git / moonbite-core / src/crypto/chacha20.cpp · raw
// Copyright (c) 2017-2019 The Bitcoin Core developers// Distributed under the MIT software license, see the accompanying// file COPYING or http://www.opensource.org/licenses/mit-license.php.// Based on the public domain implementation 'merged' by D. J. Bernstein// See https://cr.yp.to/chacha.html.#include <crypto/common.h>#include <crypto/chacha20.h>#include <string.h>constexpr static inline uint32_t rotl32(uint32_t v, int c) { return (v << c) | (v >> (32 - c)); }#define QUARTERROUND(a,b,c,d) \ a += b; d = rotl32(d ^ a, 16); \ c += d; b = rotl32(b ^ c, 12); \ a += b; d = rotl32(d ^ a, 8); \ c += d; b = rotl32(b ^ c, 7);static const unsigned char sigma[] = "expand 32-byte k";static const unsigned char tau[] = "expand 16-byte k";void ChaCha20::SetKey(const unsigned char* k, size_t keylen){ const unsigned char *constants; input[4] = ReadLE32(k + 0); input[5] = ReadLE32(k + 4); input[6] = ReadLE32(k + 8); input[7] = ReadLE32(k + 12); if (keylen == 32) { /* recommended */ k += 16; constants = sigma; } else { /* keylen == 16 */ constants = tau; } input[8] = ReadLE32(k + 0); input[9] = ReadLE32(k + 4); input[10] = ReadLE32(k + 8); input[11] = ReadLE32(k + 12); input[0] = ReadLE32(constants + 0); input[1] = ReadLE32(constants + 4); input[2] = ReadLE32(constants + 8); input[3] = ReadLE32(constants + 12); input[12] = 0; input[13] = 0; input[14] = 0; input[15] = 0;}ChaCha20::ChaCha20(){ memset(input, 0, sizeof(input));}ChaCha20::ChaCha20(const unsigned char* k, size_t keylen){ SetKey(k, keylen);}void ChaCha20::SetIV(uint64_t iv){ input[14] = iv; input[15] = iv >> 32;}void ChaCha20::Seek(uint64_t pos){ input[12] = pos; input[13] = pos >> 32;}void ChaCha20::Keystream(unsigned char* c, size_t bytes){ uint32_t x0, x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11, x12, x13, x14, x15; uint32_t j0, j1, j2, j3, j4, j5, j6, j7, j8, j9, j10, j11, j12, j13, j14, j15; unsigned char *ctarget = nullptr; unsigned char tmp[64]; unsigned int i; if (!bytes) return; j0 = input[0]; j1 = input[1]; j2 = input[2]; j3 = input[3]; j4 = input[4]; j5 = input[5]; j6 = input[6]; j7 = input[7]; j8 = input[8]; j9 = input[9]; j10 = input[10]; j11 = input[11]; j12 = input[12]; j13 = input[13]; j14 = input[14]; j15 = input[15]; for (;;) { if (bytes < 64) { ctarget = c; c = tmp; } x0 = j0; x1 = j1; x2 = j2; x3 = j3; x4 = j4; x5 = j5; x6 = j6; x7 = j7; x8 = j8; x9 = j9; x10 = j10; x11 = j11; x12 = j12; x13 = j13; x14 = j14; x15 = j15; for (i = 20;i > 0;i -= 2) { QUARTERROUND( x0, x4, x8,x12) QUARTERROUND( x1, x5, x9,x13) QUARTERROUND( x2, x6,x10,x14) QUARTERROUND( x3, x7,x11,x15) QUARTERROUND( x0, x5,x10,x15) QUARTERROUND( x1, x6,x11,x12) QUARTERROUND( x2, x7, x8,x13) QUARTERROUND( x3, x4, x9,x14) } x0 += j0; x1 += j1; x2 += j2; x3 += j3; x4 += j4; x5 += j5; x6 += j6; x7 += j7; x8 += j8; x9 += j9; x10 += j10; x11 += j11; x12 += j12; x13 += j13; x14 += j14; x15 += j15; ++j12; if (!j12) ++j13; WriteLE32(c + 0, x0); WriteLE32(c + 4, x1); WriteLE32(c + 8, x2); WriteLE32(c + 12, x3); WriteLE32(c + 16, x4); WriteLE32(c + 20, x5); WriteLE32(c + 24, x6); WriteLE32(c + 28, x7); WriteLE32(c + 32, x8); WriteLE32(c + 36, x9); WriteLE32(c + 40, x10); WriteLE32(c + 44, x11); WriteLE32(c + 48, x12); WriteLE32(c + 52, x13); WriteLE32(c + 56, x14); WriteLE32(c + 60, x15); if (bytes <= 64) { if (bytes < 64) { for (i = 0;i < bytes;++i) ctarget[i] = c[i]; } input[12] = j12; input[13] = j13; return; } bytes -= 64; c += 64; }}void ChaCha20::Crypt(const unsigned char* m, unsigned char* c, size_t bytes){ uint32_t x0, x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11, x12, x13, x14, x15; uint32_t j0, j1, j2, j3, j4, j5, j6, j7, j8, j9, j10, j11, j12, j13, j14, j15; unsigned char *ctarget = nullptr; unsigned char tmp[64]; unsigned int i; if (!bytes) return; j0 = input[0]; j1 = input[1]; j2 = input[2]; j3 = input[3]; j4 = input[4]; j5 = input[5]; j6 = input[6]; j7 = input[7]; j8 = input[8]; j9 = input[9]; j10 = input[10]; j11 = input[11]; j12 = input[12]; j13 = input[13]; j14 = input[14]; j15 = input[15]; for (;;) { if (bytes < 64) { // if m has fewer than 64 bytes available, copy m to tmp and // read from tmp instead for (i = 0;i < bytes;++i) tmp[i] = m[i]; m = tmp; ctarget = c; c = tmp; } x0 = j0; x1 = j1; x2 = j2; x3 = j3; x4 = j4; x5 = j5; x6 = j6; x7 = j7; x8 = j8; x9 = j9; x10 = j10; x11 = j11; x12 = j12; x13 = j13; x14 = j14; x15 = j15; for (i = 20;i > 0;i -= 2) { QUARTERROUND( x0, x4, x8,x12) QUARTERROUND( x1, x5, x9,x13) QUARTERROUND( x2, x6,x10,x14) QUARTERROUND( x3, x7,x11,x15) QUARTERROUND( x0, x5,x10,x15) QUARTERROUND( x1, x6,x11,x12) QUARTERROUND( x2, x7, x8,x13) QUARTERROUND( x3, x4, x9,x14) } x0 += j0; x1 += j1; x2 += j2; x3 += j3; x4 += j4; x5 += j5; x6 += j6; x7 += j7; x8 += j8; x9 += j9; x10 += j10; x11 += j11; x12 += j12; x13 += j13; x14 += j14; x15 += j15; x0 ^= ReadLE32(m + 0); x1 ^= ReadLE32(m + 4); x2 ^= ReadLE32(m + 8); x3 ^= ReadLE32(m + 12); x4 ^= ReadLE32(m + 16); x5 ^= ReadLE32(m + 20); x6 ^= ReadLE32(m + 24); x7 ^= ReadLE32(m + 28); x8 ^= ReadLE32(m + 32); x9 ^= ReadLE32(m + 36); x10 ^= ReadLE32(m + 40); x11 ^= ReadLE32(m + 44); x12 ^= ReadLE32(m + 48); x13 ^= ReadLE32(m + 52); x14 ^= ReadLE32(m + 56); x15 ^= ReadLE32(m + 60); ++j12; if (!j12) ++j13; WriteLE32(c + 0, x0); WriteLE32(c + 4, x1); WriteLE32(c + 8, x2); WriteLE32(c + 12, x3); WriteLE32(c + 16, x4); WriteLE32(c + 20, x5); WriteLE32(c + 24, x6); WriteLE32(c + 28, x7); WriteLE32(c + 32, x8); WriteLE32(c + 36, x9); WriteLE32(c + 40, x10); WriteLE32(c + 44, x11); WriteLE32(c + 48, x12); WriteLE32(c + 52, x13); WriteLE32(c + 56, x14); WriteLE32(c + 60, x15); if (bytes <= 64) { if (bytes < 64) { for (i = 0;i < bytes;++i) ctarget[i] = c[i]; } input[12] = j12; input[13] = j13; return; } bytes -= 64; c += 64; m += 64; }}