From a90d1521c86fa7bace72322fbc269322c4cfb9c7 Mon Sep 17 00:00:00 2001
From: Andrew Chow <achow101-github@achow101.com>
Date: Mon, 14 Oct 2019 12:22:17 -0400
Subject: [PATCH 1/5] Refactor peg-in witness construction to it's own function

Also changes to Use CVectorWriter instead of casting for peg-in value serialization
---
 src/pegins.cpp           | 42 ++++++++++++++++++++++++++++++++++++++++
 src/pegins.h             |  7 +++++++
 src/wallet/rpcwallet.cpp | 27 +-------------------------
 3 files changed, 50 insertions(+), 26 deletions(-)

diff --git a/src/pegins.cpp b/src/pegins.cpp
index 167d1cd3dd..3dea1bc3ef 100644
--- a/src/pegins.cpp
+++ b/src/pegins.cpp
@@ -496,3 +496,45 @@ std::vector<std::pair<CScript, CScript>> GetValidFedpegScripts(const CBlockIndex
     fedpegscripts.resize(std::min(fedpegscripts.size(), params.total_valid_epochs));
     return fedpegscripts;
 }
+
+template<typename T_tx_ref, typename T_merkle_block>
+CScriptWitness CreatePeginWitnessInner(const CAmount& value, const CAsset& asset, const uint256& genesis_hash, const CScript& claim_script, const T_tx_ref& tx_ref, const T_merkle_block& merkle_block)
+{
+    std::vector<unsigned char> value_bytes;
+    CVectorWriter ss_val(0, 0, value_bytes, 0);
+    try {
+        ss_val << value;
+    } catch (...) {
+        throw std::ios_base::failure("Amount serialization is invalid.");
+    }
+
+    // Strip witness data for proof inclusion since only TXID-covered fields matters
+    CDataStream ss_tx(SER_NETWORK, PROTOCOL_VERSION | SERIALIZE_TRANSACTION_NO_WITNESS);
+    ss_tx << tx_ref;
+    std::vector<unsigned char> tx_data_stripped(ss_tx.begin(), ss_tx.end());
+
+    // Serialize merkle block
+    CDataStream ss_txout_proof(SER_NETWORK, PROTOCOL_VERSION | SERIALIZE_TRANSACTION_NO_WITNESS);
+    ss_txout_proof << merkle_block;
+    std::vector<unsigned char> txout_proof_bytes(ss_txout_proof.begin(), ss_txout_proof.end());
+
+    // Construct pegin proof
+    CScriptWitness pegin_witness;
+    std::vector<std::vector<unsigned char> >& stack = pegin_witness.stack;
+    stack.push_back(value_bytes);
+    stack.push_back(std::vector<unsigned char>(asset.begin(), asset.end()));
+    stack.push_back(std::vector<unsigned char>(genesis_hash.begin(), genesis_hash.end()));
+    stack.push_back(std::vector<unsigned char>(claim_script.begin(), claim_script.end()));
+    stack.push_back(tx_data_stripped);
+    stack.push_back(txout_proof_bytes);
+    return pegin_witness;
+}
+
+CScriptWitness CreatePeginWitness(const CAmount& value, const CAsset& asset, const uint256& genesis_hash, const CScript& claim_script, const CTransactionRef& tx_ref, const CMerkleBlock& merkle_block)
+{
+    return CreatePeginWitnessInner(value, asset, genesis_hash, claim_script, tx_ref, merkle_block);
+}
+CScriptWitness CreatePeginWitness(const CAmount& value, const CAsset& asset, const uint256& genesis_hash, const CScript& claim_script, const Sidechain::Bitcoin::CTransactionRef& tx_ref, const Sidechain::Bitcoin::CMerkleBlock& merkle_block)
+{
+    return CreatePeginWitnessInner(value, asset, genesis_hash, claim_script, tx_ref, merkle_block);
+}
diff --git a/src/pegins.h b/src/pegins.h
index e3e2f80082..86ca57eef4 100644
--- a/src/pegins.h
+++ b/src/pegins.h
@@ -7,7 +7,9 @@
 
 #include <amount.h>
 #include <consensus/params.h>
+#include <merkleblock.h>
 #include <primitives/bitcoin/transaction.h>
+#include <primitives/bitcoin/merkleblock.h>
 #include <primitives/transaction.h>
 #include <script/script.h>
 #include <chain.h>
@@ -38,4 +40,9 @@ bool MatchLiquidWatchman(const CScript& script);
  * scriptPubKey for the script, the second is the witnessScript. */
 std::vector<std::pair<CScript, CScript>> GetValidFedpegScripts(const CBlockIndex* pblockindex, const Consensus::Params& params, bool nextblock_validation);
 
+/** Create the peg-in witness stack */
+CScriptWitness CreatePeginWitness(const CAmount& value, const CAsset& asset, const uint256& genesis_hash, const CScript& claim_script, const CTransactionRef& tx_ref, const CMerkleBlock& merkle_block);
+CScriptWitness CreatePeginWitness(const CAmount& value, const CAsset& asset, const uint256& genesis_hash, const CScript& claim_script, const Sidechain::Bitcoin::CTransactionRef& tx_ref, const Sidechain::Bitcoin::CMerkleBlock& merkle_block);
+
+
 #endif // BITCOIN_PEGINS_H
diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index 69dec5f75f..696d57052c 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -5530,19 +5530,6 @@ static UniValue createrawpegin(const JSONRPCRequest& request, T_tx_ref& txBTCRef
         throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("Amounts to pegin must be explicit and asset must be %s", Params().GetConsensus().parent_pegged_asset.GetHex()));
     }
 
-    CDataStream stream(0, 0);
-    try {
-        stream << value;
-    } catch (...) {
-        throw JSONRPCError(RPC_INVALID_PARAMETER, "Amount serialization is invalid.");
-    }
-    // Need to reinterpret bytes as unsigned chars before adding to witness
-    char* buf = stream.data();
-    unsigned char* membuf = reinterpret_cast<unsigned char*>(buf);
-    std::vector<unsigned char> value_bytes(membuf, membuf + stream.size());
-
-    uint256 genesisBlockHash = Params().ParentGenesisBlockHash();
-
     // Manually construct peg-in transaction, sign it, and send it off.
     // Decrement the output value as much as needed given the total vsize to
     // pay the fees.
@@ -5566,20 +5553,8 @@ static UniValue createrawpegin(const JSONRPCRequest& request, T_tx_ref& txBTCRef
     mtx.vout.push_back(CTxOut(Params().GetConsensus().pegged_asset, value, GetScriptForDestination(wpkhash)));
     mtx.vout.push_back(CTxOut(Params().GetConsensus().pegged_asset, 0, CScript()));
 
-    // Strip witness data for proof inclusion since only TXID-covered fields matters
-    CDataStream ssTxBack(SER_NETWORK, PROTOCOL_VERSION | SERIALIZE_TRANSACTION_NO_WITNESS);
-    ssTxBack << txBTC;
-    std::vector<unsigned char> tx_data_stripped(ssTxBack.begin(), ssTxBack.end());
-
     // Construct pegin proof
-    CScriptWitness pegin_witness;
-    std::vector<std::vector<unsigned char> >& stack = pegin_witness.stack;
-    stack.push_back(value_bytes);
-    stack.push_back(std::vector<unsigned char>(Params().GetConsensus().pegged_asset.begin(), Params().GetConsensus().pegged_asset.end()));
-    stack.push_back(std::vector<unsigned char>(genesisBlockHash.begin(), genesisBlockHash.end()));
-    stack.push_back(std::vector<unsigned char>(witness_script.begin(), witness_script.end()));
-    stack.push_back(tx_data_stripped);
-    stack.push_back(txOutProofData);
+    CScriptWitness pegin_witness = CreatePeginWitness(value, Params().GetConsensus().pegged_asset, Params().ParentGenesisBlockHash(), witness_script, txBTCRef, merkleBlock);
 
     // Peg-in witness isn't valid, even though the block header is(without depth check)
     // We re-check depth before returning with more descriptive result

From 42babb81f097a3426f959035426a137ec76d3d5c Mon Sep 17 00:00:00 2001
From: Andrew Chow <achow101-github@achow101.com>
Date: Mon, 14 Oct 2019 13:37:14 -0400
Subject: [PATCH 2/5] Refactor peg-in input construction into its own function
 in rpc/rawtransaction.cpp

---
 src/rpc/rawtransaction.cpp | 120 +++++++++++++++++++++++++++++++++++++
 src/rpc/rawtransaction.h   |   4 ++
 src/wallet/rpcwallet.cpp   | 108 ++++++---------------------------
 3 files changed, 142 insertions(+), 90 deletions(-)

diff --git a/src/rpc/rawtransaction.cpp b/src/rpc/rawtransaction.cpp
index aa9a3130f4..98e642d981 100644
--- a/src/rpc/rawtransaction.cpp
+++ b/src/rpc/rawtransaction.cpp
@@ -21,6 +21,8 @@
 #include <policy/policy.h>
 #include <policy/rbf.h>
 #include <primitives/transaction.h>
+#include <primitives/bitcoin/merkleblock.h>
+#include <primitives/bitcoin/transaction.h>
 #include <psbt.h>
 #include <rpc/rawtransaction.h>
 #include <rpc/server.h>
@@ -363,6 +365,124 @@ static UniValue verifytxoutproof(const JSONRPCRequest& request)
     return res;
 }
 
+template<typename T_tx>
+unsigned int GetPeginTxnOutputIndex(const T_tx& txn, const CScript& witnessProgram, const std::vector<std::pair<CScript, CScript>>& fedpegscripts)
+{
+    for (const auto & scripts : fedpegscripts) {
+        CScript mainchain_script = GetScriptForWitness(calculate_contract(scripts.second, witnessProgram));
+        if (scripts.first.IsPayToScriptHash()) {
+            mainchain_script = GetScriptForDestination(ScriptHash(mainchain_script));
+        }
+        for (unsigned int nOut = 0; nOut < txn.vout.size(); nOut++)
+            if (txn.vout[nOut].scriptPubKey == mainchain_script) {
+                return nOut;
+            }
+        }
+    return txn.vout.size();
+}
+
+// Modifies an existing transaction input in-place to be a valid peg-in input, and inserts the witness if deemed valid.
+template<typename T_tx_ref, typename T_merkle_block>
+static void CreatePegInInputInner(CMutableTransaction& mtx, uint32_t input_idx, T_tx_ref& txBTCRef, T_merkle_block& merkleBlock, const std::set<CScript>& claim_scripts, const std::vector<unsigned char>& txData, const std::vector<unsigned char>& txOutProofData)
+{
+    if ((mtx.vin.size() > input_idx && !mtx.vin[input_idx].scriptSig.empty()) || (mtx.witness.vtxinwit.size() > input_idx && !mtx.witness.vtxinwit[input_idx].IsNull())) {
+        throw JSONRPCError(RPC_INVALID_PARAMETER, "Attempting to add a peg-in to an input that already has a scriptSig or witness");
+    }
+
+    CDataStream ssTx(txData, SER_NETWORK, PROTOCOL_VERSION);
+    try {
+        ssTx >> txBTCRef;
+    }
+    catch (...) {
+        throw JSONRPCError(RPC_TYPE_ERROR, "The included bitcoinTx is malformed. Are you sure that is the whole string?");
+    }
+
+    CDataStream ssTxOutProof(txOutProofData, SER_NETWORK, PROTOCOL_VERSION | SERIALIZE_TRANSACTION_NO_WITNESS);
+    try {
+        ssTxOutProof >> merkleBlock;
+    }
+    catch (...) {
+        throw JSONRPCError(RPC_TYPE_ERROR, "The included txoutproof is malformed. Are you sure that is the whole string?");
+    }
+
+    if (!ssTxOutProof.empty()) {
+        throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid tx out proof");
+    }
+
+    std::vector<uint256> txHashes;
+    std::vector<unsigned int> txIndices;
+    if (merkleBlock.txn.ExtractMatches(txHashes, txIndices) != merkleBlock.header.hashMerkleRoot)
+        throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid tx out proof");
+
+    if (txHashes.size() != 1 || txHashes[0] != txBTCRef->GetHash())
+        throw JSONRPCError(RPC_INVALID_PARAMETER, "The txoutproof must contain bitcoinTx and only bitcoinTx");
+
+    CScript witness_script;
+    unsigned int nOut = txBTCRef->vout.size();
+    const auto fedpegscripts = GetValidFedpegScripts(chainActive.Tip(), Params().GetConsensus(), true /* nextblock_validation */);
+    for (const CScript& script : claim_scripts) {
+        nOut = GetPeginTxnOutputIndex(*txBTCRef, script, fedpegscripts);
+        if (nOut != txBTCRef->vout.size()) {
+            witness_script = script;
+            break;
+        }
+    }
+    if (nOut == txBTCRef->vout.size()) {
+        if (claim_scripts.size() == 1) {
+            throw JSONRPCError(RPC_INVALID_PARAMETER, "Given claim_script does not match the given Bitcoin transaction.");
+        } else {
+            throw JSONRPCError(RPC_INVALID_PARAMETER, "Failed to find output in bitcoinTx to the mainchain_address from getpeginaddress");
+        }
+    }
+    assert(witness_script != CScript());
+
+    int version = -1;
+    std::vector<unsigned char> witness_program;
+    if (!witness_script.IsWitnessProgram(version, witness_program) || version != 0) {
+        throw JSONRPCError(RPC_INVALID_PARAMETER, "Given or recovered script is not a v0 witness program.");
+    }
+
+    CAmount value = 0;
+    if (!GetAmountFromParentChainPegin(value, *txBTCRef, nOut)) {
+        throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("Amounts to pegin must be explicit and asset must be %s", Params().GetConsensus().parent_pegged_asset.GetHex()));
+    }
+
+    // Add/replace input in mtx
+    if (mtx.vin.size() <= input_idx) {
+        mtx.vin.resize(input_idx + 1);
+    }
+    mtx.vin[input_idx] = CTxIn(COutPoint(txHashes[0], nOut), CScript(), ~(uint32_t)0);
+
+    // Construct pegin proof
+    CScriptWitness pegin_witness = CreatePeginWitness(value, Params().GetConsensus().pegged_asset, Params().ParentGenesisBlockHash(), witness_script, txBTCRef, merkleBlock);
+
+    // Peg-in witness isn't valid, even though the block header is(without depth check)
+    // We re-check depth before returning with more descriptive result
+    std::string err;
+    if (!IsValidPeginWitness(pegin_witness, fedpegscripts, mtx.vin[input_idx].prevout, err, false)) {
+        throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("Constructed peg-in witness is invalid: %s", err));
+    }
+
+    // Put input witness in transaction
+    mtx.vin[input_idx].m_is_pegin = true;
+    CTxInWitness txinwit;
+    txinwit.m_pegin_witness = pegin_witness;
+
+    if (mtx.witness.vtxinwit.size() <= input_idx) {
+        mtx.witness.vtxinwit.resize(input_idx + 1);
+    }
+    mtx.witness.vtxinwit[input_idx] = txinwit;
+}
+
+void CreatePegInInput(CMutableTransaction& mtx, uint32_t input_idx, CTransactionRef& tx_btc, CMerkleBlock& merkle_block, const std::set<CScript>& claim_scripts, const std::vector<unsigned char>& txData, const std::vector<unsigned char>& txOutProofData)
+{
+    CreatePegInInputInner(mtx, input_idx, tx_btc, merkle_block, claim_scripts, txData, txOutProofData);
+}
+void CreatePegInInput(CMutableTransaction& mtx, uint32_t input_idx, Sidechain::Bitcoin::CTransactionRef& tx_btc, Sidechain::Bitcoin::CMerkleBlock& merkle_block, const std::set<CScript>& claim_scripts, const std::vector<unsigned char>& txData, const std::vector<unsigned char>& txOutProofData)
+{
+    CreatePegInInputInner(mtx, input_idx, tx_btc, merkle_block, claim_scripts, txData, txOutProofData);
+}
+
 CMutableTransaction ConstructTransaction(const UniValue& inputs_in, const UniValue& outputs_in, const UniValue& locktime, const UniValue& rbf, const UniValue& assets_in, std::vector<CPubKey>* output_pubkeys_out)
 {
     if (inputs_in.isNull() || outputs_in.isNull())
diff --git a/src/rpc/rawtransaction.h b/src/rpc/rawtransaction.h
index 56eec70cef..42b5e8ba9b 100644
--- a/src/rpc/rawtransaction.h
+++ b/src/rpc/rawtransaction.h
@@ -21,4 +21,8 @@ UniValue SignTransaction(interfaces::Chain& chain, CMutableTransaction& mtx, con
     Assets output pubkeys in nonces will be used. */
 CMutableTransaction ConstructTransaction(const UniValue& inputs_in, const UniValue& outputs_in, const UniValue& locktime, const UniValue& rbf, const UniValue& assets_in, std::vector<CPubKey>* output_pubkeys_out = nullptr);
 
+/** Create a peg-in input */
+void CreatePegInInput(CMutableTransaction& mtx, uint32_t input_idx, CTransactionRef& tx_btc, CMerkleBlock& merkle_block, const std::set<CScript>& claim_scripts, const std::vector<unsigned char>& txData, const std::vector<unsigned char>& txOutProofData);
+void CreatePegInInput(CMutableTransaction& mtx, uint32_t input_idx, Sidechain::Bitcoin::CTransactionRef& tx_btc, Sidechain::Bitcoin::CMerkleBlock& merkle_block, const std::set<CScript>& claim_scripts, const std::vector<unsigned char>& txData, const std::vector<unsigned char>& txOutProofData);
+
 #endif // BITCOIN_RPC_RAWTRANSACTION_H
diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index 696d57052c..1abee184c8 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -5404,22 +5404,6 @@ UniValue sendtomainchain(const JSONRPCRequest& request)
 extern UniValue signrawtransaction(const JSONRPCRequest& request);
 extern UniValue sendrawtransaction(const JSONRPCRequest& request);
 
-template<typename T_tx>
-unsigned int GetPeginTxnOutputIndex(const T_tx& txn, const CScript& witnessProgram, const std::vector<std::pair<CScript, CScript>>& fedpegscripts)
-{
-    for (const auto & scripts : fedpegscripts) {
-        CScript mainchain_script = GetScriptForWitness(calculate_contract(scripts.second, witnessProgram));
-        if (scripts.first.IsPayToScriptHash()) {
-            mainchain_script = GetScriptForDestination(ScriptHash(mainchain_script));
-        }
-        for (unsigned int nOut = 0; nOut < txn.vout.size(); nOut++)
-            if (txn.vout[nOut].scriptPubKey == mainchain_script) {
-                return nOut;
-            }
-        }
-    return txn.vout.size();
-}
-
 template<typename T_tx_ref, typename T_tx, typename T_merkle_block>
 static UniValue createrawpegin(const JSONRPCRequest& request, T_tx_ref& txBTCRef, T_tx& tx_aux, T_merkle_block& merkleBlock)
 {
@@ -5457,39 +5441,9 @@ static UniValue createrawpegin(const JSONRPCRequest& request, T_tx_ref& txBTCRef
     }
 
     std::vector<unsigned char> txData = ParseHex(request.params[0].get_str());
-    CDataStream ssTx(txData, SER_NETWORK, PROTOCOL_VERSION);
-    try {
-        ssTx >> txBTCRef;
-    }
-    catch (...) {
-        throw JSONRPCError(RPC_TYPE_ERROR, "The included bitcoinTx is malformed. Are you sure that is the whole string?");
-    }
-    T_tx txBTC(*txBTCRef);
-
     std::vector<unsigned char> txOutProofData = ParseHex(request.params[1].get_str());
-    CDataStream ssTxOutProof(txOutProofData, SER_NETWORK, PROTOCOL_VERSION | SERIALIZE_TRANSACTION_NO_WITNESS);
-    try {
-        ssTxOutProof >> merkleBlock;
-    }
-    catch (...) {
-        throw JSONRPCError(RPC_TYPE_ERROR, "The included txoutproof is malformed. Are you sure that is the whole string?");
-    }
 
-    if (!ssTxOutProof.empty()) {
-        throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid tx out proof");
-    }
-
-    std::vector<uint256> txHashes;
-    std::vector<unsigned int> txIndices;
-    if (merkleBlock.txn.ExtractMatches(txHashes, txIndices) != merkleBlock.header.hashMerkleRoot)
-        throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid tx out proof");
-
-    if (txHashes.size() != 1 || txHashes[0] != txBTC.GetHash())
-        throw JSONRPCError(RPC_INVALID_PARAMETER, "The txoutproof must contain bitcoinTx and only bitcoinTx");
-
-    CScript witness_script;
-    unsigned int nOut = txBTC.vout.size();
-    const auto fedpegscripts = GetValidFedpegScripts(chainActive.Tip(), Params().GetConsensus(), true /* nextblock_validation */);
+    std::set<CScript> claim_scripts;
     if (request.params.size() > 2) {
         const std::string claim_script = request.params[2].get_str();
         if (!IsHex(claim_script)) {
@@ -5497,38 +5451,22 @@ static UniValue createrawpegin(const JSONRPCRequest& request, T_tx_ref& txBTCRef
         }
         // If given manually, no need for it to be a witness script
         std::vector<unsigned char> witnessBytes(ParseHex(claim_script));
-        witness_script = CScript(witnessBytes.begin(), witnessBytes.end());
-        nOut = GetPeginTxnOutputIndex(txBTC, witness_script, fedpegscripts);
-        if (nOut == txBTC.vout.size()) {
-            throw JSONRPCError(RPC_INVALID_PARAMETER, "Given claim_script does not match the given Bitcoin transaction.");
-        }
+        CScript witness_script(witnessBytes.begin(), witnessBytes.end());
+        claim_scripts.insert(std::move(witness_script));
     }
     else {
         // Look for known wpkh address in wallet
         for (std::map<CTxDestination, CAddressBookData>::const_iterator iter = pwallet->mapAddressBook.begin(); iter != pwallet->mapAddressBook.end(); ++iter) {
             CScript dest_script = GetScriptForDestination(iter->first);
-            nOut = GetPeginTxnOutputIndex(txBTC, dest_script, fedpegscripts);
-            if (nOut != txBTC.vout.size()) {
-                witness_script = dest_script;
-                break;
-            }
+            claim_scripts.insert(std::move(dest_script));
         }
     }
-    if (nOut == txBTC.vout.size()) {
-        throw JSONRPCError(RPC_INVALID_PARAMETER, "Failed to find output in bitcoinTx to the mainchain_address from getpeginaddress");
-    }
-    assert(witness_script != CScript());
 
-    int version = -1;
-    std::vector<unsigned char> witness_program;
-    if (!witness_script.IsWitnessProgram(version, witness_program) || version != 0) {
-        throw JSONRPCError(RPC_INVALID_PARAMETER, "Given or recovered script is not a v0 witness program.");
-    }
+    // Make the tx
+    CMutableTransaction mtx;
 
-    CAmount value = 0;
-    if (!GetAmountFromParentChainPegin(value, txBTC, nOut)) {
-        throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("Amounts to pegin must be explicit and asset must be %s", Params().GetConsensus().parent_pegged_asset.GetHex()));
-    }
+    // Construct pegin input
+    CreatePegInInput(mtx, 0, txBTCRef, merkleBlock, claim_scripts, txData, txOutProofData);
 
     // Manually construct peg-in transaction, sign it, and send it off.
     // Decrement the output value as much as needed given the total vsize to
@@ -5545,28 +5483,15 @@ static UniValue createrawpegin(const JSONRPCRequest& request, T_tx_ref& txBTCRef
 
     pwallet->SetAddressBook(wpkhash, "", "receive");
 
-    // One peg-in input, one wallet output and one fee output
-    CMutableTransaction mtx;
-    mtx.vin.push_back(CTxIn(COutPoint(txHashes[0], nOut), CScript(), ~(uint32_t)0));
-    // mark as peg-in input
-    mtx.vin[0].m_is_pegin = true;
-    mtx.vout.push_back(CTxOut(Params().GetConsensus().pegged_asset, value, GetScriptForDestination(wpkhash)));
-    mtx.vout.push_back(CTxOut(Params().GetConsensus().pegged_asset, 0, CScript()));
-
-    // Construct pegin proof
-    CScriptWitness pegin_witness = CreatePeginWitness(value, Params().GetConsensus().pegged_asset, Params().ParentGenesisBlockHash(), witness_script, txBTCRef, merkleBlock);
-
-    // Peg-in witness isn't valid, even though the block header is(without depth check)
-    // We re-check depth before returning with more descriptive result
-    std::string err;
-    if (!IsValidPeginWitness(pegin_witness, fedpegscripts, mtx.vin[0].prevout, err, false)) {
-        throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("Constructed peg-in witness is invalid: %s", err));
+    // Get value for output
+    CAmount value = 0;
+    if (!GetAmountFromParentChainPegin(value, *txBTCRef, mtx.vin[0].prevout.n)) {
+        throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("Amounts to pegin must be explicit and asset must be %s", Params().GetConsensus().parent_pegged_asset.GetHex()));
     }
 
-    // Put input witness in transaction
-    CTxInWitness txinwit;
-    txinwit.m_pegin_witness = pegin_witness;
-    mtx.witness.vtxinwit.push_back(txinwit);
+    // one wallet output and one fee output
+    mtx.vout.push_back(CTxOut(Params().GetConsensus().pegged_asset, value, GetScriptForDestination(wpkhash)));
+    mtx.vout.push_back(CTxOut(Params().GetConsensus().pegged_asset, 0, CScript()));
 
     // Estimate fee for transaction, decrement fee output(including witness data)
     unsigned int nBytes = GetVirtualTransactionSize(CTransaction(mtx)) +
@@ -5586,6 +5511,9 @@ static UniValue createrawpegin(const JSONRPCRequest& request, T_tx_ref& txBTCRef
     // Additional block lee-way to avoid bitcoin block races
     if (gArgs.GetBoolArg("-validatepegin", Params().GetConsensus().has_parent_chain)) {
         unsigned int required_depth = Params().GetConsensus().pegin_min_depth + 2;
+        std::vector<uint256> txHashes;
+        std::vector<unsigned int> txIndices;
+        merkleBlock.txn.ExtractMatches(txHashes, txIndices);
         if (txIndices[0] == 0) {
             required_depth = std::max(required_depth, (unsigned int)COINBASE_MATURITY+2);
         }

From cefe40767d8453eafe45c422b221360ce631d265 Mon Sep 17 00:00:00 2001
From: Andrew Chow <achow101-github@achow101.com>
Date: Mon, 14 Oct 2019 14:47:57 -0400
Subject: [PATCH 3/5] Allow specifying peg-in info in raw transaction RPC
 inputs

---
 src/rpc/rawtransaction.cpp | 45 +++++++++++++++++++++++++++++++++++---
 src/rpc/rawtransaction.h   |  2 +-
 src/wallet/rpcwallet.cpp   |  2 +-
 3 files changed, 44 insertions(+), 5 deletions(-)

diff --git a/src/rpc/rawtransaction.cpp b/src/rpc/rawtransaction.cpp
index 98e642d981..ba3c4ca650 100644
--- a/src/rpc/rawtransaction.cpp
+++ b/src/rpc/rawtransaction.cpp
@@ -4,6 +4,7 @@
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include <asset.h>
+#include <block_proof.h>
 #include <chain.h>
 #include <coins.h>
 #include <compat/byteswap.h>
@@ -483,7 +484,7 @@ void CreatePegInInput(CMutableTransaction& mtx, uint32_t input_idx, Sidechain::B
     CreatePegInInputInner(mtx, input_idx, tx_btc, merkle_block, claim_scripts, txData, txOutProofData);
 }
 
-CMutableTransaction ConstructTransaction(const UniValue& inputs_in, const UniValue& outputs_in, const UniValue& locktime, const UniValue& rbf, const UniValue& assets_in, std::vector<CPubKey>* output_pubkeys_out)
+CMutableTransaction ConstructTransaction(const UniValue& inputs_in, const UniValue& outputs_in, const UniValue& locktime, const UniValue& rbf, const UniValue& assets_in, std::vector<CPubKey>* output_pubkeys_out, bool allow_peg_in)
 {
     if (inputs_in.isNull() || outputs_in.isNull())
         throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid parameter, arguments 1 and 2 must be non-null");
@@ -542,8 +543,43 @@ CMutableTransaction ConstructTransaction(const UniValue& inputs_in, const UniVal
         }
 
         CTxIn in(COutPoint(txid, nOutput), CScript(), nSequence);
-
         rawTx.vin.push_back(in);
+
+        // Get the pegin stuff if it's there
+        const UniValue& pegin_tx = find_value(o, "pegin_bitcoin_tx");
+        const UniValue& pegin_tx_proof = find_value(o, "pegin_txout_proof");
+        const UniValue& pegin_script = find_value(o, "pegin_claim_script");
+        if (!pegin_tx.isNull() && !pegin_tx_proof.isNull() && !pegin_script.isNull() && allow_peg_in) {
+            if (!IsHex(pegin_script.get_str())) {
+                throw JSONRPCError(RPC_INVALID_PARAMETER, "Given claim_script is not hex.");
+            }
+            // If given manually, no need for it to be a witness script
+            std::vector<unsigned char> claim_script_bytes(ParseHex(pegin_script.get_str()));
+            CScript claim_script(claim_script_bytes.begin(), claim_script_bytes.end());
+            std::set<CScript> claim_scripts;
+            claim_scripts.insert(std::move(claim_script));
+            if (Params().GetConsensus().ParentChainHasPow()) {
+                Sidechain::Bitcoin::CTransactionRef tx_btc;
+                Sidechain::Bitcoin::CMerkleBlock merkle_block;
+                CreatePegInInput(rawTx, idx, tx_btc, merkle_block, claim_scripts, ParseHex(pegin_tx.get_str()), ParseHex(pegin_tx_proof.get_str()));
+                if (!CheckParentProofOfWork(merkle_block.header.GetHash(), merkle_block.header.nBits, Params().GetConsensus())) {
+                    throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid tx out proof");
+                }
+            } else {
+                CTransactionRef tx_btc;
+                CMerkleBlock merkle_block;
+                CreatePegInInput(rawTx, idx, tx_btc, merkle_block, claim_scripts, ParseHex(pegin_tx.get_str()), ParseHex(pegin_tx_proof.get_str()));
+                if (!CheckProofSignedParent(merkle_block.header, Params().GetConsensus())) {
+                    throw JSONRPCError(RPC_INVALID_PARAMETER, "Invalid tx out proof");
+                }
+            }
+        } else if (!pegin_tx.isNull() || !pegin_tx_proof.isNull() || !pegin_script.isNull()) {
+            if (allow_peg_in) {
+                throw JSONRPCError(RPC_INVALID_PARAMETER, "Some but not all pegin_ arguments provided");
+            } else {
+                throw JSONRPCError(RPC_INVALID_PARAMETER, "pegin_ arguments provided but this command does not support peg-ins");
+            }
+        }
     }
 
     if (!outputs_is_obj) {
@@ -678,6 +714,9 @@ static UniValue createrawtransaction(const JSONRPCRequest& request)
                                     {"txid", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "The transaction id"},
                                     {"vout", RPCArg::Type::NUM, RPCArg::Optional::NO, "The output number"},
                                     {"sequence", RPCArg::Type::NUM, /* default */ "depends on the value of the 'replaceable' and 'locktime' arguments", "The sequence number"},
+                                    {"pegin_bitcoin_tx", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "The raw bitcoin transaction (in hex) depositing bitcoin to the mainchain_address generated by getpeginaddress"},
+                                    {"pegin_txout_proof", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "A rawtxoutproof (in hex) generated by the mainchain daemon's `gettxoutproof` containing a proof of only bitcoin_tx"},
+                                    {"pegin_claim_script", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "The claim script generated by getpeginaddress."},
                                 },
                                 },
                         },
@@ -2072,7 +2111,7 @@ UniValue createpsbt(const JSONRPCRequest& request)
     );
 
     std::vector<CPubKey> output_pubkeys;
-    CMutableTransaction rawTx = ConstructTransaction(request.params[0], request.params[1], request.params[2], request.params[3], request.params[4], &output_pubkeys);
+    CMutableTransaction rawTx = ConstructTransaction(request.params[0], request.params[1], request.params[2], request.params[3], request.params[4], &output_pubkeys, false /* allow_peg_in */);
 
     // Make a blank psbt
     PartiallySignedTransaction psbtx(rawTx);
diff --git a/src/rpc/rawtransaction.h b/src/rpc/rawtransaction.h
index 42b5e8ba9b..42784aeb46 100644
--- a/src/rpc/rawtransaction.h
+++ b/src/rpc/rawtransaction.h
@@ -19,7 +19,7 @@ UniValue SignTransaction(interfaces::Chain& chain, CMutableTransaction& mtx, con
 /** Create a transaction from univalue parameters. If (and only if)
     output_pubkeys_out is null, the "nonce hack" of storing Confidential
     Assets output pubkeys in nonces will be used. */
-CMutableTransaction ConstructTransaction(const UniValue& inputs_in, const UniValue& outputs_in, const UniValue& locktime, const UniValue& rbf, const UniValue& assets_in, std::vector<CPubKey>* output_pubkeys_out = nullptr);
+CMutableTransaction ConstructTransaction(const UniValue& inputs_in, const UniValue& outputs_in, const UniValue& locktime, const UniValue& rbf, const UniValue& assets_in, std::vector<CPubKey>* output_pubkeys_out = nullptr, bool allow_peg_in = true);
 
 /** Create a peg-in input */
 void CreatePegInInput(CMutableTransaction& mtx, uint32_t input_idx, CTransactionRef& tx_btc, CMerkleBlock& merkle_block, const std::set<CScript>& claim_scripts, const std::vector<unsigned char>& txData, const std::vector<unsigned char>& txOutProofData);
diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index 1abee184c8..5d1398027d 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -4672,7 +4672,7 @@ UniValue walletcreatefundedpsbt(const JSONRPCRequest& request)
     // It's hard to control the behavior of FundTransaction, so we will wait
     //   until after it's done, then extract the blinding keys from the output
     //   nonces.
-    CMutableTransaction rawTx = ConstructTransaction(request.params[0], request.params[1], request.params[2], request.params[3]["replaceable"], NullUniValue /* CA: assets_in */);
+    CMutableTransaction rawTx = ConstructTransaction(request.params[0], request.params[1], request.params[2], request.params[3]["replaceable"], NullUniValue /* CA: assets_in */, nullptr /* output_pubkeys_out */, false /* allow_peg_in */);
     FundTransaction(pwallet, rawTx, fee, change_position, request.params[3]);
 
     // Make a blank psbt

From ac6f052a6d4737b05c808efa1e6ece6236fbb885 Mon Sep 17 00:00:00 2001
From: Andrew Chow <achow101-github@achow101.com>
Date: Tue, 15 Oct 2019 15:06:19 -0400
Subject: [PATCH 4/5] Have find_vout_for_address only get non-confidential
 address when using elements chain

---
 test/functional/test_framework/util.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/test/functional/test_framework/util.py b/test/functional/test_framework/util.py
index e5f970900a..6282cf1e76 100644
--- a/test/functional/test_framework/util.py
+++ b/test/functional/test_framework/util.py
@@ -598,7 +598,9 @@ def find_vout_for_address(node, txid, addr):
     given address. Raises runtime error exception if not found.
     """
     tx = node.getrawtransaction(txid, True)
-    unblind_addr = node.validateaddress(addr)["unconfidential"]
+    unblind_addr = addr
+    if node.getblockchaininfo()['chain'] == 'elementsregtest':
+        unblind_addr = node.validateaddress(addr)["unconfidential"]
     for i in range(len(tx["vout"])):
         if tx["vout"][i]["scriptPubKey"]["type"] == "fee":
             continue

From 5a4d61169b5c8605c13353b4d3bc5c6c73e58743 Mon Sep 17 00:00:00 2001
From: Andrew Chow <achow101-github@achow101.com>
Date: Tue, 15 Oct 2019 15:22:17 -0400
Subject: [PATCH 5/5] Test raw transaction peg-in

---
 test/functional/feature_fedpeg.py | 14 ++++++++++++++
 test/functional/rpc_psbt.py       |  8 ++++++++
 2 files changed, 22 insertions(+)

diff --git a/test/functional/feature_fedpeg.py b/test/functional/feature_fedpeg.py
index 55d5495135..19e9f2b598 100755
--- a/test/functional/feature_fedpeg.py
+++ b/test/functional/feature_fedpeg.py
@@ -15,6 +15,7 @@
     assert_equal,
     bytes_to_hex_str,
     hex_str_to_bytes,
+    find_vout_for_address
 )
 from test_framework import util
 from test_framework.messages import (
@@ -218,6 +219,7 @@ def run_test(self):
         addr = addrs["mainchain_address"]
         assert_equal(sidechain.decodescript(addrs["claim_script"])["type"], "witness_v0_keyhash")
         txid1 = parent.sendtoaddress(addr, 24)
+        vout = find_vout_for_address(parent, txid1, addr)
         # 10+2 confirms required to get into mempool and confirm
         assert_equal(sidechain.getsidechaininfo()["pegin_confirmation_depth"], 10)
         parent.generate(1)
@@ -278,6 +280,18 @@ def run_test(self):
         raw_pegin = sidechain.createrawpegin(raw, proof)['hex']
         signed_pegin = sidechain.signrawtransactionwithwallet(raw_pegin)
 
+        # Find the address that the peg-in used
+        outputs = []
+        for pegin_vout in sidechain.decoderawtransaction(raw_pegin)['vout']:
+            if pegin_vout['scriptPubKey']['type'] == 'witness_v0_keyhash':
+                outputs.append({pegin_vout['scriptPubKey']['addresses'][0]: pegin_vout['value']})
+            elif pegin_vout['scriptPubKey']['type'] == 'fee':
+                outputs.append({"fee": pegin_vout['value']})
+
+        # Check the createrawtransaction makes the same unsigned peg-in transaction
+        raw_pegin2 = sidechain.createrawtransaction([{"txid":txid1, "vout": vout, "pegin_bitcoin_tx": raw, "pegin_txout_proof": proof, "pegin_claim_script": addrs["claim_script"]}], outputs)
+        assert_equal(raw_pegin, raw_pegin2)
+
         sample_pegin_struct = FromHex(CTransaction(), signed_pegin["hex"])
         # Round-trip peg-in transaction using python serialization
         assert_equal(signed_pegin["hex"], sample_pegin_struct.serialize().hex())
diff --git a/test/functional/rpc_psbt.py b/test/functional/rpc_psbt.py
index 7a0f9f6d0f..25ea4d9f52 100755
--- a/test/functional/rpc_psbt.py
+++ b/test/functional/rpc_psbt.py
@@ -524,6 +524,14 @@ def run_test(self):
         # Some Confidential-Assets-specific tests
         self.run_ca_tests()
 
+        # Check that peg-ins are disallowed
+        assert_raises_rpc_error(-8, 'pegin_ arguments provided but this command does not support peg-ins', self.nodes[0].createpsbt, [{"txid": "0000000000000000000000000000000000000000000000000000000000000000", "vout": 0, "pegin_bitcoin_tx": "00"}], [{self.nodes[0].getnewaddress(): 1}])
+        assert_raises_rpc_error(-8, 'pegin_ arguments provided but this command does not support peg-ins', self.nodes[0].createpsbt, [{"txid": "0000000000000000000000000000000000000000000000000000000000000000", "vout": 0, "pegin_txout_proof": "00"}], [{self.nodes[0].getnewaddress(): 1}])
+        assert_raises_rpc_error(-8, 'pegin_ arguments provided but this command does not support peg-ins', self.nodes[0].createpsbt, [{"txid": "0000000000000000000000000000000000000000000000000000000000000000", "vout": 0, "pegin_claim_script": "00"}], [{self.nodes[0].getnewaddress(): 1}])
+        assert_raises_rpc_error(-8, 'pegin_ arguments provided but this command does not support peg-ins', self.nodes[0].walletcreatefundedpsbt, [{"txid": "0000000000000000000000000000000000000000000000000000000000000000", "vout": 0, "pegin_bitcoin_tx": "00"}], [{self.nodes[0].getnewaddress(): 1}])
+        assert_raises_rpc_error(-8, 'pegin_ arguments provided but this command does not support peg-ins', self.nodes[0].walletcreatefundedpsbt, [{"txid": "0000000000000000000000000000000000000000000000000000000000000000", "vout": 0, "pegin_txout_proof": "00"}], [{self.nodes[0].getnewaddress(): 1}])
+        assert_raises_rpc_error(-8, 'pegin_ arguments provided but this command does not support peg-ins', self.nodes[0].walletcreatefundedpsbt, [{"txid": "0000000000000000000000000000000000000000000000000000000000000000", "vout": 0, "pegin_claim_script": "00"}], [{self.nodes[0].getnewaddress(): 1}])
+
         # Tests added in the 0.18 rebase don't pass on Elements yet.
 
         """