From 4ef8f5b630540fcb4eedf8c8d382560bfc34f382 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=89rico=20Rolim?= <erico.erc@gmail.com>
Date: Mon, 11 Jan 2021 00:47:03 -0300
Subject: [PATCH] Use ReadOrCreateFile in ReadBundleDatabase.
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Add error checking around the function where appropriate.

Also fail early when creating a new bundle if it isn't possible to
access the bundle database.

Signed-off-by: Érico Rolim <erico.erc@gmail.com>
---
 bundles.go        | 18 +++++-------------
 cmd/sbctl/main.go | 16 ++++++++++++++--
 sbctl.go          | 10 ++++++++--
 3 files changed, 27 insertions(+), 17 deletions(-)

diff --git a/bundles.go b/bundles.go
index 48eeacf..75774f4 100644
--- a/bundles.go
+++ b/bundles.go
@@ -28,22 +28,14 @@ type Bundles map[string]*Bundle
 
 var BundleDBPath = filepath.Join(DatabasePath, "bundles.db")
 
-func ReadBundleDatabase(dbpath string) Bundles {
-	bundles := make(Bundles)
-	os.MkdirAll(DatabasePath, os.ModePerm)
-	if _, err := os.Stat(BundleDBPath); os.IsNotExist(err) {
-		file, err := os.Create(BundleDBPath)
-		if err != nil {
-			log.Fatal(err)
-		}
-		file.Close()
-	}
-	f, err := ioutil.ReadFile(dbpath)
+func ReadBundleDatabase(dbpath string) (Bundles, error) {
+	f, err := ReadOrCreateFile(dbpath)
 	if err != nil {
-		log.Fatal(err)
+		return nil, err
 	}
+	bundles := make(Bundles)
 	json.Unmarshal(f, &bundles)
-	return bundles
+	return bundles, nil
 }
 
 func WriteBundleDatabase(dbpath string, bundles Bundles) {
diff --git a/cmd/sbctl/main.go b/cmd/sbctl/main.go
index a916a5f..5a2a044 100755
--- a/cmd/sbctl/main.go
+++ b/cmd/sbctl/main.go
@@ -200,6 +200,16 @@ func bundleCmd() *cobra.Command {
 			if err != nil {
 				log.Fatal(err)
 			}
+			// Fail early if user wants to save bundle but doesn't have permissions
+			var bundles sbctl.Bundles
+			if save {
+				// "err" needs to have been declared before this, otherwise it's necessary
+				// to use ":=", which shadows the "bundles" variable
+				bundles, err = sbctl.ReadBundleDatabase(sbctl.BundleDBPath)
+				if err != nil {
+					log.Fatalln(err)
+				}
+			}
 			bundle.Output = output
 			bundle.IntelMicrocode = intelucode
 			bundle.AMDMicrocode = amducode
@@ -212,7 +222,6 @@ func bundleCmd() *cobra.Command {
 			bundle.ESP = espPath
 			sbctl.CreateBundle(*bundle)
 			if save {
-				bundles := sbctl.ReadBundleDatabase(sbctl.BundleDBPath)
 				bundles[bundle.Output] = bundle
 				sbctl.WriteBundleDatabase(sbctl.BundleDBPath, bundles)
 				sbctl.FormatBundle(bundle.Output, bundle)
@@ -266,7 +275,10 @@ func removeBundleCmd() *cobra.Command {
 			if len(args) < 1 {
 				log.Fatal("Need to specify file")
 			}
-			bundles := sbctl.ReadBundleDatabase(sbctl.BundleDBPath)
+			bundles, err := sbctl.ReadBundleDatabase(sbctl.BundleDBPath)
+			if err != nil {
+				log.Fatalln(err)
+			}
 
 			if _, ok := bundles[args[0]]; !ok {
 				log.Printf("Bundle %s doesn't exist in database!\n", args[0])
diff --git a/sbctl.go b/sbctl.go
index a7eecb1..3f102a3 100644
--- a/sbctl.go
+++ b/sbctl.go
@@ -260,7 +260,10 @@ func CreateBundle(bundle Bundle) error {
 
 func GenerateAllBundles(sign bool) error {
 	msg.Println("Generating EFI bundles....")
-	bundles := ReadBundleDatabase(BundleDBPath)
+	bundles, err := ReadBundleDatabase(BundleDBPath)
+	if err != nil {
+		return err
+	}
 	out_create := true
 	out_sign := true
 	for _, bundle := range bundles {
@@ -291,7 +294,10 @@ func GenerateAllBundles(sign bool) error {
 }
 
 func ListBundles() {
-	bundles := ReadBundleDatabase(BundleDBPath)
+	bundles, err := ReadBundleDatabase(BundleDBPath)
+	if err != nil {
+		log.Fatalln(err)
+	}
 	for key, bundle := range bundles {
 		FormatBundle(key, bundle)
 	}