2 * Copyright (c) 2013 Grzegorz Kostka (kostka.grzegorz@gmail.com)
5 * Copyright (c) 2010, 2013 Zheng Liu <lz@freebsd.org>
6 * Copyright (c) 2012, Vyacheslav Matyushin
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * The following notice applies to the code in ext2_half_md4():
35 * Copyright (C) 1990-2, RSA Data Security, Inc. All rights reserved.
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
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.
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.
52 * These notices must be retained in any copies of any part of this
53 * documentation and/or software.
56 /** @addtogroup lwext4
61 * @brief Directory indexing hash functions.
64 #include "ext4_config.h"
65 #include "ext4_types.h"
66 #include "ext4_errno.h"
70 /* F, G, and H are MD4 functions */
71 #define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
72 #define G(x, y, z) (((x) & (y)) | ((x) & (z)) | ((y) & (z)))
73 #define H(x, y, z) ((x) ^ (y) ^ (z))
75 /* ROTATE_LEFT rotates x left n bits */
76 #define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32 - (n))))
79 * FF, GG, and HH are transformations for rounds 1, 2, and 3.
80 * Rotation is separated from addition to prevent recomputation.
82 #define FF(a, b, c, d, x, s) \
84 (a) += F((b), (c), (d)) + (x); \
85 (a) = ROTATE_LEFT((a), (s)); \
89 #define GG(a, b, c, d, x, s) \
91 (a) += G((b), (c), (d)) + (x) + (uint32_t)0x5A827999; \
92 (a) = ROTATE_LEFT((a), (s)); \
96 #define HH(a, b, c, d, x, s) \
98 (a) += H((b), (c), (d)) + (x) + (uint32_t)0x6ED9EBA1; \
99 (a) = ROTATE_LEFT((a), (s)); \
104 * MD4 basic transformation. It transforms state based on block.
106 * This is a half md4 algorithm since Linux uses this algorithm for dir
107 * index. This function is derived from the RSA Data Security, Inc. MD4
108 * Message-Digest Algorithm and was modified as necessary.
110 * The return value of this function is uint32_t in Linux, but actually we don't
111 * need to check this value, so in our version this function doesn't return any
114 static void ext2_half_md4(uint32_t hash[4], uint32_t data[8])
116 uint32_t a = hash[0], b = hash[1], c = hash[2], d = hash[3];
119 FF(a, b, c, d, data[0], 3);
120 FF(d, a, b, c, data[1], 7);
121 FF(c, d, a, b, data[2], 11);
122 FF(b, c, d, a, data[3], 19);
123 FF(a, b, c, d, data[4], 3);
124 FF(d, a, b, c, data[5], 7);
125 FF(c, d, a, b, data[6], 11);
126 FF(b, c, d, a, data[7], 19);
129 GG(a, b, c, d, data[1], 3);
130 GG(d, a, b, c, data[3], 5);
131 GG(c, d, a, b, data[5], 9);
132 GG(b, c, d, a, data[7], 13);
133 GG(a, b, c, d, data[0], 3);
134 GG(d, a, b, c, data[2], 5);
135 GG(c, d, a, b, data[4], 9);
136 GG(b, c, d, a, data[6], 13);
139 HH(a, b, c, d, data[3], 3);
140 HH(d, a, b, c, data[7], 9);
141 HH(c, d, a, b, data[2], 11);
142 HH(b, c, d, a, data[6], 15);
143 HH(a, b, c, d, data[1], 3);
144 HH(d, a, b, c, data[5], 9);
145 HH(c, d, a, b, data[0], 11);
146 HH(b, c, d, a, data[4], 15);
155 * Tiny Encryption Algorithm.
157 static void ext2_tea(uint32_t hash[4], uint32_t data[8])
159 uint32_t tea_delta = 0x9E3779B9;
161 uint32_t x = hash[0], y = hash[1];
167 x += ((y << 4) + data[0]) ^ (y + sum) ^ ((y >> 5) + data[1]);
168 y += ((x << 4) + data[2]) ^ (x + sum) ^ ((x >> 5) + data[3]);
176 static uint32_t ext2_legacy_hash(const char *name, int len, int unsigned_char)
178 uint32_t h0, h1 = 0x12A3FE2D, h2 = 0x37ABE8F9;
179 uint32_t multi = 0x6D22F5;
180 const unsigned char *uname = (const unsigned char *)name;
181 const signed char *sname = (const signed char *)name;
184 for (i = 0; i < len; i++) {
186 val = (unsigned int)*uname++;
190 h0 = h2 + (h1 ^ (val * multi));
200 static void ext2_prep_hashbuf(const char *src, uint32_t slen, uint32_t *dst,
201 int dlen, int unsigned_char)
203 uint32_t padding = slen | (slen << 8) | (slen << 16) | (slen << 24);
207 const unsigned char *ubuf = (const unsigned char *)src;
208 const signed char *sbuf = (const signed char *)src;
210 if (slen > (uint32_t)dlen)
217 for (i = 0; i < len; i++) {
219 buf_byte = (unsigned int)ubuf[i];
221 buf_byte = (int)sbuf[i];
231 dlen -= sizeof(uint32_t);
236 dlen -= sizeof(uint32_t);
240 dlen -= sizeof(uint32_t);
243 dlen -= sizeof(uint32_t);
247 int ext2_htree_hash(const char *name, int len, const uint32_t *hash_seed,
248 int hash_version, uint32_t *hash_major,
249 uint32_t *hash_minor)
253 uint32_t major = 0, minor = 0;
254 int unsigned_char = 0;
256 if (!name || !hash_major)
259 if (len < 1 || len > 255)
262 hash[0] = 0x67452301;
263 hash[1] = 0xEFCDAB89;
264 hash[2] = 0x98BADCFE;
265 hash[3] = 0x10325476;
268 memcpy(hash, hash_seed, sizeof(hash));
270 switch (hash_version) {
271 case EXT2_HTREE_TEA_UNSIGNED:
275 ext2_prep_hashbuf(name, len, data, 16, unsigned_char);
276 ext2_tea(hash, data);
283 case EXT2_HTREE_LEGACY_UNSIGNED:
285 case EXT2_HTREE_LEGACY:
286 major = ext2_legacy_hash(name, len, unsigned_char);
288 case EXT2_HTREE_HALF_MD4_UNSIGNED:
290 case EXT2_HTREE_HALF_MD4:
292 ext2_prep_hashbuf(name, len, data, 32, unsigned_char);
293 ext2_half_md4(hash, data);
305 if (major == (EXT2_HTREE_EOF << 1))
306 major = (EXT2_HTREE_EOF - 1) << 1;