Drop out channel hash helper

app/decoder.py

@@ -85,15 +85,6 @@ class PacketInfo:
     path_hash_size: int = 1  # Bytes per hop: 1, 2, or 3
 
 
-def calculate_channel_hash(channel_key: bytes) -> str:
-    """
-    Calculate the channel hash from a 16-byte channel key.
-    Returns the first byte of SHA256(key) as hex.
-    """
-    hash_bytes = hashlib.sha256(channel_key).digest()
-    return format(hash_bytes[0], "02x")
-
-
 def extract_payload(raw_packet: bytes) -> bytes | None:
     """
     Extract just the payload from a raw packet, skipping header and path.
@@ -233,7 +224,7 @@ def try_decrypt_packet_with_channel_key(
         return None
 
     packet_channel_hash = format(packet_info.payload[0], "02x")
-    expected_hash = calculate_channel_hash(channel_key)
+    expected_hash = format(hashlib.sha256(channel_key).digest()[0], "02x")
 
     if packet_channel_hash != expected_hash:
         return None

app/repository/messages.py

@@ -857,6 +857,19 @@ class MessageRepository:
             "top_senders_24h": top_senders,
         }
 
+    @staticmethod
+    async def count_channels_with_incoming_messages() -> int:
+        """Count distinct channel conversations with at least one incoming message."""
+        cursor = await db.conn.execute(
+            """
+            SELECT COUNT(DISTINCT conversation_key) AS cnt
+            FROM messages
+            WHERE type = 'CHAN' AND outgoing = 0
+            """
+        )
+        row = await cursor.fetchone()
+        return int(row["cnt"]) if row and row["cnt"] is not None else 0
+
     @staticmethod
     async def get_most_active_rooms(sender_key: str, limit: int = 5) -> list[tuple[str, str, int]]:
         """Get channels where a contact has sent the most messages.

app/routers/debug.py

@@ -13,6 +13,7 @@ from pydantic import BaseModel, Field
 
 from app.config import get_recent_log_lines, settings
 from app.radio_sync import get_contacts_selected_for_radio_sync, get_radio_channel_limit
+from app.repository import MessageRepository
 from app.routers.health import HealthResponse, build_health_data
 from app.services.radio_runtime import radio_runtime
 
@@ -34,6 +35,7 @@ class DebugRuntimeInfo(BaseModel):
     connection_desired: bool
     setup_in_progress: bool
     setup_complete: bool
+    channels_with_incoming_messages: int
     max_channels: int
     path_hash_mode: int
     path_hash_mode_supported: bool
@@ -269,6 +271,9 @@ async def debug_support_snapshot() -> DebugSnapshotResponse:
     """Return a support/debug snapshot with recent logs and live radio state."""
     health_data = await build_health_data(radio_runtime.is_connected, radio_runtime.connection_info)
     radio_probe = await _probe_radio()
+    channels_with_incoming_messages = (
+        await MessageRepository.count_channels_with_incoming_messages()
+    )
     return DebugSnapshotResponse(
         captured_at=datetime.now(timezone.utc).isoformat(),
         application=_build_application_info(),
@@ -278,6 +283,7 @@ async def debug_support_snapshot() -> DebugSnapshotResponse:
             connection_desired=radio_runtime.connection_desired,
             setup_in_progress=radio_runtime.is_setup_in_progress,
             setup_complete=radio_runtime.is_setup_complete,
+            channels_with_incoming_messages=channels_with_incoming_messages,
             max_channels=radio_runtime.max_channels,
             path_hash_mode=radio_runtime.path_hash_mode,
             path_hash_mode_supported=radio_runtime.path_hash_mode_supported,

app/routers/messages.py

@@ -138,7 +138,6 @@ async def send_channel_message(request: SendChannelMessageRequest) -> Message:
     require_connected()
 
     # Get channel info from our database
-    from app.decoder import calculate_channel_hash
     from app.repository import ChannelRepository
 
     db_channel = await ChannelRepository.get_by_key(request.channel_key)
@@ -155,13 +154,6 @@ async def send_channel_message(request: SendChannelMessageRequest) -> Message:
             status_code=400, detail=f"Invalid channel key format: {request.channel_key}"
         ) from None
 
-    expected_hash = calculate_channel_hash(key_bytes)
-    logger.info(
-        "Sending to channel %s (%s) via managed radio slot, key hash: %s",
-        request.channel_key,
-        db_channel.name,
-        expected_hash,
-    )
     return await send_channel_message_to_channel(
         channel=db_channel,
         channel_key_upper=request.channel_key.upper(),

tests/test_api.py

@@ -127,6 +127,13 @@ class TestDebugEndpoint:
         channel_key = "CD" * 16
         await _insert_contact(contact_key, "Alice", last_contacted=1700000000)
         await ChannelRepository.upsert(key=channel_key, name="#flightless", on_radio=False)
+        await MessageRepository.create(
+            msg_type="CHAN",
+            text="Alice: hello",
+            received_at=1700000001,
+            conversation_key=channel_key,
+            sender_timestamp=1700000001,
+        )
 
         radio_manager.max_channels = 2
         radio_manager.path_hash_mode = 1
@@ -187,6 +194,7 @@ class TestDebugEndpoint:
 
         assert payload["application"]["commit_hash"] == "deadbeef"
         assert payload["runtime"]["channel_slot_reuse_enabled"] is True
+        assert payload["runtime"]["channels_with_incoming_messages"] == 1
         assert any("support snapshot marker" in line for line in payload["logs"])
 
         radio_probe = payload["radio_probe"]
@@ -226,6 +234,7 @@ class TestDebugEndpoint:
         payload = response.json()
         assert payload["radio_probe"]["performed"] is False
         assert payload["radio_probe"]["errors"] == ["Radio not connected"]
+        assert payload["runtime"]["channels_with_incoming_messages"] == 0
 
 
 class TestRadioDisconnectedHandler:
@@ -328,7 +337,6 @@ class TestMessagesEndpoint:
         radio_manager._meshcore = mock_mc
         with (
             _patch_require_connected(mock_mc),
-            patch("app.decoder.calculate_channel_hash", return_value="abcd"),
             patch("app.routers.messages.broadcast_event") as mock_broadcast,
         ):
             response = await client.post(

tests/test_decoder.py

@@ -14,7 +14,6 @@ from app.decoder import (
     PayloadType,
     RouteType,
     _clamp_scalar,
-    calculate_channel_hash,
     decrypt_direct_message,
     decrypt_group_text,
     derive_public_key,
@@ -34,22 +33,8 @@ class TestChannelKeyDerivation:
         channel_name = "#test"
         expected_key = hashlib.sha256(channel_name.encode("utf-8")).digest()[:16]
 
-        # Verify the derived key produces the expected channel hash
-        result_hash = calculate_channel_hash(expected_key)
-        expected_hash = format(hashlib.sha256(expected_key).digest()[0], "02x")
-        assert result_hash == expected_hash
         assert len(expected_key) == 16
 
-    def test_channel_hash_calculation(self):
-        """Channel hash is the first byte of SHA256(key) as hex."""
-        key = bytes(16)  # All zeros
-        expected_hash = format(hashlib.sha256(key).digest()[0], "02x")
-
-        result = calculate_channel_hash(key)
-
-        assert result == expected_hash
-        assert len(result) == 2  # Two hex chars
-
 
 class TestPacketParsing:
     """Test raw packet header parsing."""

tests/test_real_crypto.py

@@ -210,12 +210,10 @@ class TestChannelDecryption:
 
     def test_channel_hash_matches_packet(self):
         """Channel hash in packet matches hash computed from key."""
-        from app.decoder import calculate_channel_hash
-
         info = parse_packet(CHANNEL_PACKET)
         assert info is not None
         packet_hash = format(info.payload[0], "02x")
-        expected_hash = calculate_channel_hash(CHANNEL_KEY)
+        expected_hash = format(sha256(CHANNEL_KEY).digest()[0], "02x")
         assert packet_hash == expected_hash
 
     def test_wrong_channel_key_fails(self):

tests/test_send_messages.py

@@ -209,7 +209,6 @@ class TestOutgoingChannelBroadcast:
         with (
             patch("app.routers.messages.require_connected", return_value=mc),
             patch.object(radio_manager, "_meshcore", mc),
-            patch("app.decoder.calculate_channel_hash", return_value="abcd"),
             patch("app.routers.messages.broadcast_event", side_effect=capture_broadcast),
         ):
             request = SendChannelMessageRequest(channel_key=chan_key, text="!lasttime5 someone")
@@ -234,7 +233,6 @@ class TestOutgoingChannelBroadcast:
         with (
             patch("app.routers.messages.require_connected", return_value=mc),
             patch.object(radio_manager, "_meshcore", mc),
-            patch("app.decoder.calculate_channel_hash", return_value="abcd"),
             patch("app.routers.messages.broadcast_event"),
         ):
             request = SendChannelMessageRequest(channel_key=chan_key, text="acked now")
@@ -262,7 +260,6 @@ class TestOutgoingChannelBroadcast:
         with (
             patch("app.routers.messages.require_connected", return_value=mc),
             patch.object(radio_manager, "_meshcore", mc),
-            patch("app.decoder.calculate_channel_hash", return_value="abcd"),
             patch("app.routers.messages.broadcast_event", side_effect=capture_broadcast),
         ):
             request = SendChannelMessageRequest(channel_key=chan_key, text="hello")
@@ -293,7 +290,6 @@ class TestOutgoingChannelBroadcast:
         with (
             patch("app.routers.messages.require_connected", return_value=mc),
             patch.object(radio_manager, "_meshcore", mc),
-            patch("app.decoder.calculate_channel_hash", return_value="abcd"),
             patch("app.routers.messages.broadcast_event"),
         ):
             request = SendChannelMessageRequest(channel_key=chan_key, text="hello")
@@ -317,7 +313,6 @@ class TestOutgoingChannelBroadcast:
         with (
             patch("app.routers.messages.require_connected", return_value=mc),
             patch.object(radio_manager, "_meshcore", mc),
-            patch("app.decoder.calculate_channel_hash", return_value="abcd"),
             patch("app.routers.messages.broadcast_event"),
         ):
             request = SendChannelMessageRequest(channel_key=chan_key, text="hello")
@@ -339,7 +334,6 @@ class TestOutgoingChannelBroadcast:
         with (
             patch("app.routers.messages.require_connected", return_value=mc),
             patch.object(radio_manager, "_meshcore", mc),
-            patch("app.decoder.calculate_channel_hash", return_value="abcd"),
             patch("app.routers.messages.broadcast_event"),
             pytest.raises(HTTPException) as exc_info,
         ):
@@ -362,7 +356,6 @@ class TestOutgoingChannelBroadcast:
         with (
             patch("app.routers.messages.require_connected", return_value=mc),
             patch.object(radio_manager, "_meshcore", mc),
-            patch("app.decoder.calculate_channel_hash", return_value="abcd"),
             patch("app.routers.messages.broadcast_event"),
         ):
             await send_channel_message(
@@ -391,7 +384,6 @@ class TestOutgoingChannelBroadcast:
         with (
             patch("app.routers.messages.require_connected", return_value=mc),
             patch.object(radio_manager, "_meshcore", mc),
-            patch("app.decoder.calculate_channel_hash", return_value="abcd"),
             patch("app.routers.messages.broadcast_event"),
         ):
             await send_channel_message(
@@ -433,7 +425,6 @@ class TestOutgoingChannelBroadcast:
         with (
             patch("app.routers.messages.require_connected", return_value=mc),
             patch.object(radio_manager, "_meshcore", mc),
-            patch("app.decoder.calculate_channel_hash", return_value="abcd"),
             patch("app.routers.messages.broadcast_event"),
         ):
             await send_channel_message(
@@ -458,7 +449,6 @@ class TestOutgoingChannelBroadcast:
         with (
             patch("app.routers.messages.require_connected", return_value=mc),
             patch.object(radio_manager, "_meshcore", mc),
-            patch("app.decoder.calculate_channel_hash", return_value="abcd"),
             patch("app.routers.messages.broadcast_event"),
             patch("app.radio.settings.force_channel_slot_reconfigure", True),
         ):
@@ -487,7 +477,6 @@ class TestOutgoingChannelBroadcast:
         with (
             patch("app.routers.messages.require_connected", return_value=mc),
             patch.object(radio_manager, "_meshcore", mc),
-            patch("app.decoder.calculate_channel_hash", return_value="abcd"),
             patch("app.routers.messages.broadcast_event"),
             pytest.raises(HTTPException) as exc_info,
         ):