From a6c96f126ca333fb10750165161084c7c7dd0b34 Mon Sep 17 00:00:00 2001
From: Nicolas Martignoni <nicolas@martignoni.net>
Date: Mon, 19 Mar 2018 17:28:36 +0100
Subject: [PATCH] Implement SSID with UTF chars. Issue #38.

---
 bin/changewifisettings.sh | 12 +++++++-----
 index.php                 | 11 ++++++++---
 2 files changed, 15 insertions(+), 8 deletions(-)

diff --git a/bin/changewifisettings.sh b/bin/changewifisettings.sh
index ae90f1d..d69cb8a 100644
--- a/bin/changewifisettings.sh
+++ b/bin/changewifisettings.sh
@@ -49,13 +49,15 @@ sed -i "/^channel=/c\channel=$NEWCHANNEL" "$CONFIGFILE"
 #
 # SSID setting.
 # Validate new SSID. Replace it with 'MoodleBox' if invalid.
-[[ $NEWSSID =~ ^[[:alnum:][:blank:]]{1,32}$ ]] || NEWSSID="MoodleBox"
+# At this point, $NEWSSID is a string of hex values, e.g. "74657374" for "test"
+# We want to check that it is valid, and between 8 and 32 bytes.
+[[ $NEWSSID =~ ^([0-9a-fA-F]{2}){8,32}$ ]] || NEWSSID="4d6f6f646c65426f78" # "MoodleBox"
 # New SSID is now valid; set it in config file.
-if [[ -z $(grep "^utf8_ssid=1$" "$CONFIGFILE") ]]; then # Change ssid to ssid2, add utf8_ssid param.
-    sed -i "/^ssid=/c\ssid2=P\"$NEWSSID\"" "$CONFIGFILE"
+# Change ssid to ssid2
+sed -i "/^ssid=/c\ssid2=$NEWSSID" "$CONFIGFILE"
+sed -i "/^ssid2=/c\ssid2=$NEWSSID" "$CONFIGFILE"
+if [[ -z $(grep "^utf8_ssid=1$" "$CONFIGFILE") ]]; then # add utf8_ssid param.
     sed -i "/ssid2/a utf8_ssid=1" "$CONFIGFILE"
-else
-    sed -i "/^ssid2=/c\ssid2=P\"$NEWSSID\"" "$CONFIGFILE"
 fi
 #
 # Password protection setting.
diff --git a/index.php b/index.php
index 760dafb..4c25363 100644
--- a/index.php
+++ b/index.php
@@ -136,9 +136,12 @@
     $wifiinfo = \tool_moodlebox\local\utils::parse_config_file('/etc/hostapd/hostapd.conf', false, INI_SCANNER_RAW);
 
     $currentwifichannel = $wifiinfo['channel'];
-    $currentwifissid = array_key_exists('ssid', $wifiinfo) ? $wifiinfo['ssid'] : $wifiinfo['ssid2'];
-    if ( preg_match_all('/"([^"]+)"/', $currentwifissid, $ssidmatch) ) {
-        $currentwifissid = $ssidmatch[1][0];
+    if ( array_key_exists('ssid', $wifiinfo) ) {
+        $currentwifissid = $wifiinfo['ssid'];
+    } else {
+        $currentwifissid = $wifiinfo['ssid2'];
+        // Convert $currentwifissid from hex. See https://stackoverflow.com/a/46344675.
+        $currentwifissid = pack("H*", $currentwifissid);
     }
     $currentwifipassword = array_key_exists('wpa_passphrase', $wifiinfo) ? $wifiinfo['wpa_passphrase'] : null;
     $currentwificountry = $wifiinfo['country_code'];
@@ -406,6 +409,8 @@ public function definition() {
                 if (!isset($data->wifipassword)) {
                     $data->wifipassword = null;
                 }
+                // Convert $data->wifissid to hex. See https://stackoverflow.com/a/46344675.
+                $data->wifissid = implode(unpack("H*", $data->wifissid));
                 file_put_contents($wifipasswordtriggerfilename,
                                   "channel=" . $data->wifichannel . "\n" .
                                   "password=" . $data->wifipassword . "\n" .