Fenrir fixes

[embhorn]

• Fix F-1171 SN_Client_Disconnect_ex check disconnect

• Fix F-1172 SN_Client_Connect clean

• Fix F-1595 use word16 instead of int

• Fix F-1601 check total_len against word16 max

• Fix F-1174 and F-1175 use force zero

• Fix F-1173 SN_Client_WillMsgUpdate debug message

• Fix F-1596 BrokerHandle_Connect packet ID calc

• Fix F-1597 MqttClient_NetDisconnect resp list cleanup

• Fix F-1176 BrokerStrCompare portable constant-time compare

• Fix F-1603 static-mem broker check len

• Fix F-1604 MqttEncode_Props check max props

• Fix F-1606 BrokerHandle_Connect static-mem error codes

[Copilot]

Pull request overview

This PR delivers a batch of targeted robustness and correctness fixes across MQTT-SN, MQTT v5 property encoding, client response lifecycle handling, and broker-side safety checks.

Changes:

• Adds additional length/overflow guards in MQTT-SN packet encoders/decoders and MQTT v5 property encoding.
• Fixes several client/broker correctness issues (pending response cleanup, packet-id wrap handling, debug message type, constant-time compare portability).
• Improves broker-side bounds handling and sensitive-data cleanup (force-zero before free, static-mem length rejection).

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
wolfmqtt/mqtt_sn_packet.h	Introduces SN_PACKET_MAX_LEN (0xFFFF) to bound MQTT-SN packet lengths.
src/mqtt_sn_packet.c	Uses word16 for decoded lengths and enforces max-length checks in multiple MQTT-SN encoders.
src/mqtt_sn_client.c	Fixes pending response cleanup on connect failure, corrects a debug print, and conditions disconnect pendResp handling on sleep timer usage.
src/mqtt_packet.c	Adds property-list corruption guards and remaining-length bounds checks; adds a publish payload/buffer size check.
src/mqtt_client.c	Fixes pending-response list removal loop safety during net disconnect.
src/mqtt_broker.c	Improves constant-time compare portability, adds stricter static-mem length checks, enforces out-of-buffer errors instead of truncation in select paths, and force-zeros sensitive data on free.

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[Copilot]

Pull request overview

Copilot reviewed 7 out of 7 changed files in this pull request and generated 2 comments.

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[Copilot]

Pull request overview

Copilot reviewed 7 out of 7 changed files in this pull request and generated 4 comments.

---

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[wolfSSL-Fenrir-bot]

Fenrir Automated Review — PR #478

Scan targets checked: wolfmqtt-bugs, wolfmqtt-src

Findings: 1
1 finding(s) posted as inline comments (see file-level comments below)

This review was generated automatically by Fenrir. Findings are non-blocking.