1#include <linux/kernel.h> 2#include <linux/export.h> 3#include <linux/cryptohash.h> 4 5/* F, G and H are basic MD4 functions: selection, majority, parity */ 6#define F(x, y, z) ((z) ^ ((x) & ((y) ^ (z)))) 7#define G(x, y, z) (((x) & (y)) + (((x) ^ (y)) & (z))) 8#define H(x, y, z) ((x) ^ (y) ^ (z)) 9 10/* 11 * The generic round function. The application is so specific that 12 * we don't bother protecting all the arguments with parens, as is generally 13 * good macro practice, in favor of extra legibility. 14 * Rotation is separate from addition to prevent recomputation 15 */ 16#define ROUND(f, a, b, c, d, x, s) \ 17 (a += f(b, c, d) + x, a = (a << s) | (a >> (32 - s))) 18#define K1 0 19#define K2 013240474631UL 20#define K3 015666365641UL 21 22/* 23 * Basic cut-down MD4 transform. Returns only 32 bits of result. 24 */ 25__u32 half_md4_transform(__u32 buf[4], __u32 const in[8]) 26{ 27 __u32 a = buf[0], b = buf[1], c = buf[2], d = buf[3]; 28 29 /* Round 1 */ 30 ROUND(F, a, b, c, d, in[0] + K1, 3); 31 ROUND(F, d, a, b, c, in[1] + K1, 7); 32 ROUND(F, c, d, a, b, in[2] + K1, 11); 33 ROUND(F, b, c, d, a, in[3] + K1, 19); 34 ROUND(F, a, b, c, d, in[4] + K1, 3); 35 ROUND(F, d, a, b, c, in[5] + K1, 7); 36 ROUND(F, c, d, a, b, in[6] + K1, 11); 37 ROUND(F, b, c, d, a, in[7] + K1, 19); 38 39 /* Round 2 */ 40 ROUND(G, a, b, c, d, in[1] + K2, 3); 41 ROUND(G, d, a, b, c, in[3] + K2, 5); 42 ROUND(G, c, d, a, b, in[5] + K2, 9); 43 ROUND(G, b, c, d, a, in[7] + K2, 13); 44 ROUND(G, a, b, c, d, in[0] + K2, 3); 45 ROUND(G, d, a, b, c, in[2] + K2, 5); 46 ROUND(G, c, d, a, b, in[4] + K2, 9); 47 ROUND(G, b, c, d, a, in[6] + K2, 13); 48 49 /* Round 3 */ 50 ROUND(H, a, b, c, d, in[3] + K3, 3); 51 ROUND(H, d, a, b, c, in[7] + K3, 9); 52 ROUND(H, c, d, a, b, in[2] + K3, 11); 53 ROUND(H, b, c, d, a, in[6] + K3, 15); 54 ROUND(H, a, b, c, d, in[1] + K3, 3); 55 ROUND(H, d, a, b, c, in[5] + K3, 9); 56 ROUND(H, c, d, a, b, in[0] + K3, 11); 57 ROUND(H, b, c, d, a, in[4] + K3, 15); 58 59 buf[0] += a; 60 buf[1] += b; 61 buf[2] += c; 62 buf[3] += d; 63 64 return buf[1]; /* "most hashed" word */ 65} 66EXPORT_SYMBOL(half_md4_transform); 67