From 47c0c653266ab533e82401f00bfc9648d06b3e8f Mon Sep 17 00:00:00 2001 From: Jack Grigg Date: Fri, 23 Oct 2020 19:12:43 +0100 Subject: [PATCH] Improve reject reasons for unmet shielded requirements These reject messages end up bubbling up to users via the RPC interface. Distinguishing between the various failure cases will help users figure out why their transaction is being rejected. Uses operator* instead of std::optional::value because the latter was introduced in macOS 10.14, and our current minimum is 10.12. Closes zcash/zcash#3114. --- src/coins.cpp | 15 +++++++------- src/coins.h | 10 ++++++++- src/main.cpp | 57 +++++++++++++++++++++++++++++++++++++++++---------- 3 files changed, 63 insertions(+), 19 deletions(-) diff --git a/src/coins.cpp b/src/coins.cpp index f2999df13..0145c225f 100644 --- a/src/coins.cpp +++ b/src/coins.cpp @@ -914,7 +914,7 @@ CAmount CCoinsViewCache::GetValueIn(const CTransaction& tx) const return nResult; } -bool CCoinsViewCache::HaveShieldedRequirements(const CTransaction& tx) const +std::optional CCoinsViewCache::HaveShieldedRequirements(const CTransaction& tx) const { boost::unordered_map intermediates; @@ -925,7 +925,7 @@ bool CCoinsViewCache::HaveShieldedRequirements(const CTransaction& tx) const if (GetNullifier(nullifier, SPROUT)) { // If the nullifier is set, this transaction // double-spends! - return false; + return UnsatisfiedShieldedReq::SproutDuplicateNullifier; } } @@ -934,7 +934,7 @@ bool CCoinsViewCache::HaveShieldedRequirements(const CTransaction& tx) const if (it != intermediates.end()) { tree = it->second; } else if (!GetSproutAnchorAt(joinsplit.anchor, tree)) { - return false; + return UnsatisfiedShieldedReq::SproutUnknownAnchor; } BOOST_FOREACH(const uint256& commitment, joinsplit.commitments) @@ -946,16 +946,17 @@ bool CCoinsViewCache::HaveShieldedRequirements(const CTransaction& tx) const } for (const SpendDescription &spendDescription : tx.vShieldedSpend) { - if (GetNullifier(spendDescription.nullifier, SAPLING)) // Prevent double spends - return false; + if (GetNullifier(spendDescription.nullifier, SAPLING)) { // Prevent double spends + return UnsatisfiedShieldedReq::SaplingDuplicateNullifier; + } SaplingMerkleTree tree; if (!GetSaplingAnchorAt(spendDescription.anchor, tree)) { - return false; + return UnsatisfiedShieldedReq::SaplingUnknownAnchor; } } - return true; + return std::nullopt; } bool CCoinsViewCache::HaveInputs(const CTransaction& tx) const diff --git a/src/coins.h b/src/coins.h index 10999e8d9..67cba90e8 100644 --- a/src/coins.h +++ b/src/coins.h @@ -447,6 +447,14 @@ public: friend class CCoinsViewCache; }; +/** The set of shielded requirements that might be unsatisfied. */ +enum class UnsatisfiedShieldedReq { + SproutDuplicateNullifier, + SproutUnknownAnchor, + SaplingDuplicateNullifier, + SaplingUnknownAnchor, +}; + /** CCoinsView that adds a memory cache for transactions to another CCoinsView */ class CCoinsViewCache : public CCoinsViewBacked { @@ -566,7 +574,7 @@ public: bool HaveInputs(const CTransaction& tx) const; //! Check whether all joinsplit and sapling spend requirements (anchors/nullifiers) are satisfied - bool HaveShieldedRequirements(const CTransaction& tx) const; + std::optional HaveShieldedRequirements(const CTransaction& tx) const; //! Return priority of tx at height nHeight double GetPriority(const CTransaction &tx, int nHeight) const; diff --git a/src/main.cpp b/src/main.cpp index 2d43a1263..4fe2df808 100644 --- a/src/main.cpp +++ b/src/main.cpp @@ -117,6 +117,28 @@ const string strMessageMagic = "Zcash Signed Message:\n"; // Internal stuff namespace { + unsigned char ShieldedReqRejectCode(UnsatisfiedShieldedReq shieldedReq) + { + switch (shieldedReq) { + case UnsatisfiedShieldedReq::SproutDuplicateNullifier: + case UnsatisfiedShieldedReq::SaplingDuplicateNullifier: + return REJECT_DUPLICATE; + case UnsatisfiedShieldedReq::SproutUnknownAnchor: + case UnsatisfiedShieldedReq::SaplingUnknownAnchor: + return REJECT_INVALID; + } + } + + std::string ShieldedReqRejectReason(UnsatisfiedShieldedReq shieldedReq) + { + switch (shieldedReq) { + case UnsatisfiedShieldedReq::SproutDuplicateNullifier: return "bad-txns-sprout-duplicate-nullifier"; + case UnsatisfiedShieldedReq::SproutUnknownAnchor: return "bad-txns-sprout-unknown-anchor"; + case UnsatisfiedShieldedReq::SaplingDuplicateNullifier: return "bad-txns-sapling-duplicate-nullifier"; + case UnsatisfiedShieldedReq::SaplingUnknownAnchor: return "bad-txns-sapling-unknown-anchor"; + } + } + /** Abort with a message */ bool AbortNode(const std::string& strMessage, const std::string& userMessage="") { @@ -1542,10 +1564,14 @@ bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState &state, const CTransa return state.Invalid(error("AcceptToMemoryPool: inputs already spent"), REJECT_DUPLICATE, "bad-txns-inputs-spent"); - // are the joinsplits' and sapling spends' requirements met in tx(valid anchors/nullifiers)? - if (!view.HaveShieldedRequirements(tx)) - return state.Invalid(error("AcceptToMemoryPool: shielded requirements not met"), - REJECT_DUPLICATE, "bad-txns-shielded-requirements-not-met"); + // Are the shielded spends' requirements met? + auto unmetShieldedReq = view.HaveShieldedRequirements(tx); + if (unmetShieldedReq) { + auto rejectCode = ShieldedReqRejectCode(*unmetShieldedReq); + auto rejectReason = ShieldedReqRejectReason(*unmetShieldedReq); + return state.Invalid(error("AcceptToMemoryPool: shielded requirements not met (%s)", rejectReason), + rejectCode, rejectReason); + } // Bring the best block into scope view.GetBestBlock(); @@ -2176,9 +2202,14 @@ bool CheckTxInputs(const CTransaction& tx, CValidationState& state, const CCoins if (!inputs.HaveInputs(tx)) return state.Invalid(error("CheckInputs(): %s inputs unavailable", tx.GetHash().ToString())); - // are the JoinSplit's requirements met? - if (!inputs.HaveShieldedRequirements(tx)) - return state.Invalid(error("CheckInputs(): %s JoinSplit requirements not met", tx.GetHash().ToString())); + // Are the shielded spends' requirements met? + auto unmetShieldedReq = inputs.HaveShieldedRequirements(tx); + if (unmetShieldedReq) { + auto rejectCode = ShieldedReqRejectCode(*unmetShieldedReq); + auto rejectReason = ShieldedReqRejectReason(*unmetShieldedReq); + return state.Invalid(error("CheckInputs(): %s shielded requirements not met (%s)", tx.GetHash().ToString(), rejectReason), + rejectCode, rejectReason); + } CAmount nValueIn = 0; CAmount nFees = 0; @@ -2861,10 +2892,14 @@ bool ConnectBlock(const CBlock& block, CValidationState& state, CBlockIndex* pin return state.DoS(100, error("ConnectBlock(): inputs missing/spent"), REJECT_INVALID, "bad-txns-inputs-missingorspent"); - // are the JoinSplit's requirements met? - if (!view.HaveShieldedRequirements(tx)) - return state.DoS(100, error("ConnectBlock(): JoinSplit requirements not met"), - REJECT_INVALID, "bad-txns-joinsplit-requirements-not-met"); + // Are the shielded spends' requirements met? + auto unmetShieldedReq = view.HaveShieldedRequirements(tx); + if (unmetShieldedReq) { + auto rejectCode = ShieldedReqRejectCode(*unmetShieldedReq); + auto rejectReason = ShieldedReqRejectReason(*unmetShieldedReq); + return state.DoS(100, error("ConnectBlock(): shielded requirements not met (%s)", rejectReason), + rejectCode, rejectReason); + } // insightexplorer // https://github.com/bitpay/bitcoin/commit/017f548ea6d89423ef568117447e61dd5707ec42#diff-7ec3c68a81efff79b6ca22ac1f1eabbaR2597