faces/totp: decode secrets when setting up

This allows the user to easily copy the base32 encoded secrets
into the TOTP record initializers. They will be decoded once
at runtime when the face is being set up by the movement framework.

Also rename the array of TOTP records to credentials. Much better.

1 files changed, 32 insertions, 19 deletions

diff --git a/movement/watch_faces/complication/totp_face.c b/movement/watch_faces/complication/totp_face.c
index 97c1ffeb..83126a1a 100644
--- a/movement/watch_faces/complication/totp_face.c
+++ b/movement/watch_faces/complication/totp_face.c
@@ -36,19 +36,20 @@
 #include "watch.h"
 #include "watch_utility.h"
 #include "TOTP.h"
+#include "base32.h"
 
 typedef struct {
     unsigned char labels[2];
     hmac_alg algorithm;
     uint32_t period;
     size_t key_length;
-    uint8_t *key;
+    unsigned char *key;
 } totp_t;
 
 #define TOTP_INITIALIZER(label_1, label_2, key_array, algo, timestep) \
     (const totp_t) { \
-        .key = (key_array), \
-        .key_length = sizeof(key_array), \
+        .key = ((unsigned char *) key_array), \
+        .key_length = sizeof(key_array) - 1, \
         .period = (timestep), \
         .labels = { (label_1), (label_2) }, \
         .algorithm = (algo), \
@@ -57,28 +58,20 @@ typedef struct {
 ////////////////////////////////////////////////////////////////////////////////
 // Enter your TOTP key data below
 
-static uint8_t key_1[] = {
-    0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x21, 0xde, 0xad, 0xbe, 0xef, // 1 - JBSWY3DPEHPK3PXP
-};
-
-static uint8_t key_2[] = {
-    0x48, 0x65, 0x6c, 0x6c, 0x6f, 0x21, 0xde, 0xad, 0xbe, 0xef, // 2 - JBSWY3DPEHPK3PXP
-};
-
-static totp_t totp_data[] = {
-    TOTP_INITIALIZER('2', 'F', key_1, SHA1, 30),
-    TOTP_INITIALIZER('A', 'C', key_2, SHA1, 30),
+static totp_t credentials[] = {
+    TOTP_INITIALIZER('2', 'F', "JBSWY3DPEHPK3PXP", SHA1, 30),
+    TOTP_INITIALIZER('A', 'C', "JBSWY3DPEHPK3PXP", SHA1, 30),
 };
 
 // END OF KEY DATA.
 ////////////////////////////////////////////////////////////////////////////////
 
 static inline totp_t *_totp_current(totp_state_t *totp_state) {
-    return &totp_data[totp_state->current_index];
+    return &credentials[totp_state->current_index];
 }
 
-static inline size_t _totp_num(void) {
-    return sizeof(totp_data) / sizeof(*totp_data);
+static inline size_t totp_total(void) {
+    return sizeof(credentials) / sizeof(*credentials);
 }
 
 static void _update_display(totp_state_t *totp_state) {
@@ -98,10 +91,30 @@ static void _update_display(totp_state_t *totp_state) {
     watch_display_string(buf, 0);
 }
 
+static void totp_face_decode_secrets(void) {
+    for (size_t n = totp_total(), i = 0; i < n; ++i) {
+        totp_t *totp = &credentials[i];
+        unsigned char *key = totp->key;
+
+        totp->key = malloc(UNBASE32_LEN(totp->key_length));
+        totp->key_length = base32_decode(key, totp->key);
+
+        if (totp->key_length == 0) {
+            free(totp->key);
+            continue;
+        }
+    }
+}
+
 void totp_face_setup(movement_settings_t *settings, uint8_t watch_face_index, void ** context_ptr) {
     (void) settings;
     (void) watch_face_index;
-    if (*context_ptr == NULL) *context_ptr = malloc(sizeof(totp_state_t));
+
+    if (*context_ptr == NULL) {
+        totp_state_t *totp = malloc(sizeof(totp_state_t));
+        totp_face_decode_secrets();
+        *context_ptr = totp;
+    }
 }
 
 void totp_face_activate(movement_settings_t *settings, void *context) {
@@ -129,7 +142,7 @@ bool totp_face_loop(movement_event_t event, movement_settings_t *settings, void
             movement_move_to_face(0);
             break;
         case EVENT_ALARM_BUTTON_UP:
-            if (totp_state->current_index + 1 < _totp_num()) {
+            if (totp_state->current_index + 1 < totp_total()) {
                 totp_state->current_index++;
             } else {
                 // wrap around to first key