github.com/ethereum/go-ethereum@v1.16.1/crypto/secp256k1/libsecp256k1/src/precompute_ecmult_gen.c (about)

     1  /*********************************************************************************
     2   * Copyright (c) 2013, 2014, 2015, 2021 Thomas Daede, Cory Fields, Pieter Wuille *
     3   * Distributed under the MIT software license, see the accompanying              *
     4   * file COPYING or https://www.opensource.org/licenses/mit-license.php.          *
     5   *********************************************************************************/
     6  
     7  #include <inttypes.h>
     8  #include <stdio.h>
     9  #include <stdlib.h>
    10  
    11  #include "../include/secp256k1.h"
    12  
    13  #include "assumptions.h"
    14  #include "util.h"
    15  
    16  #include "group.h"
    17  #include "int128_impl.h"
    18  #include "ecmult_gen.h"
    19  #include "ecmult_gen_compute_table_impl.h"
    20  
    21  static const int CONFIGS[][2] = {
    22      {2, 5},
    23      {11, 6},
    24      {43, 6}
    25  };
    26  
    27  static void print_table(FILE* fp, int blocks, int teeth) {
    28      int spacing = CEIL_DIV(256, blocks * teeth);
    29      size_t points = ((size_t)1) << (teeth - 1);
    30      int outer;
    31      size_t inner;
    32  
    33      secp256k1_ge_storage* table = checked_malloc(&default_error_callback, blocks * points * sizeof(secp256k1_ge_storage));
    34      secp256k1_ecmult_gen_compute_table(table, &secp256k1_ge_const_g, blocks, teeth, spacing);
    35  
    36      fprintf(fp, "#elif (COMB_BLOCKS == %d) && (COMB_TEETH == %d) && (COMB_SPACING == %d)\n", blocks, teeth, spacing);
    37      for (outer = 0; outer != blocks; outer++) {
    38          fprintf(fp,"{");
    39          for (inner = 0; inner != points; inner++) {
    40              fprintf(fp, "S(%"PRIx32",%"PRIx32",%"PRIx32",%"PRIx32",%"PRIx32",%"PRIx32",%"PRIx32",%"PRIx32
    41                          ",%"PRIx32",%"PRIx32",%"PRIx32",%"PRIx32",%"PRIx32",%"PRIx32",%"PRIx32",%"PRIx32")",
    42                      SECP256K1_GE_STORAGE_CONST_GET(table[outer * points + inner]));
    43              if (inner != points - 1) {
    44                  fprintf(fp,",\n");
    45              }
    46          }
    47          if (outer != blocks - 1) {
    48              fprintf(fp,"},\n");
    49          } else {
    50              fprintf(fp,"}\n");
    51          }
    52      }
    53      free(table);
    54  }
    55  
    56  int main(int argc, char **argv) {
    57      const char outfile[] = "src/precomputed_ecmult_gen.c";
    58      FILE* fp;
    59      size_t config;
    60      int did_current_config = 0;
    61  
    62      (void)argc;
    63      (void)argv;
    64  
    65      fp = fopen(outfile, "w");
    66      if (fp == NULL) {
    67          fprintf(stderr, "Could not open %s for writing!\n", outfile);
    68          return EXIT_FAILURE;
    69      }
    70  
    71      fprintf(fp, "/* This file was automatically generated by precompute_ecmult_gen. */\n");
    72      fprintf(fp, "/* See ecmult_gen_impl.h for details about the contents of this file. */\n");
    73      fprintf(fp, "#include \"group.h\"\n");
    74      fprintf(fp, "#include \"ecmult_gen.h\"\n");
    75      fprintf(fp, "#include \"precomputed_ecmult_gen.h\"\n");
    76      fprintf(fp, "#ifdef EXHAUSTIVE_TEST_ORDER\n");
    77      fprintf(fp, "#    error Cannot compile precomputed_ecmult_gen.c in exhaustive test mode\n");
    78      fprintf(fp, "#endif /* EXHAUSTIVE_TEST_ORDER */\n");
    79      fprintf(fp, "#define S(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p) SECP256K1_GE_STORAGE_CONST(0x##a##u,0x##b##u,0x##c##u,0x##d##u,0x##e##u,0x##f##u,0x##g##u,0x##h##u,0x##i##u,0x##j##u,0x##k##u,0x##l##u,0x##m##u,0x##n##u,0x##o##u,0x##p##u)\n");
    80  
    81      fprintf(fp, "const secp256k1_ge_storage secp256k1_ecmult_gen_prec_table[COMB_BLOCKS][COMB_POINTS] = {\n");
    82      fprintf(fp, "#if 0\n");
    83      for (config = 0; config < sizeof(CONFIGS) / sizeof(*CONFIGS); ++config) {
    84          print_table(fp, CONFIGS[config][0], CONFIGS[config][1]);
    85          if (CONFIGS[config][0] == COMB_BLOCKS && CONFIGS[config][1] == COMB_TEETH) {
    86              did_current_config = 1;
    87          }
    88      }
    89      if (!did_current_config) {
    90          print_table(fp, COMB_BLOCKS, COMB_TEETH);
    91      }
    92      fprintf(fp, "#else\n");
    93      fprintf(fp, "#    error Configuration mismatch, invalid COMB_* parameters. Try deleting precomputed_ecmult_gen.c before the build.\n");
    94      fprintf(fp, "#endif\n");
    95  
    96      fprintf(fp, "};\n");
    97      fprintf(fp, "#undef S\n");
    98      fclose(fp);
    99  
   100      return EXIT_SUCCESS;
   101  }