1 /*
2  * Copyright (C) 2021 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 #pragma once
18 
19 #include <optional>
20 #include <string>
21 #include <vector>
22 
23 #include <fs_avb/fs_avb_util.h>
24 
25 uint8_t HexDigitToByte(char c);
26 
27 bool HexToBytes(const std::string &hex, std::vector<uint8_t> *bytes);
28 
29 std::string BytesToHex(const std::vector<uint8_t> &bytes);
30 
31 // The abstract class of SHA algorithms.
32 class ShaHasher {
33  protected:
34   const uint32_t digest_size_;
35 
ShaHasher(uint32_t digest_size)36   ShaHasher(uint32_t digest_size) : digest_size_(digest_size) {}
37 
38  public:
~ShaHasher()39   virtual ~ShaHasher() {}
40 
GetDigestSize()41   uint32_t GetDigestSize() const { return digest_size_; }
42 
43   virtual bool CalculateDigest(const void *buffer, size_t size,
44                                const void *salt, uint32_t block_length,
45                                uint8_t *digest) const = 0;
46 };
47 
48 template <typename CTX_TYPE>
49 class ShaHasherImpl : public ShaHasher {
50  private:
51   typedef int (*InitFunc)(CTX_TYPE *);
52   typedef int (*UpdateFunc)(CTX_TYPE *sha, const void *data, size_t len);
53   typedef int (*FinalFunc)(uint8_t *md, CTX_TYPE *sha);
54 
55   const InitFunc init_func_;
56   const UpdateFunc update_func_;
57   const FinalFunc final_func_;
58 
59  public:
ShaHasherImpl(InitFunc init_func,UpdateFunc update_func,FinalFunc final_func,uint32_t digest_size)60   ShaHasherImpl(InitFunc init_func, UpdateFunc update_func,
61                 FinalFunc final_func, uint32_t digest_size)
62       : ShaHasher(digest_size),
63         init_func_(init_func),
64         update_func_(update_func),
65         final_func_(final_func) {}
66 
~ShaHasherImpl()67   ~ShaHasherImpl() {}
68 
CalculateDigest(const void * buffer,size_t size,const void * salt,uint32_t salt_length,uint8_t * digest)69   bool CalculateDigest(const void *buffer, size_t size, const void *salt,
70                        uint32_t salt_length, uint8_t *digest) const {
71     CTX_TYPE ctx;
72     if (init_func_(&ctx) != 1) {
73       return false;
74     }
75     if (update_func_(&ctx, salt, salt_length) != 1) {
76       return false;
77     }
78     if (update_func_(&ctx, buffer, size) != 1) {
79       return false;
80     }
81     if (final_func_(digest, &ctx) != 1) {
82       return false;
83     }
84     return true;
85   }
86 };
87 
88 // Creates a hasher with the parameters corresponding to the algorithm name.
89 std::unique_ptr<ShaHasher> CreateShaHasher(const std::string &algorithm);
90 
91 // Checks whether the public key is an official GSI key or not.
92 bool ValidatePublicKeyBlob(const std::string &key_blob_to_validate);
93 
94 uint32_t GetSdkLevel();
95 
96 uint32_t GetProductFirstApiLevel();
97 
98 uint32_t GetVendorApiLevel();
99 
100 // Return board API level on GRF devices.
101 // On non-GRF, this function will return std::nullopt.
102 std::optional<uint32_t> GetBoardApiLevel();
103 
104 bool IsReleasedAndroidVersion();
105 
106 bool IsAutomotiveDevice();
107 
108 bool IsTvDevice();
109 
110 bool IsGoDevice();
111