| /* Copyright (c) 2014, Google Inc. |
| * |
| * Permission to use, copy, modify, and/or distribute this software for any |
| * purpose with or without fee is hereby granted, provided that the above |
| * copyright notice and this permission notice appear in all copies. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
| * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
| * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY |
| * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
| * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION |
| * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN |
| * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ |
| |
| /* Adapted from the public domain, estream code by D. Bernstein. */ |
| |
| #include <openssl/chacha.h> |
| |
| #include <openssl/cpu.h> |
| |
| #if defined(OPENSSL_WINDOWS) || (!defined(OPENSSL_X86_64) && !defined(OPENSSL_X86)) || !defined(__SSE2__) |
| |
| /* sigma contains the ChaCha constants, which happen to be an ASCII string. */ |
| static const char sigma[16] = "expand 32-byte k"; |
| |
| #define ROTATE(v, n) (((v) << (n)) | ((v) >> (32 - (n)))) |
| #define XOR(v, w) ((v) ^ (w)) |
| #define PLUS(x, y) ((x) + (y)) |
| #define PLUSONE(v) (PLUS((v), 1)) |
| |
| #define U32TO8_LITTLE(p, v) \ |
| { \ |
| (p)[0] = (v >> 0) & 0xff; \ |
| (p)[1] = (v >> 8) & 0xff; \ |
| (p)[2] = (v >> 16) & 0xff; \ |
| (p)[3] = (v >> 24) & 0xff; \ |
| } |
| |
| #define U8TO32_LITTLE(p) \ |
| (((uint32_t)((p)[0])) | ((uint32_t)((p)[1]) << 8) | \ |
| ((uint32_t)((p)[2]) << 16) | ((uint32_t)((p)[3]) << 24)) |
| |
| /* QUARTERROUND updates a, b, c, d with a ChaCha "quarter" round. */ |
| #define QUARTERROUND(a,b,c,d) \ |
| x[a] = PLUS(x[a],x[b]); x[d] = ROTATE(XOR(x[d],x[a]),16); \ |
| x[c] = PLUS(x[c],x[d]); x[b] = ROTATE(XOR(x[b],x[c]),12); \ |
| x[a] = PLUS(x[a],x[b]); x[d] = ROTATE(XOR(x[d],x[a]), 8); \ |
| x[c] = PLUS(x[c],x[d]); x[b] = ROTATE(XOR(x[b],x[c]), 7); |
| |
| #if defined(OPENSSL_ARM) |
| /* Defined in chacha_vec.c */ |
| void CRYPTO_chacha_20_neon(uint8_t *out, const uint8_t *in, size_t in_len, |
| const uint8_t key[32], const uint8_t nonce[8], |
| size_t counter); |
| #endif |
| |
| /* chacha_core performs |num_rounds| rounds of ChaCha20 on the input words in |
| * |input| and writes the 64 output bytes to |output|. */ |
| static void chacha_core(uint8_t output[64], const uint32_t input[16]) { |
| uint32_t x[16]; |
| int i; |
| |
| memcpy(x, input, sizeof(uint32_t) * 16); |
| for (i = 20; i > 0; i -= 2) { |
| QUARTERROUND(0, 4, 8, 12) |
| QUARTERROUND(1, 5, 9, 13) |
| QUARTERROUND(2, 6, 10, 14) |
| QUARTERROUND(3, 7, 11, 15) |
| QUARTERROUND(0, 5, 10, 15) |
| QUARTERROUND(1, 6, 11, 12) |
| QUARTERROUND(2, 7, 8, 13) |
| QUARTERROUND(3, 4, 9, 14) |
| } |
| |
| for (i = 0; i < 16; ++i) { |
| x[i] = PLUS(x[i], input[i]); |
| } |
| for (i = 0; i < 16; ++i) { |
| U32TO8_LITTLE(output + 4 * i, x[i]); |
| } |
| } |
| |
| void CRYPTO_chacha_20(uint8_t *out, const uint8_t *in, size_t in_len, |
| const uint8_t key[32], const uint8_t nonce[8], |
| size_t counter) { |
| uint32_t input[16]; |
| uint8_t buf[64]; |
| size_t todo, i; |
| |
| #if defined(OPENSSL_ARM) |
| if (CRYPTO_is_NEON_capable() && ((intptr_t)in & 15) == 0 && |
| ((intptr_t)out & 15) == 0) { |
| CRYPTO_chacha_20_neon(out, in, in_len, key, nonce, counter); |
| return; |
| } |
| #endif |
| |
| input[0] = U8TO32_LITTLE(sigma + 0); |
| input[1] = U8TO32_LITTLE(sigma + 4); |
| input[2] = U8TO32_LITTLE(sigma + 8); |
| input[3] = U8TO32_LITTLE(sigma + 12); |
| |
| input[4] = U8TO32_LITTLE(key + 0); |
| input[5] = U8TO32_LITTLE(key + 4); |
| input[6] = U8TO32_LITTLE(key + 8); |
| input[7] = U8TO32_LITTLE(key + 12); |
| |
| input[8] = U8TO32_LITTLE(key + 16); |
| input[9] = U8TO32_LITTLE(key + 20); |
| input[10] = U8TO32_LITTLE(key + 24); |
| input[11] = U8TO32_LITTLE(key + 28); |
| |
| input[12] = counter; |
| input[13] = ((uint64_t)counter) >> 32; |
| input[14] = U8TO32_LITTLE(nonce + 0); |
| input[15] = U8TO32_LITTLE(nonce + 4); |
| |
| while (in_len > 0) { |
| todo = sizeof(buf); |
| if (in_len < todo) { |
| todo = in_len; |
| } |
| |
| chacha_core(buf, input); |
| for (i = 0; i < todo; i++) { |
| out[i] = in[i] ^ buf[i]; |
| } |
| |
| out += todo; |
| in += todo; |
| in_len -= todo; |
| |
| input[12]++; |
| if (input[12] == 0) { |
| input[13]++; |
| } |
| } |
| } |
| |
| #endif /* OPENSSL_WINDOWS || !OPENSSL_X86_64 && !OPENSSL_X86 || !__SSE2__ */ |