ringct: remove unused senderPk from ecdhTuple

This was an early ringct field, which was never used in production

src/cryptonote_basic/cryptonote_boost_serialization.h

@@ -262,7 +262,6 @@ namespace boost
       memset(&x.amount, 0, sizeof(x.amount));
     }
     a & amount;
-    // a & x.senderPk; // not serialized, as we do not use it in monero currently
   }
 
   template <class Archive>

src/ringct/rctTypes.h

@@ -120,17 +120,14 @@ namespace rct {
     // If the pedersen commitment to an amount is C = aG + bH,
     // "mask" contains a 32 byte key a
     // "amount" contains a hex representation (in 32 bytes) of a 64 bit number
-    // "senderPk" is not the senders actual public key, but a one-time public key generated for
     // the purpose of the ECDH exchange
     struct ecdhTuple {
         key mask;
         key amount;
-        key senderPk;
 
         BEGIN_SERIALIZE_OBJECT()
           FIELD(mask) // not saved from v2 BPs
           FIELD(amount)
-          // FIELD(senderPk) // not serialized, as we do not use it in monero currently
         END_SERIALIZE()
     };
 

tests/unit_tests/device.cpp

@@ -121,12 +121,10 @@ TEST(device, ecdh32)
   rct::key key = rct::skGen();
   tuple.mask = rct::skGen();
   tuple.amount = rct::skGen();
-  tuple.senderPk = rct::pkGen();
   tuple2 = tuple;
   dev.ecdhEncode(tuple, key, false);
   dev.ecdhDecode(tuple, key, false);
   ASSERT_EQ(tuple2.mask, tuple.mask);
   ASSERT_EQ(tuple2.amount, tuple.amount);
-  ASSERT_EQ(tuple2.senderPk, tuple.senderPk);
 }
 

tests/unit_tests/serialization.cpp

@@ -550,12 +550,10 @@ TEST(Serialization, serializes_ringct_types)
 
   ecdh0.mask = rct::skGen();
   ecdh0.amount = rct::skGen();
-  ecdh0.senderPk = rct::skGen();
   ASSERT_TRUE(serialization::dump_binary(ecdh0, blob));
   ASSERT_TRUE(serialization::parse_binary(blob, ecdh1));
   ASSERT_TRUE(!memcmp(&ecdh0.mask, &ecdh1.mask, sizeof(ecdh0.mask)));
   ASSERT_TRUE(!memcmp(&ecdh0.amount, &ecdh1.amount, sizeof(ecdh0.amount)));
-  // senderPk is not serialized
 
   for (size_t n = 0; n < 64; ++n)
   {