1 /* 2 * Copyright 2005 Sun Microsystems, Inc. All rights reserved. 3 * Use is subject to license terms. 4 */ 5 6 #pragma ident "%Z%%M% %I% %E% SMI" 7 8 /* 9 * lib/crypto/crc32/crc.c 10 * 11 * Copyright 1990, 2002 by the Massachusetts Institute of Technology. 12 * All Rights Reserved. 13 * 14 * Export of this software from the United States of America may 15 * require a specific license from the United States Government. 16 * It is the responsibility of any person or organization contemplating 17 * export to obtain such a license before exporting. 18 * 19 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and 20 * distribute this software and its documentation for any purpose and 21 * without fee is hereby granted, provided that the above copyright 22 * notice appear in all copies and that both that copyright notice and 23 * this permission notice appear in supporting documentation, and that 24 * the name of M.I.T. not be used in advertising or publicity pertaining 25 * to distribution of the software without specific, written prior 26 * permission. M.I.T. makes no representations about the suitability of 27 * this software for any purpose. It is provided "as is" without express 28 * or implied warranty. 29 * 30 * 31 * CRC-32/AUTODIN-II routines 32 */ 33 34 #include <k5-int.h> 35 #include <crc-32.h> 36 37 /* This table and block of comments are taken from code labeled: */ 38 /* 39 * Copyright (C) 1986 Gary S. Brown. You may use this program, or 40 * code or tables extracted from it, as desired without restriction. 41 */ 42 43 /* First, the polynomial itself and its table of feedback terms. The */ 44 /* polynomial is */ 45 /* X^32+X^26+X^23+X^22+X^16+X^12+X^11+X^10+X^8+X^7+X^5+X^4+X^2+X^1+X^0 */ 46 /* Note that we take it "backwards" and put the highest-order term in */ 47 /* the lowest-order bit. The X^32 term is "implied"; the LSB is the */ 48 /* X^31 term, etc. The X^0 term (usually shown as "+1") results in */ 49 /* the MSB being 1. */ 50 51 /* Note that the usual hardware shift register implementation, which */ 52 /* is what we're using (we're merely optimizing it by doing eight-bit */ 53 /* chunks at a time) shifts bits into the lowest-order term. In our */ 54 /* implementation, that means shifting towards the right. Why do we */ 55 /* do it this way? Because the calculated CRC must be transmitted in */ 56 /* order from highest-order term to lowest-order term. UARTs transmit */ 57 /* characters in order from LSB to MSB. By storing the CRC this way, */ 58 /* we hand it to the UART in the order low-byte to high-byte; the UART */ 59 /* sends each low-bit to hight-bit; and the result is transmission bit */ 60 /* by bit from highest- to lowest-order term without requiring any bit */ 61 /* shuffling on our part. Reception works similarly. */ 62 63 /* The feedback terms table consists of 256, 32-bit entries. Notes: */ 64 /* */ 65 /* 1. The table can be generated at runtime if desired; code to do so */ 66 /* is shown later. It might not be obvious, but the feedback */ 67 /* terms simply represent the results of eight shift/xor opera- */ 68 /* tions for all combinations of data and CRC register values. */ 69 /* */ 70 /* 2. The CRC accumulation logic is the same for all CRC polynomials, */ 71 /* be they sixteen or thirty-two bits wide. You simply choose the */ 72 /* appropriate table. Alternatively, because the table can be */ 73 /* generated at runtime, you can start by generating the table for */ 74 /* the polynomial in question and use exactly the same "updcrc", */ 75 /* if your application needn't simultaneously handle two CRC */ 76 /* polynomials. (Note, however, that XMODEM is strange.) */ 77 /* */ 78 /* 3. For 16-bit CRCs, the table entries need be only 16 bits wide; */ 79 /* of course, 32-bit entries work OK if the high 16 bits are zero. */ 80 /* */ 81 /* 4. The values must be right-shifted by eight bits by the "updcrc" */ 82 /* logic; the shift must be unsigned (bring in zeroes). On some */ 83 /* hardware you could probably optimize the shift in assembler by */ 84 /* using byte-swap instructions. */ 85 86 static uint32_t const crc_table[256] = { 87 0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 88 0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3, 89 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988, 90 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, 91 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, 92 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 93 0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 94 0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5, 95 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172, 96 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 97 0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 98 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59, 99 0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 100 0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f, 101 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, 102 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 103 0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a, 104 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433, 105 0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 106 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01, 107 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 108 0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 109 0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, 0xfcb9887c, 110 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65, 111 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 112 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 113 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0, 114 0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, 115 0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086, 116 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f, 117 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 118 0x59b33d17, 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, 119 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a, 120 0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, 121 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, 122 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 123 0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 124 0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7, 125 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc, 126 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 127 0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 128 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b, 129 0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 130 0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79, 131 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, 132 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 133 0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 134 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d, 135 0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 136 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713, 137 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 138 0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 139 0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e, 140 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777, 141 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 142 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 143 0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 144 0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, 145 0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0, 146 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9, 147 0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 148 0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf, 149 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94, 150 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d 151 }; 152 153 /* Windows needs to these prototypes for crc32_cksumtable_entry below */ 154 155 static krb5_error_code 156 crc32_sum_func ( 157 krb5_const krb5_pointer in, 158 krb5_const size_t in_length, 159 krb5_const krb5_pointer seed, 160 krb5_const size_t seed_length, 161 krb5_checksum *outcksum); 162 163 static krb5_error_code 164 crc32_verify_func ( 165 krb5_const krb5_checksum *cksum, 166 krb5_const krb5_pointer in, 167 krb5_const size_t in_length, 168 krb5_const krb5_pointer seed, 169 krb5_const size_t seed_length); 170 171 /*ARGSUSED*/ 172 static krb5_error_code 173 crc32_sum_func(in, in_length, seed, seed_length, outcksum) 174 krb5_const krb5_pointer in; 175 krb5_const size_t in_length; 176 krb5_const krb5_pointer seed; 177 krb5_const size_t seed_length; 178 krb5_checksum *outcksum; 179 { 180 register u_char *data; 181 register u_long c = 0; 182 register int idx; 183 size_t i; 184 185 if (outcksum->length < CRC32_CKSUM_LENGTH) 186 return KRB5_BAD_MSIZE; 187 188 data = (u_char *)in; 189 for (i = 0; i < in_length; i++) { 190 idx = (int) (data[i] ^ c); 191 idx &= 0xff; 192 c >>= 8; 193 c ^= (u_long) crc_table[idx]; 194 } 195 /* c now holds the result */ 196 outcksum->checksum_type = CKSUMTYPE_CRC32; 197 outcksum->length = CRC32_CKSUM_LENGTH; 198 outcksum->contents[0] = (krb5_octet) (c & 0xff); 199 outcksum->contents[1] = (krb5_octet) ((c >> 8) & 0xff); 200 outcksum->contents[2] = (krb5_octet) ((c >> 16) & 0xff); 201 outcksum->contents[3] = (krb5_octet) ((c >> 24) & 0xff); 202 return 0; 203 } 204 205 /*ARGSUSED*/ 206 static krb5_error_code 207 crc32_verify_func(cksum, in, in_length, seed, seed_length) 208 krb5_const krb5_checksum *cksum; 209 krb5_const krb5_pointer in; 210 krb5_const size_t in_length; 211 krb5_const krb5_pointer seed; 212 krb5_const size_t seed_length; 213 { 214 register u_char *data; 215 register u_long c = 0; 216 register int idx; 217 size_t i; 218 krb5_error_code retval; 219 220 retval = 0; 221 if (cksum->checksum_type == CKSUMTYPE_CRC32) { 222 if (cksum->length == CRC32_CKSUM_LENGTH) { 223 data = (u_char *)in; 224 for (i = 0; i < in_length; i++) { 225 idx = (int) (data[i] ^ c); 226 idx &= 0xff; 227 c >>= 8; 228 c ^= (u_long) crc_table[idx]; 229 } 230 if ((cksum->contents[0] != (krb5_octet) (c & 0xff)) || 231 (cksum->contents[1] != (krb5_octet) ((c >> 8) & 0xff)) || 232 (cksum->contents[2] != (krb5_octet) ((c >> 16) & 0xff)) || 233 (cksum->contents[3] != (krb5_octet) ((c >> 24) & 0xff))) 234 retval = KRB5KRB_AP_ERR_BAD_INTEGRITY; 235 } 236 else 237 retval = KRB5KRB_AP_ERR_BAD_INTEGRITY; 238 } 239 else 240 retval = KRB5KRB_AP_ERR_INAPP_CKSUM; 241 return(retval); 242 } 243 244