view libtomcrypt/src/modes/ctr/ctr_test.c @ 1790:42745af83b7d

Introduce extra delay before closing unauthenticated sessions To make it harder for attackers, introduce a delay to keep an unauthenticated session open a bit longer, thus blocking a connection slot until after the delay. Without this, while there is a limit on the amount of attempts an attacker can make at the same time (MAX_UNAUTH_PER_IP), the time taken by dropbear to handle one attempt is still short and thus for each of the allowed parallel attempts many attempts can be chained one after the other. The attempt rate is then: "MAX_UNAUTH_PER_IP / <process time of one attempt>". With the delay, this rate becomes: "MAX_UNAUTH_PER_IP / UNAUTH_CLOSE_DELAY".
author Thomas De Schampheleire <thomas.de_schampheleire@nokia.com>
date Wed, 15 Feb 2017 13:53:04 +0100
parents 6dba84798cd5
children
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/* 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"

/**
  @file ctr_test.c
  CTR implementation, Tests again RFC 3686, Tom St Denis
*/

#ifdef LTC_CTR_MODE

int ctr_test(void)
{
#ifdef LTC_NO_TEST
   return CRYPT_NOP;
#else
   static const struct {
      int keylen, msglen;
      unsigned char key[32], IV[16], pt[64], ct[64];
   } tests[] = {
/* 128-bit key, 16-byte pt */
{
   16, 16,
   {0xAE,0x68,0x52,0xF8,0x12,0x10,0x67,0xCC,0x4B,0xF7,0xA5,0x76,0x55,0x77,0xF3,0x9E },
   {0x00,0x00,0x00,0x30,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 },
   {0x53,0x69,0x6E,0x67,0x6C,0x65,0x20,0x62,0x6C,0x6F,0x63,0x6B,0x20,0x6D,0x73,0x67 },
   {0xE4,0x09,0x5D,0x4F,0xB7,0xA7,0xB3,0x79,0x2D,0x61,0x75,0xA3,0x26,0x13,0x11,0xB8 },
},

/* 128-bit key, 36-byte pt */
{
   16, 36,
   {0x76,0x91,0xBE,0x03,0x5E,0x50,0x20,0xA8,0xAC,0x6E,0x61,0x85,0x29,0xF9,0xA0,0xDC },
   {0x00,0xE0,0x01,0x7B,0x27,0x77,0x7F,0x3F,0x4A,0x17,0x86,0xF0,0x00,0x00,0x00,0x00 },
   {0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0A,0x0B,0x0C,0x0D,0x0E,0x0F,
    0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17,0x18,0x19,0x1A,0x1B,0x1C,0x1D,0x1E,0x1F,
    0x20,0x21,0x22,0x23},
   {0xC1,0xCF,0x48,0xA8,0x9F,0x2F,0xFD,0xD9,0xCF,0x46,0x52,0xE9,0xEF,0xDB,0x72,0xD7,
    0x45,0x40,0xA4,0x2B,0xDE,0x6D,0x78,0x36,0xD5,0x9A,0x5C,0xEA,0xAE,0xF3,0x10,0x53,
    0x25,0xB2,0x07,0x2F },
},
};
  int idx, err, x;
  unsigned char buf[64];
  symmetric_CTR ctr;

  /* AES can be under rijndael or aes... try to find it */
  if ((idx = find_cipher("aes")) == -1) {
     if ((idx = find_cipher("rijndael")) == -1) {
        return CRYPT_NOP;
     }
  }

  for (x = 0; x < (int)(sizeof(tests)/sizeof(tests[0])); x++) {
     if ((err = ctr_start(idx, tests[x].IV, tests[x].key, tests[x].keylen, 0, CTR_COUNTER_BIG_ENDIAN|LTC_CTR_RFC3686, &ctr)) != CRYPT_OK) {
        return err;
     }
     if ((err = ctr_encrypt(tests[x].pt, buf, tests[x].msglen, &ctr)) != CRYPT_OK) {
        return err;
     }
     ctr_done(&ctr);
     if (compare_testvector(buf, tests[x].msglen, tests[x].ct, tests[x].msglen, "CTR", x)) {
        return CRYPT_FAIL_TESTVECTOR;
     }
  }
  return CRYPT_OK;
#endif
}

#endif

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