--- /dev/null
+/*-
+* Copyright (c) 2018 Grzegorz Antoniak
+* 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"
+
+#ifdef HAVE_ERRNO_H
+#include <errno.h>
+#endif
+#include <time.h>
+#ifdef HAVE_ZLIB_H
+#include <zlib.h> /* crc32 */
+#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"
+#include "archive_blake2.h"
+
+/*#define CHECK_CRC_ON_SOLID_SKIP*/
+/*#define DONT_FAIL_ON_CRC_ERROR*/
+/*#define DEBUG*/
+
+#if __GNUC__ > 4 && !defined __OpenBSD__
+#define fallthrough __attribute__((fallthrough))
+#define unused __attribute__((unused))
+#else
+#define fallthrough
+#define unused
+#endif
+
+#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)
+#else
+#define DEBUG_CODE if(0)
+#endif
+
+/* Real RAR5 magic number is:
+ *
+ * 0x52, 0x61, 0x72, 0x21, 0x1a, 0x07, 0x01, 0x00
+ * "Rar!→•☺·\x00"
+ *
+ * It's stored in `rar5_signature` after 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. */
+
+unsigned char rar5_signature[] = { 243, 192, 211, 128, 187, 166, 160, 161 };
+const ssize_t rar5_signature_size = sizeof(rar5_signature);
+const size_t g_unpack_buf_chunk_size = 1024;
+const size_t g_unpack_window_size = 0x20000;
+
+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? */
+
+ /* 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;
+};
+
+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;
+
+ 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; /* Convinience 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 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. */
+struct compressed_block_header {
+ union {
+ struct {
+ uint8_t bit_size : 3;
+ uint8_t byte_count : 3;
+ uint8_t is_last_block : 1;
+ uint8_t is_table_present : 1;
+ } block_flags;
+ 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;
+
+ 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 {
+ 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 1 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;
+
+ /* An offset to QuickOpen list. This is not supported by this unpacker,
+ * becuase 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 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 cicrular 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;
+}
+
+/* Convinience function to cast filter_info** to void **. */
+static void** cdeque_filter_p(struct filter_info** f) {
+ return (void**) (size_t) f;
+}
+
+/* Convinience 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. Dellocates 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 struct rar5* get_context(struct archive_read* a) {
+ return (struct rar5*) a->format->data;
+}
+
+// TODO: make sure these functions return a little endian number
+
+/* Convinience functions used by filter implementations. */
+
+static uint32_t read_filter_data(struct rar5* rar, uint32_t offset) {
+ uint32_t* dptr = (uint32_t*) &rar->cstate.window_buf[offset];
+ // TODO: bswap if big endian
+ return *dptr;
+}
+
+static void write_filter_data(struct rar5* rar, uint32_t offset,
+ uint32_t value)
+{
+ uint32_t* dptr = (uint32_t*) &rar->cstate.filtered_buf[offset];
+ // TODO: bswap if big endian
+ *dptr = value;
+}
+
+static void circular_memcpy(uint8_t* dst, uint8_t* window, const int 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));
+ }
+}
+
+/* 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, (rar->cstate.solid_offset +
+ flt->block_start + i) & rar->cstate.window_mask);
+
+ if(addr & 0x80000000) {
+ if(((addr + offset) & 0x80000000) == 0) {
+ write_filter_data(rar, i, addr + file_size);
+ }
+ } else {
+ if((addr - file_size) & 0x80000000) {
+ uint32_t naddr = addr - offset;
+ write_filter_data(rar, 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;
+ const int mask = rar->cstate.window_mask;
+
+ 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) & mask];
+
+ if(b[3] == 0xEB) {
+ /* 0xEB = ARM's BL (branch + link) instruction. */
+ offset = read_filter_data(rar, (rar->cstate.solid_offset +
+ flt->block_start + i) & mask) & 0x00ffffff;
+
+ offset -= (uint32_t) ((i + flt->block_start) / 4);
+ offset = (offset & 0x00ffffff) | 0xeb000000;
+ write_filter_data(rar, 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);
+
+ if(rar->cstate.filtered_buf)
+ 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%02x", 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 int 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;
+ }
+}
+
+/* Convinience 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 index) {
+ int* q = rar->cstate.dist_cache;
+ int i, dist = q[index];
+
+ for(i = index; 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 successfull. 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)) && f != NULL)
+ 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;
+
+ 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)
+{
+ if(!ptr)
+ return 0;
+
+ ssize_t avail = -1;
+ *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 & 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
+ * the consuming process itself. */
+ 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
+ * autmatically. */
+ 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;
+
+ 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 rar5* rar, const uint8_t* p, uint32_t* value) {
+ uint32_t bits = 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 rar5* rar, const uint8_t* p, uint16_t* value) {
+ int bits = (int) 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 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(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 = *(const uint32_t*)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 = *(const uint64_t*)p;
+
+ return ARCHIVE_OK == consume(a, 8) ? 1 : 0;
+}
+
+static int bid_standard(struct archive_read* a) {
+ const uint8_t* p;
+
+ if(!read_ahead(a, rar5_signature_size, &p))
+ return -1;
+
+ if(!memcmp(rar5_signature, p, rar5_signature_size))
+ 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;
+
+ return ARCHIVE_FATAL;
+}
+
+static void init_header(struct archive_read* a) {
+ a->archive.archive_format = ARCHIVE_FORMAT_RAR_V5;
+ a->archive.archive_format_name = "RAR5";
+}
+
+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;
+
+ if(!read_var(a, &locator_flags, NULL)) {
+ return ARCHIVE_EOF;
+ }
+
+ enum LOCATOR_FLAGS {
+ QLIST = 0x01, RECOVERY = 0x02,
+ };
+
+ 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;
+ size_t value_len;
+
+ 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;
+ }
+
+ enum HASH_TYPE {
+ BLAKE2sp = 0x00
+ };
+
+ /* 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%02x)", (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_htime(struct archive_read* a,
+ struct archive_entry* e, struct rar5* rar,
+ ssize_t* extra_data_size)
+{
+ char unix_time = 0;
+ size_t flags;
+ 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 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;
+ int ret = ARCHIVE_FATAL;
+ size_t var_size;
+
+ enum EXTRA {
+ CRYPT = 0x01, HASH = 0x02, HTIME = 0x03, VERSION_ = 0x04,
+ REDIR = 0x05, UOWNER = 0x06, SUBDATA = 0x07
+ };
+
+ 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 HASH:
+ ret = parse_file_extra_hash(a, rar, &extra_data_size);
+ break;
+ case HTIME:
+ ret = parse_file_extra_htime(a, e, rar, &extra_data_size);
+ break;
+ case CRYPT:
+ fallthrough;
+ case VERSION_:
+ fallthrough;
+ case REDIR:
+ fallthrough;
+ case UOWNER:
+ fallthrough;
+ case SUBDATA:
+ fallthrough;
+ default:
+ archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
+ "Unknown extra field in file/service block: 0x%02x",
+ (int) extra_field_id);
+ return ARCHIVE_FATAL;
+ }
+ }
+
+ 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, file_flags, file_attr, compression_info, host_os,
+ name_size;
+ uint64_t unpacked_size;
+ uint32_t mtime = 0, crc;
+ int c_method = 0, c_version = 0, is_dir;
+ char name_utf8_buf[2048 * 4];
+ const uint8_t* p;
+
+ memset(entry, 0, sizeof(struct archive_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;
+ 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;
+ }
+
+ enum FILE_FLAGS {
+ DIRECTORY = 0x0001, UTIME = 0x0002, CRC32 = 0x0004,
+ UNKNOWN_UNPACKED_SIZE = 0x0008,
+ };
+
+ enum COMP_INFO_FLAGS {
+ SOLID = 0x0040,
+ };
+
+ 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;
+ }
+
+ is_dir = (int) (file_flags & DIRECTORY);
+
+ 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);
+
+ rar->cstate.window_size = is_dir ?
+ 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;
+
+ if(!read_var_sized(a, &host_os, NULL))
+ return ARCHIVE_EOF;
+
+ enum HOST_OS {
+ HOST_WINDOWS = 0,
+ HOST_UNIX = 1,
+ };
+
+ if(host_os == HOST_WINDOWS) {
+ /* Host OS is Windows */
+
+ unsigned short mode = 0660;
+
+ if(is_dir)
+ mode |= AE_IFDIR;
+ else
+ mode |= AE_IFREG;
+
+ archive_entry_set_mode(entry, mode);
+ } else if(host_os == HOST_UNIX) {
+ /* Host OS is Unix */
+ archive_entry_set_mode(entry, (unsigned short) file_attr);
+ } else {
+ /* Unknown host OS */
+ archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
+ "Unsupported Host OS: 0x%02x", (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 > 2047) {
+ 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;
+ }
+
+ if(extra_data_size > 0) {
+ int ret = process_head_file_extra(a, entry, rar, extra_data_size);
+
+ /* Sanity check. */
+ 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;
+ 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;
+ }
+
+ archive_entry_update_pathname_utf8(entry, name_utf8_buf);
+
+ 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;
+ }
+
+ 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;
+
+ /* But skip the data part automatically. It's no use for the user anyway.
+ * It contains only service data needed to properly unpack the archive. */
+ 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)
+{
+ (void) entry;
+
+ int ret;
+ size_t extra_data_size,
+ extra_field_size,
+ extra_field_id,
+ archive_flags;
+
+ 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;
+ }
+
+ enum MAIN_FLAGS {
+ VOLUME = 0x0001, /* multi-volume archive */
+ VOLUME_NUMBER = 0x0002, /* volume number, first vol doesnt have it */
+ SOLID = 0x0004, /* solid archive */
+ PROTECT = 0x0008, /* contains Recovery info */
+ LOCK = 0x0010, /* readonly flag, not used */
+ };
+
+ rar->main.volume = (archive_flags & VOLUME) > 0;
+ rar->main.solid = (archive_flags & SOLID) > 0;
+
+ if(archive_flags & VOLUME_NUMBER) {
+ size_t v;
+ if(!read_var_sized(a, &v, NULL)) {
+ return ARCHIVE_EOF;
+ }
+
+ rar->main.vol_no = (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;
+ }
+
+ enum MAIN_EXTRA {
+ // Just one attribute here.
+ LOCATOR = 0x01,
+ };
+
+ 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%02x)", (int) extra_field_id);
+ return ARCHIVE_FATAL;
+ }
+
+ return ARCHIVE_OK;
+}
+
+static int scan_for_signature(struct archive_read* a);
+
+static int process_base_block(struct archive_read* a,
+ struct archive_entry* entry)
+{
+ struct rar5* rar = get_context(a);
+ uint32_t hdr_crc, computed_crc;
+ size_t raw_hdr_size, hdr_size_len, hdr_size;
+ size_t header_id, header_flags;
+ const uint8_t* p;
+ int 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;
+ }
+
+ /* Sanity check, maximum header size for RAR5 is 2MB. */
+ if(raw_hdr_size > (2 * 1024 * 1024)) {
+ archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
+ "Base block header is too large");
+
+ return ARCHIVE_FATAL;
+ }
+
+ hdr_size = raw_hdr_size + hdr_size_len;
+
+ /* Read the whole header data into memory. */
+ 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 = hdr_size;
+ rar->generic.last_header_id = header_id;
+ rar->main.endarc = 0;
+
+ /* Those are possible header ids in RARv5. */
+ enum HEADER_TYPE {
+ HEAD_MARK = 0x00, HEAD_MAIN = 0x01, HEAD_FILE = 0x02,
+ HEAD_SERVICE = 0x03, HEAD_CRYPT = 0x04, HEAD_ENDARC = 0x05,
+ HEAD_UNKNOWN = 0xff,
+ };
+
+ 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;
+
+ if(rar->main.volume) {
+ ret = scan_for_signature(a);
+
+ rar->vol.expected_vol_no = rar->main.vol_no + 1;
+
+ if(ret == ARCHIVE_FATAL) {
+ return ARCHIVE_EOF;
+ } else {
+ 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);
+
+ struct archive_entry entry;
+ ret = process_base_block(a, &entry);
+
+ 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, rar5_signature_size)) {
+ 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;
+ rar->cstate.window_mask = rar->cstate.window_size - 1;
+
+ if(rar->cstate.window_buf)
+ free(rar->cstate.window_buf);
+
+ if(rar->cstate.filtered_buf)
+ free(rar->cstate.filtered_buf);
+
+ rar->cstate.window_buf = calloc(1, rar->cstate.window_size);
+ rar->cstate.filtered_buf = calloc(1, rar->cstate.window_size);
+
+ 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 = 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] + 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;
+ uint16_t bitfield;
+ uint32_t pos;
+ struct rar5* rar = get_context(a);
+
+ if(ARCHIVE_OK != read_bits_16(rar, p, &bitfield)) {
+ return ARCHIVE_EOF;
+ }
+
+ 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 are 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;) {
+ 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; 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++;
+ continue;
+ }
+
+ if(num < 18) {
+ /* 16..17: repeat previous code */
+ uint16_t n;
+ if(ARCHIVE_OK != read_bits_16(rar, p, &n))
+ return ARCHIVE_EOF;
+
+ 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;
+ }
+
+ continue;
+ }
+
+ /* other codes: fill with zeroes `n` times */
+ uint16_t n;
+ if(ARCHIVE_OK != read_bits_16(rar, p, &n))
+ return ARCHIVE_EOF;
+
+ 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)
+{
+ memcpy(hdr, p, sizeof(struct compressed_block_header));
+
+ if(hdr->block_flags.byte_count > 2) {
+ archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
+ "Unsupported block header size (was %d, max is 2)",
+ hdr->block_flags.byte_count);
+ return ARCHIVE_FATAL;
+ }
+
+ /* This should probably use bit reader interface in order to be more
+ * future-proof. */
+ *block_size = 0;
+ switch(hdr->block_flags.byte_count) {
+ /* 1-byte block size */
+ case 0:
+ *block_size = *(const uint8_t*) &p[2];
+ break;
+
+ /* 2-byte block size */
+ case 1:
+ *block_size = *(const uint16_t*) &p[2];
+ break;
+
+ /* 3-byte block size */
+ case 2:
+ *block_size = *(const uint32_t*) &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. */
+ uint8_t 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%02x, expected 0x%02x",
+ hdr->block_cksum, calculated_cksum);
+
+ return ARCHIVE_FATAL;
+ }
+
+ return ARCHIVE_OK;
+}
+
+/* Convinience function used during filter processing. */
+static int parse_filter_data(struct rar5* rar, const uint8_t* p,
+ uint32_t* filter_data)
+{
+ int i, bytes;
+ uint32_t data = 0;
+
+ if(ARCHIVE_OK != read_consume_bits(rar, p, 2, &bytes))
+ return ARCHIVE_EOF;
+
+ bytes++;
+
+ for(i = 0; i < bytes; i++) {
+ uint16_t byte;
+
+ if(ARCHIVE_OK != read_bits_16(rar, p, &byte)) {
+ return ARCHIVE_EOF;
+ }
+
+ data += (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 rar5* rar = get_context(ar);
+
+ /* Read the parameters from the input stream. */
+ if(ARCHIVE_OK != parse_filter_data(rar, p, &block_start))
+ return ARCHIVE_EOF;
+
+ if(ARCHIVE_OK != parse_filter_data(rar, p, &block_length))
+ return ARCHIVE_EOF;
+
+ if(ARCHIVE_OK != read_bits_16(rar, p, &filter_type))
+ return ARCHIVE_EOF;
+
+ 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. */
+ struct filter_info* 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 != read_consume_bits(rar, p, 5, &channels))
+ return ARCHIVE_EOF;
+
+ filt->channels = channels + 1;
+ }
+
+ return ARCHIVE_OK;
+}
+
+static int decode_code_length(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(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 int cmask = rar->cstate.window_mask;
+ const int64_t write_ptr = rar->cstate.write_ptr + rar->cstate.solid_offset;
+ int i;
+
+ /* 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 int cmask = rar->cstate.window_mask;
+ const struct compressed_block_header* hdr = &rar->last_block_hdr;
+ const uint8_t bit_size = 1 + hdr->block_flags.bit_size;
+
+ 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 '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 transform
+ * 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(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;
+ dist += (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 != read_bits_32(rar, p, &add)) {
+ /* Return EOF if we can't read more data. */
+ return ARCHIVE_EOF;
+ }
+
+ 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;
+ }
+
+ dist += low_dist;
+ } else {
+ /* dbits is one of [0,1,2,3] */
+ int add;
+
+ if(ARCHIVE_OK != read_consume_bits(rar, p, dbits, &add)) {
+ /* Return EOF if we can't read more data. */
+ return ARCHIVE_EOF;
+ }
+
+ 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 if(num < 262) {
+ const int index = num - 258;
+ const int dist = dist_cache_touch(rar, index);
+
+ 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(rar, p, len_slot);
+ rar->cstate.last_len = len;
+
+ if(ARCHIVE_OK != copy_string(a, len, dist))
+ return ARCHIVE_FATAL;
+
+ continue;
+ }
+
+ /* The program counter shouldn't reach here. */
+ archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
+ "Unsupported block code: 0x%02x", num);
+
+ return ARCHIVE_FATAL;
+ }
+
+ 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;
+
+ /* 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. */
+
+ while(1) {
+ if(!read_ahead(a, chunk_size, &p))
+ return ARCHIVE_EOF;
+
+ for(i = 0; i < chunk_size - rar5_signature_size; i++) {
+ if(memcmp(&p[i], rar5_signature, rar5_signature_size) == 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 + rar5_signature_size);
+ 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) {
+ rar->main.endarc = 0;
+ while(ARCHIVE_RETRY == skip_base_block(a));
+ break;
+ } else {
+ /* Skip current base block. In order to properly skip it,
+ * we weally need to simply parse it and discard the results. */
+
+ lret = skip_base_block(a);
+
+ /* 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;
+
+ /* 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);
+
+ rar->vol.push_buf = malloc(block_size);
+ if(!rar->vol.push_buf) {
+ archive_set_error(&a->archive, ENOMEM, "Can't allocate memory for a "
+ "merge block buffer.");
+ return ARCHIVE_FATAL;
+ }
+
+ /* 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(!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) {
+ ret = advance_multivolume(a);
+ 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;
+
+ rar->cstate.block_parsing_finished = 0;
+
+ /* 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. */
+ ssize_t to_skip = sizeof(struct compressed_block_header) +
+ rar->last_block_hdr.block_flags.byte_count + 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. */
+
+ ssize_t 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->bits.in_addr = 0;
+ rar->bits.bit_addr = 0;
+
+ if(rar->last_block_hdr.block_flags.is_table_present) {
+ /* Load Huffman tables. */
+ ret = parse_tables(a, rar, p);
+ if(ret != ARCHIVE_OK) {
+ /* Error during decompression of Huffman tables. */
+ return ret;
+ }
+ }
+ } else {
+ 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;
+
+ /* 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;
+}
+
+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;
+ }
+
+ 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)
+{
+ 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;
+ }
+ }
+
+ size_t to_read = rar5_min(rar->file.bytes_remaining, 64 * 1024);
+
+ 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_write_ptr;
+
+ rar->file.bytes_remaining -= to_read;
+ rar->cstate.last_write_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
+ };
+
+ 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%08x",
+ 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 checkums 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: %08x, expected: %08x)\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 (%08x/%08x)\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) {
+ DEBUG_CODE {
+ printf("Checksum error: BLAKE2sp (%08x/%08x)\n",
+ *(uint32_t*)rar->file.blake2sp,
+ *(uint32_t*)b2_buf);
+ }
+
+#ifndef DONT_FAIL_ON_CRC_ERROR
+ archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
+ "Checksum error: BLAKE2");
+
+ return ARCHIVE_FATAL;
+#endif
+ } else {
+ DEBUG_CODE {
+ printf("Checksum OK: BLAKE2sp (%08x/%08x)\n",
+ *(uint32_t*)rar->file.blake2sp,
+ *(uint32_t*)b2_buf);
+ }
+ }
+ }
+ }
+
+ /* Finalization for this file has been successfully completed. */
+ return ARCHIVE_OK;
+}
+
+static int verify_global_checksums(struct archive_read* a) {
+ return verify_checksums(a);
+}
+
+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(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;
+
+ 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. */
+
+ 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. */
+ rar->skip_mode = 1;
+
+ /* 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 = 0;
+
+ if(ret < 0) {
+ /* Propagate any potential error conditions to the caller. */
+ return ret;
+ }
+ }
+
+ return ARCHIVE_OK;
+ } 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);
+
+ if(rar->cstate.window_buf)
+ free(rar->cstate.window_buf);
+
+ if(rar->cstate.filtered_buf)
+ free(rar->cstate.filtered_buf);
+
+ if(rar->vol.push_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) {
+ ssize_t i;
+
+ memset(rar, 0, sizeof(struct rar5));
+
+ /* Decrypt the magic signature pattern. Check the comment near the
+ * `rar5_signature` symbol to read the rationale behind this. */
+
+ if(rar5_signature[0] == 243) {
+ for(i = 0; i < rar5_signature_size; i++) {
+ rar5_signature[i] ^= 0xA1;
+ }
+ }
+
+ 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");
+ 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;
+}
projects / thirdparty / libarchive.git / commitdiff
