1 // 2 // Copyright (C) 2018 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 UPDATE_ENGINE_PAYLOAD_CONSUMER_PAYLOAD_METADATA_H_ 18 #define UPDATE_ENGINE_PAYLOAD_CONSUMER_PAYLOAD_METADATA_H_ 19 20 #include <inttypes.h> 21 22 #include <string> 23 #include <vector> 24 25 #include <base/macros.h> 26 #include <brillo/secure_blob.h> 27 28 #include "update_engine/common/error_code.h" 29 #include "update_engine/common/platform_constants.h" 30 #include "update_engine/update_metadata.pb.h" 31 32 namespace chromeos_update_engine { 33 34 enum class MetadataParseResult { 35 kSuccess, 36 kError, 37 kInsufficientData, 38 }; 39 40 // This class parses payload metadata and validate its signature. 41 class PayloadMetadata { 42 public: 43 static const uint64_t kDeltaVersionOffset; 44 static const uint64_t kDeltaVersionSize; 45 static const uint64_t kDeltaManifestSizeOffset; 46 static const uint64_t kDeltaManifestSizeSize; 47 static const uint64_t kDeltaMetadataSignatureSizeSize; 48 49 PayloadMetadata() = default; 50 51 // Attempts to parse the update payload header starting from the beginning of 52 // |payload|. On success, returns kMetadataParseSuccess. Returns 53 // kMetadataParseInsufficientData if more data is needed to parse the complete 54 // metadata. Returns kMetadataParseError if the metadata can't be parsed given 55 // the payload. 56 MetadataParseResult ParsePayloadHeader(const brillo::Blob& payload, 57 ErrorCode* error); 58 // Simpler version of the above, returns true on success. 59 bool ParsePayloadHeader(const brillo::Blob& payload); 60 61 // Given the |payload|, verifies that the signed hash of its metadata matches 62 // |metadata_signature| (if present) or the metadata signature in payload 63 // itself (if present). Returns ErrorCode::kSuccess on match or a suitable 64 // error code otherwise. This method must be called before any part of the 65 // metadata is parsed so that a man-in-the-middle attack on the SSL connection 66 // to the payload server doesn't exploit any vulnerability in the code that 67 // parses the protocol buffer. 68 ErrorCode ValidateMetadataSignature(const brillo::Blob& payload, 69 const std::string& metadata_signature, 70 const std::string& pem_public_key) const; 71 72 // Returns the major payload version. If the version was not yet parsed, 73 // returns zero. GetMajorVersion()74 uint64_t GetMajorVersion() const { return major_payload_version_; } 75 76 // Returns the size of the payload metadata, which includes the payload header 77 // and the manifest. If the header was not yet parsed, returns zero. GetMetadataSize()78 uint64_t GetMetadataSize() const { return metadata_size_; } 79 80 // Returns the size of the payload metadata signature. If the header was not 81 // yet parsed, returns zero. GetMetadataSignatureSize()82 uint32_t GetMetadataSignatureSize() const { return metadata_signature_size_; } 83 84 // Set |*out_manifest| to the manifest in |payload|. 85 // Returns true on success. 86 bool GetManifest(const brillo::Blob& payload, 87 DeltaArchiveManifest* out_manifest) const; 88 89 private: 90 // Set |*out_offset| to the byte offset at which the manifest protobuf begins 91 // in a payload. Return true on success, false if the offset is unknown. 92 bool GetManifestOffset(uint64_t* out_offset) const; 93 94 // Set |*out_offset| to the byte offset where the size of the metadata 95 // signature is stored in a payload. Return true on success, if this field is 96 // not present in the payload, return false. 97 bool GetMetadataSignatureSizeOffset(uint64_t* out_offset) const; 98 99 uint64_t metadata_size_{0}; 100 uint64_t manifest_size_{0}; 101 uint32_t metadata_signature_size_{0}; 102 uint64_t major_payload_version_{0}; 103 104 DISALLOW_COPY_AND_ASSIGN(PayloadMetadata); 105 }; 106 107 } // namespace chromeos_update_engine 108 109 #endif // UPDATE_ENGINE_PAYLOAD_CONSUMER_PAYLOAD_METADATA_H_ 110