code cleanup, fixing misc. memory leaks in the process

13 files changed, 89 insertions, 155 deletions

diff --git a/src/exchange/taler-exchange-httpd_age-withdraw_reveal.c b/src/exchange/taler-exchange-httpd_age-withdraw_reveal.c
index 776c0d8d..d604632d 100644
--- a/src/exchange/taler-exchange-httpd_age-withdraw_reveal.c
+++ b/src/exchange/taler-exchange-httpd_age-withdraw_reveal.c
@@ -984,14 +984,18 @@ TEH_handler_age_withdraw_reveal (
   MHD_RESULT result = MHD_NO;
   enum GNUNET_GenericReturnValue ret = GNUNET_SYSERR;
   struct AgeRevealContext actx = {0};
-  json_t *j_denoms_h;
-  json_t *j_coin_evs;
-  json_t *j_disclosed_coin_secrets;
+  const json_t *j_denoms_h;
+  const json_t *j_coin_evs;
+  const json_t *j_disclosed_coin_secrets;
   struct GNUNET_JSON_Specification spec[] = {
-    GNUNET_JSON_spec_fixed_auto ("reserve_pub", &actx.reserve_pub),
-    GNUNET_JSON_spec_json ("denoms_h", &j_denoms_h),
-    GNUNET_JSON_spec_json ("coin_evs", &j_coin_evs),
-    GNUNET_JSON_spec_json ("disclosed_coin_secrets", &j_disclosed_coin_secrets),
+    GNUNET_JSON_spec_fixed_auto ("reserve_pub",
+                                 &actx.reserve_pub),
+    GNUNET_JSON_spec_array_const ("denoms_h",
+                                  &j_denoms_h),
+    GNUNET_JSON_spec_array_const ("coin_evs",
+                                  &j_coin_evs),
+    GNUNET_JSON_spec_array_const ("disclosed_coin_secrets",
+                                  &j_disclosed_coin_secrets),
     GNUNET_JSON_spec_end ()
   };
 
@@ -1010,7 +1014,8 @@ TEH_handler_age_withdraw_reveal (
 
   do {
     /* Extract denominations, blinded and disclosed coins */
-    if (GNUNET_OK != parse_age_withdraw_reveal_json (
+    if (GNUNET_OK !=
+        parse_age_withdraw_reveal_json (
           rc->connection,
           j_denoms_h,
           j_coin_evs,
@@ -1020,7 +1025,8 @@ TEH_handler_age_withdraw_reveal (
       break;
 
     /* Find original commitment */
-    if (GNUNET_OK != find_original_commitment (
+    if (GNUNET_OK !=
+        find_original_commitment (
           rc->connection,
           &actx.ach,
           &actx.reserve_pub,
@@ -1029,7 +1035,8 @@ TEH_handler_age_withdraw_reveal (
       break;
 
     /* Ensure validity of denoms and the sum of amounts and fees */
-    if (GNUNET_OK != are_denominations_valid (
+    if (GNUNET_OK !=
+        are_denominations_valid (
           rc->connection,
           actx.num_coins,
           actx.denoms_h,
@@ -1043,7 +1050,8 @@ TEH_handler_age_withdraw_reveal (
 
     /* Verify the computed h_commitment equals the committed one and that coins
      * have a maximum age group corresponding max_age (age-mask dependent) */
-    if (GNUNET_OK != verify_commitment_and_max_age (
+    if (GNUNET_OK !=
+        verify_commitment_and_max_age (
           rc->connection,
           &actx.commitment.h_commitment,
           actx.commitment.max_age,
@@ -1056,7 +1064,8 @@ TEH_handler_age_withdraw_reveal (
       break;
 
     /* Finally, sign and persist the coins */
-    if (GNUNET_OK != sign_and_finalize_age_withdraw (
+    if (GNUNET_OK !=
+        sign_and_finalize_age_withdraw (
           rc->connection,
           &actx.commitment.h_commitment,
           actx.num_coins,
@@ -1068,7 +1077,6 @@ TEH_handler_age_withdraw_reveal (
   } while(0);
 
   age_reveal_context_free (&actx);
-  GNUNET_JSON_parse_free (spec);
   return result;
 }
 
diff --git a/src/exchange/taler-exchange-httpd_aml-decision.c b/src/exchange/taler-exchange-httpd_aml-decision.c
index 2830e54e..c1439adc 100644
--- a/src/exchange/taler-exchange-httpd_aml-decision.c
+++ b/src/exchange/taler-exchange-httpd_aml-decision.c
@@ -74,7 +74,7 @@ struct DecisionContext
   /**
    * KYC requirements imposed, NULL for none.
    */
-  json_t *kyc_requirements;
+  const json_t *kyc_requirements;
 
 };
 
@@ -261,8 +261,8 @@ TEH_handler_post_aml_decision (
     GNUNET_JSON_spec_uint32 ("new_state",
                              &new_state32),
     GNUNET_JSON_spec_mark_optional (
-      GNUNET_JSON_spec_json ("kyc_requirements",
-                             &dc.kyc_requirements),
+      GNUNET_JSON_spec_array_const ("kyc_requirements",
+                                    &dc.kyc_requirements),
       NULL),
     GNUNET_JSON_spec_end ()
   };
@@ -306,17 +306,6 @@ TEH_handler_post_aml_decision (
     size_t index;
     json_t *elem;
 
-    if (! json_is_array (dc.kyc_requirements))
-    {
-      GNUNET_break_op (0);
-      GNUNET_JSON_parse_free (spec);
-      return TALER_MHD_reply_with_error (
-        connection,
-        MHD_HTTP_BAD_REQUEST,
-        TALER_EC_GENERIC_PARAMETER_MALFORMED,
-        "kyc_requirements must be an array");
-    }
-
     json_array_foreach (dc.kyc_requirements, index, elem)
     {
       const char *val;
@@ -324,7 +313,6 @@ TEH_handler_post_aml_decision (
       if (! json_is_string (elem))
       {
         GNUNET_break_op (0);
-        GNUNET_JSON_parse_free (spec);
         return TALER_MHD_reply_with_error (
           connection,
           MHD_HTTP_BAD_REQUEST,
@@ -336,7 +324,6 @@ TEH_handler_post_aml_decision (
           TALER_KYCLOGIC_check_satisfiable (val))
       {
         GNUNET_break_op (0);
-        GNUNET_JSON_parse_free (spec);
         return TALER_MHD_reply_with_error (
           connection,
           MHD_HTTP_BAD_REQUEST,
@@ -357,11 +344,9 @@ TEH_handler_post_aml_decision (
                                 &make_aml_decision,
                                 &dc))
     {
-      GNUNET_JSON_parse_free (spec);
       return mhd_ret;
     }
   }
-  GNUNET_JSON_parse_free (spec);
   return TALER_MHD_reply_static (
     connection,
     MHD_HTTP_NO_CONTENT,
diff --git a/src/exchange/taler-exchange-httpd_batch-deposit.c b/src/exchange/taler-exchange-httpd_batch-deposit.c
index d000c454..488f85ab 100644
--- a/src/exchange/taler-exchange-httpd_batch-deposit.c
+++ b/src/exchange/taler-exchange-httpd_batch-deposit.c
@@ -545,7 +545,7 @@ TEH_handler_batch_deposit (struct TEH_RequestContext *rc,
 {
   struct MHD_Connection *connection = rc->connection;
   struct BatchDepositContext dc;
-  json_t *coins;
+  const json_t *coins;
   bool no_refund_deadline = true;
   bool no_policy_json = true;
   struct GNUNET_JSON_Specification spec[] = {
@@ -557,8 +557,8 @@ TEH_handler_batch_deposit (struct TEH_RequestContext *rc,
                                  &dc.merchant_pub),
     GNUNET_JSON_spec_fixed_auto ("h_contract_terms",
                                  &dc.h_contract_terms),
-    GNUNET_JSON_spec_json ("coins",
-                           &coins),
+    GNUNET_JSON_spec_array_const ("coins",
+                                  &coins),
     GNUNET_JSON_spec_mark_optional (
       GNUNET_JSON_spec_json ("policy",
                              &dc.policy_json),
diff --git a/src/exchange/taler-exchange-httpd_batch-withdraw.c b/src/exchange/taler-exchange-httpd_batch-withdraw.c
index c3065e1d..9d7d64cb 100644
--- a/src/exchange/taler-exchange-httpd_batch-withdraw.c
+++ b/src/exchange/taler-exchange-httpd_batch-withdraw.c
@@ -843,10 +843,10 @@ TEH_handler_batch_withdraw (struct TEH_RequestContext *rc,
     .reserve_pub = reserve_pub,
     .rc = rc
   };
-  json_t *planchets;
+  const json_t *planchets;
   struct GNUNET_JSON_Specification spec[] = {
-    GNUNET_JSON_spec_json ("planchets",
-                           &planchets),
+    GNUNET_JSON_spec_array_const ("planchets",
+                                  &planchets),
     GNUNET_JSON_spec_end ()
   };
 
@@ -862,20 +862,17 @@ TEH_handler_batch_withdraw (struct TEH_RequestContext *rc,
     if (GNUNET_OK != res)
       return (GNUNET_SYSERR == res) ? MHD_NO : MHD_YES;
   }
-  if ( (! json_is_array (planchets)) ||
-       (0 == json_array_size (planchets)) )
+  wc.planchets_length = json_array_size (planchets);
+  if (0 == wc.planchets_length)
   {
-    GNUNET_JSON_parse_free (spec);
     GNUNET_break_op (0);
     return TALER_MHD_reply_with_error (rc->connection,
                                        MHD_HTTP_BAD_REQUEST,
                                        TALER_EC_GENERIC_PARAMETER_MALFORMED,
                                        "planchets");
   }
-  wc.planchets_length = json_array_size (planchets);
   if (wc.planchets_length > TALER_MAX_FRESH_COINS)
   {
-    GNUNET_JSON_parse_free (spec);
     GNUNET_break_op (0);
     return TALER_MHD_reply_with_error (rc->connection,
                                        MHD_HTTP_BAD_REQUEST,
@@ -901,7 +898,6 @@ TEH_handler_batch_withdraw (struct TEH_RequestContext *rc,
       TALER_blinded_planchet_free (&pc->blinded_planchet);
       TALER_blinded_denom_sig_free (&pc->collectable.sig);
     }
-    GNUNET_JSON_parse_free (spec);
     return ret;
   }
 }
diff --git a/src/exchange/taler-exchange-httpd_csr.c b/src/exchange/taler-exchange-httpd_csr.c
index 29f83c2c..3ceb319c 100644
--- a/src/exchange/taler-exchange-httpd_csr.c
+++ b/src/exchange/taler-exchange-httpd_csr.c
@@ -39,12 +39,12 @@ TEH_handler_csr_melt (struct TEH_RequestContext *rc,
 {
   struct TALER_RefreshMasterSecretP rms;
   unsigned int csr_requests_num;
-  json_t *csr_requests;
+  const json_t *csr_requests;
   struct GNUNET_JSON_Specification spec[] = {
     GNUNET_JSON_spec_fixed_auto ("rms",
                                  &rms),
-    GNUNET_JSON_spec_json ("nks",
-                           &csr_requests),
+    GNUNET_JSON_spec_array_const ("nks",
+                                  &csr_requests),
     GNUNET_JSON_spec_end ()
   };
   enum TALER_ErrorCode ec;
@@ -65,7 +65,7 @@ TEH_handler_csr_melt (struct TEH_RequestContext *rc,
   if ( (TALER_MAX_FRESH_COINS <= csr_requests_num) ||
        (0 == csr_requests_num) )
   {
-    GNUNET_JSON_parse_free (spec);
+    GNUNET_break_op (0);
     return TALER_MHD_reply_with_error (
       rc->connection,
       MHD_HTTP_BAD_REQUEST,
@@ -101,14 +101,12 @@ TEH_handler_csr_melt (struct TEH_RequestContext *rc,
                                           -1);
         if (GNUNET_OK != res)
         {
-          GNUNET_JSON_parse_free (spec);
           return (GNUNET_NO == res) ? MHD_YES : MHD_NO;
         }
         TALER_cs_refresh_nonce_derive (&rms,
                                        coin_off,
                                        &nonces[i]);
       }
-      GNUNET_JSON_parse_free (spec);
 
       for (unsigned int i = 0; i < csr_requests_num; i++)
       {
diff --git a/src/exchange/taler-exchange-httpd_management_extensions.c b/src/exchange/taler-exchange-httpd_management_extensions.c
index d5841a3c..3b24bace 100644
--- a/src/exchange/taler-exchange-httpd_management_extensions.c
+++ b/src/exchange/taler-exchange-httpd_management_extensions.c
@@ -145,7 +145,7 @@ set_extensions (void *cls,
 
 static enum GNUNET_GenericReturnValue
 verify_extensions_from_json (
-  json_t *extensions,
+  const json_t *extensions,
   struct SetExtensionsContext *sec)
 {
   const char*name;
@@ -160,7 +160,7 @@ verify_extensions_from_json (
   sec->extensions = GNUNET_new_array (sec->num_extensions,
                                       struct Extension);
 
-  json_object_foreach (extensions, name, manifest)
+  json_object_foreach ((json_t *) extensions, name, manifest)
   {
     int critical = 0;
     json_t *config;
@@ -200,11 +200,11 @@ TEH_handler_management_post_extensions (
   const json_t *root)
 {
   MHD_RESULT ret;
-  json_t *extensions;
+  const json_t *extensions;
   struct SetExtensionsContext sec = {0};
   struct GNUNET_JSON_Specification top_spec[] = {
-    GNUNET_JSON_spec_json ("extensions",
-                           &extensions),
+    GNUNET_JSON_spec_object_const ("extensions",
+                                   &extensions),
     GNUNET_JSON_spec_fixed_auto ("extensions_sig",
                                  &sec.extensions_sig),
     GNUNET_JSON_spec_end ()
@@ -223,31 +223,19 @@ TEH_handler_management_post_extensions (
       return MHD_YES; /* failure */
   }
 
-  /* Ensure we have an object */
-  if ((! json_is_object (extensions)) &&
-      (! json_is_null (extensions)))
-  {
-    GNUNET_JSON_parse_free (top_spec);
-    return TALER_MHD_reply_with_error (
-      connection,
-      MHD_HTTP_BAD_REQUEST,
-      TALER_EC_GENERIC_PARAMETER_MALFORMED,
-      "invalid object");
-  }
-
   /* Verify the signature */
   {
     struct TALER_ExtensionManifestsHashP h_manifests;
 
     if (GNUNET_OK !=
-        TALER_JSON_extensions_manifests_hash (extensions, &h_manifests) ||
+        TALER_JSON_extensions_manifests_hash (extensions,
+                                              &h_manifests) ||
         GNUNET_OK !=
         TALER_exchange_offline_extension_manifests_hash_verify (
           &h_manifests,
           &TEH_master_public_key,
           &sec.extensions_sig))
     {
-      GNUNET_JSON_parse_free (top_spec);
       return TALER_MHD_reply_with_error (
         connection,
         MHD_HTTP_BAD_REQUEST,
@@ -263,7 +251,6 @@ TEH_handler_management_post_extensions (
   if (GNUNET_OK !=
       verify_extensions_from_json (extensions, &sec))
   {
-    GNUNET_JSON_parse_free (top_spec);
     return TALER_MHD_reply_with_error (
       connection,
       MHD_HTTP_BAD_REQUEST,
@@ -306,7 +293,6 @@ CLEANUP:
     }
   }
   GNUNET_free (sec.extensions);
-  GNUNET_JSON_parse_free (top_spec);
   return ret;
 }
 
diff --git a/src/exchange/taler-exchange-httpd_management_post_keys.c b/src/exchange/taler-exchange-httpd_management_post_keys.c
index df351ad5..0ddc4691 100644
--- a/src/exchange/taler-exchange-httpd_management_post_keys.c
+++ b/src/exchange/taler-exchange-httpd_management_post_keys.c
@@ -340,13 +340,13 @@ TEH_handler_management_post_keys (
   const json_t *root)
 {
   struct AddKeysContext akc;
-  json_t *denom_sigs;
-  json_t *signkey_sigs;
+  const json_t *denom_sigs;
+  const json_t *signkey_sigs;
   struct GNUNET_JSON_Specification spec[] = {
-    GNUNET_JSON_spec_json ("denom_sigs",
-                           &denom_sigs),
-    GNUNET_JSON_spec_json ("signkey_sigs",
-                           &signkey_sigs),
+    GNUNET_JSON_spec_array_const ("denom_sigs",
+                                  &denom_sigs),
+    GNUNET_JSON_spec_array_const ("signkey_sigs",
+                                  &signkey_sigs),
     GNUNET_JSON_spec_end ()
   };
   bool ok;
@@ -363,24 +363,12 @@ TEH_handler_management_post_keys (
     if (GNUNET_NO == res)
       return MHD_YES; /* failure */
   }
-  if (! (json_is_array (denom_sigs) &&
-         json_is_array (signkey_sigs)) )
-  {
-    GNUNET_break_op (0);
-    GNUNET_JSON_parse_free (spec);
-    return TALER_MHD_reply_with_error (
-      connection,
-      MHD_HTTP_BAD_REQUEST,
-      TALER_EC_GENERIC_PARAMETER_MALFORMED,
-      "array expected for denom_sigs and signkey_sigs");
-  }
   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
               "Received /management/keys\n");
   akc.ksh = TEH_keys_get_state_for_management_only (); /* may start its own transaction, thus must be done here, before we run ours! */
   if (NULL == akc.ksh)
   {
     GNUNET_break_op (0);
-    GNUNET_JSON_parse_free (spec);
     return TALER_MHD_reply_with_error (
       connection,
       MHD_HTTP_INTERNAL_SERVER_ERROR,
@@ -423,7 +411,6 @@ TEH_handler_management_post_keys (
   if (! ok)
   {
     GNUNET_free (akc.d_sigs);
-    GNUNET_JSON_parse_free (spec);
     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                 "Failure to handle /management/keys\n");
     return ret;
@@ -466,7 +453,6 @@ TEH_handler_management_post_keys (
                 "Failure to handle /management/keys\n");
     GNUNET_free (akc.d_sigs);
     GNUNET_free (akc.s_sigs);
-    GNUNET_JSON_parse_free (spec);
     return ret;
   }
   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
@@ -484,7 +470,6 @@ TEH_handler_management_post_keys (
                                   &akc);
     GNUNET_free (akc.d_sigs);
     GNUNET_free (akc.s_sigs);
-    GNUNET_JSON_parse_free (spec);
     if (GNUNET_SYSERR == res)
       return ret;
   }
diff --git a/src/exchange/taler-exchange-httpd_management_wire_enable.c b/src/exchange/taler-exchange-httpd_management_wire_enable.c
index 6743b485..a67d1ad6 100644
--- a/src/exchange/taler-exchange-httpd_management_wire_enable.c
+++ b/src/exchange/taler-exchange-httpd_management_wire_enable.c
@@ -62,12 +62,12 @@ struct AddWireContext
   /**
    * Restrictions imposed when crediting this account.
    */
-  json_t *credit_restrictions;
+  const json_t *credit_restrictions;
 
   /**
    * Restrictions imposed when debiting this account.
    */
-  json_t *debit_restrictions;
+  const json_t *debit_restrictions;
 
   /**
    * Timestamp for checking against replay attacks.
@@ -176,10 +176,10 @@ TEH_handler_management_post_wire (
       GNUNET_JSON_spec_string ("conversion_url",
                                &awc.conversion_url),
       NULL),
-    GNUNET_JSON_spec_json ("credit_restrictions",
-                           &awc.credit_restrictions),
-    GNUNET_JSON_spec_json ("debit_restrictions",
-                           &awc.debit_restrictions),
+    GNUNET_JSON_spec_array_const ("credit_restrictions",
+                                  &awc.credit_restrictions),
+    GNUNET_JSON_spec_array_const ("debit_restrictions",
+                                  &awc.debit_restrictions),
     GNUNET_JSON_spec_timestamp ("validity_start",
                                 &awc.validity_start),
     GNUNET_JSON_spec_end ()
diff --git a/src/exchange/taler-exchange-httpd_purses_create.c b/src/exchange/taler-exchange-httpd_purses_create.c
index 130f9fae..2de9468f 100644
--- a/src/exchange/taler-exchange-httpd_purses_create.c
+++ b/src/exchange/taler-exchange-httpd_purses_create.c
@@ -430,7 +430,7 @@ TEH_handler_purses_create (
     .pd.purse_pub = *purse_pub,
     .exchange_timestamp = GNUNET_TIME_timestamp_get ()
   };
-  json_t *deposits;
+  const json_t *deposits;
   json_t *deposit;
   unsigned int idx;
   struct GNUNET_JSON_Specification spec[] = {
@@ -449,8 +449,8 @@ TEH_handler_purses_create (
                                  &pcc.purse_sig),
     GNUNET_JSON_spec_fixed_auto ("h_contract_terms",
                                  &pcc.pd.h_contract_terms),
-    GNUNET_JSON_spec_json ("deposits",
-                           &deposits),
+    GNUNET_JSON_spec_array_const ("deposits",
+                                  &deposits),
     GNUNET_JSON_spec_timestamp ("purse_expiration",
                                 &pcc.pd.purse_expiration),
     GNUNET_JSON_spec_end ()
@@ -482,7 +482,6 @@ TEH_handler_purses_create (
                                  pcc.exchange_timestamp))
   {
     GNUNET_break_op (0);
-    GNUNET_JSON_parse_free (spec);
     return TALER_MHD_reply_with_error (connection,
                                        MHD_HTTP_BAD_REQUEST,
                                        TALER_EC_EXCHANGE_PURSE_CREATE_EXPIRATION_BEFORE_NOW,
@@ -491,7 +490,6 @@ TEH_handler_purses_create (
   if (GNUNET_TIME_absolute_is_never (pcc.pd.purse_expiration.abs_time))
   {
     GNUNET_break_op (0);
-    GNUNET_JSON_parse_free (spec);
     return TALER_MHD_reply_with_error (connection,
                                        MHD_HTTP_BAD_REQUEST,
                                        TALER_EC_EXCHANGE_PURSE_CREATE_EXPIRATION_IS_NEVER,
@@ -502,7 +500,6 @@ TEH_handler_purses_create (
        (pcc.num_coins > TALER_MAX_FRESH_COINS) )
   {
     GNUNET_break_op (0);
-    GNUNET_JSON_parse_free (spec);
     return TALER_MHD_reply_with_error (connection,
                                        MHD_HTTP_BAD_REQUEST,
                                        TALER_EC_GENERIC_PARAMETER_MALFORMED,
@@ -515,7 +512,6 @@ TEH_handler_purses_create (
     if (NULL == keys)
     {
       GNUNET_break (0);
-      GNUNET_JSON_parse_free (spec);
       return TALER_MHD_reply_with_error (connection,
                                          MHD_HTTP_INTERNAL_SERVER_ERROR,
                                          TALER_EC_EXCHANGE_GENERIC_KEYS_MISSING,
@@ -547,7 +543,6 @@ TEH_handler_purses_create (
                       deposit);
     if (GNUNET_OK != res)
     {
-      GNUNET_JSON_parse_free (spec);
       for (unsigned int i = 0; i<idx; i++)
         TEH_common_purse_deposit_free_coin (&pcc.coins[i]);
       GNUNET_free (pcc.coins);
@@ -559,7 +554,6 @@ TEH_handler_purses_create (
                             &pcc.deposit_total))
   {
     GNUNET_break_op (0);
-    GNUNET_JSON_parse_free (spec);
     GNUNET_free (pcc.coins);
     return TALER_MHD_reply_with_error (connection,
                                        MHD_HTTP_BAD_REQUEST,
@@ -579,7 +573,6 @@ TEH_handler_purses_create (
         &pcc.purse_sig))
   {
     TALER_LOG_WARNING ("Invalid signature on /purses/$PID/create request\n");
-    GNUNET_JSON_parse_free (spec);
     for (unsigned int i = 0; i<pcc.num_coins; i++)
       TEH_common_purse_deposit_free_coin (&pcc.coins[i]);
     GNUNET_free (pcc.coins);
@@ -597,7 +590,6 @@ TEH_handler_purses_create (
                                               &pcc.econtract.econtract_sig)) )
   {
     TALER_LOG_WARNING ("Invalid signature on /purses/$PID/create request\n");
-    GNUNET_JSON_parse_free (spec);
     for (unsigned int i = 0; i<pcc.num_coins; i++)
       TEH_common_purse_deposit_free_coin (&pcc.coins[i]);
     GNUNET_free (pcc.coins);
@@ -612,7 +604,6 @@ TEH_handler_purses_create (
       TEH_plugin->preflight (TEH_plugin->cls))
   {
     GNUNET_break (0);
-    GNUNET_JSON_parse_free (spec);
     for (unsigned int i = 0; i<pcc.num_coins; i++)
       TEH_common_purse_deposit_free_coin (&pcc.coins[i]);
     GNUNET_free (pcc.coins);
@@ -634,7 +625,6 @@ TEH_handler_purses_create (
                                 &create_transaction,
                                 &pcc))
     {
-      GNUNET_JSON_parse_free (spec);
       for (unsigned int i = 0; i<pcc.num_coins; i++)
         TEH_common_purse_deposit_free_coin (&pcc.coins[i]);
       GNUNET_free (pcc.coins);
@@ -653,7 +643,6 @@ TEH_handler_purses_create (
     for (unsigned int i = 0; i<pcc.num_coins; i++)
       TEH_common_purse_deposit_free_coin (&pcc.coins[i]);
     GNUNET_free (pcc.coins);
-    GNUNET_JSON_parse_free (spec);
     return res;
   }
 }
diff --git a/src/exchange/taler-exchange-httpd_purses_deposit.c b/src/exchange/taler-exchange-httpd_purses_deposit.c
index 291807aa..973dfccf 100644
--- a/src/exchange/taler-exchange-httpd_purses_deposit.c
+++ b/src/exchange/taler-exchange-httpd_purses_deposit.c
@@ -329,12 +329,12 @@ TEH_handler_purses_deposit (
     .purse_pub = purse_pub,
     .exchange_timestamp = GNUNET_TIME_timestamp_get ()
   };
-  json_t *deposits;
+  const json_t *deposits;
   json_t *deposit;
   unsigned int idx;
   struct GNUNET_JSON_Specification spec[] = {
-    GNUNET_JSON_spec_json ("deposits",
-                           &deposits),
+    GNUNET_JSON_spec_array_const ("deposits",
+                                  &deposits),
     GNUNET_JSON_spec_end ()
   };
 
@@ -363,7 +363,6 @@ TEH_handler_purses_deposit (
        (pcc.num_coins > TALER_MAX_FRESH_COINS) )
   {
     GNUNET_break_op (0);
-    GNUNET_JSON_parse_free (spec);
     return TALER_MHD_reply_with_error (connection,
                                        MHD_HTTP_BAD_REQUEST,
                                        TALER_EC_GENERIC_PARAMETER_MALFORMED,
@@ -435,7 +434,6 @@ TEH_handler_purses_deposit (
                       deposit);
     if (GNUNET_OK != res)
     {
-      GNUNET_JSON_parse_free (spec);
       for (unsigned int i = 0; i<idx; i++)
         TEH_common_purse_deposit_free_coin (&pcc.coins[i]);
       GNUNET_free (pcc.coins);
@@ -447,7 +445,6 @@ TEH_handler_purses_deposit (
       TEH_plugin->preflight (TEH_plugin->cls))
   {
     GNUNET_break (0);
-    GNUNET_JSON_parse_free (spec);
     for (unsigned int i = 0; i<pcc.num_coins; i++)
       TEH_common_purse_deposit_free_coin (&pcc.coins[i]);
     GNUNET_free (pcc.coins);
@@ -469,7 +466,6 @@ TEH_handler_purses_deposit (
                                 &deposit_transaction,
                                 &pcc))
     {
-      GNUNET_JSON_parse_free (spec);
       for (unsigned int i = 0; i<pcc.num_coins; i++)
         TEH_common_purse_deposit_free_coin (&pcc.coins[i]);
       GNUNET_free (pcc.coins);
@@ -501,7 +497,6 @@ TEH_handler_purses_deposit (
     for (unsigned int i = 0; i<pcc.num_coins; i++)
       TEH_common_purse_deposit_free_coin (&pcc.coins[i]);
     GNUNET_free (pcc.coins);
-    GNUNET_JSON_parse_free (spec);
     return res;
   }
 }
diff --git a/src/exchange/taler-exchange-httpd_refreshes_reveal.c b/src/exchange/taler-exchange-httpd_refreshes_reveal.c
index 89bdf272..47926a74 100644
--- a/src/exchange/taler-exchange-httpd_refreshes_reveal.c
+++ b/src/exchange/taler-exchange-httpd_refreshes_reveal.c
@@ -983,26 +983,26 @@ TEH_handler_reveal (struct TEH_RequestContext *rc,
                     const json_t *root,
                     const char *const args[2])
 {
-  json_t *coin_evs;
-  json_t *transfer_privs;
-  json_t *link_sigs;
-  json_t *new_denoms_h;
-  json_t *old_age_commitment;
+  const json_t *coin_evs;
+  const json_t *transfer_privs;
+  const json_t *link_sigs;
+  const json_t *new_denoms_h;
+  const json_t *old_age_commitment;
   struct RevealContext rctx;
   struct GNUNET_JSON_Specification spec[] = {
     GNUNET_JSON_spec_fixed_auto ("transfer_pub",
                                  &rctx.gamma_tp),
-    GNUNET_JSON_spec_json ("transfer_privs",
-                           &transfer_privs),
-    GNUNET_JSON_spec_json ("link_sigs",
-                           &link_sigs),
-    GNUNET_JSON_spec_json ("coin_evs",
-                           &coin_evs),
-    GNUNET_JSON_spec_json ("new_denoms_h",
-                           &new_denoms_h),
+    GNUNET_JSON_spec_array_const ("transfer_privs",
+                                  &transfer_privs),
+    GNUNET_JSON_spec_array_const ("link_sigs",
+                                  &link_sigs),
+    GNUNET_JSON_spec_array_const ("coin_evs",
+                                  &coin_evs),
+    GNUNET_JSON_spec_array_const ("new_denoms_h",
+                                  &new_denoms_h),
     GNUNET_JSON_spec_mark_optional (
-      GNUNET_JSON_spec_json ("old_age_commitment",
-                             &old_age_commitment),
+      GNUNET_JSON_spec_array_const ("old_age_commitment",
+                                    &old_age_commitment),
       NULL),
     GNUNET_JSON_spec_mark_optional (
       GNUNET_JSON_spec_fixed_auto ("rms",
@@ -1053,7 +1053,6 @@ TEH_handler_reveal (struct TEH_RequestContext *rc,
   /* Note we do +1 as 1 row (cut-and-choose!) is missing! */
   if (TALER_CNC_KAPPA != json_array_size (transfer_privs) + 1)
   {
-    GNUNET_JSON_parse_free (spec);
     GNUNET_break_op (0);
     return TALER_MHD_reply_with_error (rc->connection,
                                        MHD_HTTP_BAD_REQUEST,
@@ -1061,19 +1060,13 @@ TEH_handler_reveal (struct TEH_RequestContext *rc,
                                        NULL);
   }
 
-  {
-    MHD_RESULT res;
-
-    res = handle_refreshes_reveal_json (rc->connection,
-                                        &rctx,
-                                        transfer_privs,
-                                        link_sigs,
-                                        new_denoms_h,
-                                        old_age_commitment,
-                                        coin_evs);
-    GNUNET_JSON_parse_free (spec);
-    return res;
-  }
+  return handle_refreshes_reveal_json (rc->connection,
+                                       &rctx,
+                                       transfer_privs,
+                                       link_sigs,
+                                       new_denoms_h,
+                                       old_age_commitment,
+                                       coin_evs);
 }
 
 
diff --git a/src/exchange/taler-exchange-httpd_reserves_attest.c b/src/exchange/taler-exchange-httpd_reserves_attest.c
index d0f3614e..7bbebaad 100644
--- a/src/exchange/taler-exchange-httpd_reserves_attest.c
+++ b/src/exchange/taler-exchange-httpd_reserves_attest.c
@@ -68,7 +68,7 @@ struct ReserveAttestContext
   /**
    * List of requested details.
    */
-  json_t *details;
+  const json_t *details;
 
   /**
    * Client signature approving the request.
@@ -287,8 +287,8 @@ TEH_handler_reserves_attest (struct TEH_RequestContext *rc,
   struct GNUNET_JSON_Specification spec[] = {
     GNUNET_JSON_spec_timestamp ("request_timestamp",
                                 &rsc.timestamp),
-    GNUNET_JSON_spec_json ("details",
-                           &rsc.details),
+    GNUNET_JSON_spec_array_const ("details",
+                                  &rsc.details),
     GNUNET_JSON_spec_fixed_auto ("reserve_sig",
                                  &rsc.reserve_sig),
     GNUNET_JSON_spec_end ()
diff --git a/src/exchange/taler-exchange-httpd_reserves_open.c b/src/exchange/taler-exchange-httpd_reserves_open.c
index 6909c862..50487990 100644
--- a/src/exchange/taler-exchange-httpd_reserves_open.c
+++ b/src/exchange/taler-exchange-httpd_reserves_open.c
@@ -303,7 +303,7 @@ TEH_handler_reserves_open (struct TEH_RequestContext *rc,
                            const json_t *root)
 {
   struct ReserveOpenContext rsc;
-  json_t *payments;
+  const json_t *payments;
   struct GNUNET_JSON_Specification spec[] = {
     GNUNET_JSON_spec_timestamp ("request_timestamp",
                                 &rsc.timestamp),
@@ -313,8 +313,8 @@ TEH_handler_reserves_open (struct TEH_RequestContext *rc,
                                  &rsc.reserve_sig),
     GNUNET_JSON_spec_uint32 ("purse_limit",
                              &rsc.purse_limit),
-    GNUNET_JSON_spec_json ("payments",
-                           &payments),
+    GNUNET_JSON_spec_array_const ("payments",
+                                  &payments),
     TALER_JSON_spec_amount ("reserve_payment",
                             TEH_currency,
                             &rsc.reserve_payment),
@@ -403,7 +403,6 @@ TEH_handler_reserves_open (struct TEH_RequestContext *rc,
     if (NULL == keys)
     {
       GNUNET_break (0);
-      GNUNET_JSON_parse_free (spec);
       cleanup_rsc (&rsc);
       return TALER_MHD_reply_with_error (rc->connection,
                                          MHD_HTTP_INTERNAL_SERVER_ERROR,