Line data    Source code

       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       24476 : __u32 half_md4_transform(__u32 buf[4], __u32 const in[8])
      26             : {
      27       24476 :         __u32 a = buf[0], b = buf[1], c = buf[2], d = buf[3];
      28             : 
      29             :         /* Round 1 */
      30       24476 :         ROUND(F, a, b, c, d, in[0] + K1,  3);
      31       24476 :         ROUND(F, d, a, b, c, in[1] + K1,  7);
      32       24476 :         ROUND(F, c, d, a, b, in[2] + K1, 11);
      33       24476 :         ROUND(F, b, c, d, a, in[3] + K1, 19);
      34       24476 :         ROUND(F, a, b, c, d, in[4] + K1,  3);
      35       24476 :         ROUND(F, d, a, b, c, in[5] + K1,  7);
      36       24476 :         ROUND(F, c, d, a, b, in[6] + K1, 11);
      37       24476 :         ROUND(F, b, c, d, a, in[7] + K1, 19);
      38             : 
      39             :         /* Round 2 */
      40       24476 :         ROUND(G, a, b, c, d, in[1] + K2,  3);
      41       24476 :         ROUND(G, d, a, b, c, in[3] + K2,  5);
      42       24476 :         ROUND(G, c, d, a, b, in[5] + K2,  9);
      43       24476 :         ROUND(G, b, c, d, a, in[7] + K2, 13);
      44       24476 :         ROUND(G, a, b, c, d, in[0] + K2,  3);
      45       24476 :         ROUND(G, d, a, b, c, in[2] + K2,  5);
      46       24476 :         ROUND(G, c, d, a, b, in[4] + K2,  9);
      47       24476 :         ROUND(G, b, c, d, a, in[6] + K2, 13);
      48             : 
      49             :         /* Round 3 */
      50       24476 :         ROUND(H, a, b, c, d, in[3] + K3,  3);
      51       24476 :         ROUND(H, d, a, b, c, in[7] + K3,  9);
      52       24476 :         ROUND(H, c, d, a, b, in[2] + K3, 11);
      53       24476 :         ROUND(H, b, c, d, a, in[6] + K3, 15);
      54       24476 :         ROUND(H, a, b, c, d, in[1] + K3,  3);
      55       24476 :         ROUND(H, d, a, b, c, in[5] + K3,  9);
      56       24476 :         ROUND(H, c, d, a, b, in[0] + K3, 11);
      57       24476 :         ROUND(H, b, c, d, a, in[4] + K3, 15);
      58             : 
      59       24476 :         buf[0] += a;
      60       24476 :         buf[1] += b;
      61       24476 :         buf[2] += c;
      62       24476 :         buf[3] += d;
      63             : 
      64       24476 :         return buf[1]; /* "most hashed" word */
      65             : }
      66             : EXPORT_SYMBOL(half_md4_transform);