1 | /* $NetBSD: ext2fs_hash.c,v 1.2 2016/08/13 07:40:10 christos Exp $ */ |
2 | |
3 | /*- |
4 | * Copyright (c) 2010, 2013 Zheng Liu <lz@freebsd.org> |
5 | * Copyright (c) 2012, Vyacheslav Matyushin |
6 | * All rights reserved. |
7 | * |
8 | * Redistribution and use in source and binary forms, with or without |
9 | * modification, are permitted provided that the following conditions |
10 | * are met: |
11 | * 1. Redistributions of source code must retain the above copyright |
12 | * notice, this list of conditions and the following disclaimer. |
13 | * 2. Redistributions in binary form must reproduce the above copyright |
14 | * notice, this list of conditions and the following disclaimer in the |
15 | * documentation and/or other materials provided with the distribution. |
16 | * |
17 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
18 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
19 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
20 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
21 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
22 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
23 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
24 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
25 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
26 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
27 | * SUCH DAMAGE. |
28 | * |
29 | * $FreeBSD: head/sys/fs/ext2fs/ext2_hash.c 294504 2016-01-21 14:50:28Z pfg $ |
30 | */ |
31 | |
32 | /* |
33 | * The following notice applies to the code in ext2_half_md4(): |
34 | * |
35 | * Copyright (C) 1990-2, RSA Data Security, Inc. All rights reserved. |
36 | * |
37 | * License to copy and use this software is granted provided that it |
38 | * is identified as the "RSA Data Security, Inc. MD4 Message-Digest |
39 | * Algorithm" in all material mentioning or referencing this software |
40 | * or this function. |
41 | * |
42 | * License is also granted to make and use derivative works provided |
43 | * that such works are identified as "derived from the RSA Data |
44 | * Security, Inc. MD4 Message-Digest Algorithm" in all material |
45 | * mentioning or referencing the derived work. |
46 | * |
47 | * RSA Data Security, Inc. makes no representations concerning either |
48 | * the merchantability of this software or the suitability of this |
49 | * software for any particular purpose. It is provided "as is" |
50 | * without express or implied warranty of any kind. |
51 | * |
52 | * These notices must be retained in any copies of any part of this |
53 | * documentation and/or software. |
54 | */ |
55 | |
56 | #include <sys/cdefs.h> |
57 | __KERNEL_RCSID(0, "$NetBSD: ext2fs_hash.c,v 1.2 2016/08/13 07:40:10 christos Exp $" ); |
58 | |
59 | #include <sys/param.h> |
60 | #include <sys/systm.h> |
61 | #include <sys/conf.h> |
62 | #include <sys/vnode.h> |
63 | #include <sys/stat.h> |
64 | #include <sys/mount.h> |
65 | |
66 | #include <ufs/ext2fs/ext2fs_htree.h> |
67 | #include <ufs/ext2fs/ext2fs_hash.h> |
68 | #include <ufs/ufs/inode.h> |
69 | #include <ufs/ufs/ufsmount.h> |
70 | #include <ufs/ext2fs/ext2fs_extern.h> |
71 | |
72 | /* |
73 | * FF, GG, and HH are transformations for rounds 1, 2, and 3. |
74 | * Rotation is separated from addition to prevent recomputation. |
75 | */ |
76 | #define FF(a, b, c, d, x, s) { \ |
77 | (a) += F ((b), (c), (d)) + (x); \ |
78 | (a) = ROTATE_LEFT ((a), (s)); \ |
79 | } |
80 | |
81 | #define GG(a, b, c, d, x, s) { \ |
82 | (a) += G ((b), (c), (d)) + (x) + (uint32_t)0x5A827999; \ |
83 | (a) = ROTATE_LEFT ((a), (s)); \ |
84 | } |
85 | |
86 | #define HH(a, b, c, d, x, s) { \ |
87 | (a) += H ((b), (c), (d)) + (x) + (uint32_t)0x6ED9EBA1; \ |
88 | (a) = ROTATE_LEFT ((a), (s)); \ |
89 | } |
90 | |
91 | static void |
92 | ext2fs_prep_hashbuf(const char *src, int slen, uint32_t *dst, int dlen, |
93 | int unsigned_char) |
94 | { |
95 | uint32_t padding = slen | (slen << 8) | (slen << 16) | (slen << 24); |
96 | uint32_t buf_val; |
97 | const unsigned char *ubuf = (const unsigned char *)src; |
98 | const signed char *sbuf = (const signed char *)src; |
99 | int len, i; |
100 | int buf_byte; |
101 | |
102 | if (slen > dlen) |
103 | len = dlen; |
104 | else |
105 | len = slen; |
106 | |
107 | buf_val = padding; |
108 | |
109 | for (i = 0; i < len; i++) { |
110 | if (unsigned_char) |
111 | buf_byte = (u_int)ubuf[i]; |
112 | else |
113 | buf_byte = (int)sbuf[i]; |
114 | |
115 | if ((i % 4) == 0) |
116 | buf_val = padding; |
117 | |
118 | buf_val <<= 8; |
119 | buf_val += buf_byte; |
120 | |
121 | if ((i % 4) == 3) { |
122 | *dst++ = buf_val; |
123 | dlen -= sizeof(uint32_t); |
124 | buf_val = padding; |
125 | } |
126 | } |
127 | |
128 | dlen -= sizeof(uint32_t); |
129 | if (dlen >= 0) |
130 | *dst++ = buf_val; |
131 | |
132 | dlen -= sizeof(uint32_t); |
133 | while (dlen >= 0) { |
134 | *dst++ = padding; |
135 | dlen -= sizeof(uint32_t); |
136 | } |
137 | } |
138 | |
139 | static uint32_t |
140 | ext2fs_legacy_hash(const char *name, int len, int unsigned_char) |
141 | { |
142 | uint32_t h0, h1 = 0x12A3FE2D, h2 = 0x37ABE8F9; |
143 | uint32_t multi = 0x6D22F5; |
144 | const unsigned char *uname = (const unsigned char *)name; |
145 | const signed char *sname = (const signed char *)name; |
146 | int val, i; |
147 | |
148 | for (i = 0; i < len; i++) { |
149 | if (unsigned_char) |
150 | val = (u_int)*uname++; |
151 | else |
152 | val = (int)*sname++; |
153 | |
154 | h0 = h2 + (h1 ^ (val * multi)); |
155 | if (h0 & 0x80000000) |
156 | h0 -= 0x7FFFFFFF; |
157 | h2 = h1; |
158 | h1 = h0; |
159 | } |
160 | |
161 | return h1 << 1; |
162 | } |
163 | |
164 | /* |
165 | * MD4 basic transformation. It transforms state based on block. |
166 | * |
167 | * This is a half md4 algorithm since Linux uses this algorithm for dir |
168 | * index. This function is derived from the RSA Data Security, Inc. MD4 |
169 | * Message-Digest Algorithm and was modified as necessary. |
170 | * |
171 | * The return value of this function is uint32_t in Linux, but actually we don't |
172 | * need to check this value, so in our version this function doesn't return any |
173 | * value. |
174 | */ |
175 | static void |
176 | ext2fs_half_md4(uint32_t hash[4], uint32_t data[8]) |
177 | { |
178 | uint32_t a = hash[0], b = hash[1], c = hash[2], d = hash[3]; |
179 | |
180 | /* Round 1 */ |
181 | FF(a, b, c, d, data[0], 3); |
182 | FF(d, a, b, c, data[1], 7); |
183 | FF(c, d, a, b, data[2], 11); |
184 | FF(b, c, d, a, data[3], 19); |
185 | FF(a, b, c, d, data[4], 3); |
186 | FF(d, a, b, c, data[5], 7); |
187 | FF(c, d, a, b, data[6], 11); |
188 | FF(b, c, d, a, data[7], 19); |
189 | |
190 | /* Round 2 */ |
191 | GG(a, b, c, d, data[1], 3); |
192 | GG(d, a, b, c, data[3], 5); |
193 | GG(c, d, a, b, data[5], 9); |
194 | GG(b, c, d, a, data[7], 13); |
195 | GG(a, b, c, d, data[0], 3); |
196 | GG(d, a, b, c, data[2], 5); |
197 | GG(c, d, a, b, data[4], 9); |
198 | GG(b, c, d, a, data[6], 13); |
199 | |
200 | /* Round 3 */ |
201 | HH(a, b, c, d, data[3], 3); |
202 | HH(d, a, b, c, data[7], 9); |
203 | HH(c, d, a, b, data[2], 11); |
204 | HH(b, c, d, a, data[6], 15); |
205 | HH(a, b, c, d, data[1], 3); |
206 | HH(d, a, b, c, data[5], 9); |
207 | HH(c, d, a, b, data[0], 11); |
208 | HH(b, c, d, a, data[4], 15); |
209 | |
210 | hash[0] += a; |
211 | hash[1] += b; |
212 | hash[2] += c; |
213 | hash[3] += d; |
214 | } |
215 | |
216 | /* |
217 | * Tiny Encryption Algorithm. |
218 | */ |
219 | static void |
220 | ext2fs_tea(uint32_t hash[4], uint32_t data[8]) |
221 | { |
222 | uint32_t tea_delta = 0x9E3779B9; |
223 | uint32_t sum; |
224 | uint32_t x = hash[0], y = hash[1]; |
225 | int n = 16; |
226 | int i = 1; |
227 | |
228 | while (n-- > 0) { |
229 | sum = i * tea_delta; |
230 | x += ((y << 4) + data[0]) ^ (y + sum) ^ ((y >> 5) + data[1]); |
231 | y += ((x << 4) + data[2]) ^ (x + sum) ^ ((x >> 5) + data[3]); |
232 | i++; |
233 | } |
234 | |
235 | hash[0] += x; |
236 | hash[1] += y; |
237 | } |
238 | |
239 | int |
240 | ext2fs_htree_hash(const char *name, int len, |
241 | uint32_t *hash_seed, int hash_version, |
242 | uint32_t *hash_major, uint32_t *hash_minor) |
243 | { |
244 | uint32_t hash[4]; |
245 | uint32_t data[8]; |
246 | uint32_t major = 0, minor = 0; |
247 | int unsigned_char = 0; |
248 | |
249 | if (!name || !hash_major) |
250 | return -1; |
251 | |
252 | if (len < 1 || len > 255) |
253 | goto error; |
254 | |
255 | hash[0] = 0x67452301; |
256 | hash[1] = 0xEFCDAB89; |
257 | hash[2] = 0x98BADCFE; |
258 | hash[3] = 0x10325476; |
259 | |
260 | if (hash_seed) |
261 | memcpy(hash, hash_seed, sizeof(hash)); |
262 | |
263 | switch (hash_version) { |
264 | case EXT2_HTREE_TEA_UNSIGNED: |
265 | unsigned_char = 1; |
266 | /* FALLTHROUGH */ |
267 | case EXT2_HTREE_TEA: |
268 | while (len > 0) { |
269 | ext2fs_prep_hashbuf(name, len, data, 16, unsigned_char); |
270 | ext2fs_tea(hash, data); |
271 | len -= 16; |
272 | name += 16; |
273 | } |
274 | major = hash[0]; |
275 | minor = hash[1]; |
276 | break; |
277 | case EXT2_HTREE_LEGACY_UNSIGNED: |
278 | unsigned_char = 1; |
279 | /* FALLTHROUGH */ |
280 | case EXT2_HTREE_LEGACY: |
281 | major = ext2fs_legacy_hash(name, len, unsigned_char); |
282 | break; |
283 | case EXT2_HTREE_HALF_MD4_UNSIGNED: |
284 | unsigned_char = 1; |
285 | /* FALLTHROUGH */ |
286 | case EXT2_HTREE_HALF_MD4: |
287 | while (len > 0) { |
288 | ext2fs_prep_hashbuf(name, len, data, 32, unsigned_char); |
289 | ext2fs_half_md4(hash, data); |
290 | len -= 32; |
291 | name += 32; |
292 | } |
293 | major = hash[1]; |
294 | minor = hash[2]; |
295 | break; |
296 | default: |
297 | goto error; |
298 | } |
299 | |
300 | major &= ~1; |
301 | if (major == (EXT2_HTREE_EOF << 1)) |
302 | major = (EXT2_HTREE_EOF - 1) << 1; |
303 | *hash_major = major; |
304 | if (hash_minor) |
305 | *hash_minor = minor; |
306 | |
307 | return 0; |
308 | |
309 | error: |
310 | *hash_major = 0; |
311 | if (hash_minor) |
312 | *hash_minor = 0; |
313 | return -1; |
314 | } |
315 | |