MOVEONLY: tx functions to consensus/tx_verify.o

Functions related to transaction verification.

13 files changed, 336 insertions, 297 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
index 8680546b99..401705bafa 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -95,6 +95,7 @@ BITCOIN_CORE_H = \
   compat/sanity.h \
   compressor.h \
   consensus/consensus.h \
+  consensus/tx_verify.h \
   core_io.h \
   core_memusage.h \
   cuckoocache.h \
@@ -183,6 +184,7 @@ libbitcoin_server_a_SOURCES = \
   blockencodings.cpp \
   chain.cpp \
   checkpoints.cpp \
+  consensus/tx_verify.cpp \
   httprpc.cpp \
   httpserver.cpp \
   init.cpp \
diff --git a/src/consensus/tx_verify.cpp b/src/consensus/tx_verify.cpp
new file mode 100644
index 0000000000..043f4cf95c
--- /dev/null
+++ b/src/consensus/tx_verify.cpp
@@ -0,0 +1,246 @@
+// Copyright (c) 2017-2017 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include "tx_verify.h"
+
+#include "consensus.h"
+#include "primitives/transaction.h"
+#include "script/interpreter.h"
+#include "validation.h"
+
+// TODO remove the following dependencies
+#include "chain.h"
+#include "coins.h"
+#include "utilmoneystr.h"
+ 
+bool IsFinalTx(const CTransaction &tx, int nBlockHeight, int64_t nBlockTime)
+{
+    if (tx.nLockTime == 0)
+        return true;
+    if ((int64_t)tx.nLockTime < ((int64_t)tx.nLockTime < LOCKTIME_THRESHOLD ? (int64_t)nBlockHeight : nBlockTime))
+        return true;
+    for (const auto& txin : tx.vin) {
+        if (!(txin.nSequence == CTxIn::SEQUENCE_FINAL))
+            return false;
+    }
+    return true;
+}
+
+std::pair<int, int64_t> CalculateSequenceLocks(const CTransaction &tx, int flags, std::vector<int>* prevHeights, const CBlockIndex& block)
+{
+    assert(prevHeights->size() == tx.vin.size());
+
+    // Will be set to the equivalent height- and time-based nLockTime
+    // values that would be necessary to satisfy all relative lock-
+    // time constraints given our view of block chain history.
+    // The semantics of nLockTime are the last invalid height/time, so
+    // use -1 to have the effect of any height or time being valid.
+    int nMinHeight = -1;
+    int64_t nMinTime = -1;
+
+    // tx.nVersion is signed integer so requires cast to unsigned otherwise
+    // we would be doing a signed comparison and half the range of nVersion
+    // wouldn't support BIP 68.
+    bool fEnforceBIP68 = static_cast<uint32_t>(tx.nVersion) >= 2
+                      && flags & LOCKTIME_VERIFY_SEQUENCE;
+
+    // Do not enforce sequence numbers as a relative lock time
+    // unless we have been instructed to
+    if (!fEnforceBIP68) {
+        return std::make_pair(nMinHeight, nMinTime);
+    }
+
+    for (size_t txinIndex = 0; txinIndex < tx.vin.size(); txinIndex++) {
+        const CTxIn& txin = tx.vin[txinIndex];
+
+        // Sequence numbers with the most significant bit set are not
+        // treated as relative lock-times, nor are they given any
+        // consensus-enforced meaning at this point.
+        if (txin.nSequence & CTxIn::SEQUENCE_LOCKTIME_DISABLE_FLAG) {
+            // The height of this input is not relevant for sequence locks
+            (*prevHeights)[txinIndex] = 0;
+            continue;
+        }
+
+        int nCoinHeight = (*prevHeights)[txinIndex];
+
+        if (txin.nSequence & CTxIn::SEQUENCE_LOCKTIME_TYPE_FLAG) {
+            int64_t nCoinTime = block.GetAncestor(std::max(nCoinHeight-1, 0))->GetMedianTimePast();
+            // NOTE: Subtract 1 to maintain nLockTime semantics
+            // BIP 68 relative lock times have the semantics of calculating
+            // the first block or time at which the transaction would be
+            // valid. When calculating the effective block time or height
+            // for the entire transaction, we switch to using the
+            // semantics of nLockTime which is the last invalid block
+            // time or height.  Thus we subtract 1 from the calculated
+            // time or height.
+
+            // Time-based relative lock-times are measured from the
+            // smallest allowed timestamp of the block containing the
+            // txout being spent, which is the median time past of the
+            // block prior.
+            nMinTime = std::max(nMinTime, nCoinTime + (int64_t)((txin.nSequence & CTxIn::SEQUENCE_LOCKTIME_MASK) << CTxIn::SEQUENCE_LOCKTIME_GRANULARITY) - 1);
+        } else {
+            nMinHeight = std::max(nMinHeight, nCoinHeight + (int)(txin.nSequence & CTxIn::SEQUENCE_LOCKTIME_MASK) - 1);
+        }
+    }
+
+    return std::make_pair(nMinHeight, nMinTime);
+}
+
+bool EvaluateSequenceLocks(const CBlockIndex& block, std::pair<int, int64_t> lockPair)
+{
+    assert(block.pprev);
+    int64_t nBlockTime = block.pprev->GetMedianTimePast();
+    if (lockPair.first >= block.nHeight || lockPair.second >= nBlockTime)
+        return false;
+
+    return true;
+}
+
+bool SequenceLocks(const CTransaction &tx, int flags, std::vector<int>* prevHeights, const CBlockIndex& block)
+{
+    return EvaluateSequenceLocks(block, CalculateSequenceLocks(tx, flags, prevHeights, block));
+}
+
+unsigned int GetLegacySigOpCount(const CTransaction& tx)
+{
+    unsigned int nSigOps = 0;
+    for (const auto& txin : tx.vin)
+    {
+        nSigOps += txin.scriptSig.GetSigOpCount(false);
+    }
+    for (const auto& txout : tx.vout)
+    {
+        nSigOps += txout.scriptPubKey.GetSigOpCount(false);
+    }
+    return nSigOps;
+}
+
+unsigned int GetP2SHSigOpCount(const CTransaction& tx, const CCoinsViewCache& inputs)
+{
+    if (tx.IsCoinBase())
+        return 0;
+
+    unsigned int nSigOps = 0;
+    for (unsigned int i = 0; i < tx.vin.size(); i++)
+    {
+        const CTxOut &prevout = inputs.GetOutputFor(tx.vin[i]);
+        if (prevout.scriptPubKey.IsPayToScriptHash())
+            nSigOps += prevout.scriptPubKey.GetSigOpCount(tx.vin[i].scriptSig);
+    }
+    return nSigOps;
+}
+
+int64_t GetTransactionSigOpCost(const CTransaction& tx, const CCoinsViewCache& inputs, int flags)
+{
+    int64_t nSigOps = GetLegacySigOpCount(tx) * WITNESS_SCALE_FACTOR;
+
+    if (tx.IsCoinBase())
+        return nSigOps;
+
+    if (flags & SCRIPT_VERIFY_P2SH) {
+        nSigOps += GetP2SHSigOpCount(tx, inputs) * WITNESS_SCALE_FACTOR;
+    }
+
+    for (unsigned int i = 0; i < tx.vin.size(); i++)
+    {
+        const CTxOut &prevout = inputs.GetOutputFor(tx.vin[i]);
+        nSigOps += CountWitnessSigOps(tx.vin[i].scriptSig, prevout.scriptPubKey, &tx.vin[i].scriptWitness, flags);
+    }
+    return nSigOps;
+}
+
+bool CheckTransaction(const CTransaction& tx, CValidationState &state, bool fCheckDuplicateInputs)
+{
+    // Basic checks that don't depend on any context
+    if (tx.vin.empty())
+        return state.DoS(10, false, REJECT_INVALID, "bad-txns-vin-empty");
+    if (tx.vout.empty())
+        return state.DoS(10, false, REJECT_INVALID, "bad-txns-vout-empty");
+    // Size limits (this doesn't take the witness into account, as that hasn't been checked for malleability)
+    if (::GetSerializeSize(tx, SER_NETWORK, PROTOCOL_VERSION | SERIALIZE_TRANSACTION_NO_WITNESS) > MAX_BLOCK_BASE_SIZE)
+        return state.DoS(100, false, REJECT_INVALID, "bad-txns-oversize");
+
+    // Check for negative or overflow output values
+    CAmount nValueOut = 0;
+    for (const auto& txout : tx.vout)
+    {
+        if (txout.nValue < 0)
+            return state.DoS(100, false, REJECT_INVALID, "bad-txns-vout-negative");
+        if (txout.nValue > MAX_MONEY)
+            return state.DoS(100, false, REJECT_INVALID, "bad-txns-vout-toolarge");
+        nValueOut += txout.nValue;
+        if (!MoneyRange(nValueOut))
+            return state.DoS(100, false, REJECT_INVALID, "bad-txns-txouttotal-toolarge");
+    }
+
+    // Check for duplicate inputs - note that this check is slow so we skip it in CheckBlock
+    if (fCheckDuplicateInputs) {
+        std::set<COutPoint> vInOutPoints;
+        for (const auto& txin : tx.vin)
+        {
+            if (!vInOutPoints.insert(txin.prevout).second)
+                return state.DoS(100, false, REJECT_INVALID, "bad-txns-inputs-duplicate");
+        }
+    }
+
+    if (tx.IsCoinBase())
+    {
+        if (tx.vin[0].scriptSig.size() < 2 || tx.vin[0].scriptSig.size() > 100)
+            return state.DoS(100, false, REJECT_INVALID, "bad-cb-length");
+    }
+    else
+    {
+        for (const auto& txin : tx.vin)
+            if (txin.prevout.IsNull())
+                return state.DoS(10, false, REJECT_INVALID, "bad-txns-prevout-null");
+    }
+
+    return true;
+}
+
+bool Consensus::CheckTxInputs(const CTransaction& tx, CValidationState& state, const CCoinsViewCache& inputs, int nSpendHeight)
+{
+        // This doesn't trigger the DoS code on purpose; if it did, it would make it easier
+        // for an attacker to attempt to split the network.
+        if (!inputs.HaveInputs(tx))
+            return state.Invalid(false, 0, "", "Inputs unavailable");
+
+        CAmount nValueIn = 0;
+        CAmount nFees = 0;
+        for (unsigned int i = 0; i < tx.vin.size(); i++)
+        {
+            const COutPoint &prevout = tx.vin[i].prevout;
+            const CCoins *coins = inputs.AccessCoins(prevout.hash);
+            assert(coins);
+
+            // If prev is coinbase, check that it's matured
+            if (coins->IsCoinBase()) {
+                if (nSpendHeight - coins->nHeight < COINBASE_MATURITY)
+                    return state.Invalid(false,
+                        REJECT_INVALID, "bad-txns-premature-spend-of-coinbase",
+                        strprintf("tried to spend coinbase at depth %d", nSpendHeight - coins->nHeight));
+            }
+
+            // Check for negative or overflow input values
+            nValueIn += coins->vout[prevout.n].nValue;
+            if (!MoneyRange(coins->vout[prevout.n].nValue) || !MoneyRange(nValueIn))
+                return state.DoS(100, false, REJECT_INVALID, "bad-txns-inputvalues-outofrange");
+
+        }
+
+        if (nValueIn < tx.GetValueOut())
+            return state.DoS(100, false, REJECT_INVALID, "bad-txns-in-belowout", false,
+                strprintf("value in (%s) < value out (%s)", FormatMoney(nValueIn), FormatMoney(tx.GetValueOut())));
+
+        // Tally transaction fees
+        CAmount nTxFee = nValueIn - tx.GetValueOut();
+        if (nTxFee < 0)
+            return state.DoS(100, false, REJECT_INVALID, "bad-txns-fee-negative");
+        nFees += nTxFee;
+        if (!MoneyRange(nFees))
+            return state.DoS(100, false, REJECT_INVALID, "bad-txns-fee-outofrange");
+    return true;
+}
diff --git a/src/consensus/tx_verify.h b/src/consensus/tx_verify.h
new file mode 100644
index 0000000000..d46d3294ca
--- /dev/null
+++ b/src/consensus/tx_verify.h
@@ -0,0 +1,78 @@
+// Copyright (c) 2017-2017 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_CONSENSUS_TX_VERIFY_H
+#define BITCOIN_CONSENSUS_TX_VERIFY_H
+
+#include <stdint.h>
+#include <vector>
+
+class CBlockIndex;
+class CCoinsViewCache;
+class CTransaction;
+class CValidationState;
+
+/** Transaction validation functions */
+
+/** Context-independent validity checks */
+bool CheckTransaction(const CTransaction& tx, CValidationState& state, bool fCheckDuplicateInputs=true);
+
+namespace Consensus {
+/**
+ * Check whether all inputs of this transaction are valid (no double spends and amounts)
+ * This does not modify the UTXO set. This does not check scripts and sigs.
+ * Preconditions: tx.IsCoinBase() is false.
+ */
+bool CheckTxInputs(const CTransaction& tx, CValidationState& state, const CCoinsViewCache& inputs, int nSpendHeight);
+} // namespace Consensus
+
+/** Auxiliary functions for transaction validation (ideally should not be exposed) */
+
+/**
+ * Count ECDSA signature operations the old-fashioned (pre-0.6) way
+ * @return number of sigops this transaction's outputs will produce when spent
+ * @see CTransaction::FetchInputs
+ */
+unsigned int GetLegacySigOpCount(const CTransaction& tx);
+
+/**
+ * Count ECDSA signature operations in pay-to-script-hash inputs.
+ * 
+ * @param[in] mapInputs Map of previous transactions that have outputs we're spending
+ * @return maximum number of sigops required to validate this transaction's inputs
+ * @see CTransaction::FetchInputs
+ */
+unsigned int GetP2SHSigOpCount(const CTransaction& tx, const CCoinsViewCache& mapInputs);
+
+/**
+ * Compute total signature operation cost of a transaction.
+ * @param[in] tx     Transaction for which we are computing the cost
+ * @param[in] inputs Map of previous transactions that have outputs we're spending
+ * @param[out] flags Script verification flags
+ * @return Total signature operation cost of tx
+ */
+int64_t GetTransactionSigOpCost(const CTransaction& tx, const CCoinsViewCache& inputs, int flags);
+
+/**
+ * Check if transaction is final and can be included in a block with the
+ * specified height and time. Consensus critical.
+ */
+bool IsFinalTx(const CTransaction &tx, int nBlockHeight, int64_t nBlockTime);
+
+/**
+ * Calculates the block height and previous block's median time past at
+ * which the transaction will be considered final in the context of BIP 68.
+ * Also removes from the vector of input heights any entries which did not
+ * correspond to sequence locked inputs as they do not affect the calculation.
+ */
+std::pair<int, int64_t> CalculateSequenceLocks(const CTransaction &tx, int flags, std::vector<int>* prevHeights, const CBlockIndex& block);
+
+bool EvaluateSequenceLocks(const CBlockIndex& block, std::pair<int, int64_t> lockPair);
+/**
+ * Check if transaction is final per BIP 68 sequence numbers and can be included in a block.
+ * Consensus critical. Takes as input a list of heights at which tx's inputs (in order) confirmed.
+ */
+bool SequenceLocks(const CTransaction &tx, int flags, std::vector<int>* prevHeights, const CBlockIndex& block);
+
+#endif // BITCOIN_CONSENSUS_TX_VERIFY_H
diff --git a/src/miner.cpp b/src/miner.cpp
index 386d75c4be..8f17c575cb 100644
--- a/src/miner.cpp
+++ b/src/miner.cpp
@@ -10,6 +10,7 @@
 #include "chainparams.h"
 #include "coins.h"
 #include "consensus/consensus.h"
+#include "consensus/tx_verify.h"
 #include "consensus/merkle.h"
 #include "consensus/validation.h"
 #include "hash.h"
diff --git a/src/test/miner_tests.cpp b/src/test/miner_tests.cpp
index 41f42c7b88..a9d69bb29e 100644
--- a/src/test/miner_tests.cpp
+++ b/src/test/miner_tests.cpp
@@ -6,6 +6,7 @@
 #include "coins.h"
 #include "consensus/consensus.h"
 #include "consensus/merkle.h"
+#include "consensus/tx_verify.h"
 #include "consensus/validation.h"
 #include "validation.h"
 #include "miner.h"
diff --git a/src/test/script_P2SH_tests.cpp b/src/test/script_P2SH_tests.cpp
index f8fd8cc30c..ede68f23d7 100644
--- a/src/test/script_P2SH_tests.cpp
+++ b/src/test/script_P2SH_tests.cpp
@@ -2,6 +2,7 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
+#include "consensus/tx_verify.h"
 #include "core_io.h"
 #include "key.h"
 #include "keystore.h"
diff --git a/src/test/sighash_tests.cpp b/src/test/sighash_tests.cpp
index 5279cb243b..2f7c22084e 100644
--- a/src/test/sighash_tests.cpp
+++ b/src/test/sighash_tests.cpp
@@ -2,10 +2,10 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
+#include "consensus/tx_verify.h"
 #include "consensus/validation.h"
 #include "data/sighash.json.h"
 #include "hash.h"
-#include "validation.h" // For CheckTransaction
 #include "script/interpreter.h"
 #include "script/script.h"
 #include "serialize.h"
diff --git a/src/test/sigopcount_tests.cpp b/src/test/sigopcount_tests.cpp
index 13d8911f03..92781d763d 100644
--- a/src/test/sigopcount_tests.cpp
+++ b/src/test/sigopcount_tests.cpp
@@ -2,7 +2,7 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#include "validation.h"
+#include "consensus/tx_verify.h"
 #include "pubkey.h"
 #include "key.h"
 #include "script/script.h"
diff --git a/src/test/transaction_tests.cpp b/src/test/transaction_tests.cpp
index 3b5da4980b..67610301d7 100644
--- a/src/test/transaction_tests.cpp
+++ b/src/test/transaction_tests.cpp
@@ -8,11 +8,12 @@
 
 #include "clientversion.h"
 #include "checkqueue.h"
+#include "consensus/tx_verify.h"
 #include "consensus/validation.h"
 #include "core_io.h"
 #include "key.h"
 #include "keystore.h"
-#include "validation.h" // For CheckTransaction
+#include "validation.h"
 #include "policy/policy.h"
 #include "script/script.h"
 #include "script/sign.h"
diff --git a/src/txmempool.cpp b/src/txmempool.cpp
index 0794a3902f..beb2e0482c 100644
--- a/src/txmempool.cpp
+++ b/src/txmempool.cpp
@@ -7,6 +7,7 @@
 
 #include "clientversion.h"
 #include "consensus/consensus.h"
+#include "consensus/tx_verify.h"
 #include "consensus/validation.h"
 #include "validation.h"
 #include "policy/policy.h"
diff --git a/src/validation.cpp b/src/validation.cpp
index 239893dc0b..c9dda96e88 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -11,6 +11,7 @@
 #include "checkqueue.h"
 #include "consensus/consensus.h"
 #include "consensus/merkle.h"
+#include "consensus/tx_verify.h"
 #include "consensus/validation.h"
 #include "fs.h"
 #include "hash.h"
@@ -219,19 +220,6 @@ enum FlushStateMode {
 bool static FlushStateToDisk(CValidationState &state, FlushStateMode mode, int nManualPruneHeight=0);
 void FindFilesToPruneManual(std::set<int>& setFilesToPrune, int nManualPruneHeight);
 
-bool IsFinalTx(const CTransaction &tx, int nBlockHeight, int64_t nBlockTime)
-{
-    if (tx.nLockTime == 0)
-        return true;
-    if ((int64_t)tx.nLockTime < ((int64_t)tx.nLockTime < LOCKTIME_THRESHOLD ? (int64_t)nBlockHeight : nBlockTime))
-        return true;
-    for (const auto& txin : tx.vin) {
-        if (!(txin.nSequence == CTxIn::SEQUENCE_FINAL))
-            return false;
-    }
-    return true;
-}
-
 bool CheckFinalTx(const CTransaction &tx, int flags)
 {
     AssertLockHeld(cs_main);
@@ -264,89 +252,6 @@ bool CheckFinalTx(const CTransaction &tx, int flags)
     return IsFinalTx(tx, nBlockHeight, nBlockTime);
 }
 
-/**
- * Calculates the block height and previous block's median time past at
- * which the transaction will be considered final in the context of BIP 68.
- * Also removes from the vector of input heights any entries which did not
- * correspond to sequence locked inputs as they do not affect the calculation.
- */
-static std::pair<int, int64_t> CalculateSequenceLocks(const CTransaction &tx, int flags, std::vector<int>* prevHeights, const CBlockIndex& block)
-{
-    assert(prevHeights->size() == tx.vin.size());
-
-    // Will be set to the equivalent height- and time-based nLockTime
-    // values that would be necessary to satisfy all relative lock-
-    // time constraints given our view of block chain history.
-    // The semantics of nLockTime are the last invalid height/time, so
-    // use -1 to have the effect of any height or time being valid.
-    int nMinHeight = -1;
-    int64_t nMinTime = -1;
-
-    // tx.nVersion is signed integer so requires cast to unsigned otherwise
-    // we would be doing a signed comparison and half the range of nVersion
-    // wouldn't support BIP 68.
-    bool fEnforceBIP68 = static_cast<uint32_t>(tx.nVersion) >= 2
-                      && flags & LOCKTIME_VERIFY_SEQUENCE;
-
-    // Do not enforce sequence numbers as a relative lock time
-    // unless we have been instructed to
-    if (!fEnforceBIP68) {
-        return std::make_pair(nMinHeight, nMinTime);
-    }
-
-    for (size_t txinIndex = 0; txinIndex < tx.vin.size(); txinIndex++) {
-        const CTxIn& txin = tx.vin[txinIndex];
-
-        // Sequence numbers with the most significant bit set are not
-        // treated as relative lock-times, nor are they given any
-        // consensus-enforced meaning at this point.
-        if (txin.nSequence & CTxIn::SEQUENCE_LOCKTIME_DISABLE_FLAG) {
-            // The height of this input is not relevant for sequence locks
-            (*prevHeights)[txinIndex] = 0;
-            continue;
-        }
-
-        int nCoinHeight = (*prevHeights)[txinIndex];
-
-        if (txin.nSequence & CTxIn::SEQUENCE_LOCKTIME_TYPE_FLAG) {
-            int64_t nCoinTime = block.GetAncestor(std::max(nCoinHeight-1, 0))->GetMedianTimePast();
-            // NOTE: Subtract 1 to maintain nLockTime semantics
-            // BIP 68 relative lock times have the semantics of calculating
-            // the first block or time at which the transaction would be
-            // valid. When calculating the effective block time or height
-            // for the entire transaction, we switch to using the
-            // semantics of nLockTime which is the last invalid block
-            // time or height.  Thus we subtract 1 from the calculated
-            // time or height.
-
-            // Time-based relative lock-times are measured from the
-            // smallest allowed timestamp of the block containing the
-            // txout being spent, which is the median time past of the
-            // block prior.
-            nMinTime = std::max(nMinTime, nCoinTime + (int64_t)((txin.nSequence & CTxIn::SEQUENCE_LOCKTIME_MASK) << CTxIn::SEQUENCE_LOCKTIME_GRANULARITY) - 1);
-        } else {
-            nMinHeight = std::max(nMinHeight, nCoinHeight + (int)(txin.nSequence & CTxIn::SEQUENCE_LOCKTIME_MASK) - 1);
-        }
-    }
-
-    return std::make_pair(nMinHeight, nMinTime);
-}
-
-static bool EvaluateSequenceLocks(const CBlockIndex& block, std::pair<int, int64_t> lockPair)
-{
-    assert(block.pprev);
-    int64_t nBlockTime = block.pprev->GetMedianTimePast();
-    if (lockPair.first >= block.nHeight || lockPair.second >= nBlockTime)
-        return false;
-
-    return true;
-}
-
-bool SequenceLocks(const CTransaction &tx, int flags, std::vector<int>* prevHeights, const CBlockIndex& block)
-{
-    return EvaluateSequenceLocks(block, CalculateSequenceLocks(tx, flags, prevHeights, block));
-}
-
 bool TestLockPointValidity(const LockPoints* lp)
 {
     AssertLockHeld(cs_main);
@@ -436,107 +341,6 @@ bool CheckSequenceLocks(const CTransaction &tx, int flags, LockPoints* lp, bool
 }
 
 
-unsigned int GetLegacySigOpCount(const CTransaction& tx)
-{
-    unsigned int nSigOps = 0;
-    for (const auto& txin : tx.vin)
-    {
-        nSigOps += txin.scriptSig.GetSigOpCount(false);
-    }
-    for (const auto& txout : tx.vout)
-    {
-        nSigOps += txout.scriptPubKey.GetSigOpCount(false);
-    }
-    return nSigOps;
-}
-
-unsigned int GetP2SHSigOpCount(const CTransaction& tx, const CCoinsViewCache& inputs)
-{
-    if (tx.IsCoinBase())
-        return 0;
-
-    unsigned int nSigOps = 0;
-    for (unsigned int i = 0; i < tx.vin.size(); i++)
-    {
-        const CTxOut &prevout = inputs.GetOutputFor(tx.vin[i]);
-        if (prevout.scriptPubKey.IsPayToScriptHash())
-            nSigOps += prevout.scriptPubKey.GetSigOpCount(tx.vin[i].scriptSig);
-    }
-    return nSigOps;
-}
-
-int64_t GetTransactionSigOpCost(const CTransaction& tx, const CCoinsViewCache& inputs, int flags)
-{
-    int64_t nSigOps = GetLegacySigOpCount(tx) * WITNESS_SCALE_FACTOR;
-
-    if (tx.IsCoinBase())
-        return nSigOps;
-
-    if (flags & SCRIPT_VERIFY_P2SH) {
-        nSigOps += GetP2SHSigOpCount(tx, inputs) * WITNESS_SCALE_FACTOR;
-    }
-
-    for (unsigned int i = 0; i < tx.vin.size(); i++)
-    {
-        const CTxOut &prevout = inputs.GetOutputFor(tx.vin[i]);
-        nSigOps += CountWitnessSigOps(tx.vin[i].scriptSig, prevout.scriptPubKey, &tx.vin[i].scriptWitness, flags);
-    }
-    return nSigOps;
-}
-
-
-
-
-
-bool CheckTransaction(const CTransaction& tx, CValidationState &state, bool fCheckDuplicateInputs)
-{
-    // Basic checks that don't depend on any context
-    if (tx.vin.empty())
-        return state.DoS(10, false, REJECT_INVALID, "bad-txns-vin-empty");
-    if (tx.vout.empty())
-        return state.DoS(10, false, REJECT_INVALID, "bad-txns-vout-empty");
-    // Size limits (this doesn't take the witness into account, as that hasn't been checked for malleability)
-    if (::GetSerializeSize(tx, SER_NETWORK, PROTOCOL_VERSION | SERIALIZE_TRANSACTION_NO_WITNESS) > MAX_BLOCK_BASE_SIZE)
-        return state.DoS(100, false, REJECT_INVALID, "bad-txns-oversize");
-
-    // Check for negative or overflow output values
-    CAmount nValueOut = 0;
-    for (const auto& txout : tx.vout)
-    {
-        if (txout.nValue < 0)
-            return state.DoS(100, false, REJECT_INVALID, "bad-txns-vout-negative");
-        if (txout.nValue > MAX_MONEY)
-            return state.DoS(100, false, REJECT_INVALID, "bad-txns-vout-toolarge");
-        nValueOut += txout.nValue;
-        if (!MoneyRange(nValueOut))
-            return state.DoS(100, false, REJECT_INVALID, "bad-txns-txouttotal-toolarge");
-    }
-
-    // Check for duplicate inputs - note that this check is slow so we skip it in CheckBlock
-    if (fCheckDuplicateInputs) {
-        std::set<COutPoint> vInOutPoints;
-        for (const auto& txin : tx.vin)
-        {
-            if (!vInOutPoints.insert(txin.prevout).second)
-                return state.DoS(100, false, REJECT_INVALID, "bad-txns-inputs-duplicate");
-        }
-    }
-
-    if (tx.IsCoinBase())
-    {
-        if (tx.vin[0].scriptSig.size() < 2 || tx.vin[0].scriptSig.size() > 100)
-            return state.DoS(100, false, REJECT_INVALID, "bad-cb-length");
-    }
-    else
-    {
-        for (const auto& txin : tx.vin)
-            if (txin.prevout.IsNull())
-                return state.DoS(10, false, REJECT_INVALID, "bad-txns-prevout-null");
-    }
-
-    return true;
-}
-
 void LimitMempoolSize(CTxMemPool& pool, size_t limit, unsigned long age) {
     int expired = pool.Expire(GetTime() - age);
     if (expired != 0) {
@@ -1343,52 +1147,6 @@ int GetSpendHeight(const CCoinsViewCache& inputs)
     return pindexPrev->nHeight + 1;
 }
 
-namespace Consensus {
-bool CheckTxInputs(const CTransaction& tx, CValidationState& state, const CCoinsViewCache& inputs, int nSpendHeight)
-{
-        // This doesn't trigger the DoS code on purpose; if it did, it would make it easier
-        // for an attacker to attempt to split the network.
-        if (!inputs.HaveInputs(tx))
-            return state.Invalid(false, 0, "", "Inputs unavailable");
-
-        CAmount nValueIn = 0;
-        CAmount nFees = 0;
-        for (unsigned int i = 0; i < tx.vin.size(); i++)
-        {
-            const COutPoint &prevout = tx.vin[i].prevout;
-            const CCoins *coins = inputs.AccessCoins(prevout.hash);
-            assert(coins);
-
-            // If prev is coinbase, check that it's matured
-            if (coins->IsCoinBase()) {
-                if (nSpendHeight - coins->nHeight < COINBASE_MATURITY)
-                    return state.Invalid(false,
-                        REJECT_INVALID, "bad-txns-premature-spend-of-coinbase",
-                        strprintf("tried to spend coinbase at depth %d", nSpendHeight - coins->nHeight));
-            }
-
-            // Check for negative or overflow input values
-            nValueIn += coins->vout[prevout.n].nValue;
-            if (!MoneyRange(coins->vout[prevout.n].nValue) || !MoneyRange(nValueIn))
-                return state.DoS(100, false, REJECT_INVALID, "bad-txns-inputvalues-outofrange");
-
-        }
-
-        if (nValueIn < tx.GetValueOut())
-            return state.DoS(100, false, REJECT_INVALID, "bad-txns-in-belowout", false,
-                strprintf("value in (%s) < value out (%s)", FormatMoney(nValueIn), FormatMoney(tx.GetValueOut())));
-
-        // Tally transaction fees
-        CAmount nTxFee = nValueIn - tx.GetValueOut();
-        if (nTxFee < 0)
-            return state.DoS(100, false, REJECT_INVALID, "bad-txns-fee-negative");
-        nFees += nTxFee;
-        if (!MoneyRange(nFees))
-            return state.DoS(100, false, REJECT_INVALID, "bad-txns-fee-outofrange");
-    return true;
-}
-}// namespace Consensus
-
 bool CheckInputs(const CTransaction& tx, CValidationState &state, const CCoinsViewCache &inputs, bool fScriptChecks, unsigned int flags, bool cacheStore, PrecomputedTransactionData& txdata, std::vector<CScriptCheck> *pvChecks)
 {
     if (!tx.IsCoinBase())
diff --git a/src/validation.h b/src/validation.h
index 4aa10cbb0b..60491818a8 100644
--- a/src/validation.h
+++ b/src/validation.h
@@ -336,30 +336,6 @@ ThresholdState VersionBitsTipState(const Consensus::Params& params, Consensus::D
 /** Get the block height at which the BIP9 deployment switched into the state for the block building on the current tip. */
 int VersionBitsTipStateSinceHeight(const Consensus::Params& params, Consensus::DeploymentPos pos);
 
-/** 
- * Count ECDSA signature operations the old-fashioned (pre-0.6) way
- * @return number of sigops this transaction's outputs will produce when spent
- * @see CTransaction::FetchInputs
- */
-unsigned int GetLegacySigOpCount(const CTransaction& tx);
-
-/**
- * Count ECDSA signature operations in pay-to-script-hash inputs.
- * 
- * @param[in] mapInputs Map of previous transactions that have outputs we're spending
- * @return maximum number of sigops required to validate this transaction's inputs
- * @see CTransaction::FetchInputs
- */
-unsigned int GetP2SHSigOpCount(const CTransaction& tx, const CCoinsViewCache& mapInputs);
-
-/**
- * Compute total signature operation cost of a transaction.
- * @param[in] tx     Transaction for which we are computing the cost
- * @param[in] inputs Map of previous transactions that have outputs we're spending
- * @param[out] flags Script verification flags
- * @return Total signature operation cost of tx
- */
-int64_t GetTransactionSigOpCost(const CTransaction& tx, const CCoinsViewCache& inputs, int flags);
 
 /**
  * Check whether all inputs of this transaction are valid (no double spends, scripts & sigs, amounts)
@@ -374,26 +350,6 @@ void UpdateCoins(const CTransaction& tx, CCoinsViewCache& inputs, int nHeight);
 
 /** Transaction validation functions */
 
-/** Context-independent validity checks */
-bool CheckTransaction(const CTransaction& tx, CValidationState& state, bool fCheckDuplicateInputs=true);
-
-namespace Consensus {
-
-/**
- * Check whether all inputs of this transaction are valid (no double spends and amounts)
- * This does not modify the UTXO set. This does not check scripts and sigs.
- * Preconditions: tx.IsCoinBase() is false.
- */
-bool CheckTxInputs(const CTransaction& tx, CValidationState& state, const CCoinsViewCache& inputs, int nSpendHeight);
-
-} // namespace Consensus
-
-/**
- * Check if transaction is final and can be included in a block with the
- * specified height and time. Consensus critical.
- */
-bool IsFinalTx(const CTransaction &tx, int nBlockHeight, int64_t nBlockTime);
-
 /**
  * Check if transaction will be final in the next block to be created.
  *
@@ -409,12 +365,6 @@ bool CheckFinalTx(const CTransaction &tx, int flags = -1);
 bool TestLockPointValidity(const LockPoints* lp);
 
 /**
- * Check if transaction is final per BIP 68 sequence numbers and can be included in a block.
- * Consensus critical. Takes as input a list of heights at which tx's inputs (in order) confirmed.
- */
-bool SequenceLocks(const CTransaction &tx, int flags, std::vector<int>* prevHeights, const CBlockIndex& block);
-
-/**
  * Check if transaction will be BIP 68 final in the next block to be created.
  *
  * Simulates calling SequenceLocks() with data from the tip of the current active chain.
diff --git a/src/wallet/walletdb.cpp b/src/wallet/walletdb.cpp
index ceff2d36e3..1beeaa042e 100644
--- a/src/wallet/walletdb.cpp
+++ b/src/wallet/walletdb.cpp
@@ -6,9 +6,9 @@
 #include "wallet/walletdb.h"
 
 #include "base58.h"
+#include "consensus/tx_verify.h"
 #include "consensus/validation.h"
 #include "fs.h"
-#include "validation.h" // For CheckTransaction
 #include "protocol.h"
 #include "serialize.h"
 #include "sync.h"