text: #include "libc/log/libfatal.internal.h"
  #include "third_party/argon2/argon2.h"
  #include "third_party/argon2/blake2-impl.h"
  #include "third_party/argon2/blake2.h"
  #include "third_party/argon2/blamka-round-ref.h"
  #include "third_party/argon2/core.h"
  /* clang-format off */
  
  /*
   * Argon2 reference source code package - reference C implementations
   *
   * Copyright 2015
   * Daniel Dinu, Dmitry Khovratovich, Jean-Philippe Aumasson, and Samuel Neves
   *
   * You may use this work under the terms of a Creative Commons CC0 1.0
   * License/Waiver or the Apache Public License 2.0, at your option. The terms of
   * these licenses can be found at:
   *
   * - CC0 1.0 Universal : https://creativecommons.org/publicdomain/zero/1.0
   * - Apache 2.0        : https://www.apache.org/licenses/LICENSE-2.0
   *
   * You should have received a copy of both of these licenses along with this
   * software. If not, they may be obtained at the above URLs.
   */
  
  /*
   * i 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 optimizespeed void fill_block(const block *prev_block,
                                       const block *ref_block,
                                       block *next_block,
                                       int with_xor) {
      block blockR, block_tmp;
      unsigned i;
  
      if (with_xor) {
          for (i = 0; i < ARGON2_QWORDS_IN_BLOCK; ++i) {
              block_tmp.v[i] = (blockR.v[i] = prev_block->v[i] ^ ref_block->v[i]) ^ next_block->v[i];
          }
      } else {
          for (i = 0; i < ARGON2_QWORDS_IN_BLOCK; ++i) {
              block_tmp.v[i] = blockR.v[i] = prev_block->v[i] ^ ref_block->v[i];
          }
      }
  
      /* 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]);
      }
  
      for (i = 0; i < ARGON2_QWORDS_IN_BLOCK; ++i) {
          next_block->v[i] = block_tmp.v[i] ^ blockR.v[i];
      }
  }
  
  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);
              }
          }
      }
  }
  