text: /*
   * Argon2 source code package
   *
   * Written by Daniel Dinu and Dmitry Khovratovich, 2015
   *
   * This work is licensed under a Creative Commons CC0 1.0 License/Waiver.
   *
   * You should have received a copy of the CC0 Public Domain Dedication along
   * with
   * this software. If not, see
   * <http://creativecommons.org/publicdomain/zero/1.0/>.
   */
  
  #include <stdint.h>
  #include <stdlib.h>
  #include <string.h>
  
  #include "argon2.h"
  #include "argon2-core.h"
  #include "argon2-impl.h"
  #include "blamka-round-ref.h"
  
  static void fill_block(const block *prev_block, const block *ref_block,
                         block *next_block) {
      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 bloc_tmp = ref_block + prev_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 fill_block_with_xor(const block *prev_block, const block *ref_block,
                                  block *next_block) {
      block blockR, block_tmp;
      unsigned i;
  
      copy_block(&blockR, ref_block);
      xor_block(&blockR, prev_block);
      copy_block(&block_tmp, &blockR);
      xor_block(&block_tmp, next_block); /* Saving the next block contents for XOR over */
      /* Now blockR = ref_block + prev_block and bloc_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);
  }
  
  /*
   * Generate pseudo-random values to reference blocks in the segment and puts
   * them into the array
   * @param instance Pointer to the current instance
   * @param position Pointer to the current position
   * @param pseudo_rands Pointer to the array of 64-bit values
   * @pre pseudo_rands must point to @a instance->segment_length allocated values
   */
  static void generate_addresses(const argon2_instance_t *instance,
                                 const argon2_position_t *position,
                                 uint64_t *pseudo_rands) {
      block zero_block, input_block, address_block, tmp_block;
      uint32_t i;
  
      init_block_value(&zero_block, 0);
      init_block_value(&input_block, 0);
  
      if (instance != NULL && position != NULL) {
          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;
  
          for (i = 0; i < instance->segment_length; ++i) {
              if (i % ARGON2_ADDRESSES_IN_BLOCK == 0) {
                  input_block.v[6]++;
                  init_block_value(&tmp_block, 0);
                  init_block_value(&address_block, 0);
                  fill_block_with_xor(&zero_block, &input_block, &tmp_block);
                  fill_block_with_xor(&zero_block, &tmp_block, &address_block);
              }
  
              pseudo_rands[i] = address_block.v[i % ARGON2_ADDRESSES_IN_BLOCK];
          }
      }
  }
  
  int fill_segment_ref(const argon2_instance_t *instance,
                       argon2_position_t position) {
      block *ref_block = NULL, *curr_block = NULL;
      uint64_t pseudo_rand, ref_index, ref_lane;
      uint32_t prev_offset, curr_offset;
      uint32_t starting_index;
      uint32_t i;
      const int data_independent_addressing = 1; /* instance->type == Argon2_i */
      /* Pseudo-random values that determine the reference block position */
      uint64_t *pseudo_rands = NULL;
  
      if (instance == NULL) {
          return ARGON2_OK;
      }
  
      pseudo_rands =
          (uint64_t *)malloc(sizeof(uint64_t) * (instance->segment_length));
  
      if (pseudo_rands == NULL) {
          return ARGON2_MEMORY_ALLOCATION_ERROR;
      }
  
      if (data_independent_addressing) {
          generate_addresses(instance, &position, pseudo_rands);
      }
  
      starting_index = 0;
  
      if ((0 == position.pass) && (0 == position.slice)) {
          starting_index = 2; /* we have already generated the first two blocks */
      }
  
      /* 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) {
  #pragma warning(push)
  #pragma warning(disable: 6385)
              pseudo_rand = pseudo_rands[i];
  #pragma warning(pop)
          } else {
              pseudo_rand = instance->region->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->region->memory + instance->lane_length * ref_lane + ref_index;
          curr_block = instance->region->memory + curr_offset;
          if (position.pass != 0) {
              fill_block_with_xor(instance->region->memory + prev_offset, ref_block, curr_block);
          } else {
              fill_block(instance->region->memory + prev_offset, ref_block, curr_block);
          }
      }
  
      free(pseudo_rands);
  
      return ARGON2_OK;
  }
  
  