1 /*
2 version 20080912
3 D. J. Bernstein
4 Public domain.
5 */
6
7 #include <stdint.h>
8 #include <stdlib.h>
9
10 #include "crypto_core_hsalsa20.h"
11 #include "private/common.h"
12
13 #define ROUNDS 20
14 #define U32C(v) (v##U)
15
16 int
crypto_core_hsalsa20(unsigned char * out,const unsigned char * in,const unsigned char * k,const unsigned char * c)17 crypto_core_hsalsa20(unsigned char *out,
18 const unsigned char *in,
19 const unsigned char *k,
20 const unsigned char *c)
21 {
22 uint32_t x0, x1, x2, x3, x4, x5, x6, x7, x8,
23 x9, x10, x11, x12, x13, x14, x15;
24 int i;
25
26 if (c == NULL) {
27 x0 = U32C(0x61707865);
28 x5 = U32C(0x3320646e);
29 x10 = U32C(0x79622d32);
30 x15 = U32C(0x6b206574);
31 } else {
32 x0 = LOAD32_LE(c + 0);
33 x5 = LOAD32_LE(c + 4);
34 x10 = LOAD32_LE(c + 8);
35 x15 = LOAD32_LE(c + 12);
36 }
37 x1 = LOAD32_LE(k + 0);
38 x2 = LOAD32_LE(k + 4);
39 x3 = LOAD32_LE(k + 8);
40 x4 = LOAD32_LE(k + 12);
41 x11 = LOAD32_LE(k + 16);
42 x12 = LOAD32_LE(k + 20);
43 x13 = LOAD32_LE(k + 24);
44 x14 = LOAD32_LE(k + 28);
45 x6 = LOAD32_LE(in + 0);
46 x7 = LOAD32_LE(in + 4);
47 x8 = LOAD32_LE(in + 8);
48 x9 = LOAD32_LE(in + 12);
49
50 for (i = ROUNDS; i > 0; i -= 2) {
51 x4 ^= ROTL32(x0 + x12, 7);
52 x8 ^= ROTL32(x4 + x0, 9);
53 x12 ^= ROTL32(x8 + x4, 13);
54 x0 ^= ROTL32(x12 + x8, 18);
55 x9 ^= ROTL32(x5 + x1, 7);
56 x13 ^= ROTL32(x9 + x5, 9);
57 x1 ^= ROTL32(x13 + x9, 13);
58 x5 ^= ROTL32(x1 + x13, 18);
59 x14 ^= ROTL32(x10 + x6, 7);
60 x2 ^= ROTL32(x14 + x10, 9);
61 x6 ^= ROTL32(x2 + x14, 13);
62 x10 ^= ROTL32(x6 + x2, 18);
63 x3 ^= ROTL32(x15 + x11, 7);
64 x7 ^= ROTL32(x3 + x15, 9);
65 x11 ^= ROTL32(x7 + x3, 13);
66 x15 ^= ROTL32(x11 + x7, 18);
67 x1 ^= ROTL32(x0 + x3, 7);
68 x2 ^= ROTL32(x1 + x0, 9);
69 x3 ^= ROTL32(x2 + x1, 13);
70 x0 ^= ROTL32(x3 + x2, 18);
71 x6 ^= ROTL32(x5 + x4, 7);
72 x7 ^= ROTL32(x6 + x5, 9);
73 x4 ^= ROTL32(x7 + x6, 13);
74 x5 ^= ROTL32(x4 + x7, 18);
75 x11 ^= ROTL32(x10 + x9, 7);
76 x8 ^= ROTL32(x11 + x10, 9);
77 x9 ^= ROTL32(x8 + x11, 13);
78 x10 ^= ROTL32(x9 + x8, 18);
79 x12 ^= ROTL32(x15 + x14, 7);
80 x13 ^= ROTL32(x12 + x15, 9);
81 x14 ^= ROTL32(x13 + x12, 13);
82 x15 ^= ROTL32(x14 + x13, 18);
83 }
84
85 STORE32_LE(out + 0, x0);
86 STORE32_LE(out + 4, x5);
87 STORE32_LE(out + 8, x10);
88 STORE32_LE(out + 12, x15);
89 STORE32_LE(out + 16, x6);
90 STORE32_LE(out + 20, x7);
91 STORE32_LE(out + 24, x8);
92 STORE32_LE(out + 28, x9);
93
94 return 0;
95 }
96