJSONStoreSuite) TestDelete(c *check.C) {
 	err = s.DeleteMeta("non_existing.json")
 	c.Assert(errors.Is(err, os.ErrNotExist), check.Equals, true)
 }
+
+func (RawJSONStoreSuite) TestInterface(c *check.C) {
+	var localStore client.LocalStore
+	var err error
+
+	tmp := c.MkDir()
+	p := filepath.Join(tmp, "tuf_raw.db")
+	localStore, err = NewFileJSONStore(p)
+	c.Assert(localStore, check.NotNil)
+	c.Assert(err, check.IsNil)
+}

From 0e6634c474e43659677db53edeffcdb6b5a6fcff Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Tue, 9 Aug 2022 17:54:30 +0200
Subject: [PATCH 28/43] Update client/filejsonstore/filejsonstore.go

Co-authored-by: Ethan Lowman <53835328+ethan-lowman-dd@users.noreply.github.com>
Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 client/filejsonstore/filejsonstore.go | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/client/filejsonstore/filejsonstore.go b/client/filejsonstore/filejsonstore.go
index 06a73abd..3272b04e 100644
--- a/client/filejsonstore/filejsonstore.go
+++ b/client/filejsonstore/filejsonstore.go
@@ -10,8 +10,8 @@ import (
 	"github.com/theupdateframework/go-tuf/util"
 )
 
-// ErrNotJSON is returned when a metadata operation is attempted to be
-// performed against a file that does not seem to be a JSON file
+// ErrNotJSON is returned when a metadata operation is attempted
+// against a file that does not seem to be a JSON file
 // (e.g. does not end in .json, case sensitive).
 var ErrNotJSON = errors.New("file is not in JSON format")
 

From 9c5b0241101c067592bf2cf505deb89d822ee262 Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Tue, 9 Aug 2022 17:54:55 +0200
Subject: [PATCH 29/43] Update client/filejsonstore/filejsonstore_test.go

Co-authored-by: Ethan Lowman <53835328+ethan-lowman-dd@users.noreply.github.com>
Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 client/filejsonstore/filejsonstore_test.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/client/filejsonstore/filejsonstore_test.go b/client/filejsonstore/filejsonstore_test.go
index e256f50d..130767bc 100644
--- a/client/filejsonstore/filejsonstore_test.go
+++ b/client/filejsonstore/filejsonstore_test.go
@@ -88,7 +88,7 @@ func (RawJSONStoreSuite) TestMetadataOperations(c *check.C) {
 	c.Assert(md, check.HasLen, 3)
 	c.Assert(md, check.DeepEquals, expected)
 
-	// Nuke items
+	// Delete all items
 	count := 3
 	for k := range expected {
 		err = s.DeleteMeta(k)

From 0257d6deb559e3a36415e83bd696ebe6077a6154 Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Wed, 10 Aug 2022 08:13:14 +0200
Subject: [PATCH 30/43] Update client/filejsonstore/filejsonstore.go

Co-authored-by: Ethan Lowman <53835328+ethan-lowman-dd@users.noreply.github.com>
Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 client/filejsonstore/filejsonstore.go | 1 -
 1 file changed, 1 deletion(-)

diff --git a/client/filejsonstore/filejsonstore.go b/client/filejsonstore/filejsonstore.go
index 3272b04e..dd13651f 100644
--- a/client/filejsonstore/filejsonstore.go
+++ b/client/filejsonstore/filejsonstore.go
@@ -65,7 +65,6 @@ func newImpl(baseDir string, recurse bool) (*FileJSONStore, error) {
 // GetMeta returns the currently cached set of metadata files.
 func (f *FileJSONStore) GetMeta() (map[string]json.RawMessage, error) {
 	names, err := os.ReadDir(f.baseDir)
-
 	if err != nil {
 		return nil, err
 	}

From dafc16122c8fd3ebd6c290e681139229f007e8c0 Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Wed, 10 Aug 2022 08:13:59 +0200
Subject: [PATCH 31/43] Update client/filejsonstore/filejsonstore_test.go

Co-authored-by: Ethan Lowman <53835328+ethan-lowman-dd@users.noreply.github.com>
Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 client/filejsonstore/filejsonstore_test.go | 1 -
 1 file changed, 1 deletion(-)

diff --git a/client/filejsonstore/filejsonstore_test.go b/client/filejsonstore/filejsonstore_test.go
index 130767bc..8fb4ece6 100644
--- a/client/filejsonstore/filejsonstore_test.go
+++ b/client/filejsonstore/filejsonstore_test.go
@@ -136,7 +136,6 @@ func (RawJSONStoreSuite) TestNoJSON(c *check.C) {
 		err := s.SetMeta(f, []byte{})
 		c.Assert(err, check.Equals, ErrNotJSON)
 	}
-
 }
 
 func (RawJSONStoreSuite) TestClose(c *check.C) {

From 96769ffa88a49fd0b95de88f254486ca0befacb5 Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Wed, 10 Aug 2022 10:55:40 +0200
Subject: [PATCH 32/43] Made FileJSONStore safe for concurrent access. Moved
 IsMetaFile to new pkg, internal/fsutil Permission bits are validated when
 access the cache.

Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 client/filejsonstore/filejsonstore.go      | 82 +++++++++++++-------
 client/filejsonstore/filejsonstore_test.go | 88 +++++++++++++++++++---
 internal/fsutil/fsutil.go                  | 39 ++++++++++
 local_store.go                             |  5 +-
 util/util.go                               | 14 ----
 5 files changed, 174 insertions(+), 54 deletions(-)
 create mode 100644 internal/fsutil/fsutil.go

diff --git a/client/filejsonstore/filejsonstore.go b/client/filejsonstore/filejsonstore.go
index dd13651f..61442800 100644
--- a/client/filejsonstore/filejsonstore.go
+++ b/client/filejsonstore/filejsonstore.go
@@ -6,7 +6,9 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"sync"
 
+	"github.com/theupdateframework/go-tuf/internal/fsutil"
 	"github.com/theupdateframework/go-tuf/util"
 )
 
@@ -15,23 +17,33 @@ import (
 // (e.g. does not end in .json, case sensitive).
 var ErrNotJSON = errors.New("file is not in JSON format")
 
+// ErrToPermissive is returned when the metadata directory, or a metadata
+// file has too permissive file mode bits set
+var ErrTooPermissive = errors.New("permissions are too permissive")
+
+const (
+	// user:  rwx
+	// group: r-x
+	// other: ---
+	dirCreateMode = os.FileMode(0750)
+	// user:  rw-
+	// group: r--
+	// other: ---
+	fileCreateMode = os.FileMode(0640)
+)
+
 // FileJSONStore represents a local metadata cache relying on raw JSON files
 // as retrieved from the remote repository.
 type FileJSONStore struct {
+	mtx     sync.RWMutex
 	baseDir string
 }
 
 // NewFileJSONStore returns a new metadata cache, implemented using raw JSON
 // files, stored in a directory provided by the client.
 // If the provided directory does not exist on disk, it will be created.
-// The provided metadata cache is not safe for concurrent access, if
-// concurrent access safety is requires, wrap local store in a
-// ConcurrentLocalStore.
+// The provided metadata cache is afe for concurrent access
 func NewFileJSONStore(baseDir string) (*FileJSONStore, error) {
-	return newImpl(baseDir, true)
-}
-
-func newImpl(baseDir string, recurse bool) (*FileJSONStore, error) {
 	var f = FileJSONStore{
 		baseDir: baseDir,
 	}
@@ -41,22 +53,24 @@ func newImpl(baseDir string, recurse bool) (*FileJSONStore, error) {
 	fi, err := os.Stat(baseDir)
 	if err != nil {
 		pe, ok := err.(*os.PathError)
-		if ok && errors.Is(pe.Err, os.ErrNotExist) && recurse {
+		if ok && errors.Is(pe.Err, os.ErrNotExist) {
 			// Create the directory
-			// user:  rwx
-			// group: r-x
-			// other: ---
-			err = os.MkdirAll(baseDir, 0750)
-			if err == nil {
-				return newImpl(baseDir, false)
+			if err = os.MkdirAll(baseDir, dirCreateMode); err != nil {
+				return nil, err
 			}
+		} else {
+			return nil, err
+		}
+	} else {
+		// Verify that it is a directory
+		if !fi.IsDir() {
+			return nil, fmt.Errorf("can not open %s, not a directory",
+				baseDir)
+		}
+		// Verify file mode is not too permissive.
+		if err = fsutil.EnsurePermission(fi, dirCreateMode); err != nil {
+			return nil, ErrTooPermissive
 		}
-		return nil, err
-	}
-
-	if !fi.IsDir() {
-		return nil, fmt.Errorf("can not open %s, not a directory",
-			baseDir)
 	}
 
 	return &f, nil
@@ -64,6 +78,9 @@ func newImpl(baseDir string, recurse bool) (*FileJSONStore, error) {
 
 // GetMeta returns the currently cached set of metadata files.
 func (f *FileJSONStore) GetMeta() (map[string]json.RawMessage, error) {
+	f.mtx.RLock()
+	defer f.mtx.RUnlock()
+
 	names, err := os.ReadDir(f.baseDir)
 	if err != nil {
 		return nil, err
@@ -72,11 +89,21 @@ func (f *FileJSONStore) GetMeta() (map[string]json.RawMessage, error) {
 	meta := map[string]json.RawMessage{}
 	for _, name := range names {
 		p := filepath.FromSlash(filepath.Join(f.baseDir, name.Name()))
-		if ok, err := util.IsMetaFile(name); !ok {
+		ok, err := fsutil.IsMetaFile(name)
+		if err != nil {
+			return nil, err
+		}
+		if !ok {
 			continue
-		} else if err != nil {
+		}
+		// Verify permissions
+		info, err := name.Info()
+		if err != nil {
 			return nil, err
 		}
+		if err = fsutil.EnsurePermission(info, fileCreateMode); err != nil {
+			return nil, ErrTooPermissive
+		}
 		b, err := os.ReadFile(p)
 		if err != nil {
 			return nil, err
@@ -90,21 +117,24 @@ func (f *FileJSONStore) GetMeta() (map[string]json.RawMessage, error) {
 // SetMeta stores a metadata file in the cache. If the metadata file exist,
 // it will be overwritten.
 func (f *FileJSONStore) SetMeta(name string, meta json.RawMessage) error {
+	f.mtx.Lock()
+	defer f.mtx.Unlock()
+
 	if filepath.Ext(name) != ".json" {
 		return ErrNotJSON
 	}
 
 	p := filepath.FromSlash(filepath.Join(f.baseDir, name))
-	// user:  rw-
-	// group: r--
-	// other: ---
-	err := util.AtomicallyWriteFile(p, meta, 0640)
+	err := util.AtomicallyWriteFile(p, meta, fileCreateMode)
 	return err
 }
 
 // DeleteMeta deletes a metadata file from the cache.
 // If the file does not exist, an *os.PathError is returned.
 func (f *FileJSONStore) DeleteMeta(name string) error {
+	f.mtx.Lock()
+	defer f.mtx.Unlock()
+
 	if filepath.Ext(name) != ".json" {
 		return ErrNotJSON
 	}
diff --git a/client/filejsonstore/filejsonstore_test.go b/client/filejsonstore/filejsonstore_test.go
index 8fb4ece6..dfc54a62 100644
--- a/client/filejsonstore/filejsonstore_test.go
+++ b/client/filejsonstore/filejsonstore_test.go
@@ -13,14 +13,14 @@ import (
 	"github.com/theupdateframework/go-tuf/client"
 )
 
-type RawJSONStoreSuite struct{}
+type FileJSONStoreSuite struct{}
 
-var _ = check.Suite(&RawJSONStoreSuite{})
+var _ = check.Suite(&FileJSONStoreSuite{})
 
 // Hook up gocheck into the "go test" runner
 func Test(t *testing.T) { check.TestingT(t) }
 
-func (RawJSONStoreSuite) TestNewOk(c *check.C) {
+func (FileJSONStoreSuite) TestNewOk(c *check.C) {
 	tmp := c.MkDir()
 	p := filepath.Join(tmp, "tuf_raw.db")
 
@@ -41,7 +41,7 @@ func (RawJSONStoreSuite) TestNewOk(c *check.C) {
 	c.Assert(fi.IsDir(), check.Equals, true)
 }
 
-func (RawJSONStoreSuite) TestNewFileExists(c *check.C) {
+func (FileJSONStoreSuite) TestNewFileExists(c *check.C) {
 	tmp := c.MkDir()
 	p := filepath.Join(tmp, "tuf_raw.db")
 
@@ -58,7 +58,37 @@ func (RawJSONStoreSuite) TestNewFileExists(c *check.C) {
 	c.Assert(found, check.Equals, true)
 }
 
-func (RawJSONStoreSuite) TestGetMetaEmpty(c *check.C) {
+func (FileJSONStoreSuite) TestNewDirectoryExists(c *check.C) {
+	tmp := c.MkDir()
+	p := filepath.Join(tmp, "tuf_raw.db")
+
+	err := os.Mkdir(p, 0750)
+	c.Assert(err, check.IsNil)
+
+	// Create implementation
+	s, err := NewFileJSONStore(p)
+	c.Assert(s, check.NotNil)
+	c.Assert(err, check.IsNil)
+
+	// Modify the directory permission and try again
+	err = os.Chmod(p, 0751)
+	s, err = NewFileJSONStore(p)
+	c.Assert(s, check.IsNil)
+	c.Assert(err, check.Equals, ErrTooPermissive)
+}
+
+func (FileJSONStoreSuite) TestNewNoCreate(c *check.C) {
+	tmp := c.MkDir()
+	p := filepath.Join(tmp, "tuf_raw.db")
+
+	// Clear the write bit for the user
+	err := os.Chmod(tmp, 0551)
+	s, err := NewFileJSONStore(p)
+	c.Assert(s, check.IsNil)
+	c.Assert(err, check.NotNil)
+}
+
+func (FileJSONStoreSuite) TestGetMetaEmpty(c *check.C) {
 	tmp := c.MkDir()
 	p := filepath.Join(tmp, "tuf_raw.db")
 	s, err := NewFileJSONStore(p)
@@ -68,7 +98,20 @@ func (RawJSONStoreSuite) TestGetMetaEmpty(c *check.C) {
 	c.Assert(md, check.HasLen, 0)
 }
 
-func (RawJSONStoreSuite) TestMetadataOperations(c *check.C) {
+func (FileJSONStoreSuite) TestGetNoDirectory(c *check.C) {
+	tmp := c.MkDir()
+	p := filepath.Join(tmp, "tuf_raw.db")
+	s, err := NewFileJSONStore(p)
+
+	err = os.Remove(p)
+	c.Assert(err, check.IsNil)
+
+	md, err := s.GetMeta()
+	c.Assert(md, check.IsNil)
+	c.Assert(err, check.NotNil)
+}
+
+func (FileJSONStoreSuite) TestMetadataOperations(c *check.C) {
 	tmp := c.MkDir()
 	p := filepath.Join(tmp, "tuf_raw.db")
 	s, err := NewFileJSONStore(p)
@@ -104,7 +147,7 @@ func (RawJSONStoreSuite) TestMetadataOperations(c *check.C) {
 	c.Assert(md, check.HasLen, 0)
 }
 
-func (RawJSONStoreSuite) TestGetNoJSON(c *check.C) {
+func (FileJSONStoreSuite) TestGetNoJSON(c *check.C) {
 	tmp := c.MkDir()
 	p := filepath.Join(tmp, "tuf_raw.db")
 	s, err := NewFileJSONStore(p)
@@ -113,14 +156,32 @@ func (RawJSONStoreSuite) TestGetNoJSON(c *check.C) {
 
 	// Create a file which does not end with '.json'
 	fp := filepath.FromSlash(filepath.Join(p, "meta.xml"))
-	os.WriteFile(fp, []byte{}, 0644)
+	err = os.WriteFile(fp, []byte{}, 0644)
+	c.Assert(err, check.IsNil)
 
 	md, err := s.GetMeta()
 	c.Assert(err, check.IsNil)
 	c.Assert(md, check.HasLen, 0)
 }
 
-func (RawJSONStoreSuite) TestNoJSON(c *check.C) {
+func (FileJSONStoreSuite) TestGetTooPermissive(c *check.C) {
+	tmp := c.MkDir()
+	p := filepath.Join(tmp, "tuf_raw.db")
+	s, err := NewFileJSONStore(p)
+	c.Assert(s, check.NotNil)
+	c.Assert(err, check.IsNil)
+
+	// Create a file which does not end with '.json'
+	fp := filepath.FromSlash(filepath.Join(p, "meta.json"))
+	err = os.WriteFile(fp, []byte{}, 0644)
+	c.Assert(err, check.IsNil)
+
+	md, err := s.GetMeta()
+	c.Assert(md, check.IsNil)
+	c.Assert(err, check.Equals, ErrTooPermissive)
+}
+
+func (FileJSONStoreSuite) TestNoJSON(c *check.C) {
 	tmp := c.MkDir()
 	p := filepath.Join(tmp, "tuf_raw.db")
 	s, err := NewFileJSONStore(p)
@@ -138,7 +199,7 @@ func (RawJSONStoreSuite) TestNoJSON(c *check.C) {
 	}
 }
 
-func (RawJSONStoreSuite) TestClose(c *check.C) {
+func (FileJSONStoreSuite) TestClose(c *check.C) {
 	tmp := c.MkDir()
 	p := filepath.Join(tmp, "tuf_raw.db")
 	s, err := NewFileJSONStore(p)
@@ -149,7 +210,7 @@ func (RawJSONStoreSuite) TestClose(c *check.C) {
 	c.Assert(err, check.IsNil)
 }
 
-func (RawJSONStoreSuite) TestDelete(c *check.C) {
+func (FileJSONStoreSuite) TestDelete(c *check.C) {
 	tmp := c.MkDir()
 	p := filepath.Join(tmp, "tuf_raw.db")
 	s, err := NewFileJSONStore(p)
@@ -162,7 +223,7 @@ func (RawJSONStoreSuite) TestDelete(c *check.C) {
 	c.Assert(errors.Is(err, os.ErrNotExist), check.Equals, true)
 }
 
-func (RawJSONStoreSuite) TestInterface(c *check.C) {
+func (FileJSONStoreSuite) TestInterface(c *check.C) {
 	var localStore client.LocalStore
 	var err error
 
@@ -172,3 +233,6 @@ func (RawJSONStoreSuite) TestInterface(c *check.C) {
 	c.Assert(localStore, check.NotNil)
 	c.Assert(err, check.IsNil)
 }
+
+// test 3 file exist and is too permissive
+// test 4 remote base dir after create
diff --git a/internal/fsutil/fsutil.go b/internal/fsutil/fsutil.go
new file mode 100644
index 00000000..98883952
--- /dev/null
+++ b/internal/fsutil/fsutil.go
@@ -0,0 +1,39 @@
+// Package fsutil defiens a set of internal utility functions used to
+// interact with the file system.
+package fsutil
+
+import (
+	"errors"
+	"io/fs"
+	"os"
+	"path/filepath"
+)
+
+var ErrPermission = errors.New("unexpected permission")
+
+// IsMetaFile tests wheter a DirEntry appears to be a metaddata file or not.
+func IsMetaFile(e os.DirEntry) (bool, error) {
+	if e.IsDir() || filepath.Ext(e.Name()) != ".json" {
+		return false, nil
+	}
+
+	info, err := e.Info()
+	if err != nil {
+		return false, err
+	}
+
+	return info.Mode().IsRegular(), nil
+}
+
+// EnsurePemissions tests the provided file info to make sure the
+// permission bits matches the provided.
+func EnsurePermission(fi os.FileInfo, perm os.FileMode) error {
+	// Clear all bits which are note related to the permission.
+	mode := fi.Mode() & fs.ModePerm
+	mask := ^perm
+	if (mode & mask) != 0 {
+		return ErrPermission
+	}
+
+	return nil
+}
diff --git a/local_store.go b/local_store.go
index 86aed2c9..1409f13f 100644
--- a/local_store.go
+++ b/local_store.go
@@ -14,6 +14,7 @@ import (
 
 	"github.com/theupdateframework/go-tuf/data"
 	"github.com/theupdateframework/go-tuf/encrypted"
+	"github.com/theupdateframework/go-tuf/internal/fsutil"
 	"github.com/theupdateframework/go-tuf/internal/sets"
 	"github.com/theupdateframework/go-tuf/pkg/keys"
 	"github.com/theupdateframework/go-tuf/util"
@@ -234,7 +235,7 @@ func (f *fileSystemStore) GetMeta() (map[string]json.RawMessage, error) {
 	}
 
 	for _, e := range committed {
-		imf, err := util.IsMetaFile(e)
+		imf, err := fsutil.IsMetaFile(e)
 		if err != nil {
 			return nil, err
 		}
@@ -251,7 +252,7 @@ func (f *fileSystemStore) GetMeta() (map[string]json.RawMessage, error) {
 	}
 
 	for _, e := range staged {
-		imf, err := util.IsMetaFile(e)
+		imf, err := fsutil.IsMetaFile(e)
 		if err != nil {
 			return nil, err
 		}
diff --git a/util/util.go b/util/util.go
index dfcb67f3..0878c823 100644
--- a/util/util.go
+++ b/util/util.go
@@ -331,17 +331,3 @@ func AtomicallyWriteFile(filename string, data []byte, perm os.FileMode) error {
 
 	return nil
 }
-
-// IsMetaFile tests wheter a DirEntry appears to be a metaddata file or not.
-func IsMetaFile(e os.DirEntry) (bool, error) {
-	if e.IsDir() || filepath.Ext(e.Name()) != ".json" {
-		return false, nil
-	}
-
-	info, err := e.Info()
-	if err != nil {
-		return false, err
-	}
-
-	return info.Mode().IsRegular(), nil
-}

From 86d4b3337d33d6cd4101bb066e3731d2276cb996 Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Thu, 11 Aug 2022 15:42:46 +0200
Subject: [PATCH 33/43] Spelling error.

Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 client/filejsonstore/filejsonstore.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/client/filejsonstore/filejsonstore.go b/client/filejsonstore/filejsonstore.go
index 61442800..90cfe24f 100644
--- a/client/filejsonstore/filejsonstore.go
+++ b/client/filejsonstore/filejsonstore.go
@@ -42,7 +42,7 @@ type FileJSONStore struct {
 // NewFileJSONStore returns a new metadata cache, implemented using raw JSON
 // files, stored in a directory provided by the client.
 // If the provided directory does not exist on disk, it will be created.
-// The provided metadata cache is afe for concurrent access
+// The provided metadata cache is safe for concurrent access.
 func NewFileJSONStore(baseDir string) (*FileJSONStore, error) {
 	var f = FileJSONStore{
 		baseDir: baseDir,

From c33254ed20f5053280b674a2c476c064aa51648a Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Fri, 12 Aug 2022 07:37:51 +0200
Subject: [PATCH 34/43] Updates based on PR comments. Removed a test for
 satisfying an interface, and replaced with a compile time check.

Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 client/filejsonstore/filejsonstore.go      |  3 +++
 client/filejsonstore/filejsonstore_test.go | 16 ----------------
 2 files changed, 3 insertions(+), 16 deletions(-)

diff --git a/client/filejsonstore/filejsonstore.go b/client/filejsonstore/filejsonstore.go
index 90cfe24f..c80d8ede 100644
--- a/client/filejsonstore/filejsonstore.go
+++ b/client/filejsonstore/filejsonstore.go
@@ -8,6 +8,7 @@ import (
 	"path/filepath"
 	"sync"
 
+	"github.com/theupdateframework/go-tuf/client"
 	"github.com/theupdateframework/go-tuf/internal/fsutil"
 	"github.com/theupdateframework/go-tuf/util"
 )
@@ -39,6 +40,8 @@ type FileJSONStore struct {
 	baseDir string
 }
 
+var _ client.LocalStore = (*FileJSONStore)(nil)
+
 // NewFileJSONStore returns a new metadata cache, implemented using raw JSON
 // files, stored in a directory provided by the client.
 // If the provided directory does not exist on disk, it will be created.
diff --git a/client/filejsonstore/filejsonstore_test.go b/client/filejsonstore/filejsonstore_test.go
index dfc54a62..1fdc4e8b 100644
--- a/client/filejsonstore/filejsonstore_test.go
+++ b/client/filejsonstore/filejsonstore_test.go
@@ -9,8 +9,6 @@ import (
 	"testing"
 
 	"gopkg.in/check.v1"
-
-	"github.com/theupdateframework/go-tuf/client"
 )
 
 type FileJSONStoreSuite struct{}
@@ -222,17 +220,3 @@ func (FileJSONStoreSuite) TestDelete(c *check.C) {
 	err = s.DeleteMeta("non_existing.json")
 	c.Assert(errors.Is(err, os.ErrNotExist), check.Equals, true)
 }
-
-func (FileJSONStoreSuite) TestInterface(c *check.C) {
-	var localStore client.LocalStore
-	var err error
-
-	tmp := c.MkDir()
-	p := filepath.Join(tmp, "tuf_raw.db")
-	localStore, err = NewFileJSONStore(p)
-	c.Assert(localStore, check.NotNil)
-	c.Assert(err, check.IsNil)
-}
-
-// test 3 file exist and is too permissive
-// test 4 remote base dir after create

From f95757cdb451ac3ece4fa23c2f1bd4e00c24951b Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Fri, 19 Aug 2022 08:25:55 +0200
Subject: [PATCH 35/43] Disabled filesystem permission checks for windows.
 Windows filesystem permission is a bit different from UNIX like systems, and
 there is no good API in go to manipulate it. Nor is having these checks a
 requirement by the TUF spec.

This commit relies on build tags to inject the correct filesystem permssion
check, the Windows version always return "satisfied".

Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 internal/fsutil/fsutil.go       | 14 --------------
 internal/fsutil/perm.go         | 22 ++++++++++++++++++++++
 internal/fsutil/perm_windows.go | 14 ++++++++++++++
 3 files changed, 36 insertions(+), 14 deletions(-)
 create mode 100644 internal/fsutil/perm.go
 create mode 100644 internal/fsutil/perm_windows.go

diff --git a/internal/fsutil/fsutil.go b/internal/fsutil/fsutil.go
index 98883952..d07c72a7 100644
--- a/internal/fsutil/fsutil.go
+++ b/internal/fsutil/fsutil.go
@@ -4,7 +4,6 @@ package fsutil
 
 import (
 	"errors"
-	"io/fs"
 	"os"
 	"path/filepath"
 )
@@ -24,16 +23,3 @@ func IsMetaFile(e os.DirEntry) (bool, error) {
 
 	return info.Mode().IsRegular(), nil
 }
-
-// EnsurePemissions tests the provided file info to make sure the
-// permission bits matches the provided.
-func EnsurePermission(fi os.FileInfo, perm os.FileMode) error {
-	// Clear all bits which are note related to the permission.
-	mode := fi.Mode() & fs.ModePerm
-	mask := ^perm
-	if (mode & mask) != 0 {
-		return ErrPermission
-	}
-
-	return nil
-}
diff --git a/internal/fsutil/perm.go b/internal/fsutil/perm.go
new file mode 100644
index 00000000..9b0cb2ea
--- /dev/null
+++ b/internal/fsutil/perm.go
@@ -0,0 +1,22 @@
+//go:build !windows
+// +build !windows
+
+package fsutil
+
+import (
+	"io/fs"
+	"os"
+)
+
+// EnsurePemissions tests the provided file info to make sure the
+// permission bits matches the provided.
+func EnsurePermission(fi os.FileInfo, perm os.FileMode) error {
+	// Clear all bits which are note related to the permission.
+	mode := fi.Mode() & fs.ModePerm
+	mask := ^perm
+	if (mode & mask) != 0 {
+		return ErrPermission
+	}
+
+	return nil
+}
diff --git a/internal/fsutil/perm_windows.go b/internal/fsutil/perm_windows.go
new file mode 100644
index 00000000..2f8ed61c
--- /dev/null
+++ b/internal/fsutil/perm_windows.go
@@ -0,0 +1,14 @@
+package fsutil
+
+import (
+	"os"
+)
+
+// EnsurePemissions tests the provided file info to make sure the
+// permission bits matches the provided.
+// On Windows system the permission bits are not really compatible with
+// UNIX-like permission bits.
+// Currently this method will always return nil.
+func EnsurePermission(fi os.FileInfo, perm os.FileMode) error {
+	return nil
+}

From 7301a8cb964a4dfcf22d9a96d02d7930abe3e0a9 Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Mon, 22 Aug 2022 10:54:16 +0200
Subject: [PATCH 36/43] Moved the tests that rely on permission bits to a new
 test file. The permission bits are not executed during windows builds.

Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 client/filejsonstore/filejsonstore_test.go | 34 --------------
 client/filejsonstore/perm_test.go          | 52 ++++++++++++++++++++++
 2 files changed, 52 insertions(+), 34 deletions(-)
 create mode 100644 client/filejsonstore/perm_test.go

diff --git a/client/filejsonstore/filejsonstore_test.go b/client/filejsonstore/filejsonstore_test.go
index 1fdc4e8b..73a7a731 100644
--- a/client/filejsonstore/filejsonstore_test.go
+++ b/client/filejsonstore/filejsonstore_test.go
@@ -67,23 +67,6 @@ func (FileJSONStoreSuite) TestNewDirectoryExists(c *check.C) {
 	s, err := NewFileJSONStore(p)
 	c.Assert(s, check.NotNil)
 	c.Assert(err, check.IsNil)
-
-	// Modify the directory permission and try again
-	err = os.Chmod(p, 0751)
-	s, err = NewFileJSONStore(p)
-	c.Assert(s, check.IsNil)
-	c.Assert(err, check.Equals, ErrTooPermissive)
-}
-
-func (FileJSONStoreSuite) TestNewNoCreate(c *check.C) {
-	tmp := c.MkDir()
-	p := filepath.Join(tmp, "tuf_raw.db")
-
-	// Clear the write bit for the user
-	err := os.Chmod(tmp, 0551)
-	s, err := NewFileJSONStore(p)
-	c.Assert(s, check.IsNil)
-	c.Assert(err, check.NotNil)
 }
 
 func (FileJSONStoreSuite) TestGetMetaEmpty(c *check.C) {
@@ -162,23 +145,6 @@ func (FileJSONStoreSuite) TestGetNoJSON(c *check.C) {
 	c.Assert(md, check.HasLen, 0)
 }
 
-func (FileJSONStoreSuite) TestGetTooPermissive(c *check.C) {
-	tmp := c.MkDir()
-	p := filepath.Join(tmp, "tuf_raw.db")
-	s, err := NewFileJSONStore(p)
-	c.Assert(s, check.NotNil)
-	c.Assert(err, check.IsNil)
-
-	// Create a file which does not end with '.json'
-	fp := filepath.FromSlash(filepath.Join(p, "meta.json"))
-	err = os.WriteFile(fp, []byte{}, 0644)
-	c.Assert(err, check.IsNil)
-
-	md, err := s.GetMeta()
-	c.Assert(md, check.IsNil)
-	c.Assert(err, check.Equals, ErrTooPermissive)
-}
-
 func (FileJSONStoreSuite) TestNoJSON(c *check.C) {
 	tmp := c.MkDir()
 	p := filepath.Join(tmp, "tuf_raw.db")
diff --git a/client/filejsonstore/perm_test.go b/client/filejsonstore/perm_test.go
new file mode 100644
index 00000000..70be3b46
--- /dev/null
+++ b/client/filejsonstore/perm_test.go
@@ -0,0 +1,52 @@
+//go:build !windows
+// +build !windows
+
+package client
+
+import (
+	"os"
+	"path/filepath"
+
+	"gopkg.in/check.v1"
+)
+
+func (FileJSONStoreSuite) TestNewDirectoryExistsWrongPerm(c *check.C) {
+	tmp := c.MkDir()
+	p := filepath.Join(tmp, "tuf_raw.db")
+
+	err := os.Mkdir(p, 0750)
+	c.Assert(err, check.IsNil)
+
+	// Modify the directory permission and try again
+	err = os.Chmod(p, 0751)
+	s, err := NewFileJSONStore(p)
+	c.Assert(s, check.IsNil)
+	c.Assert(err, check.Equals, ErrTooPermissive)
+}
+
+func (FileJSONStoreSuite) TestNewNoCreate(c *check.C) {
+	tmp := c.MkDir()
+	p := filepath.Join(tmp, "tuf_raw.db")
+
+	// Clear the write bit for the user
+	err := os.Chmod(tmp, 0551)
+	s, err := NewFileJSONStore(p)
+	c.Assert(s, check.IsNil)
+	c.Assert(err, check.NotNil)
+}
+
+func (FileJSONStoreSuite) TestGetTooPermissive(c *check.C) {
+	tmp := c.MkDir()
+	p := filepath.Join(tmp, "tuf_raw.db")
+	s, err := NewFileJSONStore(p)
+	c.Assert(s, check.NotNil)
+	c.Assert(err, check.IsNil)
+
+	fp := filepath.FromSlash(filepath.Join(p, "meta.json"))
+	err = os.WriteFile(fp, []byte{}, 0644)
+	c.Assert(err, check.IsNil)
+
+	md, err := s.GetMeta()
+	c.Assert(md, check.IsNil)
+	c.Assert(err, check.Equals, ErrTooPermissive)
+}

From 39f4018e9f28e0822df1a4026ff3d0316175d04b Mon Sep 17 00:00:00 2001
From: Ethan Lowman <ethan.lowman@datadoghq.com>
Date: Tue, 23 Aug 2022 17:39:00 -0400
Subject: [PATCH 37/43] Clarify permissions check naming and comment, add tests

Signed-off-by: Ethan Lowman <ethan.lowman@datadoghq.com>
---
 client/filejsonstore/filejsonstore.go |  4 +-
 internal/fsutil/fsutil.go             |  3 --
 internal/fsutil/perm.go               | 26 ++++++----
 internal/fsutil/perm_test.go          | 71 +++++++++++++++++++++++++++
 internal/fsutil/perm_windows.go       |  4 +-
 5 files changed, 92 insertions(+), 16 deletions(-)
 create mode 100644 internal/fsutil/perm_test.go

diff --git a/client/filejsonstore/filejsonstore.go b/client/filejsonstore/filejsonstore.go
index c80d8ede..b4375437 100644
--- a/client/filejsonstore/filejsonstore.go
+++ b/client/filejsonstore/filejsonstore.go
@@ -71,7 +71,7 @@ func NewFileJSONStore(baseDir string) (*FileJSONStore, error) {
 				baseDir)
 		}
 		// Verify file mode is not too permissive.
-		if err = fsutil.EnsurePermission(fi, dirCreateMode); err != nil {
+		if err = fsutil.EnsureMaxPermissions(fi, dirCreateMode); err != nil {
 			return nil, ErrTooPermissive
 		}
 	}
@@ -104,7 +104,7 @@ func (f *FileJSONStore) GetMeta() (map[string]json.RawMessage, error) {
 		if err != nil {
 			return nil, err
 		}
-		if err = fsutil.EnsurePermission(info, fileCreateMode); err != nil {
+		if err = fsutil.EnsureMaxPermissions(info, fileCreateMode); err != nil {
 			return nil, ErrTooPermissive
 		}
 		b, err := os.ReadFile(p)
diff --git a/internal/fsutil/fsutil.go b/internal/fsutil/fsutil.go
index d07c72a7..774246f8 100644
--- a/internal/fsutil/fsutil.go
+++ b/internal/fsutil/fsutil.go
@@ -3,13 +3,10 @@
 package fsutil
 
 import (
-	"errors"
 	"os"
 	"path/filepath"
 )
 
-var ErrPermission = errors.New("unexpected permission")
-
 // IsMetaFile tests wheter a DirEntry appears to be a metaddata file or not.
 func IsMetaFile(e os.DirEntry) (bool, error) {
 	if e.IsDir() || filepath.Ext(e.Name()) != ".json" {
diff --git a/internal/fsutil/perm.go b/internal/fsutil/perm.go
index 9b0cb2ea..f94add60 100644
--- a/internal/fsutil/perm.go
+++ b/internal/fsutil/perm.go
@@ -4,18 +4,26 @@
 package fsutil
 
 import (
-	"io/fs"
+	"fmt"
 	"os"
 )
 
-// EnsurePemissions tests the provided file info to make sure the
-// permission bits matches the provided.
-func EnsurePermission(fi os.FileInfo, perm os.FileMode) error {
-	// Clear all bits which are note related to the permission.
-	mode := fi.Mode() & fs.ModePerm
-	mask := ^perm
-	if (mode & mask) != 0 {
-		return ErrPermission
+// EnsureMaxPermissions tests the provided file info, returning an error if the
+// file's permission bits contain excess permissions not set in maxPerms.
+//
+// For example, a file with permissions -rw------- will successfully validate
+// with maxPerms -rw-r--r-- or -rw-rw-r--, but will not validate with maxPerms
+// -r-------- (due to excess --w------- permission) or --w------- (due to
+// excess -r-------- permission).
+//
+// Only permission bits of the file modes are considered.
+func EnsureMaxPermissions(fi os.FileInfo, maxPerms os.FileMode) error {
+	gotPerm := fi.Mode().Perm()
+	forbiddenPerms := (^maxPerms).Perm()
+	excessPerms := gotPerm & forbiddenPerms
+
+	if excessPerms != 0 {
+		return fmt.Errorf("permission bits for file %v failed validation: want at most %v, got %v with excess perms %v", fi.Name(), maxPerms.Perm(), gotPerm, excessPerms)
 	}
 
 	return nil
diff --git a/internal/fsutil/perm_test.go b/internal/fsutil/perm_test.go
new file mode 100644
index 00000000..6061d291
--- /dev/null
+++ b/internal/fsutil/perm_test.go
@@ -0,0 +1,71 @@
+//go:build !windows
+// +build !windows
+
+package fsutil
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestEnsureMaxPermissions(t *testing.T) {
+	tmp := t.TempDir()
+	p := filepath.Join(tmp, "file.txt")
+
+	// Start with 0644 and change using os.Chmod so umask doesn't interfere.
+	err := os.WriteFile(p, []byte(`AAA`), 0644)
+	assert.NoError(t, err)
+
+	// Check matching (1)
+	err = os.Chmod(p, 0464)
+	assert.NoError(t, err)
+	fi, err := os.Stat(p)
+	assert.NoError(t, err)
+	err = EnsureMaxPermissions(fi, os.FileMode(0464))
+	assert.NoError(t, err)
+
+	// Check matching (2)
+	err = os.Chmod(p, 0642)
+	assert.NoError(t, err)
+	fi, err = os.Stat(p)
+	assert.NoError(t, err)
+	err = EnsureMaxPermissions(fi, os.FileMode(0642))
+	assert.NoError(t, err)
+
+	// Check matching with file mode bits
+	err = os.Chmod(p, 0444)
+	assert.NoError(t, err)
+	fi, err = os.Stat(p)
+	assert.NoError(t, err)
+	err = EnsureMaxPermissions(fi, os.ModeSymlink|os.ModeAppend|os.FileMode(0444))
+	assert.NoError(t, err)
+
+	// Check not matching (1)
+	err = os.Chmod(p, 0444)
+	assert.NoError(t, err)
+	fi, err = os.Stat(p)
+	assert.NoError(t, err)
+	err = EnsureMaxPermissions(fi, os.FileMode(0400))
+	assert.Error(t, err)
+
+	// Check not matching (2)
+	err = os.Chmod(p, 0444)
+	assert.NoError(t, err)
+	fi, err = os.Stat(p)
+	assert.NoError(t, err)
+	err = EnsureMaxPermissions(fi, os.FileMode(0222))
+	assert.Error(t, err)
+	fmt.Println(err)
+
+	// Check matching due to more restrictive perms on file
+	err = os.Chmod(p, 0444)
+	assert.NoError(t, err)
+	fi, err = os.Stat(p)
+	assert.NoError(t, err)
+	err = EnsureMaxPermissions(fi, os.FileMode(0666))
+	assert.NoError(t, err)
+}
diff --git a/internal/fsutil/perm_windows.go b/internal/fsutil/perm_windows.go
index 2f8ed61c..11b0d0c7 100644
--- a/internal/fsutil/perm_windows.go
+++ b/internal/fsutil/perm_windows.go
@@ -4,11 +4,11 @@ import (
 	"os"
 )
 
-// EnsurePemissions tests the provided file info to make sure the
+// EnsureMaxPermissions tests the provided file info to make sure the
 // permission bits matches the provided.
 // On Windows system the permission bits are not really compatible with
 // UNIX-like permission bits.
 // Currently this method will always return nil.
-func EnsurePermission(fi os.FileInfo, perm os.FileMode) error {
+func EnsureMaxPermissions(fi os.FileInfo, perm os.FileMode) error {
 	return nil
 }

From 01bbd76469b9719e169b222d825777ebd27dd722 Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Wed, 24 Aug 2022 07:40:57 +0200
Subject: [PATCH 38/43] Update internal/fsutil/fsutil.go

Co-authored-by: Ethan Lowman <53835328+ethan-lowman-dd@users.noreply.github.com>
Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 internal/fsutil/fsutil.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/internal/fsutil/fsutil.go b/internal/fsutil/fsutil.go
index 774246f8..a169609d 100644
--- a/internal/fsutil/fsutil.go
+++ b/internal/fsutil/fsutil.go
@@ -7,7 +7,7 @@ import (
 	"path/filepath"
 )
 
-// IsMetaFile tests wheter a DirEntry appears to be a metaddata file or not.
+// IsMetaFile tests wheter a DirEntry appears to be a metadata file or not.
 func IsMetaFile(e os.DirEntry) (bool, error) {
 	if e.IsDir() || filepath.Ext(e.Name()) != ".json" {
 		return false, nil

From 19ef1ace68213f03c278ee98e2e3668f47d22cd2 Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Wed, 24 Aug 2022 08:28:25 +0200
Subject: [PATCH 39/43] Updates based on feeback. Mostly minor things like
 removing sentinel errors, wrapping errors from std library.

Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 client/concurrentlocalstore.go             | 49 -------------------
 client/concurrentlocalstore_test.go        | 57 ----------------------
 client/filejsonstore/filejsonstore.go      | 43 +++++++---------
 client/filejsonstore/filejsonstore_test.go |  5 +-
 client/filejsonstore/perm_test.go          |  6 +--
 internal/fsutil/fsutil.go                  |  3 +-
 internal/fsutil/perm_windows.go            |  5 +-
 7 files changed, 30 insertions(+), 138 deletions(-)
 delete mode 100644 client/concurrentlocalstore.go
 delete mode 100644 client/concurrentlocalstore_test.go

diff --git a/client/concurrentlocalstore.go b/client/concurrentlocalstore.go
deleted file mode 100644
index f37f7aa1..00000000
--- a/client/concurrentlocalstore.go
+++ /dev/null
@@ -1,49 +0,0 @@
-package client
-
-import (
-	"encoding/json"
-	"sync"
-)
-
-// ConcurrentLocalStore provides a LocalStore over an existing LocalStore
-// implementation that is safe for concurrent access.
-type ConcurrentLocalStore struct {
-	mtx   sync.RWMutex
-	store LocalStore
-}
-
-// NewConcurrentLocalStore returns a wrapped LocalStore that is safe for
-// concurrent access.
-func NewConcurrentLocalStore(s LocalStore) *ConcurrentLocalStore {
-	return &ConcurrentLocalStore{
-		store: s,
-	}
-}
-
-// GetMeta returns all known targets.
-func (c *ConcurrentLocalStore) GetMeta() (map[string]json.RawMessage, error) {
-	c.mtx.RLock()
-	defer c.mtx.RUnlock()
-	return c.store.GetMeta()
-}
-
-// SetMeta updates the lcoal store with a new target.
-func (c *ConcurrentLocalStore) SetMeta(name string, meta json.RawMessage) error {
-	c.mtx.Lock()
-	defer c.mtx.Unlock()
-	return c.store.SetMeta(name, meta)
-}
-
-// DeleteMeta remves a target from the cache.
-func (c *ConcurrentLocalStore) DeleteMeta(name string) error {
-	c.mtx.Lock()
-	defer c.mtx.Unlock()
-	return c.store.DeleteMeta(name)
-}
-
-// Close closes the local store.
-func (c *ConcurrentLocalStore) Close() error {
-	c.mtx.Lock()
-	defer c.mtx.Unlock()
-	return c.store.Close()
-}
diff --git a/client/concurrentlocalstore_test.go b/client/concurrentlocalstore_test.go
deleted file mode 100644
index c4824f5d..00000000
--- a/client/concurrentlocalstore_test.go
+++ /dev/null
@@ -1,57 +0,0 @@
-package client
-
-import (
-	"encoding/json"
-	"testing"
-
-	"gopkg.in/check.v1"
-)
-
-type ConcurrentStoreSuite struct{}
-
-var _ = check.Suite(&ConcurrentStoreSuite{})
-
-// Hook up gocheck into the "go test" runnder
-func ConcurrentTest(t *testing.T) { check.TestingT(t) }
-
-func (ConcurrentStoreSuite) TestOperations(c *check.C) {
-	var store LocalStore
-
-	mem := MemoryLocalStore()
-	store = NewConcurrentLocalStore(mem)
-
-	c.Assert(store, check.NotNil)
-	expected := map[string]json.RawMessage{
-		"file1.json": []byte{0xf1, 0xe1, 0xd1},
-		"file2.json": []byte{0xf2, 0xe2, 0xd2},
-		"file3.json": []byte{0xf3, 0xe3, 0xd3},
-	}
-
-	for k, v := range expected {
-		err := store.SetMeta(k, v)
-		c.Assert(err, check.IsNil)
-	}
-
-	md, err := store.GetMeta()
-	c.Assert(err, check.IsNil)
-	c.Assert(md, check.HasLen, 3)
-	c.Assert(md, check.DeepEquals, expected)
-
-	// Nuke items
-	count := 3
-	for k := range expected {
-		err = store.DeleteMeta(k)
-		count--
-		c.Assert(err, check.IsNil)
-		md, err := store.GetMeta()
-		c.Assert(err, check.IsNil)
-		c.Assert(md, check.HasLen, count)
-	}
-
-	md, err = store.GetMeta()
-	c.Assert(err, check.IsNil)
-	c.Assert(md, check.HasLen, 0)
-
-	err = store.Close()
-	c.Assert(err, check.IsNil)
-}
diff --git a/client/filejsonstore/filejsonstore.go b/client/filejsonstore/filejsonstore.go
index b4375437..fba83571 100644
--- a/client/filejsonstore/filejsonstore.go
+++ b/client/filejsonstore/filejsonstore.go
@@ -13,15 +13,6 @@ import (
 	"github.com/theupdateframework/go-tuf/util"
 )
 
-// ErrNotJSON is returned when a metadata operation is attempted
-// against a file that does not seem to be a JSON file
-// (e.g. does not end in .json, case sensitive).
-var ErrNotJSON = errors.New("file is not in JSON format")
-
-// ErrToPermissive is returned when the metadata directory, or a metadata
-// file has too permissive file mode bits set
-var ErrTooPermissive = errors.New("permissions are too permissive")
-
 const (
 	// user:  rwx
 	// group: r-x
@@ -47,22 +38,20 @@ var _ client.LocalStore = (*FileJSONStore)(nil)
 // If the provided directory does not exist on disk, it will be created.
 // The provided metadata cache is safe for concurrent access.
 func NewFileJSONStore(baseDir string) (*FileJSONStore, error) {
-	var f = FileJSONStore{
+	f := &FileJSONStore{
 		baseDir: baseDir,
 	}
-	var err error
 
 	// Does the directory exist?
 	fi, err := os.Stat(baseDir)
 	if err != nil {
-		pe, ok := err.(*os.PathError)
-		if ok && errors.Is(pe.Err, os.ErrNotExist) {
+		if errors.Is(err, os.ErrNotExist) {
 			// Create the directory
 			if err = os.MkdirAll(baseDir, dirCreateMode); err != nil {
-				return nil, err
+				return nil, fmt.Errorf("error creating directory for metadata cache: %w", err)
 			}
 		} else {
-			return nil, err
+			return nil, fmt.Errorf("error getting FileInfo for %s: %w", baseDir, err)
 		}
 	} else {
 		// Verify that it is a directory
@@ -72,11 +61,11 @@ func NewFileJSONStore(baseDir string) (*FileJSONStore, error) {
 		}
 		// Verify file mode is not too permissive.
 		if err = fsutil.EnsureMaxPermissions(fi, dirCreateMode); err != nil {
-			return nil, ErrTooPermissive
+			return nil, err
 		}
 	}
 
-	return &f, nil
+	return f, nil
 }
 
 // GetMeta returns the currently cached set of metadata files.
@@ -86,12 +75,11 @@ func (f *FileJSONStore) GetMeta() (map[string]json.RawMessage, error) {
 
 	names, err := os.ReadDir(f.baseDir)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("error reading directory %s: %w", f.baseDir, err)
 	}
 
 	meta := map[string]json.RawMessage{}
 	for _, name := range names {
-		p := filepath.FromSlash(filepath.Join(f.baseDir, name.Name()))
 		ok, err := fsutil.IsMetaFile(name)
 		if err != nil {
 			return nil, err
@@ -102,14 +90,15 @@ func (f *FileJSONStore) GetMeta() (map[string]json.RawMessage, error) {
 		// Verify permissions
 		info, err := name.Info()
 		if err != nil {
-			return nil, err
+			return nil, fmt.Errorf("error retrieving FileInfo for %s: %w", name.Name(), err)
 		}
 		if err = fsutil.EnsureMaxPermissions(info, fileCreateMode); err != nil {
-			return nil, ErrTooPermissive
+			return nil, err
 		}
+		p := filepath.Join(f.baseDir, name.Name())
 		b, err := os.ReadFile(p)
 		if err != nil {
-			return nil, err
+			return nil, fmt.Errorf("error reading file %s: %w", name.Name(), err)
 		}
 		meta[name.Name()] = b
 	}
@@ -124,7 +113,7 @@ func (f *FileJSONStore) SetMeta(name string, meta json.RawMessage) error {
 	defer f.mtx.Unlock()
 
 	if filepath.Ext(name) != ".json" {
-		return ErrNotJSON
+		return fmt.Errorf("file %s is not a JSON file", name)
 	}
 
 	p := filepath.FromSlash(filepath.Join(f.baseDir, name))
@@ -139,12 +128,16 @@ func (f *FileJSONStore) DeleteMeta(name string) error {
 	defer f.mtx.Unlock()
 
 	if filepath.Ext(name) != ".json" {
-		return ErrNotJSON
+		return fmt.Errorf("file %s is not a JSON file", name)
 	}
 
 	p := filepath.FromSlash(filepath.Join(f.baseDir, name))
 	err := os.Remove(p)
-	return err
+
+	if err == nil {
+		return nil
+	}
+	return fmt.Errorf("error deleting file %s: %w", name, err)
 }
 
 // Close closes the metadata cache. This is a no-op.
diff --git a/client/filejsonstore/filejsonstore_test.go b/client/filejsonstore/filejsonstore_test.go
index 73a7a731..d3382718 100644
--- a/client/filejsonstore/filejsonstore_test.go
+++ b/client/filejsonstore/filejsonstore_test.go
@@ -159,7 +159,8 @@ func (FileJSONStoreSuite) TestNoJSON(c *check.C) {
 	}
 	for _, f := range files {
 		err := s.SetMeta(f, []byte{})
-		c.Assert(err, check.Equals, ErrNotJSON)
+		c.Assert(err, check.ErrorMatches, "file.*is not a JSON file")
+
 	}
 }
 
@@ -182,7 +183,7 @@ func (FileJSONStoreSuite) TestDelete(c *check.C) {
 	c.Assert(err, check.IsNil)
 
 	err = s.DeleteMeta("not_json.yml")
-	c.Assert(err, check.Equals, ErrNotJSON)
+	c.Assert(err, check.ErrorMatches, "file not_json\\.yml is not a JSON file")
 	err = s.DeleteMeta("non_existing.json")
 	c.Assert(errors.Is(err, os.ErrNotExist), check.Equals, true)
 }
diff --git a/client/filejsonstore/perm_test.go b/client/filejsonstore/perm_test.go
index 70be3b46..85efb723 100644
--- a/client/filejsonstore/perm_test.go
+++ b/client/filejsonstore/perm_test.go
@@ -21,7 +21,7 @@ func (FileJSONStoreSuite) TestNewDirectoryExistsWrongPerm(c *check.C) {
 	err = os.Chmod(p, 0751)
 	s, err := NewFileJSONStore(p)
 	c.Assert(s, check.IsNil)
-	c.Assert(err, check.Equals, ErrTooPermissive)
+	c.Assert(err, check.ErrorMatches, "permission bits for file tuf_raw.db failed.*")
 }
 
 func (FileJSONStoreSuite) TestNewNoCreate(c *check.C) {
@@ -42,11 +42,11 @@ func (FileJSONStoreSuite) TestGetTooPermissive(c *check.C) {
 	c.Assert(s, check.NotNil)
 	c.Assert(err, check.IsNil)
 
-	fp := filepath.FromSlash(filepath.Join(p, "meta.json"))
+	fp := filepath.Join(p, "meta.json")
 	err = os.WriteFile(fp, []byte{}, 0644)
 	c.Assert(err, check.IsNil)
 
 	md, err := s.GetMeta()
 	c.Assert(md, check.IsNil)
-	c.Assert(err, check.Equals, ErrTooPermissive)
+	c.Assert(err, check.ErrorMatches, "permission bits for file meta.json failed.*")
 }
diff --git a/internal/fsutil/fsutil.go b/internal/fsutil/fsutil.go
index a169609d..138f2103 100644
--- a/internal/fsutil/fsutil.go
+++ b/internal/fsutil/fsutil.go
@@ -3,6 +3,7 @@
 package fsutil
 
 import (
+	"fmt"
 	"os"
 	"path/filepath"
 )
@@ -15,7 +16,7 @@ func IsMetaFile(e os.DirEntry) (bool, error) {
 
 	info, err := e.Info()
 	if err != nil {
-		return false, err
+		return false, fmt.Errorf("error retrieving FileInfo for %s: %w", e.Name(), err)
 	}
 
 	return info.Mode().IsRegular(), nil
diff --git a/internal/fsutil/perm_windows.go b/internal/fsutil/perm_windows.go
index 11b0d0c7..cecfee65 100644
--- a/internal/fsutil/perm_windows.go
+++ b/internal/fsutil/perm_windows.go
@@ -7,7 +7,10 @@ import (
 // EnsureMaxPermissions tests the provided file info to make sure the
 // permission bits matches the provided.
 // On Windows system the permission bits are not really compatible with
-// UNIX-like permission bits.
+// UNIX-like permission bits. By setting the UNIX-like permission bits
+// on a Windows system only read/write by all users can be achieved.
+// See this issue for tracking and more details:
+// https://github.com/theupdateframework/go-tuf/issues/360
 // Currently this method will always return nil.
 func EnsureMaxPermissions(fi os.FileInfo, perm os.FileMode) error {
 	return nil

From db6ad66e7938408e4206cb4a596a946338a78f7c Mon Sep 17 00:00:00 2001
From: Ethan Lowman <ethan.lowman@datadoghq.com>
Date: Wed, 24 Aug 2022 12:43:50 -0400
Subject: [PATCH 40/43] Use fs.ErrNotExist instead of os.ErrNotExist as
 recommended by Go docs

Signed-off-by: Ethan Lowman <ethan.lowman@datadoghq.com>
---
 client/filejsonstore/filejsonstore.go | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/client/filejsonstore/filejsonstore.go b/client/filejsonstore/filejsonstore.go
index fba83571..6f2c445c 100644
--- a/client/filejsonstore/filejsonstore.go
+++ b/client/filejsonstore/filejsonstore.go
@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"io/fs"
 	"os"
 	"path/filepath"
 	"sync"
@@ -45,7 +46,7 @@ func NewFileJSONStore(baseDir string) (*FileJSONStore, error) {
 	// Does the directory exist?
 	fi, err := os.Stat(baseDir)
 	if err != nil {
-		if errors.Is(err, os.ErrNotExist) {
+		if errors.Is(err, fs.ErrNotExist) {
 			// Create the directory
 			if err = os.MkdirAll(baseDir, dirCreateMode); err != nil {
 				return nil, fmt.Errorf("error creating directory for metadata cache: %w", err)
@@ -56,8 +57,7 @@ func NewFileJSONStore(baseDir string) (*FileJSONStore, error) {
 	} else {
 		// Verify that it is a directory
 		if !fi.IsDir() {
-			return nil, fmt.Errorf("can not open %s, not a directory",
-				baseDir)
+			return nil, fmt.Errorf("can not open %s, not a directory", baseDir)
 		}
 		// Verify file mode is not too permissive.
 		if err = fsutil.EnsureMaxPermissions(fi, dirCreateMode); err != nil {

From ff675c651614b1bb33347a986a7fd06941355a86 Mon Sep 17 00:00:00 2001
From: Ethan Lowman <ethan.lowman@datadoghq.com>
Date: Wed, 24 Aug 2022 12:45:48 -0400
Subject: [PATCH 41/43] Clean up remaining unnecessary usage of
 filepath.FromSlash

Signed-off-by: Ethan Lowman <ethan.lowman@datadoghq.com>
---
 client/filejsonstore/filejsonstore.go      | 4 ++--
 client/filejsonstore/filejsonstore_test.go | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/client/filejsonstore/filejsonstore.go b/client/filejsonstore/filejsonstore.go
index 6f2c445c..94950b10 100644
--- a/client/filejsonstore/filejsonstore.go
+++ b/client/filejsonstore/filejsonstore.go
@@ -116,7 +116,7 @@ func (f *FileJSONStore) SetMeta(name string, meta json.RawMessage) error {
 		return fmt.Errorf("file %s is not a JSON file", name)
 	}
 
-	p := filepath.FromSlash(filepath.Join(f.baseDir, name))
+	p := filepath.Join(f.baseDir, name)
 	err := util.AtomicallyWriteFile(p, meta, fileCreateMode)
 	return err
 }
@@ -131,7 +131,7 @@ func (f *FileJSONStore) DeleteMeta(name string) error {
 		return fmt.Errorf("file %s is not a JSON file", name)
 	}
 
-	p := filepath.FromSlash(filepath.Join(f.baseDir, name))
+	p := filepath.Join(f.baseDir, name)
 	err := os.Remove(p)
 
 	if err == nil {
diff --git a/client/filejsonstore/filejsonstore_test.go b/client/filejsonstore/filejsonstore_test.go
index d3382718..2b78b85c 100644
--- a/client/filejsonstore/filejsonstore_test.go
+++ b/client/filejsonstore/filejsonstore_test.go
@@ -136,7 +136,7 @@ func (FileJSONStoreSuite) TestGetNoJSON(c *check.C) {
 	c.Assert(err, check.IsNil)
 
 	// Create a file which does not end with '.json'
-	fp := filepath.FromSlash(filepath.Join(p, "meta.xml"))
+	fp := filepath.Join(p, "meta.xml")
 	err = os.WriteFile(fp, []byte{}, 0644)
 	c.Assert(err, check.IsNil)
 

From 9ca46f4ffa3022ae032c449e520f58e91dcb48cf Mon Sep 17 00:00:00 2001
From: Ethan Lowman <ethan.lowman@datadoghq.com>
Date: Wed, 24 Aug 2022 13:47:23 -0400
Subject: [PATCH 42/43] Add missing error checks in tests

Signed-off-by: Ethan Lowman <ethan.lowman@datadoghq.com>
---
 client/filejsonstore/filejsonstore.go      | 4 +++-
 client/filejsonstore/filejsonstore_test.go | 9 +++++++--
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/client/filejsonstore/filejsonstore.go b/client/filejsonstore/filejsonstore.go
index 94950b10..41277c88 100644
--- a/client/filejsonstore/filejsonstore.go
+++ b/client/filejsonstore/filejsonstore.go
@@ -87,6 +87,7 @@ func (f *FileJSONStore) GetMeta() (map[string]json.RawMessage, error) {
 		if !ok {
 			continue
 		}
+
 		// Verify permissions
 		info, err := name.Info()
 		if err != nil {
@@ -95,6 +96,7 @@ func (f *FileJSONStore) GetMeta() (map[string]json.RawMessage, error) {
 		if err = fsutil.EnsureMaxPermissions(info, fileCreateMode); err != nil {
 			return nil, err
 		}
+
 		p := filepath.Join(f.baseDir, name.Name())
 		b, err := os.ReadFile(p)
 		if err != nil {
@@ -133,10 +135,10 @@ func (f *FileJSONStore) DeleteMeta(name string) error {
 
 	p := filepath.Join(f.baseDir, name)
 	err := os.Remove(p)
-
 	if err == nil {
 		return nil
 	}
+
 	return fmt.Errorf("error deleting file %s: %w", name, err)
 }
 
diff --git a/client/filejsonstore/filejsonstore_test.go b/client/filejsonstore/filejsonstore_test.go
index 2b78b85c..6d00e046 100644
--- a/client/filejsonstore/filejsonstore_test.go
+++ b/client/filejsonstore/filejsonstore_test.go
@@ -73,6 +73,7 @@ func (FileJSONStoreSuite) TestGetMetaEmpty(c *check.C) {
 	tmp := c.MkDir()
 	p := filepath.Join(tmp, "tuf_raw.db")
 	s, err := NewFileJSONStore(p)
+	c.Assert(err, check.IsNil)
 
 	md, err := s.GetMeta()
 	c.Assert(err, check.IsNil)
@@ -83,6 +84,7 @@ func (FileJSONStoreSuite) TestGetNoDirectory(c *check.C) {
 	tmp := c.MkDir()
 	p := filepath.Join(tmp, "tuf_raw.db")
 	s, err := NewFileJSONStore(p)
+	c.Assert(err, check.IsNil)
 
 	err = os.Remove(p)
 	c.Assert(err, check.IsNil)
@@ -96,6 +98,8 @@ func (FileJSONStoreSuite) TestMetadataOperations(c *check.C) {
 	tmp := c.MkDir()
 	p := filepath.Join(tmp, "tuf_raw.db")
 	s, err := NewFileJSONStore(p)
+	c.Assert(err, check.IsNil)
+
 	expected := map[string]json.RawMessage{
 		"file1.json": []byte{0xf1, 0xe1, 0xd1},
 		"file2.json": []byte{0xf2, 0xe2, 0xd2},
@@ -116,10 +120,12 @@ func (FileJSONStoreSuite) TestMetadataOperations(c *check.C) {
 	count := 3
 	for k := range expected {
 		err = s.DeleteMeta(k)
-		count--
 		c.Assert(err, check.IsNil)
+
 		md, err := s.GetMeta()
 		c.Assert(err, check.IsNil)
+
+		count--
 		c.Assert(md, check.HasLen, count)
 	}
 
@@ -160,7 +166,6 @@ func (FileJSONStoreSuite) TestNoJSON(c *check.C) {
 	for _, f := range files {
 		err := s.SetMeta(f, []byte{})
 		c.Assert(err, check.ErrorMatches, "file.*is not a JSON file")
-
 	}
 }
 

From 210b417dde860182155655dceb6739bfa2fa7fcb Mon Sep 17 00:00:00 2001
From: Fredrik Skogman <kommendorkapten@github.com>
Date: Mon, 12 Sep 2022 19:37:44 +0200
Subject: [PATCH 43/43] Make sure to test that returned err is nil in the
 tests.

Signed-off-by: Fredrik Skogman <kommendorkapten@github.com>
---
 client/filejsonstore/perm_test.go | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/client/filejsonstore/perm_test.go b/client/filejsonstore/perm_test.go
index 85efb723..cda58c43 100644
--- a/client/filejsonstore/perm_test.go
+++ b/client/filejsonstore/perm_test.go
@@ -19,6 +19,7 @@ func (FileJSONStoreSuite) TestNewDirectoryExistsWrongPerm(c *check.C) {
 
 	// Modify the directory permission and try again
 	err = os.Chmod(p, 0751)
+	c.Assert(err, check.IsNil)
 	s, err := NewFileJSONStore(p)
 	c.Assert(s, check.IsNil)
 	c.Assert(err, check.ErrorMatches, "permission bits for file tuf_raw.db failed.*")
@@ -30,6 +31,7 @@ func (FileJSONStoreSuite) TestNewNoCreate(c *check.C) {
 
 	// Clear the write bit for the user
 	err := os.Chmod(tmp, 0551)
+	c.Assert(err, check.IsNil)
 	s, err := NewFileJSONStore(p)
 	c.Assert(s, check.IsNil)
 	c.Assert(err, check.NotNil)