/* * 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. */ #include #include #include #include #include #include #include #include #include #include #include #include #include // TEMP_FAILURE_RETRY may or may not be in unistd #include "ziparchive/zip_archive.h" // This is for windows. If we don't open a file in binary mode, weird // things will happen. #ifndef O_BINARY #define O_BINARY 0 #endif #define DISALLOW_IMPLICIT_CONSTRUCTORS(TypeName) \ TypeName(); \ TypeName(const TypeName&); \ void operator=(const TypeName&) // The "end of central directory" (EOCD) record. Each archive // contains exactly once such record which appears at the end of // the archive. It contains archive wide information like the // number of entries in the archive and the offset to the central // directory of the offset. struct EocdRecord { static const uint32_t kSignature = 0x06054b50; // End of central directory signature, should always be // |kSignature|. uint32_t eocd_signature; // The number of the current "disk", i.e, the "disk" that this // central directory is on. // // This implementation assumes that each archive spans a single // disk only. i.e, that disk_num == 1. uint16_t disk_num; // The disk where the central directory starts. // // This implementation assumes that each archive spans a single // disk only. i.e, that cd_start_disk == 1. uint16_t cd_start_disk; // The number of central directory records on this disk. // // This implementation assumes that each archive spans a single // disk only. i.e, that num_records_on_disk == num_records. uint16_t num_records_on_disk; // The total number of central directory records. uint16_t num_records; // The size of the central directory (in bytes). uint32_t cd_size; // The offset of the start of the central directory, relative // to the start of the file. uint32_t cd_start_offset; // Length of the central directory comment. uint16_t comment_length; private: DISALLOW_IMPLICIT_CONSTRUCTORS(EocdRecord); } __attribute__((packed)); // A structure representing the fixed length fields for a single // record in the central directory of the archive. In addition to // the fixed length fields listed here, each central directory // record contains a variable length "file_name" and "extra_field" // whose lengths are given by |file_name_length| and |extra_field_length| // respectively. struct CentralDirectoryRecord { static const uint32_t kSignature = 0x02014b50; // The start of record signature. Must be |kSignature|. uint32_t record_signature; // Tool version. Ignored by this implementation. uint16_t version_made_by; // Tool version. Ignored by this implementation. uint16_t version_needed; // The "general purpose bit flags" for this entry. The only // flag value that we currently check for is the "data descriptor" // flag. uint16_t gpb_flags; // The compression method for this entry, one of |kCompressStored| // and |kCompressDeflated|. uint16_t compression_method; // The file modification time and date for this entry. uint16_t last_mod_time; uint16_t last_mod_date; // The CRC-32 checksum for this entry. uint32_t crc32; // The compressed size (in bytes) of this entry. uint32_t compressed_size; // The uncompressed size (in bytes) of this entry. uint32_t uncompressed_size; // The length of the entry file name in bytes. The file name // will appear immediately after this record. uint16_t file_name_length; // The length of the extra field info (in bytes). This data // will appear immediately after the entry file name. uint16_t extra_field_length; // The length of the entry comment (in bytes). This data will // appear immediately after the extra field. uint16_t comment_length; // The start disk for this entry. Ignored by this implementation). uint16_t file_start_disk; // File attributes. Ignored by this implementation. uint16_t internal_file_attributes; // File attributes. Ignored by this implementation. uint32_t external_file_attributes; // The offset to the local file header for this entry, from the // beginning of this archive. uint32_t local_file_header_offset; private: DISALLOW_IMPLICIT_CONSTRUCTORS(CentralDirectoryRecord); } __attribute__((packed)); // The local file header for a given entry. This duplicates information // present in the central directory of the archive. It is an error for // the information here to be different from the central directory // information for a given entry. struct LocalFileHeader { static const uint32_t kSignature = 0x04034b50; // The local file header signature, must be |kSignature|. uint32_t lfh_signature; // Tool version. Ignored by this implementation. uint16_t version_needed; // The "general purpose bit flags" for this entry. The only // flag value that we currently check for is the "data descriptor" // flag. uint16_t gpb_flags; // The compression method for this entry, one of |kCompressStored| // and |kCompressDeflated|. uint16_t compression_method; // The file modification time and date for this entry. uint16_t last_mod_time; uint16_t last_mod_date; // The CRC-32 checksum for this entry. uint32_t crc32; // The compressed size (in bytes) of this entry. uint32_t compressed_size; // The uncompressed size (in bytes) of this entry. uint32_t uncompressed_size; // The length of the entry file name in bytes. The file name // will appear immediately after this record. uint16_t file_name_length; // The length of the extra field info (in bytes). This data // will appear immediately after the entry file name. uint16_t extra_field_length; private: DISALLOW_IMPLICIT_CONSTRUCTORS(LocalFileHeader); } __attribute__((packed)); struct DataDescriptor { // The *optional* data descriptor start signature. static const uint32_t kOptSignature = 0x08074b50; // CRC-32 checksum of the entry. uint32_t crc32; // Compressed size of the entry. uint32_t compressed_size; // Uncompressed size of the entry. uint32_t uncompressed_size; private: DISALLOW_IMPLICIT_CONSTRUCTORS(DataDescriptor); } __attribute__((packed)); #undef DISALLOW_IMPLICIT_CONSTRUCTORS static const uint32_t kGPBDDFlagMask = 0x0008; // mask value that signifies that the entry has a DD static const uint32_t kMaxErrorLen = 1024; // The maximum size of a central directory or a file // comment in bytes. static const uint32_t kMaxCommentLen = 65535; // The maximum number of bytes to scan backwards for the EOCD start. static const uint32_t kMaxEOCDSearch = kMaxCommentLen + sizeof(EocdRecord); static const char* kErrorMessages[] = { "Unknown return code.", "Iteration ended", "Zlib error", "Invalid file", "Invalid handle", "Duplicate entries in archive", "Empty archive", "Entry not found", "Invalid offset", "Inconsistent information", "Invalid entry name", "I/O Error", "File mapping failed" }; static const int32_t kErrorMessageUpperBound = 0; static const int32_t kIterationEnd = -1; // We encountered a Zlib error when inflating a stream from this file. // Usually indicates file corruption. static const int32_t kZlibError = -2; // The input file cannot be processed as a zip archive. Usually because // it's too small, too large or does not have a valid signature. static const int32_t kInvalidFile = -3; // An invalid iteration / ziparchive handle was passed in as an input // argument. static const int32_t kInvalidHandle = -4; // The zip archive contained two (or possibly more) entries with the same // name. static const int32_t kDuplicateEntry = -5; // The zip archive contains no entries. static const int32_t kEmptyArchive = -6; // The specified entry was not found in the archive. static const int32_t kEntryNotFound = -7; // The zip archive contained an invalid local file header pointer. static const int32_t kInvalidOffset = -8; // The zip archive contained inconsistent entry information. This could // be because the central directory & local file header did not agree, or // if the actual uncompressed length or crc32 do not match their declared // values. static const int32_t kInconsistentInformation = -9; // An invalid entry name was encountered. static const int32_t kInvalidEntryName = -10; // An I/O related system call (read, lseek, ftruncate, map) failed. static const int32_t kIoError = -11; // We were not able to mmap the central directory or entry contents. static const int32_t kMmapFailed = -12; static const int32_t kErrorMessageLowerBound = -13; static const char kTempMappingFileName[] = "zip: ExtractFileToFile"; /* * 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. */ struct ZipArchive { /* open Zip archive */ const int fd; /* mapped central directory area */ off64_t directory_offset; android::FileMap* directory_map; /* number of entries in the Zip archive */ uint16_t num_entries; /* * We know how many entries are in the Zip archive, so we can have a * fixed-size hash table. We define a load factor of 0.75 and overallocat * so the maximum number entries can never be higher than * ((4 * UINT16_MAX) / 3 + 1) which can safely fit into a uint32_t. */ uint32_t hash_table_size; ZipEntryName* hash_table; ZipArchive(const int fd) : fd(fd), directory_offset(0), directory_map(NULL), num_entries(0), hash_table_size(0), hash_table(NULL) {} ~ZipArchive() { if (fd >= 0) { close(fd); } if (directory_map != NULL) { directory_map->release(); } free(hash_table); } }; // Returns 0 on success and negative values on failure. static android::FileMap* MapFileSegment(const int fd, const off64_t start, const size_t length, const bool read_only, const char* debug_file_name) { android::FileMap* file_map = new android::FileMap; const bool success = file_map->create(debug_file_name, fd, start, length, read_only); if (!success) { file_map->release(); return NULL; } return file_map; } static int32_t CopyFileToFile(int fd, uint8_t* begin, const uint32_t length, uint64_t *crc_out) { static const uint32_t kBufSize = 32768; uint8_t buf[kBufSize]; uint32_t count = 0; uint64_t crc = 0; while (count < length) { uint32_t remaining = length - count; // Safe conversion because kBufSize is narrow enough for a 32 bit signed // value. ssize_t get_size = (remaining > kBufSize) ? kBufSize : remaining; ssize_t actual = TEMP_FAILURE_RETRY(read(fd, buf, get_size)); if (actual != get_size) { ALOGW("CopyFileToFile: copy read failed (" ZD " vs " ZD ")", actual, get_size); return kIoError; } memcpy(begin + count, buf, get_size); crc = crc32(crc, buf, get_size); count += get_size; } *crc_out = crc; return 0; } /* * Round up to the next highest power of 2. * * Found on http://graphics.stanford.edu/~seander/bithacks.html. */ static uint32_t RoundUpPower2(uint32_t val) { val--; val |= val >> 1; val |= val >> 2; val |= val >> 4; val |= val >> 8; val |= val >> 16; val++; return val; } static uint32_t ComputeHash(const ZipEntryName& name) { uint32_t hash = 0; uint16_t len = name.name_length; const uint8_t* str = name.name; while (len--) { hash = hash * 31 + *str++; } return hash; } /* * Convert a ZipEntry to a hash table index, verifying that it's in a * valid range. */ static int64_t EntryToIndex(const ZipEntryName* hash_table, const uint32_t hash_table_size, const ZipEntryName& name) { const uint32_t hash = ComputeHash(name); // NOTE: (hash_table_size - 1) is guaranteed to be non-negative. uint32_t ent = hash & (hash_table_size - 1); while (hash_table[ent].name != NULL) { if (hash_table[ent].name_length == name.name_length && memcmp(hash_table[ent].name, name.name, name.name_length) == 0) { return ent; } ent = (ent + 1) & (hash_table_size - 1); } ALOGV("Zip: Unable to find entry %.*s", name.name_length, name.name); return kEntryNotFound; } /* * Add a new entry to the hash table. */ static int32_t AddToHash(ZipEntryName *hash_table, const uint64_t hash_table_size, const ZipEntryName& name) { const uint64_t hash = ComputeHash(name); uint32_t ent = hash & (hash_table_size - 1); /* * We over-allocated the table, so we're guaranteed to find an empty slot. * Further, we guarantee that the hashtable size is not 0. */ while (hash_table[ent].name != NULL) { if (hash_table[ent].name_length == name.name_length && memcmp(hash_table[ent].name, name.name, name.name_length) == 0) { // We've found a duplicate entry. We don't accept it ALOGW("Zip: Found duplicate entry %.*s", name.name_length, name.name); return kDuplicateEntry; } ent = (ent + 1) & (hash_table_size - 1); } hash_table[ent].name = name.name; hash_table[ent].name_length = name.name_length; return 0; } static int32_t MapCentralDirectory0(int fd, const char* debug_file_name, ZipArchive* archive, off64_t file_length, off64_t read_amount, uint8_t* scan_buffer) { const off64_t search_start = file_length - read_amount; if (lseek64(fd, search_start, SEEK_SET) != search_start) { ALOGW("Zip: seek %" PRId64 " failed: %s", static_cast(search_start), strerror(errno)); return kIoError; } ssize_t actual = TEMP_FAILURE_RETRY( read(fd, scan_buffer, static_cast(read_amount))); if (actual != static_cast(read_amount)) { ALOGW("Zip: read %" PRId64 " failed: %s", static_cast(read_amount), strerror(errno)); 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.) */ int i = read_amount - sizeof(EocdRecord); for (; i >= 0; i--) { if (scan_buffer[i] == 0x50 && ((*reinterpret_cast(&scan_buffer[i])) == 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; const EocdRecord* eocd = reinterpret_cast(scan_buffer + 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; } /* * Grab the CD offset and size, and the number of entries in the * archive and verify that they look reasonable. */ if (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; } if (eocd->num_records == 0) { ALOGW("Zip: empty archive?"); return kEmptyArchive; } ALOGV("+++ num_entries=%" PRIu32 "dir_size=%" PRIu32 " dir_offset=%" PRIu32, eocd->num_records, eocd->cd_size, eocd->cd_start_offset); /* * It all looks good. Create a mapping for the CD, and set the fields * in archive. */ android::FileMap* map = MapFileSegment(fd, static_cast(eocd->cd_start_offset), static_cast(eocd->cd_size), true /* read only */, debug_file_name); if (map == NULL) { archive->directory_map = NULL; return kMmapFailed; } archive->directory_map = map; archive->num_entries = eocd->num_records; archive->directory_offset = eocd->cd_start_offset; return 0; } /* * Find the zip Central Directory and memory-map it. * * On success, returns 0 after populating fields from the EOCD area: * directory_offset * directory_map * num_entries */ static int32_t MapCentralDirectory(int fd, 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 (Its size must be less than // 0xffffffff bytes). off64_t file_length = lseek64(fd, 0, SEEK_END); if (file_length == -1) { ALOGV("Zip: lseek on fd %d failed", fd); return kInvalidFile; } if (file_length > (off64_t) 0xffffffff) { 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. */ off64_t read_amount = kMaxEOCDSearch; if (file_length < read_amount) { read_amount = file_length; } uint8_t* scan_buffer = reinterpret_cast(malloc(read_amount)); int32_t result = MapCentralDirectory0(fd, debug_file_name, archive, file_length, read_amount, scan_buffer); free(scan_buffer); return result; } /* * Parses the Zip archive's Central Directory. Allocates and populates the * hash table. * * Returns 0 on success. */ static int32_t ParseZipArchive(ZipArchive* archive) { int32_t result = -1; const uint8_t* const cd_ptr = (const uint8_t*) archive->directory_map->getDataPtr(); const size_t cd_length = archive->directory_map->getDataLength(); const uint16_t num_entries = archive->num_entries; /* * Create hash table. We have a minimum 75% load factor, possibly as * low as 50% after we round off to a power of 2. There must be at * least one unused entry to avoid an infinite loop during creation. */ archive->hash_table_size = RoundUpPower2(1 + (num_entries * 4) / 3); archive->hash_table = (ZipEntryName*) calloc(archive->hash_table_size, sizeof(ZipEntryName)); /* * 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 (uint16_t i = 0; i < num_entries; i++) { const CentralDirectoryRecord* cdr = reinterpret_cast(ptr); if (cdr->record_signature != CentralDirectoryRecord::kSignature) { ALOGW("Zip: missed a central dir sig (at %" PRIu16 ")", i); goto bail; } if (ptr + sizeof(CentralDirectoryRecord) > cd_end) { ALOGW("Zip: ran off the end (at %" PRIu16 ")", i); goto bail; } const off64_t local_header_offset = cdr->local_file_header_offset; if (local_header_offset >= archive->directory_offset) { ALOGW("Zip: bad LFH offset %" PRId64 " at entry %" PRIu16, (int64_t)local_header_offset, i); goto bail; } 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; /* add the CDE filename to the hash table */ const uint8_t* file_name = ptr + sizeof(CentralDirectoryRecord); ZipEntryName entry_name; entry_name.name = file_name; entry_name.name_length = file_name_length; const int add_result = AddToHash(archive->hash_table, archive->hash_table_size, entry_name); if (add_result) { ALOGW("Zip: Error adding entry to hash table %d", add_result); result = add_result; goto bail; } 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 %" PRIu16, ptr - cd_ptr, cd_length, i); goto bail; } } ALOGV("+++ zip good scan %" PRIu16 " entries", num_entries); result = 0; bail: return result; } static int32_t OpenArchiveInternal(ZipArchive* archive, const char* debug_file_name) { int32_t result = -1; if ((result = MapCentralDirectory(archive->fd, debug_file_name, archive))) { return result; } if ((result = ParseZipArchive(archive))) { return result; } return 0; } int32_t OpenArchiveFd(int fd, const char* debug_file_name, ZipArchiveHandle* handle) { ZipArchive* archive = new ZipArchive(fd); *handle = archive; return OpenArchiveInternal(archive, debug_file_name); } int32_t OpenArchive(const char* fileName, ZipArchiveHandle* handle) { const int fd = open(fileName, O_RDONLY | O_BINARY, 0); ZipArchive* archive = new ZipArchive(fd); *handle = archive; if (fd < 0) { ALOGW("Unable to open '%s': %s", fileName, strerror(errno)); return kIoError; } return OpenArchiveInternal(archive, fileName); } /* * Close a ZipArchive, closing the file and freeing the contents. */ void CloseArchive(ZipArchiveHandle handle) { ZipArchive* archive = (ZipArchive*) handle; ALOGV("Closing archive %p", archive); delete archive; } static int32_t UpdateEntryFromDataDescriptor(int fd, ZipEntry *entry) { uint8_t ddBuf[sizeof(DataDescriptor) + sizeof(DataDescriptor::kOptSignature)]; ssize_t actual = TEMP_FAILURE_RETRY(read(fd, ddBuf, sizeof(ddBuf))); if (actual != sizeof(ddBuf)) { return kIoError; } const uint32_t ddSignature = *(reinterpret_cast(ddBuf)); const uint16_t offset = (ddSignature == DataDescriptor::kOptSignature) ? 4 : 0; const DataDescriptor* descriptor = reinterpret_cast(ddBuf + offset); entry->crc32 = descriptor->crc32; entry->compressed_length = descriptor->compressed_size; entry->uncompressed_length = descriptor->uncompressed_size; return 0; } // Attempts to read |len| bytes into |buf| at offset |off|. // // This method uses pread64 on platforms that support it and // lseek64 + read on platforms that don't. This implies that // callers should not rely on the |fd| offset being incremented // as a side effect of this call. static inline ssize_t ReadAtOffset(int fd, uint8_t* buf, size_t len, off64_t off) { #ifdef HAVE_PREAD return TEMP_FAILURE_RETRY(pread64(fd, buf, len, off)); #else // The only supported platform that doesn't support pread at the moment // is Windows. Only recent versions of windows support unix like forks, // and even there the semantics are quite different. if (lseek64(fd, off, SEEK_SET) != off) { ALOGW("Zip: failed seek to offset %" PRId64, off); return kIoError; } return TEMP_FAILURE_RETRY(read(fd, buf, len)); #endif // HAVE_PREAD } static int32_t FindEntry(const ZipArchive* archive, const int ent, ZipEntry* data) { const uint16_t nameLen = archive->hash_table[ent].name_length; // 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* ptr = archive->hash_table[ent].name; ptr -= sizeof(CentralDirectoryRecord); // This is the base of our mmapped region, we have to sanity check that // the name that's in the hash table is a pointer to a location within // this mapped region. const uint8_t* base_ptr = reinterpret_cast( archive->directory_map->getDataPtr()); if (ptr < base_ptr || ptr > base_ptr + archive->directory_map->getDataLength()) { ALOGW("Zip: Invalid entry pointer"); return kInvalidOffset; } const CentralDirectoryRecord *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 sanity 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_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. const off64_t local_header_offset = cdr->local_file_header_offset; 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)]; ssize_t actual = ReadAtOffset(archive->fd, lfh_buf, sizeof(lfh_buf), local_header_offset); if (actual != sizeof(lfh_buf)) { ALOGW("Zip: failed reading lfh name from offset %" PRId64, (int64_t)local_header_offset); return kIoError; } const LocalFileHeader *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; } // Paranoia: Match the values specified in the local file header // to those specified in the central directory. 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 {%" PRIu32 ", %" PRIu32 ", %" PRIx32 "}, was {%" PRIu32 ", %" PRIu32 ", %" 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; } // Check that the local file header name matches the declared // name in the central directory. if (lfh->file_name_length == nameLen) { const off64_t name_offset = local_header_offset + sizeof(LocalFileHeader); if (name_offset + lfh->file_name_length >= cd_offset) { ALOGW("Zip: Invalid declared length"); return kInvalidOffset; } uint8_t* name_buf = (uint8_t*) malloc(nameLen); ssize_t actual = ReadAtOffset(archive->fd, name_buf, nameLen, name_offset); if (actual != nameLen) { ALOGW("Zip: failed reading lfh name from offset %" PRId64, (int64_t)name_offset); free(name_buf); return kIoError; } if (memcmp(archive->hash_table[ent].name, name_buf, nameLen)) { free(name_buf); return kInconsistentInformation; } free(name_buf); } else { ALOGW("Zip: lfh name did not match central directory."); return kInconsistentInformation; } 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", (int64_t)data_offset); return kInvalidOffset; } if ((off64_t)(data_offset + data->compressed_length) > cd_offset) { ALOGW("Zip: bad compressed length in zip (%" PRId64 " + %" PRIu32 " > %" PRId64 ")", (int64_t)data_offset, data->compressed_length, (int64_t)cd_offset); return kInvalidOffset; } if (data->method == kCompressStored && (off64_t)(data_offset + data->uncompressed_length) > cd_offset) { ALOGW("Zip: bad uncompressed length in zip (%" PRId64 " + %" PRIu32 " > %" PRId64 ")", (int64_t)data_offset, data->uncompressed_length, (int64_t)cd_offset); return kInvalidOffset; } data->offset = data_offset; return 0; } struct IterationHandle { uint32_t position; const uint8_t* prefix; uint16_t prefix_len; ZipArchive* archive; IterationHandle() : prefix(NULL), prefix_len(0) {} IterationHandle(const ZipEntryName& prefix_name) : prefix_len(prefix_name.name_length) { uint8_t* prefix_copy = new uint8_t[prefix_len]; memcpy(reinterpret_cast(prefix_copy), prefix_name.name, prefix_len * sizeof(uint8_t)); prefix = prefix_copy; } ~IterationHandle() { delete [] prefix; } }; int32_t StartIteration(ZipArchiveHandle handle, void** cookie_ptr, const ZipEntryName* optional_prefix) { ZipArchive* archive = (ZipArchive *) handle; if (archive == NULL || archive->hash_table == NULL) { ALOGW("Zip: Invalid ZipArchiveHandle"); return kInvalidHandle; } IterationHandle* cookie = optional_prefix != NULL ? new IterationHandle(*optional_prefix) : new IterationHandle(); cookie->position = 0; cookie->archive = archive; *cookie_ptr = cookie ; return 0; } void EndIteration(void* cookie) { delete reinterpret_cast(cookie); } int32_t FindEntry(const ZipArchiveHandle handle, const ZipEntryName& entryName, ZipEntry* data) { const ZipArchive* archive = (ZipArchive*) handle; if (entryName.name_length == 0) { ALOGW("Zip: Invalid filename %.*s", entryName.name_length, entryName.name); return kInvalidEntryName; } const int64_t ent = EntryToIndex(archive->hash_table, archive->hash_table_size, entryName); if (ent < 0) { ALOGV("Zip: Could not find entry %.*s", entryName.name_length, entryName.name); return ent; } return FindEntry(archive, ent, data); } int32_t Next(void* cookie, ZipEntry* data, ZipEntryName* name) { IterationHandle* handle = (IterationHandle *) cookie; if (handle == NULL) { return kInvalidHandle; } ZipArchive* archive = handle->archive; if (archive == NULL || archive->hash_table == NULL) { ALOGW("Zip: Invalid ZipArchiveHandle"); return kInvalidHandle; } const uint32_t currentOffset = handle->position; const uint32_t hash_table_length = archive->hash_table_size; const ZipEntryName *hash_table = archive->hash_table; for (uint32_t i = currentOffset; i < hash_table_length; ++i) { if (hash_table[i].name != NULL && (handle->prefix_len == 0 || (memcmp(handle->prefix, hash_table[i].name, handle->prefix_len) == 0))) { handle->position = (i + 1); const int error = FindEntry(archive, i, data); if (!error) { name->name = hash_table[i].name; name->name_length = hash_table[i].name_length; } return error; } } handle->position = 0; return kIterationEnd; } static int32_t InflateToFile(int fd, const ZipEntry* entry, uint8_t* begin, uint32_t length, uint64_t* crc_out) { int32_t result = -1; const uint32_t kBufSize = 32768; uint8_t read_buf[kBufSize]; uint8_t 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 = (Bytef*) write_buf; 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 = 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; } const uint32_t uncompressed_length = entry->uncompressed_length; uint32_t compressed_length = entry->compressed_length; uint32_t write_count = 0; do { /* read as much as we can */ if (zstream.avail_in == 0) { const ZD_TYPE getSize = (compressed_length > kBufSize) ? kBufSize : compressed_length; const ZD_TYPE actual = TEMP_FAILURE_RETRY(read(fd, read_buf, getSize)); if (actual != getSize) { ALOGW("Zip: inflate read failed (" ZD " vs " ZD ")", actual, getSize); result = kIoError; goto z_bail; } compressed_length -= getSize; zstream.next_in = read_buf; zstream.avail_in = getSize; } /* 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); result = kZlibError; goto z_bail; } /* 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; // The file might have declared a bogus length. if (write_size + write_count > length) { goto z_bail; } memcpy(begin + write_count, write_buf, write_size); write_count += write_size; zstream.next_out = write_buf; zstream.avail_out = kBufSize; } } while (zerr == Z_OK); assert(zerr == Z_STREAM_END); /* other errors should've been caught */ // stream.adler holds the crc32 value for such streams. *crc_out = zstream.adler; if (zstream.total_out != uncompressed_length || compressed_length != 0) { ALOGW("Zip: size mismatch on inflated file (%lu vs %" PRIu32 ")", zstream.total_out, uncompressed_length); result = kInconsistentInformation; goto z_bail; } result = 0; z_bail: inflateEnd(&zstream); /* free up any allocated structures */ return result; } int32_t ExtractToMemory(ZipArchiveHandle handle, ZipEntry* entry, uint8_t* begin, uint32_t size) { ZipArchive* archive = (ZipArchive*) handle; const uint16_t method = entry->method; off64_t data_offset = entry->offset; if (lseek64(archive->fd, data_offset, SEEK_SET) != data_offset) { ALOGW("Zip: lseek to data at %" PRId64 " failed", (int64_t)data_offset); return kIoError; } // this should default to kUnknownCompressionMethod. int32_t return_value = -1; uint64_t crc = 0; if (method == kCompressStored) { return_value = CopyFileToFile(archive->fd, begin, size, &crc); } else if (method == kCompressDeflated) { return_value = InflateToFile(archive->fd, entry, begin, size, &crc); } if (!return_value && entry->has_data_descriptor) { return_value = UpdateEntryFromDataDescriptor(archive->fd, entry); if (return_value) { return return_value; } } // TODO: Fix this check by passing the right flags to inflate2 so that // it calculates the CRC for us. if (entry->crc32 != crc && false) { ALOGW("Zip: crc mismatch: expected %" PRIu32 ", was %" PRIu64, entry->crc32, crc); return kInconsistentInformation; } return return_value; } int32_t ExtractEntryToFile(ZipArchiveHandle handle, ZipEntry* entry, int fd) { const int32_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 kIoError; } int result = TEMP_FAILURE_RETRY(ftruncate(fd, declared_length + current_offset)); if (result == -1) { ALOGW("Zip: unable to truncate file to %" PRId64 ": %s", (int64_t)(declared_length + current_offset), strerror(errno)); return kIoError; } // Don't attempt to map a region of length 0. We still need the // ftruncate() though, since the API guarantees that we will truncate // the file to the end of the uncompressed output. if (declared_length == 0) { return 0; } android::FileMap* map = MapFileSegment(fd, current_offset, declared_length, false, kTempMappingFileName); if (map == NULL) { return kMmapFailed; } const int32_t error = ExtractToMemory(handle, entry, reinterpret_cast(map->getDataPtr()), map->getDataLength()); map->release(); return error; } const char* ErrorCodeString(int32_t error_code) { if (error_code > kErrorMessageLowerBound && error_code < kErrorMessageUpperBound) { return kErrorMessages[error_code * -1]; } return kErrorMessages[0]; } int GetFileDescriptor(const ZipArchiveHandle handle) { return ((ZipArchive*) handle)->fd; }