From 4bec62f23c40fb7699b990aa3590b9345d868fc6 Mon Sep 17 00:00:00 2001
From: Ted Unangst <tedu@tedunangst.com>
Date: Wed, 25 Nov 2020 21:50:51 -0500
Subject: [PATCH] little more error checking for new usernames

---
 util.go | 19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/util.go b/util.go
index 04a6880..9f3311a 100644
--- a/util.go
+++ b/util.go
@@ -44,6 +44,7 @@ import (
 	"net"
 	"os"
 	"os/signal"
+	"regexp"
 	"strings"
 
 	"golang.org/x/crypto/bcrypt"
@@ -107,12 +108,16 @@ func initdb() {
 	}
 	r := bufio.NewReader(os.Stdin)
 
-	err = createuser(db, r)
+	initblobdb()
+
+	prepareStatements(db)
+
+	err = createserveruser(db)
 	if err != nil {
 		log.Print(err)
 		return
 	}
-	err = createserveruser(db)
+	err = createuser(db, r)
 	if err != nil {
 		log.Print(err)
 		return
@@ -153,9 +158,6 @@ func initdb() {
 	setconfig("loginmsg", "<h2>login</h2>")
 	setconfig("debug", 0)
 
-	initblobdb()
-
-	prepareStatements(db)
 	db.Close()
 	fmt.Printf("done.\n")
 	os.Exit(0)
@@ -307,6 +309,13 @@ func createuser(db *sql.DB, r *bufio.Reader) error {
 	if len(name) < 1 {
 		return fmt.Errorf("that's way too short")
 	}
+	re_name := regexp.MustCompile("^[[:alnum:]]+$")
+	if !re_name.MatchString(name) {
+		return fmt.Errorf("alphanumeric only please")
+	}
+	if _, err := butwhatabout(name); err == nil {
+		return fmt.Errorf("user already exists")
+	}
 	pass, err := askpassword(r)
 	if err != nil {
 		return err