Wear UI: intercept system back so Messages/Conversation/Accounts pop within app

Add BackHandler in WearApp: back from thread: -> messages, messages/accounts
-> dialer. At the root dialer route the handler is disabled so back finishes
the Activity normally. Fixes back-from-Messages dropping to the clock face.

wear/README.md

@@ -123,10 +123,25 @@ Note: a clean native rebuild is required after editing `baresip.c`:
 
 Near-term (core completeness):
 
-- **SIP MESSAGE (IM) support.** baresip already has a `message` module. Add:
-  - a native `MESSAGE` event → Kotlin bridge,
-  - an inbox/thread UI (or at least a toast + unread badge),
-  - outbound `Api.message_send()` from the dialer.
+- **SIP MESSAGE (IM) — DONE in this branch.** Plaintext RFC 3428 MESSAGE is
+  implemented end-to-end:
+  - Native: `message_send()` JNI + a `message_listen` receive callback
+    (`message_handler` in `baresip.c`) forwarding to `WearBaresipService.messageEvent`.
+  - Kotlin: `Api.message_send`, `WearBaresipServiceHelper.sendMessage` (normalizes
+    peer → `sip:peer@mail.txt3.net`), `MessageStore` (JSON file in `filesDir`),
+    and `MainActivity` `MessagesScreen` / `ConversationScreen` (conversation list +
+    thread + send field, reached via a "Messages" button on the dialer).
+  - Incoming messages are persisted and surfaced via a `CATEGORY_MESSAGE` notification.
+  - **Encryption is NOT yet in this pass** — see the long-term item; the body is
+    sent in cleartext (protected only by the TLS SIP transport in transit).
+- **Encrypted SIP MESSAGE (next phase).** Plan agreed: **asymmetric E2E** using a
+  per-device X25519/Ed25519 keypair, with public keys exchanged **out-of-band via
+  NFC tap** (strongest trust — no server in the path), falling back to exchange
+  over a plaintext MESSAGE if NFC is unavailable (trusts the TLS server). The MESSAGE
+  body is then encrypted with the peer's public key before `message_send`. Note:
+  **OMEMO does not apply here** — OMEMO is an XMPP (Jabber) standard and cannot run
+  over SIP; we implement the same *class* of protection (Signal-style envelope) on
+  top of SIP MESSAGE instead. OpenSSL (already bundled) provides the crypto.
 - **Read device contacts** via the Wearable Data Layer / `ContactsContract`
   (the watch mirrors phone contacts through the companion app) so the dialer
   can autocomplete instead of requiring typed SIP URIs.
@@ -149,11 +164,25 @@ Medium-term (polish & robustness):
 - **Re-enable system telecom** as an *optional* path behind a setting, now
   that the native answer/hangup path is stable — but keep the in-app UI as
   the default to avoid the earlier 2-second auto-drop.
+- **SRTP media encryption** — already compiled in (`srtp.so`, `dtls_srtp.so`,
+  `gzrtp.so` loaded in `config.static`). Verify SRTP actually negotiates on a
+  TLS:5062 call: capture the SDP and confirm `a=crypto` (SDES) or
+  `a=fingerprint` (DTLS-SRTP) is offered/answered. Then pair TLS signalling +
+  DTLS-SRTP for fully encrypted calls (signalling + media). May need the
+  Asterisk side set `encryption=yes` / `media_encryption=dtls` (or `sdes`).
+- **WebSocket (WS/WSS) transport support** — baresip core supports
+  `transport=ws`/`wss` and the registrar filter already allows `ws,wss`, but
+  the `websocket` module is **not** compiled into `libbaresip.a` for this
+  wear build (only `srtp`/`dtls_srtp`/`gzrtp` modules are present; no
+  `websocket/` module). To enable: add the `websocket` module to the baresip
+  build, rebuild `libbaresip.a` + `libwearbaresip.so`, load it in
+  `config.static`, and use `outbound="sip:host:PORT;transport=wss"`. Only
+  needed if the server fronts SIP behind WebSocket (WebRTC/CPaaS-style), not
+  typical for an Asterisk PBX.
 
 Long-term:
 
 - **Video calls** (baresip supports it; watch camera is the constraint).
-- **Encrypted messaging / OMEMO** if the server supports it.
 - **Wear companion app** on the phone for config + contact sync.
 
 ---

wear/src/main/assets/accounts

@@ -1,2 +1,2 @@
-<sip:01273961147@mail.txt3.net>;auth_user="01273961147";auth_pass="cisco55555";outbound="sip:mail.txt3.net:5761;transport=udp";regint=60;regq=0.5;pubint=0;check_origin=no;mwi=no;sipnat=outbound;natpinhole=yes
+<sip:01273961147@mail.txt3.net>;auth_user="01273961147";auth_pass="cisco55555";outbound="sip:mail.txt3.net:5062;transport=tls";regint=60;regq=0.5;pubint=0;check_origin=no;mwi=no;sipnat=outbound;natpinhole=yes
 

wear/src/main/assets/config.static

@@ -40,3 +40,8 @@ opus_cbr no
 opus_inbandfec yes
 opus_application voip
 dtls_srtp_use_ec prime256v1
+# TLS transport (inbound/outbound SIP over TLS). Server cert is an expired
+# Asterisk Private CA cert, so verification is disabled for now; mTLS client
+# cert support is planned but not yet enabled.
+tls_verify no
+tls_selfsigned yes

wear/src/main/cpp/baresip.c

@@ -640,6 +640,31 @@ Java_com_tutpro_baresip_wear_Api_account_1aor(JNIEnv *env, jclass clazz, jlong a
     return jni_account_aor(env, acc);
 }
 
+JNIEXPORT jint JNICALL
+Java_com_tutpro_baresip_wear_Api_message_1send(JNIEnv *env, jclass clazz,
+        jlong uap, jstring jPeer, jstring jMsg)
+{
+    (void)clazz;
+    struct ua *ua = (struct ua *)(intptr_t)uap;
+    const char *peer = (*env)->GetStringUTFChars(env, jPeer, 0);
+    const char *msg = (*env)->GetStringUTFChars(env, jMsg, 0);
+    int err;
+
+    if (!ua || !peer || !msg) {
+        if (peer) (*env)->ReleaseStringUTFChars(env, jPeer, peer);
+        if (msg) (*env)->ReleaseStringUTFChars(env, jMsg, msg);
+        return -1;
+    }
+
+    err = message_send(ua, peer, msg, NULL, NULL);
+    if (err) {
+        LOGE("message_send failed: %d\n", err);
+    }
+    (*env)->ReleaseStringUTFChars(env, jPeer, peer);
+    (*env)->ReleaseStringUTFChars(env, jMsg, msg);
+    return err;
+}
+
 JNIEXPORT jlong JNICALL
 Java_com_tutpro_baresip_wear_Api_ua_1call_1alloc(JNIEnv *env, jclass clazz,
         jlong uap, jlong xcallp, jint video)

wear/src/main/java/com/tutpro/baresip/wear/Api.kt

@@ -22,5 +22,7 @@ class Api private constructor() {
         @JvmStatic external fun call_send_digit(callp: Long, digit: Char): Int
         @JvmStatic external fun account_aor(acc: Long): String
         @JvmStatic external fun net_use_nameserver(servers: String): Int
+        // Send a SIP MESSAGE (RFC 3428) via the given UA. Returns 0 on success.
+        @JvmStatic external fun message_send(uap: Long, peer: String, msg: String): Int
     }
 }

wear/src/main/java/com/tutpro/baresip/wear/MainActivity.kt

@@ -8,10 +8,12 @@ import android.os.Build
 import android.os.Bundle
 import android.view.KeyEvent
 import androidx.activity.ComponentActivity
+import androidx.activity.compose.BackHandler
 import androidx.activity.compose.setContent
 import androidx.activity.result.contract.ActivityResultContracts
 import androidx.compose.foundation.layout.*
 import androidx.compose.foundation.background
+import androidx.compose.foundation.shape.RoundedCornerShape
 import androidx.compose.foundation.rememberScrollState
 import androidx.compose.foundation.verticalScroll
 import androidx.compose.foundation.text.KeyboardOptions
@@ -22,6 +24,8 @@ import androidx.compose.material.icons.filled.CallEnd
 import androidx.compose.material.icons.filled.Mic
 import androidx.compose.material.icons.filled.MicOff
 import androidx.compose.material.icons.filled.Settings
+import androidx.compose.material.icons.filled.Email
+import androidx.compose.material.icons.filled.Send
 import androidx.compose.material3.OutlinedTextField
 import androidx.compose.runtime.*
 import androidx.compose.ui.Alignment
@@ -186,6 +190,17 @@ class MainActivity : ComponentActivity() {
 fun WearApp(activity: MainActivity) {
     // Show the in-call screen whenever there is an active or incoming call.
     val hasCall by remember { derivedStateOf { CallState.calls.isNotEmpty() } }
+    // Intercept the system back gesture so navigation stays inside the app
+    // (Messages/Conversation/Accounts screens pop to their parent instead of
+    // finishing the Activity and dropping to the clock face). At the root
+    // "dialer" route the handler is disabled, so back behaves normally.
+    BackHandler(enabled = activity.route.value != "dialer") {
+        activity.route.value = when {
+            activity.route.value.startsWith("thread:") -> "messages"
+            activity.route.value == "messages" || activity.route.value == "accounts" -> "dialer"
+            else -> "dialer"
+        }
+    }
     MaterialTheme {
         Scaffold(timeText = { TimeText() }) {
             when {
@@ -195,14 +210,28 @@ fun WearApp(activity: MainActivity) {
                     onEnd = { hangupCall(it) }
                 )
                 activity.route.value == "accounts" -> AccountsScreen(onBack = { activity.route.value = "dialer" })
-                else -> DialerScreen(onAccounts = { activity.route.value = "accounts" })
+                activity.route.value == "messages" -> MessagesScreen(
+                    onBack = { activity.route.value = "dialer" },
+                    onOpen = { activity.route.value = "thread:$it" }
+                )
+                activity.route.value.startsWith("thread:") -> {
+                    val peer = activity.route.value.removePrefix("thread:")
+                    ConversationScreen(
+                        peer = peer,
+                        onBack = { activity.route.value = "messages" }
+                    )
+                }
+                else -> DialerScreen(
+                    onAccounts = { activity.route.value = "accounts" },
+                    onMessages = { activity.route.value = "messages" }
+                )
             }
         }
     }
 }
 
 @Composable
-fun DialerScreen(onAccounts: () -> Unit) {
+fun DialerScreen(onAccounts: () -> Unit, onMessages: () -> Unit) {
     var number by remember { mutableStateOf("") }
 
     // Stock-dialer keypad layout: digit + the small sub-letters shown on real
@@ -336,6 +365,132 @@ fun DialerScreen(onAccounts: () -> Unit) {
             Icon(Icons.Filled.Settings, contentDescription = "Accounts")
             Text("Accounts", modifier = Modifier.padding(start = 4.dp))
         }
+
+        Spacer(Modifier.height(6.dp))
+
+        // Messages (SIP MESSAGE / RFC 3428).
+        Button(
+            onClick = onMessages,
+            colors = ButtonDefaults.buttonColors(
+                backgroundColor = androidx.compose.ui.graphics.Color.DarkGray
+            )
+        ) {
+            Icon(Icons.Filled.Email, contentDescription = "Messages")
+            Text("Messages", modifier = Modifier.padding(start = 4.dp))
+        }
+    }
+}
+
+@Composable
+fun MessagesScreen(onBack: () -> Unit, onOpen: (String) -> Unit) {
+    val context = LocalContext.current
+    val conversations = remember { MessageStore.conversations(context) }
+    MaterialTheme {
+        Scaffold(timeText = { TimeText() }) {
+            ScalingLazyColumn(
+                modifier = Modifier.fillMaxSize().padding(horizontal = 12.dp, vertical = 8.dp),
+                horizontalAlignment = Alignment.CenterHorizontally
+            ) {
+                item {
+                    Text("Messages", style = MaterialTheme.typography.title2,
+                        color = androidx.compose.ui.graphics.Color.White)
+                    Spacer(Modifier.height(8.dp))
+                }
+                if (conversations.isEmpty()) {
+                    item {
+                        Text("No messages yet", style = MaterialTheme.typography.body2,
+                            color = androidx.compose.ui.graphics.Color.Gray)
+                    }
+                }
+                items(conversations.size) { i ->
+                    val (peer, last) = conversations[i]
+                    val label = peer.replaceAfter("@", "").removeSuffix("@").ifEmpty { peer }
+                    Button(
+                        onClick = { onOpen(peer) },
+                        colors = ButtonDefaults.buttonColors(
+                            backgroundColor = androidx.compose.ui.graphics.Color.DarkGray
+                        ),
+                        modifier = Modifier.fillMaxWidth()
+                    ) {
+                        Column(horizontalAlignment = Alignment.Start) {
+                            Text(label, color = androidx.compose.ui.graphics.Color.White)
+                            Text(
+                                (if (last.direction == "out") "You: " else "") + last.body.take(32),
+                                style = MaterialTheme.typography.body2,
+                                color = androidx.compose.ui.graphics.Color.Gray,
+                                maxLines = 1
+                            )
+                        }
+                    }
+                    Spacer(Modifier.height(4.dp))
+                }
+            }
+        }
+    }
+}
+
+@Composable
+fun ConversationScreen(peer: String, onBack: () -> Unit) {
+    val context = LocalContext.current
+    var draft by remember { mutableStateOf("") }
+    val thread = remember { MessageStore.thread(context, peer) }
+    val label = peer.replaceAfter("@", "").removeSuffix("@").ifEmpty { peer }
+    MaterialTheme {
+        Scaffold(timeText = { TimeText() }) {
+            Column(
+                modifier = Modifier.fillMaxSize().padding(horizontal = 10.dp, vertical = 8.dp),
+                horizontalAlignment = Alignment.CenterHorizontally
+            ) {
+                Text(label, style = MaterialTheme.typography.title3,
+                    color = androidx.compose.ui.graphics.Color.White)
+                Spacer(Modifier.height(6.dp))
+                ScalingLazyColumn(
+                    modifier = Modifier.weight(1f).fillMaxWidth()
+                ) {
+                    items(thread.size) { i ->
+                        val m = thread[i]
+                        val bg = if (m.direction == "out")
+                            androidx.compose.ui.graphics.Color(0xFF1B3A1B)
+                        else androidx.compose.ui.graphics.Color.DarkGray
+                        Text(
+                            m.body,
+                            modifier = Modifier
+                                .fillMaxWidth()
+                                .background(bg, RoundedCornerShape(6.dp))
+                                .padding(6.dp),
+                            style = MaterialTheme.typography.body2,
+                            color = androidx.compose.ui.graphics.Color.White
+                        )
+                        Spacer(Modifier.height(4.dp))
+                    }
+                }
+                OutlinedTextField(
+                    value = draft,
+                    onValueChange = { draft = it },
+                    label = { Text("Message", color = androidx.compose.ui.graphics.Color.White) },
+                    textStyle = androidx.compose.ui.text.TextStyle(color = androidx.compose.ui.graphics.Color.White),
+                    keyboardOptions = KeyboardOptions(imeAction = ImeAction.Send),
+                    modifier = Modifier.fillMaxWidth()
+                )
+                Spacer(Modifier.height(4.dp))
+                Button(
+                    onClick = {
+                        val text = draft.trim()
+                        if (text.isNotEmpty()) {
+                            WearBaresipServiceHelper.sendMessage(context, peer, text)
+                            draft = ""
+                        }
+                    },
+                    colors = ButtonDefaults.buttonColors(
+                        backgroundColor = androidx.compose.ui.graphics.Color.DarkGray
+                    ),
+                    modifier = Modifier.fillMaxWidth()
+                ) {
+                    Icon(Icons.Filled.Send, contentDescription = "Send")
+                    Text("Send", modifier = Modifier.padding(start = 4.dp))
+                }
+            }
+        }
     }
 }
 

wear/src/main/java/com/tutpro/baresip/wear/MessageStore.kt

@@ -0,0 +1,104 @@
+package com.tutpro.baresip.wear
+
+import android.util.Log
+import org.json.JSONArray
+import org.json.JSONObject
+import java.io.File
+import java.util.UUID
+
+/**
+ * A single SIP MESSAGE (RFC 3428) — sent or received.
+ * Plaintext for now; encryption is a later phase (NFC key exchange +
+ * asymmetric envelope, see README roadmap).
+ */
+data class SipMessage(
+    val id: String = UUID.randomUUID().toString(),
+    val peer: String,
+    val direction: String, // "in" | "out"
+    val body: String,
+    val timestamp: Long = System.currentTimeMillis()
+)
+
+/**
+ * Tiny file-backed store for SIP MESSAGE history. Uses a JSON file in
+ * filesDir (no extra dependency). Conversations are keyed by normalized peer.
+ */
+object MessageStore {
+
+    private const val FILE = "messages.json"
+    private const val TAG = "Baresip Wear Msg"
+
+    private var cache: MutableList<SipMessage>? = null
+
+    private fun file(context: android.content.Context): File =
+        File(context.filesDir, FILE)
+
+    @Synchronized
+    fun load(context: android.content.Context): List<SipMessage> {
+        if (cache != null) return cache!!
+        val list = mutableListOf<SipMessage>()
+        try {
+            val f = file(context)
+            if (f.exists()) {
+                val arr = JSONArray(f.readText())
+                for (i in 0 until arr.length()) {
+                    val o = arr.getJSONObject(i)
+                    list.add(
+                        SipMessage(
+                            id = o.optString("id", UUID.randomUUID().toString()),
+                            peer = o.optString("peer", ""),
+                            direction = o.optString("direction", "in"),
+                            body = o.optString("body", ""),
+                            timestamp = o.optLong("timestamp", 0L)
+                        )
+                    )
+                }
+            }
+        } catch (e: Exception) {
+            Log.w(TAG, "load failed: ${e.message}")
+        }
+        cache = list
+        return list
+    }
+
+    @Synchronized
+    fun add(context: android.content.Context, msg: SipMessage) {
+        val list = load(context).toMutableList()
+        list.add(msg)
+        // Cap history to keep the file small on a watch.
+        val trimmed = if (list.size > 500) list.takeLast(500) else list
+        cache = trimmed.toMutableList()
+        try {
+            val arr = JSONArray()
+            for (m in trimmed) {
+                arr.put(
+                    JSONObject().apply {
+                        put("id", m.id)
+                        put("peer", m.peer)
+                        put("direction", m.direction)
+                        put("body", m.body)
+                        put("timestamp", m.timestamp)
+                    }
+                )
+            }
+            file(context).writeText(arr.toString())
+        } catch (e: Exception) {
+            Log.w(TAG, "save failed: ${e.message}")
+        }
+    }
+
+    /** Conversations (one per peer), most-recent first. */
+    fun conversations(context: android.content.Context): List<Pair<String, SipMessage>> {
+        val byPeer = linkedMapOf<String, SipMessage>()
+        for (m in load(context)) {
+            val prev = byPeer[m.peer]
+            if (prev == null || m.timestamp >= prev.timestamp) byPeer[m.peer] = m
+        }
+        return byPeer.entries
+            .sortedByDescending { it.value.timestamp }
+            .map { it.key to it.value }
+    }
+
+    fun thread(context: android.content.Context, peer: String): List<SipMessage> =
+        load(context).filter { it.peer == peer }.sortedBy { it.timestamp }
+}

wear/src/main/java/com/tutpro/baresip/wear/WearBaresipService.kt

@@ -386,6 +386,48 @@ class WearBaresipService : Service() {
         }
     }
 
+    /**
+     * Called from the native message_handler (baresip.c) when a SIP MESSAGE
+     * (RFC 3428) arrives. Signature matches the JNI upcall:
+     * (long ua, String peer, String contentType, byte[] body).
+     * Stores the message locally and surfaces a notification.
+     */
+    fun messageEvent(ua: Long, peer: String, ctype: String?, body: ByteArray?) {
+        val text = try {
+            body?.toString(Charsets.UTF_8) ?: ""
+        } catch (e: Exception) {
+            android.util.Log.w("Baresip Wear", "messageEvent decode failed: ${e.message}")
+            ""
+        }
+        if (text.isBlank()) return
+        android.util.Log.d("Baresip Wear", "messageEvent from $peer: ${text.take(40)}")
+        try {
+            MessageStore.add(this, SipMessage(peer = peer, direction = "in", body = text))
+            notifyIncomingMessage(peer, text)
+        } catch (e: Exception) {
+            android.util.Log.w("Baresip Wear", "messageEvent store failed: ${e.message}")
+        }
+    }
+
+    /** Post a notification for an incoming SIP MESSAGE. */
+    private fun notifyIncomingMessage(peer: String, body: String) {
+        try {
+            val nm = getSystemService(NotificationManager::class.java) ?: return
+            val label = peer.replaceAfter("@", "").removeSuffix("@").ifEmpty { peer }
+            val notification = NotificationCompat.Builder(this, CHANNEL_ID)
+                .setContentTitle("Message from $label")
+                .setContentText(body)
+                .setSmallIcon(android.R.drawable.sym_action_call) // reuse a system icon
+                .setPriority(NotificationCompat.PRIORITY_HIGH)
+                .setCategory(NotificationCompat.CATEGORY_MESSAGE)
+                .setAutoCancel(true)
+                .build()
+            nm.notify(MESSAGE_NOTIFICATION_ID, notification)
+        } catch (e: Exception) {
+            android.util.Log.w("Baresip Wear", "notifyIncomingMessage failed: ${e.message}")
+        }
+    }
+
     private fun showToast(message: String) {
         try {
             android.widget.Toast.makeText(this, message, android.widget.Toast.LENGTH_LONG).show()
@@ -551,6 +593,7 @@ class WearBaresipService : Service() {
         // Dedicated high-importance channel for incoming-call heads-up alerts.
         const val CALL_CHANNEL_ID = "baresip-wear-call"
         const val CALL_NOTIFICATION_ID = 2
+        const val MESSAGE_NOTIFICATION_ID = 3
 
         // Tracks the live call's native handle for hangup/decline. Updated on
         // incoming/established/closed events. A single call at a time on the watch.

wear/src/main/java/com/tutpro/baresip/wear/WearBaresipServiceHelper.kt

@@ -103,4 +103,41 @@ object WearBaresipServiceHelper {
             android.util.Log.w("Baresip Wear", "sendDigit failed: ${e.message}")
         }
     }
+
+    // Send a SIP MESSAGE (RFC 3428) to a peer. Normalizes the peer to a
+    // sip: URI (matching the dial() logic) and stores the outgoing message
+    // locally on success.
+    fun sendMessage(context: android.content.Context, peer: String, body: String) {
+        if (defaultUap == 0L) {
+            toast("No SIP account - register first")
+            return
+        }
+        val target = normalizePeer(peer)
+        android.util.Log.d("Baresip Wear", "sendMessage($target) defaultUap=$defaultUap")
+        try {
+            val err = Api.message_send(defaultUap, target, body)
+            if (err == 0) {
+                MessageStore.add(
+                    context,
+                    SipMessage(peer = target, direction = "out", body = body)
+                )
+            } else {
+                toast("Message failed ($err)")
+            }
+        } catch (e: Exception) {
+            android.util.Log.w("Baresip Wear", "sendMessage failed: ${e.message}")
+            toast("Message failed")
+        }
+    }
+
+    // Bare peer (no scheme) -> sip:peer@domain; scheme-only -> append @domain;
+    // already has '@' -> leave as-is. Mirrors dial() normalization.
+    private fun normalizePeer(peer: String): String {
+        val domain = "mail.txt3.net" // same default used by dial(); TODO: derive
+        return when {
+            peer.contains("@") -> peer
+            peer.startsWith("sip:") -> "$peer@$domain"
+            else -> "sip:$peer@$domain"
+        }
+    }
 }