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 <string> 20 #include <vector> 21 22 #include <fs_avb/fs_avb_util.h> 23 24 uint8_t HexDigitToByte(char c); 25 26 bool HexToBytes(const std::string &hex, std::vector<uint8_t> *bytes); 27 28 // The abstract class of SHA algorithms. 29 class ShaHasher { 30 protected: 31 const uint32_t digest_size_; 32 ShaHasher(uint32_t digest_size)33 ShaHasher(uint32_t digest_size) : digest_size_(digest_size) {} 34 35 public: ~ShaHasher()36 virtual ~ShaHasher() {} 37 GetDigestSize()38 uint32_t GetDigestSize() const { return digest_size_; } 39 40 virtual bool CalculateDigest(const void *buffer, size_t size, 41 const void *salt, uint32_t block_length, 42 uint8_t *digest) const = 0; 43 }; 44 45 template <typename CTX_TYPE> 46 class ShaHasherImpl : public ShaHasher { 47 private: 48 typedef int (*InitFunc)(CTX_TYPE *); 49 typedef int (*UpdateFunc)(CTX_TYPE *sha, const void *data, size_t len); 50 typedef int (*FinalFunc)(uint8_t *md, CTX_TYPE *sha); 51 52 const InitFunc init_func_; 53 const UpdateFunc update_func_; 54 const FinalFunc final_func_; 55 56 public: ShaHasherImpl(InitFunc init_func,UpdateFunc update_func,FinalFunc final_func,uint32_t digest_size)57 ShaHasherImpl(InitFunc init_func, UpdateFunc update_func, 58 FinalFunc final_func, uint32_t digest_size) 59 : ShaHasher(digest_size), 60 init_func_(init_func), 61 update_func_(update_func), 62 final_func_(final_func) {} 63 ~ShaHasherImpl()64 ~ShaHasherImpl() {} 65 CalculateDigest(const void * buffer,size_t size,const void * salt,uint32_t salt_length,uint8_t * digest)66 bool CalculateDigest(const void *buffer, size_t size, const void *salt, 67 uint32_t salt_length, uint8_t *digest) const { 68 CTX_TYPE ctx; 69 if (init_func_(&ctx) != 1) { 70 return false; 71 } 72 if (update_func_(&ctx, salt, salt_length) != 1) { 73 return false; 74 } 75 if (update_func_(&ctx, buffer, size) != 1) { 76 return false; 77 } 78 if (final_func_(digest, &ctx) != 1) { 79 return false; 80 } 81 return true; 82 } 83 }; 84 85 // Creates a hasher with the parameters corresponding to the algorithm name. 86 std::unique_ptr<ShaHasher> CreateShaHasher(const std::string &algorithm); 87 88 // Checks whether the public key is an official GSI key or not. 89 bool ValidatePublicKeyBlob(const std::string &key_blob_to_validate); 90 91 uint32_t GetProductFirstApiLevel(); 92 93 uint32_t GetBoardApiLevel(); 94