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#include <stdlib.h>
#include <string.h>
#include "main.h"
#include "unzip.h"
#include "zlib.h"
#define HEADER_SIZE 30
#define CHUNK 65536
#define LE_READ16(buf) ((uint16_t)(((uint8_t *)(buf))[1] << 8 | ((uint8_t *)(buf))[0]))
#define LE_READ32(buf) ((uint32_t)(((uint8_t *)(buf))[3] << 24 | ((uint8_t *)(buf))[2] << 16 | ((uint8_t *)(buf))[1] << 8 | ((uint8_t *)(buf))[0]))
struct file_info {
uint32_t compressed_size;
int (*inflate)(FILE *zip, FILE *dest, size_t size);
char filename[MAX_PATH];
};
static int write_uncompressed(FILE *zip, FILE *dest, size_t size) {
uint8_t buf[CHUNK];
while (size) {
size_t wsize = MIN(size, CHUNK);
if (size != fread(buf, 1, wsize, zip)) {
return -1;
}
if (size != fwrite(buf, 1, wsize, zip)) {
return -1;
}
size -= wsize;
}
return 0;
}
static int write_inflate(FILE *zip, FILE *dest, size_t size) {
z_stream stream = {0};
size_t have = 0;
uint8_t in[CHUNK];
uint8_t out[CHUNK];
int ret = -1;
ret = inflateInit2(&stream, -MAX_WBITS);
if (ret != Z_OK)
return ret;
do {
size_t insize = MIN(size, CHUNK);
stream.avail_in = fread(in, 1, insize, zip);
if (ferror(zip)) {
(void)inflateEnd(&stream);
return Z_ERRNO;
}
if (!stream.avail_in)
break;
stream.next_in = in;
do {
stream.avail_out = CHUNK;
stream.next_out = out;
ret = inflate(&stream, Z_NO_FLUSH);
switch(ret) {
case Z_NEED_DICT:
ret = Z_DATA_ERROR;
case Z_DATA_ERROR:
case Z_MEM_ERROR:
(void)inflateEnd(&stream);
return ret;
}
have = CHUNK - stream.avail_out;
if (fwrite(out, 1, have, dest) != have || ferror(dest)) {
(void)inflateEnd(&stream);
return Z_ERRNO;
}
} while (stream.avail_out == 0);
size -= insize;
} while (size && ret != Z_STREAM_END);
(void)inflateEnd(&stream);
if (!size || ret == Z_STREAM_END) {
return Z_OK;
} else {
return Z_DATA_ERROR;
}
}
static int find_entry(FILE *zip, const char **extensions, struct file_info *info) {
int ret = -1;
uint8_t header[HEADER_SIZE];
uint32_t next = 0;
uint16_t file_name_size = 0;
char extension[10];
while(1) {
bool match = false;
if (next)
fseek(zip, next, SEEK_CUR);
if (HEADER_SIZE != fread(header, 1, HEADER_SIZE, zip))
break;
if (header[0] != 0x50 || header[1] != 0x4b || header[2] != 0x03 || header[3] != 0x04)
break;
if ((uint16_t)(header[6]) & 0x0008) {
PA_ERROR("Unsupported zip file\n");
break;
}
file_name_size = LE_READ16(&header[26]);
if (file_name_size >= MAX_PATH)
break;
if (file_name_size != fread(info->filename, 1, file_name_size, zip))
break;
info->filename[file_name_size] = '\0';
info->compressed_size = LE_READ32(&header[18]);
fseek(zip, LE_READ16(&header[28]), SEEK_CUR);
next = info->compressed_size;
for (int i = 0; extensions[i]; i++) {
snprintf(extension, 10, ".%s", extensions[i]);
if (has_suffix_i(info->filename, extension)) {
match = true;
break;
}
}
if (!match)
continue;
switch (LE_READ16(&header[8])) {
case 0: /* Uncompressed */
info->inflate = write_uncompressed;
case 8: /* DEFLATE */
info->inflate = write_inflate;
}
ret = 0;
break;
}
return ret;
}
int unzip_tmp(FILE *zip, const char **extensions, char *filename, size_t len) {
int ret = -1;
struct file_info info = {0};
FILE *dest = NULL;
if (!find_entry(zip, extensions, &info)) {
int fd = 0;
snprintf(filename, len, "/tmp/pa-XXXXXX%s", basename(info.filename));
fd = mkstemps(filename, strlen(info.filename));
dest = fdopen(fd, "w");
if (!dest) {
PA_ERROR("Error creating temporary file for decompression\n");
goto finish;
}
if (info.inflate(zip, dest, info.compressed_size)) {
PA_ERROR("Error decompressing file\n");
goto finish;
}
ret = 0;
}
finish:
if (dest)
fclose(dest);
return ret;
}
int unzip(FILE *zip, const char **extensions, FILE *dest) {
int ret = -1;
struct file_info info = {0};
if(!find_entry(zip, extensions, &info)) {
if (!info.inflate(zip, dest, info.compressed_size)) {
ret = 0;
} else {
PA_ERROR("Error decompressing file\n");
}
}
return ret;
}
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