Merge pull request #2 from evilhamsterman/testing

Add error checking on input string

main.go

@@ -1,8 +1,10 @@
 package main
 
 import (
+	"encoding/base32"
 	"fmt"
 	"os"
+	"strings"
 	"time"
 
 	"github.com/pquerna/otp/totp"
@@ -12,6 +14,13 @@ func main() {
 	// All we care about is the last argument which is the secret
 	a := os.Args
 	s := a[len(a)-1]
+	s = strings.ToUpper(s)
+
+	_, err := base32.StdEncoding.DecodeString(s)
+	if err != nil {
+		fmt.Println("You must specify a valid base32 string")
+		os.Exit(1)
+	}
 
 	// Generate and return the code
 	c, err := totp.GenerateCode(s, time.Now())