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ncch_container: support encrypted games

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This commit is contained in:
wwylele
2018-07-28 18:30:54 +03:00
parent b92660435c
commit d4a808c885
17 changed files with 319 additions and 103 deletions
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193
src/core/file_sys/ncch_container.cpp
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@@ -5,10 +5,13 @@
#include <cinttypes>
#include <cstring>
#include <memory>
#include <cryptopp/aes.h>
#include <cryptopp/modes.h>
#include "common/common_types.h"
#include "common/logging/log.h"
#include "core/core.h"
#include "core/file_sys/ncch_container.h"
#include "core/hw/aes/key.h"
#include "core/loader/loader.h"
////////////////////////////////////////////////////////////////////////////////////////////////////
@@ -142,6 +145,116 @@ Loader::ResultStatus NCCHContainer::Load() {
return Loader::ResultStatus::ErrorInvalidFormat;
has_header = true;
bool failed_to_decrypt = false;
if (!ncch_header.no_crypto) {
is_encrypted = true;
// Find primary and secondary keys
if (ncch_header.fixed_key) {
LOG_DEBUG(Service_FS, "Fixed-key crypto");
primary_key.fill(0);
secondary_key.fill(0);
} else {
using namespace HW::AES;
InitKeys();
std::array<u8, 16> key_y_primary, key_y_secondary;
std::copy(ncch_header.signature, ncch_header.signature + key_y_primary.size(),
key_y_primary.begin());
if (!ncch_header.seed_crypto) {
key_y_secondary = key_y_primary;
} else {
// Seed crypto is unimplemented.
LOG_ERROR(Service_FS, "Unsupported seed crypto");
failed_to_decrypt = true;
}
SetKeyY(KeySlotID::NCCHSecure1, key_y_primary);
if (!IsNormalKeyAvailable(KeySlotID::NCCHSecure1)) {
LOG_ERROR(Service_FS, "Secure1 KeyX missing");
failed_to_decrypt = true;
}
primary_key = GetNormalKey(KeySlotID::NCCHSecure1);
switch (ncch_header.secondary_key_slot) {
case 0:
LOG_DEBUG(Service_FS, "Secure1 crypto");
secondary_key = primary_key;
break;
case 1:
LOG_DEBUG(Service_FS, "Secure2 crypto");
SetKeyY(KeySlotID::NCCHSecure2, key_y_secondary);
if (!IsNormalKeyAvailable(KeySlotID::NCCHSecure2)) {
LOG_ERROR(Service_FS, "Secure2 KeyX missing");
failed_to_decrypt = true;
}
secondary_key = GetNormalKey(KeySlotID::NCCHSecure2);
break;
case 10:
LOG_DEBUG(Service_FS, "Secure3 crypto");
SetKeyY(KeySlotID::NCCHSecure3, key_y_secondary);
if (!IsNormalKeyAvailable(KeySlotID::NCCHSecure3)) {
LOG_ERROR(Service_FS, "Secure3 KeyX missing");
failed_to_decrypt = true;
}
secondary_key = GetNormalKey(KeySlotID::NCCHSecure3);
break;
case 11:
LOG_DEBUG(Service_FS, "Secure4 crypto");
SetKeyY(KeySlotID::NCCHSecure4, key_y_secondary);
if (!IsNormalKeyAvailable(KeySlotID::NCCHSecure4)) {
LOG_ERROR(Service_FS, "Secure4 KeyX missing");
failed_to_decrypt = true;
}
secondary_key = GetNormalKey(KeySlotID::NCCHSecure4);
break;
}
}
// Find CTR for each section
// Written with reference to
// https://github.com/d0k3/GodMode9/blob/99af6a73be48fa7872649aaa7456136da0df7938/arm9/source/game/ncch.c#L34-L52
if (ncch_header.version == 0 || ncch_header.version == 2) {
LOG_DEBUG(Loader, "NCCH version 0/2");
// In this version, CTR for each section is a magic number prefixed by partition ID
// (reverse order)
std::reverse_copy(ncch_header.partition_id, ncch_header.partition_id + 8,
exheader_ctr.begin());
exefs_ctr = romfs_ctr = exheader_ctr;
exheader_ctr[8] = 1;
exefs_ctr[8] = 2;
romfs_ctr[8] = 3;
} else if (ncch_header.version == 1) {
LOG_DEBUG(Loader, "NCCH version 1");
// In this version, CTR for each section is the section offset prefixed by partition
// ID, as if the entire NCCH image is encrypted using a single CTR stream.
std::copy(ncch_header.partition_id, ncch_header.partition_id + 8,
exheader_ctr.begin());
exefs_ctr = romfs_ctr = exheader_ctr;
auto u32ToBEArray = [](u32 value) -> std::array<u8, 4> {
return std::array<u8, 4>{
static_cast<u8>(value >> 24),
static_cast<u8>((value >> 16) & 0xFF),
static_cast<u8>((value >> 8) & 0xFF),
static_cast<u8>(value & 0xFF),
};
};
auto offset_exheader = u32ToBEArray(0x200); // exheader offset
auto offset_exefs = u32ToBEArray(ncch_header.exefs_offset * kBlockSize);
auto offset_romfs = u32ToBEArray(ncch_header.romfs_offset * kBlockSize);
std::copy(offset_exheader.begin(), offset_exheader.end(),
exheader_ctr.begin() + 12);
std::copy(offset_exefs.begin(), offset_exefs.end(), exefs_ctr.begin() + 12);
std::copy(offset_romfs.begin(), offset_romfs.end(), romfs_ctr.begin() + 12);
} else {
LOG_ERROR(Service_FS, "Unknown NCCH version {}", ncch_header.version);
failed_to_decrypt = true;
}
} else {
LOG_DEBUG(Service_FS, "No crypto");
is_encrypted = false;
}
// System archives and DLC don't have an extended header but have RomFS
if (ncch_header.extended_header_size) {
@@ -149,6 +262,26 @@ Loader::ResultStatus NCCHContainer::Load() {
sizeof(ExHeader_Header))
return Loader::ResultStatus::Error;
if (is_encrypted) {
// This ID check is masked to low 32-bit as a toleration to ill-formed ROM created
// by merging games and its updates.
if ((exheader_header.system_info.jump_id & 0xFFFFFFFF) ==
(ncch_header.program_id & 0xFFFFFFFF)) {
LOG_WARNING(Service_FS, "NCCH is marked as encrypted but with decrypted "
"exheader. Force no crypto scheme.");
is_encrypted = false;
} else {
if (failed_to_decrypt) {
LOG_ERROR(Service_FS, "Failed to decrypt");
return Loader::ResultStatus::ErrorEncrypted;
}
CryptoPP::byte* data = reinterpret_cast<CryptoPP::byte*>(&exheader_header);
CryptoPP::CTR_Mode<CryptoPP::AES>::Decryption(
primary_key.data(), primary_key.size(), exheader_ctr.data())
.ProcessData(data, data, sizeof(exheader_header));
}
}
is_compressed = (exheader_header.codeset_info.flags.flag & 1) == 1;
u32 entry_point = exheader_header.codeset_info.text.address;
u32 code_size = exheader_header.codeset_info.text.code_size;
@@ -173,12 +306,6 @@ Loader::ResultStatus NCCHContainer::Load() {
LOG_DEBUG(Service_FS, "System Mode: {}",
static_cast<int>(exheader_header.arm11_system_local_caps.system_mode));
if (exheader_header.system_info.jump_id != ncch_header.program_id) {
LOG_ERROR(Service_FS,
"ExHeader Program ID mismatch: the ROM is probably encrypted.");
return Loader::ResultStatus::ErrorEncrypted;
}
has_exheader = true;
}
@@ -194,6 +321,13 @@ Loader::ResultStatus NCCHContainer::Load() {
if (file.ReadBytes(&exefs_header, sizeof(ExeFs_Header)) != sizeof(ExeFs_Header))
return Loader::ResultStatus::Error;
if (is_encrypted) {
CryptoPP::byte* data = reinterpret_cast<CryptoPP::byte*>(&exefs_header);
CryptoPP::CTR_Mode<CryptoPP::AES>::Decryption(primary_key.data(),
primary_key.size(), exefs_ctr.data())
.ProcessData(data, data, sizeof(exefs_header));
}
exefs_file = FileUtil::IOFile(filepath, "rb");
has_exefs = true;
}
@@ -293,6 +427,17 @@ Loader::ResultStatus NCCHContainer::LoadSectionExeFS(const char* name, std::vect
(section.offset + exefs_offset + sizeof(ExeFs_Header) + ncch_offset);
exefs_file.Seek(section_offset, SEEK_SET);
std::array<u8, 16> key;
if (strcmp(section.name, "icon") == 0 || strcmp(section.name, "banner") == 0) {
key = primary_key;
} else {
key = secondary_key;
}
CryptoPP::CTR_Mode<CryptoPP::AES>::Decryption dec(key.data(), key.size(),
exefs_ctr.data());
dec.Seek(section.offset + sizeof(ExeFs_Header));
if (strcmp(section.name, ".code") == 0 && is_compressed) {
// Section is compressed, read compressed .code section...
std::unique_ptr<u8[]> temp_buffer;
@@ -305,6 +450,10 @@ Loader::ResultStatus NCCHContainer::LoadSectionExeFS(const char* name, std::vect
if (exefs_file.ReadBytes(&temp_buffer[0], section.size) != section.size)
return Loader::ResultStatus::Error;
if (is_encrypted) {
dec.ProcessData(&temp_buffer[0], &temp_buffer[0], section.size);
}
// Decompress .code section...
u32 decompressed_size = LZSS_GetDecompressedSize(&temp_buffer[0], section.size);
buffer.resize(decompressed_size);
@@ -315,6 +464,9 @@ Loader::ResultStatus NCCHContainer::LoadSectionExeFS(const char* name, std::vect
buffer.resize(section.size);
if (exefs_file.ReadBytes(&buffer[0], section.size) != section.size)
return Loader::ResultStatus::Error;
if (is_encrypted) {
dec.ProcessData(&buffer[0], &buffer[0], section.size);
}
}
return Loader::ResultStatus::Success;
}
@@ -354,13 +506,12 @@ Loader::ResultStatus NCCHContainer::LoadOverrideExeFSSection(const char* name,
return Loader::ResultStatus::ErrorNotUsed;
}
Loader::ResultStatus NCCHContainer::ReadRomFS(std::shared_ptr<FileUtil::IOFile>& romfs_file,
u64& offset, u64& size) {
Loader::ResultStatus NCCHContainer::ReadRomFS(std::shared_ptr<RomFSReader>& romfs_file) {
Loader::ResultStatus result = Load();
if (result != Loader::ResultStatus::Success)
return result;
if (ReadOverrideRomFS(romfs_file, offset, size) == Loader::ResultStatus::Success)
if (ReadOverrideRomFS(romfs_file) == Loader::ResultStatus::Success)
return Loader::ResultStatus::Success;
if (!has_romfs) {
@@ -381,26 +532,30 @@ Loader::ResultStatus NCCHContainer::ReadRomFS(std::shared_ptr<FileUtil::IOFile>&
return Loader::ResultStatus::Error;
// We reopen the file, to allow its position to be independent from file's
romfs_file = std::make_shared<FileUtil::IOFile>(filepath, "rb");
if (!romfs_file->IsOpen())
FileUtil::IOFile romfs_file_inner(filepath, "rb");
if (!romfs_file_inner.IsOpen())
return Loader::ResultStatus::Error;
offset = romfs_offset;
size = romfs_size;
if (is_encrypted) {
romfs_file = std::make_shared<RomFSReader>(std::move(romfs_file_inner), romfs_offset,
romfs_size, secondary_key, romfs_ctr, 0x1000);
} else {
romfs_file =
std::make_shared<RomFSReader>(std::move(romfs_file_inner), romfs_offset, romfs_size);
}
return Loader::ResultStatus::Success;
}
Loader::ResultStatus NCCHContainer::ReadOverrideRomFS(std::shared_ptr<FileUtil::IOFile>& romfs_file,
u64& offset, u64& size) {
Loader::ResultStatus NCCHContainer::ReadOverrideRomFS(std::shared_ptr<RomFSReader>& romfs_file) {
// Check for RomFS overrides
std::string split_filepath = filepath + ".romfs";
if (FileUtil::Exists(split_filepath)) {
romfs_file = std::make_shared<FileUtil::IOFile>(split_filepath, "rb");
if (romfs_file->IsOpen()) {
FileUtil::IOFile romfs_file_inner(split_filepath, "rb");
if (romfs_file_inner.IsOpen()) {
LOG_WARNING(Service_FS, "File {} overriding built-in RomFS", split_filepath);
offset = 0;
size = romfs_file->GetSize();
romfs_file = std::make_shared<RomFSReader>(std::move(romfs_file_inner), 0,
romfs_file_inner.GetSize());
return Loader::ResultStatus::Success;
}
}