/*
Copyright (c) 2019 tevador

This file is part of RandomX.

RandomX is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

RandomX is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with RandomX.  If not, see<http://www.gnu.org/licenses/>.
*/

#include "softAes.h"

/*
	Calculate a 512-bit hash of 'input' using 4 lanes of AES.
	The input is treated as a set of round keys for the encryption
	of the initial state.

	'inputSize' must be a multiple of 64.

	For a 2 MiB input, this has the same security as 32768-round
	AES encryption.

	Hashing throughput: >20 GiB/s per CPU core with hardware AES
*/
template<bool softAes>
void hashAes1Rx4(const void *input, size_t inputSize, void *hash) {
	const uint8_t* inptr = (uint8_t*)input;
	const uint8_t* inputEnd = inptr + inputSize;

	__m128i state0, state1, state2, state3;
	__m128i in0, in1, in2, in3;

	//intial state
	state0 = _mm_set_epi32(0x9d04b0ae, 0x59943385, 0x30ac8d93, 0x3fe49f5d);
	state1 = _mm_set_epi32(0x8a39ebf1, 0xddc10935, 0xa724ecd3, 0x7b0c6064);
	state2 = _mm_set_epi32(0x7ec70420, 0xdf01edda, 0x7c12ecf7, 0xfb5382e3);
	state3 = _mm_set_epi32(0x94a9d201, 0x5082d1c8, 0xb2e74109, 0x7728b705);

	//process 64 bytes at a time in 4 lanes
	while (inptr < inputEnd) {
		in0 = _mm_load_si128((__m128i*)inptr + 0);
		in1 = _mm_load_si128((__m128i*)inptr + 1);
		in2 = _mm_load_si128((__m128i*)inptr + 2);
		in3 = _mm_load_si128((__m128i*)inptr + 3);

		state0 = aesenc<softAes>(state0, in0);
		state1 = aesdec<softAes>(state1, in1);
		state2 = aesenc<softAes>(state2, in2);
		state3 = aesdec<softAes>(state3, in3);

		inptr += 64;
	}

	//two extra rounds to achieve full diffusion
	__m128i xkey0 = _mm_set_epi32(0x4ff637c5, 0x053bd705, 0x8231a744, 0xc3767b17);
	__m128i xkey1 = _mm_set_epi32(0x6594a1a6, 0xa8879d58, 0xb01da200, 0x8a8fae2e);

	state0 = aesenc<softAes>(state0, xkey0);
	state1 = aesdec<softAes>(state1, xkey0);
	state2 = aesenc<softAes>(state2, xkey0);
	state3 = aesdec<softAes>(state3, xkey0);

	state0 = aesenc<softAes>(state0, xkey1);
	state1 = aesdec<softAes>(state1, xkey1);
	state2 = aesenc<softAes>(state2, xkey1);
	state3 = aesdec<softAes>(state3, xkey1);

	//output hash
	_mm_store_si128((__m128i*)hash + 0, state0);
	_mm_store_si128((__m128i*)hash + 1, state1);
	_mm_store_si128((__m128i*)hash + 2, state2);
	_mm_store_si128((__m128i*)hash + 3, state3);
}

template void hashAes1Rx4<false>(const void *input, size_t inputSize, void *hash);
template void hashAes1Rx4<true>(const void *input, size_t inputSize, void *hash);

/*
	Fill 'buffer' with pseudorandom data based on 512-bit 'state'.
	The state is encrypted using a single AES round per 16 bytes of output
	in 4 lanes.

	'outputSize' must be a multiple of 64.

	The modified state is written back to 'state' to allow multiple
	calls to this function.
*/
template<bool softAes>
void fillAes1Rx4(void *state, size_t outputSize, void *buffer) {
	const uint8_t* outptr = (uint8_t*)buffer;
	const uint8_t* outputEnd = outptr + outputSize;

	__m128i state0, state1, state2, state3;
	__m128i key0, key1, key2, key3;

	key0 = _mm_set_epi32(0x9274f206, 0x79498d2f, 0x7d2de6ab, 0x67a04d26);
	key1 = _mm_set_epi32(0xe1f7af05, 0x2a3a6f1d, 0x86658a15, 0x4f719812);
	key2 = _mm_set_epi32(0xd1b1f791, 0x9e2ec914, 0x14c77bce, 0xba90750e);
	key3 = _mm_set_epi32(0x179d0fd9, 0x6e57883c, 0xa53bbe4f, 0xaa07621f);

	state0 = _mm_load_si128((__m128i*)state + 0);
	state1 = _mm_load_si128((__m128i*)state + 1);
	state2 = _mm_load_si128((__m128i*)state + 2);
	state3 = _mm_load_si128((__m128i*)state + 3);

	while (outptr < outputEnd) {
		state0 = aesdec<softAes>(state0, key0);
		state1 = aesenc<softAes>(state1, key1);
		state2 = aesdec<softAes>(state2, key2);
		state3 = aesenc<softAes>(state3, key3);

		_mm_store_si128((__m128i*)outptr + 0, state0);
		_mm_store_si128((__m128i*)outptr + 1, state1);
		_mm_store_si128((__m128i*)outptr + 2, state2);
		_mm_store_si128((__m128i*)outptr + 3, state3);

		outptr += 64;
	}

	_mm_store_si128((__m128i*)state + 0, state0);
	_mm_store_si128((__m128i*)state + 1, state1);
	_mm_store_si128((__m128i*)state + 2, state2);
	_mm_store_si128((__m128i*)state + 3, state3);
}

template void fillAes1Rx4<true>(void *state, size_t outputSize, void *buffer);
template void fillAes1Rx4<false>(void *state, size_t outputSize, void *buffer);