///////////////////////////////////////////////////////////////////////////////
#include "block_encoder.h"
-#include "block_private.h"
#include "filter_encoder.h"
#include "check.h"
+/// The maximum size of a single Block is limited by the maximum size of
+/// a Stream, which is 2^63 - 1 bytes (i.e. LZMA_VLI_VALUE_MAX). We could
+/// take into account the headers etc. to determine the exact maximum size
+/// of the Compressed Data field, but the complexity would give us nothing
+/// useful. Instead, limit the size of Compressed Data so that even with
+/// biggest possible Block Header and Check fields the total size of the
+/// Block stays as valid VLI. This way we don't produce incorrect output
+/// if someone will really try creating a Block of 8 EiB.
+///
+/// ~LZMA_VLI_C(3) is to guarantee that if we need padding at the end of
+/// the Compressed Data field, it will still stay in the proper limit.
+#define COMPRESSED_SIZE_MAX ((LZMA_VLI_VALUE_MAX - LZMA_BLOCK_HEADER_SIZE_MAX \
+ - LZMA_CHECK_SIZE_MAX) & ~LZMA_VLI_C(3))
+
+
struct lzma_coder_s {
/// The filters in the chain; initialized with lzma_raw_decoder_init().
lzma_next_coder next;
size_t *restrict out_pos, size_t out_size, lzma_action action)
{
// Check that our amount of input stays in proper limits.
- if (coder->options->uncompressed_size != LZMA_VLI_VALUE_UNKNOWN) {
- if (action == LZMA_FINISH) {
- if (coder->options->uncompressed_size
- - coder->uncompressed_size
- != (lzma_vli)(in_size - *in_pos))
- return LZMA_PROG_ERROR;
- } else {
- if (coder->options->uncompressed_size
- - coder->uncompressed_size
- < (lzma_vli)(in_size - *in_pos))
- return LZMA_PROG_ERROR;
- }
- } else if (LZMA_VLI_VALUE_MAX - coder->uncompressed_size
- < (lzma_vli)(in_size - *in_pos)) {
+ if (LZMA_VLI_VALUE_MAX - coder->uncompressed_size < in_size - *in_pos)
return LZMA_PROG_ERROR;
- }
- // Main loop
- while (*out_pos < out_size
- && (*in_pos < in_size || action != LZMA_RUN))
switch (coder->sequence) {
case SEQ_CODE: {
const size_t in_start = *in_pos;
const size_t in_used = *in_pos - in_start;
const size_t out_used = *out_pos - out_start;
- // FIXME We must also check that Total Size doesn't get
- // too big.
- if (update_size(&coder->compressed_size, out_used,
- coder->options->compressed_size))
+ if (COMPRESSED_SIZE_MAX - coder->compressed_size < out_used)
return LZMA_DATA_ERROR;
+ coder->compressed_size += out_used;
+
// No need to check for overflow because we have already
// checked it at the beginning of this function.
coder->uncompressed_size += in_used;
return ret;
assert(*in_pos == in_size);
+ assert(action == LZMA_FINISH);
+
coder->sequence = SEQ_PADDING;
- break;
}
+ // Fall through
+
case SEQ_PADDING:
// Pad Compressed Data to a multiple of four bytes.
- if (coder->compressed_size & 3) {
+ while (coder->compressed_size & 3) {
+ if (*out_pos >= out_size)
+ return LZMA_OK;
+
out[*out_pos] = 0x00;
++*out_pos;
- if (update_size(&coder->compressed_size, 1,
- coder->options->compressed_size))
- return LZMA_DATA_ERROR;
-
- break;
+ // No need to use check for overflow here since we
+ // have already checked in SEQ_CODE that Compressed
+ // Size will stay in proper limits.
+ ++coder->compressed_size;
}
- // Compressed and Uncompressed Sizes are now at their final
- // values. Verify that they match the values given to us.
- if (!is_size_valid(coder->compressed_size,
- coder->options->compressed_size)
- || !is_size_valid(coder->uncompressed_size,
- coder->options->uncompressed_size))
- return LZMA_DATA_ERROR;
-
// Copy the values into coder->options. The caller
// may use this information to construct Index.
coder->options->compressed_size = coder->compressed_size;
// Fall through
- case SEQ_CHECK:
- out[*out_pos] = coder->check.buffer.u8[coder->check_pos];
- ++*out_pos;
+ case SEQ_CHECK: {
+ const uint32_t check_size
+ = lzma_check_size(coder->options->check);
- if (++coder->check_pos
- == lzma_check_size(coder->options->check))
- return LZMA_STREAM_END;
+ while (*out_pos < out_size) {
+ out[*out_pos] = coder->check.buffer.u8[
+ coder->check_pos];
+ ++*out_pos;
- break;
+ if (++coder->check_pos == check_size)
+ return LZMA_STREAM_END;
+ }
- default:
- return LZMA_PROG_ERROR;
+ return LZMA_OK;
+ }
}
- return LZMA_OK;
+ return LZMA_PROG_ERROR;
}
+++ /dev/null
-///////////////////////////////////////////////////////////////////////////////
-//
-/// \file block_private.h
-/// \brief Common stuff for Block encoder and decoder
-//
-// Copyright (C) 2007 Lasse Collin
-//
-// This library is free software; you can redistribute it and/or
-// modify it under the terms of the GNU Lesser General Public
-// License as published by the Free Software Foundation; either
-// version 2.1 of the License, or (at your option) any later version.
-//
-// This library is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-// Lesser General Public License for more details.
-//
-///////////////////////////////////////////////////////////////////////////////
-
-#ifndef LZMA_BLOCK_COMMON_H
-#define LZMA_BLOCK_COMMON_H
-
-#include "common.h"
-
-
-static inline bool
-update_size(lzma_vli *size, lzma_vli add, lzma_vli limit)
-{
- if (limit > LZMA_VLI_VALUE_MAX)
- limit = LZMA_VLI_VALUE_MAX;
-
- if (limit < *size || limit - *size < add)
- return true;
-
- *size += add;
-
- return false;
-}
-
-
-static inline bool
-is_size_valid(lzma_vli size, lzma_vli reference)
-{
- return reference == LZMA_VLI_VALUE_UNKNOWN || reference == size;
-}
-
-#endif
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