diff options
Diffstat (limited to 'libziparchive')
| -rw-r--r-- | libziparchive/Android.mk | 53 | ||||
| -rw-r--r-- | libziparchive/zip_archive.cc | 1074 | ||||
| -rw-r--r-- | libziparchive/zip_archive_test.cc | 46 |
3 files changed, 1173 insertions, 0 deletions
diff --git a/libziparchive/Android.mk b/libziparchive/Android.mk new file mode 100644 index 0000000..31c6051 --- /dev/null +++ b/libziparchive/Android.mk @@ -0,0 +1,53 @@ +# +# Copyright (C) 2013 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. + +LOCAL_PATH := $(call my-dir) +include $(CLEAR_VARS) + +source_files := \ + zip_archive.h \ + zip_archive.cc + +includes := external/zlib + +LOCAL_CPP_EXTENSION := .cc +LOCAL_SRC_FILES := ${source_files} + +LOCAL_STATIC_LIBRARIES := libz +LOCAL_MODULE:= libziparchive + +LOCAL_C_INCLUDES += ${includes} +include $(BUILD_STATIC_LIBRARY) + +include $(CLEAR_VARS) +LOCAL_MODULE := libziparchive +LOCAL_CPP_EXTENSION := .cc +LOCAL_SRC_FILES := ${source_files} +LOCAL_C_INCLUDES += ${includes} + +LOCAL_STATIC_LIBRARIES := libz +LOCAL_MODULE:= libziparchive-host +include $(BUILD_HOST_STATIC_LIBRARY) + +include $(CLEAR_VARS) +LOCAL_MODULE := ziparchive-tests +LOCAL_CPP_EXTENSION := .cc +LOCAL_CFLAGS += \ + -DGTEST_OS_LINUX_ANDROID \ + -DGTEST_HAS_STD_STRING +LOCAL_SRC_FILES := zip_archive_test.cc +LOCAL_LDFLAGS := -llog +LOCAL_STATIC_LIBRARIES := libziparchive libz libgtest libgtest_main +include $(BUILD_NATIVE_TEST) diff --git a/libziparchive/zip_archive.cc b/libziparchive/zip_archive.cc new file mode 100644 index 0000000..83b7c5b --- /dev/null +++ b/libziparchive/zip_archive.cc @@ -0,0 +1,1074 @@ +/* + * 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 "ziparchive/zip_archive.h" + +#include <zlib.h> + +#include <assert.h> +#include <errno.h> +#include <limits.h> +#include <log/log.h> +#include <fcntl.h> +#include <stdlib.h> +#include <string.h> +#include <sys/mman.h> +#include <unistd.h> + +#include <JNIHelp.h> // TEMP_FAILURE_RETRY may or may not be in unistd + +// This is for windows. If we don't open a file in binary mode, weirds +// things will happen. +#ifndef O_BINARY +#define O_BINARY 0 +#endif + +/* + * Zip file constants. + */ +static const uint32_t kEOCDSignature = 0x06054b50; +static const uint32_t kEOCDLen = 2; +static const uint32_t kEOCDNumEntries = 8; // offset to #of entries in file +static const uint32_t kEOCDSize = 12; // size of the central directory +static const uint32_t kEOCDFileOffset = 16; // offset to central directory + +static const uint32_t kMaxCommentLen = 65535; // longest possible in ushort +static const uint32_t kMaxEOCDSearch = (kMaxCommentLen + kEOCDLen); + +static const uint32_t kLFHSignature = 0x04034b50; +static const uint32_t kLFHLen = 30; // excluding variable-len fields +static const uint32_t kLFHGPBFlags = 6; // general purpose bit flags +static const uint32_t kLFHCRC = 14; // offset to CRC +static const uint32_t kLFHCompLen = 18; // offset to compressed length +static const uint32_t kLFHUncompLen = 22; // offset to uncompressed length +static const uint32_t kLFHNameLen = 26; // offset to filename length +static const uint32_t kLFHExtraLen = 28; // offset to extra length + +static const uint32_t kCDESignature = 0x02014b50; +static const uint32_t kCDELen = 46; // excluding variable-len fields +static const uint32_t kCDEMethod = 10; // offset to compression method +static const uint32_t kCDEModWhen = 12; // offset to modification timestamp +static const uint32_t kCDECRC = 16; // offset to entry CRC +static const uint32_t kCDECompLen = 20; // offset to compressed length +static const uint32_t kCDEUncompLen = 24; // offset to uncompressed length +static const uint32_t kCDENameLen = 28; // offset to filename length +static const uint32_t kCDEExtraLen = 30; // offset to extra length +static const uint32_t kCDECommentLen = 32; // offset to comment length +static const uint32_t kCDELocalOffset = 42; // offset to local hdr + +static const uint32_t kDDOptSignature = 0x08074b50; // *OPTIONAL* data descriptor signature +static const uint32_t kDDSignatureLen = 4; +static const uint32_t kDDLen = 12; +static const uint32_t kDDMaxLen = 16; // max of 16 bytes with a signature, 12 bytes without +static const uint32_t kDDCrc32 = 0; // offset to crc32 +static const uint32_t kDDCompLen = 4; // offset to compressed length +static const uint32_t kDDUncompLen = 8; // offset to uncompressed length + +static const uint32_t kGPBDDFlagMask = 0x0008; // mask value that signifies that the entry has a DD + +static const uint32_t kMaxErrorLen = 1024; + +static const char* kErrorMessages[] = { + "Unknown return code.", + "I/O Error", + "Zlib error", + "Invalid file", + "Invalid handle", + "Duplicate entries in archive", + "Empty archive", + "Entry not found", + "Invalid offset", + "Inconsistent information", + "Invalid entry name", + "Iteration ended", +}; + +static const int32_t kErrorMessageUpperBound = 0; + +// An I/O related system call (read, lseek, ftruncate, map) failed. +static const int32_t kIoError = -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; + +static const int32_t kIterationEnd = -12; + +static const int32_t kErrorMessageLowerBound = -13; + + +#ifdef PAGE_SHIFT +#define SYSTEM_PAGE_SIZE (1 << PAGE_SHIFT) +#else +#define SYSTEM_PAGE_SIZE 4096 +#endif + +struct MemMapping { + uint8_t* addr; // Start of data + size_t length; // Length of data + + uint8_t* base_address; // page-aligned base address + size_t base_length; // length of mapping +}; + +/* + * 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 */ + int fd; + + /* mapped central directory area */ + off64_t directory_offset; + MemMapping 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; +}; + +// Returns 0 on success and negative values on failure. +static int32_t MapFileSegment(const int fd, const off64_t start, const size_t length, + const int prot, const int flags, MemMapping *mapping) { + /* adjust to be page-aligned */ + const int adjust = start % SYSTEM_PAGE_SIZE; + const off64_t actual_start = start - adjust; + const off64_t actual_length = length + adjust; + + void* map_addr = mmap(NULL, actual_length, prot, flags, fd, actual_start); + if (map_addr == MAP_FAILED) { + ALOGW("mmap(%llx, R, FILE|SHARED, %d, %llx) failed: %s", + actual_length, fd, actual_start, strerror(errno)); + return kIoError; + } + + mapping->base_address = (uint8_t*) map_addr; + mapping->base_length = actual_length; + mapping->addr = (uint8_t*) map_addr + adjust; + mapping->length = length; + + ALOGV("mmap seg (st=%d ln=%d): b=%p bl=%d ad=%p ln=%d", + start, length, mapping->base_address, mapping->base_length, + mapping->addr, mapping->length); + + return 0; +} + +static void ReleaseMappedSegment(MemMapping* map) { + if (map->base_address == 0 || map->base_length == 0) { + return; + } + + if (munmap(map->base_address, map->base_length) < 0) { + ALOGW("munmap(%p, %d) failed: %s", + map->base_address, map->base_length, strerror(errno)); + } else { + ALOGV("munmap(%p, %d) succeeded", map->base_address, map->base_length); + } +} + +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 (%d vs %zd)", + (int) 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 char* str, uint16_t len) { + uint32_t hash = 0; + + 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 char* name, uint16_t length) { + const uint32_t hash = ComputeHash(name, length); + + // 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 == length && + memcmp(hash_table[ent].name, name, length) == 0) { + return ent; + } + + ent = (ent + 1) & (hash_table_size - 1); + } + + ALOGV("Zip: Unable to find entry %.*s", name_length, 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 char* name, uint16_t length) { + const uint64_t hash = ComputeHash(name, length); + 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 == length && + memcmp(hash_table[ent].name, name, length) == 0) { + // We've found a duplicate entry. We don't accept it + ALOGW("Zip: Found duplicate entry %.*s", length, name); + return kDuplicateEntry; + } + ent = (ent + 1) & (hash_table_size - 1); + } + + hash_table[ent].name = name; + hash_table[ent].name_length = length; + return 0; +} + +/* + * Get 2 little-endian bytes. + */ +static uint16_t get2LE(const uint8_t* src) { + return src[0] | (src[1] << 8); +} + +/* + * Get 4 little-endian bytes. + */ +static uint32_t get4LE(const uint8_t* src) { + uint32_t result; + + result = src[0]; + result |= src[1] << 8; + result |= src[2] << 16; + result |= src[3] << 24; + + return result; +} + +static int32_t MapCentralDirectory0(int fd, const char* debug_file_name, + ZipArchive* archive, off64_t file_length, + uint32_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 %lld failed: %s", search_start, strerror(errno)); + return kIoError; + } + ssize_t actual = TEMP_FAILURE_RETRY(read(fd, scan_buffer, read_amount)); + if (actual != (ssize_t) read_amount) { + ALOGW("Zip: read %zd failed: %s", 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; + for (i = read_amount - kEOCDLen; i >= 0; i--) { + if (scan_buffer[i] == 0x50 && get4LE(&scan_buffer[i]) == kEOCDSignature) { + 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 uint8_t* eocd_ptr = scan_buffer + i; + + assert(eocd_offset < file_length); + + /* + * Grab the CD offset and size, and the number of entries in the + * archive. Verify that they look reasonable. Widen dir_size and + * dir_offset to the file offset type. + */ + const uint16_t num_entries = get2LE(eocd_ptr + kEOCDNumEntries); + const off64_t dir_size = get4LE(eocd_ptr + kEOCDSize); + const off64_t dir_offset = get4LE(eocd_ptr + kEOCDFileOffset); + + if (dir_offset + dir_size > eocd_offset) { + ALOGW("Zip: bad offsets (dir %lld, size %lld, eocd %lld)", + dir_offset, dir_size, eocd_offset); + return kInvalidOffset; + } + if (num_entries == 0) { + ALOGW("Zip: empty archive?"); + return kEmptyArchive; + } + + ALOGV("+++ num_entries=%d dir_size=%d dir_offset=%d", num_entries, dir_size, + dir_offset); + + /* + * It all looks good. Create a mapping for the CD, and set the fields + * in archive. + */ + const int32_t result = MapFileSegment(fd, dir_offset, dir_size, + PROT_READ, MAP_FILE | MAP_SHARED, + &(archive->directory_map)); + if (result) { + return result; + } + + archive->num_entries = num_entries; + archive->directory_offset = dir_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 %d", file_length); + return kInvalidFile; + } + + if (file_length < (int64_t) kEOCDLen) { + ALOGV("Zip: length %ld is too small to be zip", 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 < (off64_t) read_amount) { + read_amount = file_length; + } + + uint8_t* scan_buffer = (uint8_t*) 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* cd_ptr = (const uint8_t*) archive->directory_map.addr; + size_t cd_length = archive->directory_map.length; + 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* ptr = cd_ptr; + for (uint16_t i = 0; i < num_entries; i++) { + if (get4LE(ptr) != kCDESignature) { + ALOGW("Zip: missed a central dir sig (at %d)", i); + goto bail; + } + + if (ptr + kCDELen > cd_ptr + cd_length) { + ALOGW("Zip: ran off the end (at %d)", i); + goto bail; + } + + const off64_t local_header_offset = get4LE(ptr + kCDELocalOffset); + if (local_header_offset >= archive->directory_offset) { + ALOGW("Zip: bad LFH offset %lld at entry %d", local_header_offset, i); + goto bail; + } + + const uint16_t file_name_length = get2LE(ptr + kCDENameLen); + const uint16_t extra_length = get2LE(ptr + kCDEExtraLen); + const uint16_t comment_length = get2LE(ptr + kCDECommentLen); + + /* add the CDE filename to the hash table */ + const int add_result = AddToHash(archive->hash_table, + archive->hash_table_size, (const char*) ptr + kCDELen, file_name_length); + if (add_result) { + ALOGW("Zip: Error adding entry to hash table %d", add_result); + result = add_result; + goto bail; + } + + ptr += kCDELen + file_name_length + extra_length + comment_length; + if ((size_t)(ptr - cd_ptr) > cd_length) { + ALOGW("Zip: bad CD advance (%d vs %zd) at entry %d", + (int) (ptr - cd_ptr), cd_length, i); + goto bail; + } + } + ALOGV("+++ zip good scan %d 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 = (ZipArchive*) malloc(sizeof(ZipArchive)); + memset(archive, 0, sizeof(*archive)); + *handle = archive; + + archive->fd = fd; + + return OpenArchiveInternal(archive, debug_file_name); +} + +int32_t OpenArchive(const char* fileName, ZipArchiveHandle* handle) { + ZipArchive* archive = (ZipArchive*) malloc(sizeof(ZipArchive)); + memset(archive, 0, sizeof(*archive)); + *handle = archive; + + const int fd = open(fileName, O_RDONLY | O_BINARY, 0); + if (fd < 0) { + ALOGW("Unable to open '%s': %s", fileName, strerror(errno)); + return kIoError; + } else { + archive->fd = fd; + } + + 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); + + if (archive->fd >= 0) { + close(archive->fd); + } + + ReleaseMappedSegment(&archive->directory_map); + free(archive->hash_table); + + /* ensure nobody tries to use the ZipArchive after it's closed */ + archive->directory_offset = -1; + archive->fd = -1; + archive->num_entries = -1; + archive->hash_table_size = -1; + archive->hash_table = NULL; +} + +static int32_t UpdateEntryFromDataDescriptor(int fd, + ZipEntry *entry) { + uint8_t ddBuf[kDDMaxLen]; + ssize_t actual = TEMP_FAILURE_RETRY(read(fd, ddBuf, sizeof(ddBuf))); + if (actual != sizeof(ddBuf)) { + return kIoError; + } + + const uint32_t ddSignature = get4LE(ddBuf); + uint16_t ddOffset = 0; + if (ddSignature == kDDOptSignature) { + ddOffset = 4; + } + + entry->crc32 = get4LE(ddBuf + ddOffset + kDDCrc32); + entry->compressed_length = get4LE(ddBuf + ddOffset + kDDCompLen); + entry->uncompressed_length = get4LE(ddBuf + ddOffset + kDDUncompLen); + + 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 %lld", name_offset); + 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; + const char* name = archive->hash_table[ent].name; + + // 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 unsigned char* ptr = (const unsigned char*) name; + ptr -= kCDELen; + + // 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 unsigned char* base_ptr = (const unsigned char*) + archive->directory_map.addr; + if (ptr < base_ptr || ptr > base_ptr + archive->directory_map.length) { + ALOGW("Zip: Invalid entry pointer"); + return kInvalidOffset; + } + + // 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 = get2LE(ptr + kCDEMethod); + data->mod_time = get4LE(ptr + kCDEModWhen); + data->crc32 = get4LE(ptr + kCDECRC); + data->compressed_length = get4LE(ptr + kCDECompLen); + data->uncompressed_length = get4LE(ptr + kCDEUncompLen); + + // 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 = get4LE(ptr + kCDELocalOffset); + if (local_header_offset + (off64_t) kLFHLen >= cd_offset) { + ALOGW("Zip: bad local hdr offset in zip"); + return kInvalidOffset; + } + + uint8_t lfh_buf[kLFHLen]; + 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 %lld", local_header_offset); + return kIoError; + } + + if (get4LE(lfh_buf) != kLFHSignature) { + ALOGW("Zip: didn't find signature at start of lfh, offset=%lld", + local_header_offset); + return kInvalidOffset; + } + + // Paranoia: Match the values specified in the local file header + // to those specified in the central directory. + const uint16_t lfhGpbFlags = get2LE(lfh_buf + kLFHGPBFlags); + const uint16_t lfhNameLen = get2LE(lfh_buf + kLFHNameLen); + const uint16_t lfhExtraLen = get2LE(lfh_buf + kLFHExtraLen); + + if ((lfhGpbFlags & kGPBDDFlagMask) == 0) { + const uint32_t lfhCrc = get4LE(lfh_buf + kLFHCRC); + const uint32_t lfhCompLen = get4LE(lfh_buf + kLFHCompLen); + const uint32_t lfhUncompLen = get4LE(lfh_buf + kLFHUncompLen); + + data->has_data_descriptor = 0; + if (data->compressed_length != lfhCompLen || data->uncompressed_length != lfhUncompLen + || data->crc32 != lfhCrc) { + ALOGW("Zip: size/crc32 mismatch. expected {%d, %d, %x}, was {%d, %d, %x}", + data->compressed_length, data->uncompressed_length, data->crc32, + lfhCompLen, lfhUncompLen, lfhCrc); + return kInconsistentInformation; + } + } else { + data->has_data_descriptor = 1; + } + + // Check that the local file header name matches the declared + // name in the central directory. + if (lfhNameLen == nameLen) { + const off64_t name_offset = local_header_offset + kLFHLen; + if (name_offset + lfhNameLen >= 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 %lld", name_offset); + free(name_buf); + return kIoError; + } + + if (memcmp(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 + kLFHLen + lfhNameLen + lfhExtraLen; + if (data_offset >= cd_offset) { + ALOGW("Zip: bad data offset %lld in zip", (off64_t) data_offset); + return kInvalidOffset; + } + + if ((off64_t)(data_offset + data->compressed_length) > cd_offset) { + ALOGW("Zip: bad compressed length in zip (%lld + %zd > %lld)", + data_offset, data->compressed_length, cd_offset); + return kInvalidOffset; + } + + if (data->method == kCompressStored && + (off64_t)(data_offset + data->uncompressed_length) > cd_offset) { + ALOGW("Zip: bad uncompressed length in zip (%lld + %zd > %lld)", + data_offset, data->uncompressed_length, cd_offset); + return kInvalidOffset; + } + + data->offset = data_offset; + return 0; +} + +struct IterationHandle { + uint32_t position; + const char* prefix; + uint16_t prefix_len; + ZipArchive* archive; +}; + +int32_t StartIteration(ZipArchiveHandle handle, void** cookie_ptr, const char* prefix) { + ZipArchive* archive = (ZipArchive *) handle; + + if (archive == NULL || archive->hash_table == NULL) { + ALOGW("Zip: Invalid ZipArchiveHandle"); + return kInvalidHandle; + } + + IterationHandle* cookie = (IterationHandle*) malloc(sizeof(IterationHandle)); + cookie->position = 0; + cookie->prefix = prefix; + cookie->archive = archive; + if (prefix != NULL) { + cookie->prefix_len = strlen(prefix); + } + + *cookie_ptr = cookie ; + return 0; +} + +int32_t FindEntry(const ZipArchiveHandle handle, const char* entryName, + ZipEntry* data) { + const ZipArchive* archive = (ZipArchive*) handle; + const int nameLen = strlen(entryName); + if (nameLen == 0 || nameLen > 65535) { + ALOGW("Zip: Invalid filename %s", entryName); + return kInvalidEntryName; + } + + const int64_t ent = EntryToIndex(archive->hash_table, + archive->hash_table_size, entryName, nameLen); + + if (ent < 0) { + ALOGW("Zip: Could not find entry %.*s", nameLen, entryName); + 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 == NULL || + (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 ssize_t getSize = (compressed_length > kBufSize) ? kBufSize : compressed_length; + const ssize_t actual = TEMP_FAILURE_RETRY(read(fd, read_buf, getSize)); + if (actual != getSize) { + ALOGW("Zip: inflate read failed (%d 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 (%ld vs %zd)", + 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 %lld failed", (off64_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 %u, was %llu", 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; + + int result = TEMP_FAILURE_RETRY(ftruncate(fd, declared_length)); + if (result == -1) { + ALOGW("Zip: unable to truncate file to %ud", declared_length); + return kIoError; + } + + MemMapping mapping; + int32_t error = MapFileSegment(fd, 0, declared_length, + PROT_READ | PROT_WRITE, + MAP_FILE | MAP_SHARED, + &mapping); + if (error) { + return error; + } + + error = ExtractToMemory(handle, entry, mapping.addr, + mapping.length); + ReleaseMappedSegment(&mapping); + 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; +} + diff --git a/libziparchive/zip_archive_test.cc b/libziparchive/zip_archive_test.cc new file mode 100644 index 0000000..ea2d827 --- /dev/null +++ b/libziparchive/zip_archive_test.cc @@ -0,0 +1,46 @@ +/* + * Copyright (C) 2013 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. + */ + +#include "ziparchive/zip_archive.h" + +#include <stdio.h> +#include <gtest/gtest.h> + +TEST(ziparchive, open) { + // Ignore this test, it's just a simple test involving + // the framework jar. + ZipArchiveHandle handle; + void* iterationCookie; + + ASSERT_EQ(0, OpenArchive("/sdcard/test.jar", &handle)); + ASSERT_EQ(0, StartIteration(handle, &iterationCookie, NULL)); + + ZipEntry data; + ZipEntryName name; + int ctr = 0; + while (Next(iterationCookie, &data, &name) == 0) { + printf("Found %.*s\n", name.name_length, name.name); + ctr++; + } + + ASSERT_EQ(2245, ctr); + + ASSERT_EQ(0, FindEntry(handle, "java/sql/Clob.class", &data)); + ASSERT_EQ(-1, FindEntry(handle, "java/sql/Slob.class", &data)); + + CloseArchive(&handle); +} + |