ScoopDroid/android_system_core
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Use distinct GateKeeper userids when running a GSI.

Browse source 
GateKeeper uses userids to key authentication data. This poses a problem
for GSIs, since both the GSI and the host image will be storing separate
authentication data for the same userids.

To account for this, we add a large offset (1000000) to GSI userids
before handing them off to the GateKeeper HAL. Note that
SyntheticPasswordManager uses a similar trick to store Weaver data in
GateKeeper (when a Weaver HAL is not available).

Bug: 123716647
Test: PIN authentication works after booting into a GSI
Change-Id: I714368919f8e46ff1931f350342f09fa09225a35
This commit is contained in:
David Anderson 2019-02-15 15:59:39 -08:00
parent 33f344cb36
commit 97400bd865
2 changed files with 25 additions and 4 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

1
gatekeeperd/Android.bp
View file

@ -31,6 +31,7 @@ cc_binary {
shared_libs: [
"libbinder",
"libgatekeeper",
"libgsi",
"liblog",
"libhardware",
"libbase",

28
gatekeeperd/gatekeeperd.cpp
View file

@ -26,6 +26,8 @@
#include <memory>
#include <android/security/keystore/IKeystoreService.h>
#include <android-base/logging.h>
#include <android-base/properties.h>
#include <binder/IPCThreadState.h>
#include <binder/IServiceManager.h>
#include <binder/PermissionCache.h>
@ -34,6 +36,7 @@
#include <hardware/hw_auth_token.h>
#include <keystore/keystore.h> // For error code
#include <keystore/keystore_return_types.h>
#include <libgsi/libgsi.h>
#include <log/log.h>
#include <utils/Log.h>
#include <utils/String16.h>
@ -59,6 +62,7 @@ public:
GateKeeperProxy() {
clear_state_if_needed_done = false;
hw_device = IGatekeeper::getService();
is_running_gsi = android::base::GetBoolProperty(android::gsi::kGsiBootedProp, false);
if (hw_device == nullptr) {
ALOGW("falling back to software GateKeeper");
@ -86,7 +90,7 @@ public:
return;
}
if (mark_cold_boot()) {
if (mark_cold_boot() && !is_running_gsi) {
ALOGI("cold boot: clearing state");
if (hw_device != nullptr) {
hw_device->deleteAllUsers([](const GatekeeperResponse &){});
@ -138,6 +142,18 @@ public:
}
}
// This should only be called on uids being passed to the GateKeeper HAL. It ensures that
// secure storage shared across a GSI image and a host image will not overlap.
uint32_t adjust_uid(uint32_t uid) {
static constexpr uint32_t kGsiOffset = 1000000;
CHECK(uid < kGsiOffset);
CHECK(hw_device != nullptr);
if (is_running_gsi) {
return uid + kGsiOffset;
}
return uid;
}
virtual int enroll(uint32_t uid,
const uint8_t *current_password_handle, uint32_t current_password_handle_length,
const uint8_t *current_password, uint32_t current_password_length,
@ -181,7 +197,8 @@ public:
newPwd.setToExternal(const_cast<uint8_t*>(desired_password),
desired_password_length);
Return<void> hwRes = hw_device->enroll(uid, curPwdHandle, curPwd, newPwd,
uint32_t hw_uid = adjust_uid(uid);
Return<void> hwRes = hw_device->enroll(hw_uid, curPwdHandle, curPwd, newPwd,
[&ret, enrolled_password_handle, enrolled_password_handle_length]
(const GatekeeperResponse &rsp) {
ret = static_cast<int>(rsp.code); // propagate errors
@ -266,13 +283,14 @@ public:
// handle version 0 does not have hardware backed flag, and thus cannot be upgraded to
// a HAL if there was none before
if (handle->version == 0 || handle->hardware_backed) {
uint32_t hw_uid = adjust_uid(uid);
android::hardware::hidl_vec<uint8_t> curPwdHandle;
curPwdHandle.setToExternal(const_cast<uint8_t*>(enrolled_password_handle),
enrolled_password_handle_length);
android::hardware::hidl_vec<uint8_t> enteredPwd;
enteredPwd.setToExternal(const_cast<uint8_t*>(provided_password),
provided_password_length);
Return<void> hwRes = hw_device->verify(uid, challenge, curPwdHandle, enteredPwd,
Return<void> hwRes = hw_device->verify(hw_uid, challenge, curPwdHandle, enteredPwd,
[&ret, request_reenroll, auth_token, auth_token_length]
(const GatekeeperResponse &rsp) {
ret = static_cast<int>(rsp.code); // propagate errors
@ -354,7 +372,8 @@ public:
clear_sid(uid);
if (hw_device != nullptr) {
hw_device->deleteUser(uid, [] (const GatekeeperResponse &){});
uint32_t hw_uid = adjust_uid(uid);
hw_device->deleteUser(hw_uid, [] (const GatekeeperResponse &){});
}
}
@ -394,6 +413,7 @@ private:
std::unique_ptr<SoftGateKeeperDevice> soft_device;
bool clear_state_if_needed_done;
bool is_running_gsi;
};
}// namespace android