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-rw-r--r--src/cryptonote_core/cryptonote_core.cpp10
-rw-r--r--src/cryptonote_core/cryptonote_core.h8
-rw-r--r--src/cryptonote_protocol/cryptonote_protocol_defs.h2
-rw-r--r--src/cryptonote_protocol/cryptonote_protocol_handler.inl31
-rw-r--r--tests/core_proxy/core_proxy.h1
-rw-r--r--tests/unit_tests/ban.cpp1
6 files changed, 52 insertions, 1 deletions
diff --git a/src/cryptonote_core/cryptonote_core.cpp b/src/cryptonote_core/cryptonote_core.cpp
index d8c38bf9e..c55499365 100644
--- a/src/cryptonote_core/cryptonote_core.cpp
+++ b/src/cryptonote_core/cryptonote_core.cpp
@@ -163,6 +163,11 @@ namespace cryptonote
, "Relay blocks as normal blocks"
, false
};
+ static const command_line::arg_descriptor<bool> arg_pad_transactions = {
+ "pad-transactions"
+ , "Pad relayed transactions to help defend against traffic volume analysis"
+ , false
+ };
static const command_line::arg_descriptor<size_t> arg_max_txpool_weight = {
"max-txpool-weight"
, "Set maximum txpool weight in bytes."
@@ -188,7 +193,8 @@ namespace cryptonote
m_disable_dns_checkpoints(false),
m_update_download(0),
m_nettype(UNDEFINED),
- m_update_available(false)
+ m_update_available(false),
+ m_pad_transactions(false)
{
m_checkpoints_updating.clear();
set_cryptonote_protocol(pprotocol);
@@ -282,6 +288,7 @@ namespace cryptonote
command_line::add_arg(desc, arg_offline);
command_line::add_arg(desc, arg_disable_dns_checkpoints);
command_line::add_arg(desc, arg_max_txpool_weight);
+ command_line::add_arg(desc, arg_pad_transactions);
command_line::add_arg(desc, arg_block_notify);
miner::init_options(desc);
@@ -320,6 +327,7 @@ namespace cryptonote
set_enforce_dns_checkpoints(command_line::get_arg(vm, arg_dns_checkpoints));
test_drop_download_height(command_line::get_arg(vm, arg_test_drop_download_height));
m_fluffy_blocks_enabled = !get_arg(vm, arg_no_fluffy_blocks);
+ m_pad_transactions = get_arg(vm, arg_pad_transactions);
m_offline = get_arg(vm, arg_offline);
m_disable_dns_checkpoints = get_arg(vm, arg_disable_dns_checkpoints);
if (!command_line::is_arg_defaulted(vm, arg_fluffy_blocks))
diff --git a/src/cryptonote_core/cryptonote_core.h b/src/cryptonote_core/cryptonote_core.h
index 80c452f53..cef42d207 100644
--- a/src/cryptonote_core/cryptonote_core.h
+++ b/src/cryptonote_core/cryptonote_core.h
@@ -757,6 +757,13 @@ namespace cryptonote
bool fluffy_blocks_enabled() const { return m_fluffy_blocks_enabled; }
/**
+ * @brief get whether transaction relay should be padded
+ *
+ * @return whether transaction relay should be padded
+ */
+ bool pad_transactions() const { return m_pad_transactions; }
+
+ /**
* @brief check a set of hashes against the precompiled hash set
*
* @return number of usable blocks
@@ -1014,6 +1021,7 @@ namespace cryptonote
bool m_fluffy_blocks_enabled;
bool m_offline;
+ bool m_pad_transactions;
};
}
diff --git a/src/cryptonote_protocol/cryptonote_protocol_defs.h b/src/cryptonote_protocol/cryptonote_protocol_defs.h
index db159f0f4..d5bb50930 100644
--- a/src/cryptonote_protocol/cryptonote_protocol_defs.h
+++ b/src/cryptonote_protocol/cryptonote_protocol_defs.h
@@ -146,9 +146,11 @@ namespace cryptonote
struct request
{
std::vector<blobdata> txs;
+ std::string _; // padding
BEGIN_KV_SERIALIZE_MAP()
KV_SERIALIZE(txs)
+ KV_SERIALIZE(_)
END_KV_SERIALIZE_MAP()
};
};
diff --git a/src/cryptonote_protocol/cryptonote_protocol_handler.inl b/src/cryptonote_protocol/cryptonote_protocol_handler.inl
index c2c660e8c..6efdcc25e 100644
--- a/src/cryptonote_protocol/cryptonote_protocol_handler.inl
+++ b/src/cryptonote_protocol/cryptonote_protocol_handler.inl
@@ -1724,8 +1724,39 @@ skip:
bool t_cryptonote_protocol_handler<t_core>::relay_transactions(NOTIFY_NEW_TRANSACTIONS::request& arg, cryptonote_connection_context& exclude_context)
{
// no check for success, so tell core they're relayed unconditionally
+ const bool pad_transactions = m_core.pad_transactions();
+ size_t bytes = pad_transactions ? 9 /* header */ + 4 /* 1 + 'txs' */ + tools::get_varint_data(arg.txs.size()).size() : 0;
for(auto tx_blob_it = arg.txs.begin(); tx_blob_it!=arg.txs.end(); ++tx_blob_it)
+ {
m_core.on_transaction_relayed(*tx_blob_it);
+ if (pad_transactions)
+ bytes += tools::get_varint_data(tx_blob_it->size()).size() + tx_blob_it->size();
+ }
+
+ if (pad_transactions)
+ {
+ // stuff some dummy bytes in to stay safe from traffic volume analysis
+ static constexpr size_t granularity = 1024;
+ size_t padding = granularity - bytes % granularity;
+ const size_t overhead = 2 /* 1 + '_' */ + tools::get_varint_data(padding).size();
+ if (overhead > padding)
+ padding = 0;
+ else
+ padding -= overhead;
+ arg._ = std::string(padding, ' ');
+
+ std::string arg_buff;
+ epee::serialization::store_t_to_binary(arg, arg_buff);
+
+ // we probably lowballed the payload size a bit, so added a but too much. Fix this now.
+ size_t remove = arg_buff.size() % granularity;
+ if (remove > arg._.size())
+ arg._.clear();
+ else
+ arg._.resize(arg._.size() - remove);
+ // if the size of _ moved enough, we might lose byte in size encoding, we don't care
+ }
+
return relay_post_notify<NOTIFY_NEW_TRANSACTIONS>(arg, exclude_context);
}
//------------------------------------------------------------------------------------------------------------------------
diff --git a/tests/core_proxy/core_proxy.h b/tests/core_proxy/core_proxy.h
index 7d36a0f68..023c220ae 100644
--- a/tests/core_proxy/core_proxy.h
+++ b/tests/core_proxy/core_proxy.h
@@ -104,5 +104,6 @@ namespace tests
cryptonote::difficulty_type get_block_cumulative_difficulty(uint64_t height) const { return 0; }
bool fluffy_blocks_enabled() const { return false; }
uint64_t prevalidate_block_hashes(uint64_t height, const std::vector<crypto::hash> &hashes) { return 0; }
+ bool pad_transactions() const { return false; }
};
}
diff --git a/tests/unit_tests/ban.cpp b/tests/unit_tests/ban.cpp
index e3dbdaef1..12625a949 100644
--- a/tests/unit_tests/ban.cpp
+++ b/tests/unit_tests/ban.cpp
@@ -83,6 +83,7 @@ public:
cryptonote::difficulty_type get_block_cumulative_difficulty(uint64_t height) const { return 0; }
bool fluffy_blocks_enabled() const { return false; }
uint64_t prevalidate_block_hashes(uint64_t height, const std::vector<crypto::hash> &hashes) { return 0; }
+ bool pad_transactions() { return false; }
void stop() {}
};
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-16 02:17:03 +0000