system/core/netsvc/device_id.cpp

// Copyright 2017 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <stdio.h>
#include <string.h>

#include "device_id.h"
#include "eff_short_wordlist_1.h"

#define APPEND_WORD(NUM, SEP)                                                                      \
    word = dictionary[(NUM) % DICEWARE_DICTIONARY_SIZE];                                           \
    memcpy(dest, word, strlen(word));                                                              \
    dest += strlen(word);                                                                          \
    *dest = SEP;                                                                                   \
    dest++;

void device_id_get(unsigned char mac[6], char out[DEVICE_ID_MAX]) {
    const char* word;
    char* dest = out;
    APPEND_WORD(mac[0] | ((mac[4] << 8) & 0xF00), '-');
    APPEND_WORD(mac[1] | ((mac[5] << 8) & 0xF00), '-');
    APPEND_WORD(mac[2] | ((mac[4] << 4) & 0xF00), '-');
    APPEND_WORD(mac[3] | ((mac[5] << 4) & 0xF00), 0);
}