randomx/src/argon2_ref.c

/*
Copyright (c) 2018 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/>.
*/

/* Original code from Argon2 reference source code package used under CC0 Licence
 * https://github.com/P-H-C/phc-winner-argon2
 * Copyright 2015
 * Daniel Dinu, Dmitry Khovratovich, Jean-Philippe Aumasson, and Samuel Neves
*/

#include <stdint.h>
#include <string.h>
#include <stdlib.h>

#include "argon2.h"
#include "argon2_core.h"

#include "blake2/blamka-round-ref.h"
#include "blake2/blake2-impl.h"
#include "blake2/blake2.h"

 /*
  * Function fills a new memory block and optionally XORs the old block over the new one.
  * @next_block must be initialized.
  * @param prev_block Pointer to the previous block
  * @param ref_block Pointer to the reference block
  * @param next_block Pointer to the block to be constructed
  * @param with_xor Whether to XOR into the new block (1) or just overwrite (0)
  * @pre all block pointers must be valid
  */
static void fill_block(const block *prev_block, const block *ref_block,
	block *next_block, int with_xor) {
	block blockR, block_tmp;
	unsigned i;

	copy_block(&blockR, ref_block);
	xor_block(&blockR, prev_block);
	copy_block(&block_tmp, &blockR);
	/* Now blockR = ref_block + prev_block and block_tmp = ref_block + prev_block */
	if (with_xor) {
		/* Saving the next block contents for XOR over: */
		xor_block(&block_tmp, next_block);
		/* Now blockR = ref_block + prev_block and
		   block_tmp = ref_block + prev_block + next_block */
	}

	/* Apply Blake2 on columns of 64-bit words: (0,1,...,15) , then
	   (16,17,..31)... finally (112,113,...127) */
	for (i = 0; i < 8; ++i) {
		BLAKE2_ROUND_NOMSG(
			blockR.v[16 * i], blockR.v[16 * i + 1], blockR.v[16 * i + 2],
			blockR.v[16 * i + 3], blockR.v[16 * i + 4], blockR.v[16 * i + 5],
			blockR.v[16 * i + 6], blockR.v[16 * i + 7], blockR.v[16 * i + 8],
			blockR.v[16 * i + 9], blockR.v[16 * i + 10], blockR.v[16 * i + 11],
			blockR.v[16 * i + 12], blockR.v[16 * i + 13], blockR.v[16 * i + 14],
			blockR.v[16 * i + 15]);
	}

	/* Apply Blake2 on rows of 64-bit words: (0,1,16,17,...112,113), then
	   (2,3,18,19,...,114,115).. finally (14,15,30,31,...,126,127) */
	for (i = 0; i < 8; i++) {
		BLAKE2_ROUND_NOMSG(
			blockR.v[2 * i], blockR.v[2 * i + 1], blockR.v[2 * i + 16],
			blockR.v[2 * i + 17], blockR.v[2 * i + 32], blockR.v[2 * i + 33],
			blockR.v[2 * i + 48], blockR.v[2 * i + 49], blockR.v[2 * i + 64],
			blockR.v[2 * i + 65], blockR.v[2 * i + 80], blockR.v[2 * i + 81],
			blockR.v[2 * i + 96], blockR.v[2 * i + 97], blockR.v[2 * i + 112],
			blockR.v[2 * i + 113]);
	}

	copy_block(next_block, &block_tmp);
	xor_block(next_block, &blockR);
}

static void next_addresses(block *address_block, block *input_block,
	const block *zero_block) {
	input_block->v[6]++;
	fill_block(zero_block, input_block, address_block, 0);
	fill_block(zero_block, address_block, address_block, 0);
}

void fill_segment(const argon2_instance_t *instance,
	argon2_position_t position) {
	block *ref_block = NULL, *curr_block = NULL;
	block address_block, input_block, zero_block;
	uint64_t pseudo_rand, ref_index, ref_lane;
	uint32_t prev_offset, curr_offset;
	uint32_t starting_index;
	uint32_t i;
	int data_independent_addressing;

	if (instance == NULL) {
		return;
	}

	data_independent_addressing =
		(instance->type == Argon2_i) ||
		(instance->type == Argon2_id && (position.pass == 0) &&
		(position.slice < ARGON2_SYNC_POINTS / 2));

	if (data_independent_addressing) {
		init_block_value(&zero_block, 0);
		init_block_value(&input_block, 0);

		input_block.v[0] = position.pass;
		input_block.v[1] = position.lane;
		input_block.v[2] = position.slice;
		input_block.v[3] = instance->memory_blocks;
		input_block.v[4] = instance->passes;
		input_block.v[5] = instance->type;
	}

	starting_index = 0;

	if ((0 == position.pass) && (0 == position.slice)) {
		starting_index = 2; /* we have already generated the first two blocks */

		/* Don't forget to generate the first block of addresses: */
		if (data_independent_addressing) {
			next_addresses(&address_block, &input_block, &zero_block);
		}
	}

	/* Offset of the current block */
	curr_offset = position.lane * instance->lane_length +
		position.slice * instance->segment_length + starting_index;

	if (0 == curr_offset % instance->lane_length) {
		/* Last block in this lane */
		prev_offset = curr_offset + instance->lane_length - 1;
	}
	else {
		/* Previous block */
		prev_offset = curr_offset - 1;
	}

	for (i = starting_index; i < instance->segment_length;
		++i, ++curr_offset, ++prev_offset) {
		/*1.1 Rotating prev_offset if needed */
		if (curr_offset % instance->lane_length == 1) {
			prev_offset = curr_offset - 1;
		}

		/* 1.2 Computing the index of the reference block */
		/* 1.2.1 Taking pseudo-random value from the previous block */
		if (data_independent_addressing) {
			if (i % ARGON2_ADDRESSES_IN_BLOCK == 0) {
				next_addresses(&address_block, &input_block, &zero_block);
			}
			pseudo_rand = address_block.v[i % ARGON2_ADDRESSES_IN_BLOCK];
		}
		else {
			pseudo_rand = instance->memory[prev_offset].v[0];
		}

		/* 1.2.2 Computing the lane of the reference block */
		ref_lane = ((pseudo_rand >> 32)) % instance->lanes;

		if ((position.pass == 0) && (position.slice == 0)) {
			/* Can not reference other lanes yet */
			ref_lane = position.lane;
		}

		/* 1.2.3 Computing the number of possible reference block within the
		 * lane.
		 */
		position.index = i;
		ref_index = index_alpha(instance, &position, pseudo_rand & 0xFFFFFFFF,
			ref_lane == position.lane);

		/* 2 Creating a new block */
		ref_block =
			instance->memory + instance->lane_length * ref_lane + ref_index;
		curr_block = instance->memory + curr_offset;
		if (ARGON2_VERSION_10 == instance->version) {
			/* version 1.2.1 and earlier: overwrite, not XOR */
			fill_block(instance->memory + prev_offset, ref_block, curr_block, 0);
		}
		else {
			if (0 == position.pass) {
				fill_block(instance->memory + prev_offset, ref_block,
					curr_block, 0);
			}
			else {
				fill_block(instance->memory + prev_offset, ref_block,
					curr_block, 1);
			}
		}
	}
}