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rufus/src/bled/decompress_unzip.c

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/*
* unzip implementation for Bled/busybox
*
* Copyright © 2015 Pete Batard <pete@akeo.ie>
* Based on mini unzip implementation for busybox © Ed Clark
* Loosely based on original busybox unzip applet © Laurence Anderson.
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
/* The following are not currently supported:
* - Store (uncompressed)
* - Zip64
*/
#include "libbb.h"
#include "bb_archive.h"
enum {
#if BB_BIG_ENDIAN
ZIP_FILEHEADER_MAGIC = 0x504b0304,
ZIP_CDF_MAGIC = 0x504b0102, /* central directory's file header */
ZIP_CDE_MAGIC = 0x504b0506, /* "end of central directory" record */
ZIP_DD_MAGIC = 0x504b0708,
#else
ZIP_FILEHEADER_MAGIC = 0x04034b50,
ZIP_CDF_MAGIC = 0x02014b50,
ZIP_CDE_MAGIC = 0x06054b50,
ZIP_DD_MAGIC = 0x08074b50,
#endif
};
#define ZIP_HEADER_LEN 26
PRAGMA_BEGIN_PACKED
typedef union {
uint8_t raw[ZIP_HEADER_LEN];
struct {
uint16_t version; /* 0-1 */
uint16_t zip_flags; /* 2-3 */
uint16_t method; /* 4-5 */
uint16_t modtime; /* 6-7 */
uint16_t moddate; /* 8-9 */
uint32_t crc32; /* 10-13 */
uint32_t cmpsize; /* 14-17 */
uint32_t ucmpsize; /* 18-21 */
uint16_t filename_len; /* 22-23 */
uint16_t extra_len; /* 24-25 */
} PACKED formatted;
} PACKED zip_header_t;
PRAGMA_END_PACKED
/* Check the offset of the last element, not the length. This leniency
* allows for poor packing, whereby the overall struct may be too long,
* even though the elements are all in the right place.
*/
struct BUG_zip_header_must_be_26_bytes {
char BUG_zip_header_must_be_26_bytes[
offsetof(zip_header_t, formatted.extra_len) + 2
== ZIP_HEADER_LEN ? 1 : -1];
};
#define FIX_ENDIANNESS_ZIP(zip_header) do { \
(zip_header).formatted.version = SWAP_LE16((zip_header).formatted.version ); \
(zip_header).formatted.method = SWAP_LE16((zip_header).formatted.method ); \
(zip_header).formatted.modtime = SWAP_LE16((zip_header).formatted.modtime ); \
(zip_header).formatted.moddate = SWAP_LE16((zip_header).formatted.moddate ); \
(zip_header).formatted.crc32 = SWAP_LE32((zip_header).formatted.crc32 ); \
(zip_header).formatted.cmpsize = SWAP_LE32((zip_header).formatted.cmpsize ); \
(zip_header).formatted.ucmpsize = SWAP_LE32((zip_header).formatted.ucmpsize ); \
(zip_header).formatted.filename_len = SWAP_LE16((zip_header).formatted.filename_len); \
(zip_header).formatted.extra_len = SWAP_LE16((zip_header).formatted.extra_len ); \
} while (0)
#define CDF_HEADER_LEN 42
PRAGMA_BEGIN_PACKED
typedef union {
uint8_t raw[CDF_HEADER_LEN];
struct {
/* uint32_t signature; 50 4b 01 02 */
uint16_t version_made_by; /* 0-1 */
uint16_t version_needed; /* 2-3 */
uint16_t cdf_flags; /* 4-5 */
uint16_t method; /* 6-7 */
uint16_t mtime; /* 8-9 */
uint16_t mdate; /* 10-11 */
uint32_t crc32; /* 12-15 */
uint32_t cmpsize; /* 16-19 */
uint32_t ucmpsize; /* 20-23 */
uint16_t file_name_length; /* 24-25 */
uint16_t extra_field_length; /* 26-27 */
uint16_t file_comment_length; /* 28-29 */
uint16_t disk_number_start; /* 30-31 */
uint16_t internal_file_attributes; /* 32-33 */
uint32_t external_file_attributes; /* 34-37 */
uint32_t relative_offset_of_local_header; /* 38-41 */
} PACKED formatted;
} cdf_header_t;
PRAGMA_END_PACKED
struct BUG_cdf_header_must_be_42_bytes {
char BUG_cdf_header_must_be_42_bytes[
offsetof(cdf_header_t, formatted.relative_offset_of_local_header) + 4
== CDF_HEADER_LEN ? 1 : -1];
};
#define FIX_ENDIANNESS_CDF(cdf_header) do { \
(cdf_header).formatted.crc32 = SWAP_LE32((cdf_header).formatted.crc32 ); \
(cdf_header).formatted.cmpsize = SWAP_LE32((cdf_header).formatted.cmpsize ); \
(cdf_header).formatted.ucmpsize = SWAP_LE32((cdf_header).formatted.ucmpsize ); \
(cdf_header).formatted.file_name_length = SWAP_LE16((cdf_header).formatted.file_name_length); \
(cdf_header).formatted.extra_field_length = SWAP_LE16((cdf_header).formatted.extra_field_length); \
(cdf_header).formatted.file_comment_length = SWAP_LE16((cdf_header).formatted.file_comment_length); \
IF_DESKTOP( \
(cdf_header).formatted.version_made_by = SWAP_LE16((cdf_header).formatted.version_made_by); \
(cdf_header).formatted.external_file_attributes = SWAP_LE32((cdf_header).formatted.external_file_attributes); \
) \
} while (0)
#define CDE_HEADER_LEN 16
PRAGMA_BEGIN_PACKED
typedef union {
uint8_t raw[CDE_HEADER_LEN];
struct {
/* uint32_t signature; 50 4b 05 06 */
uint16_t this_disk_no;
uint16_t disk_with_cdf_no;
uint16_t cdf_entries_on_this_disk;
uint16_t cdf_entries_total;
uint32_t cdf_size;
uint32_t cdf_offset;
/* uint16_t file_comment_length; */
/* .ZIP file comment (variable size) */
} PACKED formatted;
} cde_header_t;
PRAGMA_END_PACKED
struct BUG_cde_header_must_be_16_bytes {
char BUG_cde_header_must_be_16_bytes[
sizeof(cde_header_t) == CDE_HEADER_LEN ? 1 : -1];
};
#define FIX_ENDIANNESS_CDE(cde_header) do { \
(cde_header).formatted.cdf_offset = SWAP_LE32((cde_header).formatted.cdf_offset); \
} while (0)
#if ENABLE_DESKTOP
/* Seen in the wild:
* Self-extracting PRO2K3XP_32.exe contains 19078464 byte zip archive,
* where CDE was nearly 48 kbytes before EOF.
* (Surprisingly, it also apparently has *another* CDE structure
* closer to the end, with bogus cdf_offset).
* To make extraction work, bumped PEEK_FROM_END from 16k to 64k.
*/
#define PEEK_FROM_END (64*1024)
/* This value means that we failed to find CDF */
#define BAD_CDF_OFFSET ((uint32_t)0xffffffff)
/* NB: does not preserve file position! */
static uint32_t find_cdf_offset(void)
{
cde_header_t cde_header;
unsigned char *p;
off_t end;
unsigned char *buf = xzalloc(PEEK_FROM_END);
end = xlseek(zip_fd, 0, SEEK_END);
end -= PEEK_FROM_END;
if (end < 0)
end = 0;
xlseek(zip_fd, end, SEEK_SET);
full_read(zip_fd, buf, PEEK_FROM_END);
cde_header.formatted.cdf_offset = BAD_CDF_OFFSET;
p = buf;
while (p <= buf + PEEK_FROM_END - CDE_HEADER_LEN - 4) {
if (*p != 'P') {
p++;
continue;
}
if (*++p != 'K')
continue;
if (*++p != 5)
continue;
if (*++p != 6)
continue;
/* we found CDE! */
memcpy(cde_header.raw, p + 1, CDE_HEADER_LEN);
FIX_ENDIANNESS_CDE(cde_header);
/*
* I've seen .ZIP files with seemingly valid CDEs
* where cdf_offset points past EOF - ??
* Ignore such CDEs:
*/
if (cde_header.formatted.cdf_offset < end + (p - buf))
break;
cde_header.formatted.cdf_offset = BAD_CDF_OFFSET;
}
free(buf);
return cde_header.formatted.cdf_offset;
};
static uint32_t read_next_cdf(uint32_t cdf_offset, cdf_header_t *cdf_ptr)
{
off_t org;
org = xlseek(zip_fd, 0, SEEK_CUR);
if (!cdf_offset)
cdf_offset = find_cdf_offset();
if (cdf_offset != BAD_CDF_OFFSET) {
xlseek(zip_fd, cdf_offset + 4, SEEK_SET);
xread(zip_fd, cdf_ptr->raw, CDF_HEADER_LEN);
FIX_ENDIANNESS_CDF(*cdf_ptr);
cdf_offset += 4 + CDF_HEADER_LEN
+ cdf_ptr->formatted.file_name_length
+ cdf_ptr->formatted.extra_field_length
+ cdf_ptr->formatted.file_comment_length;
}
xlseek(zip_fd, org, SEEK_SET);
return cdf_offset;
};
#endif
static void unzip_skip(int zip_fd, off_t skip)
{
if (skip != 0)
if (lseek(zip_fd, skip, SEEK_CUR) == (off_t)-1)
bb_copyfd_exact_size(zip_fd, -1, skip);
}
IF_DESKTOP(long long) int FAST_FUNC unpack_zip_stream(transformer_state_t *xstate)
{
IF_DESKTOP(long long) int n = -EFAULT;
zip_header_t zip_header;
char *filename = NULL;
#if ENABLE_DESKTOP
uint32_t cdf_offset = 0;
#endif
while (1) {
uint32_t magic;
/* Check magic number */
safe_read(xstate->src_fd, &magic, 4);
/* Central directory? It's at the end, so exit */
if (magic == ZIP_CDF_MAGIC)
break;
#if ENABLE_DESKTOP
/* Data descriptor? It was a streaming file, go on */
if (magic == ZIP_DD_MAGIC) {
/* skip over duplicate crc32, cmpsize and ucmpsize */
unzip_skip(xstate->src_fd, 3 * 4);
continue;
}
#endif
if (magic != ZIP_FILEHEADER_MAGIC)
bb_error_msg_and_err("invalid zip magic %08X", (int)magic);
/* Read the file header */
safe_read(xstate->src_fd, zip_header.raw, ZIP_HEADER_LEN);
FIX_ENDIANNESS_ZIP(zip_header);
if (zip_header.formatted.method != 8) {
bb_error_msg_and_err("zip method method %d is not supported", zip_header.formatted.method);
}
#if !ENABLE_DESKTOP
if (zip_header.formatted.zip_flags & SWAP_LE16(0x0009)) {
bb_error_msg_and_err("zip flags 1 and 8 are not supported");
}
#else
if (zip_header.formatted.zip_flags & SWAP_LE16(0x0001)) {
/* 0x0001 - encrypted */
bb_error_msg_and_die("zip flag 1 (encryption) is not supported");
}
if (cdf_offset != BAD_CDF_OFFSET) {
cdf_header_t cdf_header;
cdf_offset = read_next_cdf(cdf_offset, &cdf_header);
/*
* Note: cdf_offset can become BAD_CDF_OFFSET after the above call.
*/
if (zip_header.formatted.zip_flags & SWAP_LE16(0x0008)) {
/* 0x0008 - streaming. [u]cmpsize can be reliably gotten
* only from Central Directory. See unzip_doc.txt
*/
zip_header.formatted.crc32 = cdf_header.formatted.crc32;
zip_header.formatted.cmpsize = cdf_header.formatted.cmpsize;
zip_header.formatted.ucmpsize = cdf_header.formatted.ucmpsize;
}
if ((cdf_header.formatted.version_made_by >> 8) == 3) {
/* This archive is created on Unix */
dir_mode = file_mode = (cdf_header.formatted.external_file_attributes >> 16);
}
}
if (cdf_offset == BAD_CDF_OFFSET
&& (zip_header.formatted.zip_flags & SWAP_LE16(0x0008))
) {
/* If it's a streaming zip, we _require_ CDF */
bb_error_msg_and_die("can't find file table");
}
#endif
/* Read filename */
filename = xzalloc(zip_header.formatted.filename_len + 1);
safe_read(xstate->src_fd, filename, zip_header.formatted.filename_len);
bb_printf("processing archive file '%s'", filename);
free(filename);
/* Skip extra header bytes */
unzip_skip(xstate->src_fd, zip_header.formatted.extra_len);
/* Method 8 - inflate */
xstate->bytes_in = zip_header.formatted.cmpsize;
n = inflate_unzip(xstate);
/* Validate decompression */
if (n >= 0) {
if (zip_header.formatted.ucmpsize != xstate->bytes_out)
bb_error_msg_and_err("bad length");
else if (zip_header.formatted.crc32 != (xstate->crc32 ^ 0xffffffffL))
bb_error_msg_and_err("crc error");
} else if (n != -ENOSPC) {
bb_error_msg_and_err("inflate error");
}
}
err:
if (n > 0)
return xstate->bytes_out;
else if (n == -ENOSPC)
return xstate->mem_output_size_max;
else
return n;
}