parse tokens in pay handler

1 files changed, 130 insertions, 0 deletions

diff --git a/src/backend/taler-merchant-httpd_post-orders-ID-pay.c b/src/backend/taler-merchant-httpd_post-orders-ID-pay.c
index 14edfd55..2bdf891f 100644
--- a/src/backend/taler-merchant-httpd_post-orders-ID-pay.c
+++ b/src/backend/taler-merchant-httpd_post-orders-ID-pay.c
@@ -25,6 +25,8 @@
  * @author Florian Dold
  */
 #include "platform.h"
+#include <gnunet/gnunet_json_lib.h>
+#include <stdint.h>
 #include <taler/taler_dbevents.h>
 #include <taler/taler_signatures.h>
 #include <taler/taler_json_lib.h>
@@ -46,6 +48,12 @@
 #define MAX_COIN_ALLOWED_COINS 1024
 
 /**
+ * TODO: What is a good value for this?
+ * Maximum number of tokens that we allow per transaction
+ */
+#define MAX_TOKEN_ALLOWED_TOKENS 128
+
+/**
  * How often do we ask the exchange again about our
  * KYC status? Very rarely, as if the user actively
  * changes it, we should usually notice anyway.
@@ -202,6 +210,36 @@ struct DepositConfirmation
 
 };
 
+struct TokenUseConfirmation
+{
+
+  /**
+   * Slug of the token family this token belongs to.
+   */
+  char *slug;
+
+  /**
+   * Signature on the deposit request made using the token private key.
+   */
+  struct TALER_TokenUseSignature sig;
+
+  /**
+   * Public key of the token.
+   */
+  struct TALER_TokenUsePublicKey pub;
+
+  /**
+   * Unblinded signature done by the merchant.
+   */
+  struct TALER_TokenIssueSignature unblinded_sig;
+
+  /**
+   * Hash of the token issue public key associated with this token.
+   */
+  struct TALER_TokenIssuePublicKeyHash h_issue;
+
+};
+
 
 /**
  * Information kept during a pay request for each exchange.
@@ -274,6 +312,11 @@ struct PayContext
   struct DepositConfirmation *dc;
 
   /**
+   * Array with @e tokens_cnt tokens we are using.
+   */
+  struct TokenUseConfirmation *tokens;
+
+  /**
    * MHD connection to return to
    */
   struct MHD_Connection *connection;
@@ -302,6 +345,11 @@ struct PayContext
   struct MHD_Response *response;
 
   /**
+   * Index of selected choice in the @e contract_terms choices array.
+   */
+  int64_t choice_index;
+
+  /**
    * Our contract (or NULL if not available).
    */
   json_t *contract_terms;
@@ -421,6 +469,12 @@ struct PayContext
   size_t coins_cnt;
 
   /**
+   * Number of tokens this payment uses.  Length
+   * of the @e tokens array.
+   */
+  size_t tokens_cnt;
+
+  /**
    * Number of exchanges involved in the payment. Length
    * of the @e eg array.
    */
@@ -2405,6 +2459,7 @@ phase_parse_pay (struct PayContext *pc)
 {
   const char *session_id = NULL;
   const json_t *coins;
+  const json_t *tokens;
   struct GNUNET_JSON_Specification spec[] = {
     GNUNET_JSON_spec_array_const ("coins",
                                   &coins),
@@ -2412,6 +2467,14 @@ phase_parse_pay (struct PayContext *pc)
       GNUNET_JSON_spec_string ("session_id",
                                &session_id),
       NULL),
+    GNUNET_JSON_spec_mark_optional (
+      GNUNET_JSON_spec_int64 ("choice_index",
+                              &pc->choice_index),
+      NULL),
+    GNUNET_JSON_spec_mark_optional (
+      GNUNET_JSON_spec_array_const ("tokens",
+                                    &tokens),
+      NULL),
     GNUNET_JSON_spec_end ()
   };
 
@@ -2456,10 +2519,26 @@ phase_parse_pay (struct PayContext *pc)
     return;
   }
 
+  pc->tokens_cnt = json_array_size (tokens);
+  if (pc->tokens_cnt > MAX_TOKEN_ALLOWED_TOKENS)
+  {
+    GNUNET_break_op (0);
+    pay_end (pc,
+             TALER_MHD_reply_with_error (
+               pc->connection,
+               MHD_HTTP_BAD_REQUEST,
+               TALER_EC_GENERIC_PARAMETER_MALFORMED,
+               "'tokens' array too long"));
+    return;
+  }
+
   /* note: 1 coin = 1 deposit confirmation expected */
   pc->dc = GNUNET_new_array (pc->coins_cnt,
                              struct DepositConfirmation);
 
+  pc->tokens = GNUNET_new_array (pc->tokens_cnt,
+                                 struct TokenUseConfirmation);
+
   /* This loop populates the array 'dc' in 'pc' */
   {
     unsigned int coins_index;
@@ -2574,6 +2653,57 @@ phase_parse_pay (struct PayContext *pc)
       }
     }
   }
+
+  /* This look populates the array 'tokens' in 'pc' */
+  {
+    unsigned int tokens_index;
+    json_t *token;
+
+    json_array_foreach (tokens, tokens_index, token)
+    {
+      struct TokenUseConfirmation *tuc = &pc->tokens[tokens_index];
+      struct GNUNET_JSON_Specification ispec[] = {
+        GNUNET_JSON_spec_fixed_auto ("token_sig",
+                                     &tuc->sig),
+        GNUNET_JSON_spec_fixed_auto ("token_pub",
+                                     &tuc->pub),
+        // TALER_JSON_spec_denom_sig ("ub_sig",
+        //                            &tuc->unblinded_sig),
+        GNUNET_JSON_spec_fixed_auto ("h_issue",
+                                     &tuc->h_issue),
+        GNUNET_JSON_spec_end ()
+      };
+      enum GNUNET_GenericReturnValue res;
+
+      res = TALER_MHD_parse_json_data (pc->connection,
+                                       token,
+                                       ispec);
+      if (GNUNET_YES != res)
+      {
+        GNUNET_break_op (0);
+        pay_end (pc,
+                 (GNUNET_NO == res)
+                 ? MHD_YES
+                 : MHD_NO);
+        return;
+      }
+      for (unsigned int j = 0; j<tokens_index; j++)
+      {
+        if (0 ==
+            GNUNET_memcmp (&tuc->pub,
+                           &pc->tokens[j].pub))
+        {
+          GNUNET_break_op (0);
+          pay_end (pc,
+                   TALER_MHD_reply_with_error (pc->connection,
+                                               MHD_HTTP_BAD_REQUEST,
+                                               TALER_EC_GENERIC_PARAMETER_MALFORMED,
+                                               "duplicate token in list"));
+          return;
+        }
+      }
+    }
+  }
   pc->phase = PP_CHECK_CONTRACT;
 }