Auto merge of #4812 - str4d:shielded-reqs-reject-reasons, r=str4d

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.

Closes zcash/zcash#3114.
This commit is contained in:
Homu 2020-10-27 01:35:14 +00:00
commit b9a4f291ea
4 changed files with 102 additions and 24 deletions

View File

@ -11,6 +11,8 @@
#include <assert.h>
#include <tracing.h>
/**
* calculate number of bytes for the bitmask, and its number of non-zero bytes
* each bit in the bitmask represents the availability of one output, but the
@ -914,7 +916,7 @@ CAmount CCoinsViewCache::GetValueIn(const CTransaction& tx) const
return nResult;
}
bool CCoinsViewCache::HaveShieldedRequirements(const CTransaction& tx) const
std::optional<UnsatisfiedShieldedReq> CCoinsViewCache::HaveShieldedRequirements(const CTransaction& tx) const
{
boost::unordered_map<uint256, SproutMerkleTree, CCoinsKeyHasher> intermediates;
@ -925,7 +927,12 @@ bool CCoinsViewCache::HaveShieldedRequirements(const CTransaction& tx) const
if (GetNullifier(nullifier, SPROUT)) {
// If the nullifier is set, this transaction
// double-spends!
return false;
auto txid = tx.GetHash().ToString();
auto nf = nullifier.ToString();
TracingWarn("consensus", "Sprout double-spend detected",
"txid", txid.c_str(),
"nf", nf.c_str());
return UnsatisfiedShieldedReq::SproutDuplicateNullifier;
}
}
@ -934,7 +941,12 @@ bool CCoinsViewCache::HaveShieldedRequirements(const CTransaction& tx) const
if (it != intermediates.end()) {
tree = it->second;
} else if (!GetSproutAnchorAt(joinsplit.anchor, tree)) {
return false;
auto txid = tx.GetHash().ToString();
auto anchor = joinsplit.anchor.ToString();
TracingWarn("consensus", "Transaction uses unknown Sprout anchor",
"txid", txid.c_str(),
"anchor", anchor.c_str());
return UnsatisfiedShieldedReq::SproutUnknownAnchor;
}
BOOST_FOREACH(const uint256& commitment, joinsplit.commitments)
@ -946,16 +958,27 @@ 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
auto txid = tx.GetHash().ToString();
auto nf = spendDescription.nullifier.ToString();
TracingWarn("consensus", "Sapling double-spend detected",
"txid", txid.c_str(),
"nf", nf.c_str());
return UnsatisfiedShieldedReq::SaplingDuplicateNullifier;
}
SaplingMerkleTree tree;
if (!GetSaplingAnchorAt(spendDescription.anchor, tree)) {
return false;
auto txid = tx.GetHash().ToString();
auto anchor = spendDescription.anchor.ToString();
TracingWarn("consensus", "Transaction uses unknown Sapling anchor",
"txid", txid.c_str(),
"anchor", anchor.c_str());
return UnsatisfiedShieldedReq::SaplingUnknownAnchor;
}
}
return true;
return std::nullopt;
}
bool CCoinsViewCache::HaveInputs(const CTransaction& tx) const

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@ -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<UnsatisfiedShieldedReq> HaveShieldedRequirements(const CTransaction& tx) const;
//! Return priority of tx at height nHeight
double GetPriority(const CTransaction &tx, int nHeight) const;

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@ -115,6 +115,28 @@ 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="")
{
@ -1540,10 +1562,18 @@ 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 txid = tx.GetHash().ToString();
auto rejectCode = ShieldedReqRejectCode(*unmetShieldedReq);
auto rejectReason = ShieldedReqRejectReason(*unmetShieldedReq);
TracingError(
"main", "AcceptToMemoryPool(): shielded requirements not met",
"txid", txid.c_str(),
"reason", rejectReason.c_str());
return state.Invalid(false, rejectCode, rejectReason);
}
// Bring the best block into scope
view.GetBestBlock();
@ -2174,9 +2204,18 @@ 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 txid = tx.GetHash().ToString();
auto rejectCode = ShieldedReqRejectCode(*unmetShieldedReq);
auto rejectReason = ShieldedReqRejectReason(*unmetShieldedReq);
TracingError(
"main", "CheckInputs(): shielded requirements not met",
"txid", txid.c_str(),
"reason", rejectReason.c_str());
return state.Invalid(false, rejectCode, rejectReason);
}
CAmount nValueIn = 0;
CAmount nFees = 0;
@ -2859,10 +2898,18 @@ 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 txid = tx.GetHash().ToString();
auto rejectCode = ShieldedReqRejectCode(*unmetShieldedReq);
auto rejectReason = ShieldedReqRejectReason(*unmetShieldedReq);
TracingError(
"main", "ConnectBlock(): shielded requirements not met",
"txid", txid.c_str(),
"reason", rejectReason.c_str());
return state.DoS(100, false, rejectCode, rejectReason);
}
// insightexplorer
// https://github.com/bitpay/bitcoin/commit/017f548ea6d89423ef568117447e61dd5707ec42#diff-7ec3c68a81efff79b6ca22ac1f1eabbaR2597

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@ -644,7 +644,7 @@ BOOST_AUTO_TEST_CASE(chained_joinsplits)
CMutableTransaction mtx;
mtx.vJoinSplit.push_back(js2);
BOOST_CHECK(!cache.HaveShieldedRequirements(mtx));
BOOST_CHECK(cache.HaveShieldedRequirements(mtx) == std::optional(UnsatisfiedShieldedReq::SproutUnknownAnchor));
}
{
@ -654,7 +654,7 @@ BOOST_AUTO_TEST_CASE(chained_joinsplits)
mtx.vJoinSplit.push_back(js2);
mtx.vJoinSplit.push_back(js1);
BOOST_CHECK(!cache.HaveShieldedRequirements(mtx));
BOOST_CHECK(cache.HaveShieldedRequirements(mtx) == std::optional(UnsatisfiedShieldedReq::SproutUnknownAnchor));
}
{
@ -662,7 +662,7 @@ BOOST_AUTO_TEST_CASE(chained_joinsplits)
mtx.vJoinSplit.push_back(js1);
mtx.vJoinSplit.push_back(js2);
BOOST_CHECK(cache.HaveShieldedRequirements(mtx));
BOOST_CHECK(cache.HaveShieldedRequirements(mtx) == std::nullopt);
}
{
@ -671,7 +671,7 @@ BOOST_AUTO_TEST_CASE(chained_joinsplits)
mtx.vJoinSplit.push_back(js2);
mtx.vJoinSplit.push_back(js3);
BOOST_CHECK(cache.HaveShieldedRequirements(mtx));
BOOST_CHECK(cache.HaveShieldedRequirements(mtx) == std::nullopt);
}
{
@ -681,7 +681,7 @@ BOOST_AUTO_TEST_CASE(chained_joinsplits)
mtx.vJoinSplit.push_back(js2);
mtx.vJoinSplit.push_back(js3);
BOOST_CHECK(cache.HaveShieldedRequirements(mtx));
BOOST_CHECK(cache.HaveShieldedRequirements(mtx) == std::nullopt);
}
}