Exemplo n.º 1
0
/**
 * Given a curve25519 keypair in <b>inp</b>, generate a corresponding
 * ed25519 keypair in <b>out</b>, and set <b>signbit_out</b> to the
 * sign bit of the X coordinate of the ed25519 key.
 *
 * NOTE THAT IT IS PROBABLY NOT SAFE TO USE THE GENERATED KEY FOR ANYTHING
 * OUTSIDE OF WHAT'S PRESENTED IN PROPOSAL 228.  In particular, it's probably
 * not a great idea to use it to sign attacker-supplied anything.
 */
int
ed25519_keypair_from_curve25519_keypair(ed25519_keypair_t *out,
                                        int *signbit_out,
                                        const curve25519_keypair_t *inp)
{
  const char string[] = "Derive high part of ed25519 key from curve25519 key";
  ed25519_public_key_t pubkey_check;
  SHA512_CTX ctx;
  uint8_t sha512_output[64];

  memcpy(out->seckey.seckey, inp->seckey.secret_key, 32);
  SHA512_Init(&ctx);
  SHA512_Update(&ctx, out->seckey.seckey, 32);
  SHA512_Update(&ctx, string, sizeof(string));
  SHA512_Final(sha512_output, &ctx);
  memcpy(out->seckey.seckey + 32, sha512_output, 32);

  ed25519_public_key_generate(&out->pubkey, &out->seckey);

  *signbit_out = out->pubkey.pubkey[31] >> 7;

  ed25519_public_key_from_curve25519_public_key(&pubkey_check, &inp->pubkey,
                                                *signbit_out);

  tor_assert(fast_memeq(pubkey_check.pubkey, out->pubkey.pubkey, 32));

  memwipe(&pubkey_check, 0, sizeof(pubkey_check));
  memwipe(&ctx, 0, sizeof(ctx));
  memwipe(sha512_output, 0, sizeof(sha512_output));

  return 0;
}
Exemplo n.º 2
0
Arquivo: bench.c Projeto: 1234max/tor
static void
bench_ed25519_impl(void)
{
  uint64_t start, end;
  const int iters = 1<<12;
  int i;
  const uint8_t msg[] = "but leaving, could not tell what they had heard";
  ed25519_signature_t sig;
  ed25519_keypair_t kp;
  curve25519_keypair_t curve_kp;
  ed25519_public_key_t pubkey_tmp;

  ed25519_secret_key_generate(&kp.seckey, 0);
  start = perftime();
  for (i = 0; i < iters; ++i) {
    ed25519_public_key_generate(&kp.pubkey, &kp.seckey);
  }
  end = perftime();
  printf("Generate public key: %.2f usec\n",
         MICROCOUNT(start, end, iters));

  start = perftime();
  for (i = 0; i < iters; ++i) {
    ed25519_sign(&sig, msg, sizeof(msg), &kp);
  }
  end = perftime();
  printf("Sign a short message: %.2f usec\n",
         MICROCOUNT(start, end, iters));

  start = perftime();
  for (i = 0; i < iters; ++i) {
    ed25519_checksig(&sig, msg, sizeof(msg), &kp.pubkey);
  }
  end = perftime();
  printf("Verify signature: %.2f usec\n",
         MICROCOUNT(start, end, iters));

  curve25519_keypair_generate(&curve_kp, 0);
  start = perftime();
  for (i = 0; i < iters; ++i) {
    ed25519_public_key_from_curve25519_public_key(&pubkey_tmp,
                                                  &curve_kp.pubkey, 1);
  }
  end = perftime();
  printf("Convert public point from curve25519: %.2f usec\n",
         MICROCOUNT(start, end, iters));

  curve25519_keypair_generate(&curve_kp, 0);
  start = perftime();
  for (i = 0; i < iters; ++i) {
    ed25519_public_blind(&pubkey_tmp, &kp.pubkey, msg);
  }
  end = perftime();
  printf("Blind a public key: %.2f usec\n",
         MICROCOUNT(start, end, iters));
}
Exemplo n.º 3
0
/** Generate a new ed25519 keypair in <b>keypair_out</b>.  If
 * <b>extra_strong</b> is set, try to mix some system entropy into the key
 * generation process. Return 0 on success, -1 on failure. */
int
ed25519_keypair_generate(ed25519_keypair_t *keypair_out, int extra_strong)
{
  if (ed25519_secret_key_generate(&keypair_out->seckey, extra_strong) < 0)
    return -1;
  if (ed25519_public_key_generate(&keypair_out->pubkey,
                                  &keypair_out->seckey)<0)
    return -1;
  return 0;
}
Exemplo n.º 4
0
/**
 * Given an ed25519 keypair in <b>inp</b>, generate a corresponding
 * ed25519 keypair in <b>out</b>, blinded by the corresponding 32-byte input
 * in 'param'.
 *
 * Tor uses key blinding for the "next-generation" hidden services design:
 * service descriptors are encrypted with a key derived from the service's
 * long-term public key, and then signed with (and stored at a position
 * indexed by) a short-term key derived by blinding the long-term keys.
 */
int
ed25519_keypair_blind(ed25519_keypair_t *out,
                      const ed25519_keypair_t *inp,
                      const uint8_t *param)
{
  ed25519_public_key_t pubkey_check;

  get_ed_impl()->blind_secret_key(out->seckey.seckey,
                                  inp->seckey.seckey, param);

  ed25519_public_blind(&pubkey_check, &inp->pubkey, param);
  ed25519_public_key_generate(&out->pubkey, &out->seckey);

  tor_assert(fast_memeq(pubkey_check.pubkey, out->pubkey.pubkey, 32));

  memwipe(&pubkey_check, 0, sizeof(pubkey_check));

  return 0;
}
Exemplo n.º 5
0
/**
 * Read an ed25519 key and associated certificates from files beginning with
 * <b>fname</b>, with certificate type <b>cert_type</b>.  On failure, return
 * NULL; on success return the keypair.
 *
 * If INIT_ED_KEY_CREATE is set in <b>flags</b>, then create the key (and
 * certificate if requested) if it doesn't exist, and save it to disk.
 *
 * If INIT_ED_KEY_NEEDCERT is set in <b>flags</b>, load/create a certificate
 * too and store it in *<b>cert_out</b>.  Fail if the cert can't be
 * found/created.  To create a certificate, <b>signing_key</b> must be set to
 * the key that should sign it; <b>now</b> to the current time, and
 * <b>lifetime</b> to the lifetime of the key.
 *
 * If INIT_ED_KEY_REPLACE is set in <b>flags</b>, then create and save new key
 * whether we can read the old one or not.
 *
 * If INIT_ED_KEY_EXTRA_STRONG is set in <b>flags</b>, set the extra_strong
 * flag when creating the secret key.
 *
 * If INIT_ED_KEY_INCLUDE_SIGNING_KEY_IN_CERT is set in <b>flags</b>, and
 * we create a new certificate, create it with the signing key embedded.
 *
 * If INIT_ED_KEY_SPLIT is set in <b>flags</b>, and we create a new key,
 * store the public key in a separate file from the secret key.
 *
 * If INIT_ED_KEY_MISSING_SECRET_OK is set in <b>flags</b>, and we find a
 * public key file but no secret key file, return successfully anyway.
 *
 * If INIT_ED_KEY_OMIT_SECRET is set in <b>flags</b>, do not try to load a
 * secret key unless no public key is found.  Do not return a secret key. (but
 * create and save one if needed).
 *
 * If INIT_ED_KEY_NO_LOAD_SECRET is set in <b>flags</b>, don't try to load
 * a secret key, no matter what.
 *
 * If INIT_ED_KEY_TRY_ENCRYPTED is set, we look for an encrypted secret key
 * and consider encrypting any new secret key.
 *
 * If INIT_ED_KEY_NO_REPAIR is set, and there is any issue loading the keys
 * from disk _other than their absence_ (full or partial), we do not try to
 * replace them.
 *
 * If INIT_ED_KEY_SUGGEST_KEYGEN is set, have log messages about failures
 * refer to the --keygen option.
 *
 * If INIT_ED_KEY_EXPLICIT_FNAME is set, use the provided file name for the
 * secret key file, encrypted or not.
 */
ed25519_keypair_t *
ed_key_init_from_file(const char *fname, uint32_t flags,
                      int severity,
                      const ed25519_keypair_t *signing_key,
                      time_t now,
                      time_t lifetime,
                      uint8_t cert_type,
                      struct tor_cert_st **cert_out)
{
  char *secret_fname = NULL;
  char *encrypted_secret_fname = NULL;
  char *public_fname = NULL;
  char *cert_fname = NULL;
  const char *loaded_secret_fname = NULL;
  int created_pk = 0, created_sk = 0, created_cert = 0;
  const int try_to_load = ! (flags & INIT_ED_KEY_REPLACE);
  const int encrypt_key = !! (flags & INIT_ED_KEY_TRY_ENCRYPTED);
  const int norepair = !! (flags & INIT_ED_KEY_NO_REPAIR);
  const int split = !! (flags & INIT_ED_KEY_SPLIT);
  const int omit_secret = !! (flags & INIT_ED_KEY_OMIT_SECRET);
  const int offline_secret = !! (flags & INIT_ED_KEY_OFFLINE_SECRET);
  const int explicit_fname = !! (flags & INIT_ED_KEY_EXPLICIT_FNAME);

  /* we don't support setting both of these flags at once. */
  tor_assert((flags & (INIT_ED_KEY_NO_REPAIR|INIT_ED_KEY_NEEDCERT)) !=
                      (INIT_ED_KEY_NO_REPAIR|INIT_ED_KEY_NEEDCERT));

  char tag[8];
  tor_snprintf(tag, sizeof(tag), "type%d", (int)cert_type);

  tor_cert_t *cert = NULL;
  char *got_tag = NULL;
  ed25519_keypair_t *keypair = tor_malloc_zero(sizeof(ed25519_keypair_t));

  if (explicit_fname) {
    secret_fname = tor_strdup(fname);
    encrypted_secret_fname = tor_strdup(fname);
  } else {
    tor_asprintf(&secret_fname, "%s_secret_key", fname);
    tor_asprintf(&encrypted_secret_fname, "%s_secret_key_encrypted", fname);
  }
  tor_asprintf(&public_fname, "%s_public_key", fname);
  tor_asprintf(&cert_fname, "%s_cert", fname);

  /* Try to read the secret key. */
  int have_secret = 0;
  int load_secret = try_to_load &&
    !offline_secret &&
    (!omit_secret || file_status(public_fname)==FN_NOENT);
  if (load_secret) {
    int rv = ed25519_seckey_read_from_file(&keypair->seckey,
                                           &got_tag, secret_fname);
    if (rv == 0) {
      have_secret = 1;
      loaded_secret_fname = secret_fname;
      tor_assert(got_tag);
    } else {
      if (errno != ENOENT && norepair) {
        tor_log(severity, LD_OR, "Unable to read %s: %s", secret_fname,
                strerror(errno));
        goto err;
      }
    }
  }

  /* Should we try for an encrypted key? */
  int have_encrypted_secret_file = 0;
  if (!have_secret && try_to_load && encrypt_key) {
    int r = read_encrypted_secret_key(&keypair->seckey,
                                      encrypted_secret_fname);
    if (r > 0) {
      have_secret = 1;
      have_encrypted_secret_file = 1;
      tor_free(got_tag); /* convince coverity we aren't leaking */
      got_tag = tor_strdup(tag);
      loaded_secret_fname = encrypted_secret_fname;
    } else if (errno != ENOENT && norepair) {
      tor_log(severity, LD_OR, "Unable to read %s: %s",
              encrypted_secret_fname, strerror(errno));
      goto err;
    }
  } else {
    if (try_to_load) {
      /* Check if it's there anyway, so we don't replace it. */
      if (file_status(encrypted_secret_fname) != FN_NOENT)
        have_encrypted_secret_file = 1;
    }
  }

  if (have_secret) {
    if (strcmp(got_tag, tag)) {
      tor_log(severity, LD_OR, "%s has wrong tag", loaded_secret_fname);
      goto err;
    }
    /* Derive the public key */
    if (ed25519_public_key_generate(&keypair->pubkey, &keypair->seckey)<0) {
      tor_log(severity, LD_OR, "%s can't produce a public key",
              loaded_secret_fname);
      goto err;
    }
  }

  /* If we do split keys here, try to read the pubkey. */
  int found_public = 0;
  if (try_to_load && (!have_secret || split)) {
    ed25519_public_key_t pubkey_tmp;
    tor_free(got_tag);
    found_public = ed25519_pubkey_read_from_file(&pubkey_tmp,
                                                 &got_tag, public_fname) == 0;
    if (!found_public && errno != ENOENT && norepair) {
      tor_log(severity, LD_OR, "Unable to read %s: %s", public_fname,
              strerror(errno));
      goto err;
    }
    if (found_public && strcmp(got_tag, tag)) {
      tor_log(severity, LD_OR, "%s has wrong tag", public_fname);
      goto err;
    }
    if (found_public) {
      if (have_secret) {
        /* If we have a secret key and we're reloading the public key,
         * the key must match! */
        if (! ed25519_pubkey_eq(&keypair->pubkey, &pubkey_tmp)) {
          tor_log(severity, LD_OR, "%s does not match %s!  If you are trying "
                  "to restore from backup, make sure you didn't mix up the "
                  "key files. If you are absolutely sure that %s is the right "
                  "key for this relay, delete %s or move it out of the way.",
                  public_fname, loaded_secret_fname,
                  loaded_secret_fname, public_fname);
          goto err;
        }
      } else {
        /* We only have the public key; better use that. */
        tor_assert(split);
        memcpy(&keypair->pubkey, &pubkey_tmp, sizeof(pubkey_tmp));
      }
    } else {
      /* We have no public key file, but we do have a secret key, make the
       * public key file! */
      if (have_secret) {
        if (ed25519_pubkey_write_to_file(&keypair->pubkey, public_fname, tag)
            < 0) {
          tor_log(severity, LD_OR, "Couldn't repair %s", public_fname);
          goto err;
        } else {
          tor_log(LOG_NOTICE, LD_OR,
                  "Found secret key but not %s. Regenerating.",
                  public_fname);
        }
      }
    }
  }

  /* If the secret key is absent and it's not allowed to be, fail. */
  if (!have_secret && found_public &&
      !(flags & INIT_ED_KEY_MISSING_SECRET_OK)) {
    if (have_encrypted_secret_file) {
      tor_log(severity, LD_OR, "We needed to load a secret key from %s, "
              "but it was encrypted. Try 'tor --keygen' instead, so you "
              "can enter the passphrase.",
              secret_fname);
    } else {
      tor_log(severity, LD_OR, "We needed to load a secret key from %s, "
              "but couldn't find it. %s", secret_fname,
              (flags & INIT_ED_KEY_SUGGEST_KEYGEN) ?
              "If you're keeping your master secret key offline, you will "
              "need to run 'tor --keygen' to generate new signing keys." :
              "Did you forget to copy it over when you copied the rest of the "
              "signing key material?");
    }
    goto err;
  }

  /* If it's absent, and we're not supposed to make a new keypair, fail. */
  if (!have_secret && !found_public && !(flags & INIT_ED_KEY_CREATE)) {
    if (split) {
      tor_log(severity, LD_OR, "No key found in %s or %s.",
              secret_fname, public_fname);
    } else {
      tor_log(severity, LD_OR, "No key found in %s.", secret_fname);
    }
    goto err;
  }

  /* If the secret key is absent, but the encrypted key would be present,
   * that's an error */
  if (!have_secret && !found_public && have_encrypted_secret_file) {
    tor_assert(!encrypt_key);
    tor_log(severity, LD_OR, "Found an encrypted secret key, "
            "but not public key file %s!", public_fname);
    goto err;
  }

  /* if it's absent, make a new keypair... */
  if (!have_secret && !found_public) {
    tor_free(keypair);
    keypair = ed_key_new(signing_key, flags, now, lifetime,
                         cert_type, &cert);
    if (!keypair) {
      tor_log(severity, LD_OR, "Couldn't create keypair");
      goto err;
    }
    created_pk = created_sk = created_cert = 1;
  }

  /* Write it to disk if we're supposed to do with a new passphrase, or if
   * we just created it. */
  if (created_sk || (have_secret && get_options()->change_key_passphrase)) {
    if (write_secret_key(&keypair->seckey,
                         encrypt_key,
                         secret_fname, tag, encrypted_secret_fname) < 0
        ||
        (split &&
         ed25519_pubkey_write_to_file(&keypair->pubkey, public_fname, tag) < 0)
        ||
        (cert &&
         crypto_write_tagged_contents_to_file(cert_fname, "ed25519v1-cert",
                                 tag, cert->encoded, cert->encoded_len) < 0)) {
      tor_log(severity, LD_OR, "Couldn't write keys or cert to file.");
      goto err;
    }
    goto done;
  }

  /* If we're not supposed to get a cert, we're done. */
  if (! (flags & INIT_ED_KEY_NEEDCERT))
    goto done;

  /* Read a cert. */
  tor_free(got_tag);
  uint8_t certbuf[256];
  ssize_t cert_body_len = crypto_read_tagged_contents_from_file(
                 cert_fname, "ed25519v1-cert",
                 &got_tag, certbuf, sizeof(certbuf));
  if (cert_body_len >= 0 && !strcmp(got_tag, tag))
    cert = tor_cert_parse(certbuf, cert_body_len);

  /* If we got it, check it to the extent we can. */
  int bad_cert = 0;

  if (! cert) {
    tor_log(severity, LD_OR, "Cert was unparseable");
    bad_cert = 1;
  } else if (!tor_memeq(cert->signed_key.pubkey, keypair->pubkey.pubkey,
                        ED25519_PUBKEY_LEN)) {
    tor_log(severity, LD_OR, "Cert was for wrong key");
    bad_cert = 1;
  } else if (signing_key &&
             tor_cert_checksig(cert, &signing_key->pubkey, now) < 0) {
    tor_log(severity, LD_OR, "Can't check certificate");
    bad_cert = 1;
  } else if (cert->cert_expired) {
    tor_log(severity, LD_OR, "Certificate is expired");
    bad_cert = 1;
  } else if (signing_key && cert->signing_key_included &&
             ! ed25519_pubkey_eq(&signing_key->pubkey, &cert->signing_key)) {
    tor_log(severity, LD_OR, "Certificate signed by unexpectd key!");
    bad_cert = 1;
  }

  if (bad_cert) {
    tor_cert_free(cert);
    cert = NULL;
  }

  /* If we got a cert, we're done. */
  if (cert)
    goto done;

  /* If we didn't get a cert, and we're not supposed to make one, fail. */
  if (!signing_key || !(flags & INIT_ED_KEY_CREATE)) {
    tor_log(severity, LD_OR, "Without signing key, can't create certificate");
    goto err;
  }

  /* We have keys but not a certificate, so make one. */
  uint32_t cert_flags = 0;
  if (flags & INIT_ED_KEY_INCLUDE_SIGNING_KEY_IN_CERT)
    cert_flags |= CERT_FLAG_INCLUDE_SIGNING_KEY;
  cert = tor_cert_create(signing_key, cert_type,
                         &keypair->pubkey,
                         now, lifetime,
                         cert_flags);

  if (! cert) {
    tor_log(severity, LD_OR, "Couldn't create certificate");
    goto err;
  }

  /* Write it to disk. */
  created_cert = 1;
  if (crypto_write_tagged_contents_to_file(cert_fname, "ed25519v1-cert",
                             tag, cert->encoded, cert->encoded_len) < 0) {
    tor_log(severity, LD_OR, "Couldn't write cert to disk.");
    goto err;
  }

 done:
  if (cert_out)
    *cert_out = cert;
  else
    tor_cert_free(cert);

  goto cleanup;

 err:
  if (keypair)
    memwipe(keypair, 0, sizeof(*keypair));
  tor_free(keypair);
  tor_cert_free(cert);
  if (cert_out)
    *cert_out = NULL;
  if (created_sk)
    unlink(secret_fname);
  if (created_pk)
    unlink(public_fname);
  if (created_cert)
    unlink(cert_fname);

 cleanup:
  tor_free(encrypted_secret_fname);
  tor_free(secret_fname);
  tor_free(public_fname);
  tor_free(cert_fname);
  tor_free(got_tag);

  return keypair;
}
Exemplo n.º 6
0
static void
test_crypto_ed25519_fuzz_donna(void *arg)
{
  const unsigned iters = 1024;
  uint8_t msg[1024];
  unsigned i;
  (void)arg;

  tt_uint_op(iters, OP_EQ, sizeof(msg));
  crypto_rand((char*) msg, sizeof(msg));

  /* Fuzz Ed25519-donna vs ref10, alternating the implementation used to
   * generate keys/sign per iteration.
   */
  for (i = 0; i < iters; ++i) {
    const int use_donna = i & 1;
    uint8_t blinding[32];
    curve25519_keypair_t ckp;
    ed25519_keypair_t kp, kp_blind, kp_curve25519;
    ed25519_public_key_t pk, pk_blind, pk_curve25519;
    ed25519_signature_t sig, sig_blind;
    int bit = 0;

    crypto_rand((char*) blinding, sizeof(blinding));

    /* Impl. A:
     *  1. Generate a keypair.
     *  2. Blinded the keypair.
     *  3. Sign a message (unblinded).
     *  4. Sign a message (blinded).
     *  5. Generate a curve25519 keypair, and convert it to Ed25519.
     */
    ed25519_set_impl_params(use_donna);
    tt_int_op(0, OP_EQ, ed25519_keypair_generate(&kp, i&1));
    tt_int_op(0, OP_EQ, ed25519_keypair_blind(&kp_blind, &kp, blinding));
    tt_int_op(0, OP_EQ, ed25519_sign(&sig, msg, i, &kp));
    tt_int_op(0, OP_EQ, ed25519_sign(&sig_blind, msg, i, &kp_blind));

    tt_int_op(0, OP_EQ, curve25519_keypair_generate(&ckp, i&1));
    tt_int_op(0, OP_EQ, ed25519_keypair_from_curve25519_keypair(
            &kp_curve25519, &bit, &ckp));

    /* Impl. B:
     *  1. Validate the public key by rederiving it.
     *  2. Validate the blinded public key by rederiving it.
     *  3. Validate the unblinded signature (and test a invalid signature).
     *  4. Validate the blinded signature.
     *  5. Validate the public key (from Curve25519) by rederiving it.
     */
    ed25519_set_impl_params(!use_donna);
    tt_int_op(0, OP_EQ, ed25519_public_key_generate(&pk, &kp.seckey));
    tt_mem_op(pk.pubkey, OP_EQ, kp.pubkey.pubkey, 32);

    tt_int_op(0, OP_EQ, ed25519_public_blind(&pk_blind, &kp.pubkey, blinding));
    tt_mem_op(pk_blind.pubkey, OP_EQ, kp_blind.pubkey.pubkey, 32);

    tt_int_op(0, OP_EQ, ed25519_checksig(&sig, msg, i, &pk));
    sig.sig[0] ^= 15;
    tt_int_op(-1, OP_EQ, ed25519_checksig(&sig, msg, sizeof(msg), &pk));

    tt_int_op(0, OP_EQ, ed25519_checksig(&sig_blind, msg, i, &pk_blind));

    tt_int_op(0, OP_EQ, ed25519_public_key_from_curve25519_public_key(
            &pk_curve25519, &ckp.pubkey, bit));
    tt_mem_op(pk_curve25519.pubkey, OP_EQ, kp_curve25519.pubkey.pubkey, 32);
  }

 done:
  ;
}