initial import of Monero base code

src/cryptonote_core/tx_sanity_check.cpp

@@ -0,0 +1,104 @@
+// Copyright (c) 2019-2023, The Monero Project
+// 
+// All rights reserved.
+// 
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+// 
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+// 
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+// 
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+// 
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include <stdint.h>
+#include <vector>
+#include "cryptonote_basic/cryptonote_basic.h"
+#include "cryptonote_basic/cryptonote_format_utils.h"
+#include "blockchain.h"
+#include "tx_sanity_check.h"
+
+#undef MONERO_DEFAULT_LOG_CATEGORY
+#define MONERO_DEFAULT_LOG_CATEGORY "verify"
+
+namespace cryptonote
+{
+
+bool tx_sanity_check(const cryptonote::blobdata &tx_blob, uint64_t rct_outs_available)
+{
+  cryptonote::transaction tx;
+
+  if (!cryptonote::parse_and_validate_tx_from_blob(tx_blob, tx))
+  {
+    MERROR("Failed to parse transaction");
+    return false;
+  }
+
+  if (cryptonote::is_coinbase(tx))
+  {
+    MERROR("Transaction is coinbase");
+    return false;
+  }
+  std::set<uint64_t> rct_indices;
+  size_t n_indices = 0;
+
+  for (const auto &txin : tx.vin)
+  {
+    if (txin.type() != typeid(cryptonote::txin_to_key))
+      continue;
+    const cryptonote::txin_to_key &in_to_key = boost::get<cryptonote::txin_to_key>(txin);
+    if (in_to_key.amount != 0)
+      continue;
+    const std::vector<uint64_t> absolute = cryptonote::relative_output_offsets_to_absolute(in_to_key.key_offsets);
+    for (uint64_t offset: absolute)
+      rct_indices.insert(offset);
+    n_indices += in_to_key.key_offsets.size();
+  }
+
+  return tx_sanity_check(rct_indices, n_indices, rct_outs_available);
+}
+
+bool tx_sanity_check(const std::set<uint64_t> &rct_indices, size_t n_indices, uint64_t rct_outs_available)
+{
+  if (n_indices <= 10)
+  {
+    MDEBUG("n_indices is only " << n_indices << ", not checking");
+    return true;
+  }
+
+  if (rct_outs_available < 10000)
+    return true;
+
+  if (rct_indices.size() < n_indices * 8 / 10)
+  {
+    MERROR("amount of unique indices is too low (amount of rct indices is " << rct_indices.size() << ", out of total " << n_indices << "indices.");
+    return false;
+  }
+
+  std::vector<uint64_t> offsets(rct_indices.begin(), rct_indices.end());
+  uint64_t median = epee::misc_utils::median(offsets);
+  if (median < rct_outs_available * 6 / 10)
+  {
+    MERROR("median offset index is too low (median is " << median << " out of total " << rct_outs_available << "offsets). Transactions should contain a higher fraction of recent outputs.");
+    return false;
+  }
+
+  return true;
+}
+
+}