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Fix initialisation of word_pincode

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Jochen Hoenicke 2018-04-04 17:50:20 +02:00 committed by Pavol Rusnak
parent 9c9b4bf5cb
commit f216328987
1 changed files with 46 additions and 3 deletions
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49
firmware/recovery.c
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@ -90,6 +90,29 @@ static uint16_t word_pincode;
*/
static uint8_t word_matrix[9];
/* The words are stored in two tables.
*
* The low bits of the first table (TABLE1) store the index into the
* second table, for each of the 81 choices for the first two levels
* of the matrix. The final entry points to the final entry of the
* second table. The difference TABLE1(idx+1)-TABLE1(idx) gives the
* number of choices for the third level. The value
* TABLE2(TABLE1(idx)) gives the index of the first word in the range
* and TABLE2(TABLE1(idx+1))-1 gives the index of the last word.
*
* The low bits of the second table (TABLE2) store the index into the
* word list for each of the choices for the first three levels. The
* final entry stores the value 2048 (number of bip39 words). table.
* The difference TABLE2(idx+1)-TABLE2(idx) gives the number of
* choices for the last level. The value TABLE2(idx) gives the index
* of the first word in the range and TABLE2(idx)-1 gives the index of
* the last word.
*
* The high bits in each table is the "prefix length", i.e. the number
* of significant letters for the corresponding choice. There is no
* prefix length or table for the very first level, as the prefix length
* is always one and there are always nine choices on the second level.
*/
#define MASK_IDX(x) ((x) & 0xfff)
#define TABLE1(x) MASK_IDX(word_table1[x])
#define TABLE2(x) MASK_IDX(word_table2[x])
@ -199,7 +222,7 @@ static void recovery_done(void) {
* first[prefixlen-2] == last[prefixlen-2] except for range WI-Z.
*/
static void add_choice(char choice[12], int prefixlen, const char *first, const char *last) {
// assert prefixlen < 4
// assert 1 <= prefixlen <= 4
char *dest = choice;
for (int i = 0; i < prefixlen; i++) {
*dest++ = toupper((int) first[i]);
@ -293,17 +316,28 @@ static void next_matrix(void) {
uint32_t idx, num;
bool last = (word_index % 4) == 3;
/* Build the matrix:
* num: number of choices
* word_choices[][]: the strings containing the choices
*/
switch (word_index % 4) {
case 3:
/* last level: show up to six words */
/* idx: index in table2 for the entered choice. */
/* first: the first word. */
/* num: the number of words to choose from. */
idx = TABLE1(word_pincode / 9) + word_pincode % 9;
const uint32_t first = word_table2[idx] & 0xfff;
num = (word_table2[idx + 1] & 0xfff) - first;
const uint32_t first = TABLE2(idx);
num = TABLE2(idx + 1) - first;
for (uint32_t i = 0; i < num; i++) {
strlcpy(word_choices[i], wl[first + i], sizeof(word_choices[i]));
}
break;
case 2:
/* third level: show up to nine ranges (using table2) */
/* idx: first index in table2 corresponding to pin code. */
/* num: the number of choices. */
idx = TABLE1(word_pincode);
num = TABLE1(word_pincode + 1) - idx;
for (uint32_t i = 0; i < num; i++) {
@ -314,6 +348,9 @@ static void next_matrix(void) {
break;
case 1:
/* second level: exactly nine ranges (using table1) */
/* idx: first index in table1 corresponding to pin code. */
/* num: the number of choices. */
idx = word_pincode * 9;
num = 9;
for (uint32_t i = 0; i < num; i++) {
@ -324,6 +361,8 @@ static void next_matrix(void) {
break;
case 0:
/* first level: exactly nine ranges */
/* num: the number of choices. */
num = 9;
for (uint32_t i = 0; i < num; i++) {
add_choice(word_choices[i], 1,
@ -364,12 +403,15 @@ static void recovery_digit(const char digit) {
int choice = word_matrix[digit - '1'];
if ((word_index % 4) == 3) {
/* received final word */
/* Mark the chosen word for 250 ms */
int y = 54 - ((digit - '1')/3)*11;
int x = 64 * (((digit - '1') % 3) > 0);
oledInvert(x + 1, y, x + 62, y + 9);
oledRefresh();
usbSleep(250);
/* index of the chosen word */
int idx = TABLE2(TABLE1(word_pincode / 9) + (word_pincode % 9)) + choice;
uint32_t widx = word_index / 4;
@ -430,6 +472,7 @@ void recovery_init(uint32_t _word_count, bool passphrase_protection, bool pin_pr
if ((type & RecoveryDeviceType_RecoveryDeviceType_Matrix) != 0) {
awaiting_word = 2;
word_index = 0;
word_pincode = 0;
next_matrix();
} else {
for (uint32_t i = 0; i < word_count; i++) {