view libtomcrypt/tests/katja_test.c @ 1788:1fc0012b9c38

Fix handling of replies to global requests (#112) The current code assumes that all global requests want / need a reply. This isn't always true and the request itself indicates if it wants a reply or not. It causes a specific problem with [email protected] messages. These are sent by OpenSSH after authentication to inform the client of potential other host keys for the host. This can be used to add a new type of host key or to rotate host keys. The initial information message from the server is sent as a global request, but with want_reply set to false. This means that the server doesn't expect an answer to this message. Instead the client needs to send a prove request as a reply if it wants to receive proof of ownership for the host keys. The bug doesn't cause any current problems with due to how OpenSSH treats receiving the failure message. It instead treats it as a keepalive message and further ignores it. Arguably this is a protocol violation though of Dropbear and it is only accidental that it doesn't cause a problem with OpenSSH. The bug was found when adding host keys support to libssh, which is more strict protocol wise and treats the unexpected failure message an error, also see https://gitlab.com/libssh/libssh-mirror/-/merge_requests/145 for more information. The fix here is to honor the want_reply flag in the global request and to only send a reply if the other side expects a reply.
author Dirkjan Bussink <d.bussink@gmail.com>
date Thu, 10 Dec 2020 16:13:13 +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_test.h>

#if defined(LTC_MKAT) && defined(LTC_TEST_MPI)

int katja_test(void)
{
   unsigned char in[1024], out[1024], tmp[1024];
   katja_key     key, privKey, pubKey;
   int           hash_idx, prng_idx, stat, stat2, size;
   unsigned long kat_msgsize, len, len2, cnt;
   static unsigned char lparam[] = { 0x01, 0x02, 0x03, 0x04 };

   hash_idx = find_hash("sha1");
   prng_idx = find_prng("yarrow");
   if (hash_idx == -1 || prng_idx == -1) {
      fprintf(stderr, "katja_test requires LTC_SHA1 and yarrow");
      return 1;
   }

for (size = 1024; size <= 2048; size += 256) {

   /* make 10 random key */
   for (cnt = 0; cnt < 10; cnt++) {
      DO(katja_make_key(&yarrow_prng, prng_idx, size/8, &key));
      if (mp_count_bits(key.N) < size - 7) {
         fprintf(stderr, "katja_%d key modulus has %d bits\n", size, mp_count_bits(key.N));

len = mp_unsigned_bin_size(key.N);
mp_to_unsigned_bin(key.N, tmp);
 fprintf(stderr, "N == \n");
for (cnt = 0; cnt < len; ) {
   fprintf(stderr, "%02x ", tmp[cnt]);
   if (!(++cnt & 15)) fprintf(stderr, "\n");
}

len = mp_unsigned_bin_size(key.p);
mp_to_unsigned_bin(key.p, tmp);
 fprintf(stderr, "p == \n");
for (cnt = 0; cnt < len; ) {
   fprintf(stderr, "%02x ", tmp[cnt]);
   if (!(++cnt & 15)) fprintf(stderr, "\n");
}

len = mp_unsigned_bin_size(key.q);
mp_to_unsigned_bin(key.q, tmp);
 fprintf(stderr, "\nq == \n");
for (cnt = 0; cnt < len; ) {
   fprintf(stderr, "%02x ", tmp[cnt]);
   if (!(++cnt & 15)) fprintf(stderr, "\n");
}
 fprintf(stderr, "\n");


         return 1;
      }
      if (cnt != 9) {
         katja_free(&key);
      }
   }
   /* encrypt the key (without lparam) */
   for (cnt = 0; cnt < 4; cnt++) {
   for (kat_msgsize = 1; kat_msgsize <= 42; kat_msgsize++) {
      /* make a random key/msg */
      yarrow_read(in, kat_msgsize, &yarrow_prng);

      len  = sizeof(out);
      len2 = kat_msgsize;

      DO(katja_encrypt_key(in, kat_msgsize, out, &len, NULL, 0, &yarrow_prng, prng_idx, hash_idx, &key));
      /* change a byte */
      out[8] ^= 1;
      DO(katja_decrypt_key(out, len, tmp, &len2, NULL, 0, hash_idx, &stat2, &key));
      /* change a byte back */
      out[8] ^= 1;
      if (len2 != kat_msgsize) {
         fprintf(stderr, "\nkatja_decrypt_key mismatch len %lu (first decrypt)", len2);
         return 1;
      }

      len2 = kat_msgsize;
      DO(katja_decrypt_key(out, len, tmp, &len2, NULL, 0, hash_idx, &stat, &key));
      if (!(stat == 1 && stat2 == 0)) {
         fprintf(stderr, "katja_decrypt_key failed");
         return 1;
      }
      if (len2 != kat_msgsize || memcmp(tmp, in, kat_msgsize)) {
         unsigned long x;
         fprintf(stderr, "\nkatja_decrypt_key mismatch, len %lu (second decrypt)\n", len2);
         fprintf(stderr, "Original contents: \n");
         for (x = 0; x < kat_msgsize; ) {
             fprintf(stderr, "%02x ", in[x]);
             if (!(++x % 16)) {
                fprintf(stderr, "\n");
             }
         }
         fprintf(stderr, "\n");
         fprintf(stderr, "Output contents: \n");
         for (x = 0; x < kat_msgsize; ) {
             fprintf(stderr, "%02x ", out[x]);
             if (!(++x % 16)) {
                fprintf(stderr, "\n");
             }
         }
         fprintf(stderr, "\n");
         return 1;
      }
   }
   }

   /* encrypt the key (with lparam) */
   for (kat_msgsize = 1; kat_msgsize <= 42; kat_msgsize++) {
      len  = sizeof(out);
      len2 = kat_msgsize;
      DO(katja_encrypt_key(in, kat_msgsize, out, &len, lparam, sizeof(lparam), &yarrow_prng, prng_idx, hash_idx, &key));
      /* change a byte */
      out[8] ^= 1;
      DO(katja_decrypt_key(out, len, tmp, &len2, lparam, sizeof(lparam), hash_idx, &stat2, &key));
      if (len2 != kat_msgsize) {
         fprintf(stderr, "\nkatja_decrypt_key mismatch len %lu (first decrypt)", len2);
         return 1;
      }
      /* change a byte back */
      out[8] ^= 1;

      len2 = kat_msgsize;
      DO(katja_decrypt_key(out, len, tmp, &len2, lparam, sizeof(lparam), hash_idx, &stat, &key));
      if (!(stat == 1 && stat2 == 0)) {
         fprintf(stderr, "katja_decrypt_key failed");
         return 1;
      }
      if (len2 != kat_msgsize || memcmp(tmp, in, kat_msgsize)) {
         fprintf(stderr, "katja_decrypt_key mismatch len %lu", len2);
         return 1;
      }
   }

#if 0

   /* sign a message (unsalted, lower cholestorol and Atkins approved) now */
   len = sizeof(out);
   DO(katja_sign_hash(in, 20, out, &len, &yarrow_prng, prng_idx, hash_idx, 0, &key));

/* export key and import as both private and public */
   len2 = sizeof(tmp);
   DO(katja_export(tmp, &len2, PK_PRIVATE, &key));
   DO(katja_import(tmp, len2, &privKey));
   len2 = sizeof(tmp);
   DO(katja_export(tmp, &len2, PK_PUBLIC, &key));
   DO(katja_import(tmp, len2, &pubKey));

   /* verify with original */
   DO(katja_verify_hash(out, len, in, 20, hash_idx, 0, &stat, &key));
   /* change a byte */
   in[0] ^= 1;
   DO(katja_verify_hash(out, len, in, 20, hash_idx, 0, &stat2, &key));

   if (!(stat == 1 && stat2 == 0)) {
      fprintf(stderr, "katja_verify_hash (unsalted, origKey) failed, %d, %d", stat, stat2);
      katja_free(&key);
      katja_free(&pubKey);
      katja_free(&privKey);
      return 1;
   }

   /* verify with privKey */
   /* change a byte */
   in[0] ^= 1;
   DO(katja_verify_hash(out, len, in, 20, hash_idx, 0, &stat, &privKey));
   /* change a byte */
   in[0] ^= 1;
   DO(katja_verify_hash(out, len, in, 20, hash_idx, 0, &stat2, &privKey));

   if (!(stat == 1 && stat2 == 0)) {
      fprintf(stderr, "katja_verify_hash (unsalted, privKey) failed, %d, %d", stat, stat2);
      katja_free(&key);
      katja_free(&pubKey);
      katja_free(&privKey);
      return 1;
   }

   /* verify with pubKey */
   /* change a byte */
   in[0] ^= 1;
   DO(katja_verify_hash(out, len, in, 20, hash_idx, 0, &stat, &pubKey));
   /* change a byte */
   in[0] ^= 1;
   DO(katja_verify_hash(out, len, in, 20, hash_idx, 0, &stat2, &pubKey));

   if (!(stat == 1 && stat2 == 0)) {
      fprintf(stderr, "katja_verify_hash (unsalted, pubkey) failed, %d, %d", stat, stat2);
      katja_free(&key);
      katja_free(&pubKey);
      katja_free(&privKey);
      return 1;
   }

   /* sign a message (salted) now (use privKey to make, pubKey to verify) */
   len = sizeof(out);
   DO(katja_sign_hash(in, 20, out, &len, &yarrow_prng, prng_idx, hash_idx, 8, &privKey));
   DO(katja_verify_hash(out, len, in, 20, hash_idx, 8, &stat, &pubKey));
   /* change a byte */
   in[0] ^= 1;
   DO(katja_verify_hash(out, len, in, 20, hash_idx, 8, &stat2, &pubKey));

   if (!(stat == 1 && stat2 == 0)) {
      fprintf(stderr, "katja_verify_hash (salted) failed, %d, %d", stat, stat2);
      katja_free(&key);
      katja_free(&pubKey);
      katja_free(&privKey);
      return 1;
   }
#endif

   katja_free(&key);
   katja_free(&pubKey);
   katja_free(&privKey);
}

   /* free the key and return */
   return 0;
}

#else

int katja_test(void)
{
   return CRYPT_NOP;
}

#endif

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