rct: do not serialize public keys in outPk

They can be reconstructed from vout

3 files changed, 53 insertions, 13 deletions

diff --git a/src/cryptonote_core/blockchain.cpp b/src/cryptonote_core/blockchain.cpp
index 456a78eaf..9972b25e5 100644
--- a/src/cryptonote_core/blockchain.cpp
+++ b/src/cryptonote_core/blockchain.cpp
@@ -2468,11 +2468,12 @@ bool Blockchain::check_tx_inputs(const transaction& tx, tx_verification_context
     {
       rct::ctkeyM reconstructed_mixRing;
       std::vector<rct::keyV> reconstructed_II;
+      rct::ctkeyV reconstructed_outPk;
 
       // if the tx already has a non empty mixRing, use them,
       // else reconstruct them
       const rct::ctkeyM &mixRing = tx.rct_signatures.mixRing.empty() ? reconstructed_mixRing : tx.rct_signatures.mixRing;
-      // always do II, because it's split in the simple version
+      // always do II, because it's split in the simple version, and always do outPk
 
       // all MGs should have the same II size (1)
       for (size_t n = 0; n < tx.rct_signatures.MGs.size(); ++n)
@@ -2491,6 +2492,18 @@ bool Blockchain::check_tx_inputs(const transaction& tx, tx_verification_context
         reconstructed_II[n].push_back(tx.rct_signatures.MGs[n].II[0]);
       }
 
+      if (tx.rct_signatures.outPk.size() != tx.vout.size())
+      {
+        LOG_PRINT_L1("Failed to check ringct signatures: outPk and vout have different sizes");
+        return false;
+      }
+      reconstructed_outPk.resize(tx.vout.size());
+      for (size_t n = 0; n < tx.vout.size(); ++n)
+      {
+        reconstructed_outPk[n].dest = rct::pk2rct(boost::get<txout_to_key>(tx.vout[n].target).key);
+        reconstructed_outPk[n].mask = tx.rct_signatures.outPk[n].mask;
+      }
+
       if (tx.rct_signatures.mixRing.empty())
       {
         reconstructed_mixRing.resize(pubkeys.size());
@@ -2551,7 +2564,7 @@ bool Blockchain::check_tx_inputs(const transaction& tx, tx_verification_context
         }
       }
 
-      if (!rct::verRctSimple(tx.rct_signatures, mixRing, &reconstructed_II, rct::hash2rct(tx_prefix_hash)))
+      if (!rct::verRctSimple(tx.rct_signatures, mixRing, &reconstructed_II, reconstructed_outPk, rct::hash2rct(tx_prefix_hash)))
       {
         LOG_PRINT_L1("Failed to check ringct signatures!");
         return false;
@@ -2561,11 +2574,13 @@ bool Blockchain::check_tx_inputs(const transaction& tx, tx_verification_context
     {
       rct::ctkeyM reconstructed_mixRing;
       rct::keyV reconstructed_II;
+      rct::ctkeyV reconstructed_outPk;
 
       // if the tx already has a non empty mixRing and/or II, use them,
-      // else reconstruct them
+      // else reconstruct them. Always do outPk.
       const rct::ctkeyM &mixRing = tx.rct_signatures.mixRing.empty() ? reconstructed_mixRing : tx.rct_signatures.mixRing;
       const rct::keyV &II = tx.rct_signatures.MG.II.size() == 1 ? reconstructed_II : tx.rct_signatures.MG.II;
+      const rct::ctkeyV outPk = reconstructed_outPk;
 
       // RCT needs the same mixin for all inputs
       for (size_t n = 1; n < pubkeys.size(); ++n)
@@ -2599,6 +2614,18 @@ bool Blockchain::check_tx_inputs(const transaction& tx, tx_verification_context
         reconstructed_II.push_back(tx.rct_signatures.MG.II.back());
       }
 
+      if (tx.rct_signatures.outPk.size() != tx.vout.size())
+      {
+        LOG_PRINT_L1("Failed to check ringct signatures: outPk and vout have different sizes");
+        return false;
+      }
+      reconstructed_outPk.resize(tx.vout.size());
+      for (size_t n = 0; n < tx.vout.size(); ++n)
+      {
+        reconstructed_outPk[n].dest = rct::pk2rct(boost::get<txout_to_key>(tx.vout[n].target).key);
+        reconstructed_outPk[n].mask = tx.rct_signatures.outPk[n].mask;
+      }
+
       // check all this, either recontructed (so should really pass), or not
       {
         bool size_matches = true;
@@ -2644,7 +2671,7 @@ bool Blockchain::check_tx_inputs(const transaction& tx, tx_verification_context
         }
       }
 
-      if (!rct::verRct(tx.rct_signatures, mixRing, II, rct::hash2rct(tx_prefix_hash)))
+      if (!rct::verRct(tx.rct_signatures, mixRing, II, outPk, rct::hash2rct(tx_prefix_hash)))
       {
         LOG_PRINT_L1("Failed to check ringct signatures!");
         return false;
diff --git a/src/cryptonote_core/cryptonote_boost_serialization.h b/src/cryptonote_core/cryptonote_boost_serialization.h
index 35fabe7fb..81f5f081a 100644
--- a/src/cryptonote_core/cryptonote_boost_serialization.h
+++ b/src/cryptonote_core/cryptonote_boost_serialization.h
@@ -43,6 +43,7 @@
 #include "common/unordered_containers_boost_serialization.h"
 #include "crypto/crypto.h"
 #include "ringct/rctTypes.h"
+#include "ringct/rctOps.h"
 
 //namespace cryptonote {
 namespace boost
@@ -221,6 +222,26 @@ namespace boost
     a & x.senderPk;
   }
 
+  inline void serializeOutPk(boost::archive::binary_iarchive &a, rct::ctkeyV &outPk_, const boost::serialization::version_type ver)
+  {
+    rct::keyV outPk;
+    a & outPk;
+    outPk_.resize(outPk.size());
+    for (size_t n = 0; n < outPk_.size(); ++n)
+    {
+      outPk_[n].dest = rct::identity();
+      outPk_[n].mask = outPk[n];
+    }
+  }
+
+  inline void serializeOutPk(boost::archive::binary_oarchive &a, rct::ctkeyV &outPk_, const boost::serialization::version_type ver)
+  {
+    rct::keyV outPk(outPk_.size());
+    for (size_t n = 0; n < outPk_.size(); ++n)
+      outPk[n] = outPk_[n].mask;
+    a & outPk;
+  }
+
   template <class Archive>
   inline void serialize(Archive &a, rct::rctSig &x, const boost::serialization::version_type ver)
   {
@@ -235,7 +256,7 @@ namespace boost
     if (x.simple)
       a & x.pseudoOuts;
     a & x.ecdhInfo;
-    a & x.outPk;
+    serializeOutPk(a, x.outPk, ver);
     a & x.txnFee;
   }
 }
diff --git a/src/cryptonote_core/cryptonote_core.cpp b/src/cryptonote_core/cryptonote_core.cpp
index 880162ed2..511f50616 100644
--- a/src/cryptonote_core/cryptonote_core.cpp
+++ b/src/cryptonote_core/cryptonote_core.cpp
@@ -569,14 +569,6 @@ namespace cryptonote
         LOG_PRINT_RED_L1("tx with mismatched vout/outPk count, rejected for tx id= " << get_transaction_hash(tx));
         return false;
       }
-      for (size_t n = 0; n < tx.vout.size(); ++n)
-      {
-        if (tx.rct_signatures.outPk[n].dest != boost::get<txout_to_key>(tx.vout[n].target).key)
-        {
-          LOG_PRINT_RED_L1("tx ringct public key does not match output public key for tx id= " << get_transaction_hash(tx));
-          return false;
-        }
-      }
     }
 
     if(!check_money_overflow(tx))