ams.mitm: provide different boot0-protection for custom public key

This commit is contained in:
Michael Scire 2020-11-10 23:25:24 -08:00
parent 80f567d46a
commit d8bd3d16bb
3 changed files with 206 additions and 24 deletions

View file

@ -33,10 +33,27 @@ namespace ams::mitm::fs {
constexpr const char AtmosphereHblWebContentDir[] = "/atmosphere/hbl_html/";
constexpr const char ProgramWebContentDir[] = "/manual_html/";
os::Mutex g_data_storage_lock(false);
os::Mutex g_storage_cache_lock(false);
constinit os::SdkMutex g_data_storage_lock;
constinit os::SdkMutex g_storage_cache_lock;
std::unordered_map<u64, std::weak_ptr<ams::fssrv::sf::IStorage>> g_storage_cache;
constinit os::SdkMutex g_boot0_detect_lock;
constinit bool g_detected_boot0_kind = false;
constinit bool g_is_boot0_custom_public_key = false;
bool IsBoot0CustomPublicKey(::FsStorage &storage) {
if (AMS_UNLIKELY(!g_detected_boot0_kind)) {
std::scoped_lock lk(g_boot0_detect_lock);
if (AMS_LIKELY(!g_detected_boot0_kind)) {
g_is_boot0_custom_public_key = DetectBoot0CustomPublicKey(storage);
g_detected_boot0_kind = true;
}
}
return g_is_boot0_custom_public_key;
}
std::shared_ptr<ams::fssrv::sf::IStorage> GetStorageCacheEntry(ncm::ProgramId program_id) {
std::scoped_lock lk(g_storage_cache_lock);
@ -275,7 +292,11 @@ namespace ams::mitm::fs {
/* Set output storage. */
if (bis_partition_id == FsBisPartitionId_BootPartition1Root) {
out.SetValue(MakeSharedStorage(new Boot0Storage(bis_storage, this->client_info)), target_object_id);
if (IsBoot0CustomPublicKey(bis_storage)) {
out.SetValue(MakeSharedStorage(new CustomPublicKeyBoot0Storage(bis_storage, this->client_info, spl::GetSocType())), target_object_id);
} else {
out.SetValue(MakeSharedStorage(new Boot0Storage(bis_storage, this->client_info)), target_object_id);
}
} else if (bis_partition_id == FsBisPartitionId_CalibrationBinary) {
out.SetValue(MakeSharedStorage(new CalibrationBinaryStorage(bis_storage, this->client_info)), target_object_id);
} else {

View file

@ -22,9 +22,36 @@ namespace ams::mitm::fs {
namespace {
os::Mutex g_boot0_access_mutex(false);
os::SdkMutex g_boot0_access_mutex;
constinit bool g_custom_public_key = false;
u8 g_boot0_bct_buffer[Boot0Storage::BctEndOffset];
/* Recognize special public key (https://gist.github.com/SciresM/16b63ac1d80494522bdba2c57995257c). */
/* P = 19 */
/* Q = 1696986749729493925354392349339746171297507422986462747526968361144447230710192316397327889522451749459854070558277878297255552508603806832852079596337539247651161831569525505882103311631577368514276343192042634740927726070847704397913856975832811679847928433261678072951551065705680482548543833651752439700272736498378724153330763357721354498194000536297732323628263256733931353143625854828275237159155585342783077681713929284136658773985266864804093157854331138230313706015557050002740810464618031715670281442110238274404626065924786185264268216336867948322976979393032640085259926883014490947373494538254895109731 */
/* N = 0xFF696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696969696959 */
/* E = 0x10001 */
/* D = 6512128715229088976470211610075969347035078304643231077895577077900787352712063823560162578441773733649014439616165727455431015055675770987914713980812453585413988983206576233689754710500864883529402371292948326392791238474661859182717295176679567362482790015587820446999760239570255254879359445627372805817473978644067558931078225451477635089763009580492462097185005355990612929951162366081631888011031830742459571000203341001926135389508196521518687349554188686396554248868403128728646457247197407637887195043486221295751496667162366700477934591694110831002874992896076061627516220934290742867397720103040314639313 */
constexpr const u8 CustomPublicKey[0x100] = {
0x59, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69,
0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69,
0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69,
0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69,
0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69,
0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69,
0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69,
0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69,
0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69,
0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69,
0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69,
0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69,
0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69,
0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69,
0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69,
0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0x69, 0xFF,
};
}
bool Boot0Storage::CanModifyBctPublicKey() {
@ -42,24 +69,22 @@ namespace ams::mitm::fs {
Result Boot0Storage::Read(s64 offset, void *_buffer, size_t size) {
std::scoped_lock lk{g_boot0_access_mutex};
AMS_ABORT_UNLESS(!g_custom_public_key);
/* Check if we have nothing to do. */
if (size == 0) {
return ResultSuccess();
}
R_SUCCEED_IF(size == 0);
return Base::Read(offset, _buffer, size);
}
Result Boot0Storage::Write(s64 offset, const void *_buffer, size_t size) {
std::scoped_lock lk{g_boot0_access_mutex};
AMS_ABORT_UNLESS(!g_custom_public_key);
const u8 *buffer = static_cast<const u8 *>(_buffer);
/* Check if we have nothing to do. */
if (size == 0) {
return ResultSuccess();
}
R_SUCCEED_IF(size == 0);
/* Protect the EKS region from writes. */
if (offset <= EksStart) {
@ -75,22 +100,18 @@ namespace ams::mitm::fs {
size = EksStart - offset;
}
} else if (offset < EksEnd) {
if (offset + size <= EksEnd) {
/* Ignore writes falling strictly within the region. */
return ResultSuccess();
} else {
/* Only write past the end of the region. */
const s64 diff = EksEnd - offset;
buffer += diff;
size -= diff;
offset = EksEnd;
}
/* Ignore writes falling strictly within the region. */
R_SUCCEED_IF(offset + size <= EksEnd);
/* Only write past the end of the region. */
const s64 diff = EksEnd - offset;
buffer += diff;
size -= diff;
offset = EksEnd;
}
/* If we have nothing to write, succeed immediately. */
if (size == 0) {
return ResultSuccess();
}
R_SUCCEED_IF(size == 0);
/* We want to protect AutoRCM from NS on ipatched units. If we can modify bct pubks or we're not touching any of them, proceed. */
if (this->CanModifyBctPublicKey() || offset >= BctEndOffset || (util::AlignUp(offset, BctSize) >= BctEndOffset && (offset % BctSize) >= BctPubkEnd)) {
@ -118,4 +139,129 @@ namespace ams::mitm::fs {
return Base::Write(0, g_boot0_bct_buffer, BctEndOffset);
}
CustomPublicKeyBoot0Storage::CustomPublicKeyBoot0Storage(FsStorage &s, const sm::MitmProcessInfo &c, spl::SocType soc) : Base(s), client_info(c), soc_type(soc) {
std::scoped_lock lk{g_boot0_access_mutex};
/* We're custom public key. */
g_custom_public_key = true;
}
Result CustomPublicKeyBoot0Storage::Read(s64 offset, void *_buffer, size_t size) {
std::scoped_lock lk{g_boot0_access_mutex};
AMS_ABORT_UNLESS(g_custom_public_key);
/* Check if we have nothing to do. */
R_SUCCEED_IF(size == 0);
u8 *buffer = static_cast<u8 *>(_buffer);
/* Check if we're reading the first BCTs for NS. */
/* If we are, we want to lie about the contents of BCT0/1 so that they validate. */
if (offset < 0x8000 && this->client_info.program_id == ncm::SystemProgramId::Ns) {
R_TRY(Base::Read(0, g_boot0_bct_buffer, Boot0Storage::BctEndOffset));
/* Determine the readable size. */
const size_t readable_bct01_size = std::min<size_t>(0x8000, offset + size) - offset;
std::memcpy(buffer, g_boot0_bct_buffer + 0x8000 + offset, readable_bct01_size);
/* Advance. */
buffer += readable_bct01_size;
offset += readable_bct01_size;
size -= readable_bct01_size;
}
/* Check if we have nothing to do. */
R_SUCCEED_IF(size == 0);
/* Perform whatever remains of the read. */
return Base::Read(offset, buffer, size);
}
Result CustomPublicKeyBoot0Storage::Write(s64 offset, const void *_buffer, size_t size) {
std::scoped_lock lk{g_boot0_access_mutex};
AMS_ABORT_UNLESS(g_custom_public_key);
const u8 *buffer = static_cast<const u8 *>(_buffer);
/* Check if we have nothing to do. */
R_SUCCEED_IF(size == 0);
/* Drop writes to the first BCTs. */
if (offset < 0x8000) {
/* Determine the writable size. */
const size_t writable_bct01_size = std::min<size_t>(0x8000, offset + size) - offset;
/* Advance. */
buffer += writable_bct01_size;
offset += writable_bct01_size;
size -= writable_bct01_size;
}
/* Check if we have nothing to do. */
R_SUCCEED_IF(size == 0);
/* Similarly, we want to drop writes to the end of boot0, where custom bootloader lives. */
R_SUCCEED_IF(offset >= 0x380000);
if (offset + size >= 0x380000) {
size = 0x380000 - offset;
}
/* On erista, we want to protect the EKS region. */
if (this->soc_type == spl::SocType_Erista) {
if (offset <= Boot0Storage::EksStart) {
if (offset + size < Boot0Storage::EksStart) {
/* Fall through, no need to do anything here. */
} else {
if (offset + size > Boot0Storage::EksEnd) {
/* Perform portion of write falling past end of keyblobs. */
const s64 diff = Boot0Storage::EksEnd - offset;
R_TRY(Base::Write(Boot0Storage::EksEnd, buffer + diff, size - diff));
}
/* Adjust size to avoid writing end of data. */
size = Boot0Storage::EksStart - offset;
}
} else if (offset < Boot0Storage::EksEnd) {
/* Ignore writes falling strictly within the region. */
R_SUCCEED_IF(offset + size <= Boot0Storage::EksEnd);
/* Only write past the end of the region. */
const s64 diff = Boot0Storage::EksEnd - offset;
buffer += diff;
size -= diff;
offset = Boot0Storage::EksEnd;
}
}
/* If we have nothing to write, succeed immediately. */
R_SUCCEED_IF(size == 0);
/* Perform whatever remains of the write. */
return Base::Write(offset, buffer, size);
}
bool DetectBoot0CustomPublicKey(::FsStorage &storage) {
/* Determine public key offset. */
const size_t bct_pubk_offset = spl::GetSocType() == spl::SocType_Mariko ? 0x10 : 0x210;
u8 work_buffer[0x400];
/* Read BCT-Normal-Main. */
R_ABORT_UNLESS(::fsStorageRead(std::addressof(storage), 0, work_buffer, sizeof(work_buffer)));
/* Check for custom public key. */
if (std::memcmp(work_buffer + bct_pubk_offset, CustomPublicKey, sizeof(CustomPublicKey)) != 0) {
return false;
}
/* Read BCT-Safe-Main. */
R_ABORT_UNLESS(::fsStorageRead(std::addressof(storage), 0x4000, work_buffer, sizeof(work_buffer)));
/* Check for custom public key. */
if (std::memcmp(work_buffer + bct_pubk_offset, CustomPublicKey, sizeof(CustomPublicKey)) != 0) {
return false;
}
return true;
}
}

View file

@ -140,10 +140,25 @@ namespace ams::mitm::fs {
private:
bool CanModifyBctPublicKey();
public:
Boot0Storage(FsStorage &s, const sm::MitmProcessInfo &c) : Base(s), client_info(c) { /* ... */ }
Boot0Storage(FsStorage &s, const sm::MitmProcessInfo &c) : Base(s), client_info(c) { /* ... */ }
public:
virtual Result Read(s64 offset, void *_buffer, size_t size) override;
virtual Result Write(s64 offset, const void *_buffer, size_t size) override;
};
class CustomPublicKeyBoot0Storage : public SectoredStorageAdapter<ams::fs::RemoteStorage, 0x200> {
public:
using Base = SectoredStorageAdapter<ams::fs::RemoteStorage, 0x200>;
private:
sm::MitmProcessInfo client_info;
spl::SocType soc_type;
public:
CustomPublicKeyBoot0Storage(FsStorage &s, const sm::MitmProcessInfo &c, spl::SocType soc);
public:
virtual Result Read(s64 offset, void *_buffer, size_t size) override;
virtual Result Write(s64 offset, const void *_buffer, size_t size) override;
};
bool DetectBoot0CustomPublicKey(::FsStorage &storage);
}