-eliminate redundant hash operation on link signatures

2021-12-25 15:39:01 +01:00 · 2021-12-25 15:39:01 +01:00 · f6ecb6c895
commit f6ecb6c895
parent 84c9adf5a6
6 changed files with 34 additions and 22 deletions
--- a/src/exchange/taler-exchange-httpd_refreshes_reveal.c
+++ b/src/exchange/taler-exchange-httpd_refreshes_reveal.c
@ -297,11 +297,14 @@ resolve_refreshes_reveal_denominations (struct MHD_Connection *connection,
 {
  unsigned int num_fresh_coins = json_array_size (new_denoms_h_json);
  /* We know num_fresh_coins is bounded by #MAX_FRESH_COINS, so this is safe */
+  // FIXME: messy to have so many arrays -- and then
+  // later we copy them around! Avoidable!?!
  const struct TEH_DenominationKey *dks[num_fresh_coins];
  struct TALER_DenominationHash dk_h[num_fresh_coins];
  struct TALER_RefreshCoinData rcds[num_fresh_coins];
  struct TALER_CoinSpendSignatureP link_sigs[num_fresh_coins];
  struct TALER_BlindedDenominationSignature ev_sigs[num_fresh_coins];
+  struct TALER_BlindedCoinHash h_blind_ev[num_fresh_coins];
  MHD_RESULT ret;
  struct TEH_KeyStateHandle *ksh;
  uint64_t melt_serial_id;
@ -398,6 +401,9 @@ resolve_refreshes_reveal_denominations (struct MHD_Connection *connection,
        GNUNET_free (rcds[j].coin_ev);
      return (GNUNET_NO == res) ? MHD_YES : MHD_NO;
    }
+    GNUNET_CRYPTO_hash (rcd->coin_ev,
+                        rcd->coin_ev_size,
+                        &h_blind_ev[i].hash);
    rcd->dk = &dks[i]->denom_pub;
  }

@ -468,8 +474,7 @@ resolve_refreshes_reveal_denominations (struct MHD_Connection *connection,
        TALER_wallet_link_verify (
          &dk_h[i],
          &rctx->gamma_tp,
-          rcds[i].coin_ev,
-          rcds[i].coin_ev_size,
+          &h_blind_ev[i],
          &rctx->melt.session.coin.coin_pub,
          &link_sigs[i]))
    {
@ -529,6 +534,7 @@ resolve_refreshes_reveal_denominations (struct MHD_Connection *connection,
      rrc->coin_ev = rcds[i].coin_ev;
      rrc->coin_ev_size = rcds[i].coin_ev_size;
      rrc->coin_sig = ev_sigs[i];
+      rrc->coin_envelope_hash = h_blind_ev[i];
    }
    qs = TEH_plugin->insert_refresh_reveal (TEH_plugin->cls,
                                            melt_serial_id,
--- a/src/exchangedb/plugin_exchangedb_postgres.c
+++ b/src/exchangedb/plugin_exchangedb_postgres.c
@ -906,6 +906,7 @@ prepare_statements (struct PostgresClosure *pg)
      "SELECT "
      " rrc.freshcoin_index"
      ",denom.denom_pub_hash"
+      ",rrc.h_coin_ev"
      ",rrc.link_sig"
      ",rrc.coin_ev"
      ",rrc.ev_sig"
@ -6113,8 +6114,7 @@ postgres_insert_refresh_reveal (
      GNUNET_PQ_query_param_auto_from_type (tp),
      GNUNET_PQ_query_param_fixed_size (
        tprivs,
-        num_tprivs
-        * sizeof (struct TALER_TransferPrivateKeyP)),
+        num_tprivs * sizeof (struct TALER_TransferPrivateKeyP)),
      GNUNET_PQ_query_param_end
    };

@ -6199,6 +6199,8 @@ add_revealed_coins (void *cls,
                                              &rrc->h_denom_pub),
        GNUNET_PQ_result_spec_auto_from_type ("link_sig",
                                              &rrc->orig_coin_link_sig),
+        GNUNET_PQ_result_spec_auto_from_type ("h_coin_ev",
+                                              &rrc->coin_envelope_hash),
        GNUNET_PQ_result_spec_variable_size ("coin_ev",
                                             (void **) &rrc->coin_ev,
                                             &rrc->coin_ev_size),
--- a/src/include/taler_crypto_lib.h
+++ b/src/include/taler_crypto_lib.h
@ -1788,8 +1788,7 @@ TALER_wallet_link_sign (const struct TALER_DenominationHash *h_denom_pub,
 *
 * @param h_denom_pub hash of the denomiantion public key of the new coin
 * @param transfer_pub transfer public key
- * @param coin_ev coin envelope
- * @param coin_ev_size number of bytes in @a coin_ev
+ * @param h_coin_ev hash of the coin envelope
 * @param old_coin_pub old coin key that the link signature is for
 * @param coin_sig resulting signature
 * @return #GNUNET_OK if the signature is valid
@ -1798,8 +1797,7 @@ enum GNUNET_GenericReturnValue
 TALER_wallet_link_verify (
  const struct TALER_DenominationHash *h_denom_pub,
  const struct TALER_TransferPublicKeyP *transfer_pub,
-  const void *coin_ev,
-  size_t coin_ev_size,
+  const struct TALER_BlindedCoinHash *h_coin_ev,
  const struct TALER_CoinSpendPublicKeyP *old_coin_pub,
  const struct TALER_CoinSpendSignatureP *coin_sig);

--- a/src/include/taler_exchangedb_plugin.h
+++ b/src/include/taler_exchangedb_plugin.h
@ -1635,6 +1635,16 @@ struct TALER_EXCHANGEDB_RefreshRevealedCoin
   */
  struct TALER_CoinSpendSignatureP orig_coin_link_sig;

+  /**
+   * Hash of the blinded new coin, that is @e coin_ev.
+   */
+  struct TALER_BlindedCoinHash coin_envelope_hash;
+
+  /**
+   * Signature generated by the exchange over the coin (in blinded format).
+   */
+  struct TALER_BlindedDenominationSignature coin_sig;
+
  /**
   * Blinded message to be signed (in envelope), with @e coin_env_size bytes.
   */
@ -1645,10 +1655,6 @@ struct TALER_EXCHANGEDB_RefreshRevealedCoin
   */
  size_t coin_ev_size;

-  /**
-   * Signature generated by the exchange over the coin (in blinded format).
-   */
-  struct TALER_BlindedDenominationSignature coin_sig;
 };


@ -2972,7 +2978,7 @@ struct TALER_EXCHANGEDB_Plugin


  /**
-   * Lookup in the database for the @a num_freshcoins coins that we
+   * Lookup in the database for the fresh coins that we
   * created in the given refresh operation.
   *
   * @param cls the @e cls of this struct with the plugin-specific state
--- a/src/lib/exchange_api_link.c
+++ b/src/lib/exchange_api_link.c
@ -138,6 +138,7 @@ parse_link_coin (const struct TALER_EXCHANGE_LinkHandle *lh,
    struct TALER_PlanchetDetail pd;
    struct TALER_CoinPubHash c_hash;
    struct TALER_CoinSpendPublicKeyP old_coin_pub;
+    struct TALER_BlindedCoinHash coin_envelope_hash;

    GNUNET_CRYPTO_eddsa_key_get_public (&lh->coin_priv.eddsa_priv,
                                        &old_coin_pub.eddsa_pub);
@ -151,11 +152,14 @@ parse_link_coin (const struct TALER_EXCHANGE_LinkHandle *lh,
      GNUNET_JSON_parse_free (spec);
      return GNUNET_SYSERR;
    }
+    GNUNET_CRYPTO_hash (pd.coin_ev,
+                        pd.coin_ev_size,
+                        &coin_envelope_hash.hash);
+
    if (GNUNET_OK !=
        TALER_wallet_link_verify (&pd.denom_pub_hash,
                                  trans_pub,
-                                  pd.coin_ev,
-                                  pd.coin_ev_size,
+                                  &coin_envelope_hash,
                                  &old_coin_pub,
                                  &link_sig))
    {
--- a/src/util/wallet_signatures.c
+++ b/src/util/wallet_signatures.c
@ -133,9 +133,7 @@ enum GNUNET_GenericReturnValue
 TALER_wallet_link_verify (
  const struct TALER_DenominationHash *h_denom_pub,
  const struct TALER_TransferPublicKeyP *transfer_pub,
-  // FIXME: consider passing hash!
-  const void *coin_ev,
-  size_t coin_ev_size,
+  const struct TALER_BlindedCoinHash *h_coin_ev,
  const struct TALER_CoinSpendPublicKeyP *old_coin_pub,
  const struct TALER_CoinSpendSignatureP *coin_sig)
 {
@ -143,12 +141,10 @@ TALER_wallet_link_verify (
    .purpose.size = htonl (sizeof (ldp)),
    .purpose.purpose = htonl (TALER_SIGNATURE_WALLET_COIN_LINK),
    .h_denom_pub = *h_denom_pub,
-    .transfer_pub = *transfer_pub
+    .transfer_pub = *transfer_pub,
+    .coin_envelope_hash = *h_coin_ev
  };

-  GNUNET_CRYPTO_hash (coin_ev,
-                      coin_ev_size,
-                      &ldp.coin_envelope_hash.hash);
  return
    GNUNET_CRYPTO_eddsa_verify (TALER_SIGNATURE_WALLET_COIN_LINK,
                                &ldp,