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batch extract mode
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@khang06
khang06 committed Jul 31, 2021
1 parent 4f18b5e commit a7d939a
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Showing 2 changed files with 62 additions and 19 deletions.
1 change: 1 addition & 0 deletions blkstuff/blkstuff.vcxproj
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Original file line number Diff line number Diff line change
Expand Up @@ -132,6 +132,7 @@
<PreprocessorDefinitions>NDEBUG;_CONSOLE;%(PreprocessorDefinitions)</PreprocessorDefinitions>
<ConformanceMode>true</ConformanceMode>
<DisableSpecificWarnings>4996</DisableSpecificWarnings>
<LanguageStandard>stdcpp17</LanguageStandard>
</ClCompile>
<Link>
<SubSystem>Console</SubSystem>
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80 changes: 61 additions & 19 deletions blkstuff/main.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -3,6 +3,7 @@
#include <string.h>

#include <random>
#include <filesystem>

#include <lz4.h>

Expand Down Expand Up @@ -180,7 +181,7 @@ void mhy0_header_scramble(uint8_t* input, uint64_t a2, uint8_t* input2, uint64_t
}
}

void mhy0_extract(int block_index, uint8_t* input, size_t input_size) {
void mhy0_extract(const char* out_format, int block_index, uint8_t* input, size_t input_size) {
// loosely based on UnityPlayer:$1C64C0
// TODO: bounds checks
if (*(uint32_t*)input != 0x3079686D) { // mhy0
Expand All @@ -189,7 +190,7 @@ void mhy0_extract(int block_index, uint8_t* input, size_t input_size) {
}

uint32_t size = *(uint32_t*)(input + 4);
printf("first size 0x%x\n", size);
//printf("first size 0x%x\n", size);

auto* data = new uint8_t[size];
memcpy(data, input + 8, size);
Expand All @@ -205,7 +206,7 @@ void mhy0_extract(int block_index, uint8_t* input, size_t input_size) {
// TODO: there is a different path for calculating this, so this might mess up on some inputs
//uint32_t decomp_size = MAKE_UINT32(data[0x20 + 1], data[0x20 + 6], data[0x20 + 3], data[0x20 + 2]);
uint32_t decomp_size = MAKE_UINT32(data, 0x20 + 1, 0x20 + 6, 0x20 + 3, 0x20 + 2);
printf("decompressed size: 0x%x\n", decomp_size);
//printf("decompressed size: 0x%x\n", decomp_size);
uint8_t* decomp_output = new uint8_t[decomp_size];
auto lz4_res = LZ4_decompress_safe((const char*)(data + 0x27), (char*)decomp_output, size - 0x27, decomp_size);
if (lz4_res < 0) {
Expand All @@ -217,12 +218,12 @@ void mhy0_extract(int block_index, uint8_t* input, size_t input_size) {

//printf("next data cmp size: 0x%x\n", MAKE_UINT32(decomp_output, 0x11F + 2, 0x11F + 4, 0x11F, 0x11F + 5));
//printf("next data decmp size: 0x%x\n", MAKE_UINT32(decomp_output, 0x112 + 1, 0x112 + 6, 0x112 + 3, 0x112 + 2));
printf("unknown 1: 0x%x\n", MAKE_UINT32(decomp_output, 0x10C + 2, 0x10C + 4, 0x10C, 0x10C + 5));
//printf("unknown 1: 0x%x\n", MAKE_UINT32(decomp_output, 0x10C + 2, 0x10C + 4, 0x10C, 0x10C + 5));
auto cab_count = MAKE_UINT32(decomp_output, 2, 4, 0, 5);
printf("cab count: 0x%x\n", cab_count);
//printf("cab count: 0x%x\n", cab_count);
//auto entry_count = MAKE_UINT32(decomp_output, 0x119 + 2, 0x119 + 4, 0x119, 0x119 + 5);
auto entry_count = MAKE_UINT32(decomp_output, cab_count * 0x113 + 6 + 2, cab_count * 0x113 + 6 + 4, cab_count * 0x113 + 6, cab_count * 0x113 + 6 + 5);
printf("entry count: 0x%x\n", entry_count);
//printf("entry count: 0x%x\n", entry_count);
//dump_to_file("bruh.bin", decomp_output, decomp_size);
//hexdump("asdf", decomp_output, decomp_size);
//exit(1);
Expand All @@ -234,10 +235,11 @@ void mhy0_extract(int block_index, uint8_t* input, size_t input_size) {

uint8_t* entry_ptr = input + 0x8 + size;
char filename[0x100] = {};
snprintf(filename, sizeof(filename), "output%d.bin", block_index);
//printf("%s\n", out_format);
snprintf(filename, sizeof(filename), out_format, block_index);
auto* output = fopen(filename, "wb");
if (!output) {
printf("failed to open output.bin\n");
printf("failed to open %s\n", filename);
exit(1);
}
for (int i = 0; i < entry_count; i++) {
Expand Down Expand Up @@ -266,14 +268,10 @@ void mhy0_extract(int block_index, uint8_t* input, size_t input_size) {
delete[] decomp_output;
}

int main(int argc, char** argv) {
int extract_blk(char* in_filename, const char* out_format) {
//auto* blk_file = fopen("D:\\genshinimpactre\\1.5-dev\\YuanShen_Data\\StreamingAssets\\20527480.blk", "rb");
//auto* blk_file = fopen("D:\\Games\\Genshin Impact\\Genshin Impact game\\GenshinImpact_Data\\StreamingAssets\\VideoAssets\\26236578.blk", "rb");
if (argc < 2) {
printf("you need an input file\n");
return 1;
}
auto* blk_file = fopen(argv[1], "rb");
auto* blk_file = fopen(in_filename, "rb");
if (!blk_file) {
printf("failed to open blk\n");
return 1;
Expand All @@ -300,19 +298,19 @@ int main(int argc, char** argv) {
uint8_t key[16] = {};
fread(key, sizeof(key), 1, blk_file);
fseek(blk_file, 16, SEEK_CUR); // skip the useless half of the key
hexdump("encrypted blk key:", key, sizeof(key));
//hexdump("encrypted blk key:", key, sizeof(key));
key_scramble1(key);
key_scramble2(key);
// this should also go into magic_constants.h, but it's small
// this value goes through a lot of computation to get generated, but is always the same
uint8_t hard_key[] = { 0xE3, 0xFC, 0x2D, 0x26, 0x9C, 0xC5, 0xA2, 0xEC, 0xD3, 0xF8, 0xC6, 0xD3, 0x77, 0xC2, 0x49, 0xB9 };
for (int i = 0; i < 16; i++)
key[i] ^= hard_key[i];
hexdump("decrypted blk key:", key, sizeof(key));
//hexdump("decrypted blk key:", key, sizeof(key));

uint16_t block_size = 0;
fread(&block_size, sizeof(block_size), 1, blk_file);
printf("0x%x\n", block_size);
//printf("0x%x\n", block_size);

fseek(blk_file, 0, SEEK_END);
size_t size = ftell(blk_file);
Expand Down Expand Up @@ -347,8 +345,8 @@ int main(int argc, char** argv) {
if (res) {
auto loc = (uint8_t*)res - data;
mhy0_locs.push_back(loc);
printf("found mhy0 at 0x%llx\n", loc);
mhy0_extract(i, data + loc, size);
//printf("found mhy0 at 0x%llx\n", loc);
mhy0_extract(out_format, i, data + loc, size);
last_loc = loc + 4;
} else {
break;
Expand All @@ -358,4 +356,48 @@ int main(int argc, char** argv) {
//mhy0_extract(data, size);

delete[] data;
}

int main(int argc, char** argv) {
if (argc < 2) {
printf("you need an input file\n");
return 1;
}
if (!strcmp(argv[1], "batch")) {
if (argc < 4) {
printf("you need input and output folders for batch mode\n");
return 1;
}

auto base_path = std::filesystem::path(argv[2]);
std::vector<std::filesystem::path> blk_paths;
printf("scanning for blks\n");
try {
for (auto& p : std::filesystem::recursive_directory_iterator(base_path)) {
if (p.path().extension() == ".blk")
//printf("%ws\n", p.path().lexically_relative(base_path).c_str());
blk_paths.push_back(p.path().lexically_relative(base_path));
}
} catch (const std::exception& e) {
printf("failed to search for blk files with error: %s\n", e.what());
return 1;
}
printf("found %llu blks to extract\n", blk_paths.size());

auto output_base = std::filesystem::path(argv[3]);
for (auto& p : blk_paths) {
printf("processing %ws...", p.c_str());

auto input_path = base_path / p;
auto output_path = (output_base / p).replace_extension(".%d.bin");
auto output_dir = std::filesystem::path(output_path).remove_filename();
//printf("%ws\n", output_path.c_str());
std::filesystem::create_directories(output_dir);
extract_blk((char*)input_path.generic_string().c_str(), output_path.generic_string().c_str());

printf("ok\n");
}
} else {
extract_blk(argv[1], "output%d.bin");
}
}

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