view libtomcrypt/demos/sizes.c @ 1715:3974f087d9c0

Disallow leading lines before the ident for server (#102) Per RFC4253 4.2 clients must be able to process other lines of data before the version string, server behavior is not defined neither with MUST/SHOULD nor with MAY. If server process up to 50 lines too - it may cause too long hanging session with invalid/evil client that consume host resources and potentially may lead to DDoS on poor embedded boxes. Let's require first line from client to be version string and fail early if it's not - matches both RFC and real OpenSSH behavior.
author Vladislav Grishenko <themiron@users.noreply.github.com>
date Mon, 15 Jun 2020 18:22:18 +0500
parents e9dba7abd939
children
line wrap: on
line source

/* LibTomCrypt, modular cryptographic library -- Tom St Denis
 *
 * LibTomCrypt is a library that provides various cryptographic
 * algorithms in a highly modular and flexible manner.
 *
 * The library is free for all purposes without any express
 * guarantee it works.
 */

#include "tomcrypt.h"

#if defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE >= 200112L
#include <libgen.h>
#else
#define basename(x) x
#endif
/**
  @file demo_crypt_sizes.c

  Demo how to get various sizes to dynamic languages
  like Python - Larry Bugbee, February 2013
*/

static void _print_line(const char* cmd, const char* desc)
{
   printf("  %-16s - %s\n", cmd, desc);
}

int main(int argc, char **argv)
{
   if (argc == 1) {
      /* given a specific size name, get and print its size */
      char name[] = "ltc_hash_descriptor";
      unsigned int size;
      char *sizes_list;
      unsigned int sizes_list_len;
      if (crypt_get_size(name, &size) != 0) exit(EXIT_FAILURE);
      printf("\n  size of '%s' is %u \n\n", name, size);

      /* get and print the length of the names (and sizes) list */
      if (crypt_list_all_sizes(NULL, &sizes_list_len) != 0) exit(EXIT_FAILURE);
      printf("  need to allocate %u bytes \n\n", sizes_list_len);

      /* get and print the names (and sizes) list */
      if ((sizes_list = malloc(sizes_list_len)) == NULL) exit(EXIT_FAILURE);
      if (crypt_list_all_sizes(sizes_list, &sizes_list_len) != 0) exit(EXIT_FAILURE);
      printf("  supported sizes:\n\n%s\n\n", sizes_list);
      free(sizes_list);
   } else if (argc == 2) {
      if (strcmp(argv[1], "-h") == 0 || strcmp(argv[1], "--help") == 0) {
         char* base = strdup(basename(argv[0]));
         printf("Usage: %s [-a] [-s name]\n\n", base);
         _print_line("<no argument>", "The old behavior of the demo");
         _print_line("-a", "Only lists all sizes");
         _print_line("-s name", "List a single size given as argument");
         _print_line("-h", "The help you're looking at");
         free(base);
      } else if (strcmp(argv[1], "-a") == 0) {
         char *sizes_list;
         unsigned int sizes_list_len;
         /* get and print the length of the names (and sizes) list */
         if (crypt_list_all_sizes(NULL, &sizes_list_len) != 0) exit(EXIT_FAILURE);
         /* get and print the names (and sizes) list */
         if ((sizes_list = malloc(sizes_list_len)) == NULL) exit(EXIT_FAILURE);
         if (crypt_list_all_sizes(sizes_list, &sizes_list_len) != 0) exit(EXIT_FAILURE);
         printf("%s\n", sizes_list);
         free(sizes_list);
      }
   } else if (argc == 3) {
      if (strcmp(argv[1], "-s") == 0) {
         unsigned int size;
         if (crypt_get_size(argv[2], &size) != 0) exit(EXIT_FAILURE);
         printf("%s,%u\n", argv[2], size);
      }
   }
   return 0;
}

/* ref:         $Format:%D$ */
/* git commit:  $Format:%H$ */
/* commit time: $Format:%ai$ */