lzma_block_header_size(lzma_block *block) { if (block->version != 0) return LZMA_OPTIONS_ERROR; // Block Header Size + Block Flags + CRC32. uint32_t size = 1 + 1 + 4; // Compressed Size if (block->compressed_size != LZMA_VLI_UNKNOWN) { const uint32_t add = lzma_vli_size(block->compressed_size); if (add == 0 || block->compressed_size == 0) return LZMA_PROG_ERROR; size += add; } // Uncompressed Size if (block->uncompressed_size != LZMA_VLI_UNKNOWN) { const uint32_t add = lzma_vli_size(block->uncompressed_size); if (add == 0) return LZMA_PROG_ERROR; size += add; } // List of Filter Flags if (block->filters == NULL || block->filters[0].id == LZMA_VLI_UNKNOWN) return LZMA_PROG_ERROR; for (size_t i = 0; block->filters[i].id != LZMA_VLI_UNKNOWN; ++i) { // Don't allow too many filters. if (i == LZMA_FILTERS_MAX) return LZMA_PROG_ERROR; uint32_t add; return_if_error(lzma_filter_flags_size(&add, block->filters + i)); size += add; } // Pad to a multiple of four bytes. block->header_size = (size + 3) & ~UINT32_C(3); // NOTE: We don't verify that the encoded size of the Block stays // within limits. This is because it is possible that we are called // with exaggerated Compressed Size (e.g. LZMA_VLI_MAX) to reserve // space for Block Header, and later called again with lower, // real values. return LZMA_OK; }
lzma_index_append(lzma_index *i, lzma_allocator *allocator, lzma_vli unpadded_size, lzma_vli uncompressed_size) { if (unpadded_size < UNPADDED_SIZE_MIN || unpadded_size > UNPADDED_SIZE_MAX || uncompressed_size > LZMA_VLI_MAX) return LZMA_PROG_ERROR; // This looks a bit ugly. We want to first validate that the Index // and Stream stay in valid limits after adding this Record. After // validating, we may need to allocate a new lzma_index_group (it's // slightly more correct to validate before allocating, YMMV). lzma_ret ret; // First update the overall info so we can validate it. const lzma_vli index_list_size_add = lzma_vli_size(unpadded_size) + lzma_vli_size(uncompressed_size); const lzma_vli total_size = vli_ceil4(unpadded_size); i->total_size += total_size; i->uncompressed_size += uncompressed_size; ++i->count; i->index_list_size += index_list_size_add; if (i->total_size > LZMA_VLI_MAX || i->uncompressed_size > LZMA_VLI_MAX || lzma_index_size(i) > LZMA_BACKWARD_SIZE_MAX || lzma_index_file_size(i) > LZMA_VLI_MAX) ret = LZMA_DATA_ERROR; // Would grow past the limits. else ret = index_append_real(i, allocator, unpadded_size, uncompressed_size, false); if (ret != LZMA_OK) { // Something went wrong. Undo the updates. i->total_size -= total_size; i->uncompressed_size -= uncompressed_size; --i->count; i->index_list_size -= index_list_size_add; } return ret; }
lzma_index_append(lzma_index *i, const lzma_allocator *allocator, lzma_vli unpadded_size, lzma_vli uncompressed_size) { // Validate. if (i == NULL || unpadded_size < UNPADDED_SIZE_MIN || unpadded_size > UNPADDED_SIZE_MAX || uncompressed_size > LZMA_VLI_MAX) return LZMA_PROG_ERROR; index_stream *s = (index_stream *)(i->streams.rightmost); index_group *g = (index_group *)(s->groups.rightmost); const lzma_vli compressed_base = g == NULL ? 0 : vli_ceil4(g->records[g->last].unpadded_sum); const lzma_vli uncompressed_base = g == NULL ? 0 : g->records[g->last].uncompressed_sum; const uint32_t index_list_size_add = lzma_vli_size(unpadded_size) + lzma_vli_size(uncompressed_size); // Check that the file size will stay within limits. if (index_file_size(s->node.compressed_base, compressed_base + unpadded_size, s->record_count + 1, s->index_list_size + index_list_size_add, s->stream_padding) == LZMA_VLI_UNKNOWN) return LZMA_DATA_ERROR; // The size of the Index field must not exceed the maximum value // that can be stored in the Backward Size field. if (index_size(i->record_count + 1, i->index_list_size + index_list_size_add) > LZMA_BACKWARD_SIZE_MAX) return LZMA_DATA_ERROR; if (g != NULL && g->last + 1 < g->allocated) { // There is space in the last group at least for one Record. ++g->last; } else { // We need to allocate a new group. g = lzma_alloc(sizeof(index_group) + i->prealloc * sizeof(index_record), allocator); if (g == NULL) return LZMA_MEM_ERROR; g->last = 0; g->allocated = i->prealloc; // Reset prealloc so that if the application happens to // add new Records, the allocation size will be sane. i->prealloc = INDEX_GROUP_SIZE; // Set the start offsets of this group. g->node.uncompressed_base = uncompressed_base; g->node.compressed_base = compressed_base; g->number_base = s->record_count + 1; // Add the new group to the Stream. index_tree_append(&s->groups, &g->node); } // Add the new Record to the group. g->records[g->last].uncompressed_sum = uncompressed_base + uncompressed_size; g->records[g->last].unpadded_sum = compressed_base + unpadded_size; // Update the totals. ++s->record_count; s->index_list_size += index_list_size_add; i->total_size += vli_ceil4(unpadded_size); i->uncompressed_size += uncompressed_size; ++i->record_count; i->index_list_size += index_list_size_add; return LZMA_OK; }