libdexfile/dex/dex_file_verifier.h - platform/art - Git at Google

 /*
  * 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 "class_accessor.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 dex::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,
                                 ClassAccessor::Method* direct_method,
                                 size_t* remaining_directs);
   ALWAYS_INLINE
   bool CheckOrder(const char* type_descr, uint32_t curr_index, uint32_t prev_index);
   bool CheckStaticFieldTypes(const dex::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(size_t count,
                                      ClassAccessor::Field* field,
                                      bool* have_class,
                                      dex::TypeIndex* class_type_index,
                                      const dex::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.
   bool CheckIntraClassDataItemMethods(ClassAccessor::Method* method,
                                       size_t num_methods,
                                       ClassAccessor::Method* direct_method,
                                       size_t num_directs,
                                       bool* have_class,
                                       dex::TypeIndex* class_type_index,
                                       const dex::ClassDef** class_def);

   bool CheckIntraCodeItem();
   bool CheckIntraStringDataItem();
   bool CheckIntraDebugInfoItem();
   bool CheckIntraAnnotationItem();
   bool CheckIntraAnnotationsDirectoryItem();
   bool CheckIntraHiddenapiClassData();

   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 dex::FieldId* CheckLoadFieldId(uint32_t idx, const char* error_fmt);
   const dex::MethodId* CheckLoadMethodId(uint32_t idx, const char* error_fmt);
   const dex::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 dex::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(dex::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_
	/*
	* 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 "class_accessor.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 dex::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,
	ClassAccessor::Method* direct_method,
	size_t* remaining_directs);
	ALWAYS_INLINE
	bool CheckOrder(const char* type_descr, uint32_t curr_index, uint32_t prev_index);
	bool CheckStaticFieldTypes(const dex::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(size_t count,
	ClassAccessor::Field* field,
	bool* have_class,
	dex::TypeIndex* class_type_index,
	const dex::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.
	bool CheckIntraClassDataItemMethods(ClassAccessor::Method* method,
	size_t num_methods,
	ClassAccessor::Method* direct_method,
	size_t num_directs,
	bool* have_class,
	dex::TypeIndex* class_type_index,
	const dex::ClassDef** class_def);

	bool CheckIntraCodeItem();
	bool CheckIntraStringDataItem();
	bool CheckIntraDebugInfoItem();
	bool CheckIntraAnnotationItem();
	bool CheckIntraAnnotationsDirectoryItem();
	bool CheckIntraHiddenapiClassData();

	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 dex::FieldId* CheckLoadFieldId(uint32_t idx, const char* error_fmt);
	const dex::MethodId* CheckLoadMethodId(uint32_t idx, const char* error_fmt);
	const dex::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 dex::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(dex::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_