2024-07-06 08:52:41 -04:00

248 lines
7.7 KiB
C

/* SPDX-License-Identifier: MIT */
/*
* MIT License
*
* Copyright © 2021 Wesley Ellis (https://github.com/tahnok)
* Copyright © 2021-2023 Joey Castillo <joeycastillo@utexas.edu>
* Copyright © 2022 Jack Bond-Preston <jackbondpreston@outlook.com>
* Copyright © 2023 Alex Utter <ooterness@gmail.com>
* Copyright © 2023 Emilien Court <emilien.court@telecomnancy.net>
* Copyright © 2023 Jeremy O'Brien <neutral@fastmail.com>
* Copyright © 2024 Matheus Afonso Martins Moreira <matheus.a.m.moreira@gmail.com> (https://www.matheusmoreira.com/)
* Copyright © 2024 Max Zettlmeißl <max@zettlmeissl.de>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#include <stdlib.h>
#include <string.h>
#include "totp_face.h"
#include "watch.h"
#include "watch_utility.h"
#include "TOTP.h"
#include "base32.h"
#ifndef TOTP_FACE_MAX_KEY_LENGTH
#define TOTP_FACE_MAX_KEY_LENGTH 128
#endif
typedef struct {
unsigned char labels[2];
hmac_alg algorithm;
uint32_t period;
size_t encoded_key_length;
unsigned char *encoded_key;
} totp_t;
#define CREDENTIAL(label, key_array, algo, timestep) \
(const totp_t) { \
.encoded_key = ((unsigned char *) key_array), \
.encoded_key_length = sizeof(key_array) - 1, \
.period = (timestep), \
.labels = (#label), \
.algorithm = (algo), \
}
////////////////////////////////////////////////////////////////////////////////
// Enter your TOTP key data below
static totp_t credentials[] = {
CREDENTIAL(2F, "JBSWY3DPEHPK3PXP", SHA1, 30),
CREDENTIAL(AC, "JBSWY3DPEHPK3PXP", SHA1, 30),
};
// END OF KEY DATA.
////////////////////////////////////////////////////////////////////////////////
static inline totp_t *totp_at(size_t i) {
return &credentials[i];
}
static inline totp_t *totp_current(totp_state_t *totp_state) {
return totp_at(totp_state->current_index);
}
static inline size_t totp_total(void) {
return sizeof(credentials) / sizeof(*credentials);
}
static void totp_validate_key_lengths(void) {
for (size_t n = totp_total(), i = 0; i < n; ++i) {
totp_t *totp = totp_at(i);
if (UNBASE32_LEN(totp->encoded_key_length) > TOTP_FACE_MAX_KEY_LENGTH) {
// Key exceeds static limits, turn it off by zeroing the length
totp->encoded_key_length = 0;
}
}
}
static void totp_generate(totp_state_t *totp_state) {
totp_t *totp = totp_current(totp_state);
if (totp->encoded_key_length <= 0) {
// Key exceeded static limits and was turned off
totp_state->current_decoded_key_length = 0;
return;
}
totp_state->current_decoded_key_length = base32_decode(totp->encoded_key, totp_state->current_decoded_key);
if (totp_state->current_decoded_key_length == 0) {
// Decoding failed for some reason
// Not a base 32 string?
return;
}
TOTP(
totp_state->current_decoded_key,
totp_state->current_decoded_key_length,
totp->period,
totp->algorithm
);
}
static void totp_display_error(totp_state_t *totp_state) {
char buf[10 + 1];
totp_t *totp = totp_current(totp_state);
snprintf(buf, sizeof(buf), "%c%c ERROR ", totp->labels[0], totp->labels[1]);
watch_display_string(buf, 0);
}
static void totp_display_code(totp_state_t *totp_state) {
char buf[14];
div_t result;
uint8_t valid_for;
totp_t *totp = totp_current(totp_state);
result = div(totp_state->timestamp, totp->period);
if (result.quot != totp_state->steps) {
totp_state->current_code = getCodeFromTimestamp(totp_state->timestamp);
totp_state->steps = result.quot;
}
valid_for = totp->period - result.rem;
sprintf(buf, "%c%c%2d%06lu", totp->labels[0], totp->labels[1], valid_for, totp_state->current_code);
watch_display_string(buf, 0);
}
static void totp_display(totp_state_t *totp_state) {
if (totp_state->current_decoded_key_length > 0) {
totp_display_code(totp_state);
} else {
totp_display_error(totp_state);
}
}
static void totp_generate_and_display(totp_state_t *totp_state) {
totp_generate(totp_state);
totp_display(totp_state);
}
static inline uint32_t totp_compute_base_timestamp(movement_settings_t *settings) {
return watch_utility_date_time_to_unix_time(watch_rtc_get_date_time(), movement_timezone_offsets[settings->bit.time_zone] * 60);
}
void totp_face_setup(movement_settings_t *settings, uint8_t watch_face_index, void ** context_ptr) {
(void) settings;
(void) watch_face_index;
totp_validate_key_lengths();
if (*context_ptr == NULL) {
totp_state_t *totp = malloc(sizeof(totp_state_t));
totp->current_decoded_key = malloc(TOTP_FACE_MAX_KEY_LENGTH);
*context_ptr = totp;
}
}
void totp_face_activate(movement_settings_t *settings, void *context) {
(void) settings;
totp_state_t *totp = (totp_state_t *) context;
totp->timestamp = totp_compute_base_timestamp(settings);
totp->steps = 0;
totp->current_code = 0;
totp->current_index = 0;
totp->current_decoded_key_length = 0;
// totp->current_decoded_key is already initialized in setup
totp_generate_and_display(totp);
}
bool totp_face_loop(movement_event_t event, movement_settings_t *settings, void *context) {
(void) settings;
totp_state_t *totp_state = (totp_state_t *) context;
switch (event.event_type) {
case EVENT_TICK:
totp_state->timestamp++;
// fall through
case EVENT_ACTIVATE:
totp_display(totp_state);
break;
case EVENT_TIMEOUT:
movement_move_to_face(0);
break;
case EVENT_ALARM_BUTTON_UP:
if ((size_t)totp_state->current_index + 1 < totp_total()) {
totp_state->current_index++;
} else {
// wrap around to first key
totp_state->current_index = 0;
}
totp_generate_and_display(totp_state);
break;
case EVENT_LIGHT_BUTTON_UP:
if (totp_state->current_index == 0) {
// Wrap around to the last credential.
totp_state->current_index = totp_total() - 1;
} else {
totp_state->current_index--;
}
totp_generate_and_display(totp_state);
break;
case EVENT_ALARM_BUTTON_DOWN:
case EVENT_ALARM_LONG_PRESS:
case EVENT_LIGHT_BUTTON_DOWN:
break;
case EVENT_LIGHT_LONG_PRESS:
movement_illuminate_led();
break;
default:
movement_default_loop_handler(event, settings);
break;
}
return true;
}
void totp_face_resign(movement_settings_t *settings, void *context) {
(void) settings;
(void) context;
}