-towards new GET /contracts/$C_PUB hander

contrib/gana

@@ -1 +1 @@
-Subproject commit f794cafbc16ce0eae2826695235275e1e16c64db
+Subproject commit f2babbbdd477eeafb17292e16f335226ea02cb6a

src/exchange/Makefile.am

@@ -79,6 +79,7 @@ taler_exchange_transfer_LDADD = \
 taler_exchange_httpd_SOURCES = \
   taler-exchange-httpd.c taler-exchange-httpd.h \
   taler-exchange-httpd_auditors.c taler-exchange-httpd_auditors.h \
+  taler-exchange-httpd_contract.c taler-exchange-httpd_contract.h \
   taler-exchange-httpd_csr.c taler-exchange-httpd_csr \
   taler-exchange-httpd_db.c taler-exchange-httpd_db.h \
   taler-exchange-httpd_deposit.c taler-exchange-httpd_deposit.h \

src/exchange/taler-exchange-httpd.c

@@ -1,6 +1,6 @@
 /*
    This file is part of TALER
-   Copyright (C) 2014-2021 Taler Systems SA
+   Copyright (C) 2014-2022 Taler Systems SA
 
    TALER is free software; you can redistribute it and/or modify it under the
    terms of the GNU Affero General Public License as published by the Free Software
@@ -30,6 +30,7 @@
 #include <limits.h>
 #include "taler_mhd_lib.h"
 #include "taler-exchange-httpd_auditors.h"
+#include "taler-exchange-httpd_contract.h"
 #include "taler-exchange-httpd_csr.h"
 #include "taler-exchange-httpd_deposit.h"
 #include "taler-exchange-httpd_deposits_get.h"
@@ -1067,6 +1068,13 @@ handle_mhd_request (void *cls,
       .handler.get = &TEH_handler_deposits_get,
       .nargs = 4
     },
+    /* Getting purse contracts */
+    {
+      .url = "contracts",
+      .method = MHD_HTTP_METHOD_GET,
+      .handler.get = &TEH_handler_contracts_get,
+      .nargs = 1
+    },
     /* KYC endpoints */
     {
       .url = "kyc-check",

src/exchange/taler-exchange-httpd_contract.c

@@ -0,0 +1,99 @@
+/*
+  This file is part of TALER
+  Copyright (C) 2022 Taler Systems SA
+
+  TALER is free software; you can redistribute it and/or modify it under the
+  terms of the GNU Affero 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 Affero General Public License for more details.
+
+  You should have received a copy of the GNU Affero General Public License along with
+  TALER; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+*/
+/**
+ * @file taler-exchange-httpd_contract.c
+ * @brief Handle GET /contracts/$C_PUB requests
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include <gnunet/gnunet_util_lib.h>
+#include <jansson.h>
+#include <microhttpd.h>
+#include "taler_mhd_lib.h"
+#include "taler-exchange-httpd_contract.h"
+#include "taler-exchange-httpd_mhd.h"
+#include "taler-exchange-httpd_responses.h"
+
+
+MHD_RESULT
+TEH_handler_contracts_get (struct TEH_RequestContext *rc,
+                           const char *const args[1])
+{
+  struct TALER_ContractDiffiePublicP contract_pub;
+  struct TALER_PurseContractPublicKeyP purse_pub;
+  void *econtract;
+  size_t econtract_size;
+  enum GNUNET_DB_QueryStatus qs;
+  struct TALER_PurseContractSignatureP econtract_sig;
+  MHD_RESULT res;
+
+  if (GNUNET_OK !=
+      GNUNET_STRINGS_string_to_data (args[0],
+                                     strlen (args[0]),
+                                     &contract_pub,
+                                     sizeof (contract_pub)))
+  {
+    GNUNET_break_op (0);
+    return TALER_MHD_reply_with_error (rc->connection,
+                                       MHD_HTTP_BAD_REQUEST,
+                                       TALER_EC_EXCHANGE_CONTRACTS_INVALID_CONTRACT_PUB,
+                                       args[0]);
+  }
+
+  qs = TEH_plugin->select_contract (TEH_plugin->cls,
+                                    &contract_pub,
+                                    &purse_pub,
+                                    &econtract_sig,
+                                    &econtract_size,
+                                    &econtract);
+  switch (qs)
+  {
+  case GNUNET_DB_STATUS_HARD_ERROR:
+    GNUNET_break (0);
+    return TALER_MHD_reply_with_error (rc->connection,
+                                       MHD_HTTP_INTERNAL_SERVER_ERROR,
+                                       TALER_EC_GENERIC_DB_FETCH_FAILED,
+                                       "select_contract");
+  case GNUNET_DB_STATUS_SOFT_ERROR:
+    GNUNET_break (0);
+    return TALER_MHD_reply_with_error (rc->connection,
+                                       MHD_HTTP_INTERNAL_SERVER_ERROR,
+                                       TALER_EC_GENERIC_DB_FETCH_FAILED,
+                                       "select_contract");
+  case GNUNET_DB_STATUS_SUCCESS_NO_RESULTS:
+    return TALER_MHD_reply_with_error (rc->connection,
+                                       MHD_HTTP_NOT_FOUND,
+                                       TALER_EC_EXCHANGE_CONTRACTS_UNKNOWN,
+                                       NULL);
+  case GNUNET_DB_STATUS_SUCCESS_ONE_RESULT:
+    break; /* handled below */
+  }
+  res = TALER_MHD_REPLY_JSON_PACK (
+    rc->connection,
+    MHD_HTTP_OK,
+    GNUNET_JSON_pack_data_auto ("purse_pub",
+                                &purse_pub),
+    GNUNET_JSON_pack_data_auto ("econtract_sig",
+                                &econtract_sig),
+    GNUNET_JSON_pack_data_varsize ("econtract",
+                                   econtract,
+                                   econtract_size));
+  GNUNET_free (econtract);
+  return res;
+}
+
+
+/* end of taler-exchange-httpd_contract.c */

src/exchange/taler-exchange-httpd_contract.h

@@ -0,0 +1,44 @@
+/*
+  This file is part of TALER
+  Copyright (C) 2022 Taler Systems SA
+
+  TALER is free software; you can redistribute it and/or modify it under the
+  terms of the GNU Affero 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 Affero General Public License for more details.
+
+  You should have received a copy of the GNU Affero General Public License along with
+  TALER; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+*/
+/**
+ * @file taler-exchange-httpd_contract.h
+ * @brief Handle /coins/$COIN_PUB/contract requests
+ * @author Florian Dold
+ * @author Benedikt Mueller
+ * @author Christian Grothoff
+ */
+#ifndef TALER_EXCHANGE_HTTPD_CONTRACT_H
+#define TALER_EXCHANGE_HTTPD_CONTRACT_H
+
+#include <gnunet/gnunet_util_lib.h>
+#include <microhttpd.h>
+#include "taler-exchange-httpd.h"
+
+
+/**
+ * Handle a GET "/contracts/$C_PUB" request. Returns the
+ * encrypted contract.
+ *
+ * @param rc request context
+ * @param args array of additional options (length: 1, first is the contract_pub)
+ * @return MHD result code
+  */
+MHD_RESULT
+TEH_handler_contracts_get (struct TEH_RequestContext *rc,
+                           const char *const args[1]);
+
+
+#endif

src/exchange/taler-exchange-httpd_purses_create.c

@@ -404,12 +404,12 @@ create_transaction (void *cls,
     void *econtract;
     struct GNUNET_HashCode h_econtract;
 
-    qs = TEH_plugin->select_contract (TEH_plugin->cls,
+    qs = TEH_plugin->select_contract_by_purse (TEH_plugin->cls,
-                                      pcc->purse_pub,
+                                               pcc->purse_pub,
-                                      &pub_ckey,
+                                               &pub_ckey,
-                                      &econtract_sig,
+                                               &econtract_sig,
-                                      &econtract_size,
+                                               &econtract_size,
-                                      &econtract);
+                                               &econtract);
     if (qs <= 0)
     {
       if (GNUNET_DB_STATUS_SOFT_ERROR == qs)

src/exchangedb/plugin_exchangedb_postgres.c

@@ -3429,9 +3429,19 @@ prepare_statements (struct PostgresClosure *pg)
     GNUNET_PQ_make_prepare (
       "select_contract",
       "SELECT "
+      " purse_pub"
+      ",e_contract"
+      ",contract_sig"
+      " FROM contracts"
+      "   WHERE pub_ckey=$1;",
+      1),
+    /* Used in #postgres_select_contract_by_purse */
+    GNUNET_PQ_make_prepare (
+      "select_contract_by_purse",
+      "SELECT "
       " pub_ckey"
       ",e_contract"
-      // ",econtract_sig"
+      ",contract_sig"
       " FROM contracts"
       "   WHERE purse_pub=$1;",
       1),
@@ -12997,14 +13007,58 @@ postgres_insert_partner (void *cls,
  */
 static enum GNUNET_DB_QueryStatus
 postgres_select_contract (void *cls,
-                          const struct TALER_PurseContractPublicKeyP *purse_pub,
+                          const struct TALER_ContractDiffiePublicP *pub_ckey,
-                          struct TALER_ContractDiffiePublicP *pub_ckey,
+                          struct TALER_PurseContractPublicKeyP *purse_pub,
                           struct TALER_PurseContractSignatureP *econtract_sig,
                           size_t *econtract_size,
                           void **econtract)
 {
   struct PostgresClosure *pg = cls;
+  struct GNUNET_PQ_QueryParam params[] = {
+    GNUNET_PQ_query_param_auto_from_type (pub_ckey),
+    GNUNET_PQ_query_param_end
+  };
+  struct GNUNET_PQ_ResultSpec rs[] = {
+    GNUNET_PQ_result_spec_auto_from_type ("purse_pub",
+                                          purse_pub),
+    GNUNET_PQ_result_spec_auto_from_type ("contract_sig",
+                                          econtract_sig),
+    GNUNET_PQ_result_spec_variable_size ("econtract",
+                                         econtract,
+                                         econtract_size),
+    GNUNET_PQ_result_spec_end
+  };
 
+  return GNUNET_PQ_eval_prepared_singleton_select (pg->conn,
+                                                   "select_contract",
+                                                   params,
+                                                   rs);
+
+}
+
+
+/**
+ * Function called to retrieve an encrypted contract.
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param purse_pub key to lookup the contract by
+ * @param[out] pub_ckey set to the ephemeral DH used to encrypt the contract
+ * @param[out] econtract_sig set to the signature over the encrypted contract
+ * @param[out] econtract_size set to the number of bytes in @a econtract
+ * @param[out] econtract set to the encrypted contract on success, to be freed by the caller
+ * @return transaction status code
+ */
+static enum GNUNET_DB_QueryStatus
+postgres_select_contract_by_purse (void *cls,
+                                   const struct
+                                   TALER_PurseContractPublicKeyP *purse_pub,
+                                   struct TALER_ContractDiffiePublicP *pub_ckey,
+                                   struct TALER_PurseContractSignatureP *
+                                   econtract_sig,
+                                   size_t *econtract_size,
+                                   void **econtract)
+{
+  struct PostgresClosure *pg = cls;
   struct GNUNET_PQ_QueryParam params[] = {
     GNUNET_PQ_query_param_auto_from_type (purse_pub),
     GNUNET_PQ_query_param_end
@@ -13019,8 +13073,9 @@ postgres_select_contract (void *cls,
                                          econtract_size),
     GNUNET_PQ_result_spec_end
   };
+
   return GNUNET_PQ_eval_prepared_singleton_select (pg->conn,
-                                                   "select_contract",
+                                                   "select_contract_by_purse",
                                                    params,
                                                    rs);
 
@@ -13075,12 +13130,12 @@ postgres_insert_contract (
     size_t econtract_size2;
     void *econtract2;
 
-    qs = postgres_select_contract (pg,
+    qs = postgres_select_contract_by_purse (pg,
-                                   purse_pub,
+                                            purse_pub,
-                                   &pub_ckey2,
+                                            &pub_ckey2,
-                                   &esig2,
+                                            &esig2,
-                                   &econtract_size2,
+                                            &econtract_size2,
-                                   &econtract2);
+                                            &econtract2);
     if (GNUNET_DB_STATUS_SUCCESS_ONE_RESULT != qs)
     {
       GNUNET_break (0);
@@ -13797,6 +13852,8 @@ libtaler_plugin_exchangedb_postgres_init (void *cls)
     = &postgres_insert_contract;
   plugin->select_contract
     = &postgres_select_contract;
+  plugin->select_contract_by_purse
+    = &postgres_select_contract_by_purse;
   plugin->insert_purse_request
     = &postgres_insert_purse_request;
   plugin->select_purse_request

src/include/taler_exchangedb_plugin.h

@@ -4443,6 +4443,26 @@ struct TALER_EXCHANGEDB_Plugin
                      bool *in_conflict);
 
 
+  /**
+   * Function called to retrieve an encrypted contract.
+   *
+   * @param cls the @e cls of this struct with the plugin-specific state
+   * @param pub_ckey set to the ephemeral DH used to encrypt the contract, key used to lookup the contract by
+   * @param[out] purse_pub public key of the purse of the contract
+   * @param[out] econtract_sig set to the signature over the encrypted contract
+   * @param[out] econtract_size set to the number of bytes in @a econtract
+   * @param[out] econtract set to the encrypted contract on success, to be freed by the caller
+   * @return transaction status code
+   */
+  enum GNUNET_DB_QueryStatus
+  (*select_contract)(
+    void *cls,
+    const struct TALER_ContractDiffiePublicP *pub_ckey,
+    struct TALER_PurseContractPublicKeyP *purse_pub,
+    struct TALER_PurseContractSignatureP *econtract_sig,
+    size_t *econtract_size,
+    void **econtract);
+
   /**
    * Function called to retrieve an encrypted contract.
    *
@@ -4455,12 +4475,13 @@ struct TALER_EXCHANGEDB_Plugin
    * @return transaction status code
    */
   enum GNUNET_DB_QueryStatus
-  (*select_contract)(void *cls,
+  (*select_contract_by_purse)(
-                     const struct TALER_PurseContractPublicKeyP *purse_pub,
+    void *cls,
-                     struct TALER_ContractDiffiePublicP *pub_ckey,
+    const struct TALER_PurseContractPublicKeyP *purse_pub,
-                     struct TALER_PurseContractSignatureP *econtract_sig,
+    struct TALER_ContractDiffiePublicP *pub_ckey,
-                     size_t *econtract_size,
+    struct TALER_PurseContractSignatureP *econtract_sig,
-                     void **econtract);
+    size_t *econtract_size,
+    void **econtract);
 
 
   /**