feat(firmware): add secure macOS USB onboarding

(cherry picked from commit 3373e79f38afef3a1430feeb78ae034e78777c66)

.github/workflows/firmware-ci.yml

@@ -92,14 +92,11 @@ jobs:
           idf.py set-target ${{ matrix.target }}
           idf.py build
 
-      - name: Build and run host-side ADR-110 unit tests
+      - name: Build and run host-side firmware unit tests
         if: matrix.variant == 'c6-4mb'
         working-directory: firmware/esp32-csi-node/test
         run: |
-          make test_adr110
+          make host_tests
-          ./test_adr110
-          make test_c6_antenna
-          ./test_c6_antenna
 
       - name: Verify binary size budget
         working-directory: firmware/esp32-csi-node

docs/adr/ADR-348-native-macos-usb-node-onboarding.md

@@ -0,0 +1,79 @@
+# ADR 348: Native macOS USB node onboarding
+
+## Status
+
+Accepted and physically qualified with one attached ESP32 S3 and an unsigned
+Mac Catalyst development build. ESP32 C6 qualification and signed distribution
+remain release gates.
+
+## Context
+
+RuView operators currently provision ESP32 nodes with command line tooling.
+The macOS app can list server accepted node identities, but it cannot establish
+that an attached serial device is RuView firmware, assign a collision free node
+identity, preserve its WiFi configuration, or prove that it joined the sensing
+server. A UI that merely stores a friendly name would create false success.
+
+Generic shell access from the app would also expand authority beyond the task.
+Serial logs can contain operational data, and WiFi credentials must not enter
+application diagnostics or provisioning receipts.
+
+## Decision
+
+1. Firmware 0.8.9 adds a bounded line protocol over the physical USB serial
+   channel. A discovery request carries a random 128 bit nonce. The device
+   response binds that nonce to chip family, firmware version, current node
+   identity, private server target, configuration state, and a pseudonymous
+   64 bit device digest derived from the base MAC under a RuView domain.
+
+2. A configuration request is accepted only for the most recently issued
+   nonce within 60 seconds. The nonce is single use. Node identity is limited
+   to 1 through 255, the target is limited to RFC 1918 IPv4, and the target port
+   is limited to 1 through 65535.
+
+3. Existing WiFi configuration can be preserved. New credentials use strict
+   base64 framing, bounded lengths, and control character rejection. Firmware
+   commits NVS before acknowledging and rebooting. Credentials are never
+   returned, logged, or included in the receipt.
+
+4. The macOS client uses a native serial bridge. It allowlists exact character
+   device prefixes, configures the port directly, and does not invoke a shell,
+   Python, or an external process. It rechecks the device digest immediately
+   before configuration to reduce port substitution risk.
+
+5. The app suggests the lowest unused server node identity and the Mac private
+   LAN address. Success is shown only after the configured node appears in the
+   server inventory as active with evidence no older than three seconds.
+
+6. Old firmware is reported as requiring an update. The app must not claim it
+   provisioned a device based only on generic RuView serial logs.
+
+7. Automatic firmware flashing is outside this decision. Flashing requires an
+   exact chip and port check, a private backup, a matching image, and captured
+   boot evidence. Release publication remains a separate maintainer action.
+
+## Security and privacy consequences
+
+The app gains Mac App Sandbox USB and serial device access, but not general file
+or shell authority. The protocol does not authenticate a device with a hardware
+root of trust; the digest is stable identification, not a cryptographic device
+certificate. Physical USB possession is therefore the trust boundary for this
+version. An authenticated fleet identity remains ADR 305 scope.
+
+The largest failure mode is a successful NVS write followed by failure to join
+the LAN. The user receives an explicit bounded verification failure instead of
+a success screen, while the board retains its committed settings and can be
+rescanned over USB.
+
+## Acceptance test
+
+Connect an ESP32 with firmware 0.8.9 to a Mac that is already receiving RuView
+nodes. Use only the macOS Add Sensor workflow to preserve WiFi, assign the
+lowest unused identity, and set the Mac private address. Pass when the UI
+reports the expected chip and firmware, the reassigned node remains fresh for
+five minutes, the stale collided identity expires, app restart preserves the
+profile, no server health, send, watchdog, panic, or reboot evidence appears,
+and no credential appears in app logs or the provisioning receipt.
+
+The 2026-08-31 physical run passed on an ESP32 S3. The measured witness is in
+`docs/validation/2026-08-31-macos-usb-node-onboarding.md`.

docs/adr/README.md

@@ -115,6 +115,7 @@ Statuses: **Proposed** (under discussion), **Accepted** (approved and/or impleme
 | [ADR-344](ADR-344-adaptive-local-installation-discovery.md) | Adaptive Local Installation Discovery | Accepted (local software path) |
 | [ADR-346](ADR-346-fail-closed-edge-occupancy-evidence.md) | Fail closed ESP32 occupancy evidence | Accepted (C6 occupancy integrity qualified) |
 | [ADR-347](ADR-347-rate-aware-esp32-temporal-sensing.md) | Rate aware ESP32 temporal sensing | Accepted (C6 timing and transport qualified) |
+| [ADR-348](ADR-348-native-macos-usb-node-onboarding.md) | Native macOS USB node onboarding with nonce bound discovery and fresh server verification | Accepted and physically qualified on one ESP32 S3; C6 and signed distribution pending |
 | [ADR-115](ADR-115-home-assistant-integration.md) | Home Assistant integration via MQTT auto-discovery + Matter bridge (HA-DISCO + HA-FABRIC + HA-MIND) | Accepted (MQTT track) / Proposed (Matter SDK P8b) |
 | [ADR-169](ADR-169-adam-mode-light-theme.md) | adam-mode — light theme toggle for the three.js realtime demo | Proposed |
 | [ADR-170](ADR-170-yoga-mode-pose-system.md) | yoga-mode — yoga pose detection, classification, and scoring for the three.js realtime demo | Proposed |

docs/validation/2026-08-31-macos-usb-node-onboarding.md

@@ -0,0 +1,50 @@
+# Native macOS USB onboarding firmware witness
+
+## Evidence class
+
+MEASURED on 2026-08-31 with one physical ESP32 S3. This is not an ESP32 C6 or
+release distribution qualification.
+
+## Hardware and firmware
+
+The board was identified by the flashing tool as ESP32 S3 QFN56 revision 0.2
+with 2 MB embedded PSRAM and 8 MB flash. Firmware 0.8.9 was built for ESP32 S3
+with the displayless DevKitC defaults. The private configuration region was
+backed up before flashing. The flash operation omitted NVS, preserving the
+existing WiFi configuration.
+
+No base MAC, WiFi credential, device digest, or raw CSI is retained in this
+witness.
+
+## Results
+
+1. The initial native USB scan failed because the ESP-IDF secondary USB
+   Serial/JTAG console mirrors output but does not forward input to STDIN.
+2. Firmware was corrected to read the bounded onboarding protocol from the
+   secondary VFS while retaining STDIN for UART console boards.
+3. A direct nonce challenge then returned ESP32 S3, firmware 0.8.9, configured
+   state, the current node identity, and the private server route.
+4. The Mac app changed the collided identity from 1 to unused identity 5 while
+   preserving WiFi. It showed success only after receiving fresh server
+   evidence at minus 56 dBm.
+5. A five minute monitor collected 299 samples with zero node 5 missing events,
+   zero node 5 stale events, zero server health failures, minus 57 to minus 50
+   dBm RSSI, and 216 ms maximum packet age.
+6. Firmware uptime exceeded 376 seconds. Captured logs advanced from CSI
+   callback 10,600 through 11,000, emitted a node 5 synchronization packet, and
+   showed ESP NOW transmit failures equal to zero without reboot, watchdog, or
+   panic evidence.
+7. The final channel isolation hardening image was flashed and challenged
+   again. A following 60 sample check had zero missing, stale, or health failure
+   events, a maximum packet age of 100 ms, and minus 57 to minus 50 dBm RSSI.
+
+## Software gates
+
+The nonce and configuration parser host test passed, the complete ESP32 S3
+firmware image built under ESP-IDF 5.4, and the application image occupied
+941,056 bytes with 55 percent of the smallest application partition free.
+
+## Remaining gates
+
+Physical ESP32 C6, new WiFi credential entry, signed Mac distribution, and
+cross platform serial bridges remain unmeasured.

firmware/esp32-csi-node/README.md

@@ -19,6 +19,21 @@ This firmware captures WiFi Channel State Information (CSI) from an ESP32-S3 (pr
 > | **Fall detection** | Phase acceleration threshold | Configurable sensitivity |
 > | **Programmable sensing** | WASM modules loaded over HTTP | Hot-swap, no reflash |
 
+## Development firmware 0.8.9: guided Mac onboarding
+
+The unreleased 0.8.9 source adds the protocol used by the RuView macOS Add
+Sensor workflow. A directly attached S3 or C6 can identify itself through a
+nonce bound USB serial receipt, preserve its current WiFi settings, accept an
+unused node ID and private LAN server address, then reboot. The Mac app does
+not report success until the sensing server observes that node as fresh.
+
+This is not a firmware flashing API. A board on 0.8.8 or earlier must receive a
+matching chip build through the documented backup and flash process once. The
+USB protocol rejects public target addresses and invalid identifiers. New WiFi
+credentials are bounded, committed only in NVS, and never included in the
+receipt or diagnostic output. See
+[ADR 348](../../docs/adr/ADR-348-native-macos-usb-node-onboarding.md).
+
 ## Firmware 0.8.8 in plain language
 
 Release 0.8.8 makes the sensing stream more internally consistent and easier

firmware/esp32-csi-node/main/CMakeLists.txt

@@ -1,6 +1,7 @@
 set(SRCS
     "main.c" "csi_collector.c"
     "thermal.c" "stream_sender.c" "nvs_config.c"
+    "serial_onboarding.c" "serial_onboarding_protocol.c"
     "edge_processing.c" "ota_update.c" "power_mgmt.c"
     "wasm_runtime.c" "wasm_upload.c" "rvf_parser.c"
     "mmwave_sensor.c"
@@ -40,6 +41,7 @@ set(REQUIRES
     driver
     lwip
     mbedtls
+    efuse
 )
 
 # ADR-110: C6-only components — pulled in when building for esp32c6.

firmware/esp32-csi-node/main/main.c

@@ -24,6 +24,7 @@
 #include "thermal.h"
 #include "stream_sender.h"
 #include "nvs_config.h"
+#include "serial_onboarding.h"
 #include "edge_processing.h"
 #include "ota_update.h"
 #include "power_mgmt.h"
@@ -336,6 +337,14 @@ void app_main(void)
      * ownership of GPIO3 and GPIO14 because the default implementation is a
      * no-op unless CONFIG_C6_XIAO_ANTENNA_SELECT is enabled. */
     ESP_ERROR_CHECK(c6_xiao_antenna_apply());
+    /* The native Mac onboarding bridge must remain available even when WiFi
+     * credentials or the aggregator address are wrong. Start it before any
+     * blocking network initialization. The protocol is physical-USB-only,
+     * nonce-bound, bounded, and never prints credentials. */
+    esp_err_t onboarding_ret = serial_onboarding_start(&g_nvs_config);
+    if (onboarding_ret != ESP_OK) {
+        ESP_LOGW(TAG, "USB onboarding unavailable: %s", esp_err_to_name(onboarding_ret));
+    }
 
     /* Onboard WS2812. C6 wires the LED to GPIO 8; S3 to GPIO 38 (DevKitC-1 v1.0)
      * or GPIO 48 (DevKitC-1 v1.1 / N16R8 — see #962). On S3 we drive 48 (the

firmware/esp32-csi-node/main/nvs_config.c

@@ -109,7 +109,7 @@ void nvs_config_load(nvs_config_t *cfg)
     len = sizeof(buf);
     if (nvs_get_str(handle, "ssid", buf, &len) == ESP_OK && len > 1) {
         strlcpy(cfg->wifi_ssid, buf, sizeof(cfg->wifi_ssid));
-        ESP_LOGI(TAG, "NVS override: ssid=%s", cfg->wifi_ssid);
+        ESP_LOGI(TAG, "NVS override: ssid=<configured>");
     }
 
     /* WiFi password */

firmware/esp32-csi-node/main/serial_onboarding.c

@@ -0,0 +1,200 @@
+#include "serial_onboarding.h"
+
+#include "serial_onboarding_protocol.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "esp_app_desc.h"
+#include "esp_efuse.h"
+#include "esp_log.h"
+#include "esp_mac.h"
+#include "esp_system.h"
+#include "esp_timer.h"
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+#include "mbedtls/sha256.h"
+#include "nvs.h"
+
+static const char *TAG = "serial_onboard";
+static nvs_config_t s_current_config;
+static char s_issued_nonce[RUVIEW_ONBOARDING_NONCE_HEX_LEN + 1];
+static int64_t s_nonce_issued_at_us;
+
+#define ONBOARDING_LINE_MAX 384
+#define ONBOARDING_NONCE_TTL_US (60LL * 1000LL * 1000LL)
+
+static const char *chip_name(void)
+{
+#if defined(CONFIG_IDF_TARGET_ESP32C6)
+    return "esp32c6";
+#elif defined(CONFIG_IDF_TARGET_ESP32S3)
+    return "esp32s3";
+#else
+    return "esp32";
+#endif
+}
+
+static void device_digest(char output[17])
+{
+    uint8_t base_mac[6] = {0};
+    uint8_t digest[32] = {0};
+    static const uint8_t domain[] = "ruview-device-v1";
+    mbedtls_sha256_context context;
+    mbedtls_sha256_init(&context);
+    if (esp_efuse_mac_get_default(base_mac) == ESP_OK &&
+        mbedtls_sha256_starts(&context, 0) == 0 &&
+        mbedtls_sha256_update(&context, domain, sizeof(domain) - 1) == 0 &&
+        mbedtls_sha256_update(&context, base_mac, sizeof(base_mac)) == 0 &&
+        mbedtls_sha256_finish(&context, digest) == 0) {
+        for (size_t index = 0; index < 8; index++) {
+            snprintf(output + index * 2, 3, "%02x", digest[index]);
+        }
+    } else {
+        memcpy(output, "0000000000000000", 17);
+    }
+    mbedtls_sha256_free(&context);
+}
+
+static void emit_hello(const char *nonce)
+{
+    const esp_app_desc_t *description = esp_app_get_description();
+    char digest[17] = {0};
+    device_digest(digest);
+    const bool configured = s_current_config.wifi_ssid[0] != '\0' &&
+                            s_current_config.target_ip[0] != '\0';
+    printf("RUVIEW_HELLO_OK_V1 nonce=%s chip=%s version=%s node_id=%u "
+           "target_ip=%s target_port=%u configured=%u device_digest=%s\n",
+           nonce, chip_name(), description->version,
+           (unsigned)s_current_config.node_id, s_current_config.target_ip,
+           (unsigned)s_current_config.target_port, configured ? 1U : 0U, digest);
+    fflush(stdout);
+}
+
+static esp_err_t commit_config(const ruview_onboarding_config_t *config)
+{
+    nvs_handle_t handle;
+    esp_err_t result = nvs_open("csi_cfg", NVS_READWRITE, &handle);
+    if (result != ESP_OK) return result;
+    if (!config->preserve_wifi) {
+        result = nvs_set_str(handle, "ssid", config->ssid);
+        if (result == ESP_OK) result = nvs_set_str(handle, "password", config->password);
+    }
+    if (result == ESP_OK) result = nvs_set_str(handle, "target_ip", config->target_ip);
+    if (result == ESP_OK) result = nvs_set_u16(handle, "target_port", config->target_port);
+    if (result == ESP_OK) result = nvs_set_u8(handle, "node_id", config->node_id);
+    if (result == ESP_OK) result = nvs_commit(handle);
+    nvs_close(handle);
+    return result;
+}
+
+static void process_line(char *line)
+{
+    char nonce[RUVIEW_ONBOARDING_NONCE_HEX_LEN + 1] = {0};
+    if (ruview_onboarding_parse_hello(line, nonce)) {
+        memcpy(s_issued_nonce, nonce, sizeof(s_issued_nonce));
+        s_nonce_issued_at_us = esp_timer_get_time();
+        emit_hello(nonce);
+        return;
+    }
+    if (strncmp(line, "RUVIEW_CONFIG_V1 ", 17) != 0) return;
+
+    ruview_onboarding_config_t request;
+    const ruview_onboarding_result_t parsed = ruview_onboarding_parse_config(line, &request);
+    if (parsed != RUVIEW_ONBOARDING_OK) {
+        printf("RUVIEW_CONFIG_ERR_V1 reason=%s\n", ruview_onboarding_result_name(parsed));
+        fflush(stdout);
+        return;
+    }
+    const int64_t age_us = esp_timer_get_time() - s_nonce_issued_at_us;
+    if (s_issued_nonce[0] == '\0' || strcmp(request.nonce, s_issued_nonce) != 0 ||
+        age_us < 0 || age_us > ONBOARDING_NONCE_TTL_US) {
+        printf("RUVIEW_CONFIG_ERR_V1 nonce=%s reason=claim_expired\n", request.nonce);
+        fflush(stdout);
+        return;
+    }
+    s_issued_nonce[0] = '\0';
+    const esp_err_t result = commit_config(&request);
+    if (result != ESP_OK) {
+        printf("RUVIEW_CONFIG_ERR_V1 nonce=%s reason=nvs_commit code=%s\n",
+               request.nonce, esp_err_to_name(result));
+        fflush(stdout);
+        return;
+    }
+
+    printf("RUVIEW_CONFIG_OK_V1 nonce=%s node_id=%u rebooting=1\n",
+           request.nonce, (unsigned)request.node_id);
+    fflush(stdout);
+    vTaskDelay(pdMS_TO_TICKS(400));
+    esp_restart();
+}
+
+static void consume_bytes(const uint8_t *input, ssize_t count, char *line,
+                          size_t *length, bool *overflow)
+{
+    for (ssize_t index = 0; index < count; index++) {
+        const uint8_t byte = input[index];
+        if (byte == '\r') continue;
+        if (byte == '\n') {
+            if (!*overflow && *length > 0) {
+                line[*length] = '\0';
+                process_line(line);
+            }
+            *length = 0;
+            *overflow = false;
+            continue;
+        }
+        if (byte < 0x20 || byte == 0x7f) continue;
+        if (*length + 1 < ONBOARDING_LINE_MAX) line[(*length)++] = (char)byte;
+        else *overflow = true;
+    }
+}
+
+static void serial_onboarding_task(void *argument)
+{
+    (void)argument;
+    const int original_flags = fcntl(STDIN_FILENO, F_GETFL, 0);
+    if (original_flags >= 0) (void)fcntl(STDIN_FILENO, F_SETFL, original_flags | O_NONBLOCK);
+    /* ESP-IDF secondary consoles mirror output but deliberately do not forward
+     * input to STDIN. Native S3/C6 USB Serial/JTAG therefore needs a bounded
+     * direct VFS reader while UART-console boards continue to use STDIN. */
+    const int usb_fd = open("/dev/secondary", O_RDONLY | O_NONBLOCK);
+    char primary_line[ONBOARDING_LINE_MAX];
+    char usb_line[ONBOARDING_LINE_MAX];
+    size_t primary_length = 0;
+    size_t usb_length = 0;
+    bool primary_overflow = false;
+    bool usb_overflow = false;
+    for (;;) {
+        uint8_t input[64];
+        const ssize_t count = read(STDIN_FILENO, input, sizeof(input));
+        if (count > 0) {
+            consume_bytes(input, count, primary_line, &primary_length, &primary_overflow);
+        }
+        else if (count < 0 && errno != EAGAIN && errno != EWOULDBLOCK) {
+            ESP_LOGW(TAG, "serial input unavailable: errno=%d", errno);
+            vTaskDelay(pdMS_TO_TICKS(500));
+        }
+        if (usb_fd >= 0) {
+            const ssize_t usb_count = read(usb_fd, input, sizeof(input));
+            if (usb_count > 0) {
+                consume_bytes(input, usb_count, usb_line, &usb_length, &usb_overflow);
+            }
+        }
+        vTaskDelay(pdMS_TO_TICKS(20));
+    }
+}
+
+esp_err_t serial_onboarding_start(const nvs_config_t *config)
+{
+    if (config == NULL) return ESP_ERR_INVALID_ARG;
+    memcpy(&s_current_config, config, sizeof(s_current_config));
+    const BaseType_t created = xTaskCreate(serial_onboarding_task, "serial_onboard",
+                                           4096, NULL, 4, NULL);
+    if (created != pdPASS) return ESP_ERR_NO_MEM;
+    ESP_LOGI(TAG, "bounded serial onboarding ready");
+    return ESP_OK;
+}

firmware/esp32-csi-node/main/serial_onboarding.h

@@ -0,0 +1,15 @@
+#ifndef SERIAL_ONBOARDING_H
+#define SERIAL_ONBOARDING_H
+
+#include "esp_err.h"
+#include "nvs_config.h"
+
+/** Start the bounded USB serial onboarding listener.
+ *
+ * The listener exposes device metadata and accepts one nonce-bound
+ * configuration transaction. It never prints WiFi credentials and reboots
+ * only after a successful atomic NVS commit.
+ */
+esp_err_t serial_onboarding_start(const nvs_config_t *config);
+
+#endif

firmware/esp32-csi-node/main/serial_onboarding_protocol.c

@@ -0,0 +1,214 @@
+#ifndef _POSIX_C_SOURCE
+#define _POSIX_C_SOURCE 200809L /* strtok_r under -std=c11 -pedantic on glibc */
+#endif
+#include "serial_onboarding_protocol.h"
+
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define HELLO_COMMAND "RUVIEW_HELLO_V1"
+#define CONFIG_COMMAND "RUVIEW_CONFIG_V1"
+
+static bool valid_nonce(const char *value)
+{
+    if (value == NULL || strlen(value) != RUVIEW_ONBOARDING_NONCE_HEX_LEN) return false;
+    for (size_t index = 0; index < RUVIEW_ONBOARDING_NONCE_HEX_LEN; index++) {
+        const char c = value[index];
+        if (!((c >= '0' && c <= '9') || (c >= 'a' && c <= 'f') ||
+              (c >= 'A' && c <= 'F'))) return false;
+    }
+    return true;
+}
+
+static bool parse_u32(const char *value, uint32_t maximum, uint32_t *output)
+{
+    if (value == NULL || value[0] == '\0' || output == NULL) return false;
+    uint32_t result = 0;
+    for (const char *cursor = value; *cursor != '\0'; cursor++) {
+        if (*cursor < '0' || *cursor > '9') return false;
+        const uint32_t digit = (uint32_t)(*cursor - '0');
+        if (result > (maximum - digit) / 10U) return false;
+        result = result * 10U + digit;
+    }
+    *output = result;
+    return true;
+}
+
+static bool valid_ipv4(const char *value)
+{
+    if (value == NULL || value[0] == '\0' || strlen(value) > 15) return false;
+    unsigned octets = 0;
+    const char *cursor = value;
+    while (*cursor != '\0') {
+        if (octets == 4) return false;
+        if (*cursor == '.') return false;
+        uint32_t octet = 0;
+        unsigned digits = 0;
+        while (*cursor != '\0' && *cursor != '.') {
+            if (*cursor < '0' || *cursor > '9' || digits == 3) return false;
+            octet = octet * 10U + (uint32_t)(*cursor - '0');
+            if (octet > 255U) return false;
+            digits++;
+            cursor++;
+        }
+        if (digits == 0) return false;
+        octets++;
+        if (*cursor == '.') cursor++;
+    }
+    return octets == 4;
+}
+
+static bool valid_private_ipv4(const char *value)
+{
+    if (!valid_ipv4(value)) return false;
+    unsigned first = 0;
+    unsigned second = 0;
+    if (sscanf(value, "%u.%u", &first, &second) != 2) return false;
+    return first == 10U || (first == 172U && second >= 16U && second <= 31U) ||
+           (first == 192U && second == 168U);
+}
+
+static int base64_value(char c)
+{
+    if (c >= 'A' && c <= 'Z') return c - 'A';
+    if (c >= 'a' && c <= 'z') return c - 'a' + 26;
+    if (c >= '0' && c <= '9') return c - '0' + 52;
+    if (c == '+') return 62;
+    if (c == '/') return 63;
+    return -1;
+}
+
+static bool decode_base64(const char *encoded, uint8_t *output,
+                          size_t output_capacity, size_t *output_length)
+{
+    if (encoded == NULL || output == NULL || output_length == NULL) return false;
+    const size_t length = strlen(encoded);
+    if (length == 0 || length % 4 != 0) return false;
+    size_t written = 0;
+    for (size_t index = 0; index < length; index += 4) {
+        int values[4];
+        unsigned padding = 0;
+        for (unsigned offset = 0; offset < 4; offset++) {
+            const char c = encoded[index + offset];
+            if (c == '=') {
+                if (offset < 2 || index + 4 != length) return false;
+                values[offset] = 0;
+                padding++;
+            } else {
+                if (padding != 0) return false;
+                values[offset] = base64_value(c);
+                if (values[offset] < 0) return false;
+            }
+        }
+        if (padding > 2) return false;
+        const uint32_t block = ((uint32_t)values[0] << 18) |
+                               ((uint32_t)values[1] << 12) |
+                               ((uint32_t)values[2] << 6) |
+                               (uint32_t)values[3];
+        const unsigned bytes = 3U - padding;
+        if (written + bytes > output_capacity) return false;
+        output[written++] = (uint8_t)(block >> 16);
+        if (bytes > 1) output[written++] = (uint8_t)(block >> 8);
+        if (bytes > 2) output[written++] = (uint8_t)block;
+    }
+    *output_length = written;
+    return true;
+}
+
+static bool printable_secret(const uint8_t *bytes, size_t length)
+{
+    if (bytes == NULL) return false;
+    for (size_t index = 0; index < length; index++) {
+        if (bytes[index] < 0x20 || bytes[index] == 0x7f) return false;
+    }
+    return true;
+}
+
+int ruview_onboarding_parse_hello(
+    const char *line,
+    char nonce[RUVIEW_ONBOARDING_NONCE_HEX_LEN + 1])
+{
+    if (line == NULL || nonce == NULL) return 0;
+    const size_t prefix_length = strlen(HELLO_COMMAND);
+    if (strncmp(line, HELLO_COMMAND, prefix_length) != 0 || line[prefix_length] != ' ')
+        return 0;
+    const char *candidate = line + prefix_length + 1;
+    if (!valid_nonce(candidate)) return 0;
+    memcpy(nonce, candidate, RUVIEW_ONBOARDING_NONCE_HEX_LEN + 1);
+    return 1;
+}
+
+ruview_onboarding_result_t ruview_onboarding_parse_config(
+    const char *line,
+    ruview_onboarding_config_t *config)
+{
+    if (line == NULL || config == NULL || strlen(line) >= 384) return RUVIEW_ONBOARDING_ERR_FORMAT;
+    char copy[384];
+    memcpy(copy, line, strlen(line) + 1);
+
+    char *tokens[7] = {0};
+    size_t token_count = 0;
+    char *save = NULL;
+    for (char *token = strtok_r(copy, " ", &save); token != NULL;
+         token = strtok_r(NULL, " ", &save)) {
+        if (token_count == 7) return RUVIEW_ONBOARDING_ERR_FORMAT;
+        tokens[token_count++] = token;
+    }
+    if (token_count != 7 || strcmp(tokens[0], CONFIG_COMMAND) != 0)
+        return RUVIEW_ONBOARDING_ERR_FORMAT;
+    if (!valid_nonce(tokens[1])) return RUVIEW_ONBOARDING_ERR_NONCE;
+
+    uint32_t node_id = 0;
+    if (!parse_u32(tokens[2], 255, &node_id) || node_id == 0)
+        return RUVIEW_ONBOARDING_ERR_NODE_ID;
+    if (!valid_private_ipv4(tokens[3])) return RUVIEW_ONBOARDING_ERR_TARGET_IP;
+    uint32_t target_port = 0;
+    if (!parse_u32(tokens[4], 65535, &target_port) || target_port == 0)
+        return RUVIEW_ONBOARDING_ERR_TARGET_PORT;
+
+    const bool preserve_wifi = strcmp(tokens[5], "KEEP") == 0 &&
+                               strcmp(tokens[6], "KEEP") == 0;
+    if ((strcmp(tokens[5], "KEEP") == 0) != (strcmp(tokens[6], "KEEP") == 0))
+        return RUVIEW_ONBOARDING_ERR_FORMAT;
+    uint8_t ssid[RUVIEW_ONBOARDING_SSID_MAX_BYTES];
+    size_t ssid_length = 0;
+    if (!preserve_wifi && (!decode_base64(tokens[5], ssid, sizeof(ssid), &ssid_length) ||
+        ssid_length == 0 || !printable_secret(ssid, ssid_length)))
+        return RUVIEW_ONBOARDING_ERR_SSID;
+    uint8_t password[RUVIEW_ONBOARDING_PASSWORD_MAX_BYTES];
+    size_t password_length = 0;
+    if (!preserve_wifi && (!decode_base64(tokens[6], password, sizeof(password), &password_length) ||
+        password_length < 8 || !printable_secret(password, password_length)))
+        return RUVIEW_ONBOARDING_ERR_PASSWORD;
+
+    memset(config, 0, sizeof(*config));
+    memcpy(config->nonce, tokens[1], RUVIEW_ONBOARDING_NONCE_HEX_LEN + 1);
+    config->node_id = (uint8_t)node_id;
+    memcpy(config->target_ip, tokens[3], strlen(tokens[3]) + 1);
+    config->target_port = (uint16_t)target_port;
+    config->preserve_wifi = preserve_wifi;
+    if (!preserve_wifi) {
+        memcpy(config->ssid, ssid, ssid_length);
+        config->ssid[ssid_length] = '\0';
+        memcpy(config->password, password, password_length);
+        config->password[password_length] = '\0';
+    }
+    return RUVIEW_ONBOARDING_OK;
+}
+
+const char *ruview_onboarding_result_name(ruview_onboarding_result_t result)
+{
+    switch (result) {
+    case RUVIEW_ONBOARDING_OK: return "ok";
+    case RUVIEW_ONBOARDING_ERR_FORMAT: return "format";
+    case RUVIEW_ONBOARDING_ERR_NONCE: return "nonce";
+    case RUVIEW_ONBOARDING_ERR_NODE_ID: return "node_id";
+    case RUVIEW_ONBOARDING_ERR_TARGET_IP: return "target_ip";
+    case RUVIEW_ONBOARDING_ERR_TARGET_PORT: return "target_port";
+    case RUVIEW_ONBOARDING_ERR_SSID: return "ssid";
+    case RUVIEW_ONBOARDING_ERR_PASSWORD: return "password";
+    default: return "unknown";
+    }
+}

firmware/esp32-csi-node/main/serial_onboarding_protocol.h

@@ -0,0 +1,42 @@
+#ifndef SERIAL_ONBOARDING_PROTOCOL_H
+#define SERIAL_ONBOARDING_PROTOCOL_H
+
+#include <stddef.h>
+#include <stdbool.h>
+#include <stdint.h>
+
+#define RUVIEW_ONBOARDING_NONCE_HEX_LEN 32
+#define RUVIEW_ONBOARDING_SSID_MAX_BYTES 32
+#define RUVIEW_ONBOARDING_PASSWORD_MAX_BYTES 63
+
+typedef struct {
+    char nonce[RUVIEW_ONBOARDING_NONCE_HEX_LEN + 1];
+    uint8_t node_id;
+    char target_ip[16];
+    uint16_t target_port;
+    bool preserve_wifi;
+    char ssid[RUVIEW_ONBOARDING_SSID_MAX_BYTES + 1];
+    char password[RUVIEW_ONBOARDING_PASSWORD_MAX_BYTES + 1];
+} ruview_onboarding_config_t;
+
+typedef enum {
+    RUVIEW_ONBOARDING_OK = 0,
+    RUVIEW_ONBOARDING_ERR_FORMAT,
+    RUVIEW_ONBOARDING_ERR_NONCE,
+    RUVIEW_ONBOARDING_ERR_NODE_ID,
+    RUVIEW_ONBOARDING_ERR_TARGET_IP,
+    RUVIEW_ONBOARDING_ERR_TARGET_PORT,
+    RUVIEW_ONBOARDING_ERR_SSID,
+    RUVIEW_ONBOARDING_ERR_PASSWORD,
+} ruview_onboarding_result_t;
+
+int ruview_onboarding_parse_hello(const char *line,
+                                  char nonce[RUVIEW_ONBOARDING_NONCE_HEX_LEN + 1]);
+
+ruview_onboarding_result_t ruview_onboarding_parse_config(
+    const char *line,
+    ruview_onboarding_config_t *config);
+
+const char *ruview_onboarding_result_name(ruview_onboarding_result_t result);
+
+#endif

firmware/esp32-csi-node/test/Makefile

@@ -55,10 +55,10 @@ FUZZ_JOBS     ?= 1
 .PHONY: all clean run_serialize run_edge run_nvs run_all test_adr110 run_adr110 \
         test_vitals run_vitals test_mmwave_detect run_mmwave_detect host_tests \
         test_thermal run_thermal test_csi_sanitize run_csi_sanitize \
-        test_c6_antenna run_c6_antenna
+        test_c6_antenna run_c6_antenna test_serial_onboarding run_serial_onboarding
 
 all: fuzz_serialize fuzz_edge fuzz_nvs test_adr110 test_vitals test_mmwave_detect \
-     test_thermal test_csi_sanitize test_c6_antenna
+     test_thermal test_csi_sanitize test_c6_antenna test_serial_onboarding
 
 # --- XIAO ESP32-C6 RF switch selection ---
 # Host-side truth table for the GPIO14 antenna selector. GPIO3 is always driven
@@ -122,9 +122,19 @@ test_thermal: test_thermal_hysteresis.c $(MAIN_DIR)/thermal.h
 run_thermal: test_thermal
 	./test_thermal
 
+# --- Native Mac USB onboarding protocol ---
+# Tests the production parser and secret validation without ESP-IDF. This pins
+# nonce shape, IPv4 and node bounds, base64 handling, and control-byte denial.
+test_serial_onboarding: test_serial_onboarding_protocol.c $(MAIN_DIR)/serial_onboarding_protocol.c $(MAIN_DIR)/serial_onboarding_protocol.h
+	cc -std=c11 -Wall -Wextra -Werror -pedantic -I$(MAIN_DIR) -o $@ \
+		test_serial_onboarding_protocol.c $(MAIN_DIR)/serial_onboarding_protocol.c
+
+run_serial_onboarding: test_serial_onboarding
+	./test_serial_onboarding
+
 host_tests: run_adr110 run_vitals run_mmwave_detect run_thermal run_csi_sanitize \
-            run_c6_antenna
+            run_c6_antenna run_serial_onboarding
-	@echo "Host tests passed (ADR-110 + CSI sanitation + vitals + mmwave + thermal + C6 antenna)"
+	@echo "Host tests passed (ADR-110 + CSI sanitation + vitals + mmwave + thermal + C6 antenna + USB onboarding)"
 
 # --- Serialize fuzzer ---
 # Tests csi_serialize_frame() with random wifi_csi_info_t inputs.
@@ -161,5 +171,5 @@ run_all: run_serialize run_edge run_nvs
 
 clean:
 	rm -f fuzz_serialize fuzz_edge fuzz_nvs test_adr110 test_vitals test_mmwave_detect \
-		test_thermal test_csi_sanitize test_c6_antenna
+		test_thermal test_csi_sanitize test_c6_antenna test_serial_onboarding
 	rm -rf corpus_serialize/ corpus_edge/ corpus_nvs/

firmware/esp32-csi-node/test/test_serial_onboarding_protocol.c

@@ -0,0 +1,68 @@
+#include <assert.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "../main/serial_onboarding_protocol.h"
+
+static void test_hello(void)
+{
+    char nonce[33] = {0};
+    assert(ruview_onboarding_parse_hello(
+        "RUVIEW_HELLO_V1 00112233445566778899aabbccddeeff", nonce));
+    assert(strcmp(nonce, "00112233445566778899aabbccddeeff") == 0);
+    assert(!ruview_onboarding_parse_hello("RUVIEW_HELLO_V1 bad", nonce));
+    assert(!ruview_onboarding_parse_hello(
+        "RUVIEW_HELLO_V1 00112233445566778899aabbccddeeff extra", nonce));
+}
+
+static void test_config(void)
+{
+    ruview_onboarding_config_t config;
+    assert(ruview_onboarding_parse_config(
+        "RUVIEW_CONFIG_V1 00112233445566778899aabbccddeeff 5 192.168.1.166 5005 "
+        "UnVWaWV3IExhYg== U3Ryb25nUGFzc3dvcmQ=", &config) == RUVIEW_ONBOARDING_OK);
+    assert(config.node_id == 5);
+    assert(config.target_port == 5005);
+    assert(strcmp(config.target_ip, "192.168.1.166") == 0);
+    assert(strcmp(config.ssid, "RuView Lab") == 0);
+    assert(strcmp(config.password, "StrongPassword") == 0);
+    assert(!config.preserve_wifi);
+    assert(ruview_onboarding_parse_config(
+        "RUVIEW_CONFIG_V1 00112233445566778899aabbccddeeff 6 192.168.1.166 5005 KEEP KEEP",
+        &config) == RUVIEW_ONBOARDING_OK);
+    assert(config.preserve_wifi);
+}
+
+static void test_rejections(void)
+{
+    ruview_onboarding_config_t config;
+    const char *prefix = "RUVIEW_CONFIG_V1 00112233445566778899aabbccddeeff";
+    char line[512];
+    snprintf(line, sizeof(line), "%s 0 192.168.1.2 5005 UnVWaWV3 U3Ryb25nUGFzc3dvcmQ=", prefix);
+    assert(ruview_onboarding_parse_config(line, &config) == RUVIEW_ONBOARDING_ERR_NODE_ID);
+    snprintf(line, sizeof(line), "%s 5 999.1.1.1 5005 UnVWaWV3 U3Ryb25nUGFzc3dvcmQ=", prefix);
+    assert(ruview_onboarding_parse_config(line, &config) == RUVIEW_ONBOARDING_ERR_TARGET_IP);
+    snprintf(line, sizeof(line), "%s 5 8.8.8.8 5005 UnVWaWV3 U3Ryb25nUGFzc3dvcmQ=", prefix);
+    assert(ruview_onboarding_parse_config(line, &config) == RUVIEW_ONBOARDING_ERR_TARGET_IP);
+    snprintf(line, sizeof(line), "%s 5 172.32.0.1 5005 UnVWaWV3 U3Ryb25nUGFzc3dvcmQ=", prefix);
+    assert(ruview_onboarding_parse_config(line, &config) == RUVIEW_ONBOARDING_ERR_TARGET_IP);
+    snprintf(line, sizeof(line), "%s 5 192.168.1.2 0 UnVWaWV3 U3Ryb25nUGFzc3dvcmQ=", prefix);
+    assert(ruview_onboarding_parse_config(line, &config) == RUVIEW_ONBOARDING_ERR_TARGET_PORT);
+    snprintf(line, sizeof(line), "%s 5 192.168.1.2 5005 !!!! U3Ryb25nUGFzc3dvcmQ=", prefix);
+    assert(ruview_onboarding_parse_config(line, &config) == RUVIEW_ONBOARDING_ERR_SSID);
+    snprintf(line, sizeof(line), "%s 5 192.168.1.2 5005 UnVWaWV3 c2hvcnQ=", prefix);
+    assert(ruview_onboarding_parse_config(line, &config) == RUVIEW_ONBOARDING_ERR_PASSWORD);
+    snprintf(line, sizeof(line), "%s 5 192.168.1.2 5005 UnVWaWV3 UGFzc3dvcmQxCg==", prefix);
+    assert(ruview_onboarding_parse_config(line, &config) == RUVIEW_ONBOARDING_ERR_PASSWORD);
+    snprintf(line, sizeof(line), "%s 5 192.168.1.2 5005 KEEP U3Ryb25nUGFzc3dvcmQ=", prefix);
+    assert(ruview_onboarding_parse_config(line, &config) == RUVIEW_ONBOARDING_ERR_FORMAT);
+}
+
+int main(void)
+{
+    test_hello();
+    test_config();
+    test_rejections();
+    puts("serial onboarding protocol tests passed");
+    return 0;
+}

firmware/esp32-csi-node/version.txt

@@ -1 +1 @@
-0.8.10
+0.8.11