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