fix idempotency issue for POST /private/orders (#6445)

3 files changed, 47 insertions, 15 deletions

diff --git a/src/backenddb/merchant-0001.sql b/src/backenddb/merchant-0001.sql
index 0adc495b..f75cbb28 100644
--- a/src/backenddb/merchant-0001.sql
+++ b/src/backenddb/merchant-0001.sql
@@ -190,6 +190,7 @@ CREATE TABLE IF NOT EXISTS merchant_orders
     REFERENCES merchant_instances (merchant_serial) ON DELETE CASCADE
   ,order_id VARCHAR NOT NULL
   ,claim_token BYTEA NOT NULL CHECK (LENGTH(claim_token)=16)
+  ,h_post_data BYTEA NOT NULL CHECK (LENGTH(h_post_data)=64)
   ,pay_deadline INT8 NOT NULL
   ,creation_time INT8 NOT NULL
   ,contract_terms BYTEA NOT NULL
@@ -199,6 +200,8 @@ COMMENT ON TABLE merchant_orders
   IS 'Orders we offered to a customer, but that have not yet been claimed';
 COMMENT ON COLUMN merchant_orders.contract_terms
   IS 'Claiming changes the contract_terms, hence we have no hash of the terms in this table';
+COMMENT ON COLUMN merchant_orders.h_post_data
+  IS 'Hash of the POST request that created this order, for idempotency checks';
 COMMENT ON COLUMN merchant_orders.claim_token
   IS 'Token optionally used to authorize the wallet to claim the order. All zeros (not NULL) if not used';
 COMMENT ON COLUMN merchant_orders.merchant_serial
diff --git a/src/backenddb/plugin_merchantdb_postgres.c b/src/backenddb/plugin_merchantdb_postgres.c
index ce87ecd7..b965b0e6 100644
--- a/src/backenddb/plugin_merchantdb_postgres.c
+++ b/src/backenddb/plugin_merchantdb_postgres.c
@@ -1103,6 +1103,7 @@ postgres_delete_order (void *cls,
  * @param order_id order id used to perform the lookup
  * @param[out] claim_token the claim token generated for the order,
  *             NULL to only test if the order exists
+ * @param[out] h_post_data set to the hash of the POST data that created the order
  * @param[out] contract_terms where to store the retrieved contract terms,
  *             NULL to only test if the order exists
  * @return transaction status
@@ -1112,6 +1113,7 @@ postgres_lookup_order (void *cls,
                        const char *instance_id,
                        const char *order_id,
                        struct TALER_ClaimTokenP *claim_token,
+                       struct GNUNET_HashCode *h_post_data,
                        json_t **contract_terms)
 {
   struct PostgresClosure *pg = cls;
@@ -1128,6 +1130,8 @@ postgres_lookup_order (void *cls,
                                &j),
     GNUNET_PQ_result_spec_auto_from_type ("claim_token",
                                           &ct),
+    GNUNET_PQ_result_spec_auto_from_type ("h_post_data",
+                                          h_post_data),
     GNUNET_PQ_result_spec_end
   };
 
@@ -1340,6 +1344,7 @@ postgres_lookup_orders (void *cls,
  * @param cls closure
  * @param instance_id identifies the instance responsible for the order
  * @param order_id alphanumeric string that uniquely identifies the proposal
+ * @param h_post_order hash of the POST data for idempotency checks
  * @param pay_deadline how long does the customer have to pay for the order
  * @param claim_token token to use for access control
  * @param contract_terms proposal data to store
@@ -1349,6 +1354,7 @@ static enum GNUNET_DB_QueryStatus
 postgres_insert_order (void *cls,
                        const char *instance_id,
                        const char *order_id,
+                       const struct GNUNET_HashCode *h_post_order,
                        struct GNUNET_TIME_Absolute pay_deadline,
                        const struct TALER_ClaimTokenP *claim_token,
                        const json_t *contract_terms)
@@ -1360,6 +1366,7 @@ postgres_insert_order (void *cls,
     GNUNET_PQ_query_param_string (order_id),
     GNUNET_PQ_query_param_absolute_time (&pay_deadline),
     GNUNET_PQ_query_param_auto_from_type (claim_token),
+    GNUNET_PQ_query_param_auto_from_type (h_post_order),
     GNUNET_PQ_query_param_absolute_time (&now),
     TALER_PQ_query_param_json (contract_terms),
     GNUNET_PQ_query_param_end
@@ -6285,6 +6292,7 @@ libtaler_plugin_merchantdb_postgres_init (void *cls)
                             "SELECT"
                             " contract_terms"
                             ",claim_token"
+                            ",h_post_data"
                             " FROM merchant_orders"
                             " WHERE merchant_orders.merchant_serial="
                             "     (SELECT merchant_serial "
@@ -7098,13 +7106,14 @@ libtaler_plugin_merchantdb_postgres_init (void *cls)
                             ",order_id"
                             ",pay_deadline"
                             ",claim_token"
+                            ",h_post_data"
                             ",creation_time"
                             ",contract_terms)"
                             " SELECT merchant_serial,"
-                            " $2, $3, $4, $5, $6"
+                            " $2, $3, $4, $5, $6, $7"
                             " FROM merchant_instances"
                             " WHERE merchant_id=$1",
-                            5),
+                            7),
     /* for postgres_unlock_inventory() */
     GNUNET_PQ_make_prepare ("unlock_inventory",
                             "DELETE"
diff --git a/src/backenddb/test_merchantdb.c b/src/backenddb/test_merchantdb.c
index afb1a380..e0ec18d4 100644
--- a/src/backenddb/test_merchantdb.c
+++ b/src/backenddb/test_merchantdb.c
@@ -1352,10 +1352,16 @@ test_insert_order (const struct InstanceData *instance,
                    const struct OrderData *order,
                    enum GNUNET_DB_QueryStatus expected_result)
 {
+  struct GNUNET_HashCode h_post;
+
+  memset (&h_post,
+          42,
+          sizeof (h_post));
   TEST_COND_RET_ON_FAIL (expected_result ==
                          plugin->insert_order (plugin->cls,
                                                instance->instance.id,
                                                order->id,
+                                               &h_post,
                                                order->pay_deadline,
                                                &order->claim_token,
                                                order->contract),
@@ -1377,11 +1383,18 @@ test_lookup_order (const struct InstanceData *instance,
 {
   struct TALER_ClaimTokenP ct;
   json_t *lookup_terms = NULL;
+  struct GNUNET_HashCode oh;
+  struct GNUNET_HashCode wh;
+
+  memset (&wh,
+          42,
+          sizeof (wh));
   if (GNUNET_DB_STATUS_SUCCESS_ONE_RESULT !=
       plugin->lookup_order (plugin->cls,
                             instance->instance.id,
                             order->id,
                             &ct,
+                            &oh,
                             &lookup_terms))
   {
     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
@@ -1390,10 +1403,12 @@ test_lookup_order (const struct InstanceData *instance,
       json_decref (lookup_terms);
     return 1;
   }
-  if ((1 != json_equal (order->contract,
-                        lookup_terms)) ||
-      (0 != GNUNET_memcmp (&order->claim_token,
-                           &ct)))
+  if ( (1 != json_equal (order->contract,
+                         lookup_terms)) ||
+       (0 != GNUNET_memcmp (&order->claim_token,
+                            &ct)) ||
+       (0 != GNUNET_memcmp (&oh,
+                            &wh)) )
   {
     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                 "Lookup order failed: incorrect order returned\n");
@@ -2002,16 +2017,21 @@ run_test_orders (struct TestOrders_Closure *cls)
   TEST_RET_ON_FAIL (test_lookup_order (&cls->instance,
                                        &cls->orders[0]));
   /* Make sure it fails correctly for nonexistent orders */
-  if (GNUNET_DB_STATUS_SUCCESS_NO_RESULTS !=
-      plugin->lookup_order (plugin->cls,
-                            cls->instance.instance.id,
-                            cls->orders[1].id,
-                            NULL,
-                            NULL))
   {
-    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
-                "Lookup order failed\n");
-    return 1;
+    struct GNUNET_HashCode unused;
+
+    if (GNUNET_DB_STATUS_SUCCESS_NO_RESULTS !=
+        plugin->lookup_order (plugin->cls,
+                              cls->instance.instance.id,
+                              cls->orders[1].id,
+                              NULL,
+                              &unused,
+                              NULL))
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                  "Lookup order failed\n");
+      return 1;
+    }
   }
   /* Test lookups on multiple orders */
   TEST_RET_ON_FAIL (test_insert_order (&cls->instance,