Fix XTS implementation, now verified working on HW.

This commit is contained in:
Michael Scire 2018-03-31 14:29:59 -06:00
parent 9f36769b12
commit 19178d6176

View file

@ -386,6 +386,18 @@ void shift_left_xor_rb(uint8_t *key) {
}
}
void shift_left_xor_rb_le(uint8_t *key) {
uint8_t prev_high_bit = 0;
for (unsigned int i = 0; i < 0x10; i++) {
uint8_t cur_byte = key[i];
key[i] = (cur_byte << 1) | (prev_high_bit);
prev_high_bit = cur_byte >> 7;
}
if (prev_high_bit) {
key[0x0] ^= 0x87;
}
}
void aes_128_xts_nintendo_get_tweak(uint8_t *tweak, size_t sector) {
for (int i = 0xF; i >= 0; i--) { /* Nintendo LE custom tweak... */
tweak[i] = (unsigned char)(sector & 0xFF);
@ -405,7 +417,7 @@ void aes_128_xts_nintendo_xor_with_tweak(unsigned int keyslot, size_t sector, ui
for (unsigned int i = 0; i < 0x10; i++) {
dst[(block << 4) | i] = src[(block << 4) | i] ^ tweak[i];
}
shift_left_xor_rb(tweak);
shift_left_xor_rb_le(tweak);
}
}
@ -439,7 +451,7 @@ void se_aes_128_xts_nintendo_encrypt(unsigned int keyslot_1, unsigned int keyslo
}
size_t sector = base_sector;
for (size_t ofs = 0; ofs < size; ofs += sector_size) {
aes_128_xts_nintendo_crypt_sector(keyslot_1, keyslot_2, sector, true, dst, src, sector_size);
aes_128_xts_nintendo_crypt_sector(keyslot_1, keyslot_2, sector, true, dst + ofs, src + ofs, sector_size);
sector++;
}
}
@ -451,7 +463,7 @@ void se_aes_128_xts_nintendo_decrypt(unsigned int keyslot_1, unsigned int keyslo
}
size_t sector = base_sector;
for (size_t ofs = 0; ofs < size; ofs += sector_size) {
aes_128_xts_nintendo_crypt_sector(keyslot_1, keyslot_2, sector, false, dst, src, sector_size);
aes_128_xts_nintendo_crypt_sector(keyslot_1, keyslot_2, sector, false, dst + ofs, src + ofs, sector_size);
sector++;
}
}