use age commitment parser from libtalerexchange

1 files changed, 59 insertions, 89 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 bbd74822..2e78c10d 100644
--- a/src/backend/taler-merchant-httpd_post-orders-ID-pay.c
+++ b/src/backend/taler-merchant-httpd_post-orders-ID-pay.c
@@ -129,6 +129,9 @@ struct DepositConfirmation
    */
   struct TALER_AgeAttestation minimum_age_sig;
 
+  /* true, if no field "minimum_age_sig" was found in the JSON blob */
+  bool no_minimum_age_sig;
+
   /**
    * If a minimum age was required (i. e. pc->minimum_age is large enough),
    * this is the age commitment (i. e. age mask and vector of EdDSA public
@@ -136,7 +139,21 @@ struct DepositConfirmation
    * SHA256 hash of the mask and the vector of public keys was bound to the
    * key.
    */
-  struct TALER_AgeCommitment *age_commitment;
+  struct TALER_AgeCommitment age_commitment;
+
+  /* true, if no field "age_commitment" was found in the JSON blob */
+  bool no_age_commitment;
+
+  /**
+   * In the case that somebody pays with a coin that is age restricted, but the
+   * the contract did not ask for a minimum age, the merchant still needs the
+   * hash of the age commitment in order to a) verify the coin and b) deposit
+   * it.
+   */
+  struct TALER_AgeCommitmentHash h_age_commitment;
+
+  /* true, if no field "h_age_commitment" was found in the JSON blob */
+  bool no_h_age_commitment;
 
   /**
    * Age mask in the denomination that defines the age groups.  Only
@@ -1069,7 +1086,6 @@ process_pay_with_exchange (
   struct PayContext *pc = cls;
   struct TMH_HandlerContext *hc = pc->hc;
   const struct TALER_EXCHANGE_Keys *keys;
-  struct TALER_AgeCommitmentHash h_age_commitment = {0};
 
   (void) payto_uri;
   pc->fo = NULL;
@@ -1116,6 +1132,8 @@ process_pay_with_exchange (
     enum TALER_ErrorCode ec;
     unsigned int http_status;
     bool age_verification_required = false;
+    struct TALER_AgeCommitmentHash ach = {0};
+    struct TALER_AgeCommitmentHash *achp = NULL;
 
     if (NULL != dc->dh)
       continue; /* we were here before (can happen due to
@@ -1199,15 +1217,15 @@ process_pay_with_exchange (
     {
       unsigned int code = 0;
 
-      if (NULL == dc->age_commitment)
+      if (dc->no_age_commitment)
       {
         code = TALER_EC_MERCHANT_POST_ORDERS_ID_PAY_AGE_COMMITMENT_MISSING;
         goto AGE_FAIL;
       }
 
-      dc->age_commitment->mask = denom_details->key.age_mask;
-      if ((dc->age_commitment->num + 1) !=
-          __builtin_popcount (dc->age_commitment->mask.bits))
+      dc->age_commitment.mask = denom_details->key.age_mask;
+      if ((dc->age_commitment.num + 1) !=
+          __builtin_popcount (dc->age_commitment.mask.bits))
       {
         code =
           TALER_EC_MERCHANT_POST_ORDERS_ID_PAY_AGE_COMMITMENT_SIZE_MISMATCH;
@@ -1216,7 +1234,7 @@ process_pay_with_exchange (
 
       if (GNUNET_OK !=
           TALER_age_commitment_verify (
-            dc->age_commitment,
+            &dc->age_commitment,
             pc->minimum_age,
             &dc->minimum_age_sig))
         code = TALER_EC_MERCHANT_POST_ORDERS_ID_PAY_AGE_VERIFICATION_FAILED;
@@ -1236,8 +1254,10 @@ AGE_FAIL:
 
       /* Age restriction successfully verified!
        * Calculate the hash of the age commitment. */
-      TALER_age_commitment_hash (dc->age_commitment,
-                                 &h_age_commitment);
+      TALER_age_commitment_hash (&dc->age_commitment,
+                                 &ach);
+
+      achp = &ach;
     }
 
     dc->deposit_fee = denom_details->fees.deposit;
@@ -1251,8 +1271,7 @@ AGE_FAIL:
                                      pc->wm->payto_uri,
                                      &pc->wm->wire_salt,
                                      &pc->h_contract_terms,
-                                     age_verification_required ?
-                                     &h_age_commitment: NULL,
+                                     achp,
                                      NULL, /* FIXME oec: extension json blob */
                                      &dc->coin_pub,
                                      &dc->ub_sig,
@@ -2042,11 +2061,12 @@ parse_pay (struct PayContext *pc)
   {
     unsigned int coins_index;
     json_t *coin;
+
     json_array_foreach (coins, coins_index, coin)
     {
       struct DepositConfirmation *dc = &pc->dc[coins_index];
       const char *exchange_url;
-      json_t *age_commitment = NULL;
+      bool no_minimum_age_sig;
       struct GNUNET_JSON_Specification ispec[] = {
         GNUNET_JSON_spec_fixed_auto ("coin_sig",
                                      &dc->coin_sig),
@@ -2061,14 +2081,22 @@ parse_pay (struct PayContext *pc)
                                 &dc->amount_with_fee),
         GNUNET_JSON_spec_string ("exchange_url",
                                  &exchange_url),
+        /* if a minimum age was required, the minimum_age_sig and
+         * age_commitment must be provided */
         GNUNET_JSON_spec_mark_optional (
           GNUNET_JSON_spec_fixed_auto ("minimum_age_sig",
                                        &dc->minimum_age_sig),
-          NULL),
+          &no_minimum_age_sig),
+        GNUNET_JSON_spec_mark_optional (
+          TALER_JSON_spec_age_commitment ("age_commitment",
+                                          &dc->age_commitment),
+          &dc->no_age_commitment),
+        /* if minimum age was not required, but coin with age restriction set
+         * was used, h_age_commitment must be provided. */
         GNUNET_JSON_spec_mark_optional (
-          GNUNET_JSON_spec_json ("age_commitment",
-                                 &age_commitment),
-          NULL),
+          GNUNET_JSON_spec_fixed_auto ("h_age_commitment",
+                                       &dc->h_age_commitment),
+          &dc->no_h_age_commitment),
         GNUNET_JSON_spec_end ()
       };
       enum GNUNET_GenericReturnValue res;
@@ -2119,12 +2147,21 @@ parse_pay (struct PayContext *pc)
               : GNUNET_SYSERR;
       }
 
+      // Check the consistency of the (potential) age restriction
+      // information.
       {
-        bool has_commitment = (NULL != age_commitment) &&
-                              json_is_array (age_commitment);
-        bool has_sig = ! GNUNET_is_zero_ (&dc->minimum_age_sig,
-                                          sizeof(dc->minimum_age_sig));
-        if (has_sig != has_commitment)
+        char *error = NULL;
+
+        if (0 < dc->pc->minimum_age &&
+            dc->no_minimum_age_sig &&
+            dc->no_age_commitment)
+          error = "required: 'mininum_age_sig' and 'age_commitment'";
+
+        if (! dc->no_age_commitment &&
+            dc->no_h_age_commitment)
+          error = "only one allowed: 'age_commitment' vs. 'h_age_commitment'";
+
+        if (NULL != error)
         {
           GNUNET_break_op (0);
           GNUNET_JSON_parse_free (spec);
@@ -2133,69 +2170,11 @@ parse_pay (struct PayContext *pc)
                     pc->connection,
                     MHD_HTTP_BAD_REQUEST,
                     TALER_EC_GENERIC_PARAMETER_MALFORMED,
-                    "inconsistency: 'mininum_age_sig' vs. 'age_commitment'")
+                    error)
                   )
               ? GNUNET_NO
               : GNUNET_SYSERR;
         }
-
-        /* Parse the AgeCommitment, i. e. the public keys */
-        if (has_commitment)
-        {
-          json_t *pk;
-          unsigned int idx;
-          size_t num = json_array_size (age_commitment);
-
-          /* Sanity check the amount of AgeCommitment's public keys.  The
-           * actual check will be performed once we now the denominations. */
-          if (32 <= num)
-          {
-            GNUNET_break_op (0);
-            GNUNET_JSON_parse_free (spec);
-            return (MHD_YES ==
-                    TALER_MHD_reply_with_error (pc->connection,
-                                                MHD_HTTP_BAD_REQUEST,
-                                                TALER_EC_GENERIC_PARAMETER_MALFORMED,
-                                                "'age_commitment' too large"
-                                                ))
-                ? GNUNET_NO
-                : GNUNET_SYSERR;
-          }
-
-          dc->age_commitment = GNUNET_new (struct TALER_AgeCommitment);
-          dc->age_commitment->num = num;
-          dc->age_commitment->keys =
-            GNUNET_new_array (num,
-                              struct TALER_AgeCommitmentPublicKeyP);
-          /* Note that dc->age_commitment.mask will be set later, based on
-           * the actual denomination. */
-
-          json_array_foreach (age_commitment, idx, pk) {
-            struct GNUNET_JSON_Specification pkspec[] = {
-              GNUNET_JSON_spec_fixed_auto (
-                NULL,
-                &dc->age_commitment->keys[idx].pub),
-              GNUNET_JSON_spec_end ()
-            };
-
-            if (GNUNET_OK !=
-                GNUNET_JSON_parse (pk,
-                                   pkspec,
-                                   NULL, NULL))
-            {
-              GNUNET_break_op (0);
-              GNUNET_JSON_parse_free (spec);
-              return (MHD_YES ==
-                      TALER_MHD_reply_with_error (
-                        pc->connection,
-                        MHD_HTTP_BAD_REQUEST,
-                        TALER_EC_GENERIC_PARAMETER_MALFORMED,
-                        "age_commitment"))
-                  ? GNUNET_NO
-                  : GNUNET_SYSERR;
-            }
-          }
-        }
       }
     }
   }
@@ -2538,15 +2517,6 @@ check_contract (struct PayContext *pc)
     pc->wm = wm;
   }
 
-  if (0 < pc->minimum_age)
-  {
-    /* TODO oec: check
-     * 1. denomination are age restricted
-     * 2. consume their mask
-     * 3. valididate minimum age
-     */
-  }
-
   return GNUNET_OK;
 }