big rename fest related to #6067 API renaming

1 files changed, 512 insertions, 0 deletions

diff --git a/src/lib/exchange_api_refreshes_reveal.c b/src/lib/exchange_api_refreshes_reveal.c
new file mode 100644
index 000000000..96aafbda8
--- /dev/null
+++ b/src/lib/exchange_api_refreshes_reveal.c
@@ -0,0 +1,512 @@
+/*
+  This file is part of TALER
+  Copyright (C) 2015-2020 Taler Systems SA
+
+  TALER is free software; you can redistribute it and/or modify it under the
+  terms of the GNU General Public License as published by the Free Software
+  Foundation; either version 3, or (at your option) any later version.
+
+  TALER is distributed in the hope that it will be useful, but WITHOUT ANY
+  WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+  A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License along with
+  TALER; see the file COPYING.  If not, see
+  <http://www.gnu.org/licenses/>
+*/
+/**
+ * @file lib/exchange_api_refreshes_reveal.c
+ * @brief Implementation of the /refreshes/$RCH/reveal requests
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include <jansson.h>
+#include <microhttpd.h> /* just for HTTP status codes */
+#include <gnunet/gnunet_util_lib.h>
+#include <gnunet/gnunet_json_lib.h>
+#include <gnunet/gnunet_curl_lib.h>
+#include "taler_json_lib.h"
+#include "taler_exchange_service.h"
+#include "exchange_api_handle.h"
+#include "taler_signatures.h"
+#include "exchange_api_curl_defaults.h"
+#include "exchange_api_refresh_common.h"
+
+
+/**
+ * @brief A /refreshes/$RCH/reveal Handle
+ */
+struct TALER_EXCHANGE_RefreshesRevealHandle
+{
+
+  /**
+   * The connection to exchange this request handle will use
+   */
+  struct TALER_EXCHANGE_Handle *exchange;
+
+  /**
+   * The url for this request.
+   */
+  char *url;
+
+  /**
+   * Context for #TEH_curl_easy_post(). Keeps the data that must
+   * persist for Curl to make the upload.
+   */
+  struct TALER_CURL_PostContext ctx;
+
+  /**
+   * Handle for the request.
+   */
+  struct GNUNET_CURL_Job *job;
+
+  /**
+   * Function to call with the result.
+   */
+  TALER_EXCHANGE_RefreshesRevealCallback reveal_cb;
+
+  /**
+   * Closure for @e reveal_cb.
+   */
+  void *reveal_cb_cls;
+
+  /**
+   * Actual information about the melt operation.
+   */
+  struct MeltData *md;
+
+  /**
+   * The index selected by the exchange in cut-and-choose to not be revealed.
+   */
+  uint16_t noreveal_index;
+
+};
+
+
+/**
+ * We got a 200 OK response for the /refreshes/$RCH/reveal operation.
+ * Extract the coin signatures and return them to the caller.
+ * The signatures we get from the exchange is for the blinded value.
+ * Thus, we first must unblind them and then should verify their
+ * validity.
+ *
+ * If everything checks out, we return the unblinded signatures
+ * to the application via the callback.
+ *
+ * @param rrh operation handle
+ * @param json reply from the exchange
+ * @param[out] sigs array of length `num_fresh_coins`, initialized to cointain RSA signatures
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR on errors
+ */
+static int
+refresh_reveal_ok (struct TALER_EXCHANGE_RefreshesRevealHandle *rrh,
+                   const json_t *json,
+                   struct TALER_DenominationSignature *sigs)
+{
+  json_t *jsona;
+  struct GNUNET_JSON_Specification outer_spec[] = {
+    GNUNET_JSON_spec_json ("ev_sigs", &jsona),
+    GNUNET_JSON_spec_end ()
+  };
+
+  if (GNUNET_OK !=
+      GNUNET_JSON_parse (json,
+                         outer_spec,
+                         NULL, NULL))
+  {
+    GNUNET_break_op (0);
+    return GNUNET_SYSERR;
+  }
+  if (! json_is_array (jsona))
+  {
+    /* We expected an array of coins */
+    GNUNET_break_op (0);
+    GNUNET_JSON_parse_free (outer_spec);
+    return GNUNET_SYSERR;
+  }
+  if (rrh->md->num_fresh_coins != json_array_size (jsona))
+  {
+    /* Number of coins generated does not match our expectation */
+    GNUNET_break_op (0);
+    GNUNET_JSON_parse_free (outer_spec);
+    return GNUNET_SYSERR;
+  }
+  for (unsigned int i = 0; i<rrh->md->num_fresh_coins; i++)
+  {
+    const struct TALER_PlanchetSecretsP *fc;
+    struct TALER_DenominationPublicKey *pk;
+    json_t *jsonai;
+    struct GNUNET_CRYPTO_RsaSignature *blind_sig;
+    struct TALER_CoinSpendPublicKeyP coin_pub;
+    struct GNUNET_HashCode coin_hash;
+    struct GNUNET_JSON_Specification spec[] = {
+      GNUNET_JSON_spec_rsa_signature ("ev_sig", &blind_sig),
+      GNUNET_JSON_spec_end ()
+    };
+    struct TALER_FreshCoin coin;
+
+    fc = &rrh->md->fresh_coins[rrh->noreveal_index][i];
+    pk = &rrh->md->fresh_pks[i];
+    jsonai = json_array_get (jsona, i);
+    GNUNET_assert (NULL != jsonai);
+
+    if (GNUNET_OK !=
+        GNUNET_JSON_parse (jsonai,
+                           spec,
+                           NULL, NULL))
+    {
+      GNUNET_break_op (0);
+      GNUNET_JSON_parse_free (outer_spec);
+      return GNUNET_SYSERR;
+    }
+
+    /* needed to verify the signature, and we didn't store it earlier,
+       hence recomputing it here... */
+    GNUNET_CRYPTO_eddsa_key_get_public (&fc->coin_priv.eddsa_priv,
+                                        &coin_pub.eddsa_pub);
+    GNUNET_CRYPTO_hash (&coin_pub.eddsa_pub,
+                        sizeof (struct GNUNET_CRYPTO_EcdsaPublicKey),
+                        &coin_hash);
+    if (GNUNET_OK !=
+        TALER_planchet_to_coin (pk,
+                                blind_sig,
+                                fc,
+                                &coin_hash,
+                                &coin))
+    {
+      GNUNET_break_op (0);
+      GNUNET_CRYPTO_rsa_signature_free (blind_sig);
+      GNUNET_JSON_parse_free (outer_spec);
+      return GNUNET_SYSERR;
+    }
+    GNUNET_CRYPTO_rsa_signature_free (blind_sig);
+    sigs[i] = coin.sig;
+  }
+  GNUNET_JSON_parse_free (outer_spec);
+  return GNUNET_OK;
+}
+
+
+/**
+ * Function called when we're done processing the
+ * HTTP /refreshes/$RCH/reveal request.
+ *
+ * @param cls the `struct TALER_EXCHANGE_RefreshHandle`
+ * @param response_code HTTP response code, 0 on error
+ * @param response parsed JSON result, NULL on error
+ */
+static void
+handle_refresh_reveal_finished (void *cls,
+                                long response_code,
+                                const void *response)
+{
+  struct TALER_EXCHANGE_RefreshesRevealHandle *rrh = cls;
+  const json_t *j = response;
+
+  rrh->job = NULL;
+  switch (response_code)
+  {
+  case 0:
+    break;
+  case MHD_HTTP_OK:
+    {
+      struct TALER_DenominationSignature sigs[rrh->md->num_fresh_coins];
+      int ret;
+
+      memset (sigs, 0, sizeof (sigs));
+      ret = refresh_reveal_ok (rrh,
+                               j,
+                               sigs);
+      if (GNUNET_OK != ret)
+      {
+        response_code = 0;
+      }
+      else
+      {
+        rrh->reveal_cb (rrh->reveal_cb_cls,
+                        MHD_HTTP_OK,
+                        TALER_EC_NONE,
+                        rrh->md->num_fresh_coins,
+                        rrh->md->fresh_coins[rrh->noreveal_index],
+                        sigs,
+                        j);
+        rrh->reveal_cb = NULL;
+      }
+      for (unsigned int i = 0; i<rrh->md->num_fresh_coins; i++)
+        if (NULL != sigs[i].rsa_signature)
+          GNUNET_CRYPTO_rsa_signature_free (sigs[i].rsa_signature);
+    }
+    break;
+  case MHD_HTTP_BAD_REQUEST:
+    /* This should never happen, either us or the exchange is buggy
+       (or API version conflict); just pass JSON reply to the application */
+    break;
+  case MHD_HTTP_CONFLICT:
+    /* Nothing really to verify, exchange says our reveal is inconsitent
+       with our commitment, so either side is buggy; we
+       should pass the JSON reply to the application */
+    break;
+  case MHD_HTTP_INTERNAL_SERVER_ERROR:
+    /* Server had an internal issue; we should retry, but this API
+       leaves this to the application */
+    break;
+  default:
+    /* unexpected response code */
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                "Unexpected response code %u\n",
+                (unsigned int) response_code);
+    GNUNET_break (0);
+    response_code = 0;
+    break;
+  }
+  if (NULL != rrh->reveal_cb)
+    rrh->reveal_cb (rrh->reveal_cb_cls,
+                    response_code,
+                    TALER_JSON_get_error_code (j),
+                    0,
+                    NULL,
+                    NULL,
+                    j);
+  TALER_EXCHANGE_refreshes_reveal_cancel (rrh);
+}
+
+
+/**
+ * Submit a /refresh/reval request to the exchange and get the exchange's
+ * response.
+ *
+ * This API is typically used by a wallet.  Note that to ensure that
+ * no money is lost in case of hardware failures, the provided
+ * arguments should have been committed to persistent storage
+ * prior to calling this function.
+ *
+ * @param exchange the exchange handle; the exchange must be ready to operate
+ * @param refresh_data_length size of the @a refresh_data (returned
+ *        in the `res_size` argument from #TALER_EXCHANGE_refresh_prepare())
+ * @param refresh_data the refresh data as returned from
+          #TALER_EXCHANGE_refresh_prepare())
+ * @param noreveal_index response from the exchange to the
+ *        #TALER_EXCHANGE_melt() invocation
+ * @param reveal_cb the callback to call with the final result of the
+ *        refresh operation
+ * @param reveal_cb_cls closure for the above callback
+ * @return a handle for this request; NULL if the argument was invalid.
+ *         In this case, neither callback will be called.
+ */
+struct TALER_EXCHANGE_RefreshesRevealHandle *
+TALER_EXCHANGE_refreshes_reveal (struct TALER_EXCHANGE_Handle *exchange,
+                                 size_t refresh_data_length,
+                                 const char *refresh_data,
+                                 uint32_t noreveal_index,
+                                 TALER_EXCHANGE_RefreshesRevealCallback
+                                 reveal_cb,
+                                 void *reveal_cb_cls)
+{
+  struct TALER_EXCHANGE_RefreshesRevealHandle *rrh;
+  json_t *transfer_privs;
+  json_t *new_denoms_h;
+  json_t *coin_evs;
+  json_t *reveal_obj;
+  json_t *link_sigs;
+  CURL *eh;
+  struct GNUNET_CURL_Context *ctx;
+  struct MeltData *md;
+  struct TALER_TransferPublicKeyP transfer_pub;
+  char arg_str[sizeof (struct TALER_RefreshCommitmentP) * 2 + 32];
+
+  if (noreveal_index >= TALER_CNC_KAPPA)
+  {
+    /* We check this here, as it would be really bad to below just
+       disclose all the transfer keys. Note that this error should
+       have been caught way earlier when the exchange replied, but maybe
+       we had some internal corruption that changed the value... */
+    GNUNET_break (0);
+    return NULL;
+  }
+  if (GNUNET_YES !=
+      TEAH_handle_is_ready (exchange))
+  {
+    GNUNET_break (0);
+    return NULL;
+  }
+  md = TALER_EXCHANGE_deserialize_melt_data_ (refresh_data,
+                                              refresh_data_length);
+  if (NULL == md)
+  {
+    GNUNET_break (0);
+    return NULL;
+  }
+
+  /* now transfer_pub */
+  GNUNET_CRYPTO_ecdhe_key_get_public (
+    &md->melted_coin.transfer_priv[noreveal_index].ecdhe_priv,
+    &transfer_pub.ecdhe_pub);
+
+  /* now new_denoms */
+  GNUNET_assert (NULL != (new_denoms_h = json_array ()));
+  GNUNET_assert (NULL != (coin_evs = json_array ()));
+  GNUNET_assert (NULL != (link_sigs = json_array ()));
+  for (unsigned int i = 0; i<md->num_fresh_coins; i++)
+  {
+    struct GNUNET_HashCode denom_hash;
+    struct TALER_PlanchetDetail pd;
+
+    GNUNET_CRYPTO_rsa_public_key_hash (md->fresh_pks[i].rsa_public_key,
+                                       &denom_hash);
+    GNUNET_assert (0 ==
+                   json_array_append_new (new_denoms_h,
+                                          GNUNET_JSON_from_data_auto (
+                                            &denom_hash)));
+
+    if (GNUNET_OK !=
+        TALER_planchet_prepare (&md->fresh_pks[i],
+                                &md->fresh_coins[noreveal_index][i],
+                                &pd))
+    {
+      /* This should have been noticed during the preparation stage. */
+      GNUNET_break (0);
+      json_decref (new_denoms_h);
+      json_decref (coin_evs);
+      return NULL;
+    }
+    GNUNET_assert (0 ==
+                   json_array_append_new (coin_evs,
+                                          GNUNET_JSON_from_data (pd.coin_ev,
+                                                                 pd.coin_ev_size)));
+
+    /* compute link signature */
+    {
+      struct TALER_CoinSpendSignatureP link_sig;
+      struct TALER_LinkDataPS ldp;
+
+      ldp.purpose.size = htonl (sizeof (ldp));
+      ldp.purpose.purpose = htonl (TALER_SIGNATURE_WALLET_COIN_LINK);
+      ldp.h_denom_pub = denom_hash;
+      GNUNET_CRYPTO_eddsa_key_get_public (&md->melted_coin.coin_priv.eddsa_priv,
+                                          &ldp.old_coin_pub.eddsa_pub);
+      ldp.transfer_pub = transfer_pub;
+      GNUNET_CRYPTO_hash (pd.coin_ev,
+                          pd.coin_ev_size,
+                          &ldp.coin_envelope_hash);
+      GNUNET_assert (GNUNET_OK ==
+                     GNUNET_CRYPTO_eddsa_sign (
+                       &md->melted_coin.coin_priv.eddsa_priv,
+                       &ldp.purpose,
+                       &link_sig.eddsa_signature));
+      GNUNET_assert (0 ==
+                     json_array_append_new (link_sigs,
+                                            GNUNET_JSON_from_data_auto (
+                                              &link_sig)));
+    }
+
+    GNUNET_free (pd.coin_ev);
+  }
+
+  /* build array of transfer private keys */
+  GNUNET_assert (NULL != (transfer_privs = json_array ()));
+  for (unsigned int j = 0; j<TALER_CNC_KAPPA; j++)
+  {
+    if (j == noreveal_index)
+    {
+      /* This is crucial: exclude the transfer key for the
+   noreval index! */
+      continue;
+    }
+    GNUNET_assert (0 ==
+                   json_array_append_new (transfer_privs,
+                                          GNUNET_JSON_from_data_auto (
+                                            &md->melted_coin.transfer_priv[j])));
+  }
+
+  /* build main JSON request */
+  reveal_obj = json_pack ("{s:o, s:o, s:o, s:o, s:o}",
+                          "transfer_pub",
+                          GNUNET_JSON_from_data_auto (&transfer_pub),
+                          "transfer_privs",
+                          transfer_privs,
+                          "link_sigs",
+                          link_sigs,
+                          "new_denoms_h",
+                          new_denoms_h,
+                          "coin_evs",
+                          coin_evs);
+  if (NULL == reveal_obj)
+  {
+    GNUNET_break (0);
+    return NULL;
+  }
+
+  {
+    char pub_str[sizeof (struct TALER_RefreshCommitmentP) * 2];
+    char *end;
+
+    end = GNUNET_STRINGS_data_to_string (&md->rc,
+                                         sizeof (struct
+                                                 TALER_RefreshCommitmentP),
+                                         pub_str,
+                                         sizeof (pub_str));
+    *end = '\0';
+    GNUNET_snprintf (arg_str,
+                     sizeof (arg_str),
+                     "/refreshes/%s/reveal",
+                     pub_str);
+  }
+  /* finally, we can actually issue the request */
+  rrh = GNUNET_new (struct TALER_EXCHANGE_RefreshesRevealHandle);
+  rrh->exchange = exchange;
+  rrh->noreveal_index = noreveal_index;
+  rrh->reveal_cb = reveal_cb;
+  rrh->reveal_cb_cls = reveal_cb_cls;
+  rrh->md = md;
+  rrh->url = TEAH_path_to_url (rrh->exchange,
+                               arg_str);
+
+  eh = TEL_curl_easy_get (rrh->url);
+  if (GNUNET_OK !=
+      TALER_curl_easy_post (&rrh->ctx,
+                            eh,
+                            reveal_obj))
+  {
+    GNUNET_break (0);
+    curl_easy_cleanup (eh);
+    json_decref (reveal_obj);
+    GNUNET_free (rrh->url);
+    GNUNET_free (rrh);
+    return NULL;
+  }
+  json_decref (reveal_obj);
+  ctx = TEAH_handle_to_context (rrh->exchange);
+  rrh->job = GNUNET_CURL_job_add2 (ctx,
+                                   eh,
+                                   rrh->ctx.headers,
+                                   &handle_refresh_reveal_finished,
+                                   rrh);
+  return rrh;
+}
+
+
+/**
+ * Cancel a refresh reveal request.  This function cannot be used
+ * on a request handle if the callback was already invoked.
+ *
+ * @param rrh the refresh reval handle
+ */
+void
+TALER_EXCHANGE_refreshes_reveal_cancel (struct
+                                        TALER_EXCHANGE_RefreshesRevealHandle *
+                                        rrh)
+{
+  if (NULL != rrh->job)
+  {
+    GNUNET_CURL_job_cancel (rrh->job);
+    rrh->job = NULL;
+  }
+  GNUNET_free (rrh->url);
+  TALER_curl_easy_post_finished (&rrh->ctx);
+  TALER_EXCHANGE_free_melt_data_ (rrh->md); /* does not free 'md' itself */
+  GNUNET_free (rrh->md);
+  GNUNET_free (rrh);
+}
+
+
+/* exchange_api_refreshes_reveal.c */