cmd: replace uses of deprecated io/ioutil

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

cmd/cfssljson/cfssljson.go

@@ -7,21 +7,21 @@ import (
 	"encoding/json"
 	"flag"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"os"
 
 	"github.com/cloudflare/cfssl/cli/version"
 )
 
 func readFile(filespec string) ([]byte, error) {
 	if filespec == "-" {
-		return ioutil.ReadAll(os.Stdin)
+		return io.ReadAll(os.Stdin)
 	}
-	return ioutil.ReadFile(filespec)
+	return os.ReadFile(filespec)
 }
 
 func writeFile(filespec, contents string, perms os.FileMode) {
-	err := ioutil.WriteFile(filespec, []byte(contents), perms)
+	err := os.WriteFile(filespec, []byte(contents), perms)
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "%v\n", err)
 		os.Exit(1)
@@ -184,7 +184,7 @@ func main() {
 	}
 
 	if contents, ok := input["ocspResponse"]; ok {
-		//ocspResponse is base64 encoded
+		// ocspResponse is base64 encoded
 		resp, err := base64.StdEncoding.DecodeString(contents.(string))
 		if err != nil {
 			fmt.Fprintf(os.Stderr, "Failed to parse ocspResponse: %v\n", err)

cmd/mkbundle/mkbundle.go

@@ -2,14 +2,14 @@
 // All certificates in the input file paths are checked for revocation and bundled together.
 //
 // Usage:
+//
 //	mkbundle -f bundle_file -nw number_of_workers certificate_file_path ...
 package main
 
 import (
 	"crypto/x509"
 	"encoding/pem"
 	"flag"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"sync"
@@ -32,7 +32,7 @@ func worker(paths chan string, bundler chan *x509.Certificate, pool *sync.WaitGr
 
 		log.Infof("Loading %s", path)
 
-		fileData, err := ioutil.ReadFile(path)
+		fileData, err := os.ReadFile(path)
 		if err != nil {
 			log.Warningf("%v", err)
 			continue

cmd/multirootca/api.go

@@ -3,7 +3,7 @@ package main
 import (
 	"encoding/json"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"net/http/httputil"
 
@@ -82,7 +82,7 @@ func dispatchRequest(w http.ResponseWriter, req *http.Request) {
 	}
 
 	defer req.Body.Close()
-	body, err := ioutil.ReadAll(req.Body)
+	body, err := io.ReadAll(req.Body)
 	if err != nil {
 		fail(w, req, http.StatusInternalServerError, 1, err.Error(), "while reading request body")
 		return