config.c

大数运算库miracl。有了miracl这样的函数库

    if (chosen)
    {
        printf("\nDo you want a C-only version of MIRACL (Y/N)?");
        port=answer();
        if (port) fprintf(fp,"#define MR_NOASM\n");
    }
    rounding=0;
    if (double_type)
    {
#ifdef __TURBOC__
        rounding=1;
#endif        
#ifdef _MSC_VER
        rounding=1;
#endif        
#ifdef __GNUC__
        rounding=1;
#endif        
        if (!rounding)
        {
          printf("It will help if rounding control can be exercised on doubles\n");
          printf("Can you implement this in mrarth1.c??  (Y/N)?");
          if (answer()) rounding=1;
        }
        if (rounding) 
        {
            fprintf(fp,"#define MR_FP_ROUNDING\n");
            magic=1.0;
            for (i=0;i<lmant-2;i++) magic*=2.0;
            magic+=2*magic;
            fprintf(fp,"#define MR_MAGIC %lf\n",magic);
        } 
    }

    printf("\nDo you want support for flash arithmetic? (Y/N)?");
    flsh=answer();
    if (flsh)
    { /* calculate size of mantissa in bits */
        eps=1.0;
        for (mant=0;;mant++)
        { /* IMPORTANT TO FOOL OPTIMIZER!!!!!! */
            x=1.0+eps;
            y=1.0;
            if (x==y) break;
            eps/=2.0;
        }
        mant--;
        fprintf(fp,"#define MR_FLASH %d\n",mant);  

        fprintf(fpl,"mrflash.c\n");
        fprintf(fpl,"mrfrnd.c\n");
        fprintf(fpl,"mrdouble.c\n");
        fprintf(fpl,"mrround.c\n");
        fprintf(fpl,"mrbuild.c\n");
        fprintf(fpl,"mrflsh1.c\n");
        fprintf(fpl,"mrpi.c\n");
        fprintf(fpl,"mrflsh2.c\n");
        fprintf(fpl,"mrflsh3.c\n");
        fprintf(fpl,"mrflsh4.c\n");

    }

    printf("Do you want stripped-down version (smaller - no error messages) (Y/N)?");
    stripped=answer();
    if (stripped) fprintf(fp,"#define MR_STRIPPED_DOWN\n");

    printf("Do you want multi-threaded version of MIRACL\n");
    printf("Not recommended for program development - read the manual (Y/N)?");
    threaded=answer();

    if (threaded)
    {
     printf("Do you want generic portable threading support (No C++) (Y/N)?");
     choice=answer();
     if (choice) fprintf(fp,"#define MR_GENERIC_MT\n");
     if (!choice) 
     {
         printf("Do you want multi-threaded support for MS Windows (Y/N)?");
         choice=answer();
         if (choice) fprintf(fp,"#define MR_WINDOWS_MT\n");
     }
     if (!choice)
     {
         printf("Do you want multi-threaded support for Unix (Y/N)?");
         choice=answer();
         if (choice) fprintf(fp,"#define MR_UNIX_MT\n");
 
     }
    }
    printf("Does your development environment support standard screen/keyboard I/O?\n");
    printf("(It doesn't for example in MS Windows, and embedded applications)\n");
    printf("If in doubt, answer Yes (Y/N)?");
    standard=answer();
    if (!standard) fprintf(fp,"#define MR_NO_STANDARD_IO\n");

    printf("Does your development environment support standard file I/O?\n");
    printf("(It doesn't for example in an embedded application)\n");
    printf("If in doubt, answer Yes (Y/N)?");
    standard=answer();
    if (!standard) fprintf(fp,"#define MR_NO_FILE_IO\n");

    if (!chosen && !nofull)
    {
        printf("\n\nDo you for some reason NOT want to use a full-width number base?\n");
        printf("\nYou may not if your processor instruction set does not support\n");
        printf("%d-bit UNSIGNED multiply and divide instructions.\n",utlen);
        printf("If NOT then a full-width number base will be difficult and \n");
        printf("slow to implement, which is a pity, because its normally faster\n"); 
        printf("If for some other reason you don't want to use a full-width\n");
        printf("number base, (no muldvd()/muldvd2()/muldvm() available?), answer Yes\n");
        printf("\nAnswer (Y/N)?");
        nofull=answer();
        if (nofull) 
        {
            printf("\nRemember to use mirsys(...,MAXBASE), or somesuch, in your programs\n");
            printf("as mirsys(...,0); will generate an 'Illegal Number base' error\n");
            fprintf(fp,"#define MR_NOFULLWIDTH\n");
        }
    }
    selected=special=0;
    if (!nofull)
    {
     fprintf(fpl,"mrecgf2m.c\n");

     fprintf(fp,"#define MAXBASE ((mr_small)1<<(MIRACL-1))\n");
     printf("\nDo you wish to use the Karatsuba/Comba/Montgomery method\n");
     printf("for modular arithmetic - as used by exponentiation\n");
     printf("cryptosystems like RSA.\n"); 
     if (port)
     {
      printf("This method may be faster than the standard method when\n");
      printf("using larger moduli, or if your processor has no \n");
      printf("unsigned integer multiply/divide instruction in its\n");
      printf("instruction set. This is true of some popular RISC computers\n");
     }
     else
     {
      printf("This method is probably fastest om most processors which\n");
      printf("which support unsigned mul and a carry flag\n");
      printf("NOTE: your compiler must support in-line assembly,\n");
      printf("and you must be able to supply a suitable .mcs file\n");
      printf("like, for example, ms86.mcs for pentium processors\n");
     }
     printf("\nAnswer (Y/N)?");
     r=answer();
     if (r)
     {
      printf("\nThis method can only be used with moduli whose length in\n");
      printf("bits can be represented as %d*(step size)*2^n, for any value\n",utlen);
      printf("of n. For example if you input a step size of 8, then \n");
      printf("moduli of 256, 512, 1024 bits etc will use this fast code\n");
      if (port)
       printf("In this case case a step size of 4 is probably optimal\n");
      else
      {
       printf("The best step size can be determined by experiment, but\n");
       printf("larger step sizes generate more code. For the Pentium 8 is \n"); 
       printf("optimal. For the Pentium Pro/Pentium II 16 is optimal.\n"); 
       printf("If in doubt, set to 8\n"); 
      }
      step_size=0;
      while (step_size<2 || step_size>16)
      {
          printf("Enter step size = ");
          scanf("%d",&step_size);
          getchar();
      }

      printf("\nTo create the file MRKCM.C you must next execute\n");
      if (port) printf("MEX %d C MRKCM\n",step_size);
      else
      {
       printf("MEX %d <file> MRKCM\n",step_size);
       printf("where <file> is the name of the macro .mcs file (e.g. ms86)\n");
      }

      printf("\nSpecial routines for modular multiplication will now be\n");
      printf("automatically be invoked when, for example, powmod() is called\n");
      printf("\nRemember to use a full-width base in your programs\n");
      printf("by calling mirsys(..,0) or mirsys(..,256) at the start of the program\n");
      
      fprintf(fp,"#define MR_KCM %d\n",step_size);          
      fprintf(fpl,"mrkcm.c\n");
      selected=1;
     }
     else
     {
      printf("\nDo you want to create a Comba fixed size modular\n");
      printf("multiplier, for faster modular multiplication with\n");
      printf("smaller moduli. Can generates a *lot* of code \n");
      printf("Useful particularly for Elliptic Curve cryptosystems.\n");
      printf("\nAnswer (Y/N)?");  
      r=answer();
      if (r)
      {
       step_size=0;
       while (step_size<2 || step_size>32)
       {
          printf("Enter modulus size in bits = ");
          scanf("%d",&nbits);
          getchar();
          step_size=nbits/utlen;
          if ((nbits%utlen)!=0) step_size++;
       }
       printf("Are you willing to implement a \"special\" fast method\n");
       printf("for modular reduction, for a particular modulus\n");
       printf("See mrcomba.tpl. If in any doubt answer No (Y/N)?");
       r=answer();
       if (r) 
       {
         special=1;
         printf("\nYou must first edit the routine comba_redc() in MRCOMBA.TPL");
       }
       printf("\nTo create the file MRCOMBA.C you must next execute\n");
       if (port) printf("MEX %d C MRCOMBA\n",step_size);
       else
       {
        printf("MEX %d <file> MRCOMBA\n",step_size);
        printf("where <file> is the name of the macro .mcs file (e.g. ms86)\n");
       }

       fprintf(fp,"#define MR_COMBA %d\n",step_size);
       if (special) fprintf(fp,"#define MR_SPECIAL\n");
       fprintf(fpl,"mrcomba.c\n");

       printf("\nSpecial routines for modular multiplication will now \n");
       printf("automatically be invoked when, for example, powmod() is called\n");
       printf("\nRemember to use a full-width base in your programs\n");
       printf("by calling mirsys(..,0) or mirsys(,..,256) at the start of the program\n");
       selected=1;
      }

     }
    }
    else
    {
     if (!double_type) fprintf(fp,"#define MAXBASE ((mr_small)1<<(MIRACL-2))\n");
    }

    if (double_type)
    {
     maxbase=0;
#ifdef __TURBOC__ 
     if (!port && !selected)
     {
      printf("\nDoes your computer have a Pentium processor\n");
      printf("and do you wish to exploit its built-in FP coprocessor\n");
      printf("NOTE: this may not be optimal for Pentium Pro or Pentium II\n");
      printf("Supported only for 80x86 processors, and Borland C Compilers\n");
      printf("This is a little experimental - so use with care\n");
      printf("Answer (Y/N)?");
      r=answer();
      if (r) 
      {
          printf("Enter (maximum) modulus size in bits = ");
          scanf("%d",&nbits);
          getchar();
          b=31;
          do {
                  b--;
                  r=64-b-b;
                  s=1.0;
                  for (i=0;i<r;i++) s*=2.0;
                  s*=b;
          } while (s<=2*nbits);
          s=1; for (i=0;i<b;i++) s*=2;
          printf("\nDo you wish to generate variable length looping code, or\n");
          printf("fixed length unrolled code? The former can be used with any\n");
          printf("modulus less than the maximum size specified above. The latter will\n");
          printf("only work with a fixed modulus of that size, but is usually a bit\n");
          printf("faster, although it can generate a *lot* of code for larger moduli.\n"); 

          printf("\nAnswer Yes for looping code(Y/N)?");
          r=answer();
          if (r)
          {
           fprintf(fp,"#define MR_PENTIUM -%d\n",nbits/b+1);

           fprintf(fpl,"mr87v.c\n");

           printf("Make sure to compile and link into your program the module MR87V.C\n");
           }
          else
          {
           fprintf(fp,"#define MR_PENTIUM %d\n",nbits/b+1);
           fprintf(fpl,"mr87f.c\n");
           printf("Make sure to compile and link into your program the module MR87F.C\n");
 
          }
          printf("\nSpecial fast routines for modular multiplication will now be\n");
          printf("automatically be invoked when, for example, powmod() is called\n");
          printf("\nIt is *vital* to use the appropriate number base, so\n");
          printf("you *must* now call mirsys(...,MAXBASE) at the start of your program\n");
          fprintf(fp,"#define MAXBASE %lf\n",s);
          maxbase=1;
      }
     }
#endif
     if (!maxbase)
     {
         s=1.0; 
         for (i=0;i<dmant-1;i++) /* extra bit "spare" so that 2 can be added */
         {
             if (i+i+1>=lmant) break;
             s*=2.0;
         }  
         fprintf(fp,"#define MAXBASE %lf\n",s);
     }
    }
    if (!port)
    {
        if (!dlong) printf("\nYou must now provide an assembly language file mrmuldv.c,\n");
        else printf("\nYou must now provide an assembly or C file mrmuldv.c,\n");
        if (!nofull)
        printf("containing implementations of muldiv(), muldvd(), muldvd2() and muldvm()\n");
        else
        {
            printf("containing an implementation of muldiv()\n");
            if (rounding) printf("..and imuldiv()\n");
        }
        if (!dlong)
            printf("Check mrmuldv.any - an assembly language version may be\n");
        else
            printf("Check mrmuldv.any - a C or assembly language version is\n");
        printf("there already\n");
      
        fprintf(fpl,"mrmuldv.c\n");

    }
    printf("\nA file mirdef.tst has been generated. If you are happy with it,\n");
    printf("rename it to mirdef.h and use for compiling the MIRACL library.\n");

    printf("A file miracl.lst has been generated that includes all the \n");
    printf("files to be included in this build of the MIRACL library.\n");


    fprintf(fpl,"\nCompile the above with -O2 optimization\n");
    if (threaded) 
      fprintf(fpl,"Also use appropriate flag for multi-threaded compilation\n");

    if (!port)
    {
      fprintf(fpl,"Note that mrmuldv.c file may be pure assembly, so may \n");
      fprintf(fpl,"be renamed to mrmuldv.asm or mrmuldv.s, and assembled \n");
      fprintf(fpl,"rather than compiled\n");
    }
    fclose(fp);
    fclose(fpl);

    return 0;
}