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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/* This implementation is by Ted Krovetz and was submitted to SUPERCOP and
* marked as public domain. It was been altered to allow for non-aligned inputs
* and to allow the block counter to be passed in specifically. */
#include <string.h>
#include "chacha20.h"
#include "blapii.h"
#ifndef CHACHA_RNDS
#define CHACHA_RNDS 20 /* 8 (high speed), 20 (conservative), 12 (middle) */
#endif
/* Architecture-neutral way to specify 16-byte vector of ints */
typedef unsigned vec __attribute__((vector_size(16)));
/* This implementation is designed for Neon, SSE and AltiVec machines. The
* following specify how to do certain vector operations efficiently on
* each architecture, using intrinsics.
* This implementation supports parallel processing of multiple blocks,
* including potentially using general-purpose registers.
*/
#if __ARM_NEON__
#include <arm_neon.h>
#define GPR_TOO 1
#define VBPI 2
#define ONE (vec) vsetq_lane_u32(1, vdupq_n_u32(0), 0)
#define LOAD(m) (vec)(*((vec *)(m)))
#define STORE(m, r) (*((vec *)(m))) = (r)
#define ROTV1(x) (vec) vextq_u32((uint32x4_t)x, (uint32x4_t)x, 1)
#define ROTV2(x) (vec) vextq_u32((uint32x4_t)x, (uint32x4_t)x, 2)
#define ROTV3(x) (vec) vextq_u32((uint32x4_t)x, (uint32x4_t)x, 3)
#define ROTW16(x) (vec) vrev32q_u16((uint16x8_t)x)
#if __clang__
#define ROTW7(x) (x << ((vec){ 7, 7, 7, 7 })) ^ (x >> ((vec){ 25, 25, 25, 25 }))
#define ROTW8(x) (x << ((vec){ 8, 8, 8, 8 })) ^ (x >> ((vec){ 24, 24, 24, 24 }))
#define ROTW12(x) (x << ((vec){ 12, 12, 12, 12 })) ^ (x >> ((vec){ 20, 20, 20, 20 }))
#else
#define ROTW7(x) (vec) vsriq_n_u32(vshlq_n_u32((uint32x4_t)x, 7), (uint32x4_t)x, 25)
#define ROTW8(x) (vec) vsriq_n_u32(vshlq_n_u32((uint32x4_t)x, 8), (uint32x4_t)x, 24)
#define ROTW12(x) (vec) vsriq_n_u32(vshlq_n_u32((uint32x4_t)x, 12), (uint32x4_t)x, 20)
#endif
#elif __SSE2__
#include <emmintrin.h>
#define GPR_TOO 0
#if __clang__
#define VBPI 4
#else
#define VBPI 3
#endif
#define ONE (vec) _mm_set_epi32(0, 0, 0, 1)
#define LOAD(m) (vec) _mm_loadu_si128((__m128i *)(m))
#define STORE(m, r) _mm_storeu_si128((__m128i *)(m), (__m128i)(r))
#define ROTV1(x) (vec) _mm_shuffle_epi32((__m128i)x, _MM_SHUFFLE(0, 3, 2, 1))
#define ROTV2(x) (vec) _mm_shuffle_epi32((__m128i)x, _MM_SHUFFLE(1, 0, 3, 2))
#define ROTV3(x) (vec) _mm_shuffle_epi32((__m128i)x, _MM_SHUFFLE(2, 1, 0, 3))
#define ROTW7(x) (vec)(_mm_slli_epi32((__m128i)x, 7) ^ _mm_srli_epi32((__m128i)x, 25))
#define ROTW12(x) (vec)(_mm_slli_epi32((__m128i)x, 12) ^ _mm_srli_epi32((__m128i)x, 20))
#if __SSSE3__
#include <tmmintrin.h>
#define ROTW8(x) (vec) _mm_shuffle_epi8((__m128i)x, _mm_set_epi8(14, 13, 12, 15, 10, 9, 8, 11, 6, 5, 4, 7, 2, 1, 0, 3))
#define ROTW16(x) (vec) _mm_shuffle_epi8((__m128i)x, _mm_set_epi8(13, 12, 15, 14, 9, 8, 11, 10, 5, 4, 7, 6, 1, 0, 3, 2))
#else
#define ROTW8(x) (vec)(_mm_slli_epi32((__m128i)x, 8) ^ _mm_srli_epi32((__m128i)x, 24))
#define ROTW16(x) (vec)(_mm_slli_epi32((__m128i)x, 16) ^ _mm_srli_epi32((__m128i)x, 16))
#endif
#else
#error-- Implementation supports only machines with neon or SSE2
#endif
#ifndef REVV_BE
#define REVV_BE(x) (x)
#endif
#ifndef REVW_BE
#define REVW_BE(x) (x)
#endif
#define BPI (VBPI + GPR_TOO) /* Blocks computed per loop iteration */
#define DQROUND_VECTORS(a, b, c, d) \
a += b; \
d ^= a; \
d = ROTW16(d); \
c += d; \
b ^= c; \
b = ROTW12(b); \
a += b; \
d ^= a; \
d = ROTW8(d); \
c += d; \
b ^= c; \
b = ROTW7(b); \
b = ROTV1(b); \
c = ROTV2(c); \
d = ROTV3(d); \
a += b; \
d ^= a; \
d = ROTW16(d); \
c += d; \
b ^= c; \
b = ROTW12(b); \
a += b; \
d ^= a; \
d = ROTW8(d); \
c += d; \
b ^= c; \
b = ROTW7(b); \
b = ROTV3(b); \
c = ROTV2(c); \
d = ROTV1(d);
#define QROUND_WORDS(a, b, c, d) \
a = a + b; \
d ^= a; \
d = d << 16 | d >> 16; \
c = c + d; \
b ^= c; \
b = b << 12 | b >> 20; \
a = a + b; \
d ^= a; \
d = d << 8 | d >> 24; \
c = c + d; \
b ^= c; \
b = b << 7 | b >> 25;
#define WRITE_XOR(in, op, d, v0, v1, v2, v3) \
STORE(op + d + 0, LOAD(in + d + 0) ^ REVV_BE(v0)); \
STORE(op + d + 4, LOAD(in + d + 4) ^ REVV_BE(v1)); \
STORE(op + d + 8, LOAD(in + d + 8) ^ REVV_BE(v2)); \
STORE(op + d + 12, LOAD(in + d + 12) ^ REVV_BE(v3));
void NO_SANITIZE_ALIGNMENT
ChaCha20XOR(unsigned char *out, const unsigned char *in, unsigned int inlen,
const unsigned char key[32], const unsigned char nonce[12],
uint32_t counter)
{
unsigned iters, i, *op = (unsigned *)out, *ip = (unsigned *)in, *kp;
#if defined(__ARM_NEON__)
unsigned *np;
#endif
vec s0, s1, s2, s3;
#if !defined(__ARM_NEON__) && !defined(__SSE2__)
__attribute__((aligned(16))) unsigned key[8], nonce[4];
#endif
__attribute__((aligned(16))) unsigned chacha_const[] =
{ 0x61707865, 0x3320646E, 0x79622D32, 0x6B206574 };
#if defined(__ARM_NEON__) || defined(__SSE2__)
kp = (unsigned *)key;
#else
((vec *)key)[0] = REVV_BE(((vec *)key)[0]);
((vec *)key)[1] = REVV_BE(((vec *)key)[1]);
((unsigned *)nonce)[0] = REVW_BE(((unsigned *)nonce)[0]);
((unsigned *)nonce)[1] = REVW_BE(((unsigned *)nonce)[1]);
((unsigned *)nonce)[2] = REVW_BE(((unsigned *)nonce)[2]);
((unsigned *)nonce)[3] = REVW_BE(((unsigned *)nonce)[3]);
kp = (unsigned *)key;
np = (unsigned *)nonce;
#endif
#if defined(__ARM_NEON__)
np = (unsigned *)nonce;
#endif
s0 = LOAD(chacha_const);
s1 = LOAD(&((vec *)kp)[0]);
s2 = LOAD(&((vec *)kp)[1]);
s3 = (vec){
counter,
((uint32_t *)nonce)[0],
((uint32_t *)nonce)[1],
((uint32_t *)nonce)[2]
};
for (iters = 0; iters < inlen / (BPI * 64); iters++) {
#if GPR_TOO
register unsigned x0, x1, x2, x3, x4, x5, x6, x7, x8,
x9, x10, x11, x12, x13, x14, x15;
#endif
#if VBPI > 2
vec v8, v9, v10, v11;
#endif
#if VBPI > 3
vec v12, v13, v14, v15;
#endif
vec v0, v1, v2, v3, v4, v5, v6, v7;
v4 = v0 = s0;
v5 = v1 = s1;
v6 = v2 = s2;
v3 = s3;
v7 = v3 + ONE;
#if VBPI > 2
v8 = v4;
v9 = v5;
v10 = v6;
v11 = v7 + ONE;
#endif
#if VBPI > 3
v12 = v8;
v13 = v9;
v14 = v10;
v15 = v11 + ONE;
#endif
#if GPR_TOO
x0 = chacha_const[0];
x1 = chacha_const[1];
x2 = chacha_const[2];
x3 = chacha_const[3];
x4 = kp[0];
x5 = kp[1];
x6 = kp[2];
x7 = kp[3];
x8 = kp[4];
x9 = kp[5];
x10 = kp[6];
x11 = kp[7];
x12 = counter + BPI * iters + (BPI - 1);
x13 = np[0];
x14 = np[1];
x15 = np[2];
#endif
for (i = CHACHA_RNDS / 2; i; i--) {
DQROUND_VECTORS(v0, v1, v2, v3)
DQROUND_VECTORS(v4, v5, v6, v7)
#if VBPI > 2
DQROUND_VECTORS(v8, v9, v10, v11)
#endif
#if VBPI > 3
DQROUND_VECTORS(v12, v13, v14, v15)
#endif
#if GPR_TOO
QROUND_WORDS(x0, x4, x8, x12)
QROUND_WORDS(x1, x5, x9, x13)
QROUND_WORDS(x2, x6, x10, x14)
QROUND_WORDS(x3, x7, x11, x15)
QROUND_WORDS(x0, x5, x10, x15)
QROUND_WORDS(x1, x6, x11, x12)
QROUND_WORDS(x2, x7, x8, x13)
QROUND_WORDS(x3, x4, x9, x14)
#endif
}
WRITE_XOR(ip, op, 0, v0 + s0, v1 + s1, v2 + s2, v3 + s3)
s3 += ONE;
WRITE_XOR(ip, op, 16, v4 + s0, v5 + s1, v6 + s2, v7 + s3)
s3 += ONE;
#if VBPI > 2
WRITE_XOR(ip, op, 32, v8 + s0, v9 + s1, v10 + s2, v11 + s3)
s3 += ONE;
#endif
#if VBPI > 3
WRITE_XOR(ip, op, 48, v12 + s0, v13 + s1, v14 + s2, v15 + s3)
s3 += ONE;
#endif
ip += VBPI * 16;
op += VBPI * 16;
#if GPR_TOO
op[0] = REVW_BE(REVW_BE(ip[0]) ^ (x0 + chacha_const[0]));
op[1] = REVW_BE(REVW_BE(ip[1]) ^ (x1 + chacha_const[1]));
op[2] = REVW_BE(REVW_BE(ip[2]) ^ (x2 + chacha_const[2]));
op[3] = REVW_BE(REVW_BE(ip[3]) ^ (x3 + chacha_const[3]));
op[4] = REVW_BE(REVW_BE(ip[4]) ^ (x4 + kp[0]));
op[5] = REVW_BE(REVW_BE(ip[5]) ^ (x5 + kp[1]));
op[6] = REVW_BE(REVW_BE(ip[6]) ^ (x6 + kp[2]));
op[7] = REVW_BE(REVW_BE(ip[7]) ^ (x7 + kp[3]));
op[8] = REVW_BE(REVW_BE(ip[8]) ^ (x8 + kp[4]));
op[9] = REVW_BE(REVW_BE(ip[9]) ^ (x9 + kp[5]));
op[10] = REVW_BE(REVW_BE(ip[10]) ^ (x10 + kp[6]));
op[11] = REVW_BE(REVW_BE(ip[11]) ^ (x11 + kp[7]));
op[12] = REVW_BE(REVW_BE(ip[12]) ^ (x12 + counter + BPI * iters + (BPI - 1)));
op[13] = REVW_BE(REVW_BE(ip[13]) ^ (x13 + np[0]));
op[14] = REVW_BE(REVW_BE(ip[14]) ^ (x14 + np[1]));
op[15] = REVW_BE(REVW_BE(ip[15]) ^ (x15 + np[2]));
s3 += ONE;
ip += 16;
op += 16;
#endif
}
for (iters = inlen % (BPI * 64) / 64; iters != 0; iters--) {
vec v0 = s0, v1 = s1, v2 = s2, v3 = s3;
for (i = CHACHA_RNDS / 2; i; i--) {
DQROUND_VECTORS(v0, v1, v2, v3);
}
WRITE_XOR(ip, op, 0, v0 + s0, v1 + s1, v2 + s2, v3 + s3)
s3 += ONE;
ip += 16;
op += 16;
}
inlen = inlen % 64;
if (inlen) {
__attribute__((aligned(16))) vec buf[4];
vec v0, v1, v2, v3;
v0 = s0;
v1 = s1;
v2 = s2;
v3 = s3;
for (i = CHACHA_RNDS / 2; i; i--) {
DQROUND_VECTORS(v0, v1, v2, v3);
}
if (inlen >= 16) {
STORE(op + 0, LOAD(ip + 0) ^ REVV_BE(v0 + s0));
if (inlen >= 32) {
STORE(op + 4, LOAD(ip + 4) ^ REVV_BE(v1 + s1));
if (inlen >= 48) {
STORE(op + 8, LOAD(ip + 8) ^ REVV_BE(v2 + s2));
buf[3] = REVV_BE(v3 + s3);
} else {
buf[2] = REVV_BE(v2 + s2);
}
} else {
buf[1] = REVV_BE(v1 + s1);
}
} else {
buf[0] = REVV_BE(v0 + s0);
}
for (i = inlen & ~15; i < inlen; i++) {
((char *)op)[i] = ((char *)ip)[i] ^ ((char *)buf)[i];
}
}
}
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