1 /*
2 * version 20110505
3 * D. J. Bernstein
4 * Public domain.
5 *
6 * Based on crypto_core/salsa208/armneon/core.c from SUPERCOP 20130419
7 */
8
9 #define ROUNDS 8
10 static void
salsa20_8_intrinsic(void * input)11 salsa20_8_intrinsic(void * input)
12 {
13 int i;
14
15 const uint32x4_t abab = {-1,0,-1,0};
16
17 /*
18 * This is modified since we only have one argument. Usually you'd rearrange
19 * the constant, key, and input bytes, but we just have one linear array to
20 * rearrange which is a bit easier.
21 */
22
23 /*
24 * Change the input to be diagonals as if it's a 4x4 matrix of 32-bit values.
25 */
26 uint32x4_t x0x5x10x15;
27 uint32x4_t x12x1x6x11;
28 uint32x4_t x8x13x2x7;
29 uint32x4_t x4x9x14x3;
30
31 uint32x4_t x0x1x10x11;
32 uint32x4_t x12x13x6x7;
33 uint32x4_t x8x9x2x3;
34 uint32x4_t x4x5x14x15;
35
36 uint32x4_t x0x1x2x3;
37 uint32x4_t x4x5x6x7;
38 uint32x4_t x8x9x10x11;
39 uint32x4_t x12x13x14x15;
40
41 x0x1x2x3 = vld1q_u8((uint8_t *) input);
42 x4x5x6x7 = vld1q_u8(16 + (uint8_t *) input);
43 x8x9x10x11 = vld1q_u8(32 + (uint8_t *) input);
44 x12x13x14x15 = vld1q_u8(48 + (uint8_t *) input);
45
46 x0x1x10x11 = vcombine_u32(vget_low_u32(x0x1x2x3), vget_high_u32(x8x9x10x11));
47 x4x5x14x15 = vcombine_u32(vget_low_u32(x4x5x6x7), vget_high_u32(x12x13x14x15));
48 x8x9x2x3 = vcombine_u32(vget_low_u32(x8x9x10x11), vget_high_u32(x0x1x2x3));
49 x12x13x6x7 = vcombine_u32(vget_low_u32(x12x13x14x15), vget_high_u32(x4x5x6x7));
50
51 x0x5x10x15 = vbslq_u32(abab,x0x1x10x11,x4x5x14x15);
52 x8x13x2x7 = vbslq_u32(abab,x8x9x2x3,x12x13x6x7);
53 x4x9x14x3 = vbslq_u32(abab,x4x5x14x15,x8x9x2x3);
54 x12x1x6x11 = vbslq_u32(abab,x12x13x6x7,x0x1x10x11);
55
56 uint32x4_t start0 = x0x5x10x15;
57 uint32x4_t start1 = x12x1x6x11;
58 uint32x4_t start3 = x4x9x14x3;
59 uint32x4_t start2 = x8x13x2x7;
60
61 /* From here on this should be the same as the SUPERCOP version. */
62
63 uint32x4_t diag0 = start0;
64 uint32x4_t diag1 = start1;
65 uint32x4_t diag2 = start2;
66 uint32x4_t diag3 = start3;
67
68 uint32x4_t a0;
69 uint32x4_t a1;
70 uint32x4_t a2;
71 uint32x4_t a3;
72
73 for (i = ROUNDS;i > 0;i -= 2) {
74 a0 = diag1 + diag0;
75 diag3 ^= vsriq_n_u32(vshlq_n_u32(a0,7),a0,25);
76 a1 = diag0 + diag3;
77 diag2 ^= vsriq_n_u32(vshlq_n_u32(a1,9),a1,23);
78 a2 = diag3 + diag2;
79 diag1 ^= vsriq_n_u32(vshlq_n_u32(a2,13),a2,19);
80 a3 = diag2 + diag1;
81 diag0 ^= vsriq_n_u32(vshlq_n_u32(a3,18),a3,14);
82
83 diag3 = vextq_u32(diag3,diag3,3);
84 diag2 = vextq_u32(diag2,diag2,2);
85 diag1 = vextq_u32(diag1,diag1,1);
86
87 a0 = diag3 + diag0;
88 diag1 ^= vsriq_n_u32(vshlq_n_u32(a0,7),a0,25);
89 a1 = diag0 + diag1;
90 diag2 ^= vsriq_n_u32(vshlq_n_u32(a1,9),a1,23);
91 a2 = diag1 + diag2;
92 diag3 ^= vsriq_n_u32(vshlq_n_u32(a2,13),a2,19);
93 a3 = diag2 + diag3;
94 diag0 ^= vsriq_n_u32(vshlq_n_u32(a3,18),a3,14);
95
96 diag1 = vextq_u32(diag1,diag1,3);
97 diag2 = vextq_u32(diag2,diag2,2);
98 diag3 = vextq_u32(diag3,diag3,1);
99 }
100
101 x0x5x10x15 = diag0 + start0;
102 x12x1x6x11 = diag1 + start1;
103 x8x13x2x7 = diag2 + start2;
104 x4x9x14x3 = diag3 + start3;
105
106 x0x1x10x11 = vbslq_u32(abab,x0x5x10x15,x12x1x6x11);
107 x12x13x6x7 = vbslq_u32(abab,x12x1x6x11,x8x13x2x7);
108 x8x9x2x3 = vbslq_u32(abab,x8x13x2x7,x4x9x14x3);
109 x4x5x14x15 = vbslq_u32(abab,x4x9x14x3,x0x5x10x15);
110
111 x0x1x2x3 = vcombine_u32(vget_low_u32(x0x1x10x11),vget_high_u32(x8x9x2x3));
112 x4x5x6x7 = vcombine_u32(vget_low_u32(x4x5x14x15),vget_high_u32(x12x13x6x7));
113 x8x9x10x11 = vcombine_u32(vget_low_u32(x8x9x2x3),vget_high_u32(x0x1x10x11));
114 x12x13x14x15 = vcombine_u32(vget_low_u32(x12x13x6x7),vget_high_u32(x4x5x14x15));
115
116 vst1q_u8((uint8_t *) input,(uint8x16_t) x0x1x2x3);
117 vst1q_u8(16 + (uint8_t *) input,(uint8x16_t) x4x5x6x7);
118 vst1q_u8(32 + (uint8_t *) input,(uint8x16_t) x8x9x10x11);
119 vst1q_u8(48 + (uint8_t *) input,(uint8x16_t) x12x13x14x15);
120 }
121