From f26fc64cb4f36fbc9be05ed153f32d8f4dd3850c Mon Sep 17 00:00:00 2001 From: Zach Hilman Date: Thu, 16 Aug 2018 17:12:05 -0400 Subject: [PATCH] key_manager: Add support for KEK and SD seed derivation --- src/core/crypto/key_manager.cpp | 114 +++++++++++++++++++++++++++++++- src/core/crypto/key_manager.h | 26 +++++++- 2 files changed, 135 insertions(+), 5 deletions(-) diff --git a/src/core/crypto/key_manager.cpp b/src/core/crypto/key_manager.cpp index 95158e630..e4b33f750 100644 --- a/src/core/crypto/key_manager.cpp +++ b/src/core/crypto/key_manager.cpp @@ -12,11 +12,105 @@ #include "common/file_util.h" #include "common/hex_util.h" #include "common/logging/log.h" +#include "core/crypto/aes_util.h" #include "core/crypto/key_manager.h" #include "core/settings.h" namespace Core::Crypto { +Key128 GenerateKeyEncryptionKey(Key128 source, Key128 master, Key128 kek_seed, Key128 key_seed) { + Key128 out{}; + + AESCipher cipher1(master, Mode::ECB); + cipher1.Transcode(kek_seed.data(), kek_seed.size(), out.data(), Op::Decrypt); + AESCipher cipher2(out, Mode::ECB); + cipher2.Transcode(source.data(), source.size(), out.data(), Op::Decrypt); + + if (key_seed != Key128{}) { + AESCipher cipher3(out, Mode::ECB); + cipher3.Transcode(key_seed.data(), key_seed.size(), out.data(), Op::Decrypt); + } + + return out; +} + +boost::optional DeriveSDSeed() { + const FileUtil::IOFile save_43(FileUtil::GetUserPath(FileUtil::UserPath::NANDDir) + + "/system/save/8000000000000043", + "rb+"); + if (!save_43.IsOpen()) + return boost::none; + const FileUtil::IOFile sd_private( + FileUtil::GetUserPath(FileUtil::UserPath::SDMCDir) + "/Nintendo/Contents/private", "rb+"); + if (!sd_private.IsOpen()) + return boost::none; + + sd_private.Seek(0, SEEK_SET); + std::array private_seed{}; + if (sd_private.ReadBytes(private_seed.data(), private_seed.size()) != 0x10) + return boost::none; + + std::array buffer{}; + size_t offset = 0; + for (; offset + 0x10 < save_43.GetSize(); ++offset) { + save_43.Seek(offset, SEEK_SET); + save_43.ReadBytes(buffer.data(), buffer.size()); + if (buffer == private_seed) + break; + } + + if (offset + 0x10 >= save_43.GetSize()) + return boost::none; + + Key128 seed{}; + save_43.Seek(offset + 0x10, SEEK_SET); + save_43.ReadBytes(seed.data(), seed.size()); + return seed; +} + +Loader::ResultStatus DeriveSDKeys(std::array& sd_keys, const KeyManager& keys) { + if (!keys.HasKey(S128KeyType::Source, static_cast(SourceKeyType::SDKEK))) + return Loader::ResultStatus::ErrorMissingSDKEKSource; + if (!keys.HasKey(S128KeyType::Source, static_cast(SourceKeyType::AESKEKGeneration))) + return Loader::ResultStatus::ErrorMissingAESKEKGenerationSource; + if (!keys.HasKey(S128KeyType::Source, static_cast(SourceKeyType::AESKeyGeneration))) + return Loader::ResultStatus::ErrorMissingAESKeyGenerationSource; + + const auto sd_kek_source = + keys.GetKey(S128KeyType::Source, static_cast(SourceKeyType::SDKEK)); + const auto aes_kek_gen = + keys.GetKey(S128KeyType::Source, static_cast(SourceKeyType::AESKEKGeneration)); + const auto aes_key_gen = + keys.GetKey(S128KeyType::Source, static_cast(SourceKeyType::AESKeyGeneration)); + const auto master_00 = keys.GetKey(S128KeyType::Master); + const auto sd_kek = + GenerateKeyEncryptionKey(sd_kek_source, master_00, aes_kek_gen, aes_key_gen); + + if (!keys.HasKey(S128KeyType::SDSeed)) + return Loader::ResultStatus::ErrorMissingSDSeed; + const auto sd_seed = keys.GetKey(S128KeyType::SDSeed); + + if (!keys.HasKey(S256KeyType::SDKeySource, static_cast(SDKeyType::Save))) + return Loader::ResultStatus::ErrorMissingSDSaveKeySource; + if (!keys.HasKey(S256KeyType::SDKeySource, static_cast(SDKeyType::NCA))) + return Loader::ResultStatus::ErrorMissingSDNCAKeySource; + + std::array sd_key_sources{ + keys.GetKey(S256KeyType::SDKeySource, static_cast(SDKeyType::Save)), + keys.GetKey(S256KeyType::SDKeySource, static_cast(SDKeyType::NCA)), + }; + + AESCipher cipher(sd_kek, Mode::ECB); + for (size_t i = 0; i < 2; ++i) { + for (size_t j = 0; j < 0x20; ++j) + sd_key_sources[i][j] ^= sd_seed[j & 0xF]; + cipher.Transcode(sd_key_sources[i].data(), sd_key_sources[i].size(), sd_keys[i].data(), + Op::Decrypt); + } + + return Loader::ResultStatus::Success; +} + KeyManager::KeyManager() { // Initialize keys const std::string hactool_keys_dir = FileUtil::GetHactoolConfigurationPath(); @@ -24,12 +118,15 @@ KeyManager::KeyManager() { if (Settings::values.use_dev_keys) { dev_mode = true; AttemptLoadKeyFile(yuzu_keys_dir, hactool_keys_dir, "dev.keys", false); + AttemptLoadKeyFile(yuzu_keys_dir, yuzu_keys_dir, "dev.keys_autogenerated", false); } else { dev_mode = false; AttemptLoadKeyFile(yuzu_keys_dir, hactool_keys_dir, "prod.keys", false); + AttemptLoadKeyFile(yuzu_keys_dir, yuzu_keys_dir, "prod.keys_autogenerated", false); } AttemptLoadKeyFile(yuzu_keys_dir, hactool_keys_dir, "title.keys", true); + AttemptLoadKeyFile(yuzu_keys_dir, yuzu_keys_dir, "title.keys_autogenerated", false); } void KeyManager::LoadFromFile(const std::string& filename, bool is_title_keys) { @@ -126,6 +223,13 @@ bool KeyManager::KeyFileExists(bool title) { } void KeyManager::DeriveSDSeedLazy() { + if (!HasKey(S128KeyType::SDSeed)) { + const auto res = DeriveSDSeed(); + if (res != boost::none) + SetKey(S128KeyType::SDSeed, res.get()); + } +} + const boost::container::flat_map> KeyManager::s128_file_id = { {"master_key_00", {S128KeyType::Master, 0, 0}}, {"master_key_01", {S128KeyType::Master, 1, 0}}, @@ -168,11 +272,17 @@ const boost::container::flat_map> KeyManager: {"key_area_key_system_02", {S128KeyType::KeyArea, 2, static_cast(KeyAreaKeyType::System)}}, {"key_area_key_system_03", {S128KeyType::KeyArea, 3, static_cast(KeyAreaKeyType::System)}}, {"key_area_key_system_04", {S128KeyType::KeyArea, 4, static_cast(KeyAreaKeyType::System)}}, + {"sd_card_kek_source", {S128KeyType::Source, static_cast(SourceKeyType::SDKEK), 0}}, + {"aes_kek_generation_source", + {S128KeyType::Source, static_cast(SourceKeyType::AESKEKGeneration), 0}}, + {"aes_key_generation_source", + {S128KeyType::Source, static_cast(SourceKeyType::AESKeyGeneration), 0}}, + {"sd_seed", {S128KeyType::SDSeed, 0, 0}}, }; const boost::container::flat_map> KeyManager::s256_file_id = { {"header_key", {S256KeyType::Header, 0, 0}}, - {"sd_card_save_key", {S256KeyType::SDSave, 0, 0}}, - {"sd_card_nca_key", {S256KeyType::SDNCA, 0, 0}}, + {"sd_card_save_key_source", {S256KeyType::SDKeySource, static_cast(SDKeyType::Save), 0}}, + {"sd_card_nca_key_source", {S256KeyType::SDKeySource, static_cast(SDKeyType::NCA), 0}}, }; } // namespace Core::Crypto diff --git a/src/core/crypto/key_manager.h b/src/core/crypto/key_manager.h index 33b1ad383..31040dc55 100644 --- a/src/core/crypto/key_manager.h +++ b/src/core/crypto/key_manager.h @@ -23,9 +23,8 @@ static_assert(sizeof(Key128) == 16, "Key128 must be 128 bytes big."); static_assert(sizeof(Key256) == 32, "Key128 must be 128 bytes big."); enum class S256KeyType : u64 { - Header, // - SDSave, // - SDNCA, // + Header, // + SDKeySource, // f1=SDKeyType }; enum class S128KeyType : u64 { @@ -37,6 +36,7 @@ enum class S128KeyType : u64 { KeyArea, // f1=crypto revision f2=type {app, ocean, system} SDSeed, // Titlekey, // f1=rights id LSB f2=rights id MSB + Source, // f1=source type, f2= sub id }; enum class KeyAreaKeyType : u8 { @@ -45,6 +45,17 @@ enum class KeyAreaKeyType : u8 { System, }; +enum class SourceKeyType : u8 { + SDKEK, + AESKEKGeneration, + AESKeyGeneration, +}; + +enum class SDKeyType : u8 { + Save, + NCA, +}; + template struct KeyIndex { KeyType type; @@ -83,6 +94,10 @@ public: static bool KeyFileExists(bool title); + // Call before using the sd seed to attempt to derive it if it dosen't exist. Needs system save + // 8*43 and the private file to exist. + void DeriveSDSeedLazy(); + private: boost::container::flat_map, Key128> s128_keys; boost::container::flat_map, Key256> s256_keys; @@ -95,4 +110,9 @@ private: static const boost::container::flat_map> s128_file_id; static const boost::container::flat_map> s256_file_id; }; + +Key128 GenerateKeyEncryptionKey(Key128 source, Key128 master, Key128 kek_seed, Key128 key_seed); +boost::optional DeriveSDSeed(); +Loader::ResultStatus DeriveSDKeys(std::array& sd_keys, const KeyManager& keys); + } // namespace Core::Crypto