[go: nahoru, domu]

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// Copyright 2020 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "crypto/chaps_support.h"
#include <dlfcn.h>
#include <secmod.h>
#include <secmodt.h>
#include <string_view>
#include "base/logging.h"
#include "base/memory/raw_ptr_exclusion.h"
#include "base/memory/stack_allocated.h"
#include "base/threading/scoped_blocking_call.h"
#include "crypto/scoped_nss_types.h"
#include "nss_util_internal.h"
namespace crypto {
namespace {
// Constants for loading the Chrome OS TPM-backed PKCS #11 library.
const char kChapsModuleName[] = "Chaps";
const char kChapsPath[] = "libchaps.so";
class ScopedChapsLoadFixup {
STACK_ALLOCATED();
public:
ScopedChapsLoadFixup();
~ScopedChapsLoadFixup();
private:
#if defined(COMPONENT_BUILD)
// This field stores a handle and is not a pointer to PA memory.
// Also, this class is always stack-allocated and visibility is limited.
// Hence no benefit from using raw_ptr<void>.
RAW_PTR_EXCLUSION void* chaps_handle_;
#endif
};
#if defined(COMPONENT_BUILD)
ScopedChapsLoadFixup::ScopedChapsLoadFixup() {
// HACK: libchaps links the system protobuf and there are symbol conflicts
// with the bundled copy. Load chaps with RTLD_DEEPBIND to workaround.
chaps_handle_ = dlopen(kChapsPath, RTLD_LOCAL | RTLD_NOW | RTLD_DEEPBIND);
}
ScopedChapsLoadFixup::~ScopedChapsLoadFixup() {
// LoadNSSModule() will have taken a 2nd reference.
if (chaps_handle_)
dlclose(chaps_handle_);
}
#else
ScopedChapsLoadFixup::ScopedChapsLoadFixup() = default;
ScopedChapsLoadFixup::~ScopedChapsLoadFixup() = default;
#endif // defined(COMPONENT_BUILD)
} // namespace
SECMODModule* LoadChaps() {
// NSS functions may reenter //net via extension hooks. If the reentered
// code needs to synchronously wait for a task to run but the thread pool in
// which that task must run doesn't have enough threads to schedule it, a
// deadlock occurs. To prevent that, the base::ScopedBlockingCall below
// increments the thread pool capacity for the duration of the TPM
// initialization.
base::ScopedBlockingCall scoped_blocking_call(FROM_HERE,
base::BlockingType::WILL_BLOCK);
ScopedChapsLoadFixup chaps_loader;
DVLOG(3) << "Loading chaps...";
return LoadNSSModule(
kChapsModuleName, kChapsPath,
// For more details on these parameters, see:
// https://developer.mozilla.org/en/PKCS11_Module_Specs
// slotFlags=[PublicCerts] -- Certificates and public keys can be
// read from this slot without requiring a call to C_Login.
// askpw=only -- Only authenticate to the token when necessary.
"NSS=\"slotParams=(0={slotFlags=[PublicCerts] askpw=only})\"");
}
ScopedPK11Slot GetChapsSlot(SECMODModule* chaps_module, CK_SLOT_ID slot_id) {
DCHECK(chaps_module);
// NSS functions may reenter //net via extension hooks. If the reentered
// code needs to synchronously wait for a task to run but the thread pool in
// which that task must run doesn't have enough threads to schedule it, a
// deadlock occurs. To prevent that, the base::ScopedBlockingCall below
// increments the thread pool capacity for the duration of the TPM
// initialization.
base::ScopedBlockingCall scoped_blocking_call(FROM_HERE,
base::BlockingType::WILL_BLOCK);
DVLOG(3) << "Poking chaps module.";
SECStatus rv = SECMOD_UpdateSlotList(chaps_module);
if (rv != SECSuccess)
LOG(ERROR) << "SECMOD_UpdateSlotList failed: " << PORT_GetError();
ScopedPK11Slot slot =
ScopedPK11Slot(SECMOD_LookupSlot(chaps_module->moduleID, slot_id));
if (!slot)
LOG(ERROR) << "TPM slot " << slot_id << " not found.";
return slot;
}
bool IsChapsModule(SECMODModule* pk11_module) {
return pk11_module && std::string_view(pk11_module->commonName) ==
std::string_view(kChapsModuleName);
}
bool IsSlotProvidedByChaps(PK11SlotInfo* slot) {
return slot && IsChapsModule(PK11_GetModule(slot));
}
} // namespace crypto