added basic data layer functions for users

data/users.sh

@@ -0,0 +1,37 @@
+#!/bin/bash
+
+createSalt() {
+	head -c 12 /dev/urandom | base64
+}
+
+hashPassword() {
+	password="$1"
+	salt="$2"
+	echo "$password$salt" | sha512sum | cut -d' ' -f1
+}
+
+createUser() {
+	username="$1"
+	password="$2"
+	salt="$(createSalt)"
+	password="$(hashPassword "$password" "$salt")"
+	echo "INSERT INTO users (username, password, salt) VALUES (
+		'$(escape "$username")',
+		'$(escape "$password")',
+		'$(escape "$salt")'
+	)" | execute
+}
+
+loginUser() {
+	username="$1"
+	password="$2"
+
+	result="$(echo "SELECT password, salt FROM users WHERE username='$(escape "$username")'" | query)"
+	hash="$(echo "$result" | getColumns 1)"
+	salt="$(echo "$result" | getColumns 2)"
+
+	password="$(hashPassword "$password" "$salt")"
+
+	test "$password" = "$hash"
+	return
+}