libarchive-3.0.3.2: c/archive_read_support_format_rar5.c
/*-
* Copyright (c) 2018 Grzegorz Antoniak (http://antoniak.org)
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "archive_platform.h"
#include "archive_endian.h"
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#include <time.h>
#ifdef HAVE_ZLIB_H
#include <zlib.h> /* crc32 */
#endif
#ifdef HAVE_LIMITS_H
#include <limits.h>
#endif
#include "archive.h"
#ifndef HAVE_ZLIB_H
#include "archive_crc32.h"
#endif
#include "archive_entry.h"
#include "archive_entry_locale.h"
#include "archive_ppmd7_private.h"
#include "archive_entry_private.h"
#ifdef HAVE_BLAKE2_H
#include <blake2.h>
#else
#include "archive_blake2.h"
#endif
/*#define CHECK_CRC_ON_SOLID_SKIP*/
/*#define DONT_FAIL_ON_CRC_ERROR*/
/*#define DEBUG*/
#define rar5_min(a, b) (((a) > (b)) ? (b) : (a))
#define rar5_max(a, b) (((a) > (b)) ? (a) : (b))
#define rar5_countof(X) ((const ssize_t) (sizeof(X) / sizeof(*X)))
#if defined DEBUG
#define DEBUG_CODE if(1)
#define LOG(...) do { printf("rar5: " __VA_ARGS__); puts(""); } while(0)
#else
#define DEBUG_CODE if(0)
#endif
/* Real RAR5 magic number is:
*
* 0x52, 0x61, 0x72, 0x21, 0x1a, 0x07, 0x01, 0x00
* "Rar!→•☺·\x00"
*
* Retrieved with `rar5_signature()` by XOR'ing it with 0xA1, because I don't
* want to put this magic sequence in each binary that uses libarchive, so
* applications that scan through the file for this marker won't trigger on
* this "false" one.
*
* The array itself is decrypted in `rar5_init` function. */
static unsigned char rar5_signature_xor[] = { 243, 192, 211, 128, 187, 166, 160, 161 };
static const size_t g_unpack_window_size = 0x20000;
/* These could have been static const's, but they aren't, because of
* Visual Studio. */
#define MAX_NAME_IN_CHARS 2048
#define MAX_NAME_IN_BYTES (4 * MAX_NAME_IN_CHARS)
struct file_header {
ssize_t bytes_remaining;
ssize_t unpacked_size;
int64_t last_offset; /* Used in sanity checks. */
int64_t last_size; /* Used in sanity checks. */
uint8_t solid : 1; /* Is this a solid stream? */
uint8_t service : 1; /* Is this file a service data? */
uint8_t eof : 1; /* Did we finish unpacking the file? */
uint8_t dir : 1; /* Is this file entry a directory? */
/* Optional time fields. */
uint64_t e_mtime;
uint64_t e_ctime;
uint64_t e_atime;
uint32_t e_unix_ns;
/* Optional hash fields. */
uint32_t stored_crc32;
uint32_t calculated_crc32;
uint8_t blake2sp[32];
blake2sp_state b2state;
char has_blake2;
/* Optional redir fields */
uint64_t redir_type;
uint64_t redir_flags;
ssize_t solid_window_size; /* Used in file format check. */
};
enum EXTRA {
EX_CRYPT = 0x01,
EX_HASH = 0x02,
EX_HTIME = 0x03,
EX_VERSION = 0x04,
EX_REDIR = 0x05,
EX_UOWNER = 0x06,
EX_SUBDATA = 0x07
};
#define REDIR_SYMLINK_IS_DIR 1
enum REDIR_TYPE {
REDIR_TYPE_NONE = 0,
REDIR_TYPE_UNIXSYMLINK = 1,
REDIR_TYPE_WINSYMLINK = 2,
REDIR_TYPE_JUNCTION = 3,
REDIR_TYPE_HARDLINK = 4,
REDIR_TYPE_FILECOPY = 5,
};
#define OWNER_USER_NAME 0x01
#define OWNER_GROUP_NAME 0x02
#define OWNER_USER_UID 0x04
#define OWNER_GROUP_GID 0x08
#define OWNER_MAXNAMELEN 256
enum FILTER_TYPE {
FILTER_DELTA = 0, /* Generic pattern. */
FILTER_E8 = 1, /* Intel x86 code. */
FILTER_E8E9 = 2, /* Intel x86 code. */
FILTER_ARM = 3, /* ARM code. */
FILTER_AUDIO = 4, /* Audio filter, not used in RARv5. */
FILTER_RGB = 5, /* Color palette, not used in RARv5. */
FILTER_ITANIUM = 6, /* Intel's Itanium, not used in RARv5. */
FILTER_PPM = 7, /* Predictive pattern matching, not used in
RARv5. */
FILTER_NONE = 8,
};
struct filter_info {
int type;
int channels;
int pos_r;
int64_t block_start;
ssize_t block_length;
uint16_t width;
};
struct data_ready {
char used;
const uint8_t* buf;
size_t size;
int64_t offset;
};
struct cdeque {
uint16_t beg_pos;
uint16_t end_pos;
uint16_t cap_mask;
uint16_t size;
size_t* arr;
};
struct decode_table {
uint32_t size;
int32_t decode_len[16];
uint32_t decode_pos[16];
uint32_t quick_bits;
uint8_t quick_len[1 << 10];
uint16_t quick_num[1 << 10];
uint16_t decode_num[306];
};
struct comp_state {
/* Flag used to specify if unpacker needs to reinitialize the
uncompression context. */
uint8_t initialized : 1;
/* Flag used when applying filters. */
uint8_t all_filters_applied : 1;
/* Flag used to skip file context reinitialization, used when unpacker
is skipping through different multivolume archives. */
uint8_t switch_multivolume : 1;
/* Flag used to specify if unpacker has processed the whole data block
or just a part of it. */
uint8_t block_parsing_finished : 1;
signed int notused : 4;
int flags; /* Uncompression flags. */
int method; /* Uncompression algorithm method. */
int version; /* Uncompression algorithm version. */
ssize_t window_size; /* Size of window_buf. */
uint8_t* window_buf; /* Circular buffer used during
decompression. */
uint8_t* filtered_buf; /* Buffer used when applying filters. */
const uint8_t* block_buf; /* Buffer used when merging blocks. */
size_t window_mask; /* Convenience field; window_size - 1. */
int64_t write_ptr; /* This amount of data has been unpacked
in the window buffer. */
int64_t last_write_ptr; /* This amount of data has been stored in
the output file. */
int64_t last_unstore_ptr; /* Counter of bytes extracted during
unstoring. This is separate from
last_write_ptr because of how SERVICE
base blocks are handled during skipping
in solid multiarchive archives. */
int64_t solid_offset; /* Additional offset inside the window
buffer, used in unpacking solid
archives. */
ssize_t cur_block_size; /* Size of current data block. */
int last_len; /* Flag used in lzss decompression. */
/* Decode tables used during lzss uncompression. */
#define HUFF_BC 20
struct decode_table bd; /* huffman bit lengths */
#define HUFF_NC 306
struct decode_table ld; /* literals */
#define HUFF_DC 64
struct decode_table dd; /* distances */
#define HUFF_LDC 16
struct decode_table ldd; /* lower bits of distances */
#define HUFF_RC 44
struct decode_table rd; /* repeating distances */
#define HUFF_TABLE_SIZE (HUFF_NC + HUFF_DC + HUFF_RC + HUFF_LDC)
/* Circular deque for storing filters. */
struct cdeque filters;
int64_t last_block_start; /* Used for sanity checking. */
ssize_t last_block_length; /* Used for sanity checking. */
/* Distance cache used during lzss uncompression. */
int dist_cache[4];
/* Data buffer stack. */
struct data_ready dready[2];
};
/* Bit reader state. */
struct bit_reader {
int8_t bit_addr; /* Current bit pointer inside current byte. */
int in_addr; /* Current byte pointer. */
};
/* RARv5 block header structure. Use bf_* functions to get values from
* block_flags_u8 field. I.e. bf_byte_count, etc. */
struct compressed_block_header {
/* block_flags_u8 contain fields encoded in little-endian bitfield:
*
* - table present flag (shr 7, and 1),
* - last block flag (shr 6, and 1),
* - byte_count (shr 3, and 7),
* - bit_size (shr 0, and 7).
*/
uint8_t block_flags_u8;
uint8_t block_cksum;
};
/* RARv5 main header structure. */
struct main_header {
/* Does the archive contain solid streams? */
uint8_t solid : 1;
/* If this a multi-file archive? */
uint8_t volume : 1;
uint8_t endarc : 1;
uint8_t notused : 5;
unsigned int vol_no;
};
struct generic_header {
uint8_t split_after : 1;
uint8_t split_before : 1;
uint8_t padding : 6;
int size;
int last_header_id;
};
struct multivolume {
unsigned int expected_vol_no;
uint8_t* push_buf;
};
/* Main context structure. */
struct rar5 {
int header_initialized;
/* Set to 1 if current file is positioned AFTER the magic value
* of the archive file. This is used in header reading functions. */
int skipped_magic;
/* Set to not zero if we're in skip mode (either by calling
* rar5_data_skip function or when skipping over solid streams).
* Set to 0 when in * extraction mode. This is used during checksum
* calculation functions. */
int skip_mode;
/* Set to not zero if we're in block merging mode (i.e. when switching
* to another file in multivolume archive, last block from 1st archive
* needs to be merged with 1st block from 2nd archive). This flag
* guards against recursive use of the merging function, which doesn't
* support recursive calls. */
int merge_mode;
/* An offset to QuickOpen list. This is not supported by this unpacker,
* because we're focusing on streaming interface. QuickOpen is designed
* to make things quicker for non-stream interfaces, so it's not our
* use case. */
uint64_t qlist_offset;
/* An offset to additional Recovery data. This is not supported by this
* unpacker. Recovery data are additional Reed-Solomon codes that could
* be used to calculate bytes that are missing in archive or are
* corrupted. */
uint64_t rr_offset;
/* Various context variables grouped to different structures. */
struct generic_header generic;
struct main_header main;
struct comp_state cstate;
struct file_header file;
struct bit_reader bits;
struct multivolume vol;
/* The header of currently processed RARv5 block. Used in main
* decompression logic loop. */
struct compressed_block_header last_block_hdr;
};
/* Forward function declarations. */
static void rar5_signature(char *buf);
static int verify_global_checksums(struct archive_read* a);
static int rar5_read_data_skip(struct archive_read *a);
static int push_data_ready(struct archive_read* a, struct rar5* rar,
const uint8_t* buf, size_t size, int64_t offset);
/* CDE_xxx = Circular Double Ended (Queue) return values. */
enum CDE_RETURN_VALUES {
CDE_OK, CDE_ALLOC, CDE_PARAM, CDE_OUT_OF_BOUNDS,
};
/* Clears the contents of this circular deque. */
static void cdeque_clear(struct cdeque* d) {
d->size = 0;
d->beg_pos = 0;
d->end_pos = 0;
}
/* Creates a new circular deque object. Capacity must be power of 2: 8, 16, 32,
* 64, 256, etc. When the user will add another item above current capacity,
* the circular deque will overwrite the oldest entry. */
static int cdeque_init(struct cdeque* d, int max_capacity_power_of_2) {
if(d == NULL || max_capacity_power_of_2 == 0)
return CDE_PARAM;
d->cap_mask = max_capacity_power_of_2 - 1;
d->arr = NULL;
if((max_capacity_power_of_2 & d->cap_mask) != 0)
return CDE_PARAM;
cdeque_clear(d);
d->arr = malloc(sizeof(void*) * max_capacity_power_of_2);
return d->arr ? CDE_OK : CDE_ALLOC;
}
/* Return the current size (not capacity) of circular deque `d`. */
static size_t cdeque_size(struct cdeque* d) {
return d->size;
}
/* Returns the first element of current circular deque. Note that this function
* doesn't perform any bounds checking. If you need bounds checking, use
* `cdeque_front()` function instead. */
static void cdeque_front_fast(struct cdeque* d, void** value) {
*value = (void*) d->arr[d->beg_pos];
}
/* Returns the first element of current circular deque. This function
* performs bounds checking. */
static int cdeque_front(struct cdeque* d, void** value) {
if(d->size > 0) {
cdeque_front_fast(d, value);
return CDE_OK;
} else
return CDE_OUT_OF_BOUNDS;
}
/* Pushes a new element into the end of this circular deque object. If current
* size will exceed capacity, the oldest element will be overwritten. */
static int cdeque_push_back(struct cdeque* d, void* item) {
if(d == NULL)
return CDE_PARAM;
if(d->size == d->cap_mask + 1)
return CDE_OUT_OF_BOUNDS;
d->arr[d->end_pos] = (size_t) item;
d->end_pos = (d->end_pos + 1) & d->cap_mask;
d->size++;
return CDE_OK;
}
/* Pops a front element of this circular deque object and returns its value.
* This function doesn't perform any bounds checking. */
static void cdeque_pop_front_fast(struct cdeque* d, void** value) {
*value = (void*) d->arr[d->beg_pos];
d->beg_pos = (d->beg_pos + 1) & d->cap_mask;
d->size--;
}
/* Pops a front element of this circular deque object and returns its value.
* This function performs bounds checking. */
static int cdeque_pop_front(struct cdeque* d, void** value) {
if(!d || !value)
return CDE_PARAM;
if(d->size == 0)
return CDE_OUT_OF_BOUNDS;
cdeque_pop_front_fast(d, value);
return CDE_OK;
}
/* Convenience function to cast filter_info** to void **. */
static void** cdeque_filter_p(struct filter_info** f) {
return (void**) (size_t) f;
}
/* Convenience function to cast filter_info* to void *. */
static void* cdeque_filter(struct filter_info* f) {
return (void**) (size_t) f;
}
/* Destroys this circular deque object. Deallocates the memory of the
* collection buffer, but doesn't deallocate the memory of any pointer passed
* to this deque as a value. */
static void cdeque_free(struct cdeque* d) {
if(!d)
return;
if(!d->arr)
return;
free(d->arr);
d->arr = NULL;
d->beg_pos = -1;
d->end_pos = -1;
d->cap_mask = 0;
}
static inline
uint8_t bf_bit_size(const struct compressed_block_header* hdr) {
return hdr->block_flags_u8 & 7;
}
static inline
uint8_t bf_byte_count(const struct compressed_block_header* hdr) {
return (hdr->block_flags_u8 >> 3) & 7;
}
static inline
uint8_t bf_is_table_present(const struct compressed_block_header* hdr) {
return (hdr->block_flags_u8 >> 7) & 1;
}
static inline struct rar5* get_context(struct archive_read* a) {
return (struct rar5*) a->format->data;
}
/* Convenience functions used by filter implementations. */
static void circular_memcpy(uint8_t* dst, uint8_t* window, const uint64_t mask,
int64_t start, int64_t end)
{
if((start & mask) > (end & mask)) {
ssize_t len1 = mask + 1 - (start & mask);
ssize_t len2 = end & mask;
memcpy(dst, &window[start & mask], len1);
memcpy(dst + len1, window, len2);
} else {
memcpy(dst, &window[start & mask], (size_t) (end - start));
}
}
static uint32_t read_filter_data(struct rar5* rar, uint32_t offset) {
uint8_t linear_buf[4];
circular_memcpy(linear_buf, rar->cstate.window_buf,
rar->cstate.window_mask, offset, offset + 4);
return archive_le32dec(linear_buf);
}
static void write_filter_data(struct rar5* rar, uint32_t offset,
uint32_t value)
{
archive_le32enc(&rar->cstate.filtered_buf[offset], value);
}
/* Allocates a new filter descriptor and adds it to the filter array. */
static struct filter_info* add_new_filter(struct rar5* rar) {
struct filter_info* f =
(struct filter_info*) calloc(1, sizeof(struct filter_info));
if(!f) {
return NULL;
}
cdeque_push_back(&rar->cstate.filters, cdeque_filter(f));
return f;
}
static int run_delta_filter(struct rar5* rar, struct filter_info* flt) {
int i;
ssize_t dest_pos, src_pos = 0;
for(i = 0; i < flt->channels; i++) {
uint8_t prev_byte = 0;
for(dest_pos = i;
dest_pos < flt->block_length;
dest_pos += flt->channels)
{
uint8_t byte;
byte = rar->cstate.window_buf[
(rar->cstate.solid_offset + flt->block_start +
src_pos) & rar->cstate.window_mask];
prev_byte -= byte;
rar->cstate.filtered_buf[dest_pos] = prev_byte;
src_pos++;
}
}
return ARCHIVE_OK;
}
static int run_e8e9_filter(struct rar5* rar, struct filter_info* flt,
int extended)
{
const uint32_t file_size = 0x1000000;
ssize_t i;
circular_memcpy(rar->cstate.filtered_buf,
rar->cstate.window_buf, rar->cstate.window_mask,
rar->cstate.solid_offset + flt->block_start,
rar->cstate.solid_offset + flt->block_start + flt->block_length);
for(i = 0; i < flt->block_length - 4;) {
uint8_t b = rar->cstate.window_buf[
(rar->cstate.solid_offset + flt->block_start +
i++) & rar->cstate.window_mask];
/*
* 0xE8 = x86's call <relative_addr_uint32> (function call)
* 0xE9 = x86's jmp <relative_addr_uint32> (unconditional jump)
*/
if(b == 0xE8 || (extended && b == 0xE9)) {
uint32_t addr;
uint32_t offset = (i + flt->block_start) % file_size;
addr = read_filter_data(rar,
(uint32_t)(rar->cstate.solid_offset +
flt->block_start + i) & rar->cstate.window_mask);
if(addr & 0x80000000) {
if(((addr + offset) & 0x80000000) == 0) {
write_filter_data(rar, (uint32_t)i,
addr + file_size);
}
} else {
if((addr - file_size) & 0x80000000) {
uint32_t naddr = addr - offset;
write_filter_data(rar, (uint32_t)i,
naddr);
}
}
i += 4;
}
}
return ARCHIVE_OK;
}
static int run_arm_filter(struct rar5* rar, struct filter_info* flt) {
ssize_t i = 0;
uint32_t offset;
circular_memcpy(rar->cstate.filtered_buf,
rar->cstate.window_buf, rar->cstate.window_mask,
rar->cstate.solid_offset + flt->block_start,
rar->cstate.solid_offset + flt->block_start + flt->block_length);
for(i = 0; i < flt->block_length - 3; i += 4) {
uint8_t* b = &rar->cstate.window_buf[
(rar->cstate.solid_offset +
flt->block_start + i + 3) & rar->cstate.window_mask];
if(*b == 0xEB) {
/* 0xEB = ARM's BL (branch + link) instruction. */
offset = read_filter_data(rar,
(rar->cstate.solid_offset + flt->block_start + i) &
rar->cstate.window_mask) & 0x00ffffff;
offset -= (uint32_t) ((i + flt->block_start) / 4);
offset = (offset & 0x00ffffff) | 0xeb000000;
write_filter_data(rar, (uint32_t)i, offset);
}
}
return ARCHIVE_OK;
}
static int run_filter(struct archive_read* a, struct filter_info* flt) {
int ret;
struct rar5* rar = get_context(a);
free(rar->cstate.filtered_buf);
rar->cstate.filtered_buf = malloc(flt->block_length);
if(!rar->cstate.filtered_buf) {
archive_set_error(&a->archive, ENOMEM,
"Can't allocate memory for filter data.");
return ARCHIVE_FATAL;
}
switch(flt->type) {
case FILTER_DELTA:
ret = run_delta_filter(rar, flt);
break;
case FILTER_E8:
/* fallthrough */
case FILTER_E8E9:
ret = run_e8e9_filter(rar, flt,
flt->type == FILTER_E8E9);
break;
case FILTER_ARM:
ret = run_arm_filter(rar, flt);
break;
default:
archive_set_error(&a->archive,
ARCHIVE_ERRNO_FILE_FORMAT,
"Unsupported filter type: 0x%x", flt->type);
return ARCHIVE_FATAL;
}
if(ret != ARCHIVE_OK) {
/* Filter has failed. */
return ret;
}
if(ARCHIVE_OK != push_data_ready(a, rar, rar->cstate.filtered_buf,
flt->block_length, rar->cstate.last_write_ptr))
{
archive_set_error(&a->archive, ARCHIVE_ERRNO_PROGRAMMER,
"Stack overflow when submitting unpacked data");
return ARCHIVE_FATAL;
}
rar->cstate.last_write_ptr += flt->block_length;
return ARCHIVE_OK;
}
/* The `push_data` function submits the selected data range to the user.
* Next call of `use_data` will use the pointer, size and offset arguments
* that are specified here. These arguments are pushed to the FIFO stack here,
* and popped from the stack by the `use_data` function. */
static void push_data(struct archive_read* a, struct rar5* rar,
const uint8_t* buf, int64_t idx_begin, int64_t idx_end)
{
const uint64_t wmask = rar->cstate.window_mask;
const ssize_t solid_write_ptr = (rar->cstate.solid_offset +
rar->cstate.last_write_ptr) & wmask;
idx_begin += rar->cstate.solid_offset;
idx_end += rar->cstate.solid_offset;
/* Check if our unpacked data is wrapped inside the window circular
* buffer. If it's not wrapped, it can be copied out by using
* a single memcpy, but when it's wrapped, we need to copy the first
* part with one memcpy, and the second part with another memcpy. */
if((idx_begin & wmask) > (idx_end & wmask)) {
/* The data is wrapped (begin offset sis bigger than end
* offset). */
const ssize_t frag1_size = rar->cstate.window_size -
(idx_begin & wmask);
const ssize_t frag2_size = idx_end & wmask;
/* Copy the first part of the buffer first. */
push_data_ready(a, rar, buf + solid_write_ptr, frag1_size,
rar->cstate.last_write_ptr);
/* Copy the second part of the buffer. */
push_data_ready(a, rar, buf, frag2_size,
rar->cstate.last_write_ptr + frag1_size);
rar->cstate.last_write_ptr += frag1_size + frag2_size;
} else {
/* Data is not wrapped, so we can just use one call to copy the
* data. */
push_data_ready(a, rar,
buf + solid_write_ptr, (idx_end - idx_begin) & wmask,
rar->cstate.last_write_ptr);
rar->cstate.last_write_ptr += idx_end - idx_begin;
}
}
/* Convenience function that submits the data to the user. It uses the
* unpack window buffer as a source location. */
static void push_window_data(struct archive_read* a, struct rar5* rar,
int64_t idx_begin, int64_t idx_end)
{
push_data(a, rar, rar->cstate.window_buf, idx_begin, idx_end);
}
static int apply_filters(struct archive_read* a) {
struct filter_info* flt;
struct rar5* rar = get_context(a);
int ret;
rar->cstate.all_filters_applied = 0;
/* Get the first filter that can be applied to our data. The data
* needs to be fully unpacked before the filter can be run. */
if(CDE_OK == cdeque_front(&rar->cstate.filters,
cdeque_filter_p(&flt))) {
/* Check if our unpacked data fully covers this filter's
* range. */
if(rar->cstate.write_ptr > flt->block_start &&
rar->cstate.write_ptr >= flt->block_start +
flt->block_length) {
/* Check if we have some data pending to be written
* right before the filter's start offset. */
if(rar->cstate.last_write_ptr == flt->block_start) {
/* Run the filter specified by descriptor
* `flt`. */
ret = run_filter(a, flt);
if(ret != ARCHIVE_OK) {
/* Filter failure, return error. */
return ret;
}
/* Filter descriptor won't be needed anymore
* after it's used, * so remove it from the
* filter list and free its memory. */
(void) cdeque_pop_front(&rar->cstate.filters,
cdeque_filter_p(&flt));
free(flt);
} else {
/* We can't run filters yet, dump the memory
* right before the filter. */
push_window_data(a, rar,
rar->cstate.last_write_ptr,
flt->block_start);
}
/* Return 'filter applied or not needed' state to the
* caller. */
return ARCHIVE_RETRY;
}
}
rar->cstate.all_filters_applied = 1;
return ARCHIVE_OK;
}
static void dist_cache_push(struct rar5* rar, int value) {
int* q = rar->cstate.dist_cache;
q[3] = q[2];
q[2] = q[1];
q[1] = q[0];
q[0] = value;
}
static int dist_cache_touch(struct rar5* rar, int idx) {
int* q = rar->cstate.dist_cache;
int i, dist = q[idx];
for(i = idx; i > 0; i--)
q[i] = q[i - 1];
q[0] = dist;
return dist;
}
static void free_filters(struct rar5* rar) {
struct cdeque* d = &rar->cstate.filters;
/* Free any remaining filters. All filters should be naturally
* consumed by the unpacking function, so remaining filters after
* unpacking normally mean that unpacking wasn't successful.
* But still of course we shouldn't leak memory in such case. */
/* cdeque_size() is a fast operation, so we can use it as a loop
* expression. */
while(cdeque_size(d) > 0) {
struct filter_info* f = NULL;
/* Pop_front will also decrease the collection's size. */
if (CDE_OK == cdeque_pop_front(d, cdeque_filter_p(&f)))
free(f);
}
cdeque_clear(d);
/* Also clear out the variables needed for sanity checking. */
rar->cstate.last_block_start = 0;
rar->cstate.last_block_length = 0;
}
static void reset_file_context(struct rar5* rar) {
memset(&rar->file, 0, sizeof(rar->file));
blake2sp_init(&rar->file.b2state, 32);
if(rar->main.solid) {
rar->cstate.solid_offset += rar->cstate.write_ptr;
} else {
rar->cstate.solid_offset = 0;
}
rar->cstate.write_ptr = 0;
rar->cstate.last_write_ptr = 0;
rar->cstate.last_unstore_ptr = 0;
rar->file.redir_type = REDIR_TYPE_NONE;
rar->file.redir_flags = 0;
free_filters(rar);
}
static inline int get_archive_read(struct archive* a,
struct archive_read** ar)
{
*ar = (struct archive_read*) a;
archive_check_magic(a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_NEW,
"archive_read_support_format_rar5");
return ARCHIVE_OK;
}
static int read_ahead(struct archive_read* a, size_t how_many,
const uint8_t** ptr)
{
ssize_t avail = -1;
if(!ptr)
return 0;
*ptr = __archive_read_ahead(a, how_many, &avail);
if(*ptr == NULL) {
return 0;
}
return 1;
}
static int consume(struct archive_read* a, int64_t how_many) {
int ret;
ret = how_many == __archive_read_consume(a, how_many)
? ARCHIVE_OK
: ARCHIVE_FATAL;
return ret;
}
/**
* Read a RAR5 variable sized numeric value. This value will be stored in
* `pvalue`. The `pvalue_len` argument points to a variable that will receive
* the byte count that was consumed in order to decode the `pvalue` value, plus
* one.
*
* pvalue_len is optional and can be NULL.
*
* NOTE: if `pvalue_len` is NOT NULL, the caller needs to manually consume
* the number of bytes that `pvalue_len` value contains. If the `pvalue_len`
* is NULL, this consuming operation is done automatically.
*
* Returns 1 if *pvalue was successfully read.
* Returns 0 if there was an error. In this case, *pvalue contains an
* invalid value.
*/
static int read_var(struct archive_read* a, uint64_t* pvalue,
uint64_t* pvalue_len)
{
uint64_t result = 0;
size_t shift, i;
const uint8_t* p;
uint8_t b;
/* We will read maximum of 8 bytes. We don't have to handle the
* situation to read the RAR5 variable-sized value stored at the end of
* the file, because such situation will never happen. */
if(!read_ahead(a, 8, &p))
return 0;
for(shift = 0, i = 0; i < 8; i++, shift += 7) {
b = p[i];
/* Strip the MSB from the input byte and add the resulting
* number to the `result`. */
result += (b & (uint64_t)0x7F) << shift;
/* MSB set to 1 means we need to continue decoding process.
* MSB set to 0 means we're done.
*
* This conditional checks for the second case. */
if((b & 0x80) == 0) {
if(pvalue) {
*pvalue = result;
}
/* If the caller has passed the `pvalue_len` pointer,
* store the number of consumed bytes in it and do NOT
* consume those bytes, since the caller has all the
* information it needs to perform */
if(pvalue_len) {
*pvalue_len = 1 + i;
} else {
/* If the caller did not provide the
* `pvalue_len` pointer, it will not have the
* possibility to advance the file pointer,
* because it will not know how many bytes it
* needs to consume. This is why we handle
* such situation here automatically. */
if(ARCHIVE_OK != consume(a, 1 + i)) {
return 0;
}
}
/* End of decoding process, return success. */
return 1;
}
}
/* The decoded value takes the maximum number of 8 bytes.
* It's a maximum number of bytes, so end decoding process here
* even if the first bit of last byte is 1. */
if(pvalue) {
*pvalue = result;
}
if(pvalue_len) {
*pvalue_len = 9;
} else {
if(ARCHIVE_OK != consume(a, 9)) {
return 0;
}
}
return 1;
}
static int read_var_sized(struct archive_read* a, size_t* pvalue,
size_t* pvalue_len)
{
uint64_t v;
uint64_t v_size = 0;
const int ret = pvalue_len ? read_var(a, &v, &v_size)
: read_var(a, &v, NULL);
if(ret == 1 && pvalue) {
*pvalue = (size_t) v;
}
if(pvalue_len) {
/* Possible data truncation should be safe. */
*pvalue_len = (size_t) v_size;
}
return ret;
}
static int read_bits_32(struct archive_read* a, struct rar5* rar,
const uint8_t* p, uint32_t* value)
{
if(rar->bits.in_addr >= rar->cstate.cur_block_size) {
archive_set_error(&a->archive,
ARCHIVE_ERRNO_PROGRAMMER,
"Premature end of stream during extraction of data (#1)");
return ARCHIVE_FATAL;
}
uint32_t bits = ((uint32_t) p[rar->bits.in_addr]) << 24;
bits |= p[rar->bits.in_addr + 1] << 16;
bits |= p[rar->bits.in_addr + 2] << 8;
bits |= p[rar->bits.in_addr + 3];
bits <<= rar->bits.bit_addr;
bits |= p[rar->bits.in_addr + 4] >> (8 - rar->bits.bit_addr);
*value = bits;
return ARCHIVE_OK;
}
static int read_bits_16(struct archive_read* a, struct rar5* rar,
const uint8_t* p, uint16_t* value)
{
if(rar->bits.in_addr >= rar->cstate.cur_block_size) {
archive_set_error(&a->archive,
ARCHIVE_ERRNO_PROGRAMMER,
"Premature end of stream during extraction of data (#2)");
return ARCHIVE_FATAL;
}
int bits = (int) ((uint32_t) p[rar->bits.in_addr]) << 16;
bits |= (int) p[rar->bits.in_addr + 1] << 8;
bits |= (int) p[rar->bits.in_addr + 2];
bits >>= (8 - rar->bits.bit_addr);
*value = bits & 0xffff;
return ARCHIVE_OK;
}
static void skip_bits(struct rar5* rar, int bits) {
const int new_bits = rar->bits.bit_addr + bits;
rar->bits.in_addr += new_bits >> 3;
rar->bits.bit_addr = new_bits & 7;
}
/* n = up to 16 */
static int read_consume_bits(struct archive_read* a, struct rar5* rar,
const uint8_t* p, int n, int* value)
{
uint16_t v;
int ret, num;
if(n == 0 || n > 16) {
/* This is a programmer error and should never happen
* in runtime. */
return ARCHIVE_FATAL;
}
ret = read_bits_16(a, rar, p, &v);
if(ret != ARCHIVE_OK)
return ret;
num = (int) v;
num >>= 16 - n;
skip_bits(rar, n);
if(value)
*value = num;
return ARCHIVE_OK;
}
static int read_u32(struct archive_read* a, uint32_t* pvalue) {
const uint8_t* p;
if(!read_ahead(a, 4, &p))
return 0;
*pvalue = archive_le32dec(p);
return ARCHIVE_OK == consume(a, 4) ? 1 : 0;
}
static int read_u64(struct archive_read* a, uint64_t* pvalue) {
const uint8_t* p;
if(!read_ahead(a, 8, &p))
return 0;
*pvalue = archive_le64dec(p);
return ARCHIVE_OK == consume(a, 8) ? 1 : 0;
}
static int bid_standard(struct archive_read* a) {
const uint8_t* p;
char signature[sizeof(rar5_signature_xor)];
rar5_signature(signature);
if(!read_ahead(a, sizeof(rar5_signature_xor), &p))
return -1;
if(!memcmp(signature, p, sizeof(rar5_signature_xor)))
return 30;
return -1;
}
static int rar5_bid(struct archive_read* a, int best_bid) {
int my_bid;
if(best_bid > 30)
return -1;
my_bid = bid_standard(a);
if(my_bid > -1) {
return my_bid;
}
return -1;
}
static int rar5_options(struct archive_read *a, const char *key,
const char *val) {
(void) a;
(void) key;
(void) val;
/* No options supported in this version. Return the ARCHIVE_WARN code
* to signal the options supervisor that the unpacker didn't handle
* setting this option. */
return ARCHIVE_WARN;
}
static void init_header(struct archive_read* a) {
a->archive.archive_format = ARCHIVE_FORMAT_RAR_V5;
a->archive.archive_format_name = "RAR5";
}
static void init_window_mask(struct rar5* rar) {
if (rar->cstate.window_size)
rar->cstate.window_mask = rar->cstate.window_size - 1;
else
rar->cstate.window_mask = 0;
}
enum HEADER_FLAGS {
HFL_EXTRA_DATA = 0x0001,
HFL_DATA = 0x0002,
HFL_SKIP_IF_UNKNOWN = 0x0004,
HFL_SPLIT_BEFORE = 0x0008,
HFL_SPLIT_AFTER = 0x0010,
HFL_CHILD = 0x0020,
HFL_INHERITED = 0x0040
};
static int process_main_locator_extra_block(struct archive_read* a,
struct rar5* rar)
{
uint64_t locator_flags;
enum LOCATOR_FLAGS {
QLIST = 0x01, RECOVERY = 0x02,
};
if(!read_var(a, &locator_flags, NULL)) {
return ARCHIVE_EOF;
}
if(locator_flags & QLIST) {
if(!read_var(a, &rar->qlist_offset, NULL)) {
return ARCHIVE_EOF;
}
/* qlist is not used */
}
if(locator_flags & RECOVERY) {
if(!read_var(a, &rar->rr_offset, NULL)) {
return ARCHIVE_EOF;
}
/* rr is not used */
}
return ARCHIVE_OK;
}
static int parse_file_extra_hash(struct archive_read* a, struct rar5* rar,
ssize_t* extra_data_size)
{
size_t hash_type = 0;
size_t value_len;
enum HASH_TYPE {
BLAKE2sp = 0x00
};
if(!read_var_sized(a, &hash_type, &value_len))
return ARCHIVE_EOF;
*extra_data_size -= value_len;
if(ARCHIVE_OK != consume(a, value_len)) {
return ARCHIVE_EOF;
}
/* The file uses BLAKE2sp checksum algorithm instead of plain old
* CRC32. */
if(hash_type == BLAKE2sp) {
const uint8_t* p;
const int hash_size = sizeof(rar->file.blake2sp);
if(!read_ahead(a, hash_size, &p))
return ARCHIVE_EOF;
rar->file.has_blake2 = 1;
memcpy(&rar->file.blake2sp, p, hash_size);
if(ARCHIVE_OK != consume(a, hash_size)) {
return ARCHIVE_EOF;
}
*extra_data_size -= hash_size;
} else {
archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
"Unsupported hash type (0x%x)", (int) hash_type);
return ARCHIVE_FATAL;
}
return ARCHIVE_OK;
}
static uint64_t time_win_to_unix(uint64_t win_time) {
const size_t ns_in_sec = 10000000;
const uint64_t sec_to_unix = 11644473600LL;
return win_time / ns_in_sec - sec_to_unix;
}
static int parse_htime_item(struct archive_read* a, char unix_time,
uint64_t* where, ssize_t* extra_data_size)
{
if(unix_time) {
uint32_t time_val;
if(!read_u32(a, &time_val))
return ARCHIVE_EOF;
*extra_data_size -= 4;
*where = (uint64_t) time_val;
} else {
uint64_t windows_time;
if(!read_u64(a, &windows_time))
return ARCHIVE_EOF;
*where = time_win_to_unix(windows_time);
*extra_data_size -= 8;
}
return ARCHIVE_OK;
}
static int parse_file_extra_version(struct archive_read* a,
struct archive_entry* e, ssize_t* extra_data_size)
{
size_t flags = 0;
size_t version = 0;
size_t value_len = 0;
struct archive_string version_string;
struct archive_string name_utf8_string;
const char* cur_filename;
/* Flags are ignored. */
if(!read_var_sized(a, &flags, &value_len))
return ARCHIVE_EOF;
*extra_data_size -= value_len;
if(ARCHIVE_OK != consume(a, value_len))
return ARCHIVE_EOF;
if(!read_var_sized(a, &version, &value_len))
return ARCHIVE_EOF;
*extra_data_size -= value_len;
if(ARCHIVE_OK != consume(a, value_len))
return ARCHIVE_EOF;
/* extra_data_size should be zero here. */
cur_filename = archive_entry_pathname_utf8(e);
if(cur_filename == NULL) {
archive_set_error(&a->archive, ARCHIVE_ERRNO_PROGRAMMER,
"Version entry without file name");
return ARCHIVE_FATAL;
}
archive_string_init(&version_string);
archive_string_init(&name_utf8_string);
/* Prepare a ;123 suffix for the filename, where '123' is the version
* value of this file. */
archive_string_sprintf(&version_string, ";%zu", version);
/* Build the new filename. */
archive_strcat(&name_utf8_string, cur_filename);
archive_strcat(&name_utf8_string, version_string.s);
/* Apply the new filename into this file's context. */
archive_entry_update_pathname_utf8(e, name_utf8_string.s);
/* Free buffers. */
archive_string_free(&version_string);
archive_string_free(&name_utf8_string);
return ARCHIVE_OK;
}
static int parse_file_extra_htime(struct archive_read* a,
struct archive_entry* e, struct rar5* rar, ssize_t* extra_data_size)
{
char unix_time = 0;
size_t flags = 0;
size_t value_len;
enum HTIME_FLAGS {
IS_UNIX = 0x01,
HAS_MTIME = 0x02,
HAS_CTIME = 0x04,
HAS_ATIME = 0x08,
HAS_UNIX_NS = 0x10,
};
if(!read_var_sized(a, &flags, &value_len))
return ARCHIVE_EOF;
*extra_data_size -= value_len;
if(ARCHIVE_OK != consume(a, value_len)) {
return ARCHIVE_EOF;
}
unix_time = flags & IS_UNIX;
if(flags & HAS_MTIME) {
parse_htime_item(a, unix_time, &rar->file.e_mtime,
extra_data_size);
archive_entry_set_mtime(e, rar->file.e_mtime, 0);
}
if(flags & HAS_CTIME) {
parse_htime_item(a, unix_time, &rar->file.e_ctime,
extra_data_size);
archive_entry_set_ctime(e, rar->file.e_ctime, 0);
}
if(flags & HAS_ATIME) {
parse_htime_item(a, unix_time, &rar->file.e_atime,
extra_data_size);
archive_entry_set_atime(e, rar->file.e_atime, 0);
}
if(flags & HAS_UNIX_NS) {
if(!read_u32(a, &rar->file.e_unix_ns))
return ARCHIVE_EOF;
*extra_data_size -= 4;
}
return ARCHIVE_OK;
}
static int parse_file_extra_redir(struct archive_read* a,
struct archive_entry* e, struct rar5* rar, ssize_t* extra_data_size)
{
uint64_t value_size = 0;
size_t target_size = 0;
char target_utf8_buf[MAX_NAME_IN_BYTES];
const uint8_t* p;
if(!read_var(a, &rar->file.redir_type, &value_size))
return ARCHIVE_EOF;
if(ARCHIVE_OK != consume(a, (int64_t)value_size))
return ARCHIVE_EOF;
*extra_data_size -= value_size;
if(!read_var(a, &rar->file.redir_flags, &value_size))
return ARCHIVE_EOF;
if(ARCHIVE_OK != consume(a, (int64_t)value_size))
return ARCHIVE_EOF;
*extra_data_size -= value_size;
if(!read_var_sized(a, &target_size, NULL))
return ARCHIVE_EOF;
*extra_data_size -= target_size + 1;
if(!read_ahead(a, target_size, &p))
return ARCHIVE_EOF;
if(target_size > (MAX_NAME_IN_CHARS - 1)) {
archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
"Link target is too long");
return ARCHIVE_FATAL;
}
if(target_size == 0) {
archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
"No link target specified");
return ARCHIVE_FATAL;
}
memcpy(target_utf8_buf, p, target_size);
target_utf8_buf[target_size] = 0;
if(ARCHIVE_OK != consume(a, (int64_t)target_size))
return ARCHIVE_EOF;
switch(rar->file.redir_type) {
case REDIR_TYPE_UNIXSYMLINK:
case REDIR_TYPE_WINSYMLINK:
archive_entry_set_filetype(e, AE_IFLNK);
archive_entry_update_symlink_utf8(e, target_utf8_buf);
if (rar->file.redir_flags & REDIR_SYMLINK_IS_DIR) {
archive_entry_set_symlink_type(e,
AE_SYMLINK_TYPE_DIRECTORY);
} else {
archive_entry_set_symlink_type(e,
AE_SYMLINK_TYPE_FILE);
}
break;
case REDIR_TYPE_HARDLINK:
archive_entry_set_filetype(e, AE_IFREG);
archive_entry_update_hardlink_utf8(e, target_utf8_buf);
break;
default:
/* Unknown redir type, skip it. */
break;
}
return ARCHIVE_OK;
}
static int parse_file_extra_owner(struct archive_read* a,
struct archive_entry* e, ssize_t* extra_data_size)
{
uint64_t flags = 0;
uint64_t value_size = 0;
uint64_t id = 0;
size_t name_len = 0;
size_t name_size = 0;
char namebuf[OWNER_MAXNAMELEN];
const uint8_t* p;
if(!read_var(a, &flags, &value_size))
return ARCHIVE_EOF;
if(ARCHIVE_OK != consume(a, (int64_t)value_size))
return ARCHIVE_EOF;
*extra_data_size -= value_size;
if ((flags & OWNER_USER_NAME) != 0) {
if(!read_var_sized(a, &name_size, NULL))
return ARCHIVE_EOF;
*extra_data_size -= name_size + 1;
if(!read_ahead(a, name_size, &p))
return ARCHIVE_EOF;
if (name_size >= OWNER_MAXNAMELEN) {
name_len = OWNER_MAXNAMELEN - 1;
} else {
name_len = name_size;
}
memcpy(namebuf, p, name_len);
namebuf[name_len] = 0;
if(ARCHIVE_OK != consume(a, (int64_t)name_size))
return ARCHIVE_EOF;
archive_entry_set_uname(e, namebuf);
}
if ((flags & OWNER_GROUP_NAME) != 0) {
if(!read_var_sized(a, &name_size, NULL))
return ARCHIVE_EOF;
*extra_data_size -= name_size + 1;
if(!read_ahead(a, name_size, &p))
return ARCHIVE_EOF;
if (name_size >= OWNER_MAXNAMELEN) {
name_len = OWNER_MAXNAMELEN - 1;
} else {
name_len = name_size;
}
memcpy(namebuf, p, name_len);
namebuf[name_len] = 0;
if(ARCHIVE_OK != consume(a, (int64_t)name_size))
return ARCHIVE_EOF;
archive_entry_set_gname(e, namebuf);
}
if ((flags & OWNER_USER_UID) != 0) {
if(!read_var(a, &id, &value_size))
return ARCHIVE_EOF;
if(ARCHIVE_OK != consume(a, (int64_t)value_size))
return ARCHIVE_EOF;
*extra_data_size -= value_size;
archive_entry_set_uid(e, (la_int64_t)id);
}
if ((flags & OWNER_GROUP_GID) != 0) {
if(!read_var(a, &id, &value_size))
return ARCHIVE_EOF;
if(ARCHIVE_OK != consume(a, (int64_t)value_size))
return ARCHIVE_EOF;
*extra_data_size -= value_size;
archive_entry_set_gid(e, (la_int64_t)id);
}
return ARCHIVE_OK;
}
static int process_head_file_extra(struct archive_read* a,
struct archive_entry* e, struct rar5* rar, ssize_t extra_data_size)
{
size_t extra_field_size;
size_t extra_field_id = 0;
int ret = ARCHIVE_FATAL;
size_t var_size;
while(extra_data_size > 0) {
if(!read_var_sized(a, &extra_field_size, &var_size))
return ARCHIVE_EOF;
extra_data_size -= var_size;
if(ARCHIVE_OK != consume(a, var_size)) {
return ARCHIVE_EOF;
}
if(!read_var_sized(a, &extra_field_id, &var_size))
return ARCHIVE_EOF;
extra_data_size -= var_size;
if(ARCHIVE_OK != consume(a, var_size)) {
return ARCHIVE_EOF;
}
switch(extra_field_id) {
case EX_HASH:
ret = parse_file_extra_hash(a, rar,
&extra_data_size);
break;
case EX_HTIME:
ret = parse_file_extra_htime(a, e, rar,
&extra_data_size);
break;
case EX_REDIR:
ret = parse_file_extra_redir(a, e, rar,
&extra_data_size);
break;
case EX_UOWNER:
ret = parse_file_extra_owner(a, e,
&extra_data_size);
break;
case EX_VERSION:
ret = parse_file_extra_version(a, e,
&extra_data_size);
break;
case EX_CRYPT:
/* fallthrough */
case EX_SUBDATA:
/* fallthrough */
default:
/* Skip unsupported entry. */
return consume(a, extra_data_size);
}
}
if(ret != ARCHIVE_OK) {
/* Attribute not implemented. */
return ret;
}
return ARCHIVE_OK;
}
static int process_head_file(struct archive_read* a, struct rar5* rar,
struct archive_entry* entry, size_t block_flags)
{
ssize_t extra_data_size = 0;
size_t data_size = 0;
size_t file_flags = 0;
size_t file_attr = 0;
size_t compression_info = 0;
size_t host_os = 0;
size_t name_size = 0;
uint64_t unpacked_size, window_size;
uint32_t mtime = 0, crc = 0;
int c_method = 0, c_version = 0;
char name_utf8_buf[MAX_NAME_IN_BYTES];
const uint8_t* p;
enum FILE_FLAGS {
DIRECTORY = 0x0001, UTIME = 0x0002, CRC32 = 0x0004,
UNKNOWN_UNPACKED_SIZE = 0x0008,
};
enum FILE_ATTRS {
ATTR_READONLY = 0x1, ATTR_HIDDEN = 0x2, ATTR_SYSTEM = 0x4,
ATTR_DIRECTORY = 0x10,
};
enum COMP_INFO_FLAGS {
SOLID = 0x0040,
};
enum HOST_OS {
HOST_WINDOWS = 0,
HOST_UNIX = 1,
};
archive_entry_clear(entry);
/* Do not reset file context if we're switching archives. */
if(!rar->cstate.switch_multivolume) {
reset_file_context(rar);
}
if(block_flags & HFL_EXTRA_DATA) {
size_t edata_size = 0;
if(!read_var_sized(a, &edata_size, NULL))
return ARCHIVE_EOF;
/* Intentional type cast from unsigned to signed. */
extra_data_size = (ssize_t) edata_size;
}
if(block_flags & HFL_DATA) {
if(!read_var_sized(a, &data_size, NULL))
return ARCHIVE_EOF;
rar->file.bytes_remaining = data_size;
} else {
rar->file.bytes_remaining = 0;
archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
"no data found in file/service block");
return ARCHIVE_FATAL;
}
if(!read_var_sized(a, &file_flags, NULL))
return ARCHIVE_EOF;
if(!read_var(a, &unpacked_size, NULL))
return ARCHIVE_EOF;
if(file_flags & UNKNOWN_UNPACKED_SIZE) {
archive_set_error(&a->archive, ARCHIVE_ERRNO_PROGRAMMER,
"Files with unknown unpacked size are not supported");
return ARCHIVE_FATAL;
}
rar->file.dir = (uint8_t) ((file_flags & DIRECTORY) > 0);
if(!read_var_sized(a, &file_attr, NULL))
return ARCHIVE_EOF;
if(file_flags & UTIME) {
if(!read_u32(a, &mtime))
return ARCHIVE_EOF;
}
if(file_flags & CRC32) {
if(!read_u32(a, &crc))
return ARCHIVE_EOF;
}
if(!read_var_sized(a, &compression_info, NULL))
return ARCHIVE_EOF;
c_method = (int) (compression_info >> 7) & 0x7;
c_version = (int) (compression_info & 0x3f);
/* RAR5 seems to limit the dictionary size to 64MB. */
window_size = (rar->file.dir > 0) ?
0 :
g_unpack_window_size << ((compression_info >> 10) & 15);
rar->cstate.method = c_method;
rar->cstate.version = c_version + 50;
rar->file.solid = (compression_info & SOLID) > 0;
/* Archives which declare solid files without initializing the window
* buffer first are invalid. */
if(rar->file.solid > 0 && rar->cstate.window_buf == NULL) {
archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
"Declared solid file, but no window buffer "
"initialized yet.");
return ARCHIVE_FATAL;
}
/* Check if window_size is a sane value. Also, if the file is not
* declared as a directory, disallow window_size == 0. */
if(window_size > (64 * 1024 * 1024) ||
(rar->file.dir == 0 && window_size == 0))
{
archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
"Declared dictionary size is not supported.");
return ARCHIVE_FATAL;
}
if(rar->file.solid > 0) {
/* Re-check if current window size is the same as previous
* window size (for solid files only). */
if(rar->file.solid_window_size > 0 &&
rar->file.solid_window_size != (ssize_t) window_size)
{
archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
"Window size for this solid file doesn't match "
"the window size used in previous solid file. ");
return ARCHIVE_FATAL;
}
}
if(rar->cstate.window_size < (ssize_t) window_size &&
rar->cstate.window_buf)
{
/* If window_buf has been allocated before, reallocate it, so
* that its size will match new window_size. */
uint8_t* new_window_buf =
realloc(rar->cstate.window_buf, window_size);
if(!new_window_buf) {
archive_set_error(&a->archive, ARCHIVE_ERRNO_PROGRAMMER,
"Not enough memory when trying to realloc the window "
"buffer.");
return ARCHIVE_FATAL;
}
rar->cstate.window_buf = new_window_buf;
}
/* Values up to 64M should fit into ssize_t on every
* architecture. */
rar->cstate.window_size = (ssize_t) window_size;
if(rar->file.solid > 0 && rar->file.solid_window_size == 0) {
/* Solid files have to have the same window_size across
whole archive. Remember the window_size parameter
for first solid file found. */
rar->file.solid_window_size = rar->cstate.window_size;
}
init_window_mask(rar);
rar->file.service = 0;
if(!read_var_sized(a, &host_os, NULL))
return ARCHIVE_EOF;
if(host_os == HOST_WINDOWS) {
/* Host OS is Windows */
__LA_MODE_T mode;
if(file_attr & ATTR_DIRECTORY) {
if (file_attr & ATTR_READONLY) {
mode = 0555 | AE_IFDIR;
} else {
mode = 0755 | AE_IFDIR;
}
} else {
if (file_attr & ATTR_READONLY) {
mode = 0444 | AE_IFREG;
} else {
mode = 0644 | AE_IFREG;
}
}
archive_entry_set_mode(entry, mode);
if (file_attr & (ATTR_READONLY | ATTR_HIDDEN | ATTR_SYSTEM)) {
char *fflags_text, *ptr;
/* allocate for "rdonly,hidden,system," */
fflags_text = malloc(22 * sizeof(char));
if (fflags_text != NULL) {
ptr = fflags_text;
if (file_attr & ATTR_READONLY) {
strcpy(ptr, "rdonly,");
ptr = ptr + 7;
}
if (file_attr & ATTR_HIDDEN) {
strcpy(ptr, "hidden,");
ptr = ptr + 7;
}
if (file_attr & ATTR_SYSTEM) {
strcpy(ptr, "system,");
ptr = ptr + 7;
}
if (ptr > fflags_text) {
/* Delete trailing comma */
*(ptr - 1) = '\0';
archive_entry_copy_fflags_text(entry,
fflags_text);
}
free(fflags_text);
}
}
} else if(host_os == HOST_UNIX) {
/* Host OS is Unix */
archive_entry_set_mode(entry, (__LA_MODE_T) file_attr);
} else {
/* Unknown host OS */
archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
"Unsupported Host OS: 0x%x", (int) host_os);
return ARCHIVE_FATAL;
}
if(!read_var_sized(a, &name_size, NULL))
return ARCHIVE_EOF;
if(!read_ahead(a, name_size, &p))
return ARCHIVE_EOF;
if(name_size > (MAX_NAME_IN_CHARS - 1)) {
archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
"Filename is too long");
return ARCHIVE_FATAL;
}
if(name_size == 0) {
archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
"No filename specified");
return ARCHIVE_FATAL;
}
memcpy(name_utf8_buf, p, name_size);
name_utf8_buf[name_size] = 0;
if(ARCHIVE_OK != consume(a, name_size)) {
return ARCHIVE_EOF;
}
archive_entry_update_pathname_utf8(entry, name_utf8_buf);
if(extra_data_size > 0) {
int ret = process_head_file_extra(a, entry, rar,
extra_data_size);
/*
* TODO: rewrite or remove useless sanity check
* as extra_data_size is not passed as a pointer
*
if(extra_data_size < 0) {
archive_set_error(&a->archive, ARCHIVE_ERRNO_PROGRAMMER,
"File extra data size is not zero");
return ARCHIVE_FATAL;
}
*/
if(ret != ARCHIVE_OK)
return ret;
}
if((file_flags & UNKNOWN_UNPACKED_SIZE) == 0) {
rar->file.unpacked_size = (ssize_t) unpacked_size;
if(rar->file.redir_type == REDIR_TYPE_NONE)
archive_entry_set_size(entry, unpacked_size);
}
if(file_flags & UTIME) {
archive_entry_set_mtime(entry, (time_t) mtime, 0);
}
if(file_flags & CRC32) {
rar->file.stored_crc32 = crc;
}
if(!rar->cstate.switch_multivolume) {
/* Do not reinitialize unpacking state if we're switching
* archives. */
rar->cstate.block_parsing_finished = 1;
rar->cstate.all_filters_applied = 1;
rar->cstate.initialized = 0;
}
if(rar->generic.split_before > 0) {
/* If now we're standing on a header that has a 'split before'
* mark, it means we're standing on a 'continuation' file
* header. Signal the caller that if it wants to move to
* another file, it must call rar5_read_header() function
* again. */
return ARCHIVE_RETRY;
} else {
return ARCHIVE_OK;
}
}
static int process_head_service(struct archive_read* a, struct rar5* rar,
struct archive_entry* entry, size_t block_flags)
{
/* Process this SERVICE block the same way as FILE blocks. */
int ret = process_head_file(a, rar, entry, block_flags);
if(ret != ARCHIVE_OK)
return ret;
rar->file.service = 1;
/* But skip the data part automatically. It's no use for the user
* anyway. It contains only service data, not even needed to
* properly unpack the file. */
ret = rar5_read_data_skip(a);
if(ret != ARCHIVE_OK)
return ret;
/* After skipping, try parsing another block automatically. */
return ARCHIVE_RETRY;
}
static int process_head_main(struct archive_read* a, struct rar5* rar,
struct archive_entry* entry, size_t block_flags)
{
int ret;
size_t extra_data_size = 0;
size_t extra_field_size = 0;
size_t extra_field_id = 0;
size_t archive_flags = 0;
enum MAIN_FLAGS {
VOLUME = 0x0001, /* multi-volume archive */
VOLUME_NUMBER = 0x0002, /* volume number, first vol doesn't
* have it */
SOLID = 0x0004, /* solid archive */
PROTECT = 0x0008, /* contains Recovery info */
LOCK = 0x0010, /* readonly flag, not used */
};
enum MAIN_EXTRA {
// Just one attribute here.
LOCATOR = 0x01,
};
(void) entry;
if(block_flags & HFL_EXTRA_DATA) {
if(!read_var_sized(a, &extra_data_size, NULL))
return ARCHIVE_EOF;
} else {
extra_data_size = 0;
}
if(!read_var_sized(a, &archive_flags, NULL)) {
return ARCHIVE_EOF;
}
rar->main.volume = (archive_flags & VOLUME) > 0;
rar->main.solid = (archive_flags & SOLID) > 0;
if(archive_flags & VOLUME_NUMBER) {
size_t v = 0;
if(!read_var_sized(a, &v, NULL)) {
return ARCHIVE_EOF;
}
if (v > UINT_MAX) {
archive_set_error(&a->archive,
ARCHIVE_ERRNO_FILE_FORMAT,
"Invalid volume number");
return ARCHIVE_FATAL;
}
rar->main.vol_no = (unsigned int) v;
} else {
rar->main.vol_no = 0;
}
if(rar->vol.expected_vol_no > 0 &&
rar->main.vol_no != rar->vol.expected_vol_no)
{
/* Returning EOF instead of FATAL because of strange
* libarchive behavior. When opening multiple files via
* archive_read_open_filenames(), after reading up the whole
* last file, the __archive_read_ahead function wraps up to
* the first archive instead of returning EOF. */
return ARCHIVE_EOF;
}
if(extra_data_size == 0) {
/* Early return. */
return ARCHIVE_OK;
}
if(!read_var_sized(a, &extra_field_size, NULL)) {
return ARCHIVE_EOF;
}
if(!read_var_sized(a, &extra_field_id, NULL)) {
return ARCHIVE_EOF;
}
if(extra_field_size == 0) {
archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
"Invalid extra field size");
return ARCHIVE_FATAL;
}
switch(extra_field_id) {
case LOCATOR:
ret = process_main_locator_extra_block(a, rar);
if(ret != ARCHIVE_OK) {
/* Error while parsing main locator extra
* block. */
return ret;
}
break;
default:
archive_set_error(&a->archive,
ARCHIVE_ERRNO_FILE_FORMAT,
"Unsupported extra type (0x%x)",
(int) extra_field_id);
return ARCHIVE_FATAL;
}
return ARCHIVE_OK;
}
static int skip_unprocessed_bytes(struct archive_read* a) {
struct rar5* rar = get_context(a);
int ret;
if(rar->file.bytes_remaining) {
/* Use different skipping method in block merging mode than in
* normal mode. If merge mode is active, rar5_read_data_skip
* can't be used, because it could allow recursive use of
* merge_block() * function, and this function doesn't support
* recursive use. */
if(rar->merge_mode) {
/* Discard whole merged block. This is valid in solid
* mode as well, because the code will discard blocks
* only if those blocks are safe to discard (i.e.
* they're not FILE blocks). */
ret = consume(a, rar->file.bytes_remaining);
if(ret != ARCHIVE_OK) {
return ret;
}
rar->file.bytes_remaining = 0;
} else {
/* If we're not in merge mode, use safe skipping code.
* This will ensure we'll handle solid archives
* properly. */
ret = rar5_read_data_skip(a);
if(ret != ARCHIVE_OK) {
return ret;
}
}
}
return ARCHIVE_OK;
}
static int scan_for_signature(struct archive_read* a);
/* Base block processing function. A 'base block' is a RARv5 header block
* that tells the reader what kind of data is stored inside the block.
*
* From the birds-eye view a RAR file looks file this:
*
* <magic><base_block_1><base_block_2>...<base_block_n>
*
* There are a few types of base blocks. Those types are specified inside
* the 'switch' statement in this function. For example purposes, I'll write
* how a standard RARv5 file could look like here:
*
* <magic><MAIN><FILE><FILE><FILE><SERVICE><ENDARC>
*
* The structure above could describe an archive file with 3 files in it,
* one service "QuickOpen" block (that is ignored by this parser), and an
* end of file base block marker.
*
* If the file is stored in multiple archive files ("multiarchive"), it might
* look like this:
*
* .part01.rar: <magic><MAIN><FILE><ENDARC>
* .part02.rar: <magic><MAIN><FILE><ENDARC>
* .part03.rar: <magic><MAIN><FILE><ENDARC>
*
* This example could describe 3 RAR files that contain ONE archived file.
* Or it could describe 3 RAR files that contain 3 different files. Or 3
* RAR files than contain 2 files. It all depends what metadata is stored in
* the headers of <FILE> blocks.
*
* Each <FILE> block contains info about its size, the name of the file it's
* storing inside, and whether this FILE block is a continuation block of
* previous archive ('split before'), and is this FILE block should be
* continued in another archive ('split after'). By parsing the 'split before'
* and 'split after' flags, we're able to tell if multiple <FILE> base blocks
* are describing one file, or multiple files (with the same filename, for
* example).
*
* One thing to note is that if we're parsing the first <FILE> block, and
* we see 'split after' flag, then we need to jump over to another <FILE>
* block to be able to decompress rest of the data. To do this, we need
* to skip the <ENDARC> block, then switch to another file, then skip the
* <magic> block, <MAIN> block, and then we're standing on the proper
* <FILE> block.
*/
static int process_base_block(struct archive_read* a,
struct archive_entry* entry)
{
const size_t SMALLEST_RAR5_BLOCK_SIZE = 3;
struct rar5* rar = get_context(a);
uint32_t hdr_crc, computed_crc;
size_t raw_hdr_size = 0, hdr_size_len, hdr_size;
size_t header_id = 0;
size_t header_flags = 0;
const uint8_t* p;
int ret;
enum HEADER_TYPE {
HEAD_MARK = 0x00, HEAD_MAIN = 0x01, HEAD_FILE = 0x02,
HEAD_SERVICE = 0x03, HEAD_CRYPT = 0x04, HEAD_ENDARC = 0x05,
HEAD_UNKNOWN = 0xff,
};
/* Skip any unprocessed data for this file. */
ret = skip_unprocessed_bytes(a);
if(ret != ARCHIVE_OK)
return ret;
/* Read the expected CRC32 checksum. */
if(!read_u32(a, &hdr_crc)) {
return ARCHIVE_EOF;
}
/* Read header size. */
if(!read_var_sized(a, &raw_hdr_size, &hdr_size_len)) {
return ARCHIVE_EOF;
}
hdr_size = raw_hdr_size + hdr_size_len;
/* Sanity check, maximum header size for RAR5 is 2MB. */
if(hdr_size > (2 * 1024 * 1024)) {
archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
"Base block header is too large");
return ARCHIVE_FATAL;
}
/* Additional sanity checks to weed out invalid files. */
if(raw_hdr_size == 0 || hdr_size_len == 0 ||
hdr_size < SMALLEST_RAR5_BLOCK_SIZE)
{
archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
"Too small block encountered (%zu bytes)",
raw_hdr_size);
return ARCHIVE_FATAL;
}
/* Read the whole header data into memory, maximum memory use here is
* 2MB. */
if(!read_ahead(a, hdr_size, &p)) {
return ARCHIVE_EOF;
}
/* Verify the CRC32 of the header data. */
computed_crc = (uint32_t) crc32(0, p, (int) hdr_size);
if(computed_crc != hdr_crc) {
archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
"Header CRC error");
return ARCHIVE_FATAL;
}
/* If the checksum is OK, we proceed with parsing. */
if(ARCHIVE_OK != consume(a, hdr_size_len)) {
return ARCHIVE_EOF;
}
if(!read_var_sized(a, &header_id, NULL))
return ARCHIVE_EOF;
if(!read_var_sized(a, &header_flags, NULL))
return ARCHIVE_EOF;
rar->generic.split_after = (header_flags & HFL_SPLIT_AFTER) > 0;
rar->generic.split_before = (header_flags & HFL_SPLIT_BEFORE) > 0;
rar->generic.size = (int)hdr_size;
rar->generic.last_header_id = (int)header_id;
rar->main.endarc = 0;
/* Those are possible header ids in RARv5. */
switch(header_id) {
case HEAD_MAIN:
ret = process_head_main(a, rar, entry, header_flags);
/* Main header doesn't have any files in it, so it's
* pointless to return to the caller. Retry to next
* header, which should be HEAD_FILE/HEAD_SERVICE. */
if(ret == ARCHIVE_OK)
return ARCHIVE_RETRY;
return ret;
case HEAD_SERVICE:
ret = process_head_service(a, rar, entry, header_flags);
return ret;
case HEAD_FILE:
ret = process_head_file(a, rar, entry, header_flags);
return ret;
case HEAD_CRYPT:
archive_set_error(&a->archive,
ARCHIVE_ERRNO_FILE_FORMAT,
"Encryption is not supported");
return ARCHIVE_FATAL;
case HEAD_ENDARC:
rar->main.endarc = 1;
/* After encountering an end of file marker, we need
* to take into consideration if this archive is
* continued in another file (i.e. is it part01.rar:
* is there a part02.rar?) */
if(rar->main.volume) {
/* In case there is part02.rar, position the
* read pointer in a proper place, so we can
* resume parsing. */
ret = scan_for_signature(a);
if(ret == ARCHIVE_FATAL) {
return ARCHIVE_EOF;
} else {
if(rar->vol.expected_vol_no ==
UINT_MAX) {
archive_set_error(&a->archive,
ARCHIVE_ERRNO_FILE_FORMAT,
"Header error");
return ARCHIVE_FATAL;
}
rar->vol.expected_vol_no =
rar->main.vol_no + 1;
return ARCHIVE_OK;
}
} else {
return ARCHIVE_EOF;
}
case HEAD_MARK:
return ARCHIVE_EOF;
default:
if((header_flags & HFL_SKIP_IF_UNKNOWN) == 0) {
archive_set_error(&a->archive,
ARCHIVE_ERRNO_FILE_FORMAT,
"Header type error");
return ARCHIVE_FATAL;
} else {
/* If the block is marked as 'skip if unknown',
* do as the flag says: skip the block
* instead on failing on it. */
return ARCHIVE_RETRY;
}
}
#if !defined WIN32
// Not reached.
archive_set_error(&a->archive, ARCHIVE_ERRNO_PROGRAMMER,
"Internal unpacker error");
return ARCHIVE_FATAL;
#endif
}
static int skip_base_block(struct archive_read* a) {
int ret;
struct rar5* rar = get_context(a);
/* Create a new local archive_entry structure that will be operated on
* by header reader; operations on this archive_entry will be discarded.
*/
struct archive_entry* entry = archive_entry_new();
ret = process_base_block(a, entry);
/* Discard operations on this archive_entry structure. */
archive_entry_free(entry);
if(ret == ARCHIVE_FATAL)
return ret;
if(rar->generic.last_header_id == 2 && rar->generic.split_before > 0)
return ARCHIVE_OK;
if(ret == ARCHIVE_OK)
return ARCHIVE_RETRY;
else
return ret;
}
static int rar5_read_header(struct archive_read *a,
struct archive_entry *entry)
{
struct rar5* rar = get_context(a);
int ret;
if(rar->header_initialized == 0) {
init_header(a);
rar->header_initialized = 1;
}
if(rar->skipped_magic == 0) {
if(ARCHIVE_OK != consume(a, sizeof(rar5_signature_xor))) {
return ARCHIVE_EOF;
}
rar->skipped_magic = 1;
}
do {
ret = process_base_block(a, entry);
} while(ret == ARCHIVE_RETRY ||
(rar->main.endarc > 0 && ret == ARCHIVE_OK));
return ret;
}
static void init_unpack(struct rar5* rar) {
rar->file.calculated_crc32 = 0;
init_window_mask(rar);
free(rar->cstate.window_buf);
free(rar->cstate.filtered_buf);
if(rar->cstate.window_size > 0) {
rar->cstate.window_buf = calloc(1, rar->cstate.window_size);
rar->cstate.filtered_buf = calloc(1, rar->cstate.window_size);
} else {
rar->cstate.window_buf = NULL;
rar->cstate.filtered_buf = NULL;
}
rar->cstate.write_ptr = 0;
rar->cstate.last_write_ptr = 0;
memset(&rar->cstate.bd, 0, sizeof(rar->cstate.bd));
memset(&rar->cstate.ld, 0, sizeof(rar->cstate.ld));
memset(&rar->cstate.dd, 0, sizeof(rar->cstate.dd));
memset(&rar->cstate.ldd, 0, sizeof(rar->cstate.ldd));
memset(&rar->cstate.rd, 0, sizeof(rar->cstate.rd));
}
static void update_crc(struct rar5* rar, const uint8_t* p, size_t to_read) {
int verify_crc;
if(rar->skip_mode) {
#if defined CHECK_CRC_ON_SOLID_SKIP
verify_crc = 1;
#else
verify_crc = 0;
#endif
} else
verify_crc = 1;
if(verify_crc) {
/* Don't update CRC32 if the file doesn't have the
* `stored_crc32` info filled in. */
if(rar->file.stored_crc32 > 0) {
rar->file.calculated_crc32 =
crc32(rar->file.calculated_crc32, p, to_read);
}
/* Check if the file uses an optional BLAKE2sp checksum
* algorithm. */
if(rar->file.has_blake2 > 0) {
/* Return value of the `update` function is always 0,
* so we can explicitly ignore it here. */
(void) blake2sp_update(&rar->file.b2state, p, to_read);
}
}
}
static int create_decode_tables(uint8_t* bit_length,
struct decode_table* table, int size)
{
int code, upper_limit = 0, i, lc[16];
uint32_t decode_pos_clone[rar5_countof(table->decode_pos)];
ssize_t cur_len, quick_data_size;
memset(&lc, 0, sizeof(lc));
memset(table->decode_num, 0, sizeof(table->decode_num));
table->size = size;
table->quick_bits = size == HUFF_NC ? 10 : 7;
for(i = 0; i < size; i++) {
lc[bit_length[i] & 15]++;
}
lc[0] = 0;
table->decode_pos[0] = 0;
table->decode_len[0] = 0;
for(i = 1; i < 16; i++) {
upper_limit += lc[i];
table->decode_len[i] = upper_limit << (16 - i);
table->decode_pos[i] = table->decode_pos[i - 1] + lc[i - 1];
upper_limit <<= 1;
}
memcpy(decode_pos_clone, table->decode_pos, sizeof(decode_pos_clone));
for(i = 0; i < size; i++) {
uint8_t clen = bit_length[i] & 15;
if(clen > 0) {
int last_pos = decode_pos_clone[clen];
table->decode_num[last_pos] = i;
decode_pos_clone[clen]++;
}
}
quick_data_size = (int64_t)1 << table->quick_bits;
cur_len = 1;
for(code = 0; code < quick_data_size; code++) {
int bit_field = code << (16 - table->quick_bits);
int dist, pos;
while(cur_len < rar5_countof(table->decode_len) &&
bit_field >= table->decode_len[cur_len]) {
cur_len++;
}
table->quick_len[code] = (uint8_t) cur_len;
dist = bit_field - table->decode_len[cur_len - 1];
dist >>= (16 - cur_len);
pos = table->decode_pos[cur_len & 15] + dist;
if(cur_len < rar5_countof(table->decode_pos) && pos < size) {
table->quick_num[code] = table->decode_num[pos];
} else {
table->quick_num[code] = 0;
}
}
return ARCHIVE_OK;
}
static int decode_number(struct archive_read* a, struct decode_table* table,
const uint8_t* p, uint16_t* num)
{
int i, bits, dist, ret;
uint16_t bitfield;
uint32_t pos;
struct rar5* rar = get_context(a);
if(ARCHIVE_OK != (ret = read_bits_16(a, rar, p, &bitfield))) {
return ret;
}
bitfield &= 0xfffe;
if(bitfield < table->decode_len[table->quick_bits]) {
int code = bitfield >> (16 - table->quick_bits);
skip_bits(rar, table->quick_len[code]);
*num = table->quick_num[code];
return ARCHIVE_OK;
}
bits = 15;
for(i = table->quick_bits + 1; i < 15; i++) {
if(bitfield < table->decode_len[i]) {
bits = i;
break;
}
}
skip_bits(rar, bits);
dist = bitfield - table->decode_len[bits - 1];
dist >>= (16 - bits);
pos = table->decode_pos[bits] + dist;
if(pos >= table->size)
pos = 0;
*num = table->decode_num[pos];
return ARCHIVE_OK;
}
/* Reads and parses Huffman tables from the beginning of the block. */
static int parse_tables(struct archive_read* a, struct rar5* rar,
const uint8_t* p)
{
int ret, value, i, w, idx = 0;
uint8_t bit_length[HUFF_BC],
table[HUFF_TABLE_SIZE],
nibble_mask = 0xF0,
nibble_shift = 4;
enum { ESCAPE = 15 };
/* The data for table generation is compressed using a simple RLE-like
* algorithm when storing zeroes, so we need to unpack it first. */
for(w = 0, i = 0; w < HUFF_BC;) {
if(i >= rar->cstate.cur_block_size) {
/* Truncated data, can't continue. */
archive_set_error(&a->archive,
ARCHIVE_ERRNO_FILE_FORMAT,
"Truncated data in huffman tables");
return ARCHIVE_FATAL;
}
value = (p[i] & nibble_mask) >> nibble_shift;
if(nibble_mask == 0x0F)
++i;
nibble_mask ^= 0xFF;
nibble_shift ^= 4;
/* Values smaller than 15 is data, so we write it directly.
* Value 15 is a flag telling us that we need to unpack more
* bytes. */
if(value == ESCAPE) {
value = (p[i] & nibble_mask) >> nibble_shift;
if(nibble_mask == 0x0F)
++i;
nibble_mask ^= 0xFF;
nibble_shift ^= 4;
if(value == 0) {
/* We sometimes need to write the actual value
* of 15, so this case handles that. */
bit_length[w++] = ESCAPE;
} else {
int k;
/* Fill zeroes. */
for(k = 0; (k < value + 2) && (w < HUFF_BC);
k++) {
bit_length[w++] = 0;
}
}
} else {
bit_length[w++] = value;
}
}
rar->bits.in_addr = i;
rar->bits.bit_addr = nibble_shift ^ 4;
ret = create_decode_tables(bit_length, &rar->cstate.bd, HUFF_BC);
if(ret != ARCHIVE_OK) {
archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
"Decoding huffman tables failed");
return ARCHIVE_FATAL;
}
for(i = 0; i < HUFF_TABLE_SIZE;) {
uint16_t num;
ret = decode_number(a, &rar->cstate.bd, p, &num);
if(ret != ARCHIVE_OK) {
archive_set_error(&a->archive,
ARCHIVE_ERRNO_FILE_FORMAT,
"Decoding huffman tables failed");
return ARCHIVE_FATAL;
}
if(num < 16) {
/* 0..15: store directly */
table[i] = (uint8_t) num;
i++;
} else if(num < 18) {
/* 16..17: repeat previous code */
uint16_t n;
if(ARCHIVE_OK != (ret = read_bits_16(a, rar, p, &n)))
return ret;
if(num == 16) {
n >>= 13;
n += 3;
skip_bits(rar, 3);
} else {
n >>= 9;
n += 11;
skip_bits(rar, 7);
}
if(i > 0) {
while(n-- > 0 && i < HUFF_TABLE_SIZE) {
table[i] = table[i - 1];
i++;
}
} else {
archive_set_error(&a->archive,
ARCHIVE_ERRNO_FILE_FORMAT,
"Unexpected error when decoding "
"huffman tables");
return ARCHIVE_FATAL;
}
} else {
/* other codes: fill with zeroes `n` times */
uint16_t n;
if(ARCHIVE_OK != (ret = read_bits_16(a, rar, p, &n)))
return ret;
if(num == 18) {
n >>= 13;
n += 3;
skip_bits(rar, 3);
} else {
n >>= 9;
n += 11;
skip_bits(rar, 7);
}
while(n-- > 0 && i < HUFF_TABLE_SIZE)
table[i++] = 0;
}
}
ret = create_decode_tables(&table[idx], &rar->cstate.ld, HUFF_NC);
if(ret != ARCHIVE_OK) {
archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
"Failed to create literal table");
return ARCHIVE_FATAL;
}
idx += HUFF_NC;
ret = create_decode_tables(&table[idx], &rar->cstate.dd, HUFF_DC);
if(ret != ARCHIVE_OK) {
archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
"Failed to create distance table");
return ARCHIVE_FATAL;
}
idx += HUFF_DC;
ret = create_decode_tables(&table[idx], &rar->cstate.ldd, HUFF_LDC);
if(ret != ARCHIVE_OK) {
archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
"Failed to create lower bits of distances table");
return ARCHIVE_FATAL;
}
idx += HUFF_LDC;
ret = create_decode_tables(&table[idx], &rar->cstate.rd, HUFF_RC);
if(ret != ARCHIVE_OK) {
archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
"Failed to create repeating distances table");
return ARCHIVE_FATAL;
}
return ARCHIVE_OK;
}
/* Parses the block header, verifies its CRC byte, and saves the header
* fields inside the `hdr` pointer. */
static int parse_block_header(struct archive_read* a, const uint8_t* p,
ssize_t* block_size, struct compressed_block_header* hdr)
{
uint8_t calculated_cksum;
memcpy(hdr, p, sizeof(struct compressed_block_header));
if(bf_byte_count(hdr) > 2) {
archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
"Unsupported block header size (was %d, max is 2)",
bf_byte_count(hdr));
return ARCHIVE_FATAL;
}
/* This should probably use bit reader interface in order to be more
* future-proof. */
*block_size = 0;
switch(bf_byte_count(hdr)) {
/* 1-byte block size */
case 0:
*block_size = *(const uint8_t*) &p[2];
break;
/* 2-byte block size */
case 1:
*block_size = archive_le16dec(&p[2]);
break;
/* 3-byte block size */
case 2:
*block_size = archive_le32dec(&p[2]);
*block_size &= 0x00FFFFFF;
break;
/* Other block sizes are not supported. This case is not
* reached, because we have an 'if' guard before the switch
* that makes sure of it. */
default:
return ARCHIVE_FATAL;
}
/* Verify the block header checksum. 0x5A is a magic value and is
* always * constant. */
calculated_cksum = 0x5A
^ (uint8_t) hdr->block_flags_u8
^ (uint8_t) *block_size
^ (uint8_t) (*block_size >> 8)
^ (uint8_t) (*block_size >> 16);
if(calculated_cksum != hdr->block_cksum) {
archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
"Block checksum error: got 0x%x, expected 0x%x",
hdr->block_cksum, calculated_cksum);
return ARCHIVE_FATAL;
}
return ARCHIVE_OK;
}
/* Convenience function used during filter processing. */
static int parse_filter_data(struct archive_read* a, struct rar5* rar,
const uint8_t* p, uint32_t* filter_data)
{
int i, bytes, ret;
uint32_t data = 0;
if(ARCHIVE_OK != (ret = read_consume_bits(a, rar, p, 2, &bytes)))
return ret;
bytes++;
for(i = 0; i < bytes; i++) {
uint16_t byte;
if(ARCHIVE_OK != (ret = read_bits_16(a, rar, p, &byte))) {
return ret;
}
/* Cast to uint32_t will ensure the shift operation will not
* produce undefined result. */
data += ((uint32_t) byte >> 8) << (i * 8);
skip_bits(rar, 8);
}
*filter_data = data;
return ARCHIVE_OK;
}
/* Function is used during sanity checking. */
static int is_valid_filter_block_start(struct rar5* rar,
uint32_t start)
{
const int64_t block_start = (ssize_t) start + rar->cstate.write_ptr;
const int64_t last_bs = rar->cstate.last_block_start;
const ssize_t last_bl = rar->cstate.last_block_length;
if(last_bs == 0 || last_bl == 0) {
/* We didn't have any filters yet, so accept this offset. */
return 1;
}
if(block_start >= last_bs + last_bl) {
/* Current offset is bigger than last block's end offset, so
* accept current offset. */
return 1;
}
/* Any other case is not a normal situation and we should fail. */
return 0;
}
/* The function will create a new filter, read its parameters from the input
* stream and add it to the filter collection. */
static int parse_filter(struct archive_read* ar, const uint8_t* p) {
uint32_t block_start, block_length;
uint16_t filter_type;
struct filter_info* filt = NULL;
struct rar5* rar = get_context(ar);
int ret;
/* Read the parameters from the input stream. */
if(ARCHIVE_OK != (ret = parse_filter_data(ar, rar, p, &block_start)))
return ret;
if(ARCHIVE_OK != (ret = parse_filter_data(ar, rar, p, &block_length)))
return ret;
if(ARCHIVE_OK != (ret = read_bits_16(ar, rar, p, &filter_type)))
return ret;
filter_type >>= 13;
skip_bits(rar, 3);
/* Perform some sanity checks on this filter parameters. Note that we
* allow only DELTA, E8/E9 and ARM filters here, because rest of
* filters are not used in RARv5. */
if(block_length < 4 ||
block_length > 0x400000 ||
filter_type > FILTER_ARM ||
!is_valid_filter_block_start(rar, block_start))
{
archive_set_error(&ar->archive, ARCHIVE_ERRNO_FILE_FORMAT,
"Invalid filter encountered");
return ARCHIVE_FATAL;
}
/* Allocate a new filter. */
filt = add_new_filter(rar);
if(filt == NULL) {
archive_set_error(&ar->archive, ENOMEM,
"Can't allocate memory for a filter descriptor.");
return ARCHIVE_FATAL;
}
filt->type = filter_type;
filt->block_start = rar->cstate.write_ptr + block_start;
filt->block_length = block_length;
rar->cstate.last_block_start = filt->block_start;
rar->cstate.last_block_length = filt->block_length;
/* Read some more data in case this is a DELTA filter. Other filter
* types don't require any additional data over what was already
* read. */
if(filter_type == FILTER_DELTA) {
int channels;
if(ARCHIVE_OK != (ret = read_consume_bits(ar, rar, p, 5, &channels)))
return ret;
filt->channels = channels + 1;
}
return ARCHIVE_OK;
}
static int decode_code_length(struct archive_read* a, struct rar5* rar,
const uint8_t* p, uint16_t code)
{
int lbits, length = 2;
if(code < 8) {
lbits = 0;
length += code;
} else {
lbits = code / 4 - 1;
length += (4 | (code & 3)) << lbits;
}
if(lbits > 0) {
int add;
if(ARCHIVE_OK != read_consume_bits(a, rar, p, lbits, &add))
return -1;
length += add;
}
return length;
}
static int copy_string(struct archive_read* a, int len, int dist) {
struct rar5* rar = get_context(a);
const uint64_t cmask = rar->cstate.window_mask;
const uint64_t write_ptr = rar->cstate.write_ptr +
rar->cstate.solid_offset;
int i;
if (rar->cstate.window_buf == NULL)
return ARCHIVE_FATAL;
/* The unpacker spends most of the time in this function. It would be
* a good idea to introduce some optimizations here.
*
* Just remember that this loop treats buffers that overlap differently
* than buffers that do not overlap. This is why a simple memcpy(3)
* call will not be enough. */
for(i = 0; i < len; i++) {
const ssize_t write_idx = (write_ptr + i) & cmask;
const ssize_t read_idx = (write_ptr + i - dist) & cmask;
rar->cstate.window_buf[write_idx] =
rar->cstate.window_buf[read_idx];
}
rar->cstate.write_ptr += len;
return ARCHIVE_OK;
}
static int do_uncompress_block(struct archive_read* a, const uint8_t* p) {
struct rar5* rar = get_context(a);
uint16_t num;
int ret;
const uint64_t cmask = rar->cstate.window_mask;
const struct compressed_block_header* hdr = &rar->last_block_hdr;
const uint8_t bit_size = 1 + bf_bit_size(hdr);
while(1) {
if(rar->cstate.write_ptr - rar->cstate.last_write_ptr >
(rar->cstate.window_size >> 1)) {
/* Don't allow growing data by more than half of the
* window size at a time. In such case, break the loop;
* next call to this function will continue processing
* from this moment. */
break;
}
if(rar->bits.in_addr > rar->cstate.cur_block_size - 1 ||
(rar->bits.in_addr == rar->cstate.cur_block_size - 1 &&
rar->bits.bit_addr >= bit_size))
{
/* If the program counter is here, it means the
* function has finished processing the block. */
rar->cstate.block_parsing_finished = 1;
break;
}
/* Decode the next literal. */
if(ARCHIVE_OK != decode_number(a, &rar->cstate.ld, p, &num)) {
return ARCHIVE_EOF;
}
/* Num holds a decompression literal, or 'command code'.
*
* - Values lower than 256 are just bytes. Those codes
* can be stored in the output buffer directly.
*
* - Code 256 defines a new filter, which is later used to
* ransform the data block accordingly to the filter type.
* The data block needs to be fully uncompressed first.
*
* - Code bigger than 257 and smaller than 262 define
* a repetition pattern that should be copied from
* an already uncompressed chunk of data.
*/
if(num < 256) {
/* Directly store the byte. */
int64_t write_idx = rar->cstate.solid_offset +
rar->cstate.write_ptr++;
rar->cstate.window_buf[write_idx & cmask] =
(uint8_t) num;
continue;
} else if(num >= 262) {
uint16_t dist_slot;
int len = decode_code_length(a, rar, p, num - 262),
dbits,
dist = 1;
if(len == -1) {
archive_set_error(&a->archive,
ARCHIVE_ERRNO_PROGRAMMER,
"Failed to decode the code length");
return ARCHIVE_FATAL;
}
if(ARCHIVE_OK != decode_number(a, &rar->cstate.dd, p,
&dist_slot))
{
archive_set_error(&a->archive,
ARCHIVE_ERRNO_PROGRAMMER,
"Failed to decode the distance slot");
return ARCHIVE_FATAL;
}
if(dist_slot < 4) {
dbits = 0;
dist += dist_slot;
} else {
dbits = dist_slot / 2 - 1;
/* Cast to uint32_t will make sure the shift
* left operation won't produce undefined
* result. Then, the uint32_t type will
* be implicitly casted to int. */
dist += (uint32_t) (2 |
(dist_slot & 1)) << dbits;
}
if(dbits > 0) {
if(dbits >= 4) {
uint32_t add = 0;
uint16_t low_dist;
if(dbits > 4) {
if(ARCHIVE_OK != (ret = read_bits_32(
a, rar, p, &add))) {
/* Return EOF if we
* can't read more
* data. */
return ret;
}
skip_bits(rar, dbits - 4);
add = (add >> (
36 - dbits)) << 4;
dist += add;
}
if(ARCHIVE_OK != decode_number(a,
&rar->cstate.ldd, p, &low_dist))
{
archive_set_error(&a->archive,
ARCHIVE_ERRNO_PROGRAMMER,
"Failed to decode the "
"distance slot");
return ARCHIVE_FATAL;
}
if(dist >= INT_MAX - low_dist - 1) {
/* This only happens in
* invalid archives. */
archive_set_error(&a->archive,
ARCHIVE_ERRNO_FILE_FORMAT,
"Distance pointer "
"overflow");
return ARCHIVE_FATAL;
}
dist += low_dist;
} else {
/* dbits is one of [0,1,2,3] */
int add;
if(ARCHIVE_OK != (ret = read_consume_bits(a, rar,
p, dbits, &add))) {
/* Return EOF if we can't read
* more data. */
return ret;
}
dist += add;
}
}
if(dist > 0x100) {
len++;
if(dist > 0x2000) {
len++;
if(dist > 0x40000) {
len++;
}
}
}
dist_cache_push(rar, dist);
rar->cstate.last_len = len;
if(ARCHIVE_OK != copy_string(a, len, dist))
return ARCHIVE_FATAL;
continue;
} else if(num == 256) {
/* Create a filter. */
ret = parse_filter(a, p);
if(ret != ARCHIVE_OK)
return ret;
continue;
} else if(num == 257) {
if(rar->cstate.last_len != 0) {
if(ARCHIVE_OK != copy_string(a,
rar->cstate.last_len,
rar->cstate.dist_cache[0]))
{
return ARCHIVE_FATAL;
}
}
continue;
} else {
/* num < 262 */
const int idx = num - 258;
const int dist = dist_cache_touch(rar, idx);
uint16_t len_slot;
int len;
if(ARCHIVE_OK != decode_number(a, &rar->cstate.rd, p,
&len_slot)) {
return ARCHIVE_FATAL;
}
len = decode_code_length(a, rar, p, len_slot);
if (len == -1) {
return ARCHIVE_FATAL;
}
rar->cstate.last_len = len;
if(ARCHIVE_OK != copy_string(a, len, dist))
return ARCHIVE_FATAL;
continue;
}
}
return ARCHIVE_OK;
}
/* Binary search for the RARv5 signature. */
static int scan_for_signature(struct archive_read* a) {
const uint8_t* p;
const int chunk_size = 512;
ssize_t i;
char signature[sizeof(rar5_signature_xor)];
/* If we're here, it means we're on an 'unknown territory' data.
* There's no indication what kind of data we're reading here.
* It could be some text comment, any kind of binary data,
* digital sign, dragons, etc.
*
* We want to find a valid RARv5 magic header inside this unknown
* data. */
/* Is it possible in libarchive to just skip everything until the
* end of the file? If so, it would be a better approach than the
* current implementation of this function. */
rar5_signature(signature);
while(1) {
if(!read_ahead(a, chunk_size, &p))
return ARCHIVE_EOF;
for(i = 0; i < chunk_size - (int)sizeof(rar5_signature_xor);
i++) {
if(memcmp(&p[i], signature,
sizeof(rar5_signature_xor)) == 0) {
/* Consume the number of bytes we've used to
* search for the signature, as well as the
* number of bytes used by the signature
* itself. After this we should be standing
* on a valid base block header. */
(void) consume(a,
i + sizeof(rar5_signature_xor));
return ARCHIVE_OK;
}
}
consume(a, chunk_size);
}
return ARCHIVE_FATAL;
}
/* This function will switch the multivolume archive file to another file,
* i.e. from part03 to part 04. */
static int advance_multivolume(struct archive_read* a) {
int lret;
struct rar5* rar = get_context(a);
/* A small state machine that will skip unnecessary data, needed to
* switch from one multivolume to another. Such skipping is needed if
* we want to be an stream-oriented (instead of file-oriented)
* unpacker.
*
* The state machine starts with `rar->main.endarc` == 0. It also
* assumes that current stream pointer points to some base block
* header.
*
* The `endarc` field is being set when the base block parsing
* function encounters the 'end of archive' marker.
*/
while(1) {
if(rar->main.endarc == 1) {
int looping = 1;
rar->main.endarc = 0;
while(looping) {
lret = skip_base_block(a);
switch(lret) {
case ARCHIVE_RETRY:
/* Continue looping. */
break;
case ARCHIVE_OK:
/* Break loop. */
looping = 0;
break;
default:
/* Forward any errors to the
* caller. */
return lret;
}
}
break;
} else {
/* Skip current base block. In order to properly skip
* it, we really need to simply parse it and discard
* the results. */
lret = skip_base_block(a);
if(lret == ARCHIVE_FATAL || lret == ARCHIVE_FAILED)
return lret;
/* The `skip_base_block` function tells us if we
* should continue with skipping, or we should stop
* skipping. We're trying to skip everything up to
* a base FILE block. */
if(lret != ARCHIVE_RETRY) {
/* If there was an error during skipping, or we
* have just skipped a FILE base block... */
if(rar->main.endarc == 0) {
return lret;
} else {
continue;
}
}
}
}
return ARCHIVE_OK;
}
/* Merges the partial block from the first multivolume archive file, and
* partial block from the second multivolume archive file. The result is
* a chunk of memory containing the whole block, and the stream pointer
* is advanced to the next block in the second multivolume archive file. */
static int merge_block(struct archive_read* a, ssize_t block_size,
const uint8_t** p)
{
struct rar5* rar = get_context(a);
ssize_t cur_block_size, partial_offset = 0;
const uint8_t* lp;
int ret;
if(rar->merge_mode) {
archive_set_error(&a->archive, ARCHIVE_ERRNO_PROGRAMMER,
"Recursive merge is not allowed");
return ARCHIVE_FATAL;
}
/* Set a flag that we're in the switching mode. */
rar->cstate.switch_multivolume = 1;
/* Reallocate the memory which will hold the whole block. */
if(rar->vol.push_buf)
free((void*) rar->vol.push_buf);
/* Increasing the allocation block by 8 is due to bit reading functions,
* which are using additional 2 or 4 bytes. Allocating the block size
* by exact value would make bit reader perform reads from invalid
* memory block when reading the last byte from the buffer. */
rar->vol.push_buf = malloc(block_size + 8);
if(!rar->vol.push_buf) {
archive_set_error(&a->archive, ENOMEM,
"Can't allocate memory for a merge block buffer.");
return ARCHIVE_FATAL;
}
/* Valgrind complains if the extension block for bit reader is not
* initialized, so initialize it. */
memset(&rar->vol.push_buf[block_size], 0, 8);
/* A single block can span across multiple multivolume archive files,
* so we use a loop here. This loop will consume enough multivolume
* archive files until the whole block is read. */
while(1) {
/* Get the size of current block chunk in this multivolume
* archive file and read it. */
cur_block_size = rar5_min(rar->file.bytes_remaining,
block_size - partial_offset);
if(cur_block_size == 0) {
archive_set_error(&a->archive,
ARCHIVE_ERRNO_FILE_FORMAT,
"Encountered block size == 0 during block merge");
return ARCHIVE_FATAL;
}
if(!read_ahead(a, cur_block_size, &lp))
return ARCHIVE_EOF;
/* Sanity check; there should never be a situation where this
* function reads more data than the block's size. */
if(partial_offset + cur_block_size > block_size) {
archive_set_error(&a->archive,
ARCHIVE_ERRNO_PROGRAMMER,
"Consumed too much data when merging blocks.");
return ARCHIVE_FATAL;
}
/* Merge previous block chunk with current block chunk,
* or create first block chunk if this is our first
* iteration. */
memcpy(&rar->vol.push_buf[partial_offset], lp, cur_block_size);
/* Advance the stream read pointer by this block chunk size. */
if(ARCHIVE_OK != consume(a, cur_block_size))
return ARCHIVE_EOF;
/* Update the pointers. `partial_offset` contains information
* about the sum of merged block chunks. */
partial_offset += cur_block_size;
rar->file.bytes_remaining -= cur_block_size;
/* If `partial_offset` is the same as `block_size`, this means
* we've merged all block chunks and we have a valid full
* block. */
if(partial_offset == block_size) {
break;
}
/* If we don't have any bytes to read, this means we should
* switch to another multivolume archive file. */
if(rar->file.bytes_remaining == 0) {
rar->merge_mode++;
ret = advance_multivolume(a);
rar->merge_mode--;
if(ret != ARCHIVE_OK) {
return ret;
}
}
}
*p = rar->vol.push_buf;
/* If we're here, we can resume unpacking by processing the block
* pointed to by the `*p` memory pointer. */
return ARCHIVE_OK;
}
static int process_block(struct archive_read* a) {
const uint8_t* p;
struct rar5* rar = get_context(a);
int ret;
/* If we don't have any data to be processed, this most probably means
* we need to switch to the next volume. */
if(rar->main.volume && rar->file.bytes_remaining == 0) {
ret = advance_multivolume(a);
if(ret != ARCHIVE_OK)
return ret;
}
if(rar->cstate.block_parsing_finished) {
ssize_t block_size;
ssize_t to_skip;
ssize_t cur_block_size;
/* The header size won't be bigger than 6 bytes. */
if(!read_ahead(a, 6, &p)) {
/* Failed to prefetch data block header. */
return ARCHIVE_EOF;
}
/*
* Read block_size by parsing block header. Validate the header
* by calculating CRC byte stored inside the header. Size of
* the header is not constant (block size can be stored either
* in 1 or 2 bytes), that's why block size is left out from the
* `compressed_block_header` structure and returned by
* `parse_block_header` as the second argument. */
ret = parse_block_header(a, p, &block_size,
&rar->last_block_hdr);
if(ret != ARCHIVE_OK) {
return ret;
}
/* Skip block header. Next data is huffman tables,
* if present. */
to_skip = sizeof(struct compressed_block_header) +
bf_byte_count(&rar->last_block_hdr) + 1;
if(ARCHIVE_OK != consume(a, to_skip))
return ARCHIVE_EOF;
rar->file.bytes_remaining -= to_skip;
/* The block size gives information about the whole block size,
* but the block could be stored in split form when using
* multi-volume archives. In this case, the block size will be
* bigger than the actual data stored in this file. Remaining
* part of the data will be in another file. */
cur_block_size =
rar5_min(rar->file.bytes_remaining, block_size);
if(block_size > rar->file.bytes_remaining) {
/* If current blocks' size is bigger than our data
* size, this means we have a multivolume archive.
* In this case, skip all base headers until the end
* of the file, proceed to next "partXXX.rar" volume,
* find its signature, skip all headers up to the first
* FILE base header, and continue from there.
*
* Note that `merge_block` will update the `rar`
* context structure quite extensively. */
ret = merge_block(a, block_size, &p);
if(ret != ARCHIVE_OK) {
return ret;
}
cur_block_size = block_size;
/* Current stream pointer should be now directly
* *after* the block that spanned through multiple
* archive files. `p` pointer should have the data of
* the *whole* block (merged from partial blocks
* stored in multiple archives files). */
} else {
rar->cstate.switch_multivolume = 0;
/* Read the whole block size into memory. This can take
* up to 8 megabytes of memory in theoretical cases.
* Might be worth to optimize this and use a standard
* chunk of 4kb's. */
if(!read_ahead(a, 4 + cur_block_size, &p)) {
/* Failed to prefetch block data. */
return ARCHIVE_EOF;
}
}
rar->cstate.block_buf = p;
rar->cstate.cur_block_size = cur_block_size;
rar->cstate.block_parsing_finished = 0;
rar->bits.in_addr = 0;
rar->bits.bit_addr = 0;
if(bf_is_table_present(&rar->last_block_hdr)) {
/* Load Huffman tables. */
ret = parse_tables(a, rar, p);
if(ret != ARCHIVE_OK) {
/* Error during decompression of Huffman
* tables. */
return ret;
}
}
} else {
/* Block parsing not finished, reuse previous memory buffer. */
p = rar->cstate.block_buf;
}
/* Uncompress the block, or a part of it, depending on how many bytes
* will be generated by uncompressing the block.
*
* In case too many bytes will be generated, calling this function
* again will resume the uncompression operation. */
ret = do_uncompress_block(a, p);
if(ret != ARCHIVE_OK) {
return ret;
}
if(rar->cstate.block_parsing_finished &&
rar->cstate.switch_multivolume == 0 &&
rar->cstate.cur_block_size > 0)
{
/* If we're processing a normal block, consume the whole
* block. We can do this because we've already read the whole
* block to memory. */
if(ARCHIVE_OK != consume(a, rar->cstate.cur_block_size))
return ARCHIVE_FATAL;
rar->file.bytes_remaining -= rar->cstate.cur_block_size;
} else if(rar->cstate.switch_multivolume) {
/* Don't consume the block if we're doing multivolume
* processing. The volume switching function will consume
* the proper count of bytes instead. */
rar->cstate.switch_multivolume = 0;
}
return ARCHIVE_OK;
}
/* Pops the `buf`, `size` and `offset` from the "data ready" stack.
*
* Returns ARCHIVE_OK when those arguments can be used, ARCHIVE_RETRY
* when there is no data on the stack. */
static int use_data(struct rar5* rar, const void** buf, size_t* size,
int64_t* offset)
{
int i;
for(i = 0; i < rar5_countof(rar->cstate.dready); i++) {
struct data_ready *d = &rar->cstate.dready[i];
if(d->used) {
if(buf) *buf = d->buf;
if(size) *size = d->size;
if(offset) *offset = d->offset;
d->used = 0;
return ARCHIVE_OK;
}
}
return ARCHIVE_RETRY;
}
/* Pushes the `buf`, `size` and `offset` arguments to the rar->cstate.dready
* FIFO stack. Those values will be popped from this stack by the `use_data`
* function. */
static int push_data_ready(struct archive_read* a, struct rar5* rar,
const uint8_t* buf, size_t size, int64_t offset)
{
int i;
/* Don't push if we're in skip mode. This is needed because solid
* streams need full processing even if we're skipping data. After
* fully processing the stream, we need to discard the generated bytes,
* because we're interested only in the side effect: building up the
* internal window circular buffer. This window buffer will be used
* later during unpacking of requested data. */
if(rar->skip_mode)
return ARCHIVE_OK;
/* Sanity check. */
if(offset != rar->file.last_offset + rar->file.last_size) {
archive_set_error(&a->archive, ARCHIVE_ERRNO_PROGRAMMER,
"Sanity check error: output stream is not continuous");
return ARCHIVE_FATAL;
}
for(i = 0; i < rar5_countof(rar->cstate.dready); i++) {
struct data_ready* d = &rar->cstate.dready[i];
if(!d->used) {
d->used = 1;
d->buf = buf;
d->size = size;
d->offset = offset;
/* These fields are used only in sanity checking. */
rar->file.last_offset = offset;
rar->file.last_size = size;
/* Calculate the checksum of this new block before
* submitting data to libarchive's engine. */
update_crc(rar, d->buf, d->size);
return ARCHIVE_OK;
}
}
/* Program counter will reach this code if the `rar->cstate.data_ready`
* stack will be filled up so that no new entries will be allowed. The
* code shouldn't allow such situation to occur. So we treat this case
* as an internal error. */
archive_set_error(&a->archive, ARCHIVE_ERRNO_PROGRAMMER,
"Error: premature end of data_ready stack");
return ARCHIVE_FATAL;
}
/* This function uncompresses the data that is stored in the <FILE> base
* block.
*
* The FILE base block looks like this:
*
* <header><huffman tables><block_1><block_2>...<block_n>
*
* The <header> is a block header, that is parsed in parse_block_header().
* It's a "compressed_block_header" structure, containing metadata needed
* to know when we should stop looking for more <block_n> blocks.
*
* <huffman tables> contain data needed to set up the huffman tables, needed
* for the actual decompression.
*
* Each <block_n> consists of series of literals:
*
* <literal><literal><literal>...<literal>
*
* Those literals generate the uncompression data. They operate on a circular
* buffer, sometimes writing raw data into it, sometimes referencing
* some previous data inside this buffer, and sometimes declaring a filter
* that will need to be executed on the data stored in the circular buffer.
* It all depends on the literal that is used.
*
* Sometimes blocks produce output data, sometimes they don't. For example, for
* some huge files that use lots of filters, sometimes a block is filled with
* only filter declaration literals. Such blocks won't produce any data in the
* circular buffer.
*
* Sometimes blocks will produce 4 bytes of data, and sometimes 1 megabyte,
* because a literal can reference previously decompressed data. For example,
* there can be a literal that says: 'append a byte 0xFE here', and after
* it another literal can say 'append 1 megabyte of data from circular buffer
* offset 0x12345'. This is how RAR format handles compressing repeated
* patterns.
*
* The RAR compressor creates those literals and the actual efficiency of
* compression depends on what those literals are. The literals can also
* be seen as a kind of a non-turing-complete virtual machine that simply
* tells the decompressor what it should do.
* */
static int do_uncompress_file(struct archive_read* a) {
struct rar5* rar = get_context(a);
int ret;
int64_t max_end_pos;
if(!rar->cstate.initialized) {
/* Don't perform full context reinitialization if we're
* processing a solid archive. */
if(!rar->main.solid || !rar->cstate.window_buf) {
init_unpack(rar);
}
rar->cstate.initialized = 1;
}
/* Don't allow extraction if window_size is invalid. */
if(rar->cstate.window_size == 0) {
archive_set_error(&a->archive,
ARCHIVE_ERRNO_FILE_FORMAT,
"Invalid window size declaration in this file");
/* This should never happen in valid files. */
return ARCHIVE_FATAL;
}
if(rar->cstate.all_filters_applied == 1) {
/* We use while(1) here, but standard case allows for just 1
* iteration. The loop will iterate if process_block() didn't
* generate any data at all. This can happen if the block
* contains only filter definitions (this is common in big
* files). */
while(1) {
ret = process_block(a);
if(ret == ARCHIVE_EOF || ret == ARCHIVE_FATAL)
return ret;
if(rar->cstate.last_write_ptr ==
rar->cstate.write_ptr) {
/* The block didn't generate any new data,
* so just process a new block. */
continue;
}
/* The block has generated some new data, so break
* the loop. */
break;
}
}
/* Try to run filters. If filters won't be applied, it means that
* insufficient data was generated. */
ret = apply_filters(a);
if(ret == ARCHIVE_RETRY) {
return ARCHIVE_OK;
} else if(ret == ARCHIVE_FATAL) {
return ARCHIVE_FATAL;
}
/* If apply_filters() will return ARCHIVE_OK, we can continue here. */
if(cdeque_size(&rar->cstate.filters) > 0) {
/* Check if we can write something before hitting first
* filter. */
struct filter_info* flt;
/* Get the block_start offset from the first filter. */
if(CDE_OK != cdeque_front(&rar->cstate.filters,
cdeque_filter_p(&flt)))
{
archive_set_error(&a->archive,
ARCHIVE_ERRNO_PROGRAMMER,
"Can't read first filter");
return ARCHIVE_FATAL;
}
max_end_pos = rar5_min(flt->block_start,
rar->cstate.write_ptr);
} else {
/* There are no filters defined, or all filters were applied.
* This means we can just store the data without any
* postprocessing. */
max_end_pos = rar->cstate.write_ptr;
}
if(max_end_pos == rar->cstate.last_write_ptr) {
/* We can't write anything yet. The block uncompression
* function did not generate enough data, and no filter can be
* applied. At the same time we don't have any data that can be
* stored without filter postprocessing. This means we need to
* wait for more data to be generated, so we can apply the
* filters.
*
* Signal the caller that we need more data to be able to do
* anything.
*/
return ARCHIVE_RETRY;
} else {
/* We can write the data before hitting the first filter.
* So let's do it. The push_window_data() function will
* effectively return the selected data block to the user
* application. */
push_window_data(a, rar, rar->cstate.last_write_ptr,
max_end_pos);
rar->cstate.last_write_ptr = max_end_pos;
}
return ARCHIVE_OK;
}
static int uncompress_file(struct archive_read* a) {
int ret;
while(1) {
/* Sometimes the uncompression function will return a
* 'retry' signal. If this will happen, we have to retry
* the function. */
ret = do_uncompress_file(a);
if(ret != ARCHIVE_RETRY)
return ret;
}
}
static int do_unstore_file(struct archive_read* a,
struct rar5* rar, const void** buf, size_t* size, int64_t* offset)
{
size_t to_read;
const uint8_t* p;
if(rar->file.bytes_remaining == 0 && rar->main.volume > 0 &&
rar->generic.split_after > 0)
{
int ret;
rar->cstate.switch_multivolume = 1;
ret = advance_multivolume(a);
rar->cstate.switch_multivolume = 0;
if(ret != ARCHIVE_OK) {
/* Failed to advance to next multivolume archive
* file. */
return ret;
}
}
to_read = rar5_min(rar->file.bytes_remaining, 64 * 1024);
if(to_read == 0) {
return ARCHIVE_EOF;
}
if(!read_ahead(a, to_read, &p)) {
archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
"I/O error when unstoring file");
return ARCHIVE_FATAL;
}
if(ARCHIVE_OK != consume(a, to_read)) {
return ARCHIVE_EOF;
}
if(buf) *buf = p;
if(size) *size = to_read;
if(offset) *offset = rar->cstate.last_unstore_ptr;
rar->file.bytes_remaining -= to_read;
rar->cstate.last_unstore_ptr += to_read;
update_crc(rar, p, to_read);
return ARCHIVE_OK;
}
static int do_unpack(struct archive_read* a, struct rar5* rar,
const void** buf, size_t* size, int64_t* offset)
{
enum COMPRESSION_METHOD {
STORE = 0, FASTEST = 1, FAST = 2, NORMAL = 3, GOOD = 4,
BEST = 5
};
if(rar->file.service > 0) {
return do_unstore_file(a, rar, buf, size, offset);
} else {
switch(rar->cstate.method) {
case STORE:
return do_unstore_file(a, rar, buf, size,
offset);
case FASTEST:
/* fallthrough */
case FAST:
/* fallthrough */
case NORMAL:
/* fallthrough */
case GOOD:
/* fallthrough */
case BEST:
return uncompress_file(a);
default:
archive_set_error(&a->archive,
ARCHIVE_ERRNO_FILE_FORMAT,
"Compression method not supported: 0x%x",
rar->cstate.method);
return ARCHIVE_FATAL;
}
}
#if !defined WIN32
/* Not reached. */
return ARCHIVE_OK;
#endif
}
static int verify_checksums(struct archive_read* a) {
int verify_crc;
struct rar5* rar = get_context(a);
/* Check checksums only when actually unpacking the data. There's no
* need to calculate checksum when we're skipping data in solid archives
* (skipping in solid archives is the same thing as unpacking compressed
* data and discarding the result). */
if(!rar->skip_mode) {
/* Always check checksums if we're not in skip mode */
verify_crc = 1;
} else {
/* We can override the logic above with a compile-time option
* NO_CRC_ON_SOLID_SKIP. This option is used during debugging,
* and it will check checksums of unpacked data even when
* we're skipping it. */
#if defined CHECK_CRC_ON_SOLID_SKIP
/* Debug case */
verify_crc = 1;
#else
/* Normal case */
verify_crc = 0;
#endif
}
if(verify_crc) {
/* During unpacking, on each unpacked block we're calling the
* update_crc() function. Since we are here, the unpacking
* process is already over and we can check if calculated
* checksum (CRC32 or BLAKE2sp) is the same as what is stored
* in the archive. */
if(rar->file.stored_crc32 > 0) {
/* Check CRC32 only when the file contains a CRC32
* value for this file. */
if(rar->file.calculated_crc32 !=
rar->file.stored_crc32) {
/* Checksums do not match; the unpacked file
* is corrupted. */
DEBUG_CODE {
printf("Checksum error: CRC32 "
"(was: %08" PRIx32 ", expected: %08" PRIx32 ")\n",
rar->file.calculated_crc32,
rar->file.stored_crc32);
}
#ifndef DONT_FAIL_ON_CRC_ERROR
archive_set_error(&a->archive,
ARCHIVE_ERRNO_FILE_FORMAT,
"Checksum error: CRC32");
return ARCHIVE_FATAL;
#endif
} else {
DEBUG_CODE {
printf("Checksum OK: CRC32 "
"(%08" PRIx32 "/%08" PRIx32 ")\n",
rar->file.stored_crc32,
rar->file.calculated_crc32);
}
}
}
if(rar->file.has_blake2 > 0) {
/* BLAKE2sp is an optional checksum algorithm that is
* added to RARv5 archives when using the `-htb` switch
* during creation of archive.
*
* We now finalize the hash calculation by calling the
* `final` function. This will generate the final hash
* value we can use to compare it with the BLAKE2sp
* checksum that is stored in the archive.
*
* The return value of this `final` function is not
* very helpful, as it guards only against improper use.
* This is why we're explicitly ignoring it. */
uint8_t b2_buf[32];
(void) blake2sp_final(&rar->file.b2state, b2_buf, 32);
if(memcmp(&rar->file.blake2sp, b2_buf, 32) != 0) {
#ifndef DONT_FAIL_ON_CRC_ERROR
archive_set_error(&a->archive,
ARCHIVE_ERRNO_FILE_FORMAT,
"Checksum error: BLAKE2");
return ARCHIVE_FATAL;
#endif
}
}
}
/* Finalization for this file has been successfully completed. */
return ARCHIVE_OK;
}
static int verify_global_checksums(struct archive_read* a) {
return verify_checksums(a);
}
/*
* Decryption function for the magic signature pattern. Check the comment near
* the `rar5_signature_xor` symbol to read the rationale behind this.
*/
static void rar5_signature(char *buf) {
size_t i;
for(i = 0; i < sizeof(rar5_signature_xor); i++) {
buf[i] = rar5_signature_xor[i] ^ 0xA1;
}
}
static int rar5_read_data(struct archive_read *a, const void **buff,
size_t *size, int64_t *offset) {
int ret;
struct rar5* rar = get_context(a);
if (size)
*size = 0;
if(rar->file.dir > 0) {
/* Don't process any data if this file entry was declared
* as a directory. This is needed, because entries marked as
* directory doesn't have any dictionary buffer allocated, so
* it's impossible to perform any decompression. */
archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
"Can't decompress an entry marked as a directory");
return ARCHIVE_FAILED;
}
if(!rar->skip_mode && (rar->cstate.last_write_ptr > rar->file.unpacked_size)) {
archive_set_error(&a->archive, ARCHIVE_ERRNO_PROGRAMMER,
"Unpacker has written too many bytes");
return ARCHIVE_FATAL;
}
ret = use_data(rar, buff, size, offset);
if(ret == ARCHIVE_OK) {
return ret;
}
if(rar->file.eof == 1) {
return ARCHIVE_EOF;
}
ret = do_unpack(a, rar, buff, size, offset);
if(ret != ARCHIVE_OK) {
return ret;
}
if(rar->file.bytes_remaining == 0 &&
rar->cstate.last_write_ptr == rar->file.unpacked_size)
{
/* If all bytes of current file were processed, run
* finalization.
*
* Finalization will check checksum against proper values. If
* some of the checksums will not match, we'll return an error
* value in the last `archive_read_data` call to signal an error
* to the user. */
rar->file.eof = 1;
return verify_global_checksums(a);
}
return ARCHIVE_OK;
}
static int rar5_read_data_skip(struct archive_read *a) {
struct rar5* rar = get_context(a);
if(rar->main.solid) {
/* In solid archives, instead of skipping the data, we need to
* extract it, and dispose the result. The side effect of this
* operation will be setting up the initial window buffer state
* needed to be able to extract the selected file. */
int ret;
/* Make sure to process all blocks in the compressed stream. */
while(rar->file.bytes_remaining > 0) {
/* Setting the "skip mode" will allow us to skip
* checksum checks during data skipping. Checking the
* checksum of skipped data isn't really necessary and
* it's only slowing things down.
*
* This is incremented instead of setting to 1 because
* this data skipping function can be called
* recursively. */
rar->skip_mode++;
/* We're disposing 1 block of data, so we use triple
* NULLs in arguments. */
ret = rar5_read_data(a, NULL, NULL, NULL);
/* Turn off "skip mode". */
rar->skip_mode--;
if(ret < 0 || ret == ARCHIVE_EOF) {
/* Propagate any potential error conditions
* to the caller. */
return ret;
}
}
} else {
/* In standard archives, we can just jump over the compressed
* stream. Each file in non-solid archives starts from an empty
* window buffer. */
if(ARCHIVE_OK != consume(a, rar->file.bytes_remaining)) {
return ARCHIVE_FATAL;
}
rar->file.bytes_remaining = 0;
}
return ARCHIVE_OK;
}
static int64_t rar5_seek_data(struct archive_read *a, int64_t offset,
int whence)
{
(void) a;
(void) offset;
(void) whence;
/* We're a streaming unpacker, and we don't support seeking. */
return ARCHIVE_FATAL;
}
static int rar5_cleanup(struct archive_read *a) {
struct rar5* rar = get_context(a);
free(rar->cstate.window_buf);
free(rar->cstate.filtered_buf);
free(rar->vol.push_buf);
free_filters(rar);
cdeque_free(&rar->cstate.filters);
free(rar);
a->format->data = NULL;
return ARCHIVE_OK;
}
static int rar5_capabilities(struct archive_read * a) {
(void) a;
return 0;
}
static int rar5_has_encrypted_entries(struct archive_read *_a) {
(void) _a;
/* Unsupported for now. */
return ARCHIVE_READ_FORMAT_ENCRYPTION_UNSUPPORTED;
}
static int rar5_init(struct rar5* rar) {
memset(rar, 0, sizeof(struct rar5));
if(CDE_OK != cdeque_init(&rar->cstate.filters, 8192))
return ARCHIVE_FATAL;
return ARCHIVE_OK;
}
int archive_read_support_format_rar5(struct archive *_a) {
struct archive_read* ar;
int ret;
struct rar5* rar;
if(ARCHIVE_OK != (ret = get_archive_read(_a, &ar)))
return ret;
rar = malloc(sizeof(*rar));
if(rar == NULL) {
archive_set_error(&ar->archive, ENOMEM,
"Can't allocate rar5 data");
return ARCHIVE_FATAL;
}
if(ARCHIVE_OK != rar5_init(rar)) {
archive_set_error(&ar->archive, ENOMEM,
"Can't allocate rar5 filter buffer");
free(rar);
return ARCHIVE_FATAL;
}
ret = __archive_read_register_format(ar,
rar,
"rar5",
rar5_bid,
rar5_options,
rar5_read_header,
rar5_read_data,
rar5_read_data_skip,
rar5_seek_data,
rar5_cleanup,
rar5_capabilities,
rar5_has_encrypted_entries);
if(ret != ARCHIVE_OK) {
(void) rar5_cleanup(ar);
}
return ret;
}