Fossil

*/
#include "config.h"
#include "util.h"
#if defined(USE_MMAN_H)
# include <sys/mman.h>
# include <unistd.h>
#endif
#include <math.h>

/*
** For the fossil_timer_xxx() family of functions...
*/
#ifdef _WIN32
# include <windows.h>
#else

  ** "1" and "I"  that might be easily confused */
  static const char zAlphabet[] =
           /*  0         1         2         3         4         5       */
           /*   123456789 123456789 123456789 123456789 123456789 123456 */
              "23456789abcdefghijkmnopqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ";

  if( N<8 ) N = 8;
  else if( N>sizeof(zAlphabet)-2 ) N = sizeof(zAlphabet)-2;
  nSrc = sizeof(zAlphabet) - 1;
  if( N>nSrc ) N = nSrc;
  memcpy(zSrc, zAlphabet, nSrc);

  for(i=0; i<N; i++){
    unsigned r;
    sqlite3_randomness(sizeof(r), &r);
    r %= nSrc;
    z[i] = zSrc[r];
    zSrc[r] = zSrc[--nSrc];
  }
  z[i] = 0;
  return fossil_strdup(z);
}

/*
** COMMAND: test-random-password
**
** Usage: %fossil test-random-password ?N?
** Usage: %fossil test-random-password [N] [--entropy]
**
** Generate a random password string of approximately N characters in length.
** If N is omitted, use 10.  Values of N less than 8 are changed to 8
** and greater than 55 and changed to 55.
** If N is omitted, use 12.  Values of N less than 8 are changed to 8
** and greater than 57 and changed to 57.
**
** If the --entropy flag is included, the number of bits of entropy in
** the password is show as well.
*/
void test_random_password(void){
  int N = 10;
  if( g.argc>=3 ){
    N = atoi(g.argv[2]);
  }
  fossil_print("%s\n", fossil_random_password(N));
  int N = 12;
  int showEntropy = 0;
  int i;
  char *zPassword;
  for(i=2; i<g.argc; i++){
    const char *z = g.argv[i];
    if( z[0]=='-' && z[1]=='-' ) z++;
    if( strcmp(z,"-entropy")==0 ){
      showEntropy = 1;
    }else if( fossil_isdigit(z[0]) ){
      N = atoi(z);
      if( N<8 ) N = 8;
      if( N>57 ) N = 57;
    }else{
      usage("[N] [--entropy]");
    }
  }
  zPassword = fossil_random_password(N);
  if( showEntropy ){
    double et = 57.0;
    for(i=1; i<N; i++) et *= 57-i;
    fossil_print("%s (%d bits of entropy)\n", zPassword,
                 (int)(log(et)/log(2.0)));
  }else{
    fossil_print("%s\n", zPassword);
  }
  fossil_free(zPassword);
}

/*
** Return the number of decimal digits in a nonnegative integer.  This is useful
** when formatting text.
*/
int fossil_num_digits(int n){
  return n<      10 ? 1 : n<      100 ? 2 : n<      1000 ? 3
       : n<   10000 ? 4 : n<   100000 ? 5 : n<   1000000 ? 6
       : n<10000000 ? 7 : n<100000000 ? 8 : n<1000000000 ? 9 : 10;
}