/* @(#)root/srputils:$Id$ */
/*
 * Copyright (c) 1997-1999  The Stanford SRP Authentication Project
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
 * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
 *
 * IN NO EVENT SHALL STANFORD BE LIABLE FOR ANY SPECIAL, INCIDENTAL,
 * INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND, OR ANY DAMAGES WHATSOEVER
 * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER OR NOT ADVISED OF
 * THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF LIABILITY, ARISING OUT
 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 * In addition, the following conditions apply:
 *
 * 1. Any software that incorporates the SRP authentication technology
 *    must display the following acknowlegment:
 *    "This product uses the 'Secure Remote Password' cryptographic
 *     authentication system developed by Tom Wu (tjw@CS.Stanford.EDU)."
 *
 * 2. Any software that incorporates all or part of the SRP distribution
 *    itself must also display the following acknowledgment:
 *    "This product includes software developed by Tom Wu and Eugene
 *     Jhong for the SRP Distribution (http://srp.stanford.edu/srp/)."
 *
 * 3. Redistributions in source or binary form must retain an intact copy
 *    of this copyright notice and list of conditions.
 */

#include <unistd.h>             /* close getlogin */
#include <stdlib.h>             /* atexit exit */
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>

#include "t_pwd.h"

#define SROOTDCONF ".srootdpass.conf"

#define MIN_BASIS_BITS 257
#define BASIS_BITS 2048

extern int optind;
extern char *optarg;

struct pre_struct {
   char *pre_mod;
   char *pre_gen;
   char *comment;
} pre_params[] = {

   {
   "HMujfBWu4LfBFA0j3PpN7UbgUYfv.rMoMNuVRMoekpZ", "2", NULL}, {
      "W2KsCfRxb3/ELBvnVWufMA0gbdBlLXbJihgZkgp3xLTKwtPCUhSOHNZ5VLb9pBGR",
          "2", NULL}, {
      "3Kn/YYiomHkFkfM1x4kayR125MGkzpLUDy3y14FlTMwYnhZkjrMXnoC2TcFAecNlU5kFzgcpKYUbBOPZFRtyf3",
          "2", NULL}, {
      "CbDP.jR6YD6wAj2ByQWxQxQZ7.9J9xkn2.Uqb3zVm16vQyizprhBw9hi80psatZ8k54vwZfiIeEHZVsDnyqeWSSIpWso.wh5GD4OFgdhVI3",
          "2", NULL}, {
      "iqJ7nFZ4bGCRjE1F.FXEwL085Zb0kLM2TdHDaVVCdq0cKxvnH/0FLskJTKlDtt6sDl89dc//aEULTVFGtcbA/tDzc.bnFE.DWthQOu2n2JwKjgKfgCR2lZFWXdnWmoOh",
          "2", NULL}, {
      "///////////93zgY8MZ2DCJ6Oek0t1pHAG9E28fdp7G22xwcEnER8b5A27cED0JTxvKPiyqwGnimAmfjybyKDq/XDMrjKS95v8MrTc9UViRqJ4BffZes8F//////////",
          "7", "oakley prime 1"}, {
      "Ewl2hcjiutMd3Fu2lgFnUXWSc67TVyy2vwYCKoS9MLsrdJVT9RgWTCuEqWJrfB6uE3LsE9GkOlaZabS7M29sj5TnzUqOLJMjiwEzArfiLr9WbMRANlF68N5AVLcPWvNx6Zjl3m5Scp0BzJBz9TkgfhzKJZ.WtP3Mv/67I/0wmRZ",
          "2", NULL}, {
      "F//////////oG/QeY5emZJ4ncABWDmSqIa2JWYAPynq0Wk.fZiJco9HIWXvZZG4tU.L6RFDEaCRC2iARV9V53TFuJLjRL72HUI5jNPYNdx6z4n2wQOtxMiB/rosz0QtxUuuQ/jQYP.bhfya4NnB7.P9A6PHxEPJWV//////////",
          "5", "oakley prime 2"}, {
      "3NUKQ2Re4P5BEK0TLg2dX3gETNNNECPoe92h4OVMaDn3Xo/0QdjgG/EvM.hiVV1BdIGklSI14HA38Mpe5k04juR5/EXMU0r1WtsLhNXwKBlf2zEfoOh0zVmDvqInpU695f29Iy7sNW3U5RIogcs740oUp2Kdv5wuITwnIx84cnO.e467/IV1lPnvMCr0pd1dgS0a.RV5eBJr03Q65Xy61R",
          "2", NULL}, {
      "dUyyhxav9tgnyIg65wHxkzkb7VIPh4o0lkwfOKiPp4rVJrzLRYVBtb76gKlaO7ef5LYGEw3G.4E0jbMxcYBetDy2YdpiP/3GWJInoBbvYHIRO9uBuxgsFKTKWu7RnR7yTau/IrFTdQ4LY/q.AvoCzMxV0PKvD9Odso/LFIItn8PbTov3VMn/ZEH2SqhtpBUkWtmcIkEflhX/YY/fkBKfBbe27/zUaKUUZEUYZ2H2nlCL60.JIPeZJSzsu/xHDVcx",
          "2", NULL}, {
      "2iQzj1CagQc/5ctbuJYLWlhtAsPHc7xWVyCPAKFRLWKADpASkqe9djWPFWTNTdeJtL8nAhImCn3Sr/IAdQ1FrGw0WvQUstPx3FO9KNcXOwisOQ1VlL.gheAHYfbYyBaxXL.NcJx9TUwgWDT0hRzFzqSrdGGTN3FgSTA1v4QnHtEygNj3eZ.u0MThqWUaDiP87nqha7XnT66bkTCkQ8.7T8L4KZjIImrNrUftedTTBi.WCi.zlrBxDuOM0da0JbUkQlXqvp0yvJAPpC11nxmmZOAbQOywZGmu9nhZNuwTlxjfIro0FOdthaDTuZRL9VL7MRPUDo/DQEyW.d4H.UIlzp",
          "2", NULL}
};

#define NPARAMS (sizeof(pre_params) / sizeof(struct pre_struct))

char *progName;

int debug = 0;
int verbose = 0;
int composite = 0;

int main(int argc, char *argv[])
{
   char *chp;
   char configFile[256] = { 0 };
   char cbuf[256];
   char b64buf[MAXB64PARAMLEN];
   int c, ch, i, lastidx, keylen, yesno, fsize;
   FILE *efp;

   struct t_conf *tc = NULL;
   struct t_confent *tcent;

   progName = *argv;
   if ((chp = strrchr(progName, '/')) != (char *) 0)
      progName = chp + 1;

   while ((ch = getopt(argc, argv, "dv2c:")) != EOF)
      switch (ch) {
      case 'c':
         strcpy(configFile, optarg);
         break;
      case 'v':
         verbose++;
         break;
      case 'd':
         debug++;
         break;
      case '2':
         composite++;
         break;
      default:
         fprintf(stderr, "usage: %s [-dv2] [-c configfile]\n", progName);
         exit(1);
      }

   argc -= optind;
   argv += optind;

   if (configFile[0] == '\0' && getenv("HOME"))
      sprintf(configFile, "%s/%s", getenv("HOME"), SROOTDCONF);

   efp = fopen(configFile, "a+");
   if (efp == NULL) {
      if (creat(configFile, 0644) < 0
          || (efp = fopen(configFile, "a+")) == NULL) {
         fprintf(stderr, "%s: unable to create %s (errno = %d)\n",
                 progName, configFile, errno);
         exit(2);
      } else
         printf("%s: Creating new configuration file %s\n", progName,
                configFile);
   }

   tc = t_openconf(efp);
   if (tc == NULL) {
      fprintf(stderr, "%s: unable to open configuration file %s\n",
              progName, configFile);
      exit(2);
   }

   tcent = t_getconflast(tc);
   if (tcent == NULL)
      lastidx = 0;
   else
      lastidx = tcent->index;

   if (lastidx > 0) {
      keylen = 8 * tcent->modulus.len;
      printf("Current field size is %d bits.\n", keylen);
      printf("\nIncrease the default field size? [y] ");
      yesno = 0;
      while ((c = getchar()) != '\n' && c != EOF) {
         if (yesno == 0) {
            if (c == 'n' || c == 'N')
               yesno = -1;
            else if (c == 'y' || c == 'Y')
               yesno = 1;
         }
      }
      if (c == EOF || yesno < 0)
         exit(0);
   } else {
      lastidx = 0;
      keylen = 0;
   }

   tcent = t_newconfent(tc);

   printf("\nGenerate a (n)ew field or use a (p)redefined field? [nP] ");
   fgets(cbuf, sizeof(cbuf), stdin);
   if (*cbuf != 'n' && *cbuf != 'N') {
      for (i = 0; i < (int)NPARAMS; ++i) {
         tcent->modulus.len = t_fromb64((char *)tcent->modulus.data,
                                        pre_params[i].pre_mod);
         printf("(%d) [%d bits]  %s\n    Modulus = %s\n  Generator = %s\n",
                i + 1, 8 * tcent->modulus.len,
                pre_params[i].comment ? pre_params[i].comment : "",
                pre_params[i].pre_mod, pre_params[i].pre_gen);
      }
      printf("\nSelect a field (1-%d): ", NPARAMS);
      fgets(cbuf, sizeof(cbuf), stdin);
      i = atoi(cbuf);
      if (i <= 0 || i > (int)NPARAMS) {
         fprintf(stderr, "Index not in range\n");
         exit(1);
      }
      tcent->index = lastidx + 1;
      tcent->modulus.len = t_fromb64((char *)tcent->modulus.data,
                                     pre_params[i - 1].pre_mod);
      tcent->generator.len = t_fromb64((char *)tcent->generator.data,
                                       pre_params[i - 1].pre_gen);
      t_putconfent(tcent, efp);
      t_closeconf(tc);
      fclose(efp);
      printf("Configuration file updated.\n");
      exit(0);
   }

   printf("\nEnter the new field size, in bits.  Suggested sizes:\n\n");
   printf(" %3d (minimum, testing only)\n", MIN_BASIS_BITS);
   printf(" 384 (low security, but fast)\n");
   printf(" 512 (reasonable default)\n");
   printf(" 768 (better security)\n");
   printf("1024 (PGP-level security)\n");
   printf("1536 (extremely secure, possibly slow)\n");
   printf("2048 (maximum supported security level)\n");
   printf("\nField size (%d to %d): ", MIN_BASIS_BITS, BASIS_BITS);

   fgets(cbuf, sizeof(cbuf), stdin);
   fsize = atoi(cbuf);
   if (fsize < MIN_BASIS_BITS || fsize > BASIS_BITS) {
      fprintf(stderr, "%s: field size must be between %d and %d\n",
              progName, MIN_BASIS_BITS, BASIS_BITS);
      exit(1);
   }

   if (fsize <= keylen)
      fprintf(stderr, "Warning: new field size is not larger than old field size\n");

   printf("\nInitializing random number generator...");
   fflush(stdout);
   t_stronginitrand();

   if (composite)
      printf
          ("done.\n\nGenerating a %d-bit composite with safe prime factors.  This may take a while.\n",
           fsize);
   else
      printf
          ("done.\n\nGenerating a %d-bit safe prime.  This may take a while.\n",
           fsize);

   while (1) {
      while ((tcent = (composite ? t_makeconfent_c(tc, fsize) :
                       t_makeconfent(tc, fsize))) == NULL)
         printf("Parameter generation failed, retrying...\n");
      tcent->index = lastidx + 1;

      printf("\nParameters successfully generated.\n");
      printf("N = [%s]\n", t_tob64(b64buf,
                                   (char *)tcent->modulus.data,
                                   tcent->modulus.len));
      printf("g = [%s]\n",
             t_tob64(b64buf,
                     (char *)tcent->generator.data, tcent->generator.len));
      printf("\nUpdate the configuration file with these parameters? [Ynq] ");

      fgets(cbuf, sizeof(cbuf), stdin);
      switch (*cbuf) {
      case 'q':
      case 'Q':
         fclose(efp);
         exit(0);
      case 'n':
      case 'N':
         printf("\nGenerating another set of parameters, please wait...\n");
         break;
      default:
         t_putconfent(tcent, efp);
         t_closeconf(tc);
         fclose(efp);
         printf("Configuration file updated.\n");
         exit(0);
      }
   }
}