work on POST /orders/ID/claim (unfinished)

1 files changed, 166 insertions, 138 deletions

diff --git a/src/backend/taler-merchant-httpd_post-orders-ID-claim.c b/src/backend/taler-merchant-httpd_post-orders-ID-claim.c
index 47207131..e58a73c5 100644
--- a/src/backend/taler-merchant-httpd_post-orders-ID-claim.c
+++ b/src/backend/taler-merchant-httpd_post-orders-ID-claim.c
@@ -1,6 +1,6 @@
 /*
   This file is part of TALER
-  (C) 2014, 2015, 2016, 2018 Taler Systems SA
+  (C) 2014, 2015, 2016, 2018, 2020 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
@@ -18,18 +18,16 @@
 */
 
 /**
- * @file backend/taler-merchant-httpd_proposal.c
- * @brief HTTP serving layer mainly intended to communicate
- * with the frontend
+ * @file backend/taler-merchant-httpd_post-orders-ID-claim.c
+ * @brief headers for POST /orders/$ID/claim handler
  * @author Marcello Stanisci
+ * @author Christian Grothoff
  */
 #include "platform.h"
 #include <jansson.h>
 #include <taler/taler_signatures.h>
 #include <taler/taler_json_lib.h>
-#include "taler-merchant-httpd.h"
-#include "taler-merchant-httpd_auditors.h"
-#include "taler-merchant-httpd_exchanges.h"
+#include "taler-merchant-httpd_post-orders-ID-claim.h"
 
 
 /**
@@ -37,163 +35,193 @@
  */
 #define MAX_RETRIES 3
 
+
 /**
- * Manage a GET /proposal request. Query the db and returns the
- * proposal's data related to the transaction id given as the URL's
- * parameter.
+ * Run transaction to claim @a order_id for @a nonce.
  *
- * Binds the proposal to a nonce.
+ * @param instance_id instance to claim order at
+ * @param order_id order to claim
+ * @param nonce nonce to use for the claim
+ * @param[out] contract_terms set to the resulting contract terms
+ *             (for any non-negative result;
+ * @return transaction status code
+ *         #GNUNET_DB_STATUS_SUCCESS_NO_RESULTS if the order was claimed by a different
+ *         nonce (@a contract_terms set to non-NULL)
+ *                OR if the order is is unknown (@a contract_terms is NULL)
+ *         #GNUNET_DB_STATUS_SUCCESS_ONE_RESULT if the order was successfully claimed
+ */
+static enum GNUNET_DB_QueryStatus
+claim_order (const char *instance_id,
+             const char *order_id,
+             const char *nonce,
+             json_t **contract_terms)
+{
+  enum GNUNET_DB_QueryStatus qs;
+
+  if (GNUNET_OK !=
+      TMH_db->start (TMH_db->cls,
+                     "claim order"))
+  {
+    GNUNET_break (0);
+    return GNUNET_DB_STATUS_HARD_ERROR;
+  }
+  qs = TMH_db->lookup_contract_terms (TMH_db->cls,
+                                      order_id,
+                                      instance_id,
+                                      contract_terms);
+  if (0 > qs)
+  {
+    TMH_db->rollback (TMH_db->cls);
+    return qs;
+  }
+
+  if (GNUNET_DB_STATUS_SUCCESS_NO_RESULTS == qs)
+  {
+    /* see if we have this order in our table of unclaimed orders */
+    qs = TMH_db->lookup_order (TMH_db->cls,
+                               instance_id,
+                               order_id,
+                               contract_terms);
+    if (0 >= qs)
+    {
+      TMH_db->rollback (TMH_db->cls);
+      return qs;
+    }
+    GNUNET_assert (NULL != contract_terms);
+    GNUNET_assert (0 ==
+                   json_object_set_new (*contract_terms,
+                                        "nonce",
+                                        json_string (nonce)));
+    qs = TMH_db->insert_contract_terms (TMH_db->cls,
+                                        instance_id,
+                                        order_id,
+                                        *contract_terms);
+    if (0 > qs)
+    {
+      TMH_db->rollback (TMH_db->cls);
+      json_decref (*contract_terms);
+      *contract_terms = NULL;
+      return qs;
+    }
+    // FIXME: should we remove the ORDER from the order table here?
+    qs = TMH_db->commit (TMH_db->cls);
+    if (0 > qs)
+      return qs;
+    return GNUNET_DB_STATUS_SUCCESS_ONE_RESULT;
+  }
+  else
+  {
+    const char *stored_nonce;
+
+    TMH_db->rollback (TMH_db->cls);
+    GNUNET_assert (NULL != *contract_terms);
+    stored_nonce
+      = json_string_value (json_object_get (*contract_terms,
+                                            "nonce"));
+    if (NULL == stored_nonce)
+    {
+      /* this should not be possible: contract_terms should always
+         have a nonce! */
+      GNUNET_break (0);
+      return GNUNET_DB_STATUS_HARD_ERROR;
+    }
+    if (0 != strcmp (stored_nonce,
+                     nonce))
+    {
+      return GNUNET_DB_STATUS_SUCCESS_NO_RESULTS;
+    }
+    return GNUNET_DB_STATUS_SUCCESS_ONE_RESULT;
+  }
+}
+
+
+/**
+ * Manage a POST /orders/$ID/claim request.  Allows the client to
+ * claim the order (unless already claims) and creates the respective
+ * contract.  Returns the contract terms.
  *
  * @param rh context of the handler
  * @param connection the MHD connection to handle
- * @param[in,out] connection_cls the connection's closure (can be updated)
- * @param upload_data upload data
- * @param[in,out] upload_data_size number of bytes (left) in @a upload_data
- * @param mi merchant backend instance, never NULL
+ * @param[in,out] hc context with further information about the request
  * @return MHD result code
  */
 MHD_RESULT
-MH_handler_proposal_lookup (struct TMH_RequestHandler *rh,
-                            struct MHD_Connection *connection,
-                            void **connection_cls,
-                            const char *upload_data,
-                            size_t *upload_data_size,
-                            struct MerchantInstance *mi)
+TMH_post_orders_ID_claim (const struct TMH_RequestHandler *rh,
+                          struct MHD_Connection *connection,
+                          struct TMH_HandlerContext *hc)
 {
-  const char *order_id;
+  const char *order_id = hc->infix;
   const char *nonce;
   enum GNUNET_DB_QueryStatus qs;
   json_t *contract_terms;
-  struct GNUNET_CRYPTO_EddsaSignature merchant_sig;
-  const char *stored_nonce;
 
-  order_id = MHD_lookup_connection_value (connection,
-                                          MHD_GET_ARGUMENT_KIND,
-                                          "order_id");
-  if (NULL == order_id)
-    return TALER_MHD_reply_with_error (connection,
-                                       MHD_HTTP_BAD_REQUEST,
-                                       TALER_EC_PARAMETER_MISSING,
-                                       "order_id");
-  nonce = MHD_lookup_connection_value (connection,
-                                       MHD_GET_ARGUMENT_KIND,
-                                       "nonce");
-  if (NULL == nonce)
-    return TALER_MHD_reply_with_error (connection,
-                                       MHD_HTTP_BAD_REQUEST,
-                                       TALER_EC_PARAMETER_MISSING,
-                                       "nonce");
-  db->preflight (db->cls);
-  qs = db->find_contract_terms (db->cls,
-                                &contract_terms,
-                                order_id,
-                                &mi->pubkey);
-  if (0 > qs)
-  {
-    /* single, read-only SQL statements should never cause
-       serialization problems */
-    GNUNET_break (GNUNET_DB_STATUS_SOFT_ERROR != qs);
-    /* Always report on hard error as well to enable diagnostics */
-    GNUNET_break (GNUNET_DB_STATUS_HARD_ERROR == qs);
-    return TALER_MHD_reply_with_error (connection,
-                                       MHD_HTTP_INTERNAL_SERVER_ERROR,
-                                       TALER_EC_PROPOSAL_LOOKUP_DB_ERROR,
-                                       "An error occurred while retrieving proposal data from db");
-  }
-  if (GNUNET_DB_STATUS_SUCCESS_NO_RESULTS == qs)
   {
-    struct GNUNET_TIME_Absolute timestamp;
     struct GNUNET_JSON_Specification spec[] = {
-      GNUNET_JSON_spec_absolute_time ("timestamp", &timestamp),
+      GNUNET_JSON_spec_string ("nonce",
+                               &nonce),
       GNUNET_JSON_spec_end ()
     };
     enum GNUNET_GenericReturnValue res;
 
-    db->preflight (db->cls);
-    qs = db->find_order (db->cls,
-                         &contract_terms,
-                         order_id,
-                         &mi->pubkey);
-    if (GNUNET_DB_STATUS_SUCCESS_NO_RESULTS == qs)
-    {
-      return TALER_MHD_reply_with_error (connection,
-                                         MHD_HTTP_NOT_FOUND,
-                                         TALER_EC_PROPOSAL_LOOKUP_NOT_FOUND,
-                                         "unknown order id");
-    }
-    GNUNET_assert (NULL != contract_terms);
-    json_object_set_new (contract_terms,
-                         "nonce",
-                         json_string (nonce));
-
-    /* extract fields we need to sign separately */
     res = TALER_MHD_parse_json_data (connection,
-                                     contract_terms,
+                                     hc->request_body,
                                      spec);
+    /* json is malformed */
     if (GNUNET_NO == res)
     {
+      GNUNET_break_op (0);
       return MHD_YES;
     }
+    /* other internal errors might have occurred */
     if (GNUNET_SYSERR == res)
-    {
-      return TALER_MHD_reply_with_error (connection,
-                                         MHD_HTTP_INTERNAL_SERVER_ERROR,
-                                         TALER_EC_PROPOSAL_ORDER_PARSE_ERROR,
-                                         "Impossible to parse the order");
-    }
-
-    for (unsigned int i = 0; i<MAX_RETRIES; i++)
-    {
-      db->preflight (db->cls);
-      qs = db->insert_contract_terms (db->cls,
-                                      order_id,
-                                      &mi->pubkey,
-                                      timestamp,
-                                      contract_terms);
-      if (GNUNET_DB_STATUS_SOFT_ERROR != qs)
-        break;
-    }
-    if (0 > qs)
-    {
-      /* Special report if retries insufficient */
-      GNUNET_break (GNUNET_DB_STATUS_SOFT_ERROR != qs);
-      /* Always report on hard error as well to enable diagnostics */
-      GNUNET_break (GNUNET_DB_STATUS_HARD_ERROR == qs);
       return TALER_MHD_reply_with_error (connection,
-                                         MHD_HTTP_INTERNAL_SERVER_ERROR,
-                                         TALER_EC_PROPOSAL_STORE_DB_ERROR,
-                                         "db error: could not store this proposal's data into db");
-    }
-    // FIXME: now we can delete (merchant_pub, order_id) from the merchant_orders table
+                                         MHD_HTTP_BAD_REQUEST,
+                                         TALER_EC_PARAMETER_MISSING,
+                                         "nonce");
   }
-
-  GNUNET_assert (NULL != contract_terms);
-
-  stored_nonce
-    = json_string_value (json_object_get (contract_terms,
-                                          "nonce"));
-
-  if (NULL == stored_nonce)
+  contract_terms = NULL;
+  for (unsigned int i = 0; i<MAX_RETRIES; i++)
   {
-    GNUNET_break (0);
-    return TALER_MHD_reply_with_error (connection,
-                                       MHD_HTTP_INTERNAL_SERVER_ERROR,
-                                       TALER_EC_PROPOSAL_ORDER_PARSE_ERROR,
-                                       "existing proposal has no nonce");
+    TMH_db->preflight (TMH_db->cls);
+    qs = claim_order (hc->instance->settings.id,
+                      order_id,
+                      nonce,
+                      &contract_terms);
+    if (GNUNET_DB_STATUS_SOFT_ERROR != qs)
+      break;
   }
-
-  if (0 != strcmp (stored_nonce,
-                   nonce))
+  switch (qs)
   {
+  case GNUNET_DB_STATUS_HARD_ERROR:
+    return TALER_MHD_reply_with_error (connection,
+                                       MHD_HTTP_INTERNAL_SERVER_ERROR,
+                                       TALER_EC_ORDERS_CLAIM_HARD_DB_ERROR,
+                                       "Failed to run DB transaction to claim order");
+  case GNUNET_DB_STATUS_SOFT_ERROR:
+    return TALER_MHD_reply_with_error (connection,
+                                       MHD_HTTP_INTERNAL_SERVER_ERROR,
+                                       TALER_EC_ORDERS_CLAIM_SOFT_DB_ERROR,
+                                       "Failed to serialize DB transaction to claim order");
+  case GNUNET_DB_STATUS_SUCCESS_NO_RESULTS:
+    if (NULL == contract_terms)
+      return TALER_MHD_reply_with_error (connection,
+                                         MHD_HTTP_NOT_FOUND,
+                                         TALER_EC_ORDERS_CLAIM_NOT_FOUND,
+                                         "unknown order id");
+    /* already claimed! */
+    json_decref (contract_terms);
     return TALER_MHD_reply_with_error (connection,
-                                       MHD_HTTP_BAD_REQUEST,
-                                       TALER_EC_PROPOSAL_LOOKUP_NOT_FOUND,
-                                       "mismatched nonce");
+                                       MHD_HTTP_CONFLICT,
+                                       TALER_EC_ORDERS_ALREADY_CLAIMED,
+                                       "order already claimed");
+  case GNUNET_DB_STATUS_SUCCESS_ONE_RESULT:
+    GNUNET_assert (NULL != contract_terms);
+    break; /* Good! return signature (below) */
   }
 
-
   /* create proposal signature */
   {
+    struct GNUNET_CRYPTO_EddsaSignature merchant_sig;
     struct TALER_ProposalDataPS pdps = {
       .purpose.purpose = htonl (TALER_SIGNATURE_MERCHANT_CONTRACT),
       .purpose.size = htonl (sizeof (pdps))
@@ -210,19 +238,19 @@ MH_handler_proposal_lookup (struct TMH_RequestHandler *rh,
                                          "Could not hash order");
     }
 
-    GNUNET_CRYPTO_eddsa_sign (&mi->privkey.eddsa_priv,
+    GNUNET_CRYPTO_eddsa_sign (&hc->instance->merchant_priv.eddsa_priv,
                               &pdps,
                               &merchant_sig);
+    return TALER_MHD_reply_json_pack (connection,
+                                      MHD_HTTP_OK,
+                                      "{ s:o, s:o }",
+                                      "contract_terms",
+                                      contract_terms,
+                                      "sig",
+                                      GNUNET_JSON_from_data_auto (
+                                        &merchant_sig));
   }
-  return TALER_MHD_reply_json_pack (connection,
-                                    MHD_HTTP_OK,
-                                    "{ s:o, s:o }",
-                                    "contract_terms",
-                                    contract_terms,
-                                    "sig",
-                                    GNUNET_JSON_from_data_auto (
-                                      &merchant_sig));
 }
 
 
-/* end of taler-merchant-httpd_proposal.c */
+/* end of taler-merchant-httpd_post-orders-ID-claim.c */