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Diffstat (limited to 'e2fsprogs/ext2fs/dirhash.c')
| -rw-r--r-- | e2fsprogs/ext2fs/dirhash.c | 234 |
1 files changed, 0 insertions, 234 deletions
diff --git a/e2fsprogs/ext2fs/dirhash.c b/e2fsprogs/ext2fs/dirhash.c deleted file mode 100644 index ab3243f..0000000 --- a/e2fsprogs/ext2fs/dirhash.c +++ /dev/null @@ -1,234 +0,0 @@ -/* vi: set sw=4 ts=4: */ -/* - * dirhash.c -- Calculate the hash of a directory entry - * - * Copyright (c) 2001 Daniel Phillips - * - * Copyright (c) 2002 Theodore Ts'o. - * - * %Begin-Header% - * This file may be redistributed under the terms of the GNU Public - * License. - * %End-Header% - */ - -#include <stdio.h> -#include <string.h> - -#include "ext2_fs.h" -#include "ext2fs.h" - -/* - * Keyed 32-bit hash function using TEA in a Davis-Meyer function - * H0 = Key - * Hi = E Mi(Hi-1) + Hi-1 - * - * (see Applied Cryptography, 2nd edition, p448). - * - * Jeremy Fitzhardinge <jeremy@zip.com.au> 1998 - * - * This code is made available under the terms of the GPL - */ -#define DELTA 0x9E3779B9 - -static void TEA_transform(__u32 buf[4], __u32 const in[]) -{ - __u32 sum = 0; - __u32 b0 = buf[0], b1 = buf[1]; - __u32 a = in[0], b = in[1], c = in[2], d = in[3]; - int n = 16; - - do { - sum += DELTA; - b0 += ((b1 << 4)+a) ^ (b1+sum) ^ ((b1 >> 5)+b); - b1 += ((b0 << 4)+c) ^ (b0+sum) ^ ((b0 >> 5)+d); - } while(--n); - - buf[0] += b0; - buf[1] += b1; -} - -/* F, G and H are basic MD4 functions: selection, majority, parity */ -#define F(x, y, z) ((z) ^ ((x) & ((y) ^ (z)))) -#define G(x, y, z) (((x) & (y)) + (((x) ^ (y)) & (z))) -#define H(x, y, z) ((x) ^ (y) ^ (z)) - -/* - * The generic round function. The application is so specific that - * we don't bother protecting all the arguments with parens, as is generally - * good macro practice, in favor of extra legibility. - * Rotation is separate from addition to prevent recomputation - */ -#define ROUND(f, a, b, c, d, x, s) \ - (a += f(b, c, d) + x, a = (a << s) | (a >> (32-s))) -#define K1 0 -#define K2 013240474631UL -#define K3 015666365641UL - -/* - * Basic cut-down MD4 transform. Returns only 32 bits of result. - */ -static void halfMD4Transform (__u32 buf[4], __u32 const in[]) -{ - __u32 a = buf[0], b = buf[1], c = buf[2], d = buf[3]; - - /* Round 1 */ - ROUND(F, a, b, c, d, in[0] + K1, 3); - ROUND(F, d, a, b, c, in[1] + K1, 7); - ROUND(F, c, d, a, b, in[2] + K1, 11); - ROUND(F, b, c, d, a, in[3] + K1, 19); - ROUND(F, a, b, c, d, in[4] + K1, 3); - ROUND(F, d, a, b, c, in[5] + K1, 7); - ROUND(F, c, d, a, b, in[6] + K1, 11); - ROUND(F, b, c, d, a, in[7] + K1, 19); - - /* Round 2 */ - ROUND(G, a, b, c, d, in[1] + K2, 3); - ROUND(G, d, a, b, c, in[3] + K2, 5); - ROUND(G, c, d, a, b, in[5] + K2, 9); - ROUND(G, b, c, d, a, in[7] + K2, 13); - ROUND(G, a, b, c, d, in[0] + K2, 3); - ROUND(G, d, a, b, c, in[2] + K2, 5); - ROUND(G, c, d, a, b, in[4] + K2, 9); - ROUND(G, b, c, d, a, in[6] + K2, 13); - - /* Round 3 */ - ROUND(H, a, b, c, d, in[3] + K3, 3); - ROUND(H, d, a, b, c, in[7] + K3, 9); - ROUND(H, c, d, a, b, in[2] + K3, 11); - ROUND(H, b, c, d, a, in[6] + K3, 15); - ROUND(H, a, b, c, d, in[1] + K3, 3); - ROUND(H, d, a, b, c, in[5] + K3, 9); - ROUND(H, c, d, a, b, in[0] + K3, 11); - ROUND(H, b, c, d, a, in[4] + K3, 15); - - buf[0] += a; - buf[1] += b; - buf[2] += c; - buf[3] += d; -} - -#undef ROUND -#undef F -#undef G -#undef H -#undef K1 -#undef K2 -#undef K3 - -/* The old legacy hash */ -static ext2_dirhash_t dx_hack_hash (const char *name, int len) -{ - __u32 hash0 = 0x12a3fe2d, hash1 = 0x37abe8f9; - while (len--) { - __u32 hash = hash1 + (hash0 ^ (*name++ * 7152373)); - - if (hash & 0x80000000) hash -= 0x7fffffff; - hash1 = hash0; - hash0 = hash; - } - return (hash0 << 1); -} - -static void str2hashbuf(const char *msg, int len, __u32 *buf, int num) -{ - __u32 pad, val; - int i; - - pad = (__u32)len | ((__u32)len << 8); - pad |= pad << 16; - - val = pad; - if (len > num*4) - len = num * 4; - for (i=0; i < len; i++) { - if ((i % 4) == 0) - val = pad; - val = msg[i] + (val << 8); - if ((i % 4) == 3) { - *buf++ = val; - val = pad; - num--; - } - } - if (--num >= 0) - *buf++ = val; - while (--num >= 0) - *buf++ = pad; -} - -/* - * Returns the hash of a filename. If len is 0 and name is NULL, then - * this function can be used to test whether or not a hash version is - * supported. - * - * The seed is an 4 longword (32 bits) "secret" which can be used to - * uniquify a hash. If the seed is all zero's, then some default seed - * may be used. - * - * A particular hash version specifies whether or not the seed is - * represented, and whether or not the returned hash is 32 bits or 64 - * bits. 32 bit hashes will return 0 for the minor hash. - */ -errcode_t ext2fs_dirhash(int version, const char *name, int len, - const __u32 *seed, - ext2_dirhash_t *ret_hash, - ext2_dirhash_t *ret_minor_hash) -{ - __u32 hash; - __u32 minor_hash = 0; - const char *p; - int i; - __u32 in[8], buf[4]; - - /* Initialize the default seed for the hash checksum functions */ - buf[0] = 0x67452301; - buf[1] = 0xefcdab89; - buf[2] = 0x98badcfe; - buf[3] = 0x10325476; - - /* Check to see if the seed is all zero's */ - if (seed) { - for (i=0; i < 4; i++) { - if (seed[i]) - break; - } - if (i < 4) - memcpy(buf, seed, sizeof(buf)); - } - - switch (version) { - case EXT2_HASH_LEGACY: - hash = dx_hack_hash(name, len); - break; - case EXT2_HASH_HALF_MD4: - p = name; - while (len > 0) { - str2hashbuf(p, len, in, 8); - halfMD4Transform(buf, in); - len -= 32; - p += 32; - } - minor_hash = buf[2]; - hash = buf[1]; - break; - case EXT2_HASH_TEA: - p = name; - while (len > 0) { - str2hashbuf(p, len, in, 4); - TEA_transform(buf, in); - len -= 16; - p += 16; - } - hash = buf[0]; - minor_hash = buf[1]; - break; - default: - *ret_hash = 0; - return EXT2_ET_DIRHASH_UNSUPP; - } - *ret_hash = hash & ~1; - if (ret_minor_hash) - *ret_minor_hash = minor_hash; - return 0; -} |