From 54c15e7161027bdf56d3f360b96479b64ea2e395 Mon Sep 17 00:00:00 2001
From: furszy <matiasfurszyfer@protonmail.com>
Date: Tue, 8 Dec 2020 15:05:55 -0300
Subject: [PATCH] [Test] Adding sapling transaction validation unit test
 coverage.

---
 src/test/CMakeLists.txt       |  1 +
 src/test/validation_tests.cpp | 95 +++++++++++++++++++++++++++++++++++
 2 files changed, 96 insertions(+)

diff --git a/src/test/CMakeLists.txt b/src/test/CMakeLists.txt
index 51aa21c3ca00..4a420606f5ed 100644
--- a/src/test/CMakeLists.txt
+++ b/src/test/CMakeLists.txt
@@ -127,6 +127,7 @@ set(BITCOIN_TESTS
         ${CMAKE_CURRENT_SOURCE_DIR}/uint256_tests.cpp
         ${CMAKE_CURRENT_SOURCE_DIR}/univalue_tests.cpp
         ${CMAKE_CURRENT_SOURCE_DIR}/util_tests.cpp
+        ${CMAKE_CURRENT_SOURCE_DIR}/validation_tests.cpp
         ${CMAKE_CURRENT_SOURCE_DIR}/sha256compress_tests.cpp
         ${CMAKE_CURRENT_SOURCE_DIR}/upgrades_tests.cpp
         ${CMAKE_CURRENT_SOURCE_DIR}/librust/sapling_rpc_wallet_tests.cpp
diff --git a/src/test/validation_tests.cpp b/src/test/validation_tests.cpp
index 56fee4d2da40..ad7be364874d 100644
--- a/src/test/validation_tests.cpp
+++ b/src/test/validation_tests.cpp
@@ -4,6 +4,7 @@
 
 #include "test/test_pivx.h"
 #include "primitives/transaction.h"
+#include "sapling/sapling_validation.h"
 #include "tiertwo/specialtx_validation.h"
 #include "test/librust/utiltest.h"
 
@@ -58,4 +59,98 @@ BOOST_AUTO_TEST_CASE(special_tx_validation_test)
     RegtestDeactivateSapling();
 }
 
+void test_simple_sapling_invalidity(CMutableTransaction& tx)
+{
+    CAmount nDummyValueOut;
+    {
+        CMutableTransaction newTx(tx);
+        CValidationState state;
+
+        BOOST_CHECK(!CheckTransaction(newTx, false, false, state, false));
+        BOOST_CHECK(state.GetRejectReason() == "bad-txns-vin-empty");
+    }
+    {
+        CMutableTransaction newTx(tx);
+        CValidationState state;
+
+        newTx.sapData->vShieldedSpend.emplace_back();
+        newTx.sapData->vShieldedSpend[0].nullifier = GetRandHash();
+
+        BOOST_CHECK(!CheckTransaction(newTx, false, false, state, false));
+        BOOST_CHECK(state.GetRejectReason() == "bad-txns-vout-empty");
+    }
+    {
+        // Ensure that nullifiers are never duplicated within a transaction.
+        CMutableTransaction newTx(tx);
+        CValidationState state;
+
+        newTx.sapData->vShieldedSpend.emplace_back();
+        newTx.sapData->vShieldedSpend[0].nullifier = GetRandHash();
+
+        newTx.sapData->vShieldedOutput.emplace_back();
+
+        newTx.sapData->vShieldedSpend.emplace_back();
+        newTx.sapData->vShieldedSpend[1].nullifier = newTx.sapData->vShieldedSpend[0].nullifier;
+
+        BOOST_CHECK(!SaplingValidation::CheckTransactionWithoutProofVerification(newTx, state, nDummyValueOut));
+        BOOST_CHECK(state.GetRejectReason() == "bad-spend-description-nullifiers-duplicate");
+
+        newTx.sapData->vShieldedSpend[1].nullifier = GetRandHash();
+
+        BOOST_CHECK(SaplingValidation::CheckTransactionWithoutProofVerification(newTx, state, nDummyValueOut));
+    }
+    {
+        CMutableTransaction newTx(tx);
+        CValidationState state;
+
+        // Create a coinbase transaction
+        CTxIn vin;
+        vin.prevout = COutPoint();
+        newTx.vin.emplace_back(vin);
+        CTxOut vout;
+        vout.nValue = 2;
+        newTx.vout.emplace_back(vout);
+
+        newTx.sapData->vShieldedSpend.emplace_back();
+
+        BOOST_CHECK(!CheckTransaction(newTx, false, false, state, false, false, true));
+        BOOST_CHECK(state.GetRejectReason() == "bad-txns-invalid-sapling");
+    }
+    {
+        CMutableTransaction newTx(tx);
+        CValidationState state;
+
+        // Create a coinstake transaction
+        CTxIn vin;
+        vin.prevout = COutPoint(UINT256_ZERO, 0);
+        newTx.vin.emplace_back(vin);
+        CTxOut vout;
+        vout.nValue = 0;
+        newTx.vout.emplace_back(vout);
+        vout.nValue = 2;
+        newTx.vout.emplace_back(vout);
+
+        newTx.sapData->vShieldedSpend.emplace_back();
+
+        BOOST_CHECK(!CheckTransaction(newTx, false, false, state, false, false, true));
+        BOOST_CHECK(state.GetRejectReason() == "bad-txns-invalid-sapling");
+    }
+}
+
+BOOST_AUTO_TEST_CASE(test_simple_shielded_invalid)
+{
+    // Switch to regtest parameters so we can activate Sapling
+    SelectParams(CBaseChainParams::REGTEST);
+
+    CMutableTransaction mtx;
+    mtx.nVersion = CTransaction::TxVersion::SAPLING;
+
+    UpdateNetworkUpgradeParameters(Consensus::UPGRADE_V5_0, Consensus::NetworkUpgrade::ALWAYS_ACTIVE);
+    test_simple_sapling_invalidity(mtx);
+    UpdateNetworkUpgradeParameters(Consensus::UPGRADE_V5_0, Consensus::NetworkUpgrade::NO_ACTIVATION_HEIGHT);
+
+    // Switch back to mainnet parameters as originally selected in test fixture
+    SelectParams(CBaseChainParams::MAIN);
+}
+
 BOOST_AUTO_TEST_SUITE_END()