Clamp position precision on public / known-keys (#10665)

* Clamp position precision on public / known-keys (Compliance) * Fix review comments: bounds check, all-channel precision clamp, disabled channel guard * Potential fix for pull request finding Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com> * Potential fix for pull request finding Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com> * Refactor position precision comments for clarity and update channel configuration handling in AdminModule * Potential fix for pull request finding Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com> --------- Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com> Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>
2026-06-14 18:53:18 -05:00
parent 8a0c7592cc
commit d878c81ce8
7 changed files with 180 additions and 1 deletions
@@ -404,6 +404,42 @@ bool Channels::isDefaultChannel(ChannelIndex chIndex)
    return false;
 }

+bool cryptoKeyIsPublic(const CryptoKey &key)
+{
+    if (key.length == 0)
+        return true; // encryption disabled
+    // Match the defaultpsk family ignoring its last byte (getKey() bumps only that byte per 1-byte index).
+    if (key.length == (int)sizeof(defaultpsk) && memcmp(key.bytes, defaultpsk, sizeof(defaultpsk) - 1) == 0)
+        return true;
+    return false;
+}
+
+bool Channels::usesPublicKey(ChannelIndex chIndex)
+{
+    const meshtastic_Channel &ch = getByIndex(chIndex);
+    if (!ch.has_settings || ch.role == meshtastic_Channel_Role_DISABLED)
+        return false;
+
+    const auto &psk = ch.settings.psk;
+    if (psk.size == 0) {
+        // Secondary channels inherit the primary key when unset; primary size==0 means encryption disabled.
+        if (ch.role == meshtastic_Channel_Role_SECONDARY) {
+            // Guard against malformed configs with no PRIMARY channel (primaryIndex could point back to us).
+            if (primaryIndex == chIndex)
+                return true; // fail closed: treat as public
+            return usesPublicKey(primaryIndex);
+        }
+        return true;
+    }
+
+    if (psk.size == 1) {
+        // Short PSK aliases: 0 disables encryption; 1..255 are the public defaultpsk family.
+        return true;
+    }
+
+    return (psk.size == sizeof(defaultpsk) && memcmp(psk.bytes, defaultpsk, sizeof(defaultpsk) - 1) == 0);
+}
+
 bool Channels::hasDefaultChannel()
 {
    // If we don't use a preset or the default frequency slot, or we override the frequency, we don't have a default channel