From a9f589b9ecce8e0bb3f62dc2f03aea064469f147 Mon Sep 17 00:00:00 2001
From: Steven Roose <steven@stevenroose.org>
Date: Wed, 12 Jun 2019 22:25:09 +0100
Subject: [PATCH] Add support for blinding pegin transactions

Both via blindrawtransaction and rawblindrawtransaction.
---
 src/blind.cpp              |  4 ++--
 src/rpc/rawtransaction.cpp | 14 ++++++++++++++
 src/wallet/rpcwallet.cpp   | 14 ++++++++++++++
 3 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/src/blind.cpp b/src/blind.cpp
index 5f465f1e1d..e723ecbb27 100644
--- a/src/blind.cpp
+++ b/src/blind.cpp
@@ -530,7 +530,7 @@ int BlindTransaction(std::vector<uint256 >& input_value_blinding_factors, const
                 // abort and not blind and the math adds up.
                 // Count as success(to signal caller that nothing wrong) and return early
                 if (memcmp(diff_zero, &blind[num_blind_attempts-1][0], 32) == 0) {
-                   return ++num_blinded;
+                    return ++num_blinded;
                 }
             }
 
@@ -539,7 +539,7 @@ int BlindTransaction(std::vector<uint256 >& input_value_blinding_factors, const
             out_val_blind_factors[nOut] = uint256(std::vector<unsigned char>(value_blindptrs[value_blindptrs.size()-1], value_blindptrs[value_blindptrs.size()-1]+32));
             out_asset_blind_factors[nOut] = uint256(std::vector<unsigned char>(asset_blindptrs[asset_blindptrs.size()-1], asset_blindptrs[asset_blindptrs.size()-1]+32));
 
-            //Blind the asset ID
+            // Blind the asset ID
             BlindAsset(conf_asset, asset_gen, asset, asset_blindptrs.back());
 
             // Create value commitment
diff --git a/src/rpc/rawtransaction.cpp b/src/rpc/rawtransaction.cpp
index 9003385d2c..684217eca4 100644
--- a/src/rpc/rawtransaction.cpp
+++ b/src/rpc/rawtransaction.cpp
@@ -2248,6 +2248,20 @@ UniValue rawblindrawtransaction(const JSONRPCRequest& request)
     std::vector<CAsset> output_assets;
     std::vector<CPubKey> output_pubkeys;
     for (size_t nIn = 0; nIn < tx.vin.size(); nIn++) {
+        // Special handling for pegin inputs: no blinds and explicit amount/asset.
+        if (tx.vin[nIn].m_is_pegin) {
+            std::string err;
+            if (tx.witness.vtxinwit.size() != tx.vin.size() || !IsValidPeginWitness(tx.witness.vtxinwit[nIn].m_pegin_witness, tx.vin[nIn].prevout, err, false)) {
+                throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("Transaction contains invalid peg-in input: %s", err));
+            }
+            CTxOut pegin_output = GetPeginOutputFromWitness(tx.witness.vtxinwit[nIn].m_pegin_witness);
+            input_blinds.push_back(uint256());
+            input_asset_blinds.push_back(uint256());
+            input_assets.push_back(pegin_output.nAsset.GetAsset());
+            input_amounts.push_back(pegin_output.nValue.GetAmount());
+            continue;
+        }
+
         if (!inputBlinds[nIn].isStr())
             throw JSONRPCError(RPC_INVALID_PARAMETER, "input blinds must be an array of hex strings");
         if (!inputAssetBlinds[nIn].isStr())
diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index 16abc05e40..16c9028a09 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -5778,6 +5778,20 @@ UniValue blindrawtransaction(const JSONRPCRequest& request)
     for (size_t nIn = 0; nIn < tx.vin.size(); ++nIn) {
         COutPoint prevout = tx.vin[nIn].prevout;
 
+        // Special handling for pegin inputs: no blinds and explicit amount/asset.
+        if (tx.vin[nIn].m_is_pegin) {
+            std::string err;
+            if (tx.witness.vtxinwit.size() != tx.vin.size() || !IsValidPeginWitness(tx.witness.vtxinwit[nIn].m_pegin_witness, prevout, err, false)) {
+                throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("Transaction contains invalid peg-in input: %s", err));
+            }
+            CTxOut pegin_output = GetPeginOutputFromWitness(tx.witness.vtxinwit[nIn].m_pegin_witness);
+            input_blinds.push_back(uint256());
+            input_asset_blinds.push_back(uint256());
+            input_assets.push_back(pegin_output.nAsset.GetAsset());
+            input_amounts.push_back(pegin_output.nValue.GetAmount());
+            continue;
+        }
+
         std::map<uint256, CWalletTx>::iterator it = pwallet->mapWallet.find(prevout.hash);
         if (it == pwallet->mapWallet.end() || pwallet->IsMine(tx.vin[nIn]) == ISMINE_NO) {
             // For inputs we don't own, input assetcommitments for the surjection must be supplied.