1 files changed, 71 insertions, 19 deletions

diff --git a/src/scrypt.go b/src/scrypt.go
index 511546f..6e212b4 100644
--- a/src/scrypt.go
+++ b/src/scrypt.go
@@ -3,12 +3,14 @@ package scrypt
 import (
 	"crypto/rand"
 	"encoding/hex"
+	"flag"
 	"fmt"
 	"io"
 	"os"
 	"slices"
 
 	gt "gotext"
+	g  "gobang"
 )
 
 
@@ -39,17 +41,29 @@ var (
 
 
 
-type HashInput struct{
+type HashInputT struct{
 	Password []byte
 	Salt     []byte
 }
 
-type CheckInput struct{
+type CheckInputT struct{
 	Password []byte
 	Salt     []byte
 	Hash     []byte
 }
 
+type argsT struct{
+	allArgs []string
+	input   HashInputT
+}
+
+type envT struct{
+	args argsT
+	in   io.Reader
+	out  io.Writer
+	err  io.Writer
+}
+
 
 
 // Package scrypt implements the scrypt key derivation function as defined in
@@ -108,7 +122,7 @@ func scrypt(
 	return out, nil
 }
 
-func Hash(input HashInput) ([]byte, error) {
+func Hash(input HashInputT) ([]byte, error) {
 	if len(input.Salt) < _SALT_MIN_LENGTH {
 		return nil, ErrSaltTooSmall
 	}
@@ -137,8 +151,8 @@ func Salt() ([]byte, error) {
 	return SaltFrom(rand.Reader)
 }
 
-func Check(input CheckInput) (bool, error) {
-	hashInput := HashInput{
+func Check(input CheckInputT) (bool, error) {
+	hashInput := HashInputT{
 		Password: input.Password,
 		Salt:     input.Salt,
 	}
@@ -151,29 +165,67 @@ func Check(input CheckInput) (bool, error) {
 	return slices.Equal(candidate, input.Hash), nil
 }
 
+func usage(argv0 string, w io.Writer) {
+	fmt.Fprintf(
+		w,
+		"Usage: %s PASSWORD SALT\n",
+		argv0,
+	)
+}
 
+func getopt(allArgs []string, w io.Writer) (argsT, int) {
+	argv0 := allArgs[0]
+	argv  := allArgs[1:]
+	fs := flag.NewFlagSet("", flag.ContinueOnError)
+	fs.Usage = func() {}
+	fs.SetOutput(w)
 
-func Main() {
-	if len(os.Args) != 3 {
-		fmt.Fprintf(os.Stderr, gt.Gettext("Usage: scrypt PASSWORD SALT\n"))
-		os.Exit(2)
+	if fs.Parse(argv) != nil {
+		usage(argv0, w)
+		return argsT{}, 2
+	}
+
+	subArgs := fs.Args()
+	if len(subArgs) != 2 {
+		usage(argv0, w)
+		return argsT{}, 2
 	}
 
-	password := []byte(os.Args[1])
-	salt     := []byte(os.Args[2])
-	input    := HashInput{
+	password := []byte(subArgs[0])
+	salt     := []byte(subArgs[1])
+	input := HashInputT{
 		Password: password,
 		Salt:     salt,
 	}
 
-	payload, err := Hash(input)
+	return argsT{
+		allArgs: allArgs,
+		input:   input,
+	}, 0
+}
+
+func run(env envT) int {
+	payload, err := Hash(env.args.input)
 	if err != nil {
-		if err == ErrSaltTooSmall {
-			fmt.Fprintln(os.Stderr, err)
-			os.Exit(2)
-		}
-		panic(err)
+		fmt.Fprintln(env.err, err)
+		return 1
 	}
 
-	fmt.Println(hex.EncodeToString(payload))
+	fmt.Fprintln(env.out, hex.EncodeToString(payload))
+	return 0
+}
+
+
+
+func Main() {
+	g.Init()
+	gt.Init(Name, LOCALEDIR)
+	args, rc := getopt(os.Args, os.Stderr)
+	g.ExitIf(rc)
+	os.Exit(run(envT{
+		args: args,
+		in:   os.Stdin,
+		out:  os.Stdout,
+		err:  os.Stderr,
+	}))
 }