1/* 2version 20080912 3D. J. Bernstein 4Public 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 16int 17crypto_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