/*
* Copyright (C) 2018 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 "hidden_api_finder.h"
#include "dex/class_accessor-inl.h"
#include "dex/code_item_accessors-inl.h"
#include "dex/dex_instruction-inl.h"
#include "dex/dex_file.h"
#include "dex/method_reference.h"
#include "hidden_api.h"
#include "resolver.h"
#include "veridex.h"
#include <iostream>
namespace art {
void HiddenApiFinder::CheckMethod(uint32_t method_id,
VeridexResolver* resolver,
MethodReference ref) {
// Note: we always query whether a method is in a list, as the app
// might define blacklisted APIs (which won't be used at runtime).
std::string name = HiddenApi::GetApiMethodName(resolver->GetDexFile(), method_id);
if (hidden_api_.IsInAnyList(name)) {
method_locations_[name].push_back(ref);
}
}
void HiddenApiFinder::CheckField(uint32_t field_id,
VeridexResolver* resolver,
MethodReference ref) {
// Note: we always query whether a field is in a list, as the app
// might define blacklisted APIs (which won't be used at runtime).
std::string name = HiddenApi::GetApiFieldName(resolver->GetDexFile(), field_id);
if (hidden_api_.IsInAnyList(name)) {
field_locations_[name].push_back(ref);
}
}
void HiddenApiFinder::CollectAccesses(VeridexResolver* resolver) {
const DexFile& dex_file = resolver->GetDexFile();
// Look at all types referenced in this dex file. Any of these
// types can lead to being used through reflection.
for (uint32_t i = 0; i < dex_file.NumTypeIds(); ++i) {
std::string name(dex_file.StringByTypeIdx(dex::TypeIndex(i)));
if (hidden_api_.IsInAnyList(name)) {
classes_.insert(name);
}
}
// Note: we collect strings constants only referenced in code items as the string table
// contains other kind of strings (eg types).
for (ClassAccessor accessor : dex_file.GetClasses()) {
for (const ClassAccessor::Method& method : accessor.GetMethods()) {
for (const DexInstructionPcPair& inst : method.GetInstructions()) {
switch (inst->Opcode()) {
case Instruction::CONST_STRING: {
dex::StringIndex string_index(inst->VRegB_21c());
std::string name = std::string(dex_file.StringDataByIdx(string_index));
// Cheap filtering on the string literal. We know it cannot be a field/method/class
// if it contains a space.
if (name.find(' ') == std::string::npos) {
// Class names at the Java level are of the form x.y.z, but the list encodes
// them of the form Lx/y/z;. Inner classes have '$' for both Java level class
// names in strings, and hidden API lists.
std::string str = HiddenApi::ToInternalName(name);
// Note: we can query the lists directly, as HiddenApi added classes that own
// private methods and fields in them.
// We don't add class names to the `strings_` set as we know method/field names
// don't have '.' or '/'. All hidden API class names have a '/'.
if (hidden_api_.IsInAnyList(str)) {
classes_.insert(str);
} else if (hidden_api_.IsInAnyList(name)) {
// Could be something passed to JNI.
classes_.insert(name);
} else {
// We only keep track of the location for strings, as these will be the
// field/method names the user is interested in.
strings_.insert(name);
reflection_locations_[name].push_back(method.GetReference());
}
}
break;
}
case Instruction::INVOKE_DIRECT:
case Instruction::INVOKE_INTERFACE:
case Instruction::INVOKE_STATIC:
case Instruction::INVOKE_SUPER:
case Instruction::INVOKE_VIRTUAL: {
CheckMethod(inst->VRegB_35c(), resolver, method.GetReference());
break;
}
case Instruction::INVOKE_DIRECT_RANGE:
case Instruction::INVOKE_INTERFACE_RANGE:
case Instruction::INVOKE_STATIC_RANGE:
case Instruction::INVOKE_SUPER_RANGE:
case Instruction::INVOKE_VIRTUAL_RANGE: {
CheckMethod(inst->VRegB_3rc(), resolver, method.GetReference());
break;
}
case Instruction::IGET:
case Instruction::IGET_WIDE:
case Instruction::IGET_OBJECT:
case Instruction::IGET_BOOLEAN:
case Instruction::IGET_BYTE:
case Instruction::IGET_CHAR:
case Instruction::IGET_SHORT: {
CheckField(inst->VRegC_22c(), resolver, method.GetReference());
break;
}
case Instruction::IPUT:
case Instruction::IPUT_WIDE:
case Instruction::IPUT_OBJECT:
case Instruction::IPUT_BOOLEAN:
case Instruction::IPUT_BYTE:
case Instruction::IPUT_CHAR:
case Instruction::IPUT_SHORT: {
CheckField(inst->VRegC_22c(), resolver, method.GetReference());
break;
}
case Instruction::SGET:
case Instruction::SGET_WIDE:
case Instruction::SGET_OBJECT:
case Instruction::SGET_BOOLEAN:
case Instruction::SGET_BYTE:
case Instruction::SGET_CHAR:
case Instruction::SGET_SHORT: {
CheckField(inst->VRegB_21c(), resolver, method.GetReference());
break;
}
case Instruction::SPUT:
case Instruction::SPUT_WIDE:
case Instruction::SPUT_OBJECT:
case Instruction::SPUT_BOOLEAN:
case Instruction::SPUT_BYTE:
case Instruction::SPUT_CHAR:
case Instruction::SPUT_SHORT: {
CheckField(inst->VRegB_21c(), resolver, method.GetReference());
break;
}
default:
break;
}
}
}
}
}
void HiddenApiFinder::Run(const std::vector<std::unique_ptr<VeridexResolver>>& resolvers) {
for (const std::unique_ptr<VeridexResolver>& resolver : resolvers) {
CollectAccesses(resolver.get());
}
}
void HiddenApiFinder::Dump(std::ostream& os,
HiddenApiStats* stats,
bool dump_reflection) {
stats->linking_count = method_locations_.size() + field_locations_.size();
// Dump methods from hidden APIs linked against.
for (const std::pair<const std::string,
std::vector<MethodReference>>& pair : method_locations_) {
hiddenapi::ApiList api_list = hidden_api_.GetApiList(pair.first);
CHECK(api_list.IsValid());
stats->api_counts[api_list.GetIntValue()]++;
os << "#" << ++stats->count << ": Linking " << api_list << " " << pair.first << " use(s):";
os << std::endl;
HiddenApiFinder::DumpReferences(os, pair.second);
os << std::endl;
}
// Dump fields from hidden APIs linked against.
for (const std::pair<const std::string,
std::vector<MethodReference>>& pair : field_locations_) {
hiddenapi::ApiList api_list = hidden_api_.GetApiList(pair.first);
CHECK(api_list.IsValid());
stats->api_counts[api_list.GetIntValue()]++;
os << "#" << ++stats->count << ": Linking " << api_list << " " << pair.first << " use(s):";
os << std::endl;
HiddenApiFinder::DumpReferences(os, pair.second);
os << std::endl;
}
if (dump_reflection) {
// Dump potential reflection uses.
for (const std::string& cls : classes_) {
for (const std::string& name : strings_) {
std::string full_name = cls + "->" + name;
hiddenapi::ApiList api_list = hidden_api_.GetApiList(full_name);
if (api_list.IsValid()) {
stats->api_counts[api_list.GetIntValue()]++;
stats->reflection_count++;
os << "#" << ++stats->count << ": Reflection " << api_list << " " << full_name
<< " potential use(s):";
os << std::endl;
HiddenApiFinder::DumpReferences(os, reflection_locations_[name]);
os << std::endl;
}
}
}
}
}
void HiddenApiFinder::DumpReferences(std::ostream& os,
const std::vector<MethodReference>& references) {
static const char* kPrefix = " ";
// Count number of occurrences of each reference, to make the output clearer.
std::map<std::string, size_t> counts;
for (const MethodReference& ref : references) {
std::string ref_string = HiddenApi::GetApiMethodName(ref);
if (!counts.count(ref_string)) {
counts[ref_string] = 0;
}
counts[ref_string]++;
}
for (const std::pair<const std::string, size_t>& pair : counts) {
os << kPrefix << pair.first;
if (pair.second > 1) {
os << " (" << pair.second << " occurrences)";
}
os << std::endl;
}
}
} // namespace art