manual/examples/genpass.c

   1 #include <stdio.h>
   2 #include <time.h>
   3 #include <unistd.h>
   4 #include <crypt.h>
   5
   6 int
   7 main(void)
   8 {
   9   unsigned long seed[2];
  10   char salt[] = "$1$........";
  11   const char *const seedchars =
  12     "./0123456789ABCDEFGHIJKLMNOPQRST"
  13     "UVWXYZabcdefghijklmnopqrstuvwxyz";
  14   char *password;
  15   int i;
  16
  17   /* Generate a (not very) random seed.
  18      You should do it better than this...  */
  19   seed[0] = time(NULL);
  20   seed[1] = getpid() ^ (seed[0] >> 14 & 0x30000);
  21
  22   /* Turn it into printable characters from `seedchars'.  */
  23   for (i = 0; i < 8; i++)
  24     salt[3+i] = seedchars[(seed[i/5] >> (i%5)*6) & 0x3f];
  25
  26   /* Read in the user's password and encrypt it.  */
  27   password = crypt(getpass("Password:"), salt);
  28
  29   /* Print the results.  */
  30   puts(password);
  31   return 0;
  32 }