15 files changed, 827 insertions, 64 deletions

diff --git a/src/core/file_sys/card_image.cpp b/src/core/file_sys/card_image.cpp
new file mode 100644
index 000000000..395eea8ae
--- /dev/null
+++ b/src/core/file_sys/card_image.cpp
@@ -0,0 +1,149 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <array>
+#include <string>
+#include <core/loader/loader.h>
+#include "core/file_sys/card_image.h"
+#include "core/file_sys/partition_filesystem.h"
+#include "core/file_sys/vfs_offset.h"
+
+namespace FileSys {
+
+XCI::XCI(VirtualFile file_) : file(std::move(file_)), partitions(0x4) {
+    if (file->ReadObject(&header) != sizeof(GamecardHeader)) {
+        status = Loader::ResultStatus::ErrorInvalidFormat;
+        return;
+    }
+
+    if (header.magic != Common::MakeMagic('H', 'E', 'A', 'D')) {
+        status = Loader::ResultStatus::ErrorInvalidFormat;
+        return;
+    }
+
+    PartitionFilesystem main_hfs(
+        std::make_shared<OffsetVfsFile>(file, header.hfs_size, header.hfs_offset));
+
+    if (main_hfs.GetStatus() != Loader::ResultStatus::Success) {
+        status = main_hfs.GetStatus();
+        return;
+    }
+
+    static constexpr std::array<const char*, 0x4> partition_names = {"update", "normal", "secure",
+                                                                     "logo"};
+
+    for (XCIPartition partition :
+         {XCIPartition::Update, XCIPartition::Normal, XCIPartition::Secure, XCIPartition::Logo}) {
+        auto raw = main_hfs.GetFile(partition_names[static_cast<size_t>(partition)]);
+        if (raw != nullptr)
+            partitions[static_cast<size_t>(partition)] = std::make_shared<PartitionFilesystem>(raw);
+    }
+
+    auto result = AddNCAFromPartition(XCIPartition::Secure);
+    if (result != Loader::ResultStatus::Success) {
+        status = result;
+        return;
+    }
+
+    result = AddNCAFromPartition(XCIPartition::Update);
+    if (result != Loader::ResultStatus::Success) {
+        status = result;
+        return;
+    }
+
+    result = AddNCAFromPartition(XCIPartition::Normal);
+    if (result != Loader::ResultStatus::Success) {
+        status = result;
+        return;
+    }
+
+    if (GetFormatVersion() >= 0x2) {
+        result = AddNCAFromPartition(XCIPartition::Logo);
+        if (result != Loader::ResultStatus::Success) {
+            status = result;
+            return;
+        }
+    }
+
+    status = Loader::ResultStatus::Success;
+}
+
+Loader::ResultStatus XCI::GetStatus() const {
+    return status;
+}
+
+VirtualDir XCI::GetPartition(XCIPartition partition) const {
+    return partitions[static_cast<size_t>(partition)];
+}
+
+VirtualDir XCI::GetSecurePartition() const {
+    return GetPartition(XCIPartition::Secure);
+}
+
+VirtualDir XCI::GetNormalPartition() const {
+    return GetPartition(XCIPartition::Normal);
+}
+
+VirtualDir XCI::GetUpdatePartition() const {
+    return GetPartition(XCIPartition::Update);
+}
+
+VirtualDir XCI::GetLogoPartition() const {
+    return GetPartition(XCIPartition::Logo);
+}
+
+std::shared_ptr<NCA> XCI::GetNCAByType(NCAContentType type) const {
+    const auto iter =
+        std::find_if(ncas.begin(), ncas.end(),
+                     [type](const std::shared_ptr<NCA>& nca) { return nca->GetType() == type; });
+    return iter == ncas.end() ? nullptr : *iter;
+}
+
+VirtualFile XCI::GetNCAFileByType(NCAContentType type) const {
+    auto nca = GetNCAByType(type);
+    if (nca != nullptr)
+        return nca->GetBaseFile();
+    return nullptr;
+}
+
+std::vector<std::shared_ptr<VfsFile>> XCI::GetFiles() const {
+    return {};
+}
+
+std::vector<std::shared_ptr<VfsDirectory>> XCI::GetSubdirectories() const {
+    return std::vector<std::shared_ptr<VfsDirectory>>();
+}
+
+std::string XCI::GetName() const {
+    return file->GetName();
+}
+
+std::shared_ptr<VfsDirectory> XCI::GetParentDirectory() const {
+    return file->GetContainingDirectory();
+}
+
+bool XCI::ReplaceFileWithSubdirectory(VirtualFile file, VirtualDir dir) {
+    return false;
+}
+
+Loader::ResultStatus XCI::AddNCAFromPartition(XCIPartition part) {
+    if (partitions[static_cast<size_t>(part)] == nullptr) {
+        return Loader::ResultStatus::ErrorInvalidFormat;
+    }
+
+    for (const VirtualFile& file : partitions[static_cast<size_t>(part)]->GetFiles()) {
+        if (file->GetExtension() != "nca")
+            continue;
+        auto nca = std::make_shared<NCA>(file);
+        if (nca->GetStatus() == Loader::ResultStatus::Success)
+            ncas.push_back(std::move(nca));
+    }
+
+    return Loader::ResultStatus::Success;
+}
+
+u8 XCI::GetFormatVersion() const {
+    return GetLogoPartition() == nullptr ? 0x1 : 0x2;
+}
+} // namespace FileSys
diff --git a/src/core/file_sys/card_image.h b/src/core/file_sys/card_image.h
new file mode 100644
index 000000000..e089d737c
--- /dev/null
+++ b/src/core/file_sys/card_image.h
@@ -0,0 +1,96 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <array>
+#include <vector>
+#include "common/common_types.h"
+#include "common/swap.h"
+#include "core/file_sys/content_archive.h"
+#include "core/file_sys/vfs.h"
+#include "core/loader/loader.h"
+
+namespace FileSys {
+
+enum class GamecardSize : u8 {
+    S_1GB = 0xFA,
+    S_2GB = 0xF8,
+    S_4GB = 0xF0,
+    S_8GB = 0xE0,
+    S_16GB = 0xE1,
+    S_32GB = 0xE2,
+};
+
+struct GamecardInfo {
+    std::array<u8, 0x70> data;
+};
+static_assert(sizeof(GamecardInfo) == 0x70, "GamecardInfo has incorrect size.");
+
+struct GamecardHeader {
+    std::array<u8, 0x100> signature;
+    u32_le magic;
+    u32_le secure_area_start;
+    u32_le backup_area_start;
+    u8 kek_index;
+    GamecardSize size;
+    u8 header_version;
+    u8 flags;
+    u64_le package_id;
+    u64_le valid_data_end;
+    u128 info_iv;
+    u64_le hfs_offset;
+    u64_le hfs_size;
+    std::array<u8, 0x20> hfs_header_hash;
+    std::array<u8, 0x20> initial_data_hash;
+    u32_le secure_mode_flag;
+    u32_le title_key_flag;
+    u32_le key_flag;
+    u32_le normal_area_end;
+    GamecardInfo info;
+};
+static_assert(sizeof(GamecardHeader) == 0x200, "GamecardHeader has incorrect size.");
+
+enum class XCIPartition : u8 { Update, Normal, Secure, Logo };
+
+class XCI : public ReadOnlyVfsDirectory {
+public:
+    explicit XCI(VirtualFile file);
+
+    Loader::ResultStatus GetStatus() const;
+
+    u8 GetFormatVersion() const;
+
+    VirtualDir GetPartition(XCIPartition partition) const;
+    VirtualDir GetSecurePartition() const;
+    VirtualDir GetNormalPartition() const;
+    VirtualDir GetUpdatePartition() const;
+    VirtualDir GetLogoPartition() const;
+
+    std::shared_ptr<NCA> GetNCAByType(NCAContentType type) const;
+    VirtualFile GetNCAFileByType(NCAContentType type) const;
+
+    std::vector<std::shared_ptr<VfsFile>> GetFiles() const override;
+
+    std::vector<std::shared_ptr<VfsDirectory>> GetSubdirectories() const override;
+
+    std::string GetName() const override;
+
+    std::shared_ptr<VfsDirectory> GetParentDirectory() const override;
+
+protected:
+    bool ReplaceFileWithSubdirectory(VirtualFile file, VirtualDir dir) override;
+
+private:
+    Loader::ResultStatus AddNCAFromPartition(XCIPartition part);
+
+    VirtualFile file;
+    GamecardHeader header{};
+
+    Loader::ResultStatus status;
+
+    std::vector<VirtualDir> partitions;
+    std::vector<std::shared_ptr<NCA>> ncas;
+};
+} // namespace FileSys
diff --git a/src/core/file_sys/content_archive.cpp b/src/core/file_sys/content_archive.cpp
index d6b20c047..3529166ac 100644
--- a/src/core/file_sys/content_archive.cpp
+++ b/src/core/file_sys/content_archive.cpp
@@ -4,9 +4,12 @@
 
 #include <algorithm>
 #include <utility>
-
+#include <boost/optional.hpp>
 #include "common/logging/log.h"
+#include "core/crypto/aes_util.h"
+#include "core/crypto/ctr_encryption_layer.h"
 #include "core/file_sys/content_archive.h"
+#include "core/file_sys/romfs.h"
 #include "core/file_sys/vfs_offset.h"
 #include "core/loader/loader.h"
 
@@ -28,11 +31,19 @@ enum class NCASectionFilesystemType : u8 {
 struct NCASectionHeaderBlock {
     INSERT_PADDING_BYTES(3);
     NCASectionFilesystemType filesystem_type;
-    u8 crypto_type;
+    NCASectionCryptoType crypto_type;
     INSERT_PADDING_BYTES(3);
 };
 static_assert(sizeof(NCASectionHeaderBlock) == 0x8, "NCASectionHeaderBlock has incorrect size.");
 
+struct NCASectionRaw {
+    NCASectionHeaderBlock header;
+    std::array<u8, 0x138> block_data;
+    std::array<u8, 0x8> section_ctr;
+    INSERT_PADDING_BYTES(0xB8);
+};
+static_assert(sizeof(NCASectionRaw) == 0x200, "NCASectionRaw has incorrect size.");
+
 struct PFS0Superblock {
     NCASectionHeaderBlock header_block;
     std::array<u8, 0x20> hash;
@@ -42,79 +53,200 @@ struct PFS0Superblock {
     u64_le hash_table_size;
     u64_le pfs0_header_offset;
     u64_le pfs0_size;
-    INSERT_PADDING_BYTES(432);
+    INSERT_PADDING_BYTES(0x1B0);
 };
 static_assert(sizeof(PFS0Superblock) == 0x200, "PFS0Superblock has incorrect size.");
 
-struct IVFCLevel {
-    u64_le offset;
-    u64_le size;
-    u32_le block_size;
-    u32_le reserved;
-};
-static_assert(sizeof(IVFCLevel) == 0x18, "IVFCLevel has incorrect size.");
-
 struct RomFSSuperblock {
     NCASectionHeaderBlock header_block;
-    u32_le magic;
-    u32_le magic_number;
-    INSERT_PADDING_BYTES(8);
-    std::array<IVFCLevel, 6> levels;
-    INSERT_PADDING_BYTES(64);
+    IVFCHeader ivfc;
+    INSERT_PADDING_BYTES(0x118);
 };
-static_assert(sizeof(RomFSSuperblock) == 0xE8, "RomFSSuperblock has incorrect size.");
+static_assert(sizeof(RomFSSuperblock) == 0x200, "RomFSSuperblock has incorrect size.");
+
+union NCASectionHeader {
+    NCASectionRaw raw;
+    PFS0Superblock pfs0;
+    RomFSSuperblock romfs;
+};
+static_assert(sizeof(NCASectionHeader) == 0x200, "NCASectionHeader has incorrect size.");
+
+bool IsValidNCA(const NCAHeader& header) {
+    // TODO(DarkLordZach): Add NCA2/NCA0 support.
+    return header.magic == Common::MakeMagic('N', 'C', 'A', '3');
+}
+
+u8 NCA::GetCryptoRevision() const {
+    u8 master_key_id = header.crypto_type;
+    if (header.crypto_type_2 > master_key_id)
+        master_key_id = header.crypto_type_2;
+    if (master_key_id > 0)
+        --master_key_id;
+    return master_key_id;
+}
+
+boost::optional<Core::Crypto::Key128> NCA::GetKeyAreaKey(NCASectionCryptoType type) const {
+    const auto master_key_id = GetCryptoRevision();
+
+    if (!keys.HasKey(Core::Crypto::S128KeyType::KeyArea, master_key_id, header.key_index))
+        return boost::none;
+
+    std::vector<u8> key_area(header.key_area.begin(), header.key_area.end());
+    Core::Crypto::AESCipher<Core::Crypto::Key128> cipher(
+        keys.GetKey(Core::Crypto::S128KeyType::KeyArea, master_key_id, header.key_index),
+        Core::Crypto::Mode::ECB);
+    cipher.Transcode(key_area.data(), key_area.size(), key_area.data(), Core::Crypto::Op::Decrypt);
+
+    Core::Crypto::Key128 out;
+    if (type == NCASectionCryptoType::XTS)
+        std::copy(key_area.begin(), key_area.begin() + 0x10, out.begin());
+    else if (type == NCASectionCryptoType::CTR)
+        std::copy(key_area.begin() + 0x20, key_area.begin() + 0x30, out.begin());
+    else
+        LOG_CRITICAL(Crypto, "Called GetKeyAreaKey on invalid NCASectionCryptoType type={:02X}",
+                     static_cast<u8>(type));
+    u128 out_128{};
+    memcpy(out_128.data(), out.data(), 16);
+    LOG_DEBUG(Crypto, "called with crypto_rev={:02X}, kak_index={:02X}, key={:016X}{:016X}",
+              master_key_id, header.key_index, out_128[1], out_128[0]);
+
+    return out;
+}
+
+boost::optional<Core::Crypto::Key128> NCA::GetTitlekey() const {
+    const auto master_key_id = GetCryptoRevision();
+
+    u128 rights_id{};
+    memcpy(rights_id.data(), header.rights_id.data(), 16);
+    if (rights_id == u128{})
+        return boost::none;
+
+    auto titlekey = keys.GetKey(Core::Crypto::S128KeyType::Titlekey, rights_id[1], rights_id[0]);
+    if (titlekey == Core::Crypto::Key128{})
+        return boost::none;
+    Core::Crypto::AESCipher<Core::Crypto::Key128> cipher(
+        keys.GetKey(Core::Crypto::S128KeyType::Titlekek, master_key_id), Core::Crypto::Mode::ECB);
+    cipher.Transcode(titlekey.data(), titlekey.size(), titlekey.data(), Core::Crypto::Op::Decrypt);
+
+    return titlekey;
+}
+
+VirtualFile NCA::Decrypt(NCASectionHeader s_header, VirtualFile in, u64 starting_offset) const {
+    if (!encrypted)
+        return in;
+
+    switch (s_header.raw.header.crypto_type) {
+    case NCASectionCryptoType::NONE:
+        LOG_DEBUG(Crypto, "called with mode=NONE");
+        return in;
+    case NCASectionCryptoType::CTR:
+        LOG_DEBUG(Crypto, "called with mode=CTR, starting_offset={:016X}", starting_offset);
+        {
+            boost::optional<Core::Crypto::Key128> key = boost::none;
+            if (std::find_if_not(header.rights_id.begin(), header.rights_id.end(),
+                                 [](char c) { return c == 0; }) == header.rights_id.end()) {
+                key = GetKeyAreaKey(NCASectionCryptoType::CTR);
+            } else {
+                key = GetTitlekey();
+            }
+
+            if (key == boost::none)
+                return nullptr;
+            auto out = std::make_shared<Core::Crypto::CTREncryptionLayer>(
+                std::move(in), key.value(), starting_offset);
+            std::vector<u8> iv(16);
+            for (u8 i = 0; i < 8; ++i)
+                iv[i] = s_header.raw.section_ctr[0x8 - i - 1];
+            out->SetIV(iv);
+            return std::static_pointer_cast<VfsFile>(out);
+        }
+    case NCASectionCryptoType::XTS:
+        // TODO(DarkLordZach): Implement XTSEncryptionLayer.
+    default:
+        LOG_ERROR(Crypto, "called with unhandled crypto type={:02X}",
+                  static_cast<u8>(s_header.raw.header.crypto_type));
+        return nullptr;
+    }
+}
 
 NCA::NCA(VirtualFile file_) : file(std::move(file_)) {
     if (sizeof(NCAHeader) != file->ReadObject(&header))
-        LOG_CRITICAL(Loader, "File reader errored out during header read.");
+        LOG_ERROR(Loader, "File reader errored out during header read.");
+
+    encrypted = false;
 
     if (!IsValidNCA(header)) {
-        status = Loader::ResultStatus::ErrorInvalidFormat;
-        return;
+        NCAHeader dec_header{};
+        Core::Crypto::AESCipher<Core::Crypto::Key256> cipher(
+            keys.GetKey(Core::Crypto::S256KeyType::Header), Core::Crypto::Mode::XTS);
+        cipher.XTSTranscode(&header, sizeof(NCAHeader), &dec_header, 0, 0x200,
+                            Core::Crypto::Op::Decrypt);
+        if (IsValidNCA(dec_header)) {
+            header = dec_header;
+            encrypted = true;
+        } else {
+            if (!keys.HasKey(Core::Crypto::S256KeyType::Header))
+                status = Loader::ResultStatus::ErrorMissingKeys;
+            else
+                status = Loader::ResultStatus::ErrorDecrypting;
+            return;
+        }
     }
 
-    std::ptrdiff_t number_sections =
+    const std::ptrdiff_t number_sections =
         std::count_if(std::begin(header.section_tables), std::end(header.section_tables),
                       [](NCASectionTableEntry entry) { return entry.media_offset > 0; });
 
+    std::vector<NCASectionHeader> sections(number_sections);
+    const auto length_sections = SECTION_HEADER_SIZE * number_sections;
+
+    if (encrypted) {
+        auto raw = file->ReadBytes(length_sections, SECTION_HEADER_OFFSET);
+        Core::Crypto::AESCipher<Core::Crypto::Key256> cipher(
+            keys.GetKey(Core::Crypto::S256KeyType::Header), Core::Crypto::Mode::XTS);
+        cipher.XTSTranscode(raw.data(), length_sections, sections.data(), 2, SECTION_HEADER_SIZE,
+                            Core::Crypto::Op::Decrypt);
+    } else {
+        file->ReadBytes(sections.data(), length_sections, SECTION_HEADER_OFFSET);
+    }
+
     for (std::ptrdiff_t i = 0; i < number_sections; ++i) {
-        // Seek to beginning of this section.
-        NCASectionHeaderBlock block{};
-        if (sizeof(NCASectionHeaderBlock) !=
-            file->ReadObject(&block, SECTION_HEADER_OFFSET + i * SECTION_HEADER_SIZE))
-            LOG_CRITICAL(Loader, "File reader errored out during header read.");
-
-        if (block.filesystem_type == NCASectionFilesystemType::ROMFS) {
-            RomFSSuperblock sb{};
-            if (sizeof(RomFSSuperblock) !=
-                file->ReadObject(&sb, SECTION_HEADER_OFFSET + i * SECTION_HEADER_SIZE))
-                LOG_CRITICAL(Loader, "File reader errored out during header read.");
+        auto section = sections[i];
 
+        if (section.raw.header.filesystem_type == NCASectionFilesystemType::ROMFS) {
             const size_t romfs_offset =
                 header.section_tables[i].media_offset * MEDIA_OFFSET_MULTIPLIER +
-                sb.levels[IVFC_MAX_LEVEL - 1].offset;
-            const size_t romfs_size = sb.levels[IVFC_MAX_LEVEL - 1].size;
-            files.emplace_back(std::make_shared<OffsetVfsFile>(file, romfs_size, romfs_offset));
-            romfs = files.back();
-        } else if (block.filesystem_type == NCASectionFilesystemType::PFS0) {
-            PFS0Superblock sb{};
-            // Seek back to beginning of this section.
-            if (sizeof(PFS0Superblock) !=
-                file->ReadObject(&sb, SECTION_HEADER_OFFSET + i * SECTION_HEADER_SIZE))
-                LOG_CRITICAL(Loader, "File reader errored out during header read.");
-
+                section.romfs.ivfc.levels[IVFC_MAX_LEVEL - 1].offset;
+            const size_t romfs_size = section.romfs.ivfc.levels[IVFC_MAX_LEVEL - 1].size;
+            auto dec =
+                Decrypt(section, std::make_shared<OffsetVfsFile>(file, romfs_size, romfs_offset),
+                        romfs_offset);
+            if (dec != nullptr) {
+                files.push_back(std::move(dec));
+                romfs = files.back();
+            } else {
+                status = Loader::ResultStatus::ErrorMissingKeys;
+                return;
+            }
+        } else if (section.raw.header.filesystem_type == NCASectionFilesystemType::PFS0) {
             u64 offset = (static_cast<u64>(header.section_tables[i].media_offset) *
                           MEDIA_OFFSET_MULTIPLIER) +
-                         sb.pfs0_header_offset;
+                         section.pfs0.pfs0_header_offset;
             u64 size = MEDIA_OFFSET_MULTIPLIER * (header.section_tables[i].media_end_offset -
                                                   header.section_tables[i].media_offset);
-            auto npfs = std::make_shared<PartitionFilesystem>(
-                std::make_shared<OffsetVfsFile>(file, size, offset));
+            auto dec =
+                Decrypt(section, std::make_shared<OffsetVfsFile>(file, size, offset), offset);
+            if (dec != nullptr) {
+                auto npfs = std::make_shared<PartitionFilesystem>(std::move(dec));
 
-            if (npfs->GetStatus() == Loader::ResultStatus::Success) {
-                dirs.emplace_back(npfs);
-                if (IsDirectoryExeFS(dirs.back()))
-                    exefs = dirs.back();
+                if (npfs->GetStatus() == Loader::ResultStatus::Success) {
+                    dirs.push_back(std::move(npfs));
+                    if (IsDirectoryExeFS(dirs.back()))
+                        exefs = dirs.back();
+                }
+            } else {
+                status = Loader::ResultStatus::ErrorMissingKeys;
+                return;
             }
         }
     }
@@ -164,6 +296,10 @@ VirtualDir NCA::GetExeFS() const {
     return exefs;
 }
 
+VirtualFile NCA::GetBaseFile() const {
+    return file;
+}
+
 bool NCA::ReplaceFileWithSubdirectory(VirtualFile file, VirtualDir dir) {
     return false;
 }
diff --git a/src/core/file_sys/content_archive.h b/src/core/file_sys/content_archive.h
index 0b8b9db61..a8879d9a8 100644
--- a/src/core/file_sys/content_archive.h
+++ b/src/core/file_sys/content_archive.h
@@ -8,14 +8,18 @@
 #include <memory>
 #include <string>
 #include <vector>
-
+#include <boost/optional.hpp>
 #include "common/common_funcs.h"
 #include "common/common_types.h"
 #include "common/swap.h"
+#include "core/crypto/key_manager.h"
 #include "core/file_sys/partition_filesystem.h"
+#include "core/loader/loader.h"
 
 namespace FileSys {
 
+union NCASectionHeader;
+
 enum class NCAContentType : u8 {
     Program = 0,
     Meta = 1,
@@ -24,6 +28,13 @@ enum class NCAContentType : u8 {
     Data = 4,
 };
 
+enum class NCASectionCryptoType : u8 {
+    NONE = 1,
+    XTS = 2,
+    CTR = 3,
+    BKTR = 4,
+};
+
 struct NCASectionTableEntry {
     u32_le media_offset;
     u32_le media_end_offset;
@@ -48,7 +59,7 @@ struct NCAHeader {
     std::array<u8, 0x10> rights_id;
     std::array<NCASectionTableEntry, 0x4> section_tables;
     std::array<std::array<u8, 0x20>, 0x4> hash_tables;
-    std::array<std::array<u8, 0x10>, 0x4> key_area;
+    std::array<u8, 0x40> key_area;
     INSERT_PADDING_BYTES(0xC0);
 };
 static_assert(sizeof(NCAHeader) == 0x400, "NCAHeader has incorrect size.");
@@ -58,10 +69,7 @@ inline bool IsDirectoryExeFS(const std::shared_ptr<VfsDirectory>& pfs) {
     return pfs->GetFile("main") != nullptr && pfs->GetFile("main.npdm") != nullptr;
 }
 
-inline bool IsValidNCA(const NCAHeader& header) {
-    return header.magic == Common::MakeMagic('N', 'C', 'A', '2') ||
-           header.magic == Common::MakeMagic('N', 'C', 'A', '3');
-}
+bool IsValidNCA(const NCAHeader& header);
 
 // An implementation of VfsDirectory that represents a Nintendo Content Archive (NCA) conatiner.
 // After construction, use GetStatus to determine if the file is valid and ready to be used.
@@ -81,10 +89,17 @@ public:
     VirtualFile GetRomFS() const;
     VirtualDir GetExeFS() const;
 
+    VirtualFile GetBaseFile() const;
+
 protected:
     bool ReplaceFileWithSubdirectory(VirtualFile file, VirtualDir dir) override;
 
 private:
+    u8 GetCryptoRevision() const;
+    boost::optional<Core::Crypto::Key128> GetKeyAreaKey(NCASectionCryptoType type) const;
+    boost::optional<Core::Crypto::Key128> GetTitlekey() const;
+    VirtualFile Decrypt(NCASectionHeader header, VirtualFile in, u64 starting_offset) const;
+
     std::vector<VirtualDir> dirs;
     std::vector<VirtualFile> files;
 
@@ -95,6 +110,10 @@ private:
     NCAHeader header{};
 
     Loader::ResultStatus status{};
+
+    bool encrypted;
+
+    Core::Crypto::KeyManager keys;
 };
 
 } // namespace FileSys
diff --git a/src/core/file_sys/partition_filesystem.cpp b/src/core/file_sys/partition_filesystem.cpp
index 521e21078..47e032b19 100644
--- a/src/core/file_sys/partition_filesystem.cpp
+++ b/src/core/file_sys/partition_filesystem.cpp
@@ -97,9 +97,8 @@ void PartitionFilesystem::PrintDebugInfo() const {
     LOG_DEBUG(Service_FS, "Magic:                  {:.4}", pfs_header.magic);
     LOG_DEBUG(Service_FS, "Files:                  {}", pfs_header.num_entries);
     for (u32 i = 0; i < pfs_header.num_entries; i++) {
-        LOG_DEBUG(Service_FS, " > File {}:              {} (0x{:X} bytes, at 0x{:X})", i,
-                  pfs_files[i]->GetName(), pfs_files[i]->GetSize(),
-                  dynamic_cast<OffsetVfsFile*>(pfs_files[i].get())->GetOffset());
+        LOG_DEBUG(Service_FS, " > File {}:              {} (0x{:X} bytes)", i,
+                  pfs_files[i]->GetName(), pfs_files[i]->GetSize());
     }
 }
 
diff --git a/src/core/file_sys/romfs.cpp b/src/core/file_sys/romfs.cpp
new file mode 100644
index 000000000..ff3ddb29c
--- /dev/null
+++ b/src/core/file_sys/romfs.cpp
@@ -0,0 +1,124 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include "common/common_types.h"
+#include "common/swap.h"
+#include "core/file_sys/romfs.h"
+#include "core/file_sys/vfs.h"
+#include "core/file_sys/vfs_offset.h"
+#include "core/file_sys/vfs_vector.h"
+
+namespace FileSys {
+
+constexpr u32 ROMFS_ENTRY_EMPTY = 0xFFFFFFFF;
+
+struct TableLocation {
+    u64_le offset;
+    u64_le size;
+};
+static_assert(sizeof(TableLocation) == 0x10, "TableLocation has incorrect size.");
+
+struct RomFSHeader {
+    u64_le header_size;
+    TableLocation directory_hash;
+    TableLocation directory_meta;
+    TableLocation file_hash;
+    TableLocation file_meta;
+    u64_le data_offset;
+};
+static_assert(sizeof(RomFSHeader) == 0x50, "RomFSHeader has incorrect size.");
+
+struct DirectoryEntry {
+    u32_le sibling;
+    u32_le child_dir;
+    u32_le child_file;
+    u32_le hash;
+    u32_le name_length;
+};
+static_assert(sizeof(DirectoryEntry) == 0x14, "DirectoryEntry has incorrect size.");
+
+struct FileEntry {
+    u32_le parent;
+    u32_le sibling;
+    u64_le offset;
+    u64_le size;
+    u32_le hash;
+    u32_le name_length;
+};
+static_assert(sizeof(FileEntry) == 0x20, "FileEntry has incorrect size.");
+
+template <typename Entry>
+static std::pair<Entry, std::string> GetEntry(const VirtualFile& file, size_t offset) {
+    Entry entry{};
+    if (file->ReadObject(&entry, offset) != sizeof(Entry))
+        return {};
+    std::string string(entry.name_length, '\0');
+    if (file->ReadArray(&string[0], string.size(), offset + sizeof(Entry)) != string.size())
+        return {};
+    return {entry, string};
+}
+
+void ProcessFile(VirtualFile file, size_t file_offset, size_t data_offset, u32 this_file_offset,
+                 std::shared_ptr<VectorVfsDirectory> parent) {
+    while (true) {
+        auto entry = GetEntry<FileEntry>(file, file_offset + this_file_offset);
+
+        parent->AddFile(std::make_shared<OffsetVfsFile>(
+            file, entry.first.size, entry.first.offset + data_offset, entry.second, parent));
+
+        if (entry.first.sibling == ROMFS_ENTRY_EMPTY)
+            break;
+
+        this_file_offset = entry.first.sibling;
+    }
+}
+
+void ProcessDirectory(VirtualFile file, size_t dir_offset, size_t file_offset, size_t data_offset,
+                      u32 this_dir_offset, std::shared_ptr<VectorVfsDirectory> parent) {
+    while (true) {
+        auto entry = GetEntry<DirectoryEntry>(file, dir_offset + this_dir_offset);
+        auto current = std::make_shared<VectorVfsDirectory>(
+            std::vector<VirtualFile>{}, std::vector<VirtualDir>{}, parent, entry.second);
+
+        if (entry.first.child_file != ROMFS_ENTRY_EMPTY) {
+            ProcessFile(file, file_offset, data_offset, entry.first.child_file, current);
+        }
+
+        if (entry.first.child_dir != ROMFS_ENTRY_EMPTY) {
+            ProcessDirectory(file, dir_offset, file_offset, data_offset, entry.first.child_dir,
+                             current);
+        }
+
+        parent->AddDirectory(current);
+        if (entry.first.sibling == ROMFS_ENTRY_EMPTY)
+            break;
+        this_dir_offset = entry.first.sibling;
+    }
+}
+
+VirtualDir ExtractRomFS(VirtualFile file) {
+    RomFSHeader header{};
+    if (file->ReadObject(&header) != sizeof(RomFSHeader))
+        return nullptr;
+
+    if (header.header_size != sizeof(RomFSHeader))
+        return nullptr;
+
+    const u64 file_offset = header.file_meta.offset;
+    const u64 dir_offset = header.directory_meta.offset + 4;
+
+    const auto root =
+        std::make_shared<VectorVfsDirectory>(std::vector<VirtualFile>{}, std::vector<VirtualDir>{},
+                                             file->GetContainingDirectory(), file->GetName());
+
+    ProcessDirectory(file, dir_offset, file_offset, header.data_offset, 0, root);
+
+    VirtualDir out = std::move(root);
+
+    while (out->GetSubdirectory("") != nullptr)
+        out = out->GetSubdirectory("");
+
+    return out;
+}
+} // namespace FileSys
diff --git a/src/core/file_sys/romfs.h b/src/core/file_sys/romfs.h
new file mode 100644
index 000000000..03a876d22
--- /dev/null
+++ b/src/core/file_sys/romfs.h
@@ -0,0 +1,35 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <array>
+#include "common/common_funcs.h"
+#include "common/swap.h"
+#include "core/file_sys/vfs.h"
+
+namespace FileSys {
+
+struct IVFCLevel {
+    u64_le offset;
+    u64_le size;
+    u32_le block_size;
+    u32_le reserved;
+};
+static_assert(sizeof(IVFCLevel) == 0x18, "IVFCLevel has incorrect size.");
+
+struct IVFCHeader {
+    u32_le magic;
+    u32_le magic_number;
+    INSERT_PADDING_BYTES(8);
+    std::array<IVFCLevel, 6> levels;
+    INSERT_PADDING_BYTES(64);
+};
+static_assert(sizeof(IVFCHeader) == 0xE0, "IVFCHeader has incorrect size.");
+
+// Converts a RomFS binary blob to VFS Filesystem
+// Returns nullptr on failure
+VirtualDir ExtractRomFS(VirtualFile file);
+
+} // namespace FileSys
diff --git a/src/core/file_sys/vfs.cpp b/src/core/file_sys/vfs.cpp
index b99a4fd5b..dae1c16ef 100644
--- a/src/core/file_sys/vfs.cpp
+++ b/src/core/file_sys/vfs.cpp
@@ -46,6 +46,13 @@ size_t VfsFile::WriteBytes(const std::vector<u8>& data, size_t offset) {
     return Write(data.data(), data.size(), offset);
 }
 
+std::string VfsFile::GetFullPath() const {
+    if (GetContainingDirectory() == nullptr)
+        return "/" + GetName();
+
+    return GetContainingDirectory()->GetFullPath() + "/" + GetName();
+}
+
 std::shared_ptr<VfsFile> VfsDirectory::GetFileRelative(std::string_view path) const {
     auto vec = FileUtil::SplitPathComponents(path);
     vec.erase(std::remove_if(vec.begin(), vec.end(), [](const auto& str) { return str.empty(); }),
@@ -243,6 +250,13 @@ bool VfsDirectory::Copy(std::string_view src, std::string_view dest) {
     return f2->WriteBytes(f1->ReadAllBytes()) == f1->GetSize();
 }
 
+std::string VfsDirectory::GetFullPath() const {
+    if (IsRoot())
+        return GetName();
+
+    return GetParentDirectory()->GetFullPath() + "/" + GetName();
+}
+
 bool ReadOnlyVfsDirectory::IsWritable() const {
     return false;
 }
@@ -270,4 +284,33 @@ bool ReadOnlyVfsDirectory::DeleteFile(std::string_view name) {
 bool ReadOnlyVfsDirectory::Rename(std::string_view name) {
     return false;
 }
+
+bool DeepEquals(const VirtualFile& file1, const VirtualFile& file2, size_t block_size) {
+    if (file1->GetSize() != file2->GetSize())
+        return false;
+
+    std::vector<u8> f1_v(block_size);
+    std::vector<u8> f2_v(block_size);
+    for (size_t i = 0; i < file1->GetSize(); i += block_size) {
+        auto f1_vs = file1->Read(f1_v.data(), block_size, i);
+        auto f2_vs = file2->Read(f2_v.data(), block_size, i);
+
+        if (f1_vs != f2_vs)
+            return false;
+        auto iters = std::mismatch(f1_v.begin(), f1_v.end(), f2_v.begin(), f2_v.end());
+        if (iters.first != f1_v.end() && iters.second != f2_v.end())
+            return false;
+    }
+
+    return true;
+}
+
+bool VfsRawCopy(VirtualFile src, VirtualFile dest) {
+    if (src == nullptr || dest == nullptr)
+        return false;
+    if (!dest->Resize(src->GetSize()))
+        return false;
+    std::vector<u8> data = src->ReadAllBytes();
+    return dest->WriteBytes(data, 0) == data.size();
+}
 } // namespace FileSys
diff --git a/src/core/file_sys/vfs.h b/src/core/file_sys/vfs.h
index 4a13b8378..fab9e2b45 100644
--- a/src/core/file_sys/vfs.h
+++ b/src/core/file_sys/vfs.h
@@ -113,6 +113,9 @@ struct VfsFile : NonCopyable {
 
     // Renames the file to name. Returns whether or not the operation was successsful.
     virtual bool Rename(std::string_view name) = 0;
+
+    // Returns the full path of this file as a string, recursively
+    virtual std::string GetFullPath() const;
 };
 
 // A class representing a directory in an abstract filesystem.
@@ -213,6 +216,17 @@ struct VfsDirectory : NonCopyable {
         return ReplaceFileWithSubdirectory(file_p, std::make_shared<Directory>(file_p));
     }
 
+    bool InterpretAsDirectory(const std::function<VirtualDir(VirtualFile)>& function,
+                              const std::string& file) {
+        auto file_p = GetFile(file);
+        if (file_p == nullptr)
+            return false;
+        return ReplaceFileWithSubdirectory(file_p, function(file_p));
+    }
+
+    // Returns the full path of this directory as a string, recursively
+    virtual std::string GetFullPath() const;
+
 protected:
     // Backend for InterpretAsDirectory.
     // Removes all references to file and adds a reference to dir in the directory's implementation.
@@ -230,4 +244,13 @@ struct ReadOnlyVfsDirectory : public VfsDirectory {
     bool DeleteFile(std::string_view name) override;
     bool Rename(std::string_view name) override;
 };
+
+// Compare the two files, byte-for-byte, in increments specificed by block_size
+bool DeepEquals(const VirtualFile& file1, const VirtualFile& file2, size_t block_size = 0x200);
+
+// A method that copies the raw data between two different implementations of VirtualFile. If you
+// are using the same implementation, it is probably better to use the Copy method in the parent
+// directory of src/dest.
+bool VfsRawCopy(VirtualFile src, VirtualFile dest);
+
 } // namespace FileSys
diff --git a/src/core/file_sys/vfs_offset.cpp b/src/core/file_sys/vfs_offset.cpp
index a40331cef..847cde2f5 100644
--- a/src/core/file_sys/vfs_offset.cpp
+++ b/src/core/file_sys/vfs_offset.cpp
@@ -10,8 +10,9 @@
 namespace FileSys {
 
 OffsetVfsFile::OffsetVfsFile(std::shared_ptr<VfsFile> file_, size_t size_, size_t offset_,
-                             std::string name_)
-    : file(std::move(file_)), offset(offset_), size(size_), name(std::move(name_)) {}
+                             std::string name_, VirtualDir parent_)
+    : file(file_), offset(offset_), size(size_), name(std::move(name_)),
+      parent(parent_ == nullptr ? file->GetContainingDirectory() : std::move(parent_)) {}
 
 std::string OffsetVfsFile::GetName() const {
     return name.empty() ? file->GetName() : name;
@@ -35,7 +36,7 @@ bool OffsetVfsFile::Resize(size_t new_size) {
 }
 
 std::shared_ptr<VfsDirectory> OffsetVfsFile::GetContainingDirectory() const {
-    return file->GetContainingDirectory();
+    return parent;
 }
 
 bool OffsetVfsFile::IsWritable() const {
diff --git a/src/core/file_sys/vfs_offset.h b/src/core/file_sys/vfs_offset.h
index 4f471e3ba..235970dc5 100644
--- a/src/core/file_sys/vfs_offset.h
+++ b/src/core/file_sys/vfs_offset.h
@@ -17,7 +17,7 @@ namespace FileSys {
 // the size of this wrapper.
 struct OffsetVfsFile : public VfsFile {
     OffsetVfsFile(std::shared_ptr<VfsFile> file, size_t size, size_t offset = 0,
-                  std::string new_name = "");
+                  std::string new_name = "", VirtualDir new_parent = nullptr);
 
     std::string GetName() const override;
     size_t GetSize() const override;
@@ -44,6 +44,7 @@ private:
     size_t offset;
     size_t size;
     std::string name;
+    VirtualDir parent;
 };
 
 } // namespace FileSys
diff --git a/src/core/file_sys/vfs_real.cpp b/src/core/file_sys/vfs_real.cpp
index 9ce2e1efa..82d54da4a 100644
--- a/src/core/file_sys/vfs_real.cpp
+++ b/src/core/file_sys/vfs_real.cpp
@@ -195,6 +195,12 @@ bool RealVfsDirectory::Rename(std::string_view name) {
     return FileUtil::Rename(path, new_name);
 }
 
+std::string RealVfsDirectory::GetFullPath() const {
+    auto out = path;
+    std::replace(out.begin(), out.end(), '\\', '/');
+    return out;
+}
+
 bool RealVfsDirectory::ReplaceFileWithSubdirectory(VirtualFile file, VirtualDir dir) {
     const auto iter = std::find(files.begin(), files.end(), file);
     if (iter == files.end())
diff --git a/src/core/file_sys/vfs_real.h b/src/core/file_sys/vfs_real.h
index 2151211c9..243d58576 100644
--- a/src/core/file_sys/vfs_real.h
+++ b/src/core/file_sys/vfs_real.h
@@ -41,7 +41,7 @@ private:
 
 // An implementation of VfsDirectory that represents a directory on the user's computer.
 struct RealVfsDirectory : public VfsDirectory {
-    RealVfsDirectory(const std::string& path, Mode perms);
+    RealVfsDirectory(const std::string& path, Mode perms = Mode::Read);
 
     std::vector<std::shared_ptr<VfsFile>> GetFiles() const override;
     std::vector<std::shared_ptr<VfsDirectory>> GetSubdirectories() const override;
@@ -54,6 +54,7 @@ struct RealVfsDirectory : public VfsDirectory {
     bool DeleteSubdirectory(std::string_view name) override;
     bool DeleteFile(std::string_view name) override;
     bool Rename(std::string_view name) override;
+    std::string GetFullPath() const override;
 
 protected:
     bool ReplaceFileWithSubdirectory(VirtualFile file, VirtualDir dir) override;
diff --git a/src/core/file_sys/vfs_vector.cpp b/src/core/file_sys/vfs_vector.cpp
new file mode 100644
index 000000000..fda603960
--- /dev/null
+++ b/src/core/file_sys/vfs_vector.cpp
@@ -0,0 +1,86 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <algorithm>
+#include <utility>
+#include "core/file_sys/vfs_vector.h"
+
+namespace FileSys {
+VectorVfsDirectory::VectorVfsDirectory(std::vector<VirtualFile> files_,
+                                       std::vector<VirtualDir> dirs_, VirtualDir parent_,
+                                       std::string name_)
+    : files(std::move(files_)), dirs(std::move(dirs_)), parent(std::move(parent_)),
+      name(std::move(name_)) {}
+
+std::vector<std::shared_ptr<VfsFile>> VectorVfsDirectory::GetFiles() const {
+    return files;
+}
+
+std::vector<std::shared_ptr<VfsDirectory>> VectorVfsDirectory::GetSubdirectories() const {
+    return dirs;
+}
+
+bool VectorVfsDirectory::IsWritable() const {
+    return false;
+}
+
+bool VectorVfsDirectory::IsReadable() const {
+    return true;
+}
+
+std::string VectorVfsDirectory::GetName() const {
+    return name;
+}
+
+std::shared_ptr<VfsDirectory> VectorVfsDirectory::GetParentDirectory() const {
+    return parent;
+}
+
+template <typename T>
+static bool FindAndRemoveVectorElement(std::vector<T>& vec, std::string_view name) {
+    const auto iter =
+        std::find_if(vec.begin(), vec.end(), [name](const T& e) { return e->GetName() == name; });
+    if (iter == vec.end())
+        return false;
+
+    vec.erase(iter);
+    return true;
+}
+
+bool VectorVfsDirectory::DeleteSubdirectory(std::string_view name) {
+    return FindAndRemoveVectorElement(dirs, name);
+}
+
+bool VectorVfsDirectory::DeleteFile(std::string_view name) {
+    return FindAndRemoveVectorElement(files, name);
+}
+
+bool VectorVfsDirectory::Rename(std::string_view name_) {
+    name = name_;
+    return true;
+}
+
+std::shared_ptr<VfsDirectory> VectorVfsDirectory::CreateSubdirectory(std::string_view name) {
+    return nullptr;
+}
+
+std::shared_ptr<VfsFile> VectorVfsDirectory::CreateFile(std::string_view name) {
+    return nullptr;
+}
+
+void VectorVfsDirectory::AddFile(VirtualFile file) {
+    files.push_back(std::move(file));
+}
+
+void VectorVfsDirectory::AddDirectory(VirtualDir dir) {
+    dirs.push_back(std::move(dir));
+}
+
+bool VectorVfsDirectory::ReplaceFileWithSubdirectory(VirtualFile file, VirtualDir dir) {
+    if (!DeleteFile(file->GetName()))
+        return false;
+    dirs.emplace_back(std::move(dir));
+    return true;
+}
+} // namespace FileSys
diff --git a/src/core/file_sys/vfs_vector.h b/src/core/file_sys/vfs_vector.h
new file mode 100644
index 000000000..ba469647b
--- /dev/null
+++ b/src/core/file_sys/vfs_vector.h
@@ -0,0 +1,44 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include "core/file_sys/vfs.h"
+
+namespace FileSys {
+
+// An implementation of VfsDirectory that maintains two vectors for subdirectories and files.
+// Vector data is supplied upon construction.
+struct VectorVfsDirectory : public VfsDirectory {
+    explicit VectorVfsDirectory(std::vector<VirtualFile> files = {},
+                                std::vector<VirtualDir> dirs = {}, VirtualDir parent = nullptr,
+                                std::string name = "");
+
+    std::vector<std::shared_ptr<VfsFile>> GetFiles() const override;
+    std::vector<std::shared_ptr<VfsDirectory>> GetSubdirectories() const override;
+    bool IsWritable() const override;
+    bool IsReadable() const override;
+    std::string GetName() const override;
+    std::shared_ptr<VfsDirectory> GetParentDirectory() const override;
+    bool DeleteSubdirectory(std::string_view name) override;
+    bool DeleteFile(std::string_view name) override;
+    bool Rename(std::string_view name) override;
+    std::shared_ptr<VfsDirectory> CreateSubdirectory(std::string_view name) override;
+    std::shared_ptr<VfsFile> CreateFile(std::string_view name) override;
+
+    virtual void AddFile(VirtualFile file);
+    virtual void AddDirectory(VirtualDir dir);
+
+protected:
+    bool ReplaceFileWithSubdirectory(VirtualFile file, VirtualDir dir) override;
+
+private:
+    std::vector<VirtualFile> files;
+    std::vector<VirtualDir> dirs;
+
+    VirtualDir parent;
+    std::string name;
+};
+
+} // namespace FileSys