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Fix undefined 32-bit shift that traps on arm64 (daemon crashes on card read) #1256

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Fix undefined 32-bit shift that traps on arm64 (daemon crashes on card read) #1256

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9fed57c
daemon: fix undefined 32-bit shift that crashes native arm64 builds
hyperbotsx Jul 25, 2026
c4b93da
daemon: ignore errored HID input reports on macOS
hyperbotsx Jul 25, 2026
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6 changes: 5 additions & 1 deletion src/FilesCache.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -156,8 +156,12 @@ bool FilesCache::setCardCPZ(QByteArray cardCPZ)
m_filePath = dataDir.absoluteFilePath(fileName);

qint64 m_key = 0;
// The shift must stay 32-bit and wrap at 32 ((i*8) & 31) to derive the
// same key historical x86 builds produced: shifting a 32-bit value by
// >= 32 is undefined behaviour that x86 silently wrapped, while on
// arm64 the compiler turns it into a trap (crash on Apple Silicon).
for (int i = 0;i < std::min(8, static_cast<int>(cardCPZ.size()));i++)
m_key += (static_cast<unsigned int>(cardCPZ[i]) & 0xFF) << (i * 8);
m_key += (static_cast<unsigned int>(cardCPZ[i]) & 0xFF) << ((i * 8) & 31);

@limpkin limpkin Jul 27, 2026

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(unless I'm mistaken) and that's why AI isn't there yet: for the same input, this change will lead to different m_key outputs as nothing will be populated after the 32th bit.
https://github.com/mooltipass/minible/wiki/Mooltipass-Database-Model#-cpz-lookup-table


m_simpleCrypt.setKey(m_key);
m_simpleCrypt.setIntegrityProtectionMode(SimpleCrypt::ProtectionHash);
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6 changes: 5 additions & 1 deletion src/MPDevice.cpp
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Expand Up @@ -5414,9 +5414,13 @@ quint64 MPDevice::getUInt64EncryptionKey()
quint64 MPDevice::getUInt64EncryptionKeyOld()
{
qint64 key = 0;
// This legacy key derivation must reproduce what historical x86 builds
// computed: the 32-bit shift by >= 32 was undefined behaviour that x86
// silently wrapped ((i*8) & 31), while on arm64 the compiler turns the
// unmasked form into a trap (crash on Apple Silicon).
for (int i = 0; i < std::min(8, static_cast<int>(m_cardCPZ.size())) ; i++)
{
key += (static_cast<unsigned int>(m_cardCPZ[i]) & 0xFF) << (i*8);
key += (static_cast<unsigned int>(m_cardCPZ[i]) & 0xFF) << ((i*8) & 31);
}

return key;
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12 changes: 11 additions & 1 deletion src/MPDevice_mac.cpp
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Expand Up @@ -29,12 +29,22 @@ void _read_report_callback(void *context,
uint8_t *report,
CFIndex report_length)
{
Q_UNUSED(result);
Q_UNUSED(sender);
Q_UNUSED(report_type);
Q_UNUSED(report_id);

MPDevice_mac *dev = reinterpret_cast<MPDevice_mac *>(context);

// IOKit invokes this callback with an error result (and meaningless
// buffer/length) when the device drops mid-read, e.g. while the BLE
// device re-enumerates its interfaces. Never feed that to the parser.
if (result != kIOReturnSuccess || !report || report_length <= 0)
{
qWarning() << "Ignoring errored HID input report, result:" << result
<< "length:" << static_cast<qint64>(report_length);
return;
}

QByteArray data((const char *)report, report_length);
if (dev->isBT())
{
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