fix error handling for very large uploads, fix re-generation of /keys response after Expires expires

src/exchange/taler-exchange-httpd.c

@@ -1003,6 +1003,36 @@ handle_mhd_request (void *cls,
                   "illegal incoming correlation ID\n");
       correlation_id = NULL;
     }
+
+    /* Check if upload is in bounds */
+    if (0 == strcasecmp (method,
+                         MHD_HTTP_METHOD_POST))
+    {
+      const char *cl;
+
+      /* Maybe check for maximum upload size
+         and refuse requests if they are just too big. */
+      cl = MHD_lookup_connection_value (connection,
+                                        MHD_HEADER_KIND,
+                                        MHD_HTTP_HEADER_CONTENT_LENGTH);
+      if (NULL != cl)
+      {
+        unsigned long long cv;
+        char dummy;
+
+        if (1 != sscanf (cl,
+                         "%llu%c",
+                         &cv,
+                         &dummy))
+        {
+          /* Not valid HTTP request, just close connection. */
+          GNUNET_break_op (0);
+          return MHD_NO;
+        }
+        if (cv > TALER_MHD_REQUEST_BUFFER_MAX)
+          return TALER_MHD_reply_request_too_large (connection);
+      }
+    }
   }
 
   GNUNET_async_scope_enter (&rc->async_scope_id,

src/exchange/taler-exchange-httpd_keys.c

@@ -1557,7 +1557,7 @@ get_date_string (struct GNUNET_TIME_Absolute at,
  * @return #GNUNET_OK on success
  */
 static enum GNUNET_GenericReturnValue
-setup_general_response_headers (const struct TEH_KeyStateHandle *ksh,
+setup_general_response_headers (struct TEH_KeyStateHandle *ksh,
                                 struct MHD_Response *response)
 {
   char dat[128];
@@ -1590,6 +1590,9 @@ setup_general_response_headers (const struct TEH_KeyStateHandle *ksh,
                   MHD_add_response_header (response,
                                            MHD_HTTP_HEADER_EXPIRES,
                                            dat));
+    ksh->signature_expires
+      = GNUNET_TIME_absolute_min (m,
+                                  ksh->signature_expires);
   }
   return GNUNET_OK;
 }

src/exchange/taler-exchange-httpd_management_post_keys.c

@@ -367,6 +367,8 @@ TEH_handler_management_post_keys (
       TALER_EC_GENERIC_PARAMETER_MALFORMED,
       "array expected for denom_sigs and signkey_sigs");
   }
+  GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+              "Received /management/keys\n");
   akc.nd_sigs = json_array_size (denom_sigs);
   akc.d_sigs = GNUNET_new_array (akc.nd_sigs,
                                  struct DenomSig);
@@ -404,6 +406,8 @@ TEH_handler_management_post_keys (
   {
     GNUNET_free (akc.d_sigs);
     GNUNET_JSON_parse_free (spec);
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                "Failure to handle /management/keys\n");
     return ret;
   }
   akc.ns_sigs = json_array_size (signkey_sigs);
@@ -440,6 +444,8 @@ TEH_handler_management_post_keys (
   }
   if (! ok)
   {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                "Failure to handle /management/keys\n");
     GNUNET_free (akc.d_sigs);
     GNUNET_free (akc.s_sigs);
     GNUNET_JSON_parse_free (spec);

src/include/taler_mhd_lib.h

@@ -30,6 +30,12 @@
 #include <gnunet/gnunet_mhd_compat.h>
 
 
+/**
+ * Maximum POST request size.
+ */
+#define TALER_MHD_REQUEST_BUFFER_MAX (1024 * 1024 * 16)
+
+
 /**
  * Global options for response generation.
  */

src/lib/exchange_api_management_post_keys.c

@@ -99,6 +99,10 @@ handle_post_keys_finished (void *cls,
     hr.ec = TALER_JSON_get_error_code (json);
     hr.hint = TALER_JSON_get_error_hint (json);
     break;
+  case MHD_HTTP_REQUEST_ENTITY_TOO_LARGE:
+    hr.ec = TALER_JSON_get_error_code (json);
+    hr.hint = TALER_JSON_get_error_hint (json);
+    break;
   default:
     /* unexpected response code */
     GNUNET_break_op (0);

src/mhd/mhd_parsing.c

@@ -27,12 +27,6 @@
 #include "taler_mhd_lib.h"
 
 
-/**
- * Maximum POST request size.
- */
-#define REQUEST_BUFFER_MAX (1024 * 1024)
-
-
 /**
  * Process a POST request containing a JSON object.  This function
  * realizes an MHD POST processor that will (incrementally) process
@@ -65,7 +59,7 @@ TALER_MHD_parse_post_json (struct MHD_Connection *connection,
 {
   enum GNUNET_JSON_PostResult pr;
 
-  pr = GNUNET_JSON_post_parser (REQUEST_BUFFER_MAX,
+  pr = GNUNET_JSON_post_parser (TALER_MHD_REQUEST_BUFFER_MAX,
                                 connection,
                                 con_cls,
                                 upload_data,
@@ -87,9 +81,9 @@ TALER_MHD_parse_post_json (struct MHD_Connection *connection,
     return GNUNET_YES;
   case GNUNET_JSON_PR_REQUEST_TOO_LARGE:
     GNUNET_break (NULL == *json);
-    return (MHD_NO ==
-            TALER_MHD_reply_request_too_large
-              (connection)) ? GNUNET_SYSERR : GNUNET_NO;
+    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+                "Closing connection, upload too large\n");
+    return MHD_NO;
   case GNUNET_JSON_PR_JSON_INVALID:
     GNUNET_break (NULL == *json);
     return (MHD_YES ==

src/mhd/mhd_responses.c

@@ -419,24 +419,10 @@ TALER_MHD_reply_with_ec (struct MHD_Connection *connection,
 MHD_RESULT
 TALER_MHD_reply_request_too_large (struct MHD_Connection *connection)
 {
-  struct MHD_Response *response;
-
-  response = MHD_create_response_from_buffer (0,
-                                              NULL,
-                                              MHD_RESPMEM_PERSISTENT);
-  if (NULL == response)
-    return MHD_NO;
-  TALER_MHD_add_global_headers (response);
-
-  {
-    MHD_RESULT ret;
-
-    ret = MHD_queue_response (connection,
+  return TALER_MHD_reply_with_error (connection,
                                      MHD_HTTP_REQUEST_ENTITY_TOO_LARGE,
-                              response);
-    MHD_destroy_response (response);
-    return ret;
-  }
+                                     TALER_EC_GENERIC_UPLOAD_EXCEEDS_LIMIT,
+                                     NULL);
 }