low risk, potentially varint overflow bug patched thanks to BBR

src/common/varint.h

@@ -36,7 +36,7 @@
 #include <sstream>
 #include <string>
 /*! \file varint.h
- * \breif provides the implementation of varint's
+ * \brief provides the implementation of varint's
  * 
  * The representation of varints is rather odd. The first bit of each
  * octet is significant, it represents wheter there is another part
@@ -52,6 +52,29 @@
 
 namespace tools {
 
+  template<typename T>
+  size_t get_varint_packed_size(T v)
+  {
+    if(v <= 127)
+      return 1;
+    else if(v <= 16383)
+      return 2;
+    else if(v <= 2097151)
+      return 3;
+    else if(v <= 268435455)
+      return 4;
+    else if(v <= 34359738367)
+      return 5;
+    else if(v <= 4398046511103)
+      return 6;
+    else if(v <= 4398046511103)
+      return 6;
+    else if(v <= 562949953421311)
+      return 7;
+    else 
+      return 8;
+  }
+
   /*! \brief Error codes for varint
    */
   enum {

src/cryptonote_core/cryptonote_basic.h

@@ -226,7 +226,6 @@ namespace cryptonote
       ar.end_array();
     END_SERIALIZE()
 
-  private:
     static size_t get_signature_size(const txin_v& tx_in);
   };
 

src/cryptonote_core/cryptonote_core.cpp

@@ -191,7 +191,7 @@ namespace cryptonote
       return false;
     }
 
-    bool r = add_new_tx(tx, tx_hash, tx_prefixt_hash, tx_blob.size(), tvc, keeped_by_block);
+    bool r = add_new_tx(tx, tx_hash, tx_prefixt_hash, tvc, keeped_by_block);
     if(tvc.m_verifivation_failed)
     {LOG_PRINT_RED_L1("Transaction verification failed: " << tx_hash);}
     else if(tvc.m_verifivation_impossible)
@@ -284,7 +284,7 @@ namespace cryptonote
     crypto::hash tx_prefix_hash = get_transaction_prefix_hash(tx);
     blobdata bl;
     t_serializable_object_to_blob(tx, bl);
-    return add_new_tx(tx, tx_hash, tx_prefix_hash, bl.size(), tvc, keeped_by_block);
+    return add_new_tx(tx, tx_hash, tx_prefix_hash, tvc, keeped_by_block);
   }
   //-----------------------------------------------------------------------------------------------
   size_t core::get_blockchain_total_transactions()
@@ -297,7 +297,7 @@ namespace cryptonote
   //  return m_blockchain_storage.get_outs(amount, pkeys);
   //}
   //-----------------------------------------------------------------------------------------------
-  bool core::add_new_tx(const transaction& tx, const crypto::hash& tx_hash, const crypto::hash& tx_prefix_hash, size_t blob_size, tx_verification_context& tvc, bool keeped_by_block)
+  bool core::add_new_tx(const transaction& tx, const crypto::hash& tx_hash, const crypto::hash& tx_prefix_hash, tx_verification_context& tvc, bool keeped_by_block)
   {
     if(m_mempool.have_tx(tx_hash))
     {
@@ -311,7 +311,7 @@ namespace cryptonote
       return true;
     }
 
-    return m_mempool.add_tx(tx, tx_hash, blob_size, tvc, keeped_by_block);
+    return m_mempool.add_tx(tx, tx_hash, tvc, keeped_by_block);
   }
   //-----------------------------------------------------------------------------------------------
   bool core::get_block_template(block& b, const account_public_address& adr, difficulty_type& diffic, uint64_t& height, const blobdata& ex_nonce)

src/cryptonote_core/cryptonote_core.h

@@ -120,7 +120,7 @@ namespace cryptonote
      uint64_t get_target_blockchain_height() const;
 
    private:
-     bool add_new_tx(const transaction& tx, const crypto::hash& tx_hash, const crypto::hash& tx_prefix_hash, size_t blob_size, tx_verification_context& tvc, bool keeped_by_block);
+     bool add_new_tx(const transaction& tx, const crypto::hash& tx_hash, const crypto::hash& tx_prefix_hash, tx_verification_context& tvc, bool keeped_by_block);
      bool add_new_tx(const transaction& tx, tx_verification_context& tvc, bool keeped_by_block);
      bool add_new_block(const block& b, block_verification_context& bvc);
      bool load_state_data();

src/cryptonote_core/cryptonote_format_utils.cpp

@@ -742,6 +742,23 @@ namespace cryptonote
     return true;
   }
   //---------------------------------------------------------------
+  size_t get_object_blobsize(const transaction& t)
+  {
+    size_t prefix_blob = get_object_blobsize(static_cast<const transaction_prefix&>(t));
+
+    if(is_coinbase(t))    
+      return prefix_blob;    
+
+    for(const auto& in: t.vin)
+    {
+      size_t sig_count = transaction::get_signature_size(in);
+      prefix_blob += 64*sig_count;
+      prefix_blob += tools::get_varint_packed_size(sig_count);
+    }
+    prefix_blob += tools::get_varint_packed_size(t.vin.size());
+    return prefix_blob;
+  }
+  //---------------------------------------------------------------
   blobdata block_to_blob(const block& b)
   {
     return t_serializable_object_to_blob(b);

src/cryptonote_core/cryptonote_format_utils.h

@@ -157,6 +157,8 @@ namespace cryptonote
     return b.size();
   }
   //---------------------------------------------------------------
+  size_t get_object_blobsize(const transaction& t);
+  //---------------------------------------------------------------
   template<class t_object>
   bool get_object_hash(const t_object& o, crypto::hash& res, size_t& blob_size)
   {

src/cryptonote_core/tx_pool.cpp

@@ -59,9 +59,9 @@ namespace cryptonote
 
   }
   //---------------------------------------------------------------------------------
-  bool tx_memory_pool::add_tx(const transaction &tx, /*const crypto::hash& tx_prefix_hash,*/ const crypto::hash &id, size_t blob_size, tx_verification_context& tvc, bool kept_by_block)
+  bool tx_memory_pool::add_tx(const transaction &tx, const crypto::hash &id, tx_verification_context& tvc, bool kept_by_block)
   {
-
+    size_t blob_size = get_object_blobsize(tx);
 
     if(!check_inputs_types_supported(tx))
     {
@@ -179,9 +179,8 @@ namespace cryptonote
   bool tx_memory_pool::add_tx(const transaction &tx, tx_verification_context& tvc, bool keeped_by_block)
   {
     crypto::hash h = null_hash;
-    size_t blob_size = 0;
-    get_transaction_hash(tx, h, blob_size);
-    return add_tx(tx, h, blob_size, tvc, keeped_by_block);
+    get_transaction_hash(tx, h);
+    return add_tx(tx, h, tvc, keeped_by_block);
   }
   //---------------------------------------------------------------------------------
   bool tx_memory_pool::remove_transaction_keyimages(const transaction& tx)

src/cryptonote_core/tx_pool.h

@@ -56,7 +56,7 @@ namespace cryptonote
   {
   public:
     tx_memory_pool(blockchain_storage& bchs);
-    bool add_tx(const transaction &tx, const crypto::hash &id, size_t blob_size, tx_verification_context& tvc, bool keeped_by_block);
+    bool add_tx(const transaction &tx, const crypto::hash &id, tx_verification_context& tvc, bool keeped_by_block);
     bool add_tx(const transaction &tx, tx_verification_context& tvc, bool keeped_by_block);
     //gets tx and remove it from pool
     bool take_tx(const crypto::hash &id, transaction &tx, size_t& blob_size, uint64_t& fee);
@@ -81,7 +81,7 @@ namespace cryptonote
     /*bool flush_pool(const std::strig& folder);
     bool inflate_pool(const std::strig& folder);*/
 
-#define CURRENT_MEMPOOL_ARCHIVE_VER    8
+#define CURRENT_MEMPOOL_ARCHIVE_VER    9
 
     template<class archive_t>
     void serialize(archive_t & a, const unsigned int version)

tests/unit_tests/serialization.cpp

@@ -299,6 +299,37 @@ namespace
   }
 }
 
+bool test_get_varint_packed_size_for_num(uint64_t n)
+{
+std::stringstream ss;
+typedef std::ostreambuf_iterator<char> it;
+tools::write_varint(it(ss), n);
+uint64_t sz = ss.str().size();
+if(sz != tools::get_varint_packed_size(n))
+return false;
+else 
+return true;
+}
+TEST(Serialization, validate_get_varint_packed_size)
+{
+ASSERT_TRUE(test_get_varint_packed_size_for_num(127));
+ASSERT_TRUE(test_get_varint_packed_size_for_num(128));
+ASSERT_TRUE(test_get_varint_packed_size_for_num(16383));
+ASSERT_TRUE(test_get_varint_packed_size_for_num(16383+1));
+ASSERT_TRUE(test_get_varint_packed_size_for_num(2097151));
+ASSERT_TRUE(test_get_varint_packed_size_for_num(2097151+1));
+ASSERT_TRUE(test_get_varint_packed_size_for_num(268435455));
+ASSERT_TRUE(test_get_varint_packed_size_for_num(268435455+1));
+ASSERT_TRUE(test_get_varint_packed_size_for_num(34359738367));
+ASSERT_TRUE(test_get_varint_packed_size_for_num(34359738367+1));
+ASSERT_TRUE(test_get_varint_packed_size_for_num(4398046511103));
+ASSERT_TRUE(test_get_varint_packed_size_for_num(4398046511103+1));
+ASSERT_TRUE(test_get_varint_packed_size_for_num(4398046511103));
+ASSERT_TRUE(test_get_varint_packed_size_for_num(4398046511103+1));
+ASSERT_TRUE(test_get_varint_packed_size_for_num(562949953421311));
+ASSERT_TRUE(test_get_varint_packed_size_for_num(562949953421311+1));
+}
+
 TEST(Serialization, serializes_transacion_signatures_correctly)
 {
   using namespace cryptonote;