platform_system_security/keystore/keystore_get.cpp
Janis Danisevskis c7a9fa29c1 Port to binderized keymaster HAL
This patch ports keystore to the HIDL based binderized keymaster HAL.
Keystore has no more dependencies on legacy keymaster headers, and
therefore data structures, constant declarations, or enums. All
keymaster related data structures and enums used by keystore are the
once defined by the HIDL based keymaster HAL definition.  In the process
of porting, keystore underwent some changes:

* Keystore got a new implementation of AuthorizationSet that is fully
  based on the new HIDL data structures. Key parameters are now either
  organised as AuthorizationSets or hidl_vec<KeyParameter>.  (Formerly,
  this was a mixture of keymaster's AuthorizationSet,
  std::vec<keymaster_key_param_t>, and keymaster_key_param_set_t.)  The
  former is used for memory management and provides algorithms for
  assembling, joining, and subtracting sets of parameters.  The latter
  is used as wire format for the HAL IPC; it can wrap the memory owned
  by an AuthorizationSet for this purpose.  The AuthorizationSet is
  accompanied by a new implementation of type safe functions for
  creating and accessing tagged key parameters,
  Authorizations (keystore/keymaster_tags.h).
* A new type (KSSReturnCode) was introduced that wraps keystore service
  response codes. Keystore has two sets of error codes.  ErrorCode
  errors are less than 0 and use 0 as success value.  ResponseCode
  errors are greater than zero and use 1 as success value.  This patch
  changes ResponseCode to be an enum class so that is no longer
  assignable to int without a cast. The new return type can only be
  initialized by ResponseCode or ErrorCode and when accessed as int32_t,
  which happens on serialization when the response is send to a client,
  the success values are coalesced onto 1 as expected by the
  clients. KSSreturnCode is also comparable to ResponseCode and
  ErrorCode, and the predicate isOk() returns true if it was initialized
  with either ErrorCode::OK (0) or ReponseCode::NO_ERROR (1).
* A bug was fixed, that caused the keystore verify function to return
  success, regardless of the input, internal errors, or lack of
  permissions.
* The marshalling code in IKeystoreService.cpp was rewritten.  For data
  structures that are known to keymaster, the client facing side of
  keystore uses HIDL based data structures as (target) source
  for (un)marshaling to avoid further conversion.  hidl_vecs are used to
  wrap parcel memory without copying and taking ownership where
  possible.
* Explicit use of malloc is reduced (malloc was required by the C nature
  of the old HAL).  The new implementations avoid explicit use of
  malloc/new and waive the use of pointers for return values. Instead,
  functions return by value objects that take ownership of secondary
  memory allocations where required.

Test: runtest --path=cts/tests/tests/keystore/src/android/keystore/cts

Bug: 32020919
Change-Id: I59d3a0f4a6bdf6bb3bbf791ad8827c463effa286
2017-01-23 08:30:49 -07:00

45 lines
1.4 KiB
C++

/*
* Copyright (C) 2012 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <keystore/IKeystoreService.h>
#include <binder/IServiceManager.h>
#include <keystore/keystore_get.h>
using namespace android;
using namespace keystore;
ssize_t keystore_get(const char *key, size_t keyLength, uint8_t** value) {
sp<IServiceManager> sm = defaultServiceManager();
sp<IBinder> binder = sm->getService(String16("android.security.keystore"));
sp<IKeystoreService> service = interface_cast<IKeystoreService>(binder);
if (service == NULL) {
return -1;
}
hidl_vec<uint8_t> result;
auto ret = service->get(String16(key, keyLength), -1, &result);
if (!ret.isOk()) return -1;
if (value) {
*value = reinterpret_cast<uint8_t*>(malloc(result.size()));
if (!*value) return -1;
memcpy(*value, &result[0], result.size());
}
return result.size();
}