/* * Copyright (C) 2008 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. */ /* * Read-only access to Zip archives, with minimal heap allocation. */ #define LOG_TAG "ziparchive" #include "ziparchive/zip_archive.h" #include #include #include #include #include #include #include #include #include #include #include #if defined(__APPLE__) #define lseek64 lseek #endif #if defined(__BIONIC__) #include #endif #include #include #include // TEMP_FAILURE_RETRY may or may not be in unistd #include #include #include #include #include #include "zlib.h" #include "entry_name_utils-inl.h" #include "zip_archive_common.h" #include "zip_archive_private.h" // Used to turn on crc checks - verify that the content CRC matches the values // specified in the local file header and the central directory. static constexpr bool kCrcChecksEnabled = false; // The maximum number of bytes to scan backwards for the EOCD start. static const uint32_t kMaxEOCDSearch = kMaxCommentLen + sizeof(EocdRecord); // Set a reasonable cap (256 GiB) for the zip file size. So the data is always valid when // we parse the fields in cd or local headers as 64 bits signed integers. static constexpr uint64_t kMaxFileLength = 256 * static_cast(1u << 30u); /* * A Read-only Zip archive. * * We want "open" and "find entry by name" to be fast operations, and * we want to use as little memory as possible. We memory-map the zip * central directory, and load a hash table with pointers to the filenames * (which aren't null-terminated). The other fields are at a fixed offset * from the filename, so we don't need to extract those (but we do need * to byte-read and endian-swap them every time we want them). * * It's possible that somebody has handed us a massive (~1GB) zip archive, * so we can't expect to mmap the entire file. * * To speed comparisons when doing a lookup by name, we could make the mapping * "private" (copy-on-write) and null-terminate the filenames after verifying * the record structure. However, this requires a private mapping of * every page that the Central Directory touches. Easier to tuck a copy * of the string length into the hash table entry. */ #if defined(__BIONIC__) uint64_t GetOwnerTag(const ZipArchive* archive) { return android_fdsan_create_owner_tag(ANDROID_FDSAN_OWNER_TYPE_ZIPARCHIVE, reinterpret_cast(archive)); } #endif ZipArchive::ZipArchive(MappedZipFile&& map, bool assume_ownership) : mapped_zip(map), close_file(assume_ownership), directory_offset(0), central_directory(), directory_map(), num_entries(0) { #if defined(__BIONIC__) if (assume_ownership) { CHECK(mapped_zip.HasFd()); android_fdsan_exchange_owner_tag(mapped_zip.GetFileDescriptor(), 0, GetOwnerTag(this)); } #endif } ZipArchive::ZipArchive(const void* address, size_t length) : mapped_zip(address, length), close_file(false), directory_offset(0), central_directory(), directory_map(), num_entries(0) {} ZipArchive::~ZipArchive() { if (close_file && mapped_zip.GetFileDescriptor() >= 0) { #if defined(__BIONIC__) android_fdsan_close_with_tag(mapped_zip.GetFileDescriptor(), GetOwnerTag(this)); #else close(mapped_zip.GetFileDescriptor()); #endif } } struct CentralDirectoryInfo { uint64_t num_records; // The size of the central directory (in bytes). uint64_t cd_size; // The offset of the start of the central directory, relative // to the start of the file. uint64_t cd_start_offset; }; // Reads |T| at |readPtr| and increments |readPtr|. Returns std::nullopt if the boundary check // fails. template static std::optional TryConsumeUnaligned(uint8_t** readPtr, const uint8_t* bufStart, size_t bufSize) { if (bufSize < sizeof(T) || *readPtr - bufStart > bufSize - sizeof(T)) { ALOGW("Zip: %zu byte read exceeds the boundary of allocated buf, offset %zu, bufSize %zu", sizeof(T), *readPtr - bufStart, bufSize); return std::nullopt; } return ConsumeUnaligned(readPtr); } static ZipError FindCentralDirectoryInfoForZip64(const char* debugFileName, ZipArchive* archive, off64_t eocdOffset, CentralDirectoryInfo* cdInfo) { if (eocdOffset <= sizeof(Zip64EocdLocator)) { ALOGW("Zip: %s: Not enough space for zip64 eocd locator", debugFileName); return kInvalidFile; } // We expect to find the zip64 eocd locator immediately before the zip eocd. const int64_t locatorOffset = eocdOffset - sizeof(Zip64EocdLocator); Zip64EocdLocator zip64EocdLocator{}; if (!archive->mapped_zip.ReadAtOffset(reinterpret_cast((&zip64EocdLocator)), sizeof(Zip64EocdLocator), locatorOffset)) { ALOGW("Zip: %s: Read %zu from offset %" PRId64 " failed %s", debugFileName, sizeof(Zip64EocdLocator), locatorOffset, debugFileName); return kIoError; } if (zip64EocdLocator.locator_signature != Zip64EocdLocator::kSignature) { ALOGW("Zip: %s: Zip64 eocd locator signature not found at offset %" PRId64, debugFileName, locatorOffset); return kInvalidFile; } const int64_t zip64EocdOffset = zip64EocdLocator.zip64_eocd_offset; if (locatorOffset <= sizeof(Zip64EocdRecord) || zip64EocdOffset > locatorOffset - sizeof(Zip64EocdRecord)) { ALOGW("Zip: %s: Bad zip64 eocd offset %" PRId64 ", eocd locator offset %" PRId64, debugFileName, zip64EocdOffset, locatorOffset); return kInvalidOffset; } Zip64EocdRecord zip64EocdRecord{}; if (!archive->mapped_zip.ReadAtOffset(reinterpret_cast(&zip64EocdRecord), sizeof(Zip64EocdRecord), zip64EocdOffset)) { ALOGW("Zip: %s: read %zu from offset %" PRId64 " failed %s", debugFileName, sizeof(Zip64EocdLocator), zip64EocdOffset, debugFileName); return kIoError; } if (zip64EocdRecord.record_signature != Zip64EocdRecord::kSignature) { ALOGW("Zip: %s: Zip64 eocd record signature not found at offset %" PRId64, debugFileName, zip64EocdOffset); return kInvalidFile; } if (zip64EocdOffset <= zip64EocdRecord.cd_size || zip64EocdRecord.cd_start_offset > zip64EocdOffset - zip64EocdRecord.cd_size) { ALOGW("Zip: %s: Bad offset for zip64 central directory. cd offset %" PRIu64 ", cd size %" PRIu64 ", zip64 eocd offset %" PRIu64, debugFileName, zip64EocdRecord.cd_start_offset, zip64EocdRecord.cd_size, zip64EocdOffset); return kInvalidOffset; } *cdInfo = {.num_records = zip64EocdRecord.num_records, .cd_size = zip64EocdRecord.cd_size, .cd_start_offset = zip64EocdRecord.cd_start_offset}; return kSuccess; } static ZipError FindCentralDirectoryInfo(const char* debug_file_name, ZipArchive* archive, off64_t file_length, uint32_t read_amount, CentralDirectoryInfo* cdInfo) { std::vector scan_buffer(read_amount); const off64_t search_start = file_length - read_amount; if (!archive->mapped_zip.ReadAtOffset(scan_buffer.data(), read_amount, search_start)) { ALOGE("Zip: read %" PRId64 " from offset %" PRId64 " failed", static_cast(read_amount), static_cast(search_start)); return kIoError; } /* * Scan backward for the EOCD magic. In an archive without a trailing * comment, we'll find it on the first try. (We may want to consider * doing an initial minimal read; if we don't find it, retry with a * second read as above.) */ CHECK_LE(read_amount, std::numeric_limits::max()); int32_t i = read_amount - sizeof(EocdRecord); for (; i >= 0; i--) { if (scan_buffer[i] == 0x50) { uint32_t* sig_addr = reinterpret_cast(&scan_buffer[i]); if (android::base::get_unaligned(sig_addr) == EocdRecord::kSignature) { ALOGV("+++ Found EOCD at buf+%d", i); break; } } } if (i < 0) { ALOGD("Zip: EOCD not found, %s is not zip", debug_file_name); return kInvalidFile; } const off64_t eocd_offset = search_start + i; auto eocd = reinterpret_cast(scan_buffer.data() + i); /* * Verify that there's no trailing space at the end of the central directory * and its comment. */ const off64_t calculated_length = eocd_offset + sizeof(EocdRecord) + eocd->comment_length; if (calculated_length != file_length) { ALOGW("Zip: %" PRId64 " extraneous bytes at the end of the central directory", static_cast(file_length - calculated_length)); return kInvalidFile; } // One of the field is 0xFFFFFFFF, look for the zip64 EOCD instead. if (eocd->cd_size == UINT32_MAX || eocd->cd_start_offset == UINT32_MAX) { ALOGV("Looking for the zip64 EOCD, cd_size: %" PRIu32 "cd_start_offset: %" PRId32, eocd->cd_size, eocd->cd_start_offset); return FindCentralDirectoryInfoForZip64(debug_file_name, archive, eocd_offset, cdInfo); } /* * Grab the CD offset and size, and the number of entries in the * archive and verify that they look reasonable. */ if (static_cast(eocd->cd_start_offset) + eocd->cd_size > eocd_offset) { ALOGW("Zip: bad offsets (dir %" PRIu32 ", size %" PRIu32 ", eocd %" PRId64 ")", eocd->cd_start_offset, eocd->cd_size, static_cast(eocd_offset)); return kInvalidOffset; } *cdInfo = {.num_records = eocd->num_records, .cd_size = eocd->cd_size, .cd_start_offset = eocd->cd_start_offset}; return kSuccess; } /* * Find the zip Central Directory and memory-map it. * * On success, returns kSuccess after populating fields from the EOCD area: * directory_offset * directory_ptr * num_entries */ static ZipError MapCentralDirectory(const char* debug_file_name, ZipArchive* archive) { // Test file length. We use lseek64 to make sure the file is small enough to be a zip file. off64_t file_length = archive->mapped_zip.GetFileLength(); if (file_length == -1) { return kInvalidFile; } if (file_length > kMaxFileLength) { ALOGV("Zip: zip file too long %" PRId64, static_cast(file_length)); return kInvalidFile; } if (file_length < static_cast(sizeof(EocdRecord))) { ALOGV("Zip: length %" PRId64 " is too small to be zip", static_cast(file_length)); return kInvalidFile; } /* * Perform the traditional EOCD snipe hunt. * * We're searching for the End of Central Directory magic number, * which appears at the start of the EOCD block. It's followed by * 18 bytes of EOCD stuff and up to 64KB of archive comment. We * need to read the last part of the file into a buffer, dig through * it to find the magic number, parse some values out, and use those * to determine the extent of the CD. * * We start by pulling in the last part of the file. */ uint32_t read_amount = kMaxEOCDSearch; if (file_length < read_amount) { read_amount = static_cast(file_length); } CentralDirectoryInfo cdInfo = {}; if (auto result = FindCentralDirectoryInfo(debug_file_name, archive, file_length, read_amount, &cdInfo); result != kSuccess) { return result; } if (cdInfo.num_records == 0) { #if defined(__ANDROID__) ALOGW("Zip: empty archive?"); #endif return kEmptyArchive; } if (cdInfo.cd_size >= SIZE_MAX) { ALOGW("Zip: The size of central directory doesn't fit in range of size_t: %" PRIu64, cdInfo.cd_size); return kInvalidFile; } ALOGV("+++ num_entries=%" PRIu64 " dir_size=%" PRIu64 " dir_offset=%" PRIu64, cdInfo.num_records, cdInfo.cd_size, cdInfo.cd_start_offset); // It all looks good. Create a mapping for the CD, and set the fields in archive. if (!archive->InitializeCentralDirectory(static_cast(cdInfo.cd_start_offset), static_cast(cdInfo.cd_size))) { return kMmapFailed; } archive->num_entries = cdInfo.num_records; archive->directory_offset = cdInfo.cd_start_offset; return kSuccess; } static ZipError ParseZip64ExtendedInfoInExtraField( const uint8_t* extraFieldStart, uint16_t extraFieldLength, uint32_t zip32UncompressedSize, uint32_t zip32CompressedSize, std::optional zip32LocalFileHeaderOffset, Zip64ExtendedInfo* zip64Info) { if (extraFieldLength <= 4) { ALOGW("Zip: Extra field isn't large enough to hold zip64 info, size %" PRIu16, extraFieldLength); return kInvalidFile; } // Each header MUST consist of: // Header ID - 2 bytes // Data Size - 2 bytes uint16_t offset = 0; while (offset < extraFieldLength - 4) { auto readPtr = const_cast(extraFieldStart + offset); auto headerId = ConsumeUnaligned(&readPtr); auto dataSize = ConsumeUnaligned(&readPtr); offset += 4; if (dataSize > extraFieldLength - offset) { ALOGW("Zip: Data size exceeds the boundary of extra field, data size %" PRIu16, dataSize); return kInvalidOffset; } // Skip the other types of extensible data fields. Details in // https://pkware.cachefly.net/webdocs/casestudies/APPNOTE.TXT section 4.5 if (headerId != Zip64ExtendedInfo::kHeaderId) { offset += dataSize; continue; } std::optional uncompressedFileSize; std::optional compressedFileSize; std::optional localHeaderOffset; if (zip32UncompressedSize == UINT32_MAX) { uncompressedFileSize = TryConsumeUnaligned(&readPtr, extraFieldStart, extraFieldLength); if (!uncompressedFileSize.has_value()) return kInvalidOffset; } if (zip32CompressedSize == UINT32_MAX) { compressedFileSize = TryConsumeUnaligned(&readPtr, extraFieldStart, extraFieldLength); if (!compressedFileSize.has_value()) return kInvalidOffset; } if (zip32LocalFileHeaderOffset == UINT32_MAX) { localHeaderOffset = TryConsumeUnaligned(&readPtr, extraFieldStart, extraFieldLength); if (!localHeaderOffset.has_value()) return kInvalidOffset; } // calculate how many bytes we read after the data size field. size_t bytesRead = readPtr - (extraFieldStart + offset); if (bytesRead == 0) { ALOGW("Zip: Data size should not be 0 in zip64 extended field"); return kInvalidFile; } if (dataSize != bytesRead) { auto localOffsetString = zip32LocalFileHeaderOffset.has_value() ? std::to_string(zip32LocalFileHeaderOffset.value()) : "missing"; ALOGW("Zip: Invalid data size in zip64 extended field, expect %zu , get %" PRIu16 ", uncompressed size %" PRIu32 ", compressed size %" PRIu32 ", local header offset %s", bytesRead, dataSize, zip32UncompressedSize, zip32CompressedSize, localOffsetString.c_str()); return kInvalidFile; } zip64Info->uncompressed_file_size = uncompressedFileSize; zip64Info->compressed_file_size = compressedFileSize; zip64Info->local_header_offset = localHeaderOffset; return kSuccess; } ALOGW("Zip: zip64 extended info isn't found in the extra field."); return kInvalidFile; } /* * Parses the Zip archive's Central Directory. Allocates and populates the * hash table. * * Returns 0 on success. */ static ZipError ParseZipArchive(ZipArchive* archive) { const uint8_t* const cd_ptr = archive->central_directory.GetBasePtr(); const size_t cd_length = archive->central_directory.GetMapLength(); const uint64_t num_entries = archive->num_entries; if (num_entries <= UINT16_MAX) { archive->cd_entry_map = CdEntryMapZip32::Create(static_cast(num_entries)); } else { archive->cd_entry_map = CdEntryMapZip64::Create(); } if (archive->cd_entry_map == nullptr) { return kAllocationFailed; } /* * Walk through the central directory, adding entries to the hash * table and verifying values. */ const uint8_t* const cd_end = cd_ptr + cd_length; const uint8_t* ptr = cd_ptr; for (uint64_t i = 0; i < num_entries; i++) { if (ptr > cd_end - sizeof(CentralDirectoryRecord)) { ALOGW("Zip: ran off the end (item #%" PRIu64 ", %zu bytes of central directory)", i, cd_length); #if defined(__ANDROID__) android_errorWriteLog(0x534e4554, "36392138"); #endif return kInvalidFile; } auto cdr = reinterpret_cast(ptr); if (cdr->record_signature != CentralDirectoryRecord::kSignature) { ALOGW("Zip: missed a central dir sig (at %" PRIu64 ")", i); return kInvalidFile; } const uint16_t file_name_length = cdr->file_name_length; const uint16_t extra_length = cdr->extra_field_length; const uint16_t comment_length = cdr->comment_length; const uint8_t* file_name = ptr + sizeof(CentralDirectoryRecord); if (file_name_length >= cd_length || file_name > cd_end - file_name_length) { ALOGW("Zip: file name for entry %" PRIu64 " exceeds the central directory range, file_name_length: %" PRIu16 ", cd_length: %zu", i, file_name_length, cd_length); return kInvalidEntryName; } const uint8_t* extra_field = file_name + file_name_length; if (extra_length >= cd_length || extra_field > cd_end - extra_length) { ALOGW("Zip: extra field for entry %" PRIu64 " exceeds the central directory range, file_name_length: %" PRIu16 ", cd_length: %zu", i, extra_length, cd_length); return kInvalidFile; } off64_t local_header_offset = cdr->local_file_header_offset; if (local_header_offset == UINT32_MAX) { Zip64ExtendedInfo zip64_info{}; if (auto status = ParseZip64ExtendedInfoInExtraField( extra_field, extra_length, cdr->uncompressed_size, cdr->compressed_size, cdr->local_file_header_offset, &zip64_info); status != kSuccess) { return status; } CHECK(zip64_info.local_header_offset.has_value()); local_header_offset = zip64_info.local_header_offset.value(); } if (local_header_offset >= archive->directory_offset) { ALOGW("Zip: bad LFH offset %" PRId64 " at entry %" PRIu64, static_cast(local_header_offset), i); return kInvalidFile; } // Check that file name is valid UTF-8 and doesn't contain NUL (U+0000) characters. if (!IsValidEntryName(file_name, file_name_length)) { ALOGW("Zip: invalid file name at entry %" PRIu64, i); return kInvalidEntryName; } // Add the CDE filename to the hash table. std::string_view entry_name{reinterpret_cast(file_name), file_name_length}; if (auto add_result = archive->cd_entry_map->AddToMap(entry_name, archive->central_directory.GetBasePtr()); add_result != 0) { ALOGW("Zip: Error adding entry to hash table %d", add_result); return add_result; } ptr += sizeof(CentralDirectoryRecord) + file_name_length + extra_length + comment_length; if ((ptr - cd_ptr) > static_cast(cd_length)) { ALOGW("Zip: bad CD advance (%tu vs %zu) at entry %" PRIu64, ptr - cd_ptr, cd_length, i); return kInvalidFile; } } uint32_t lfh_start_bytes; if (!archive->mapped_zip.ReadAtOffset(reinterpret_cast(&lfh_start_bytes), sizeof(uint32_t), 0)) { ALOGW("Zip: Unable to read header for entry at offset == 0."); return kInvalidFile; } if (lfh_start_bytes != LocalFileHeader::kSignature) { ALOGW("Zip: Entry at offset zero has invalid LFH signature %" PRIx32, lfh_start_bytes); #if defined(__ANDROID__) android_errorWriteLog(0x534e4554, "64211847"); #endif return kInvalidFile; } ALOGV("+++ zip good scan %" PRIu64 " entries", num_entries); return kSuccess; } static int32_t OpenArchiveInternal(ZipArchive* archive, const char* debug_file_name) { int32_t result = MapCentralDirectory(debug_file_name, archive); return result != kSuccess ? result : ParseZipArchive(archive); } int32_t OpenArchiveFd(int fd, const char* debug_file_name, ZipArchiveHandle* handle, bool assume_ownership) { ZipArchive* archive = new ZipArchive(MappedZipFile(fd), assume_ownership); *handle = archive; return OpenArchiveInternal(archive, debug_file_name); } int32_t OpenArchiveFdRange(int fd, const char* debug_file_name, ZipArchiveHandle* handle, off64_t length, off64_t offset, bool assume_ownership) { ZipArchive* archive = new ZipArchive(MappedZipFile(fd, length, offset), assume_ownership); *handle = archive; if (length < 0) { ALOGW("Invalid zip length %" PRId64, length); return kIoError; } if (offset < 0) { ALOGW("Invalid zip offset %" PRId64, offset); return kIoError; } return OpenArchiveInternal(archive, debug_file_name); } int32_t OpenArchive(const char* fileName, ZipArchiveHandle* handle) { const int fd = ::android::base::utf8::open(fileName, O_RDONLY | O_BINARY | O_CLOEXEC, 0); ZipArchive* archive = new ZipArchive(MappedZipFile(fd), true); *handle = archive; if (fd < 0) { ALOGW("Unable to open '%s': %s", fileName, strerror(errno)); return kIoError; } return OpenArchiveInternal(archive, fileName); } int32_t OpenArchiveFromMemory(const void* address, size_t length, const char* debug_file_name, ZipArchiveHandle* handle) { ZipArchive* archive = new ZipArchive(address, length); *handle = archive; return OpenArchiveInternal(archive, debug_file_name); } ZipArchiveInfo GetArchiveInfo(ZipArchiveHandle archive) { ZipArchiveInfo result; result.archive_size = archive->mapped_zip.GetFileLength(); result.entry_count = archive->num_entries; return result; } /* * Close a ZipArchive, closing the file and freeing the contents. */ void CloseArchive(ZipArchiveHandle archive) { ALOGV("Closing archive %p", archive); delete archive; } static int32_t ValidateDataDescriptor(MappedZipFile& mapped_zip, const ZipEntry64* entry) { // Maximum possible size for data descriptor: 2 * 4 + 2 * 8 = 24 bytes // The zip format doesn't specify the size of data descriptor. But we won't read OOB here even // if the descriptor isn't present. Because the size cd + eocd in the end of the zipfile is // larger than 24 bytes. And if the descriptor contains invalid data, we'll abort due to // kInconsistentInformation. uint8_t ddBuf[24]; off64_t offset = entry->offset; if (entry->method != kCompressStored) { offset += entry->compressed_length; } else { offset += entry->uncompressed_length; } if (!mapped_zip.ReadAtOffset(ddBuf, sizeof(ddBuf), offset)) { return kIoError; } const uint32_t ddSignature = *(reinterpret_cast(ddBuf)); uint8_t* ddReadPtr = (ddSignature == DataDescriptor::kOptSignature) ? ddBuf + 4 : ddBuf; DataDescriptor descriptor{}; descriptor.crc32 = ConsumeUnaligned(&ddReadPtr); if (entry->zip64_format_size) { descriptor.compressed_size = ConsumeUnaligned(&ddReadPtr); descriptor.uncompressed_size = ConsumeUnaligned(&ddReadPtr); } else { descriptor.compressed_size = ConsumeUnaligned(&ddReadPtr); descriptor.uncompressed_size = ConsumeUnaligned(&ddReadPtr); } // Validate that the values in the data descriptor match those in the central // directory. if (entry->compressed_length != descriptor.compressed_size || entry->uncompressed_length != descriptor.uncompressed_size || entry->crc32 != descriptor.crc32) { ALOGW("Zip: size/crc32 mismatch. expected {%" PRIu64 ", %" PRIu64 ", %" PRIx32 "}, was {%" PRIu64 ", %" PRIu64 ", %" PRIx32 "}", entry->compressed_length, entry->uncompressed_length, entry->crc32, descriptor.compressed_size, descriptor.uncompressed_size, descriptor.crc32); return kInconsistentInformation; } return 0; } static int32_t FindEntry(const ZipArchive* archive, std::string_view entryName, const uint64_t nameOffset, ZipEntry64* data) { // Recover the start of the central directory entry from the filename // pointer. The filename is the first entry past the fixed-size data, // so we can just subtract back from that. const uint8_t* base_ptr = archive->central_directory.GetBasePtr(); const uint8_t* ptr = base_ptr + nameOffset; ptr -= sizeof(CentralDirectoryRecord); // This is the base of our mmapped region, we have to check that // the name that's in the hash table is a pointer to a location within // this mapped region. if (ptr < base_ptr || ptr > base_ptr + archive->central_directory.GetMapLength()) { ALOGW("Zip: Invalid entry pointer"); return kInvalidOffset; } auto cdr = reinterpret_cast(ptr); // The offset of the start of the central directory in the zipfile. // We keep this lying around so that we can check all our lengths // and our per-file structures. const off64_t cd_offset = archive->directory_offset; // Fill out the compression method, modification time, crc32 // and other interesting attributes from the central directory. These // will later be compared against values from the local file header. data->method = cdr->compression_method; data->mod_time = cdr->last_mod_date << 16 | cdr->last_mod_time; data->crc32 = cdr->crc32; data->compressed_length = cdr->compressed_size; data->uncompressed_length = cdr->uncompressed_size; // Figure out the local header offset from the central directory. The // actual file data will begin after the local header and the name / // extra comments. off64_t local_header_offset = cdr->local_file_header_offset; // One of the info field is UINT32_MAX, try to parse the real value in the zip64 extended info in // the extra field. if (cdr->uncompressed_size == UINT32_MAX || cdr->compressed_size == UINT32_MAX || cdr->local_file_header_offset == UINT32_MAX) { const uint8_t* extra_field = ptr + sizeof(CentralDirectoryRecord) + cdr->file_name_length; Zip64ExtendedInfo zip64_info{}; if (auto status = ParseZip64ExtendedInfoInExtraField( extra_field, cdr->extra_field_length, cdr->uncompressed_size, cdr->compressed_size, cdr->local_file_header_offset, &zip64_info); status != kSuccess) { return status; } data->uncompressed_length = zip64_info.uncompressed_file_size.value_or(cdr->uncompressed_size); data->compressed_length = zip64_info.compressed_file_size.value_or(cdr->compressed_size); local_header_offset = zip64_info.local_header_offset.value_or(local_header_offset); data->zip64_format_size = cdr->uncompressed_size == UINT32_MAX || cdr->compressed_size == UINT32_MAX; } if (local_header_offset + static_cast(sizeof(LocalFileHeader)) >= cd_offset) { ALOGW("Zip: bad local hdr offset in zip"); return kInvalidOffset; } uint8_t lfh_buf[sizeof(LocalFileHeader)]; if (!archive->mapped_zip.ReadAtOffset(lfh_buf, sizeof(lfh_buf), local_header_offset)) { ALOGW("Zip: failed reading lfh name from offset %" PRId64, static_cast(local_header_offset)); return kIoError; } auto lfh = reinterpret_cast(lfh_buf); if (lfh->lfh_signature != LocalFileHeader::kSignature) { ALOGW("Zip: didn't find signature at start of lfh, offset=%" PRId64, static_cast(local_header_offset)); return kInvalidOffset; } // Check that the local file header name matches the declared name in the central directory. CHECK_LE(entryName.size(), UINT16_MAX); auto nameLen = static_cast(entryName.size()); if (lfh->file_name_length != nameLen) { ALOGW("Zip: lfh name length did not match central directory for %s: %" PRIu16 " %" PRIu16, std::string(entryName).c_str(), lfh->file_name_length, nameLen); return kInconsistentInformation; } const off64_t name_offset = local_header_offset + sizeof(LocalFileHeader); if (name_offset > cd_offset - lfh->file_name_length) { ALOGW("Zip: lfh name has invalid declared length"); return kInvalidOffset; } std::vector name_buf(nameLen); if (!archive->mapped_zip.ReadAtOffset(name_buf.data(), nameLen, name_offset)) { ALOGW("Zip: failed reading lfh name from offset %" PRId64, static_cast(name_offset)); return kIoError; } if (memcmp(entryName.data(), name_buf.data(), nameLen) != 0) { ALOGW("Zip: lfh name did not match central directory"); return kInconsistentInformation; } uint64_t lfh_uncompressed_size = lfh->uncompressed_size; uint64_t lfh_compressed_size = lfh->compressed_size; if (lfh_uncompressed_size == UINT32_MAX || lfh_compressed_size == UINT32_MAX) { if (lfh_uncompressed_size != UINT32_MAX || lfh_compressed_size != UINT32_MAX) { ALOGW( "Zip: The zip64 extended field in the local header MUST include BOTH original and " "compressed file size fields."); return kInvalidFile; } const off64_t lfh_extra_field_offset = name_offset + lfh->file_name_length; const uint16_t lfh_extra_field_size = lfh->extra_field_length; if (lfh_extra_field_offset > cd_offset - lfh_extra_field_size) { ALOGW("Zip: extra field has a bad size for entry %s", std::string(entryName).c_str()); return kInvalidOffset; } std::vector local_extra_field(lfh_extra_field_size); if (!archive->mapped_zip.ReadAtOffset(local_extra_field.data(), lfh_extra_field_size, lfh_extra_field_offset)) { ALOGW("Zip: failed reading lfh extra field from offset %" PRId64, lfh_extra_field_offset); return kIoError; } Zip64ExtendedInfo zip64_info{}; if (auto status = ParseZip64ExtendedInfoInExtraField( local_extra_field.data(), lfh_extra_field_size, lfh->uncompressed_size, lfh->compressed_size, std::nullopt, &zip64_info); status != kSuccess) { return status; } CHECK(zip64_info.uncompressed_file_size.has_value()); CHECK(zip64_info.compressed_file_size.has_value()); lfh_uncompressed_size = zip64_info.uncompressed_file_size.value(); lfh_compressed_size = zip64_info.compressed_file_size.value(); } // Paranoia: Match the values specified in the local file header // to those specified in the central directory. // Warn if central directory and local file header don't agree on the use // of a trailing Data Descriptor. The reference implementation is inconsistent // and appears to use the LFH value during extraction (unzip) but the CD value // while displayng information about archives (zipinfo). The spec remains // silent on this inconsistency as well. // // For now, always use the version from the LFH but make sure that the values // specified in the central directory match those in the data descriptor. // // NOTE: It's also worth noting that unzip *does* warn about inconsistencies in // bit 11 (EFS: The language encoding flag, marking that filename and comment are // encoded using UTF-8). This implementation does not check for the presence of // that flag and always enforces that entry names are valid UTF-8. if ((lfh->gpb_flags & kGPBDDFlagMask) != (cdr->gpb_flags & kGPBDDFlagMask)) { ALOGW("Zip: gpb flag mismatch at bit 3. expected {%04" PRIx16 "}, was {%04" PRIx16 "}", cdr->gpb_flags, lfh->gpb_flags); } // If there is no trailing data descriptor, verify that the central directory and local file // header agree on the crc, compressed, and uncompressed sizes of the entry. if ((lfh->gpb_flags & kGPBDDFlagMask) == 0) { data->has_data_descriptor = 0; if (data->compressed_length != lfh_compressed_size || data->uncompressed_length != lfh_uncompressed_size || data->crc32 != lfh->crc32) { ALOGW("Zip: size/crc32 mismatch. expected {%" PRIu64 ", %" PRIu64 ", %" PRIx32 "}, was {%" PRIu64 ", %" PRIu64 ", %" PRIx32 "}", data->compressed_length, data->uncompressed_length, data->crc32, lfh_compressed_size, lfh_uncompressed_size, lfh->crc32); return kInconsistentInformation; } } else { data->has_data_descriptor = 1; } // 4.4.2.1: the upper byte of `version_made_by` gives the source OS. Unix is 3. data->version_made_by = cdr->version_made_by; data->external_file_attributes = cdr->external_file_attributes; if ((data->version_made_by >> 8) == 3) { data->unix_mode = (cdr->external_file_attributes >> 16) & 0xffff; } else { data->unix_mode = 0777; } // 4.4.4: general purpose bit flags. data->gpbf = lfh->gpb_flags; // 4.4.14: the lowest bit of the internal file attributes field indicates text. // Currently only needed to implement zipinfo. data->is_text = (cdr->internal_file_attributes & 1); const off64_t data_offset = local_header_offset + sizeof(LocalFileHeader) + lfh->file_name_length + lfh->extra_field_length; if (data_offset > cd_offset) { ALOGW("Zip: bad data offset %" PRId64 " in zip", static_cast(data_offset)); return kInvalidOffset; } if (data->compressed_length > cd_offset - data_offset) { ALOGW("Zip: bad compressed length in zip (%" PRId64 " + %" PRIu64 " > %" PRId64 ")", static_cast(data_offset), data->compressed_length, static_cast(cd_offset)); return kInvalidOffset; } if (data->method == kCompressStored && data->uncompressed_length > cd_offset - data_offset) { ALOGW("Zip: bad uncompressed length in zip (%" PRId64 " + %" PRIu64 " > %" PRId64 ")", static_cast(data_offset), data->uncompressed_length, static_cast(cd_offset)); return kInvalidOffset; } data->offset = data_offset; return 0; } struct IterationHandle { ZipArchive* archive; std::function matcher; uint32_t position = 0; IterationHandle(ZipArchive* archive, std::function in_matcher) : archive(archive), matcher(std::move(in_matcher)) {} bool Match(std::string_view entry_name) const { return matcher(entry_name); } }; int32_t StartIteration(ZipArchiveHandle archive, void** cookie_ptr, const std::string_view optional_prefix, const std::string_view optional_suffix) { if (optional_prefix.size() > static_cast(UINT16_MAX) || optional_suffix.size() > static_cast(UINT16_MAX)) { ALOGW("Zip: prefix/suffix too long"); return kInvalidEntryName; } auto matcher = [prefix = std::string(optional_prefix), suffix = std::string(optional_suffix)](std::string_view name) mutable { return android::base::StartsWith(name, prefix) && android::base::EndsWith(name, suffix); }; return StartIteration(archive, cookie_ptr, std::move(matcher)); } int32_t StartIteration(ZipArchiveHandle archive, void** cookie_ptr, std::function matcher) { if (archive == nullptr || archive->cd_entry_map == nullptr) { ALOGW("Zip: Invalid ZipArchiveHandle"); return kInvalidHandle; } archive->cd_entry_map->ResetIteration(); *cookie_ptr = new IterationHandle(archive, matcher); return 0; } void EndIteration(void* cookie) { delete reinterpret_cast(cookie); } int32_t ZipEntry::CopyFromZipEntry64(ZipEntry* dst, const ZipEntry64* src) { if (src->compressed_length > UINT32_MAX || src->uncompressed_length > UINT32_MAX) { ALOGW( "Zip: the entry size is too large to fit into the 32 bits ZipEntry, uncompressed " "length %" PRIu64 ", compressed length %" PRIu64, src->uncompressed_length, src->compressed_length); return kUnsupportedEntrySize; } *dst = *src; dst->uncompressed_length = static_cast(src->uncompressed_length); dst->compressed_length = static_cast(src->compressed_length); return kSuccess; } int32_t FindEntry(const ZipArchiveHandle archive, const std::string_view entryName, ZipEntry* data) { ZipEntry64 entry64; if (auto status = FindEntry(archive, entryName, &entry64); status != kSuccess) { return status; } return ZipEntry::CopyFromZipEntry64(data, &entry64); } int32_t FindEntry(const ZipArchiveHandle archive, const std::string_view entryName, ZipEntry64* data) { if (entryName.empty() || entryName.size() > static_cast(UINT16_MAX)) { ALOGW("Zip: Invalid filename of length %zu", entryName.size()); return kInvalidEntryName; } const auto [result, offset] = archive->cd_entry_map->GetCdEntryOffset(entryName, archive->central_directory.GetBasePtr()); if (result != 0) { ALOGV("Zip: Could not find entry %.*s", static_cast(entryName.size()), entryName.data()); return static_cast(result); // kEntryNotFound is safe to truncate. } // We know there are at most hash_table_size entries, safe to truncate. return FindEntry(archive, entryName, offset, data); } int32_t Next(void* cookie, ZipEntry* data, std::string* name) { ZipEntry64 entry64; if (auto status = Next(cookie, &entry64, name); status != kSuccess) { return status; } return ZipEntry::CopyFromZipEntry64(data, &entry64); } int32_t Next(void* cookie, ZipEntry* data, std::string_view* name) { ZipEntry64 entry64; if (auto status = Next(cookie, &entry64, name); status != kSuccess) { return status; } return ZipEntry::CopyFromZipEntry64(data, &entry64); } int32_t Next(void* cookie, ZipEntry64* data, std::string* name) { std::string_view sv; int32_t result = Next(cookie, data, &sv); if (result == 0 && name) { *name = std::string(sv); } return result; } int32_t Next(void* cookie, ZipEntry64* data, std::string_view* name) { IterationHandle* handle = reinterpret_cast(cookie); if (handle == nullptr) { ALOGW("Zip: Null ZipArchiveHandle"); return kInvalidHandle; } ZipArchive* archive = handle->archive; if (archive == nullptr || archive->cd_entry_map == nullptr) { ALOGW("Zip: Invalid ZipArchiveHandle"); return kInvalidHandle; } auto entry = archive->cd_entry_map->Next(archive->central_directory.GetBasePtr()); while (entry != std::pair()) { const auto [entry_name, offset] = entry; if (handle->Match(entry_name)) { const int error = FindEntry(archive, entry_name, offset, data); if (!error && name) { *name = entry_name; } return error; } entry = archive->cd_entry_map->Next(archive->central_directory.GetBasePtr()); } archive->cd_entry_map->ResetIteration(); return kIterationEnd; } // A Writer that writes data to a fixed size memory region. // The size of the memory region must be equal to the total size of // the data appended to it. class MemoryWriter : public zip_archive::Writer { public: static std::unique_ptr Create(uint8_t* buf, size_t size, const ZipEntry64* entry) { const uint64_t declared_length = entry->uncompressed_length; if (declared_length > size) { ALOGW("Zip: file size %" PRIu64 " is larger than the buffer size %zu.", declared_length, size); return nullptr; } return std::unique_ptr(new MemoryWriter(buf, size)); } virtual bool Append(uint8_t* buf, size_t buf_size) override { if (size_ < buf_size || bytes_written_ > size_ - buf_size) { ALOGW("Zip: Unexpected size %zu (declared) vs %zu (actual)", size_, bytes_written_ + buf_size); return false; } memcpy(buf_ + bytes_written_, buf, buf_size); bytes_written_ += buf_size; return true; } private: MemoryWriter(uint8_t* buf, size_t size) : Writer(), buf_(buf), size_(size), bytes_written_(0) {} uint8_t* const buf_{nullptr}; const size_t size_; size_t bytes_written_; }; // A Writer that appends data to a file |fd| at its current position. // The file will be truncated to the end of the written data. class FileWriter : public zip_archive::Writer { public: // Creates a FileWriter for |fd| and prepare to write |entry| to it, // guaranteeing that the file descriptor is valid and that there's enough // space on the volume to write out the entry completely and that the file // is truncated to the correct length (no truncation if |fd| references a // block device). // // Returns a valid FileWriter on success, |nullptr| if an error occurred. static std::unique_ptr Create(int fd, const ZipEntry64* entry) { const uint64_t declared_length = entry->uncompressed_length; const off64_t current_offset = lseek64(fd, 0, SEEK_CUR); if (current_offset == -1) { ALOGW("Zip: unable to seek to current location on fd %d: %s", fd, strerror(errno)); return nullptr; } if (declared_length > SIZE_MAX || declared_length > INT64_MAX) { ALOGW("Zip: file size %" PRIu64 " is too large to extract.", declared_length); return nullptr; } #if defined(__linux__) if (declared_length > 0) { // Make sure we have enough space on the volume to extract the compressed // entry. Note that the call to ftruncate below will change the file size but // will not allocate space on disk and this call to fallocate will not // change the file size. // Note: fallocate is only supported by the following filesystems - // btrfs, ext4, ocfs2, and xfs. Therefore fallocate might fail with // EOPNOTSUPP error when issued in other filesystems. // Hence, check for the return error code before concluding that the // disk does not have enough space. long result = TEMP_FAILURE_RETRY(fallocate(fd, 0, current_offset, declared_length)); if (result == -1 && errno == ENOSPC) { ALOGW("Zip: unable to allocate %" PRIu64 " bytes at offset %" PRId64 ": %s", declared_length, static_cast(current_offset), strerror(errno)); return nullptr; } } #endif // __linux__ struct stat sb; if (fstat(fd, &sb) == -1) { ALOGW("Zip: unable to fstat file: %s", strerror(errno)); return nullptr; } // Block device doesn't support ftruncate(2). if (!S_ISBLK(sb.st_mode)) { long result = TEMP_FAILURE_RETRY(ftruncate(fd, declared_length + current_offset)); if (result == -1) { ALOGW("Zip: unable to truncate file to %" PRId64 ": %s", static_cast(declared_length + current_offset), strerror(errno)); return nullptr; } } return std::unique_ptr(new FileWriter(fd, declared_length)); } FileWriter(FileWriter&& other) noexcept : fd_(other.fd_), declared_length_(other.declared_length_), total_bytes_written_(other.total_bytes_written_) { other.fd_ = -1; } virtual bool Append(uint8_t* buf, size_t buf_size) override { if (declared_length_ < buf_size || total_bytes_written_ > declared_length_ - buf_size) { ALOGW("Zip: Unexpected size %zu (declared) vs %zu (actual)", declared_length_, total_bytes_written_ + buf_size); return false; } const bool result = android::base::WriteFully(fd_, buf, buf_size); if (result) { total_bytes_written_ += buf_size; } else { ALOGW("Zip: unable to write %zu bytes to file; %s", buf_size, strerror(errno)); } return result; } private: explicit FileWriter(const int fd = -1, const uint64_t declared_length = 0) : Writer(), fd_(fd), declared_length_(static_cast(declared_length)), total_bytes_written_(0) { CHECK_LE(declared_length, SIZE_MAX); } int fd_; const size_t declared_length_; size_t total_bytes_written_; }; class EntryReader : public zip_archive::Reader { public: EntryReader(const MappedZipFile& zip_file, const ZipEntry64* entry) : Reader(), zip_file_(zip_file), entry_(entry) {} virtual bool ReadAtOffset(uint8_t* buf, size_t len, off64_t offset) const { return zip_file_.ReadAtOffset(buf, len, entry_->offset + offset); } virtual ~EntryReader() {} private: const MappedZipFile& zip_file_; const ZipEntry64* entry_; }; // This method is using libz macros with old-style-casts #pragma GCC diagnostic push #pragma GCC diagnostic ignored "-Wold-style-cast" static inline int zlib_inflateInit2(z_stream* stream, int window_bits) { return inflateInit2(stream, window_bits); } #pragma GCC diagnostic pop namespace zip_archive { // Moved out of line to avoid -Wweak-vtables. Reader::~Reader() {} Writer::~Writer() {} int32_t Inflate(const Reader& reader, const uint64_t compressed_length, const uint64_t uncompressed_length, Writer* writer, uint64_t* crc_out) { const size_t kBufSize = 32768; std::vector read_buf(kBufSize); std::vector write_buf(kBufSize); z_stream zstream; int zerr; /* * Initialize the zlib stream struct. */ memset(&zstream, 0, sizeof(zstream)); zstream.zalloc = Z_NULL; zstream.zfree = Z_NULL; zstream.opaque = Z_NULL; zstream.next_in = NULL; zstream.avail_in = 0; zstream.next_out = &write_buf[0]; zstream.avail_out = kBufSize; zstream.data_type = Z_UNKNOWN; /* * Use the undocumented "negative window bits" feature to tell zlib * that there's no zlib header waiting for it. */ zerr = zlib_inflateInit2(&zstream, -MAX_WBITS); if (zerr != Z_OK) { if (zerr == Z_VERSION_ERROR) { ALOGE("Installed zlib is not compatible with linked version (%s)", ZLIB_VERSION); } else { ALOGW("Call to inflateInit2 failed (zerr=%d)", zerr); } return kZlibError; } auto zstream_deleter = [](z_stream* stream) { inflateEnd(stream); /* free up any allocated structures */ }; std::unique_ptr zstream_guard(&zstream, zstream_deleter); const bool compute_crc = (crc_out != nullptr); uLong crc = 0; uint64_t remaining_bytes = compressed_length; uint64_t total_output = 0; do { /* read as much as we can */ if (zstream.avail_in == 0) { const uint32_t read_size = (remaining_bytes > kBufSize) ? kBufSize : static_cast(remaining_bytes); const off64_t offset = (compressed_length - remaining_bytes); // Make sure to read at offset to ensure concurrent access to the fd. if (!reader.ReadAtOffset(read_buf.data(), read_size, offset)) { ALOGW("Zip: inflate read failed, getSize = %u: %s", read_size, strerror(errno)); return kIoError; } remaining_bytes -= read_size; zstream.next_in = &read_buf[0]; zstream.avail_in = read_size; } /* uncompress the data */ zerr = inflate(&zstream, Z_NO_FLUSH); if (zerr != Z_OK && zerr != Z_STREAM_END) { ALOGW("Zip: inflate zerr=%d (nIn=%p aIn=%u nOut=%p aOut=%u)", zerr, zstream.next_in, zstream.avail_in, zstream.next_out, zstream.avail_out); return kZlibError; } /* write when we're full or when we're done */ if (zstream.avail_out == 0 || (zerr == Z_STREAM_END && zstream.avail_out != kBufSize)) { const size_t write_size = zstream.next_out - &write_buf[0]; if (!writer->Append(&write_buf[0], write_size)) { return kIoError; } else if (compute_crc) { DCHECK_LE(write_size, kBufSize); crc = crc32(crc, &write_buf[0], static_cast(write_size)); } total_output += kBufSize - zstream.avail_out; zstream.next_out = &write_buf[0]; zstream.avail_out = kBufSize; } } while (zerr == Z_OK); CHECK_EQ(zerr, Z_STREAM_END); /* other errors should've been caught */ // NOTE: zstream.adler is always set to 0, because we're using the -MAX_WBITS // "feature" of zlib to tell it there won't be a zlib file header. zlib // doesn't bother calculating the checksum in that scenario. We just do // it ourselves above because there are no additional gains to be made by // having zlib calculate it for us, since they do it by calling crc32 in // the same manner that we have above. if (compute_crc) { *crc_out = crc; } if (total_output != uncompressed_length || remaining_bytes != 0) { ALOGW("Zip: size mismatch on inflated file (%lu vs %" PRIu64 ")", zstream.total_out, uncompressed_length); return kInconsistentInformation; } return 0; } } // namespace zip_archive static int32_t InflateEntryToWriter(MappedZipFile& mapped_zip, const ZipEntry64* entry, zip_archive::Writer* writer, uint64_t* crc_out) { const EntryReader reader(mapped_zip, entry); return zip_archive::Inflate(reader, entry->compressed_length, entry->uncompressed_length, writer, crc_out); } static int32_t CopyEntryToWriter(MappedZipFile& mapped_zip, const ZipEntry64* entry, zip_archive::Writer* writer, uint64_t* crc_out) { static const uint32_t kBufSize = 32768; std::vector buf(kBufSize); const uint64_t length = entry->uncompressed_length; uint64_t count = 0; uLong crc = 0; while (count < length) { uint64_t remaining = length - count; off64_t offset = entry->offset + count; // Safe conversion because kBufSize is narrow enough for a 32 bit signed value. const uint32_t block_size = (remaining > kBufSize) ? kBufSize : static_cast(remaining); // Make sure to read at offset to ensure concurrent access to the fd. if (!mapped_zip.ReadAtOffset(buf.data(), block_size, offset)) { ALOGW("CopyFileToFile: copy read failed, block_size = %u, offset = %" PRId64 ": %s", block_size, static_cast(offset), strerror(errno)); return kIoError; } if (!writer->Append(&buf[0], block_size)) { return kIoError; } if (crc_out) { crc = crc32(crc, &buf[0], block_size); } count += block_size; } if (crc_out) { *crc_out = crc; } return 0; } int32_t ExtractToWriter(ZipArchiveHandle handle, const ZipEntry64* entry, zip_archive::Writer* writer) { const uint16_t method = entry->method; // this should default to kUnknownCompressionMethod. int32_t return_value = -1; uint64_t crc = 0; if (method == kCompressStored) { return_value = CopyEntryToWriter(handle->mapped_zip, entry, writer, kCrcChecksEnabled ? &crc : nullptr); } else if (method == kCompressDeflated) { return_value = InflateEntryToWriter(handle->mapped_zip, entry, writer, kCrcChecksEnabled ? &crc : nullptr); } if (!return_value && entry->has_data_descriptor) { return_value = ValidateDataDescriptor(handle->mapped_zip, entry); if (return_value) { return return_value; } } // Validate that the CRC matches the calculated value. if (kCrcChecksEnabled && (entry->crc32 != static_cast(crc))) { ALOGW("Zip: crc mismatch: expected %" PRIu32 ", was %" PRIu64, entry->crc32, crc); return kInconsistentInformation; } return return_value; } int32_t ExtractToMemory(ZipArchiveHandle archive, const ZipEntry* entry, uint8_t* begin, size_t size) { ZipEntry64 entry64(*entry); return ExtractToMemory(archive, &entry64, begin, size); } int32_t ExtractToMemory(ZipArchiveHandle archive, const ZipEntry64* entry, uint8_t* begin, size_t size) { auto writer = MemoryWriter::Create(begin, size, entry); if (!writer) { return kIoError; } return ExtractToWriter(archive, entry, writer.get()); } int32_t ExtractEntryToFile(ZipArchiveHandle archive, const ZipEntry* entry, int fd) { ZipEntry64 entry64(*entry); return ExtractEntryToFile(archive, &entry64, fd); } int32_t ExtractEntryToFile(ZipArchiveHandle archive, const ZipEntry64* entry, int fd) { auto writer = FileWriter::Create(fd, entry); if (!writer) { return kIoError; } return ExtractToWriter(archive, entry, writer.get()); } int GetFileDescriptor(const ZipArchiveHandle archive) { return archive->mapped_zip.GetFileDescriptor(); } off64_t GetFileDescriptorOffset(const ZipArchiveHandle archive) { return archive->mapped_zip.GetFileOffset(); } #if !defined(_WIN32) class ProcessWriter : public zip_archive::Writer { public: ProcessWriter(ProcessZipEntryFunction func, void* cookie) : Writer(), proc_function_(func), cookie_(cookie) {} virtual bool Append(uint8_t* buf, size_t buf_size) override { return proc_function_(buf, buf_size, cookie_); } private: ProcessZipEntryFunction proc_function_; void* cookie_; }; int32_t ProcessZipEntryContents(ZipArchiveHandle archive, const ZipEntry* entry, ProcessZipEntryFunction func, void* cookie) { ZipEntry64 entry64(*entry); return ProcessZipEntryContents(archive, &entry64, func, cookie); } int32_t ProcessZipEntryContents(ZipArchiveHandle archive, const ZipEntry64* entry, ProcessZipEntryFunction func, void* cookie) { ProcessWriter writer(func, cookie); return ExtractToWriter(archive, entry, &writer); } #endif //! defined(_WIN32) int MappedZipFile::GetFileDescriptor() const { if (!has_fd_) { ALOGW("Zip: MappedZipFile doesn't have a file descriptor."); return -1; } return fd_; } const void* MappedZipFile::GetBasePtr() const { if (has_fd_) { ALOGW("Zip: MappedZipFile doesn't have a base pointer."); return nullptr; } return base_ptr_; } off64_t MappedZipFile::GetFileOffset() const { return fd_offset_; } off64_t MappedZipFile::GetFileLength() const { if (has_fd_) { if (data_length_ != -1) { return data_length_; } data_length_ = lseek64(fd_, 0, SEEK_END); if (data_length_ == -1) { ALOGE("Zip: lseek on fd %d failed: %s", fd_, strerror(errno)); } return data_length_; } else { if (base_ptr_ == nullptr) { ALOGE("Zip: invalid file map"); return -1; } return data_length_; } } // Attempts to read |len| bytes into |buf| at offset |off|. bool MappedZipFile::ReadAtOffset(uint8_t* buf, size_t len, off64_t off) const { if (has_fd_) { if (off < 0) { ALOGE("Zip: invalid offset %" PRId64, off); return false; } off64_t read_offset; if (__builtin_add_overflow(fd_offset_, off, &read_offset)) { ALOGE("Zip: invalid read offset %" PRId64 " overflows, fd offset %" PRId64, off, fd_offset_); return false; } if (data_length_ != -1) { off64_t read_end; if (len > std::numeric_limits::max() || __builtin_add_overflow(off, static_cast(len), &read_end)) { ALOGE("Zip: invalid read length %" PRId64 " overflows, offset %" PRId64, static_cast(len), off); return false; } if (read_end > data_length_) { ALOGE("Zip: invalid read length %" PRId64 " exceeds data length %" PRId64 ", offset %" PRId64, static_cast(len), data_length_, off); return false; } } if (!android::base::ReadFullyAtOffset(fd_, buf, len, read_offset)) { ALOGE("Zip: failed to read at offset %" PRId64, off); return false; } } else { if (off < 0 || data_length_ < len || off > data_length_ - len) { ALOGE("Zip: invalid offset: %" PRId64 ", read length: %zu, data length: %" PRId64, off, len, data_length_); return false; } memcpy(buf, static_cast(base_ptr_) + off, len); } return true; } void CentralDirectory::Initialize(const void* map_base_ptr, off64_t cd_start_offset, size_t cd_size) { base_ptr_ = static_cast(map_base_ptr) + cd_start_offset; length_ = cd_size; } bool ZipArchive::InitializeCentralDirectory(off64_t cd_start_offset, size_t cd_size) { if (mapped_zip.HasFd()) { directory_map = android::base::MappedFile::FromFd(mapped_zip.GetFileDescriptor(), mapped_zip.GetFileOffset() + cd_start_offset, cd_size, PROT_READ); if (!directory_map) { ALOGE("Zip: failed to map central directory (offset %" PRId64 ", size %zu): %s", cd_start_offset, cd_size, strerror(errno)); return false; } CHECK_EQ(directory_map->size(), cd_size); central_directory.Initialize(directory_map->data(), 0 /*offset*/, cd_size); } else { if (mapped_zip.GetBasePtr() == nullptr) { ALOGE("Zip: Failed to map central directory, bad mapped_zip base pointer"); return false; } if (static_cast(cd_start_offset) + static_cast(cd_size) > mapped_zip.GetFileLength()) { ALOGE( "Zip: Failed to map central directory, offset exceeds mapped memory region (" "start_offset %" PRId64 ", cd_size %zu, mapped_region_size %" PRId64 ")", static_cast(cd_start_offset), cd_size, mapped_zip.GetFileLength()); return false; } central_directory.Initialize(mapped_zip.GetBasePtr(), cd_start_offset, cd_size); } return true; } // This function returns the embedded timestamp as is; and doesn't perform validations. tm ZipEntryCommon::GetModificationTime() const { tm t = {}; t.tm_hour = (mod_time >> 11) & 0x1f; t.tm_min = (mod_time >> 5) & 0x3f; t.tm_sec = (mod_time & 0x1f) << 1; t.tm_year = ((mod_time >> 25) & 0x7f) + 80; t.tm_mon = ((mod_time >> 21) & 0xf) - 1; t.tm_mday = (mod_time >> 16) & 0x1f; return t; }