1 /////////////////////////////////////////////////////////////////////////////// 2 // 3 /// \file block_header.c 4 /// \brief Utility functions to handle lzma_block 5 // 6 // Author: Lasse Collin 7 // 8 // This file has been put into the public domain. 9 // You can do whatever you want with this file. 10 // 11 /////////////////////////////////////////////////////////////////////////////// 12 13 #include "common.h" 14 #include "index.h" 15 16 17 extern LZMA_API(lzma_ret) 18 lzma_block_compressed_size(lzma_block *block, lzma_vli unpadded_size) 19 { 20 // Validate everything but Uncompressed Size and filters. 21 if (lzma_block_unpadded_size(block) == 0) 22 return LZMA_PROG_ERROR; 23 24 const uint32_t container_size = block->header_size 25 + lzma_check_size(block->check); 26 27 // Validate that Compressed Size will be greater than zero. 28 if (unpadded_size <= container_size) 29 return LZMA_DATA_ERROR; 30 31 // Calculate what Compressed Size is supposed to be. 32 // If Compressed Size was present in Block Header, 33 // compare that the new value matches it. 34 const lzma_vli compressed_size = unpadded_size - container_size; 35 if (block->compressed_size != LZMA_VLI_UNKNOWN 36 && block->compressed_size != compressed_size) 37 return LZMA_DATA_ERROR; 38 39 block->compressed_size = compressed_size; 40 41 return LZMA_OK; 42 } 43 44 45 extern LZMA_API(lzma_vli) 46 lzma_block_unpadded_size(const lzma_block *block) 47 { 48 // Validate the values that we are interested in i.e. all but 49 // Uncompressed Size and the filters. 50 // 51 // NOTE: This function is used for validation too, so it is 52 // essential that these checks are always done even if 53 // Compressed Size is unknown. 54 if (block == NULL || block->version > 1 55 || block->header_size < LZMA_BLOCK_HEADER_SIZE_MIN 56 || block->header_size > LZMA_BLOCK_HEADER_SIZE_MAX 57 || (block->header_size & 3) 58 || !lzma_vli_is_valid(block->compressed_size) 59 || block->compressed_size == 0 60 || (unsigned int)(block->check) > LZMA_CHECK_ID_MAX) 61 return 0; 62 63 // If Compressed Size is unknown, return that we cannot know 64 // size of the Block either. 65 if (block->compressed_size == LZMA_VLI_UNKNOWN) 66 return LZMA_VLI_UNKNOWN; 67 68 // Calculate Unpadded Size and validate it. 69 const lzma_vli unpadded_size = block->compressed_size 70 + block->header_size 71 + lzma_check_size(block->check); 72 73 assert(unpadded_size >= UNPADDED_SIZE_MIN); 74 if (unpadded_size > UNPADDED_SIZE_MAX) 75 return 0; 76 77 return unpadded_size; 78 } 79 80 81 extern LZMA_API(lzma_vli) 82 lzma_block_total_size(const lzma_block *block) 83 { 84 lzma_vli unpadded_size = lzma_block_unpadded_size(block); 85 86 if (unpadded_size != LZMA_VLI_UNKNOWN) 87 unpadded_size = vli_ceil4(unpadded_size); 88 89 return unpadded_size; 90 } 91