1 /*
2  * Copyright (C) 2011 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef ART_RUNTIME_DEX_FILE_VERIFIER_H_
18 #define ART_RUNTIME_DEX_FILE_VERIFIER_H_
19 
20 #include <unordered_set>
21 
22 #include "dex_file.h"
23 #include "safe_map.h"
24 
25 namespace art {
26 
27 class DexFileVerifier {
28  public:
29   static bool Verify(const DexFile* dex_file, const uint8_t* begin, size_t size,
30                      const char* location, std::string* error_msg);
31 
FailureReason()32   const std::string& FailureReason() const {
33     return failure_reason_;
34   }
35 
36  private:
DexFileVerifier(const DexFile * dex_file,const uint8_t * begin,size_t size,const char * location)37   DexFileVerifier(const DexFile* dex_file, const uint8_t* begin, size_t size, const char* location)
38       : dex_file_(dex_file), begin_(begin), size_(size), location_(location),
39         header_(&dex_file->GetHeader()), ptr_(nullptr), previous_item_(nullptr)  {
40   }
41 
42   bool Verify();
43 
44   bool CheckShortyDescriptorMatch(char shorty_char, const char* descriptor, bool is_return_type);
45   bool CheckListSize(const void* start, size_t count, size_t element_size, const char* label);
46   // Check a list. The head is assumed to be at *ptr, and elements to be of size element_size. If
47   // successful, the ptr will be moved forward the amount covered by the list.
48   bool CheckList(size_t element_size, const char* label, const uint8_t* *ptr);
49   // Checks whether the offset is zero (when size is zero) or that the offset falls within the area
50   // claimed by the file.
51   bool CheckValidOffsetAndSize(uint32_t offset, uint32_t size, const char* label);
52   bool CheckIndex(uint32_t field, uint32_t limit, const char* label);
53 
54   bool CheckHeader();
55   bool CheckMap();
56 
57   uint32_t ReadUnsignedLittleEndian(uint32_t size);
58   bool CheckAndGetHandlerOffsets(const DexFile::CodeItem* code_item,
59                                  uint32_t* handler_offsets, uint32_t handlers_size);
60   bool CheckClassDataItemField(uint32_t idx, uint32_t access_flags, bool expect_static);
61   bool CheckClassDataItemMethod(uint32_t idx, uint32_t access_flags, uint32_t code_offset,
62                                 bool expect_direct);
63   bool CheckPadding(size_t offset, uint32_t aligned_offset);
64   bool CheckEncodedValue();
65   bool CheckEncodedArray();
66   bool CheckEncodedAnnotation();
67 
68   bool CheckIntraClassDataItem();
69   bool CheckIntraCodeItem();
70   bool CheckIntraStringDataItem();
71   bool CheckIntraDebugInfoItem();
72   bool CheckIntraAnnotationItem();
73   bool CheckIntraAnnotationsDirectoryItem();
74 
75   bool CheckIntraSectionIterate(size_t offset, uint32_t count, uint16_t type);
76   bool CheckIntraIdSection(size_t offset, uint32_t count, uint16_t type);
77   bool CheckIntraDataSection(size_t offset, uint32_t count, uint16_t type);
78   bool CheckIntraSection();
79 
80   bool CheckOffsetToTypeMap(size_t offset, uint16_t type);
81 
82   // Note: as sometimes kDexNoIndex16, being 0xFFFF, is a valid return value, we need an
83   // additional out parameter to signal any errors loading an index.
84   uint16_t FindFirstClassDataDefiner(const uint8_t* ptr, bool* success);
85   uint16_t FindFirstAnnotationsDirectoryDefiner(const uint8_t* ptr, bool* success);
86 
87   bool CheckInterStringIdItem();
88   bool CheckInterTypeIdItem();
89   bool CheckInterProtoIdItem();
90   bool CheckInterFieldIdItem();
91   bool CheckInterMethodIdItem();
92   bool CheckInterClassDefItem();
93   bool CheckInterAnnotationSetRefList();
94   bool CheckInterAnnotationSetItem();
95   bool CheckInterClassDataItem();
96   bool CheckInterAnnotationsDirectoryItem();
97 
98   bool CheckInterSectionIterate(size_t offset, uint32_t count, uint16_t type);
99   bool CheckInterSection();
100 
101   // Load a string by (type) index. Checks whether the index is in bounds, printing the error if
102   // not. If there is an error, null is returned.
103   const char* CheckLoadStringByIdx(uint32_t idx, const char* error_fmt);
104   const char* CheckLoadStringByTypeIdx(uint32_t type_idx, const char* error_fmt);
105 
106   // Load a field/method Id by index. Checks whether the index is in bounds, printing the error if
107   // not. If there is an error, null is returned.
108   const DexFile::FieldId* CheckLoadFieldId(uint32_t idx, const char* error_fmt);
109   const DexFile::MethodId* CheckLoadMethodId(uint32_t idx, const char* error_fmt);
110 
111   void ErrorStringPrintf(const char* fmt, ...)
112       __attribute__((__format__(__printf__, 2, 3))) COLD_ATTR;
113 
114   const DexFile* const dex_file_;
115   const uint8_t* const begin_;
116   const size_t size_;
117   const char* const location_;
118   const DexFile::Header* const header_;
119 
120   AllocationTrackingSafeMap<uint32_t, uint16_t, kAllocatorTagDexFileVerifier> offset_to_type_map_;
121   const uint8_t* ptr_;
122   const void* previous_item_;
123 
124   std::string failure_reason_;
125 
126   // Set of type ids for which there are ClassDef elements in the dex file.
127   std::unordered_set<decltype(DexFile::ClassDef::class_idx_)> defined_classes_;
128 };
129 
130 }  // namespace art
131 
132 #endif  // ART_RUNTIME_DEX_FILE_VERIFIER_H_
133