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      1 /* libFLAC - Free Lossless Audio Codec library
      2  * Copyright (C) 2000-2009  Josh Coalson
      3  * Copyright (C) 2011-2016  Xiph.Org Foundation
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  *
      9  * - Redistributions of source code must retain the above copyright
     10  * notice, this list of conditions and the following disclaimer.
     11  *
     12  * - Redistributions in binary form must reproduce the above copyright
     13  * notice, this list of conditions and the following disclaimer in the
     14  * documentation and/or other materials provided with the distribution.
     15  *
     16  * - Neither the name of the Xiph.org Foundation nor the names of its
     17  * contributors may be used to endorse or promote products derived from
     18  * this software without specific prior written permission.
     19  *
     20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     23  * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
     24  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     25  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     26  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     27  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
     28  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
     29  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
     30  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     31  */
     32 
     33 #ifdef HAVE_CONFIG_H
     34 #  include <config.h>
     35 #endif
     36 
     37 #include "private/crc.h"
     38 
     39 /* CRC-8, poly = x^8 + x^2 + x^1 + x^0, init = 0 */
     40 
     41 FLAC__byte const FLAC__crc8_table[256] = {
     42 	0x00, 0x07, 0x0E, 0x09, 0x1C, 0x1B, 0x12, 0x15,
     43 	0x38, 0x3F, 0x36, 0x31, 0x24, 0x23, 0x2A, 0x2D,
     44 	0x70, 0x77, 0x7E, 0x79, 0x6C, 0x6B, 0x62, 0x65,
     45 	0x48, 0x4F, 0x46, 0x41, 0x54, 0x53, 0x5A, 0x5D,
     46 	0xE0, 0xE7, 0xEE, 0xE9, 0xFC, 0xFB, 0xF2, 0xF5,
     47 	0xD8, 0xDF, 0xD6, 0xD1, 0xC4, 0xC3, 0xCA, 0xCD,
     48 	0x90, 0x97, 0x9E, 0x99, 0x8C, 0x8B, 0x82, 0x85,
     49 	0xA8, 0xAF, 0xA6, 0xA1, 0xB4, 0xB3, 0xBA, 0xBD,
     50 	0xC7, 0xC0, 0xC9, 0xCE, 0xDB, 0xDC, 0xD5, 0xD2,
     51 	0xFF, 0xF8, 0xF1, 0xF6, 0xE3, 0xE4, 0xED, 0xEA,
     52 	0xB7, 0xB0, 0xB9, 0xBE, 0xAB, 0xAC, 0xA5, 0xA2,
     53 	0x8F, 0x88, 0x81, 0x86, 0x93, 0x94, 0x9D, 0x9A,
     54 	0x27, 0x20, 0x29, 0x2E, 0x3B, 0x3C, 0x35, 0x32,
     55 	0x1F, 0x18, 0x11, 0x16, 0x03, 0x04, 0x0D, 0x0A,
     56 	0x57, 0x50, 0x59, 0x5E, 0x4B, 0x4C, 0x45, 0x42,
     57 	0x6F, 0x68, 0x61, 0x66, 0x73, 0x74, 0x7D, 0x7A,
     58 	0x89, 0x8E, 0x87, 0x80, 0x95, 0x92, 0x9B, 0x9C,
     59 	0xB1, 0xB6, 0xBF, 0xB8, 0xAD, 0xAA, 0xA3, 0xA4,
     60 	0xF9, 0xFE, 0xF7, 0xF0, 0xE5, 0xE2, 0xEB, 0xEC,
     61 	0xC1, 0xC6, 0xCF, 0xC8, 0xDD, 0xDA, 0xD3, 0xD4,
     62 	0x69, 0x6E, 0x67, 0x60, 0x75, 0x72, 0x7B, 0x7C,
     63 	0x51, 0x56, 0x5F, 0x58, 0x4D, 0x4A, 0x43, 0x44,
     64 	0x19, 0x1E, 0x17, 0x10, 0x05, 0x02, 0x0B, 0x0C,
     65 	0x21, 0x26, 0x2F, 0x28, 0x3D, 0x3A, 0x33, 0x34,
     66 	0x4E, 0x49, 0x40, 0x47, 0x52, 0x55, 0x5C, 0x5B,
     67 	0x76, 0x71, 0x78, 0x7F, 0x6A, 0x6D, 0x64, 0x63,
     68 	0x3E, 0x39, 0x30, 0x37, 0x22, 0x25, 0x2C, 0x2B,
     69 	0x06, 0x01, 0x08, 0x0F, 0x1A, 0x1D, 0x14, 0x13,
     70 	0xAE, 0xA9, 0xA0, 0xA7, 0xB2, 0xB5, 0xBC, 0xBB,
     71 	0x96, 0x91, 0x98, 0x9F, 0x8A, 0x8D, 0x84, 0x83,
     72 	0xDE, 0xD9, 0xD0, 0xD7, 0xC2, 0xC5, 0xCC, 0xCB,
     73 	0xE6, 0xE1, 0xE8, 0xEF, 0xFA, 0xFD, 0xF4, 0xF3
     74 };
     75 
     76 /* CRC-16, poly = x^16 + x^15 + x^2 + x^0, init = 0 */
     77 
     78 unsigned const FLAC__crc16_table[256] = {
     79 	0x0000,  0x8005,  0x800f,  0x000a,  0x801b,  0x001e,  0x0014,  0x8011,
     80 	0x8033,  0x0036,  0x003c,  0x8039,  0x0028,  0x802d,  0x8027,  0x0022,
     81 	0x8063,  0x0066,  0x006c,  0x8069,  0x0078,  0x807d,  0x8077,  0x0072,
     82 	0x0050,  0x8055,  0x805f,  0x005a,  0x804b,  0x004e,  0x0044,  0x8041,
     83 	0x80c3,  0x00c6,  0x00cc,  0x80c9,  0x00d8,  0x80dd,  0x80d7,  0x00d2,
     84 	0x00f0,  0x80f5,  0x80ff,  0x00fa,  0x80eb,  0x00ee,  0x00e4,  0x80e1,
     85 	0x00a0,  0x80a5,  0x80af,  0x00aa,  0x80bb,  0x00be,  0x00b4,  0x80b1,
     86 	0x8093,  0x0096,  0x009c,  0x8099,  0x0088,  0x808d,  0x8087,  0x0082,
     87 	0x8183,  0x0186,  0x018c,  0x8189,  0x0198,  0x819d,  0x8197,  0x0192,
     88 	0x01b0,  0x81b5,  0x81bf,  0x01ba,  0x81ab,  0x01ae,  0x01a4,  0x81a1,
     89 	0x01e0,  0x81e5,  0x81ef,  0x01ea,  0x81fb,  0x01fe,  0x01f4,  0x81f1,
     90 	0x81d3,  0x01d6,  0x01dc,  0x81d9,  0x01c8,  0x81cd,  0x81c7,  0x01c2,
     91 	0x0140,  0x8145,  0x814f,  0x014a,  0x815b,  0x015e,  0x0154,  0x8151,
     92 	0x8173,  0x0176,  0x017c,  0x8179,  0x0168,  0x816d,  0x8167,  0x0162,
     93 	0x8123,  0x0126,  0x012c,  0x8129,  0x0138,  0x813d,  0x8137,  0x0132,
     94 	0x0110,  0x8115,  0x811f,  0x011a,  0x810b,  0x010e,  0x0104,  0x8101,
     95 	0x8303,  0x0306,  0x030c,  0x8309,  0x0318,  0x831d,  0x8317,  0x0312,
     96 	0x0330,  0x8335,  0x833f,  0x033a,  0x832b,  0x032e,  0x0324,  0x8321,
     97 	0x0360,  0x8365,  0x836f,  0x036a,  0x837b,  0x037e,  0x0374,  0x8371,
     98 	0x8353,  0x0356,  0x035c,  0x8359,  0x0348,  0x834d,  0x8347,  0x0342,
     99 	0x03c0,  0x83c5,  0x83cf,  0x03ca,  0x83db,  0x03de,  0x03d4,  0x83d1,
    100 	0x83f3,  0x03f6,  0x03fc,  0x83f9,  0x03e8,  0x83ed,  0x83e7,  0x03e2,
    101 	0x83a3,  0x03a6,  0x03ac,  0x83a9,  0x03b8,  0x83bd,  0x83b7,  0x03b2,
    102 	0x0390,  0x8395,  0x839f,  0x039a,  0x838b,  0x038e,  0x0384,  0x8381,
    103 	0x0280,  0x8285,  0x828f,  0x028a,  0x829b,  0x029e,  0x0294,  0x8291,
    104 	0x82b3,  0x02b6,  0x02bc,  0x82b9,  0x02a8,  0x82ad,  0x82a7,  0x02a2,
    105 	0x82e3,  0x02e6,  0x02ec,  0x82e9,  0x02f8,  0x82fd,  0x82f7,  0x02f2,
    106 	0x02d0,  0x82d5,  0x82df,  0x02da,  0x82cb,  0x02ce,  0x02c4,  0x82c1,
    107 	0x8243,  0x0246,  0x024c,  0x8249,  0x0258,  0x825d,  0x8257,  0x0252,
    108 	0x0270,  0x8275,  0x827f,  0x027a,  0x826b,  0x026e,  0x0264,  0x8261,
    109 	0x0220,  0x8225,  0x822f,  0x022a,  0x823b,  0x023e,  0x0234,  0x8231,
    110 	0x8213,  0x0216,  0x021c,  0x8219,  0x0208,  0x820d,  0x8207,  0x0202
    111 };
    112 
    113 
    114 void FLAC__crc8_update(const FLAC__byte data, FLAC__uint8 *crc)
    115 {
    116 	*crc = FLAC__crc8_table[*crc ^ data];
    117 }
    118 
    119 void FLAC__crc8_update_block(const FLAC__byte *data, unsigned len, FLAC__uint8 *crc)
    120 {
    121 	while(len--)
    122 		*crc = FLAC__crc8_table[*crc ^ *data++];
    123 }
    124 
    125 FLAC__uint8 FLAC__crc8(const FLAC__byte *data, unsigned len)
    126 {
    127 	FLAC__uint8 crc = 0;
    128 
    129 	while(len--)
    130 		crc = FLAC__crc8_table[crc ^ *data++];
    131 
    132 	return crc;
    133 }
    134 
    135 unsigned FLAC__crc16(const FLAC__byte *data, unsigned len)
    136 {
    137 	unsigned crc = 0;
    138 
    139 	while(len--)
    140 		crc = ((crc<<8) ^ FLAC__crc16_table[(crc>>8) ^ *data++]) & 0xffff;
    141 
    142 	return crc;
    143 }
    144