10578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync/* 20578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * .xz Stream decoder 30578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * 40578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * Author: Lasse Collin <lasse.collin@tukaani.org> 50578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * 60578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * This file has been put into the public domain. 70578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * You can do whatever you want with this file. 80578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync */ 90578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 100578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync#include "xz_private.h" 110578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync#include "xz_stream.h" 120578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 130578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync#ifdef XZ_USE_CRC64 140578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync# define IS_CRC64(check_type) ((check_type) == XZ_CHECK_CRC64) 150578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync#else 160578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync# define IS_CRC64(check_type) false 170578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync#endif 180578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 190578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync/* Hash used to validate the Index field */ 200578287ba49f36d031f6d61bb53f5b54f56c65a3repo syncstruct xz_dec_hash { 210578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync vli_type unpadded; 220578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync vli_type uncompressed; 230578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync uint32_t crc32; 240578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync}; 250578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 260578287ba49f36d031f6d61bb53f5b54f56c65a3repo syncstruct xz_dec { 270578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* Position in dec_main() */ 280578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync enum { 290578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync SEQ_STREAM_HEADER, 300578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync SEQ_BLOCK_START, 310578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync SEQ_BLOCK_HEADER, 320578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync SEQ_BLOCK_UNCOMPRESS, 330578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync SEQ_BLOCK_PADDING, 340578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync SEQ_BLOCK_CHECK, 350578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync SEQ_INDEX, 360578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync SEQ_INDEX_PADDING, 370578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync SEQ_INDEX_CRC32, 380578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync SEQ_STREAM_FOOTER 390578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync } sequence; 400578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 410578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* Position in variable-length integers and Check fields */ 420578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync uint32_t pos; 430578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 440578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* Variable-length integer decoded by dec_vli() */ 450578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync vli_type vli; 460578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 470578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* Saved in_pos and out_pos */ 480578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync size_t in_start; 490578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync size_t out_start; 500578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 510578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync#ifdef XZ_USE_CRC64 520578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* CRC32 or CRC64 value in Block or CRC32 value in Index */ 530578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync uint64_t crc; 540578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync#else 550578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* CRC32 value in Block or Index */ 560578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync uint32_t crc; 570578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync#endif 580578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 590578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* Type of the integrity check calculated from uncompressed data */ 600578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync enum xz_check check_type; 610578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 620578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* Operation mode */ 630578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync enum xz_mode mode; 640578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 650578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* 660578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * True if the next call to xz_dec_run() is allowed to return 670578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * XZ_BUF_ERROR. 680578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync */ 690578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync bool allow_buf_error; 700578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 710578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* Information stored in Block Header */ 720578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync struct { 730578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* 740578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * Value stored in the Compressed Size field, or 750578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * VLI_UNKNOWN if Compressed Size is not present. 760578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync */ 770578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync vli_type compressed; 780578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 790578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* 800578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * Value stored in the Uncompressed Size field, or 810578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * VLI_UNKNOWN if Uncompressed Size is not present. 820578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync */ 830578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync vli_type uncompressed; 840578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 850578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* Size of the Block Header field */ 860578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync uint32_t size; 870578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync } block_header; 880578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 890578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* Information collected when decoding Blocks */ 900578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync struct { 910578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* Observed compressed size of the current Block */ 920578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync vli_type compressed; 930578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 940578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* Observed uncompressed size of the current Block */ 950578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync vli_type uncompressed; 960578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 970578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* Number of Blocks decoded so far */ 980578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync vli_type count; 990578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 1000578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* 1010578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * Hash calculated from the Block sizes. This is used to 1020578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * validate the Index field. 1030578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync */ 1040578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync struct xz_dec_hash hash; 1050578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync } block; 1060578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 1070578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* Variables needed when verifying the Index field */ 1080578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync struct { 1090578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* Position in dec_index() */ 1100578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync enum { 1110578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync SEQ_INDEX_COUNT, 1120578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync SEQ_INDEX_UNPADDED, 1130578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync SEQ_INDEX_UNCOMPRESSED 1140578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync } sequence; 1150578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 1160578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* Size of the Index in bytes */ 1170578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync vli_type size; 1180578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 1190578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* Number of Records (matches block.count in valid files) */ 1200578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync vli_type count; 1210578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 1220578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* 1230578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * Hash calculated from the Records (matches block.hash in 1240578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * valid files). 1250578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync */ 1260578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync struct xz_dec_hash hash; 1270578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync } index; 1280578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 1290578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* 1300578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * Temporary buffer needed to hold Stream Header, Block Header, 1310578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * and Stream Footer. The Block Header is the biggest (1 KiB) 1320578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * so we reserve space according to that. buf[] has to be aligned 1330578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * to a multiple of four bytes; the size_t variables before it 1340578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * should guarantee this. 1350578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync */ 1360578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync struct { 1370578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync size_t pos; 1380578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync size_t size; 1390578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync uint8_t buf[1024]; 1400578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync } temp; 1410578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 1420578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync struct xz_dec_lzma2 *lzma2; 1430578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 1440578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync#ifdef XZ_DEC_BCJ 1450578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync struct xz_dec_bcj *bcj; 1460578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync bool bcj_active; 1470578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync#endif 1480578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync}; 1490578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 1500578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync#ifdef XZ_DEC_ANY_CHECK 1510578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync/* Sizes of the Check field with different Check IDs */ 1520578287ba49f36d031f6d61bb53f5b54f56c65a3repo syncstatic const uint8_t check_sizes[16] = { 1530578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 0, 1540578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 4, 4, 4, 1550578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 8, 8, 8, 1560578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 16, 16, 16, 1570578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 32, 32, 32, 1580578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 64, 64, 64 1590578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync}; 1600578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync#endif 1610578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 1620578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync/* 1630578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * Fill s->temp by copying data starting from b->in[b->in_pos]. Caller 1640578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * must have set s->temp.pos to indicate how much data we are supposed 1650578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * to copy into s->temp.buf. Return true once s->temp.pos has reached 1660578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * s->temp.size. 1670578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync */ 1680578287ba49f36d031f6d61bb53f5b54f56c65a3repo syncstatic bool fill_temp(struct xz_dec *s, struct xz_buf *b) 1690578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync{ 1700578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync size_t copy_size = min_t(size_t, 1710578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync b->in_size - b->in_pos, s->temp.size - s->temp.pos); 1720578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 1730578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync memcpy(s->temp.buf + s->temp.pos, b->in + b->in_pos, copy_size); 1740578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync b->in_pos += copy_size; 1750578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->temp.pos += copy_size; 1760578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 1770578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (s->temp.pos == s->temp.size) { 1780578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->temp.pos = 0; 1790578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return true; 1800578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync } 1810578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 1820578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return false; 1830578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync} 1840578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 1850578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync/* Decode a variable-length integer (little-endian base-128 encoding) */ 1860578287ba49f36d031f6d61bb53f5b54f56c65a3repo syncstatic enum xz_ret dec_vli(struct xz_dec *s, const uint8_t *in, 1870578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync size_t *in_pos, size_t in_size) 1880578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync{ 1890578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync uint8_t byte; 1900578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 1910578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (s->pos == 0) 1920578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->vli = 0; 1930578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 1940578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync while (*in_pos < in_size) { 1950578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync byte = in[*in_pos]; 1960578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync ++*in_pos; 1970578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 1980578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->vli |= (vli_type)(byte & 0x7F) << s->pos; 1990578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 2000578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if ((byte & 0x80) == 0) { 2010578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* Don't allow non-minimal encodings. */ 2020578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (byte == 0 && s->pos != 0) 2030578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_DATA_ERROR; 2040578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 2050578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->pos = 0; 2060578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_STREAM_END; 2070578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync } 2080578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 2090578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->pos += 7; 2100578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (s->pos == 7 * VLI_BYTES_MAX) 2110578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_DATA_ERROR; 2120578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync } 2130578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 2140578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_OK; 2150578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync} 2160578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 2170578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync/* 2180578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * Decode the Compressed Data field from a Block. Update and validate 2190578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * the observed compressed and uncompressed sizes of the Block so that 2200578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * they don't exceed the values possibly stored in the Block Header 2210578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * (validation assumes that no integer overflow occurs, since vli_type 2220578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * is normally uint64_t). Update the CRC32 or CRC64 value if presence of 2230578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * the CRC32 or CRC64 field was indicated in Stream Header. 2240578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * 2250578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * Once the decoding is finished, validate that the observed sizes match 2260578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * the sizes possibly stored in the Block Header. Update the hash and 2270578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * Block count, which are later used to validate the Index field. 2280578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync */ 2290578287ba49f36d031f6d61bb53f5b54f56c65a3repo syncstatic enum xz_ret dec_block(struct xz_dec *s, struct xz_buf *b) 2300578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync{ 2310578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync enum xz_ret ret; 2320578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 2330578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->in_start = b->in_pos; 2340578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->out_start = b->out_pos; 2350578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 2360578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync#ifdef XZ_DEC_BCJ 2370578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (s->bcj_active) 2380578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync ret = xz_dec_bcj_run(s->bcj, s->lzma2, b); 2390578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync else 2400578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync#endif 2410578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync ret = xz_dec_lzma2_run(s->lzma2, b); 2420578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 2430578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->block.compressed += b->in_pos - s->in_start; 2440578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->block.uncompressed += b->out_pos - s->out_start; 2450578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 2460578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* 2470578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * There is no need to separately check for VLI_UNKNOWN, since 2480578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * the observed sizes are always smaller than VLI_UNKNOWN. 2490578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync */ 2500578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (s->block.compressed > s->block_header.compressed 2510578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync || s->block.uncompressed 2520578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync > s->block_header.uncompressed) 2530578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_DATA_ERROR; 2540578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 2550578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (s->check_type == XZ_CHECK_CRC32) 2560578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->crc = xz_crc32(b->out + s->out_start, 2570578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync b->out_pos - s->out_start, s->crc); 2580578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync#ifdef XZ_USE_CRC64 2590578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync else if (s->check_type == XZ_CHECK_CRC64) 2600578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->crc = xz_crc64(b->out + s->out_start, 2610578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync b->out_pos - s->out_start, s->crc); 2620578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync#endif 2630578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 2640578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (ret == XZ_STREAM_END) { 2650578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (s->block_header.compressed != VLI_UNKNOWN 2660578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync && s->block_header.compressed 2670578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync != s->block.compressed) 2680578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_DATA_ERROR; 2690578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 2700578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (s->block_header.uncompressed != VLI_UNKNOWN 2710578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync && s->block_header.uncompressed 2720578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync != s->block.uncompressed) 2730578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_DATA_ERROR; 2740578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 2750578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->block.hash.unpadded += s->block_header.size 2760578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync + s->block.compressed; 2770578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 2780578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync#ifdef XZ_DEC_ANY_CHECK 2790578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->block.hash.unpadded += check_sizes[s->check_type]; 2800578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync#else 2810578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (s->check_type == XZ_CHECK_CRC32) 2820578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->block.hash.unpadded += 4; 2830578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync else if (IS_CRC64(s->check_type)) 2840578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->block.hash.unpadded += 8; 2850578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync#endif 2860578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 2870578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->block.hash.uncompressed += s->block.uncompressed; 2880578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->block.hash.crc32 = xz_crc32( 2890578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync (const uint8_t *)&s->block.hash, 2900578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync sizeof(s->block.hash), s->block.hash.crc32); 2910578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 2920578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync ++s->block.count; 2930578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync } 2940578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 2950578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return ret; 2960578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync} 2970578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 2980578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync/* Update the Index size and the CRC32 value. */ 2990578287ba49f36d031f6d61bb53f5b54f56c65a3repo syncstatic void index_update(struct xz_dec *s, const struct xz_buf *b) 3000578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync{ 3010578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync size_t in_used = b->in_pos - s->in_start; 3020578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->index.size += in_used; 3030578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->crc = xz_crc32(b->in + s->in_start, in_used, s->crc); 3040578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync} 3050578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 3060578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync/* 3070578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * Decode the Number of Records, Unpadded Size, and Uncompressed Size 3080578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * fields from the Index field. That is, Index Padding and CRC32 are not 3090578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * decoded by this function. 3100578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * 3110578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * This can return XZ_OK (more input needed), XZ_STREAM_END (everything 3120578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * successfully decoded), or XZ_DATA_ERROR (input is corrupt). 3130578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync */ 3140578287ba49f36d031f6d61bb53f5b54f56c65a3repo syncstatic enum xz_ret dec_index(struct xz_dec *s, struct xz_buf *b) 3150578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync{ 3160578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync enum xz_ret ret; 3170578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 3180578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync do { 3190578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync ret = dec_vli(s, b->in, &b->in_pos, b->in_size); 3200578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (ret != XZ_STREAM_END) { 3210578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync index_update(s, b); 3220578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return ret; 3230578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync } 3240578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 3250578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync switch (s->index.sequence) { 3260578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync case SEQ_INDEX_COUNT: 3270578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->index.count = s->vli; 3280578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 3290578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* 3300578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * Validate that the Number of Records field 3310578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * indicates the same number of Records as 3320578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * there were Blocks in the Stream. 3330578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync */ 3340578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (s->index.count != s->block.count) 3350578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_DATA_ERROR; 3360578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 3370578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->index.sequence = SEQ_INDEX_UNPADDED; 3380578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync break; 3390578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 3400578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync case SEQ_INDEX_UNPADDED: 3410578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->index.hash.unpadded += s->vli; 3420578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->index.sequence = SEQ_INDEX_UNCOMPRESSED; 3430578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync break; 3440578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 3450578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync case SEQ_INDEX_UNCOMPRESSED: 3460578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->index.hash.uncompressed += s->vli; 3470578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->index.hash.crc32 = xz_crc32( 3480578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync (const uint8_t *)&s->index.hash, 3490578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync sizeof(s->index.hash), 3500578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->index.hash.crc32); 3510578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync --s->index.count; 3520578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->index.sequence = SEQ_INDEX_UNPADDED; 3530578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync break; 3540578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync } 3550578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync } while (s->index.count > 0); 3560578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 3570578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_STREAM_END; 3580578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync} 3590578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 3600578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync/* 3610578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * Validate that the next four or eight input bytes match the value 3620578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * of s->crc. s->pos must be zero when starting to validate the first byte. 3630578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * The "bits" argument allows using the same code for both CRC32 and CRC64. 3640578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync */ 3650578287ba49f36d031f6d61bb53f5b54f56c65a3repo syncstatic enum xz_ret crc_validate(struct xz_dec *s, struct xz_buf *b, 3660578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync uint32_t bits) 3670578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync{ 3680578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync do { 3690578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (b->in_pos == b->in_size) 3700578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_OK; 3710578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 3720578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (((s->crc >> s->pos) & 0xFF) != b->in[b->in_pos++]) 3730578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_DATA_ERROR; 3740578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 3750578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->pos += 8; 3760578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 3770578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync } while (s->pos < bits); 3780578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 3790578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->crc = 0; 3800578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->pos = 0; 3810578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 3820578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_STREAM_END; 3830578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync} 3840578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 3850578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync#ifdef XZ_DEC_ANY_CHECK 3860578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync/* 3870578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * Skip over the Check field when the Check ID is not supported. 3880578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * Returns true once the whole Check field has been skipped over. 3890578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync */ 3900578287ba49f36d031f6d61bb53f5b54f56c65a3repo syncstatic bool check_skip(struct xz_dec *s, struct xz_buf *b) 3910578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync{ 3920578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync while (s->pos < check_sizes[s->check_type]) { 3930578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (b->in_pos == b->in_size) 3940578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return false; 3950578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 3960578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync ++b->in_pos; 3970578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync ++s->pos; 3980578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync } 3990578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 4000578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->pos = 0; 4010578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 4020578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return true; 4030578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync} 4040578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync#endif 4050578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 4060578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync/* Decode the Stream Header field (the first 12 bytes of the .xz Stream). */ 4070578287ba49f36d031f6d61bb53f5b54f56c65a3repo syncstatic enum xz_ret dec_stream_header(struct xz_dec *s) 4080578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync{ 4090578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (!memeq(s->temp.buf, HEADER_MAGIC, HEADER_MAGIC_SIZE)) 4100578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_FORMAT_ERROR; 4110578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 4120578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (xz_crc32(s->temp.buf + HEADER_MAGIC_SIZE, 2, 0) 4130578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync != get_le32(s->temp.buf + HEADER_MAGIC_SIZE + 2)) 4140578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_DATA_ERROR; 4150578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 4160578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (s->temp.buf[HEADER_MAGIC_SIZE] != 0) 4170578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_OPTIONS_ERROR; 4180578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 4190578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* 4200578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * Of integrity checks, we support none (Check ID = 0), 4210578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * CRC32 (Check ID = 1), and optionally CRC64 (Check ID = 4). 4220578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * However, if XZ_DEC_ANY_CHECK is defined, we will accept other 4230578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * check types too, but then the check won't be verified and 4240578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * a warning (XZ_UNSUPPORTED_CHECK) will be given. 4250578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync */ 4260578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->check_type = s->temp.buf[HEADER_MAGIC_SIZE + 1]; 4270578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 4280578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync#ifdef XZ_DEC_ANY_CHECK 4290578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (s->check_type > XZ_CHECK_MAX) 4300578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_OPTIONS_ERROR; 4310578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 4320578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (s->check_type > XZ_CHECK_CRC32 && !IS_CRC64(s->check_type)) 4330578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_UNSUPPORTED_CHECK; 4340578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync#else 4350578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (s->check_type > XZ_CHECK_CRC32 && !IS_CRC64(s->check_type)) 4360578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_OPTIONS_ERROR; 4370578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync#endif 4380578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 4390578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_OK; 4400578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync} 4410578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 4420578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync/* Decode the Stream Footer field (the last 12 bytes of the .xz Stream) */ 4430578287ba49f36d031f6d61bb53f5b54f56c65a3repo syncstatic enum xz_ret dec_stream_footer(struct xz_dec *s) 4440578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync{ 4450578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (!memeq(s->temp.buf + 10, FOOTER_MAGIC, FOOTER_MAGIC_SIZE)) 4460578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_DATA_ERROR; 4470578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 4480578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (xz_crc32(s->temp.buf + 4, 6, 0) != get_le32(s->temp.buf)) 4490578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_DATA_ERROR; 4500578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 4510578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* 4520578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * Validate Backward Size. Note that we never added the size of the 4530578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * Index CRC32 field to s->index.size, thus we use s->index.size / 4 4540578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * instead of s->index.size / 4 - 1. 4550578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync */ 4560578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if ((s->index.size >> 2) != get_le32(s->temp.buf + 4)) 4570578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_DATA_ERROR; 4580578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 4590578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (s->temp.buf[8] != 0 || s->temp.buf[9] != s->check_type) 4600578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_DATA_ERROR; 4610578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 4620578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* 4630578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * Use XZ_STREAM_END instead of XZ_OK to be more convenient 4640578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * for the caller. 4650578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync */ 4660578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_STREAM_END; 4670578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync} 4680578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 4690578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync/* Decode the Block Header and initialize the filter chain. */ 4700578287ba49f36d031f6d61bb53f5b54f56c65a3repo syncstatic enum xz_ret dec_block_header(struct xz_dec *s) 4710578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync{ 4720578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync enum xz_ret ret; 4730578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 4740578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* 4750578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * Validate the CRC32. We know that the temp buffer is at least 4760578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * eight bytes so this is safe. 4770578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync */ 4780578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->temp.size -= 4; 4790578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (xz_crc32(s->temp.buf, s->temp.size, 0) 4800578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync != get_le32(s->temp.buf + s->temp.size)) 4810578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_DATA_ERROR; 4820578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 4830578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->temp.pos = 2; 4840578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 4850578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* 4860578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * Catch unsupported Block Flags. We support only one or two filters 4870578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * in the chain, so we catch that with the same test. 4880578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync */ 4890578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync#ifdef XZ_DEC_BCJ 4900578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (s->temp.buf[1] & 0x3E) 4910578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync#else 4920578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (s->temp.buf[1] & 0x3F) 4930578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync#endif 4940578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_OPTIONS_ERROR; 4950578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 4960578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* Compressed Size */ 4970578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (s->temp.buf[1] & 0x40) { 4980578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (dec_vli(s, s->temp.buf, &s->temp.pos, s->temp.size) 4990578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync != XZ_STREAM_END) 5000578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_DATA_ERROR; 5010578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 5020578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->block_header.compressed = s->vli; 5030578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync } else { 5040578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->block_header.compressed = VLI_UNKNOWN; 5050578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync } 5060578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 5070578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* Uncompressed Size */ 5080578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (s->temp.buf[1] & 0x80) { 5090578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (dec_vli(s, s->temp.buf, &s->temp.pos, s->temp.size) 5100578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync != XZ_STREAM_END) 5110578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_DATA_ERROR; 5120578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 5130578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->block_header.uncompressed = s->vli; 5140578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync } else { 5150578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->block_header.uncompressed = VLI_UNKNOWN; 5160578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync } 5170578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 5180578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync#ifdef XZ_DEC_BCJ 5190578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* If there are two filters, the first one must be a BCJ filter. */ 5200578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->bcj_active = s->temp.buf[1] & 0x01; 5210578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (s->bcj_active) { 5220578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (s->temp.size - s->temp.pos < 2) 5230578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_OPTIONS_ERROR; 5240578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 5250578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync ret = xz_dec_bcj_reset(s->bcj, s->temp.buf[s->temp.pos++]); 5260578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (ret != XZ_OK) 5270578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return ret; 5280578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 5290578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* 5300578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * We don't support custom start offset, 5310578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * so Size of Properties must be zero. 5320578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync */ 5330578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (s->temp.buf[s->temp.pos++] != 0x00) 5340578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_OPTIONS_ERROR; 5350578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync } 5360578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync#endif 5370578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 5380578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* Valid Filter Flags always take at least two bytes. */ 5390578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (s->temp.size - s->temp.pos < 2) 5400578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_DATA_ERROR; 5410578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 5420578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* Filter ID = LZMA2 */ 5430578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (s->temp.buf[s->temp.pos++] != 0x21) 5440578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_OPTIONS_ERROR; 5450578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 5460578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* Size of Properties = 1-byte Filter Properties */ 5470578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (s->temp.buf[s->temp.pos++] != 0x01) 5480578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_OPTIONS_ERROR; 5490578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 5500578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* Filter Properties contains LZMA2 dictionary size. */ 5510578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (s->temp.size - s->temp.pos < 1) 5520578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_DATA_ERROR; 5530578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 5540578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync ret = xz_dec_lzma2_reset(s->lzma2, s->temp.buf[s->temp.pos++]); 5550578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (ret != XZ_OK) 5560578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return ret; 5570578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 5580578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* The rest must be Header Padding. */ 5590578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync while (s->temp.pos < s->temp.size) 5600578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (s->temp.buf[s->temp.pos++] != 0x00) 5610578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_OPTIONS_ERROR; 5620578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 5630578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->temp.pos = 0; 5640578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->block.compressed = 0; 5650578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->block.uncompressed = 0; 5660578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 5670578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_OK; 5680578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync} 5690578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 5700578287ba49f36d031f6d61bb53f5b54f56c65a3repo syncstatic enum xz_ret dec_main(struct xz_dec *s, struct xz_buf *b) 5710578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync{ 5720578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync enum xz_ret ret; 5730578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 5740578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* 5750578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * Store the start position for the case when we are in the middle 5760578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * of the Index field. 5770578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync */ 5780578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->in_start = b->in_pos; 5790578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 5800578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync while (true) { 5810578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync switch (s->sequence) { 5820578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync case SEQ_STREAM_HEADER: 5830578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* 5840578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * Stream Header is copied to s->temp, and then 5850578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * decoded from there. This way if the caller 5860578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * gives us only little input at a time, we can 5870578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * still keep the Stream Header decoding code 5880578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * simple. Similar approach is used in many places 5890578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * in this file. 5900578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync */ 5910578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (!fill_temp(s, b)) 5920578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_OK; 5930578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 5940578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* 5950578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * If dec_stream_header() returns 5960578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * XZ_UNSUPPORTED_CHECK, it is still possible 5970578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * to continue decoding if working in multi-call 5980578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * mode. Thus, update s->sequence before calling 5990578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * dec_stream_header(). 6000578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync */ 6010578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->sequence = SEQ_BLOCK_START; 6020578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 6030578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync ret = dec_stream_header(s); 6040578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (ret != XZ_OK) 6050578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return ret; 6060578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 6070578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync case SEQ_BLOCK_START: 6080578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* We need one byte of input to continue. */ 6090578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (b->in_pos == b->in_size) 6100578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_OK; 6110578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 6120578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* See if this is the beginning of the Index field. */ 6130578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (b->in[b->in_pos] == 0) { 6140578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->in_start = b->in_pos++; 6150578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->sequence = SEQ_INDEX; 6160578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync break; 6170578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync } 6180578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 6190578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* 6200578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * Calculate the size of the Block Header and 6210578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * prepare to decode it. 6220578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync */ 6230578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->block_header.size 6240578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync = ((uint32_t)b->in[b->in_pos] + 1) * 4; 6250578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 6260578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->temp.size = s->block_header.size; 6270578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->temp.pos = 0; 6280578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->sequence = SEQ_BLOCK_HEADER; 6290578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 6300578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync case SEQ_BLOCK_HEADER: 6310578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (!fill_temp(s, b)) 6320578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_OK; 6330578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 6340578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync ret = dec_block_header(s); 6350578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (ret != XZ_OK) 6360578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return ret; 6370578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 6380578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->sequence = SEQ_BLOCK_UNCOMPRESS; 6390578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 6400578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync case SEQ_BLOCK_UNCOMPRESS: 6410578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync ret = dec_block(s, b); 6420578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (ret != XZ_STREAM_END) 6430578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return ret; 6440578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 6450578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->sequence = SEQ_BLOCK_PADDING; 6460578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 6470578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync case SEQ_BLOCK_PADDING: 6480578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* 6490578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * Size of Compressed Data + Block Padding 6500578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * must be a multiple of four. We don't need 6510578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * s->block.compressed for anything else 6520578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * anymore, so we use it here to test the size 6530578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * of the Block Padding field. 6540578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync */ 6550578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync while (s->block.compressed & 3) { 6560578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (b->in_pos == b->in_size) 6570578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_OK; 6580578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 6590578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (b->in[b->in_pos++] != 0) 6600578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_DATA_ERROR; 6610578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 6620578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync ++s->block.compressed; 6630578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync } 6640578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 6650578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->sequence = SEQ_BLOCK_CHECK; 6660578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 6670578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync case SEQ_BLOCK_CHECK: 6680578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (s->check_type == XZ_CHECK_CRC32) { 6690578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync ret = crc_validate(s, b, 32); 6700578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (ret != XZ_STREAM_END) 6710578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return ret; 6720578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync } 6730578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync else if (IS_CRC64(s->check_type)) { 6740578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync ret = crc_validate(s, b, 64); 6750578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (ret != XZ_STREAM_END) 6760578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return ret; 6770578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync } 6780578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync#ifdef XZ_DEC_ANY_CHECK 6790578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync else if (!check_skip(s, b)) { 6800578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_OK; 6810578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync } 6820578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync#endif 6830578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 6840578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->sequence = SEQ_BLOCK_START; 6850578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync break; 6860578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 6870578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync case SEQ_INDEX: 6880578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync ret = dec_index(s, b); 6890578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (ret != XZ_STREAM_END) 6900578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return ret; 6910578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 6920578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->sequence = SEQ_INDEX_PADDING; 6930578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 6940578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync case SEQ_INDEX_PADDING: 6950578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync while ((s->index.size + (b->in_pos - s->in_start)) 6960578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync & 3) { 6970578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (b->in_pos == b->in_size) { 6980578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync index_update(s, b); 6990578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_OK; 7000578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync } 7010578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 7020578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (b->in[b->in_pos++] != 0) 7030578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_DATA_ERROR; 7040578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync } 7050578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 7060578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* Finish the CRC32 value and Index size. */ 7070578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync index_update(s, b); 7080578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 7090578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* Compare the hashes to validate the Index field. */ 7100578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (!memeq(&s->block.hash, &s->index.hash, 7110578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync sizeof(s->block.hash))) 7120578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_DATA_ERROR; 7130578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 7140578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->sequence = SEQ_INDEX_CRC32; 7150578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 7160578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync case SEQ_INDEX_CRC32: 7170578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync ret = crc_validate(s, b, 32); 7180578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (ret != XZ_STREAM_END) 7190578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return ret; 7200578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 7210578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->temp.size = STREAM_HEADER_SIZE; 7220578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->sequence = SEQ_STREAM_FOOTER; 7230578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 7240578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync case SEQ_STREAM_FOOTER: 7250578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (!fill_temp(s, b)) 7260578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return XZ_OK; 7270578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 7280578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return dec_stream_footer(s); 7290578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync } 7300578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync } 7310578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 7320578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync /* Never reached */ 7330578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync} 7340578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 7350578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync/* 7360578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * xz_dec_run() is a wrapper for dec_main() to handle some special cases in 7370578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * multi-call and single-call decoding. 7380578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * 7390578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * In multi-call mode, we must return XZ_BUF_ERROR when it seems clear that we 7400578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * are not going to make any progress anymore. This is to prevent the caller 7410578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * from calling us infinitely when the input file is truncated or otherwise 7420578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * corrupt. Since zlib-style API allows that the caller fills the input buffer 7430578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * only when the decoder doesn't produce any new output, we have to be careful 7440578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * to avoid returning XZ_BUF_ERROR too easily: XZ_BUF_ERROR is returned only 7450578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * after the second consecutive call to xz_dec_run() that makes no progress. 7460578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * 7470578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * In single-call mode, if we couldn't decode everything and no error 7480578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * occurred, either the input is truncated or the output buffer is too small. 7490578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * Since we know that the last input byte never produces any output, we know 7500578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * that if all the input was consumed and decoding wasn't finished, the file 7510578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * must be corrupt. Otherwise the output buffer has to be too small or the 7520578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * file is corrupt in a way that decoding it produces too big output. 7530578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * 7540578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * If single-call decoding fails, we reset b->in_pos and b->out_pos back to 7550578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * their original values. This is because with some filter chains there won't 7560578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * be any valid uncompressed data in the output buffer unless the decoding 7570578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * actually succeeds (that's the price to pay of using the output buffer as 7580578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync * the workspace). 7590578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync */ 7600578287ba49f36d031f6d61bb53f5b54f56c65a3repo syncXZ_EXTERN enum xz_ret xz_dec_run(struct xz_dec *s, struct xz_buf *b) 7610578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync{ 7620578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync size_t in_start; 7630578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync size_t out_start; 7640578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync enum xz_ret ret; 7650578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 7660578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (DEC_IS_SINGLE(s->mode)) 7670578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync xz_dec_reset(s); 7680578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 7690578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync in_start = b->in_pos; 7700578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync out_start = b->out_pos; 7710578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync ret = dec_main(s, b); 7720578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 7730578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (DEC_IS_SINGLE(s->mode)) { 7740578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (ret == XZ_OK) 7750578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync ret = b->in_pos == b->in_size 7760578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync ? XZ_DATA_ERROR : XZ_BUF_ERROR; 7770578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 7780578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (ret != XZ_STREAM_END) { 7790578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync b->in_pos = in_start; 7800578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync b->out_pos = out_start; 7810578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync } 7820578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 7830578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync } else if (ret == XZ_OK && in_start == b->in_pos 7840578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync && out_start == b->out_pos) { 7850578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (s->allow_buf_error) 7860578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync ret = XZ_BUF_ERROR; 7870578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 7880578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->allow_buf_error = true; 7890578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync } else { 7900578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->allow_buf_error = false; 7910578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync } 7920578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 7930578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return ret; 7940578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync} 7950578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 7960578287ba49f36d031f6d61bb53f5b54f56c65a3repo syncXZ_EXTERN struct xz_dec *xz_dec_init(enum xz_mode mode, uint32_t dict_max) 7970578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync{ 7980578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync struct xz_dec *s = kmalloc(sizeof(*s), GFP_KERNEL); 7990578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (s == NULL) 8000578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return NULL; 8010578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 8020578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->mode = mode; 8030578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 8040578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync#ifdef XZ_DEC_BCJ 8050578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->bcj = xz_dec_bcj_create(DEC_IS_SINGLE(mode)); 8060578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (s->bcj == NULL) 8070578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync goto error_bcj; 8080578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync#endif 8090578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 8100578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->lzma2 = xz_dec_lzma2_create(mode, dict_max); 8110578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (s->lzma2 == NULL) 8120578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync goto error_lzma2; 8130578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 8140578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync xz_dec_reset(s); 8150578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return s; 8160578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 8170578287ba49f36d031f6d61bb53f5b54f56c65a3repo syncerror_lzma2: 8180578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync#ifdef XZ_DEC_BCJ 8190578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync xz_dec_bcj_end(s->bcj); 8200578287ba49f36d031f6d61bb53f5b54f56c65a3repo syncerror_bcj: 8210578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync#endif 8220578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync kfree(s); 8230578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync return NULL; 8240578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync} 8250578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 8260578287ba49f36d031f6d61bb53f5b54f56c65a3repo syncXZ_EXTERN void xz_dec_reset(struct xz_dec *s) 8270578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync{ 8280578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->sequence = SEQ_STREAM_HEADER; 8290578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->allow_buf_error = false; 8300578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->pos = 0; 8310578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->crc = 0; 8320578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync memzero(&s->block, sizeof(s->block)); 8330578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync memzero(&s->index, sizeof(s->index)); 8340578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->temp.pos = 0; 8350578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync s->temp.size = STREAM_HEADER_SIZE; 8360578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync} 8370578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync 8380578287ba49f36d031f6d61bb53f5b54f56c65a3repo syncXZ_EXTERN void xz_dec_end(struct xz_dec *s) 8390578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync{ 8400578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync if (s != NULL) { 8410578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync xz_dec_lzma2_end(s->lzma2); 8420578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync#ifdef XZ_DEC_BCJ 8430578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync xz_dec_bcj_end(s->bcj); 8440578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync#endif 8450578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync kfree(s); 8460578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync } 8470578287ba49f36d031f6d61bb53f5b54f56c65a3repo sync} 848