Handle multiple groups and other formats of psk

This should address #17.

mobile/src/main/java/be/mygod/vpnhotspot/RepeaterFragment.kt

@@ -245,8 +245,8 @@ class RepeaterFragment : Fragment(), ServiceConnection, Toolbar.OnMenuItemClickL
             val conf = P2pSupplicantConfiguration()
             wifi.SSID = ssid
             wifi.preSharedKey = binder.password
-            if (wifi.preSharedKey == null || wifi.preSharedKey.length < 8) wifi.preSharedKey = conf.readPsk()
+            if (wifi.preSharedKey == null) wifi.preSharedKey = conf.readPsk()
-            if (wifi.preSharedKey != null && wifi.preSharedKey.length >= 8) {
+            if (wifi.preSharedKey != null) {
                 var dialog: WifiP2pDialog? = null
                 dialog = WifiP2pDialog(context, DialogInterface.OnClickListener { _, which ->
                     when (which) {

mobile/src/main/java/be/mygod/vpnhotspot/RepeaterService.kt

@@ -47,6 +47,8 @@ class RepeaterService : Service(), WifiP2pManager.ChannelListener, VpnMonitor.Ca
         val ssid get() = group?.networkName
         val password get() = group?.passphrase
 
+        private var groups: Collection<WifiP2pGroup> = emptyList()
+
         fun startWps(pin: String? = null) {
             if (!active) return
             val wps = WpsInfo()
@@ -67,8 +69,8 @@ class RepeaterService : Service(), WifiP2pManager.ChannelListener, VpnMonitor.Ca
             if (active) removeGroup()
         }
 
-        fun resetCredentials() {
+        fun resetCredentials() = (groups + group).filterNotNull().forEach {
-            p2pManager.deletePersistentGroup(channel, (group ?: return).netId, object : WifiP2pManager.ActionListener {
+            p2pManager.deletePersistentGroup(channel, it.netId, object : WifiP2pManager.ActionListener {
                 override fun onSuccess() = Toast.makeText(this@RepeaterService,
                         R.string.repeater_reset_credentials_success, Toast.LENGTH_SHORT).show()
                 override fun onFailure(reason: Int) = Toast.makeText(this@RepeaterService,
@@ -80,11 +82,8 @@ class RepeaterService : Service(), WifiP2pManager.ChannelListener, VpnMonitor.Ca
             group = null
             try {
                 p2pManager.requestPersistentGroupInfo(channel, {
-                    when (it.size) {
+                    groups = it
-                        0 -> { }
+                    if (it.size == 1) group = it.single()
-                        1 -> group = it.single()
-                        else -> Log.w(TAG, "Unexpected groups: $it")
-                    }
                 })
             } catch (e: ReflectiveOperationException) {
                 e.printStackTrace()

mobile/src/main/java/be/mygod/vpnhotspot/net/wifi/P2pSupplicantConfiguration.kt

@@ -12,16 +12,27 @@ import java.io.File
 class P2pSupplicantConfiguration {
     companion object {
         private const val TAG = "P2pSupplicationConf"
-        // format for ssid is much more complicated, therefore we are only trying to find the line
+        /**
+         * Format for ssid is much more complicated, therefore we are only trying to find the line and rely on
+         * Android's results instead.
+         *
+         * Source: https://android.googlesource.com/platform/external/wpa_supplicant_8/+/2933359/src/utils/common.c#631
+         */
         private val ssidMatcher = "^[\\r\\t ]*ssid=".toRegex()
-        private val pskParser = "^[\\r\\t ]*psk=\"(.*)\"\$".toRegex(RegexOption.MULTILINE)
+        /**
+         * PSK parser can be found here: https://android.googlesource.com/platform/external/wpa_supplicant_8/+/d2986c2/wpa_supplicant/config.c#448
+         */
+        private val pskParser = "^[\\r\\t ]*psk=(ext:|\"(.*)\"|\"(.*)|[0-9a-fA-F]{64})".toRegex(RegexOption.MULTILINE)
     }
 
     private val content by lazy { loggerSu("cat /data/misc/wifi/p2p_supplicant.conf") }
 
     fun readPsk(): String? {
         return try {
-            pskParser.findAll(content ?: return null).single().groupValues[1]
+            val match = pskParser.findAll(content ?: return null).single()
+            val result = match.groupValues[2] + match.groupValues[3]    // only one will match and hold non-empty value
+            check(result.length in 8..63)
+            result
         } catch (e: RuntimeException) {
             Log.w(TAG, content)
             e.printStackTrace()
@@ -34,26 +45,24 @@ class P2pSupplicantConfiguration {
         val content = content ?: return null
         val tempFile = File.createTempFile("vpnhotspot-", ".conf", app.cacheDir)
         try {
-            var ssidFound = false
+            var ssidFound = 0
-            var pskFound = false
+            var pskFound = 0
             tempFile.printWriter().use {
                 for (line in content.lineSequence()) it.println(when {
                     ssidMatcher.containsMatchIn(line) -> {
-                        ssidFound = true
+                        ssidFound += 1
                         "\tssid=" + config.SSID.toByteArray()
                                 .joinToString("") { it.toInt().toString(16).padStart(2, '0') }
                     }
                     pskParser.containsMatchIn(line) -> {
-                        pskFound = true
+                        pskFound += 1
                         "\tpsk=\"${config.preSharedKey}\""  // no control chars or weird stuff
                     }
                     else -> line                            // do nothing
                 })
             }
-            if (!ssidFound || !pskFound) {
+            if (ssidFound != 1 || pskFound != 1) Log.w(TAG, "Invalid conf ($ssidFound, $pskFound): $content")
-                Log.w(TAG, "Invalid conf ($ssidFound, $pskFound): $content")
+            if (ssidFound == 0 || pskFound == 0) return false
-                return false
-            }
             // pkill not available on Lollipop. Source: https://android.googlesource.com/platform/system/core/+/master/shell_and_utilities/README.md
             return noisySu("cat ${tempFile.absolutePath} > /data/misc/wifi/p2p_supplicant.conf",
                     if (Build.VERSION.SDK_INT >= 23) "pkill wpa_supplicant"