feat: OTA-Trailer bauen und prüfen

2026-09-12 01:16:04 +02:00
parent c96e0442c0
commit e3be3e84c1
5 changed files with 199 additions and 0 deletions
@@ -52,6 +52,7 @@ set(NL_FW_SOURCES
  src/app_main.c
  src/util/nl_sha256.c
  src/util/nl_crc.c
+  src/util/nl_fwup_trailer.c
  src/board/nl_board.c
  src/light/nl_color.c
  src/light/nl_engine.c
@@ -0,0 +1,74 @@
+#include "util/nl_fwup_trailer.h"
+
+#include <string.h>
+
+/* NB: This layout is mirrored in Python at tools/mkimage/nl_mkimage.py (Task 3),
+   since there are two languages involved. Keep both in sync. */
+
+#define OFF_MAGIC   0u
+#define OFF_VERSION 4u
+#define OFF_DEVICE  5u
+#define OFF_FW      21u
+#define OFF_SHA     37u
+
+static bool copy_field(uint8_t *dst, const char *src, uint32_t len)
+{
+    uint32_t n = (uint32_t)strlen(src);
+    if (n >= len)
+        return false;
+    memset(dst, 0, len);
+    memcpy(dst, src, n);
+    return true;
+}
+
+bool nl_trailer_build(uint8_t out[NL_TRAILER_SIZE], const char *device, const char *version, const uint8_t sha256[32])
+{
+    memset(out, 0xFF, NL_TRAILER_SIZE);
+    memcpy(&out[OFF_MAGIC], "NINL", 4);
+    out[OFF_VERSION] = NL_TRAILER_VERSION;
+    if (!copy_field(&out[OFF_DEVICE], device, NL_TRAILER_DEVICE_LEN) ||
+        !copy_field(&out[OFF_FW], version, NL_TRAILER_VERSION_LEN))
+        return false;
+    memcpy(&out[OFF_SHA], sha256, 32);
+    return true;
+}
+
+static bool terminated(const uint8_t *field, uint32_t len)
+{
+    for (uint32_t i = 0; i < len; i++)
+        if (field[i] == 0)
+            return true;
+    return false;
+}
+
+nl_trailer_err_t nl_trailer_verify(const uint8_t *tail, uint32_t tail_len, const char *device, const uint8_t sha256[32])
+{
+    if (tail == NULL || tail_len < NL_TRAILER_SIZE)
+        return NL_TRAILER_ERR_SIZE;
+    if (memcmp(&tail[OFF_MAGIC], "NINL", 4) != 0)
+        return NL_TRAILER_ERR_MAGIC;
+    if (tail[OFF_VERSION] != NL_TRAILER_VERSION)
+        return NL_TRAILER_ERR_VERSION;
+    if (!terminated(&tail[OFF_DEVICE], NL_TRAILER_DEVICE_LEN) ||
+        strcmp((const char *)&tail[OFF_DEVICE], device) != 0)
+        return NL_TRAILER_ERR_DEVICE;
+    if (memcmp(&tail[OFF_SHA], sha256, 32) != 0)
+        return NL_TRAILER_ERR_HASH;
+    return NL_TRAILER_OK;
+}
+
+void nl_trailer_version(const uint8_t *tail, char *dst)
+{
+    memcpy(dst, &tail[OFF_FW], NL_TRAILER_VERSION_LEN);
+    dst[NL_TRAILER_VERSION_LEN - 1] = '\0';
+}
+
+const char *nl_trailer_err_name(nl_trailer_err_t e)
+{
+    switch (e) {
+    case NL_TRAILER_ERR_DEVICE: return "device_mismatch";
+    case NL_TRAILER_ERR_HASH: return "hash";
+    case NL_TRAILER_OK: return NULL;
+    default: return "trailer";
+    }
+}
@@ -0,0 +1,28 @@
+#ifndef NL_FWUP_TRAILER_H
+#define NL_FWUP_TRAILER_H
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#define NL_TRAILER_SIZE        512u
+#define NL_TRAILER_VERSION     1u
+#define NL_TRAILER_DEVICE_LEN  16u
+#define NL_TRAILER_VERSION_LEN 16u
+
+typedef enum {
+    NL_TRAILER_OK = 0,
+    NL_TRAILER_ERR_SIZE,
+    NL_TRAILER_ERR_MAGIC,
+    NL_TRAILER_ERR_VERSION,
+    NL_TRAILER_ERR_DEVICE,
+    NL_TRAILER_ERR_HASH
+} nl_trailer_err_t;
+
+/* "NINL" | version | device[16] | fw_version[16] | sha256[32] | 0xFF padding */
+bool nl_trailer_build(uint8_t out[NL_TRAILER_SIZE], const char *device, const char *version, const uint8_t sha256[32]);
+nl_trailer_err_t nl_trailer_verify(const uint8_t *tail, uint32_t tail_len, const char *device, const uint8_t sha256[32]);
+void nl_trailer_version(const uint8_t *tail, char *dst); /* dst: NL_TRAILER_VERSION_LEN bytes */
+/* Maps to the last_ota_error vocabulary; NULL for NL_TRAILER_OK. */
+const char *nl_trailer_err_name(nl_trailer_err_t e);
+
+#endif
@@ -48,3 +48,4 @@ nl_test(test_api test_api.c fake_api_ctx.c ${NL_SRC}/net/nl_api.c ${NL_SRC}/boar
        ${NL_SRC}/light/nl_boot_state.c ${NL_SRC}/config/nl_settings.c ${NL_SRC}/util/nl_crc.c fake_flash.c)
 target_link_libraries(test_api PRIVATE nl_cjson)
 nl_test(test_wifi_sm test_wifi_sm.c ${NL_SRC}/net/nl_wifi_sm.c)
+nl_test(test_fwup_trailer test_fwup_trailer.c ${NL_SRC}/util/nl_fwup_trailer.c)
@@ -0,0 +1,95 @@
+#include <string.h>
+#include "unity.h"
+#include "util/nl_fwup_trailer.h"
+
+void setUp(void) {}
+void tearDown(void) {}
+
+static uint8_t HASH[32];
+static uint8_t tail[NL_TRAILER_SIZE];
+
+static void fill_hash(void)
+{
+    for (int i = 0; i < 32; i++)
+        HASH[i] = (uint8_t)(i * 3 + 1);
+}
+
+static void test_build_layout(void)
+{
+    fill_hash();
+    TEST_ASSERT_TRUE(nl_trailer_build(tail, "e27_rgb", "1.2.3", HASH));
+    TEST_ASSERT_EQUAL_MEMORY("NINL", tail, 4);
+    TEST_ASSERT_EQUAL_UINT8(NL_TRAILER_VERSION, tail[4]);
+    TEST_ASSERT_EQUAL_STRING("e27_rgb", (const char *)&tail[5]);
+    TEST_ASSERT_EQUAL_STRING("1.2.3", (const char *)&tail[21]);
+    TEST_ASSERT_EQUAL_UINT8_ARRAY(HASH, &tail[37], 32);
+    for (uint32_t i = 69; i < NL_TRAILER_SIZE; i++)
+        TEST_ASSERT_EQUAL_HEX8(0xFF, tail[i]);
+}
+
+static void test_build_rejects_too_long_strings(void)
+{
+    fill_hash();
+    TEST_ASSERT_FALSE(nl_trailer_build(tail, "0123456789abcdef", "1.0", HASH)); /* 16 chars, no room for NUL */
+    TEST_ASSERT_FALSE(nl_trailer_build(tail, "evk", "0123456789abcdef", HASH));
+    TEST_ASSERT_TRUE(nl_trailer_build(tail, "012345678901234", "012345678901234", HASH)); /* 15 chars fit */
+}
+
+static void test_verify_accepts_matching(void)
+{
+    fill_hash();
+    nl_trailer_build(tail, "evk", "1.0.0", HASH);
+    TEST_ASSERT_EQUAL(NL_TRAILER_OK, nl_trailer_verify(tail, NL_TRAILER_SIZE, "evk", HASH));
+}
+
+static void test_verify_rejects(void)
+{
+    char version[NL_TRAILER_VERSION_LEN];
+    uint8_t other[32];
+
+    fill_hash();
+    memcpy(other, HASH, 32);
+    other[5] ^= 0x01;
+    nl_trailer_build(tail, "evk", "1.0.0", HASH);
+
+    TEST_ASSERT_EQUAL(NL_TRAILER_ERR_SIZE, nl_trailer_verify(tail, 256, "evk", HASH));
+    TEST_ASSERT_EQUAL(NL_TRAILER_ERR_DEVICE, nl_trailer_verify(tail, NL_TRAILER_SIZE, "gu10_cw", HASH));
+    TEST_ASSERT_EQUAL(NL_TRAILER_ERR_HASH, nl_trailer_verify(tail, NL_TRAILER_SIZE, "evk", other));
+    nl_trailer_version(tail, version);
+    TEST_ASSERT_EQUAL_STRING("1.0.0", version);
+
+    tail[4] = 2;
+    TEST_ASSERT_EQUAL(NL_TRAILER_ERR_VERSION, nl_trailer_verify(tail, NL_TRAILER_SIZE, "evk", HASH));
+    tail[0] = 'X';
+    TEST_ASSERT_EQUAL(NL_TRAILER_ERR_MAGIC, nl_trailer_verify(tail, NL_TRAILER_SIZE, "evk", HASH));
+}
+
+static void test_verify_needs_terminated_device_string(void)
+{
+    fill_hash();
+    nl_trailer_build(tail, "evk", "1.0.0", HASH);
+    memset(&tail[5], 'a', NL_TRAILER_DEVICE_LEN); /* no NUL inside the field */
+    TEST_ASSERT_EQUAL(NL_TRAILER_ERR_DEVICE, nl_trailer_verify(tail, NL_TRAILER_SIZE, "aaaaaaaaaaaaaaaa", HASH));
+}
+
+static void test_error_names(void)
+{
+    TEST_ASSERT_EQUAL_STRING("trailer", nl_trailer_err_name(NL_TRAILER_ERR_MAGIC));
+    TEST_ASSERT_EQUAL_STRING("trailer", nl_trailer_err_name(NL_TRAILER_ERR_SIZE));
+    TEST_ASSERT_EQUAL_STRING("trailer", nl_trailer_err_name(NL_TRAILER_ERR_VERSION));
+    TEST_ASSERT_EQUAL_STRING("device_mismatch", nl_trailer_err_name(NL_TRAILER_ERR_DEVICE));
+    TEST_ASSERT_EQUAL_STRING("hash", nl_trailer_err_name(NL_TRAILER_ERR_HASH));
+    TEST_ASSERT_NULL(nl_trailer_err_name(NL_TRAILER_OK));
+}
+
+int main(void)
+{
+    UNITY_BEGIN();
+    RUN_TEST(test_build_layout);
+    RUN_TEST(test_build_rejects_too_long_strings);
+    RUN_TEST(test_verify_accepts_matching);
+    RUN_TEST(test_verify_rejects);
+    RUN_TEST(test_verify_needs_terminated_device_string);
+    RUN_TEST(test_error_names);
+    return UNITY_END();
+}