storage: add has_pin and change_pin

TODO: finish change_pin

embed/extmod/modtrezorconfig/modtrezorconfig.c

@@ -44,6 +44,36 @@ STATIC mp_obj_t mod_trezorconfig_unlock(mp_obj_t pin) {
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_1(mod_trezorconfig_unlock_obj, mod_trezorconfig_unlock);
 
+/// def has_pin() -> bool:
+///     '''
+///     Returns True if storage has a configured PIN, False otherwise.
+///     '''
+STATIC mp_obj_t mod_trezorconfig_has_pin(void) {
+    if (storage_has_pin()) {
+        return mp_const_true;
+    } else {
+        return mp_const_false;
+    }
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_0(mod_trezorconfig_has_pin_obj, mod_trezorconfig_has_pin);
+
+/// def change_pin(pin: str, newpin: str) -> bool:
+///     '''
+///     Change PIN. Returns True on success, False on failure.
+///     '''
+STATIC mp_obj_t mod_trezorconfig_change_pin(mp_obj_t pin, mp_obj_t newpin) {
+    mp_buffer_info_t pinbuf;
+    mp_get_buffer_raise(pin, &pinbuf, MP_BUFFER_READ);
+    mp_buffer_info_t newbuf;
+    mp_get_buffer_raise(newpin, &newbuf, MP_BUFFER_READ);
+    bool r = storage_change_pin(pinbuf.buf, pinbuf.len, newbuf.buf, newbuf.len);
+    if (!r) {
+        return mp_const_false;
+    }
+    return mp_const_true;
+}
+STATIC MP_DEFINE_CONST_FUN_OBJ_2(mod_trezorconfig_change_pin_obj, mod_trezorconfig_change_pin);
+
 /// def get(app: int, key: int) -> bytes:
 ///     '''
 ///     Gets a value of given key for given app (or empty bytes if not set).
@@ -97,6 +127,8 @@ STATIC const mp_rom_map_elem_t mp_module_trezorconfig_globals_table[] = {
     { MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_trezorconfig) },
     { MP_ROM_QSTR(MP_QSTR_init), MP_ROM_PTR(&mod_trezorconfig_init_obj) },
     { MP_ROM_QSTR(MP_QSTR_unlock), MP_ROM_PTR(&mod_trezorconfig_unlock_obj) },
+    { MP_ROM_QSTR(MP_QSTR_has_pin), MP_ROM_PTR(&mod_trezorconfig_has_pin_obj) },
+    { MP_ROM_QSTR(MP_QSTR_change_pin), MP_ROM_PTR(&mod_trezorconfig_change_pin_obj) },
     { MP_ROM_QSTR(MP_QSTR_get), MP_ROM_PTR(&mod_trezorconfig_get_obj) },
     { MP_ROM_QSTR(MP_QSTR_set), MP_ROM_PTR(&mod_trezorconfig_set_obj) },
     { MP_ROM_QSTR(MP_QSTR_wipe), MP_ROM_PTR(&mod_trezorconfig_wipe_obj) },

embed/extmod/modtrezorconfig/storage.c

@@ -24,6 +24,9 @@ static bool unlocked = false;
 
 bool storage_init(void)
 {
+    if (!flash_init()) {
+        return false;
+    }
     if (!norcow_init()) {
         return false;
     }
@@ -112,12 +115,10 @@ static bool const_cmp(const uint8_t *pub, size_t publen, const uint8_t *sec, siz
 
 static bool pin_check(const uint8_t *pin, size_t pinlen)
 {
-    const void *st_pin;
-    uint16_t st_pinlen;
-    if (!norcow_get(PIN_KEY, &st_pin, &st_pinlen)) {
-        return false;
-    }
-    return const_cmp(pin, pinlen, st_pin, (size_t)st_pinlen);
+    const void *spin = NULL;
+    uint16_t spinlen = 0;
+    norcow_get(PIN_KEY, &spin, &spinlen);
+    return const_cmp(pin, pinlen, spin, (size_t)spinlen);
 }
 
 bool storage_unlock(const uint8_t *pin, size_t len)
@@ -182,6 +183,33 @@ bool storage_set(uint16_t key, const void *val, uint16_t len)
     return norcow_set(key, val, len);
 }
 
+bool storage_has_pin(void)
+{
+    if (!initialized) {
+        return false;
+    }
+    const void *spin = NULL;
+    uint16_t spinlen = 0;
+    norcow_get(PIN_KEY, &spin, &spinlen);
+    return spinlen != 0;
+}
+
+bool storage_change_pin(const uint8_t *pin, size_t len, const uint8_t *newpin, size_t newlen)
+{
+    if (!initialized) {
+        return false;
+    }
+    if (!unlocked) {
+        // shutdown();
+        return false;
+    }
+    if (!pin_check(pin, len)) {
+        return false;
+    }
+    // TODO
+    return true;
+}
+
 bool storage_wipe(void)
 {
     return norcow_wipe();

embed/extmod/modtrezorconfig/storage.h

@@ -11,5 +11,7 @@
 bool storage_init(void);
 bool storage_wipe(void);
 bool storage_unlock(const uint8_t *pin, size_t len);
+bool storage_has_pin(void);
+bool storage_change_pin(const uint8_t *pin, size_t len, const uint8_t *newpin, size_t newlen);
 bool storage_get(uint16_t key, const void **val, uint16_t *len);
 bool storage_set(uint16_t key, const void *val, uint16_t len);