all: comply with linter recommendations #3

For HTTP server that use TLS, set the minimum TLS version and
ReadHeaderTimeout to mitigate slowloris attack.

For HTTP client or server that parameterize the use of InsecureSkipVerify,
annotate the line with "nolint:gosec" to allow the code pass the check.

Library that still use sha1, in example in DKIM and TOTP, skip the
warnings by annotating the line with "nolint:gosec".

A pointer variable now allocated their address before assigning its
value.

Any error that returned now wrapped using "%w".
Also, replace error checking using [errors.Is] or [errors.As] instead of
using equal or not-equal operators.

In "lib/http", replace any usage of "math/rand" with "crypto/rand".

Any call of [math/big.Rat.SetString] now annotated with "nolint:gosec"
since its false positive, the issue has been fixed in Go >= 1.17.7.

Any switch case that does not cover the rest of the possible values now
handled by adding the cases or by replacing the "default" case with
the rest of values.

1 files changed, 38 insertions, 49 deletions

diff --git a/lib/git/git.go b/lib/git/git.go
index 0f73b2b7..151e077a 100644
--- a/lib/git/git.go
+++ b/lib/git/git.go
@@ -58,8 +58,7 @@ func CheckoutRevision(repoDir, remoteName, branch, revision string) error {
 
 	err := cmd.Run()
 	if err != nil {
-		err = fmt.Errorf("CheckoutRevision: %s", err)
-		return err
+		return fmt.Errorf(`CheckoutRevision: %w`, err)
 	}
 
 	cmd = exec.Command("git", "checkout")
@@ -71,8 +70,7 @@ func CheckoutRevision(repoDir, remoteName, branch, revision string) error {
 
 	err = cmd.Run()
 	if err != nil {
-		err = fmt.Errorf("CheckoutRevision: %s", err)
-		return err
+		return fmt.Errorf(`CheckoutRevision: %w`, err)
 	}
 
 	cmd = exec.Command("git", "reset")
@@ -84,10 +82,10 @@ func CheckoutRevision(repoDir, remoteName, branch, revision string) error {
 
 	err = cmd.Run()
 	if err != nil {
-		err = fmt.Errorf("CheckoutRevision: %s", err)
+		return fmt.Errorf(`CheckoutRevision: %w`, err)
 	}
 
-	return err
+	return nil
 }
 
 // Clone the repository into destination directory.
@@ -96,8 +94,7 @@ func CheckoutRevision(repoDir, remoteName, branch, revision string) error {
 func Clone(remoteURL, dest string) (err error) {
 	err = os.MkdirAll(dest, 0700)
 	if err != nil {
-		err = fmt.Errorf("Clone: %s", err)
-		return
+		return fmt.Errorf(`Clone: %w`, err)
 	}
 
 	cmd := exec.Command("git", "clone")
@@ -109,10 +106,9 @@ func Clone(remoteURL, dest string) (err error) {
 
 	err = cmd.Run()
 	if err != nil {
-		err = fmt.Errorf("Clone: %s", err)
+		return fmt.Errorf(`Clone: %w`, err)
 	}
-
-	return
+	return nil
 }
 
 // FetchAll will fetch the latest commits and tags from remote.
@@ -126,14 +122,13 @@ func FetchAll(repoDir string) (err error) {
 
 	err = cmd.Run()
 	if err != nil {
-		err = fmt.Errorf("FetchAll: %s", err)
+		return fmt.Errorf(`FetchAll: %w`, err)
 	}
-
-	return
+	return nil
 }
 
 // FetchTags will fetch all tags from remote.
-func FetchTags(repoDir string) error {
+func FetchTags(repoDir string) (err error) {
 	cmd := exec.Command("git", "fetch")
 	cmd.Args = append(cmd.Args, "--quiet")
 	cmd.Args = append(cmd.Args, "--tags", "--force")
@@ -141,12 +136,11 @@ func FetchTags(repoDir string) error {
 	cmd.Stdout = _stdout
 	cmd.Stderr = _stderr
 
-	err := cmd.Run()
+	err = cmd.Run()
 	if err != nil {
-		err = fmt.Errorf("FetchTags: %s", err)
+		return fmt.Errorf(`FetchTags: %w`, err)
 	}
-
-	return err
+	return nil
 }
 
 // GetRemoteURL return remote URL or error if repository is not git or url is
@@ -161,8 +155,7 @@ func GetRemoteURL(repoDir, remoteName string) (url string, err error) {
 
 	gitIni, err := ini.Open(gitConfig)
 	if err != nil {
-		err = fmt.Errorf("GetRemote: %s", err)
-		return
+		return ``, fmt.Errorf(`GetRemote: %w`, err)
 	}
 
 	url, ok := gitIni.Get("remote", remoteName, "url", "")
@@ -187,13 +180,12 @@ func GetTag(repoDir, revision string) (tag string, err error) {
 
 	btag, err := cmd.Output()
 	if err != nil {
-		err = fmt.Errorf("GetTag: %s", err)
-		return
+		return ``, fmt.Errorf(`GetTag: %w`, err)
 	}
 
 	tag = string(bytes.TrimSpace(btag))
 
-	return
+	return tag, nil
 }
 
 // LatestCommit get the latest commit hash in short format from "ref".
@@ -210,13 +202,12 @@ func LatestCommit(repoDir, ref string) (commit string, err error) {
 
 	bcommit, err := cmd.Output()
 	if err != nil {
-		err = fmt.Errorf("LatestCommit: %s", err)
-		return
+		return ``, fmt.Errorf(`LatestCommit: %w`, err)
 	}
 
 	commit = string(bytes.TrimSpace(bcommit))
 
-	return
+	return commit, nil
 }
 
 // LatestTag get latest tag.
@@ -228,7 +219,7 @@ func LatestTag(repoDir string) (tag string, err error) {
 
 	bout, err := cmd.Output()
 	if err != nil {
-		return "", fmt.Errorf("LatestTag: %s", err)
+		return ``, fmt.Errorf(`LatestTag: %w`, err)
 	}
 
 	out := string(bytes.TrimSpace(bout))
@@ -243,7 +234,7 @@ func LatestTag(repoDir string) (tag string, err error) {
 
 	bout, err = cmd.Output()
 	if err != nil {
-		return "", fmt.Errorf("LatestTag: %s", err)
+		return ``, fmt.Errorf(`LatestTag: %w`, err)
 	}
 
 	tag = string(bytes.TrimSpace(bout))
@@ -254,18 +245,19 @@ func LatestTag(repoDir string) (tag string, err error) {
 // LatestVersion will try to get latest tag from repository.
 // If it's fail get the latest commit hash.
 func LatestVersion(repoDir string) (version string, err error) {
+	var logp = `LatestVersion`
+
 	version, err = LatestTag(repoDir)
 	if err == nil && len(version) > 0 {
-		return
+		return version, nil
 	}
 
 	version, err = LatestCommit(repoDir, "")
-	if err == nil {
-		return
+	if err != nil {
+		return ``, fmt.Errorf(`%s: %w`, logp, err)
 	}
 
-	err = fmt.Errorf("GetVersion: %s", err)
-	return
+	return version, nil
 }
 
 // ListTags get all tags from repository.
@@ -282,8 +274,7 @@ func ListTags(repoDir string) (tags []string, err error) {
 
 	bout, err := cmd.Output()
 	if err != nil {
-		err = fmt.Errorf("ListTag: %s", err)
-		return nil, err
+		return nil, fmt.Errorf(`ListTag: %w`, err)
 	}
 
 	sep := []byte{'\n'}
@@ -300,7 +291,7 @@ func ListTags(repoDir string) (tags []string, err error) {
 }
 
 // LogRevisions get commits between two revisions.
-func LogRevisions(repoDir, prevRevision, nextRevision string) error {
+func LogRevisions(repoDir, prevRevision, nextRevision string) (err error) {
 	cmd := exec.Command("git")
 	cmd.Args = append(cmd.Args, "--no-pager", "log", "--oneline",
 		prevRevision+"..."+nextRevision)
@@ -308,17 +299,17 @@ func LogRevisions(repoDir, prevRevision, nextRevision string) error {
 	cmd.Stdout = _stdout
 	cmd.Stderr = _stderr
 
-	err := cmd.Run()
+	err = cmd.Run()
 	if err != nil {
-		err = fmt.Errorf("CompareRevisions: %s", err)
+		return fmt.Errorf(`CompareRevisions: %w`, err)
 	}
 
-	return err
+	return nil
 }
 
 // RemoteChange change current repository remote name (e.g. "origin") to new
 // remote name and URL.
-func RemoteChange(repoDir, oldName, newName, newURL string) error {
+func RemoteChange(repoDir, oldName, newName, newURL string) (err error) {
 	if len(repoDir) == 0 {
 		return nil
 	}
@@ -329,10 +320,9 @@ func RemoteChange(repoDir, oldName, newName, newURL string) error {
 	cmd.Stdout = _stdout
 	cmd.Stderr = _stderr
 
-	err := cmd.Run()
+	err = cmd.Run()
 	if err != nil {
-		err = fmt.Errorf("RemoteChange: %s", err)
-		return err
+		return fmt.Errorf(`RemoteChange: %w`, err)
 	}
 
 	cmd = exec.Command("git")
@@ -343,10 +333,10 @@ func RemoteChange(repoDir, oldName, newName, newURL string) error {
 
 	err = cmd.Run()
 	if err != nil {
-		err = fmt.Errorf("RemoteChange: %s", err)
+		return fmt.Errorf(`RemoteChange: %w`, err)
 	}
 
-	return err
+	return nil
 }
 
 // RemoteBranches return list of remote branches.
@@ -361,13 +351,12 @@ func RemoteBranches(repoDir string) ([]string, error) {
 
 	bout, err := cmd.Output()
 	if err != nil {
-		err = fmt.Errorf("RemoteBranches: %s", err)
-		return nil, err
+		return nil, fmt.Errorf(`RemoteBranches: %w`, err)
 	}
 
 	bbranches := bytes.Split(bout, []byte{'\n'})
 	if len(bbranches) == 0 {
-		return nil, err
+		return nil, nil
 	}
 
 	var branches []string