rpc: add a sanity limit to a few RPC in restricted mode

src/rpc/core_rpc_server.cpp

@@ -68,6 +68,11 @@ using namespace epee;
 #define DEFAULT_PAYMENT_DIFFICULTY 1000
 #define DEFAULT_PAYMENT_CREDITS_PER_HASH 100
 
+#define RESTRICTED_BLOCK_HEADER_RANGE 1000
+#define RESTRICTED_TRANSACTIONS_COUNT 100
+#define RESTRICTED_SPENT_KEY_IMAGES_COUNT 5000
+#define RESTRICTED_BLOCK_COUNT 1000
+
 #define RPC_TRACKER(rpc) \
   PERF_TIMER(rpc); \
   RPCTracker tracker(#rpc, PERF_TIMER_NAME(rpc))
@@ -639,6 +644,13 @@ namespace cryptonote
     if (use_bootstrap_daemon_if_necessary<COMMAND_RPC_GET_BLOCKS_BY_HEIGHT>(invoke_http_mode::BIN, "/getblocks_by_height.bin", req, res, r))
       return r;
 
+    const bool restricted = m_restricted && ctx;
+    if (restricted && req.heights.size() > RESTRICTED_BLOCK_COUNT)
+    {
+      res.status = "Too many blocks requested in restricted mode";
+      return true;
+    }
+
     res.status = "Failed";
     res.blocks.clear();
     res.blocks.reserve(req.heights.size());
@@ -793,11 +805,17 @@ namespace cryptonote
     if (use_bootstrap_daemon_if_necessary<COMMAND_RPC_GET_TRANSACTIONS>(invoke_http_mode::JON, "/gettransactions", req, res, ok))
       return ok;
 
-    CHECK_PAYMENT_MIN1(req, res, req.txs_hashes.size() * COST_PER_TX, false);
-
     const bool restricted = m_restricted && ctx;
     const bool request_has_rpc_origin = ctx != NULL;
 
+    if (restricted && req.txs_hashes.size() > RESTRICTED_TRANSACTIONS_COUNT)
+    {
+      res.status = "Too many transactions requested in restricted mode";
+      return true;
+    }
+
+    CHECK_PAYMENT_MIN1(req, res, req.txs_hashes.size() * COST_PER_TX, false);
+
     std::vector<crypto::hash> vh;
     for(const auto& tx_hex_str: req.txs_hashes)
     {
@@ -1027,11 +1045,17 @@ namespace cryptonote
     if (use_bootstrap_daemon_if_necessary<COMMAND_RPC_IS_KEY_IMAGE_SPENT>(invoke_http_mode::JON, "/is_key_image_spent", req, res, ok))
       return ok;
 
-    CHECK_PAYMENT_MIN1(req, res, req.key_images.size() * COST_PER_KEY_IMAGE, false);
-
     const bool restricted = m_restricted && ctx;
     const bool request_has_rpc_origin = ctx != NULL;
 
+    if (restricted && req.key_images.size() > RESTRICTED_SPENT_KEY_IMAGES_COUNT)
+    {
+      res.status = "Too many key images queried in restricted mode";
+      return true;
+    }
+
+    CHECK_PAYMENT_MIN1(req, res, req.key_images.size() * COST_PER_KEY_IMAGE, false);
+
     std::vector<crypto::key_image> key_images;
     for(const auto& ki_hex_str: req.key_images)
     {
@@ -2034,6 +2058,14 @@ namespace cryptonote
 
     CHECK_PAYMENT_MIN1(req, res, COST_PER_BLOCK_HEADER, false);
 
+    const bool restricted = m_restricted && ctx;
+    if (restricted && req.hashes.size() > RESTRICTED_BLOCK_COUNT)
+    {
+      error_resp.code = CORE_RPC_ERROR_CODE_RESTRICTED;
+      error_resp.message = "Too many block headers requested in restricted mode";
+      return false;
+    }
+
     auto get = [this](const std::string &hash, bool fill_pow_hash, block_header_response &block_header, bool restricted, epee::json_rpc::error& error_resp) -> bool {
       crypto::hash block_hash;
       bool hash_parsed = parse_hash256(hash, block_hash);
@@ -2069,7 +2101,6 @@ namespace cryptonote
       return true;
     };
 
-    const bool restricted = m_restricted && ctx;
     if (!req.hash.empty())
     {
       if (!get(req.hash, req.fill_pow_hash, res.block_header, restricted, error_resp))
@@ -2101,6 +2132,14 @@ namespace cryptonote
       error_resp.message = "Invalid start/end heights.";
       return false;
     }
+    const bool restricted = m_restricted && ctx;
+    if (restricted && req.end_height - req.start_height > RESTRICTED_BLOCK_HEADER_RANGE)
+    {
+      error_resp.code = CORE_RPC_ERROR_CODE_RESTRICTED;
+      error_resp.message = "Too many block headers requested.";
+      return false;
+    }
+
     CHECK_PAYMENT_MIN1(req, res, (req.end_height - req.start_height + 1) * COST_PER_BLOCK_HEADER, false);
     for (uint64_t h = req.start_height; h <= req.end_height; ++h)
     {
@@ -2127,7 +2166,6 @@ namespace cryptonote
         return false;
       }
       res.headers.push_back(block_header_response());
-      const bool restricted = m_restricted && ctx;
       bool response_filled = fill_block_header_response(blk, false, block_height, block_hash, res.headers.back(), req.fill_pow_hash && !restricted);
       if (!response_filled)
       {

src/rpc/core_rpc_server_error_codes.h

@@ -48,6 +48,7 @@
 #define CORE_RPC_ERROR_CODE_PAYMENT_TOO_LOW       -16
 #define CORE_RPC_ERROR_CODE_DUPLICATE_PAYMENT     -17
 #define CORE_RPC_ERROR_CODE_STALE_PAYMENT         -18
+#define CORE_RPC_ERROR_CODE_RESTRICTED            -19
 
 static inline const char *get_rpc_server_error_message(int64_t code)
 {
@@ -70,6 +71,7 @@ static inline const char *get_rpc_server_error_message(int64_t code)
     case CORE_RPC_ERROR_CODE_PAYMENT_TOO_LOW: return "Payment too low";
     case CORE_RPC_ERROR_CODE_DUPLICATE_PAYMENT: return "Duplicate payment";
     case CORE_RPC_ERROR_CODE_STALE_PAYMENT: return "Stale payment";
+    case CORE_RPC_ERROR_CODE_RESTRICTED: return "Parameters beyond restricted allowance";
     default: MERROR("Unknown error: " << code); return "Unknown error";
   }
 }