ringct: pseudoOuts moved to prunable in the simple bulletproof case

Saves 64 bytes non prunable data per typical tx

This breaks v7 consensus, will require a testnet reorg from v6

src/cryptonote_basic/cryptonote_boost_serialization.h

@@ -299,7 +299,7 @@ namespace boost
       throw boost::archive::archive_exception(boost::archive::archive_exception::other_exception, "Unsupported rct type");
     // a & x.message; message is not serialized, as it can be reconstructed from the tx data
     // a & x.mixRing; mixRing is not serialized, as it can be reconstructed from the offsets
-    if (x.type == rct::RCTTypeSimple || x.type == rct::RCTTypeSimpleBulletproof)
+    if (x.type == rct::RCTTypeSimple) // moved to prunable with bulletproofs
       a & x.pseudoOuts;
     a & x.ecdhInfo;
     serializeOutPk(a, x.outPk, ver);
@@ -313,6 +313,8 @@ namespace boost
     if (x.rangeSigs.empty())
       a & x.bulletproofs;
     a & x.MGs;
+    if (x.rangeSigs.empty())
+      a & x.pseudoOuts;
   }
 
   template <class Archive>
@@ -325,7 +327,7 @@ namespace boost
       throw boost::archive::archive_exception(boost::archive::archive_exception::other_exception, "Unsupported rct type");
     // a & x.message; message is not serialized, as it can be reconstructed from the tx data
     // a & x.mixRing; mixRing is not serialized, as it can be reconstructed from the offsets
-    if (x.type == rct::RCTTypeSimple || x.type == rct::RCTTypeSimpleBulletproof)
+    if (x.type == rct::RCTTypeSimple)
       a & x.pseudoOuts;
     a & x.ecdhInfo;
     serializeOutPk(a, x.outPk, ver);
@@ -335,6 +337,8 @@ namespace boost
     if (x.p.rangeSigs.empty())
       a & x.p.bulletproofs;
     a & x.p.MGs;
+    if (x.type == rct::RCTTypeSimpleBulletproof)
+      a & x.p.pseudoOuts;
   }
 }
 }

src/ringct/rctSigs.cpp

@@ -43,6 +43,30 @@ using namespace std;
 #define MONERO_DEFAULT_LOG_CATEGORY "ringct"
 
 namespace rct {
+    bool is_simple(int type)
+    {
+        switch (type)
+        {
+            case RCTTypeSimple:
+            case RCTTypeSimpleBulletproof:
+                return true;
+            default:
+                return false;
+        }
+    }
+
+    bool is_bulletproof(int type)
+    {
+        switch (type)
+        {
+            case RCTTypeSimpleBulletproof:
+            case RCTTypeFullBulletproof:
+                return true;
+            default:
+                return false;
+        }
+    }
+
     Bulletproof proveRangeBulletproof(key &C, key &mask, uint64_t amount)
     {
         mask = rct::skGen();
@@ -357,7 +381,8 @@ namespace rct {
 
       std::stringstream ss;
       binary_archive<true> ba(ss);
-      const size_t inputs = rv.pseudoOuts.size();
+      CHECK_AND_ASSERT_THROW_MES(!rv.mixRing.empty(), "Empty mixRing");
+      const size_t inputs = is_simple(rv.type) ? rv.mixRing.size() : rv.mixRing[0].size();
       const size_t outputs = rv.ecdhInfo.size();
       CHECK_AND_ASSERT_THROW_MES(const_cast<rctSig&>(rv).serialize_rctsig_base(ba, inputs, outputs),
           "Failed to serialize rctSigBase");
@@ -750,25 +775,26 @@ namespace rct {
 //        TODO: unused ??
 //        key txnFeeKey = scalarmultH(d2h(rv.txnFee));
         rv.mixRing = mixRing;
-        rv.pseudoOuts.resize(inamounts.size());
+        keyV &pseudoOuts = bulletproof ? rv.p.pseudoOuts : rv.pseudoOuts;
+        pseudoOuts.resize(inamounts.size());
         rv.p.MGs.resize(inamounts.size());
         key sumpouts = zero(); //sum pseudoOut masks
         keyV a(inamounts.size());
         for (i = 0 ; i < inamounts.size() - 1; i++) {
             skGen(a[i]);
             sc_add(sumpouts.bytes, a[i].bytes, sumpouts.bytes);
-            genC(rv.pseudoOuts[i], a[i], inamounts[i]);
+            genC(pseudoOuts[i], a[i], inamounts[i]);
         }
         rv.mixRing = mixRing;
         sc_sub(a[i].bytes, sumout.bytes, sumpouts.bytes);
-        genC(rv.pseudoOuts[i], a[i], inamounts[i]);
+        genC(pseudoOuts[i], a[i], inamounts[i]);
-        DP(rv.pseudoOuts[i]);
+        DP(pseudoOuts[i]);
 
         key full_message = get_pre_mlsag_hash(rv);
         if (msout)
           msout->c.resize(inamounts.size());
         for (i = 0 ; i < inamounts.size(); i++) {
-            rv.p.MGs[i] = proveRctMGSimple(full_message, rv.mixRing[i], inSk[i], a[i], rv.pseudoOuts[i], kLRki ? &(*kLRki)[i]: NULL, msout ? &msout->c[i] : NULL, index[i]);
+            rv.p.MGs[i] = proveRctMGSimple(full_message, rv.mixRing[i], inSk[i], a[i], pseudoOuts[i], kLRki ? &(*kLRki)[i]: NULL, msout ? &msout->c[i] : NULL, index[i]);
         }
         return rv;
     }
@@ -876,15 +902,25 @@ namespace rct {
         if (semantics)
         {
           if (rv.type == RCTTypeSimpleBulletproof)
+          {
             CHECK_AND_ASSERT_MES(rv.outPk.size() == rv.p.bulletproofs.size(), false, "Mismatched sizes of outPk and rv.p.bulletproofs");
+            CHECK_AND_ASSERT_MES(rv.p.pseudoOuts.size() == rv.p.MGs.size(), false, "Mismatched sizes of rv.p.pseudoOuts and rv.p.MGs");
+            CHECK_AND_ASSERT_MES(rv.pseudoOuts.empty(), false, "rv.pseudoOuts is not empty");
+          }
           else
+          {
             CHECK_AND_ASSERT_MES(rv.outPk.size() == rv.p.rangeSigs.size(), false, "Mismatched sizes of outPk and rv.p.rangeSigs");
-          CHECK_AND_ASSERT_MES(rv.outPk.size() == rv.ecdhInfo.size(), false, "Mismatched sizes of outPk and rv.ecdhInfo");
             CHECK_AND_ASSERT_MES(rv.pseudoOuts.size() == rv.p.MGs.size(), false, "Mismatched sizes of rv.pseudoOuts and rv.p.MGs");
+            CHECK_AND_ASSERT_MES(rv.p.pseudoOuts.empty(), false, "rv.p.pseudoOuts is not empty");
+          }
+          CHECK_AND_ASSERT_MES(rv.outPk.size() == rv.ecdhInfo.size(), false, "Mismatched sizes of outPk and rv.ecdhInfo");
         }
         else
         {
           // semantics check is early, and mixRing/MGs aren't resolved yet
+          if (rv.type == RCTTypeSimpleBulletproof)
+            CHECK_AND_ASSERT_MES(rv.p.pseudoOuts.size() == rv.mixRing.size(), false, "Mismatched sizes of rv.p.pseudoOuts and mixRing");
+          else
             CHECK_AND_ASSERT_MES(rv.pseudoOuts.size() == rv.mixRing.size(), false, "Mismatched sizes of rv.pseudoOuts and mixRing");
         }
 
@@ -894,6 +930,8 @@ namespace rct {
         tools::threadpool& tpool = tools::threadpool::getInstance();
         tools::threadpool::waiter waiter;
 
+        const keyV &pseudoOuts = is_bulletproof(rv.type) ? rv.p.pseudoOuts : rv.pseudoOuts;
+
         if (semantics) {
           key sumOutpks = identity();
           for (size_t i = 0; i < rv.outPk.size(); i++) {
@@ -904,8 +942,8 @@ namespace rct {
           addKeys(sumOutpks, txnFeeKey, sumOutpks);
 
           key sumPseudoOuts = identity();
-          for (size_t i = 0 ; i < rv.pseudoOuts.size() ; i++) {
+          for (size_t i = 0 ; i < pseudoOuts.size() ; i++) {
-              addKeys(sumPseudoOuts, sumPseudoOuts, rv.pseudoOuts[i]);
+              addKeys(sumPseudoOuts, sumPseudoOuts, pseudoOuts[i]);
           }
           DP(sumPseudoOuts);
 
@@ -941,7 +979,7 @@ namespace rct {
           results.resize(rv.mixRing.size());
           for (size_t i = 0 ; i < rv.mixRing.size() ; i++) {
             tpool.submit(&waiter, [&, i] {
-                results[i] = verRctMGSimple(message, rv.p.MGs[i], rv.mixRing[i], rv.pseudoOuts[i]);
+                results[i] = verRctMGSimple(message, rv.p.MGs[i], rv.mixRing[i], pseudoOuts[i]);
             });
           }
           waiter.wait();

src/ringct/rctTypes.h

@@ -246,7 +246,7 @@ namespace rct {
           // inputs/outputs not saved, only here for serialization help
           // FIELD(message) - not serialized, it can be reconstructed
           // FIELD(mixRing) - not serialized, it can be reconstructed
-          if (type == RCTTypeSimple || type == RCTTypeSimpleBulletproof)
+          if (type == RCTTypeSimple) // moved to prunable with bulletproofs
           {
             ar.tag("pseudoOuts");
             ar.begin_array();
@@ -294,6 +294,7 @@ namespace rct {
         std::vector<rangeSig> rangeSigs;
         std::vector<Bulletproof> bulletproofs;
         std::vector<mgSig> MGs; // simple rct has N, full has 1
+        keyV pseudoOuts; //C - for simple rct
 
         template<bool W, template <bool> class Archive>
         bool serialize_rctsig_prunable(Archive<W> &ar, uint8_t type, size_t inputs, size_t outputs, size_t mixin)
@@ -381,6 +382,21 @@ namespace rct {
                ar.delimit_array();
           }
           ar.end_array();
+          if (type == RCTTypeSimpleBulletproof)
+          {
+            ar.tag("pseudoOuts");
+            ar.begin_array();
+            PREPARE_CUSTOM_VECTOR_SERIALIZATION(inputs, pseudoOuts);
+            if (pseudoOuts.size() != inputs)
+              return false;
+            for (size_t i = 0; i < inputs; ++i)
+            {
+              FIELDS(pseudoOuts[i])
+              if (inputs - i > 1)
+                ar.delimit_array();
+            }
+            ar.end_array();
+          }
           return true;
         }