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Tweak HCA bruteforcer

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This commit is contained in:
bnnm 2020-11-15 22:44:04 +01:00
parent ac357845b1
commit 061dd7f289
1 changed files with 22 additions and 11 deletions
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33
src/meta/hca.c
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@ -181,9 +181,10 @@ done:
static void bruteforce_hca_key(STREAMFILE* sf, hca_codec_data* hca_data, unsigned long long* out_keycode, uint16_t subkey) {
STREAMFILE* sf_keys = NULL;
uint8_t* buf = NULL;
int best_score = -1;
int best_score = 0xFFFFFF, cur_score;
off_t keys_size, bytes;
int pos;
uint64_t old_key = 0;
VGM_LOG("HCA: test keys\n");
@ -202,9 +203,12 @@ static void bruteforce_hca_key(STREAMFILE* sf, hca_codec_data* hca_data, unsigne
bytes = read_streamfile(buf, 0, keys_size, sf_keys);
if (bytes != keys_size) goto done;
VGM_LOG("HCA: start\n");
pos = 0;
while (pos < keys_size - 4) {
uint64_t key;
VGM_ASSERT(pos % 0x1000000 == 0, "HCA: pos %x...\n", pos);
/* keys are usually u32le lower, u32le upper (u64le) but other orders may exist */
key = ((uint64_t)get_u32le(buf + pos + 0x00) << 0 ) | ((uint64_t)get_u32le(buf + pos + 0x04) << 32);
@ -213,25 +217,32 @@ static void bruteforce_hca_key(STREAMFILE* sf, hca_codec_data* hca_data, unsigne
//key = ((uint64_t)get_u32be(buf + pos + 0x00) << 32) | ((uint64_t)get_u32be(buf + pos + 0x04) << 0);
//key = ((uint64_t)get_u32le(buf + pos + 0x00) << 0 ) | 0; /* upper bytes not set, ex. P5 */
//key = ((uint64_t)get_u32be(buf + pos + 0x00) << 0 ) | 0; /* upper bytes not set, ex. P5 */
if (key == 0)
continue;
test_key(hca_data, key, subkey, &best_score, out_keycode);
if (best_score == 1)
/* observed files have aligned keys, change if needed */
pos += 0x04; //pos++;
if (key == 0 || key == old_key)
continue;
old_key = key;
cur_score = 0;
test_key(hca_data, key, subkey, &cur_score, out_keycode);
if (cur_score == 1)
goto done;
VGM_ASSERT(pos % 0x100000 == 0, "HCA: pos %x...\n", pos);
/* observed files have aligned keys in the .text section, change if needed */
pos += 0x04;
//pos++;
if (cur_score > 0 && cur_score <= 500) {
VGM_LOG("HCA: possible key=%08x%08x (score=%i) at %x\n",
(uint32_t)((key >> 32) & 0xFFFFFFFF), (uint32_t)(key & 0xFFFFFFFF), cur_score, pos-0x04);
if (best_score > cur_score)
best_score = cur_score;
}
}
done:
VGM_ASSERT(best_score > 0, "HCA: best key=%08x%08x (score=%i)\n",
(uint32_t)((*out_keycode >> 32) & 0xFFFFFFFF), (uint32_t)(*out_keycode & 0xFFFFFFFF), best_score);
VGM_ASSERT(best_score < 0, "HCA: key not found\n");
close_streamfile(sf_keys);
free(buf);
}