Magisk/app/src/main/jni/zipadjust.c
2017-04-26 00:59:56 +08:00

283 lines
9.9 KiB
C

#include <stdlib.h>
#include <stdio.h>
#include <zlib.h>
#include <string.h>
#include "zipadjust.h"
size_t insize = 0, outsize = 0, alloc = 0;
unsigned char *fin = NULL, *fout = NULL;
#pragma pack(1)
struct local_header_struct {
uint32_t signature;
uint16_t extract_version;
uint16_t flags;
uint16_t compression_method;
uint16_t last_modified_time;
uint16_t last_modified_date;
uint32_t crc32;
uint32_t size_compressed;
uint32_t size_uncompressed;
uint16_t length_filename;
uint16_t length_extra;
// filename
// extra
};
typedef struct local_header_struct local_header_t;
#pragma pack(1)
struct data_descriptor_struct {
uint32_t signature;
uint32_t crc32;
uint32_t size_compressed;
uint32_t size_uncompressed;
};
typedef struct data_descriptor_struct data_descriptor_t;
#pragma pack(1)
struct central_header_struct {
uint32_t signature;
uint16_t version_made;
uint16_t version_needed;
uint16_t flags;
uint16_t compression_method;
uint16_t last_modified_time;
uint16_t last_modified_date;
uint32_t crc32;
uint32_t size_compressed;
uint32_t size_uncompressed;
uint16_t length_filename;
uint16_t length_extra;
uint16_t length_comment;
uint16_t disk_start;
uint16_t attr_internal;
uint32_t attr_external;
uint32_t offset;
// filename
// extra
// comment
};
typedef struct central_header_struct central_header_t;
#pragma pack(1)
struct central_footer_struct {
uint32_t signature;
uint16_t disk_number;
uint16_t disk_number_central_directory;
uint16_t central_directory_entries_this_disk;
uint16_t central_directory_entries_total;
uint32_t central_directory_size;
uint32_t central_directory_offset;
uint16_t length_comment;
// comment
};
typedef struct central_footer_struct central_footer_t;
#define MAGIC_LOCAL_HEADER 0x04034b50
#define MAGIC_DATA_DESCRIPTOR 0x08074b50
#define MAGIC_CENTRAL_HEADER 0x02014b50
#define MAGIC_CENTRAL_FOOTER 0x06054b50
static int xerror(char* message) {
LOGE("%s\n", message);
return 0;
}
static int xseekread(off_t offset, void* buf, size_t bytes) {
memcpy(buf, fin + offset, bytes);
return 1;
}
static int xseekwrite(off_t offset, const void* buf, size_t bytes) {
if (offset + bytes > outsize) outsize = offset + bytes;
if (outsize > alloc) {
fout = realloc(fout, outsize);
alloc = outsize;
}
memcpy(fout + offset, buf, bytes);
return 1;
}
static int xfilecopy(off_t offsetIn, off_t offsetOut, size_t bytes) {
unsigned int CHUNK = 256 * 1024;
unsigned char* buf = malloc(CHUNK);
if (buf == NULL) return xerror("malloc failed");
size_t left = bytes;
while (left > 0) {
size_t wanted = (left < CHUNK) ? left : CHUNK;
xseekread(offsetIn, buf, wanted);
xseekwrite(offsetOut, buf, wanted);
offsetIn += wanted;
offsetOut += wanted;
left -= wanted;
}
free(buf);
return 1;
}
static int xdecompress(off_t offsetIn, off_t offsetOut, size_t bytes) {
unsigned int CHUNK = 256 * 1024;
int ret;
unsigned have;
z_stream strm;
unsigned char in[CHUNK];
unsigned char out[CHUNK];
strm.zalloc = Z_NULL;
strm.zfree = Z_NULL;
strm.opaque = Z_NULL;
strm.avail_in = 0;
strm.next_in = Z_NULL;
ret = inflateInit2(&strm, -15);
if (ret != Z_OK) return xerror("ret != Z_OK");
do {
strm.avail_in = insize - offsetIn;
if (strm.avail_in == 0) break;
strm.avail_in = (strm.avail_in > CHUNK) ? CHUNK : strm.avail_in;
xseekread(offsetIn, in, strm.avail_in);
strm.next_in = in;
offsetIn += strm.avail_in;
do {
strm.avail_out = CHUNK;
strm.next_out = out;
ret = inflate(&strm, Z_NO_FLUSH);
if (ret == Z_STREAM_ERROR) return xerror("Stream error");
switch (ret) {
case Z_NEED_DICT:
ret = Z_DATA_ERROR;
case Z_DATA_ERROR:
case Z_MEM_ERROR:
(void)inflateEnd(&strm);
return xerror("DICT/DATA/MEM error");
}
have = CHUNK - strm.avail_out;
xseekwrite(offsetOut, out, have);
offsetOut += have;
} while (strm.avail_out == 0);
} while (ret != Z_STREAM_END);
(void)inflateEnd(&strm);
return ret == Z_STREAM_END ? 1 : 0;
}
int zipadjust(int decompress) {
int ok = 0;
char filename[1024];
central_footer_t central_footer;
uint32_t central_directory_in_position = 0;
uint32_t central_directory_in_size = 0;
uint32_t central_directory_out_size = 0;
int i;
for (i = insize - 4; i >= 0; i--) {
uint32_t magic = 0;
if (!xseekread(i, &magic, sizeof(uint32_t))) return 0;
if (magic == MAGIC_CENTRAL_FOOTER) {
LOGD("central footer @ %08X\n", i);
if (!xseekread(i, &central_footer, sizeof(central_footer_t))) return 0;
central_header_t central_header;
if (!xseekread(central_footer.central_directory_offset, &central_header, sizeof(central_header_t))) return 0;
if ( central_header.signature == MAGIC_CENTRAL_HEADER ) {
central_directory_in_position = central_footer.central_directory_offset;
central_directory_in_size = insize - central_footer.central_directory_offset;
LOGD("central header @ %08X (%d)\n", central_footer.central_directory_offset, central_footer.central_directory_size);
break;
}
}
}
if (central_directory_in_position == 0) return 0;
unsigned char* central_directory_in = (unsigned char*)malloc(central_directory_in_size);
unsigned char* central_directory_out = (unsigned char*)malloc(central_directory_in_size);
if (!xseekread(central_directory_in_position, central_directory_in, central_directory_in_size)) return 0;
memset(central_directory_out, 0, central_directory_in_size);
fout = (unsigned char*) malloc(insize);
alloc = insize;
uintptr_t central_directory_in_index = 0;
uintptr_t central_directory_out_index = 0;
central_header_t* central_header = NULL;
uint32_t out_index = 0;
while (1) {
central_header = (central_header_t*)&central_directory_in[central_directory_in_index];
if (central_header->signature != MAGIC_CENTRAL_HEADER) break;
filename[central_header->length_filename] = (char)0;
memcpy(filename, &central_directory_in[central_directory_in_index + sizeof(central_header_t)], central_header->length_filename);
LOGD("%s (%d --> %d) [%08X] (%d)\n", filename, central_header->size_uncompressed, central_header->size_compressed, central_header->crc32, central_header->length_extra + central_header->length_comment);
local_header_t local_header;
if (!xseekread(central_header->offset, &local_header, sizeof(local_header_t))) return 0;
// save and update to next index before we clobber the data
uint16_t compression_method_old = central_header->compression_method;
uint32_t size_compressed_old = central_header->size_compressed;
uint32_t offset_old = central_header->offset;
uint32_t length_extra_old = central_header->length_extra;
central_directory_in_index += sizeof(central_header_t) + central_header->length_filename + central_header->length_extra + central_header->length_comment;
// copying, rewriting, and correcting local and central headers so all the information matches, and no data descriptors are necessary
central_header->offset = out_index;
central_header->flags = central_header->flags & !8;
if (decompress && (compression_method_old == 8)) {
central_header->compression_method = 0;
central_header->size_compressed = central_header->size_uncompressed;
}
central_header->length_extra = 0;
central_header->length_comment = 0;
local_header.compression_method = central_header->compression_method;
local_header.flags = central_header->flags;
local_header.crc32 = central_header->crc32;
local_header.size_uncompressed = central_header->size_uncompressed;
local_header.size_compressed = central_header->size_compressed;
local_header.length_extra = 0;
if (!xseekwrite(out_index, &local_header, sizeof(local_header_t))) return 0;
out_index += sizeof(local_header_t);
if (!xseekwrite(out_index, &filename[0], central_header->length_filename)) return 0;
out_index += central_header->length_filename;
if (decompress && (compression_method_old == 8)) {
if (!xdecompress(offset_old + sizeof(local_header_t) + central_header->length_filename + length_extra_old, out_index, size_compressed_old)) return 0;
} else {
if (!xfilecopy(offset_old + sizeof(local_header_t) + central_header->length_filename + length_extra_old, out_index, size_compressed_old)) return 0;
}
out_index += local_header.size_compressed;
memcpy(&central_directory_out[central_directory_out_index], central_header, sizeof(central_header_t) + central_header->length_filename);
central_directory_out_index += sizeof(central_header_t) + central_header->length_filename;
}
central_directory_out_size = central_directory_out_index;
central_footer.central_directory_size = central_directory_out_size;
central_footer.central_directory_offset = out_index;
central_footer.length_comment = 0;
if (!xseekwrite(out_index, central_directory_out, central_directory_out_size)) return 0;
out_index += central_directory_out_size;
if (!xseekwrite(out_index, &central_footer, sizeof(central_footer_t))) return 0;
LOGD("central header @ %08X (%d)\n", central_footer.central_directory_offset, central_footer.central_directory_size);
LOGD("central footer @ %08X\n", out_index);
ok = 1;
free(central_directory_in);
free(central_directory_out);
return ok;
}