From 990b084f11c038367035ad520482174900cdd29c Mon Sep 17 00:00:00 2001
From: Ava Chow <github@achow101.com>
Date: Mon, 22 Jul 2024 17:14:07 -0400
Subject: [PATCH] Have PSBTInput and PSBTOutput know the PSBT's version

---
 src/psbt.cpp                  |  4 ++--
 src/psbt.h                    | 30 +++++++++++++++++++++++++-----
 src/rpc/rawtransaction.cpp    |  8 ++++----
 src/test/fuzz/deserialize.cpp |  4 ++--
 4 files changed, 33 insertions(+), 13 deletions(-)

diff --git a/src/psbt.cpp b/src/psbt.cpp
index 3086ae7775e..416eae11d1f 100644
--- a/src/psbt.cpp
+++ b/src/psbt.cpp
@@ -15,8 +15,8 @@ using common::PSBTError;
 
 PartiallySignedTransaction::PartiallySignedTransaction(const CMutableTransaction& tx) : tx(tx)
 {
-    inputs.resize(tx.vin.size());
-    outputs.resize(tx.vout.size());
+    inputs.resize(tx.vin.size(), PSBTInput(GetVersion()));
+    outputs.resize(tx.vout.size(), PSBTOutput(GetVersion()));
 }
 
 bool PartiallySignedTransaction::IsNull() const
diff --git a/src/psbt.h b/src/psbt.h
index f6bf144ab8d..4272cd3a807 100644
--- a/src/psbt.h
+++ b/src/psbt.h
@@ -263,6 +263,9 @@ static inline void ExpectedKeySize(const std::string& key_name, const std::vecto
 /** A structure for PSBTs which contain per-input information */
 class PSBTInput
 {
+private:
+    uint32_t m_psbt_version;
+
 public:
     CTransactionRef non_witness_utxo;
     CTxOut witness_utxo;
@@ -300,7 +303,12 @@ public:
     void FillSignatureData(SignatureData& sigdata) const;
     void FromSignatureData(const SignatureData& sigdata);
     void Merge(const PSBTInput& input);
-    PSBTInput() = default;
+    uint32_t GetVersion() const { return m_psbt_version; }
+    explicit PSBTInput(uint32_t psbt_version)
+        : m_psbt_version(psbt_version)
+    {
+        assert(m_psbt_version == 0);
+    }
 
     template <typename Stream>
     inline void Serialize(Stream& s) const {
@@ -794,6 +802,9 @@ public:
 /** A structure for PSBTs which contains per output information */
 class PSBTOutput
 {
+private:
+    uint32_t m_psbt_version;
+
 public:
     CScript redeem_script;
     CScript witness_script;
@@ -809,7 +820,12 @@ public:
     void FillSignatureData(SignatureData& sigdata) const;
     void FromSignatureData(const SignatureData& sigdata);
     void Merge(const PSBTOutput& output);
-    PSBTOutput() = default;
+    uint32_t GetVersion() const { return m_psbt_version; }
+    explicit PSBTOutput(uint32_t psbt_version)
+        : m_psbt_version(psbt_version)
+    {
+        assert(m_psbt_version == 0);
+    }
 
     template <typename Stream>
     inline void Serialize(Stream& s) const {
@@ -1031,6 +1047,9 @@ public:
 /** A version of CTransaction with the PSBT format*/
 class PartiallySignedTransaction
 {
+private:
+    std::optional<uint32_t> m_version;
+
 public:
     std::optional<CMutableTransaction> tx;
     // We use a vector of CExtPubKey in the event that there happens to be the same KeyOriginInfos for different CExtPubKeys
@@ -1039,7 +1058,6 @@ public:
     std::vector<PSBTInput> inputs;
     std::vector<PSBTOutput> outputs;
     std::map<std::vector<unsigned char>, std::vector<unsigned char>> unknown;
-    std::optional<uint32_t> m_version;
     std::set<PSBTProprietary> m_proprietary;
 
     bool IsNull() const;
@@ -1241,10 +1259,12 @@ public:
             throw std::ios_base::failure("No unsigned transaction was provided");
         }
 
+        const uint32_t psbt_ver = GetVersion();
+
         // Read input data
         unsigned int i = 0;
         while (!s.empty() && i < tx->vin.size()) {
-            PSBTInput input;
+            PSBTInput input(psbt_ver);
             s >> input;
             inputs.push_back(input);
 
@@ -1267,7 +1287,7 @@ public:
         // Read output data
         i = 0;
         while (!s.empty() && i < tx->vout.size()) {
-            PSBTOutput output;
+            PSBTOutput output(psbt_ver);
             s >> output;
             outputs.push_back(output);
             ++i;
diff --git a/src/rpc/rawtransaction.cpp b/src/rpc/rawtransaction.cpp
index 0f3cebb5dcf..67067110648 100644
--- a/src/rpc/rawtransaction.cpp
+++ b/src/rpc/rawtransaction.cpp
@@ -1652,10 +1652,10 @@ static RPCMethod createpsbt()
     PartiallySignedTransaction psbtx;
     psbtx.tx = rawTx;
     for (unsigned int i = 0; i < rawTx.vin.size(); ++i) {
-        psbtx.inputs.emplace_back();
+        psbtx.inputs.emplace_back(0);
     }
     for (unsigned int i = 0; i < rawTx.vout.size(); ++i) {
-        psbtx.outputs.emplace_back();
+        psbtx.outputs.emplace_back(0);
     }
 
     // Serialize the PSBT
@@ -1720,10 +1720,10 @@ static RPCMethod converttopsbt()
     PartiallySignedTransaction psbtx;
     psbtx.tx = tx;
     for (unsigned int i = 0; i < tx.vin.size(); ++i) {
-        psbtx.inputs.emplace_back();
+        psbtx.inputs.emplace_back(0);
     }
     for (unsigned int i = 0; i < tx.vout.size(); ++i) {
-        psbtx.outputs.emplace_back();
+        psbtx.outputs.emplace_back(0);
     }
 
     // Serialize the PSBT
diff --git a/src/test/fuzz/deserialize.cpp b/src/test/fuzz/deserialize.cpp
index 1329f471c70..b3f35baa0fc 100644
--- a/src/test/fuzz/deserialize.cpp
+++ b/src/test/fuzz/deserialize.cpp
@@ -192,11 +192,11 @@ FUZZ_TARGET_DESERIALIZE(prefilled_transaction_deserialize, {
     DeserializeFromFuzzingInput(buffer, prefilled_transaction);
 })
 FUZZ_TARGET_DESERIALIZE(psbt_input_deserialize, {
-    PSBTInput psbt_input;
+    PSBTInput psbt_input(0);
     DeserializeFromFuzzingInput(buffer, psbt_input);
 })
 FUZZ_TARGET_DESERIALIZE(psbt_output_deserialize, {
-    PSBTOutput psbt_output;
+    PSBTOutput psbt_output(0);
     DeserializeFromFuzzingInput(buffer, psbt_output);
 })
 FUZZ_TARGET_DESERIALIZE(block_deserialize, {