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/*
* Copyright (C) 2011 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.
*/
#ifndef ART_LIBDEXFILE_DEX_DEX_FILE_VERIFIER_H_
#define ART_LIBDEXFILE_DEX_DEX_FILE_VERIFIER_H_
#include <limits>
#include <unordered_set>
#include "base/hash_map.h"
#include "base/safe_map.h"
#include "dex_file.h"
#include "dex_file_types.h"
namespace art {
class DexFileVerifier {
public:
static bool Verify(const DexFile* dex_file,
const uint8_t* begin,
size_t size,
const char* location,
bool verify_checksum,
std::string* error_msg);
const std::string& FailureReason() const {
return failure_reason_;
}
private:
DexFileVerifier(const DexFile* dex_file,
const uint8_t* begin,
size_t size,
const char* location,
bool verify_checksum)
: dex_file_(dex_file),
begin_(begin),
size_(size),
location_(location),
verify_checksum_(verify_checksum),
header_(&dex_file->GetHeader()),
ptr_(nullptr),
previous_item_(nullptr),
angle_bracket_start_index_(std::numeric_limits<size_t>::max()),
angle_bracket_end_index_(std::numeric_limits<size_t>::max()),
angle_init_angle_index_(std::numeric_limits<size_t>::max()),
angle_clinit_angle_index_(std::numeric_limits<size_t>::max()) {
}
bool Verify();
bool CheckShortyDescriptorMatch(char shorty_char, const char* descriptor, bool is_return_type);
bool CheckListSize(const void* start, size_t count, size_t element_size, const char* label);
// Check a list. The head is assumed to be at *ptr, and elements to be of size element_size. If
// successful, the ptr will be moved forward the amount covered by the list.
bool CheckList(size_t element_size, const char* label, const uint8_t* *ptr);
// Checks whether the offset is zero (when size is zero) or that the offset falls within the area
// claimed by the file.
bool CheckValidOffsetAndSize(uint32_t offset, uint32_t size, size_t alignment, const char* label);
// Checks whether the size is less than the limit.
bool CheckSizeLimit(uint32_t size, uint32_t limit, const char* label);
bool CheckIndex(uint32_t field, uint32_t limit, const char* label);
bool CheckHeader();
bool CheckMap();
uint32_t ReadUnsignedLittleEndian(uint32_t size);
bool CheckAndGetHandlerOffsets(const DexFile::CodeItem* code_item,
uint32_t* handler_offsets, uint32_t handlers_size);
bool CheckClassDataItemField(uint32_t idx,
uint32_t access_flags,
uint32_t class_access_flags,
dex::TypeIndex class_type_index,
bool expect_static);
bool CheckClassDataItemMethod(uint32_t idx,
uint32_t access_flags,
uint32_t class_access_flags,
dex::TypeIndex class_type_index,
uint32_t code_offset,
ClassDataItemIterator* direct_it,
bool expect_direct);
ALWAYS_INLINE
bool CheckOrder(const char* type_descr, uint32_t curr_index, uint32_t prev_index);
bool CheckStaticFieldTypes(const DexFile::ClassDef* class_def);
bool CheckPadding(size_t offset, uint32_t aligned_offset, DexFile::MapItemType type);
bool CheckEncodedValue();
bool CheckEncodedArray();
bool CheckEncodedAnnotation();
bool CheckIntraClassDataItem();
// Check all fields of the given type from the given iterator. Load the class data from the first
// field, if necessary (and return it), or use the given values.
template <bool kStatic>
bool CheckIntraClassDataItemFields(ClassDataItemIterator* it,
bool* have_class,
dex::TypeIndex* class_type_index,
const DexFile::ClassDef** class_def);
// Check all methods of the given type from the given iterator. Load the class data from the first
// method, if necessary (and return it), or use the given values.
template <bool kDirect>
bool CheckIntraClassDataItemMethods(ClassDataItemIterator* it,
ClassDataItemIterator* direct_it,
bool* have_class,
dex::TypeIndex* class_type_index,
const DexFile::ClassDef** class_def);
bool CheckIntraCodeItem();
bool CheckIntraStringDataItem();
bool CheckIntraDebugInfoItem();
bool CheckIntraAnnotationItem();
bool CheckIntraAnnotationsDirectoryItem();
template <DexFile::MapItemType kType>
bool CheckIntraSectionIterate(size_t offset, uint32_t count);
template <DexFile::MapItemType kType>
bool CheckIntraIdSection(size_t offset, uint32_t count);
template <DexFile::MapItemType kType>
bool CheckIntraDataSection(size_t offset, uint32_t count);
bool CheckIntraSection();
bool CheckOffsetToTypeMap(size_t offset, uint16_t type);
// Note: as sometimes kDexNoIndex16, being 0xFFFF, is a valid return value, we need an
// additional out parameter to signal any errors loading an index.
dex::TypeIndex FindFirstClassDataDefiner(const uint8_t* ptr, bool* success);
dex::TypeIndex FindFirstAnnotationsDirectoryDefiner(const uint8_t* ptr, bool* success);
bool CheckInterStringIdItem();
bool CheckInterTypeIdItem();
bool CheckInterProtoIdItem();
bool CheckInterFieldIdItem();
bool CheckInterMethodIdItem();
bool CheckInterClassDefItem();
bool CheckInterCallSiteIdItem();
bool CheckInterMethodHandleItem();
bool CheckInterAnnotationSetRefList();
bool CheckInterAnnotationSetItem();
bool CheckInterClassDataItem();
bool CheckInterAnnotationsDirectoryItem();
bool CheckInterSectionIterate(size_t offset, uint32_t count, DexFile::MapItemType type);
bool CheckInterSection();
// Load a string by (type) index. Checks whether the index is in bounds, printing the error if
// not. If there is an error, null is returned.
const char* CheckLoadStringByIdx(dex::StringIndex idx, const char* error_fmt);
const char* CheckLoadStringByTypeIdx(dex::TypeIndex type_idx, const char* error_fmt);
// Load a field/method/proto Id by index. Checks whether the index is in bounds, printing the
// error if not. If there is an error, null is returned.
const DexFile::FieldId* CheckLoadFieldId(uint32_t idx, const char* error_fmt);
const DexFile::MethodId* CheckLoadMethodId(uint32_t idx, const char* error_fmt);
const DexFile::ProtoId* CheckLoadProtoId(dex::ProtoIndex idx, const char* error_fmt);
void ErrorStringPrintf(const char* fmt, ...)
__attribute__((__format__(__printf__, 2, 3))) COLD_ATTR;
bool FailureReasonIsSet() const { return failure_reason_.size() != 0; }
// Retrieve class index and class def from the given member. index is the member index, which is
// taken as either a field or a method index (as designated by is_field). The result, if the
// member and declaring class could be found, is stored in class_type_index and class_def.
// This is an expensive lookup, as we have to find the class def by type index, which is a
// linear search. The output values should thus be cached by the caller.
bool FindClassIndexAndDef(uint32_t index,
bool is_field,
dex::TypeIndex* class_type_index,
const DexFile::ClassDef** output_class_def);
// Check validity of the given access flags, interpreted for a field in the context of a class
// with the given second access flags.
bool CheckFieldAccessFlags(uint32_t idx,
uint32_t field_access_flags,
uint32_t class_access_flags,
std::string* error_message);
// Check validity of the given method and access flags, in the context of a class with the given
// second access flags.
bool CheckMethodAccessFlags(uint32_t method_index,
uint32_t method_access_flags,
uint32_t class_access_flags,
uint32_t constructor_flags_by_name,
bool has_code,
bool expect_direct,
std::string* error_message);
// Check validity of given method if it's a constructor or class initializer.
bool CheckConstructorProperties(uint32_t method_index, uint32_t constructor_flags);
void FindStringRangesForMethodNames();
const DexFile* const dex_file_;
const uint8_t* const begin_;
const size_t size_;
const char* const location_;
const bool verify_checksum_;
const DexFile::Header* const header_;
struct OffsetTypeMapEmptyFn {
// Make a hash map slot empty by making the offset 0. Offset 0 is a valid dex file offset that
// is in the offset of the dex file header. However, we only store data section items in the
// map, and these are after the header.
void MakeEmpty(std::pair<uint32_t, uint16_t>& pair) const {
pair.first = 0u;
}
// Check if a hash map slot is empty.
bool IsEmpty(const std::pair<uint32_t, uint16_t>& pair) const {
return pair.first == 0;
}
};
struct OffsetTypeMapHashCompareFn {
// Hash function for offset.
size_t operator()(const uint32_t key) const {
return key;
}
// std::equal function for offset.
bool operator()(const uint32_t a, const uint32_t b) const {
return a == b;
}
};
// Map from offset to dex file type, HashMap for performance reasons.
HashMap<uint32_t,
uint16_t,
OffsetTypeMapEmptyFn,
OffsetTypeMapHashCompareFn,
OffsetTypeMapHashCompareFn> offset_to_type_map_;
const uint8_t* ptr_;
const void* previous_item_;
std::string failure_reason_;
// Set of type ids for which there are ClassDef elements in the dex file.
std::unordered_set<decltype(DexFile::ClassDef::class_idx_)> defined_classes_;
// Cached string indices for "interesting" entries wrt/ method names. Will be populated by
// FindStringRangesForMethodNames (which is automatically called before verifying the
// classdataitem section).
//
// Strings starting with '<' are in the range
// [angle_bracket_start_index_,angle_bracket_end_index_).
// angle_init_angle_index_ and angle_clinit_angle_index_ denote the indices of "<init>" and
// angle_clinit_angle_index_, respectively. If any value is not found, the corresponding
// index will be larger than any valid string index for this dex file.
size_t angle_bracket_start_index_;
size_t angle_bracket_end_index_;
size_t angle_init_angle_index_;
size_t angle_clinit_angle_index_;
};
} // namespace art
#endif // ART_LIBDEXFILE_DEX_DEX_FILE_VERIFIER_H_