3 * Keyed 32-bit hash function using TEA in a Davis-Meyer function
5 * Hi = E Mi(Hi-1) + Hi-1
7 * (see Applied Cryptography, 2nd edition, p448).
9 * Jeremy Fitzhardinge <jeremy@zip.com.au> 1998
11 * Jeremy has agreed to the contents of reiserfs/README. -Hans
12 * Yura's function is added (04/07/2000)
21 #include <linux/kernel.h>
22 #include <linux/reiserfs_fs.h>
23 #include <asm/types.h>
25 #define DELTA 0x9E3779B9
26 #define FULLROUNDS 10 /* 32 is overkill, 16 is strong crypto */
27 #define PARTROUNDS 6 /* 6 gets complete mixing */
29 /* a, b, c, d - data; h0, h1 - accumulated hash */
30 #define TEACORE(rounds) \
42 b0 += ((b1 << 4)+a) ^ (b1+sum) ^ ((b1 >> 5)+b); \
43 b1 += ((b0 << 4)+c) ^ (b0+sum) ^ ((b0 >> 5)+d); \
50 u32 keyed_hash(const signed char *msg, int len)
52 u32 k[] = { 0x9464a485, 0x542e1a94, 0x3e846bff, 0xb75bcfc3 };
54 u32 h0 = k[0], h1 = k[1];
59 // assert(len >= 0 && len < 256);
61 pad = (u32) len | ((u32) len << 8);
66 (u32) msg[1] << 8 | (u32) msg[2] << 16 | (u32) msg[3] << 24;
68 (u32) msg[5] << 8 | (u32) msg[6] << 16 | (u32) msg[7] << 24;
71 (u32) msg[10] << 16 | (u32) msg[11] << 24;
74 (u32) msg[14] << 16 | (u32) msg[15] << 24;
84 (u32) msg[1] << 8 | (u32) msg[2] << 16 | (u32) msg[3] << 24;
86 (u32) msg[5] << 8 | (u32) msg[6] << 16 | (u32) msg[7] << 24;
89 (u32) msg[10] << 16 | (u32) msg[11] << 24;
92 for (i = 12; i < len; i++) {
96 } else if (len >= 8) {
98 (u32) msg[1] << 8 | (u32) msg[2] << 16 | (u32) msg[3] << 24;
100 (u32) msg[5] << 8 | (u32) msg[6] << 16 | (u32) msg[7] << 24;
103 for (i = 8; i < len; i++) {
107 } else if (len >= 4) {
109 (u32) msg[1] << 8 | (u32) msg[2] << 16 | (u32) msg[3] << 24;
112 for (i = 4; i < len; i++) {
118 for (i = 0; i < len; i++) {
130 /* What follows in this file is copyright 2000 by Hans Reiser, and the
131 * licensing of what follows is governed by reiserfs/README */
133 u32 yura_hash(const signed char *msg, int len)
139 for (pow = 1, i = 1; i < len; i++)
145 a = (msg[0] - 48) * pow;
147 for (i = 1; i < len; i++) {
149 for (pow = 1, j = i; j < len - 1; j++)
154 for (; i < 40; i++) {
156 for (pow = 1, j = i; j < len - 1; j++)
161 for (; i < 256; i++) {
163 for (pow = 1, j = i; j < len - 1; j++)
172 u32 r5_hash(const signed char *msg, int len)