ringct: encode 8 byte amount, saving 24 bytes per output

Found by knaccc

3 files changed, 22 insertions, 6 deletions

diff --git a/tests/core_tests/multisig.cpp b/tests/core_tests/multisig.cpp
index 7dd6a89e2..37fda6643 100644
--- a/tests/core_tests/multisig.cpp
+++ b/tests/core_tests/multisig.cpp
@@ -455,7 +455,7 @@ bool gen_multisig_tx_validation_base::generate_with(std::vector<test_event_entry
       crypto::secret_key scalar1;
       crypto::derivation_to_scalar(derivation, n, scalar1);
       rct::ecdhTuple ecdh_info = tx.rct_signatures.ecdhInfo[n];
-      rct::ecdhDecode(ecdh_info, rct::sk2rct(scalar1));
+      rct::ecdhDecode(ecdh_info, rct::sk2rct(scalar1), tx.rct_signatures.type == rct::RCTTypeBulletproof2);
       rct::key C = tx.rct_signatures.outPk[n].mask;
       rct::addKeys2(Ctmp, ecdh_info.mask, ecdh_info.amount, rct::H);
       CHECK_AND_ASSERT_MES(rct::equalKeys(C, Ctmp), false, "Failed to decode amount");
diff --git a/tests/unit_tests/device.cpp b/tests/unit_tests/device.cpp
index 50ccec9fa..3ae748145 100644
--- a/tests/unit_tests/device.cpp
+++ b/tests/unit_tests/device.cpp
@@ -114,7 +114,7 @@ TEST(device, ops)
   ASSERT_EQ(ki0, ki1);
 }
 
-TEST(device, ecdh)
+TEST(device, ecdh32)
 {
   hw::core::device_default dev;
   rct::ecdhTuple tuple, tuple2;
@@ -123,8 +123,24 @@ TEST(device, ecdh)
   tuple.amount = rct::skGen();
   tuple.senderPk = rct::pkGen();
   tuple2 = tuple;
-  dev.ecdhEncode(tuple, key);
-  dev.ecdhDecode(tuple, key);
+  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);
+}
+
+TEST(device, ecdh8)
+{
+  hw::core::device_default dev;
+  rct::ecdhTuple tuple, tuple2;
+  rct::key key = rct::skGen();
+  tuple.mask = rct::skGen();
+  tuple.amount = rct::skGen();
+  tuple.senderPk = rct::pkGen();
+  tuple2 = tuple;
+  dev.ecdhEncode(tuple, key, true);
+  dev.ecdhDecode(tuple, key, true);
   ASSERT_EQ(tuple2.mask, tuple.mask);
   ASSERT_EQ(tuple2.amount, tuple.amount);
   ASSERT_EQ(tuple2.senderPk, tuple.senderPk);
diff --git a/tests/unit_tests/ringct.cpp b/tests/unit_tests/ringct.cpp
index ec704daa1..905b8471a 100644
--- a/tests/unit_tests/ringct.cpp
+++ b/tests/unit_tests/ringct.cpp
@@ -843,8 +843,8 @@ TEST(ringct, ecdh_roundtrip)
     t0.amount = d2h(amount);
 
     t1 = t0;
-    ecdhEncode(t1, k);
-    ecdhDecode(t1, k);
+    ecdhEncode(t1, k, true);
+    ecdhDecode(t1, k, true);
     ASSERT_TRUE(t0.mask == t1.mask);
     ASSERT_TRUE(equalKeys(t0.mask, t1.mask));
     ASSERT_TRUE(t0.amount == t1.amount);