@brief Generate authentication nonce for OTA @param nonce Output buffer for nonce (64 characters for SHA256)
| 914 | /// @brief Generate authentication nonce for OTA |
| 915 | /// @param nonce Output buffer for nonce (64 characters for SHA256) |
| 916 | static void generateNonce(char* nonce, size_t len) { |
| 917 | // Generate nonce from timestamp and random data |
| 918 | unsigned char hash[32]; |
| 919 | mbedtls_sha256_context ctx; |
| 920 | mbedtls_sha256_init(&ctx); |
| 921 | mbedtls_sha256_starts(&ctx, 0); // 0 = SHA256 (not SHA224) |
| 922 | |
| 923 | u32 seed = esp_random(); |
| 924 | mbedtls_sha256_update(&ctx, (unsigned char*)&seed, sizeof(seed)); |
| 925 | |
| 926 | i64 time_us = esp_timer_get_time(); |
| 927 | mbedtls_sha256_update(&ctx, (unsigned char*)&time_us, sizeof(time_us)); |
| 928 | |
| 929 | mbedtls_sha256_finish(&ctx, hash); |
| 930 | mbedtls_sha256_free(&ctx); |
| 931 | |
| 932 | // Convert to hex string |
| 933 | for (size_t i = 0; i < 32 && i * 2 + 1 < len; i++) { |
| 934 | fl::snprintf(nonce + i * 2, 3, "%02x", hash[i]); |
| 935 | } |
| 936 | } |
| 937 | |
| 938 | /// @brief Verify OTA authentication response |
| 939 | /// @param password Password to verify against |
nothing calls this directly
no test coverage detected