Implement PSBT proprietary type

src/psbt.h

@@ -21,6 +21,7 @@ static constexpr uint8_t PSBT_MAGIC_BYTES[5] = {'p', 's', 'b', 't', 0xff};
 // Global types
 static constexpr uint8_t PSBT_GLOBAL_UNSIGNED_TX = 0x00;
 static constexpr uint8_t PSBT_GLOBAL_VERSION = 0xFB;
+static constexpr uint8_t PSBT_GLOBAL_PROPRIETARY = 0xFC;
 
 // Input types
 static constexpr uint8_t PSBT_IN_NON_WITNESS_UTXO = 0x00;
@@ -32,11 +33,13 @@ static constexpr uint8_t PSBT_IN_WITNESSSCRIPT = 0x05;
 static constexpr uint8_t PSBT_IN_BIP32_DERIVATION = 0x06;
 static constexpr uint8_t PSBT_IN_SCRIPTSIG = 0x07;
 static constexpr uint8_t PSBT_IN_SCRIPTWITNESS = 0x08;
+static constexpr uint8_t PSBT_IN_PROPRIETARY = 0xFC;
 
 // Output types
 static constexpr uint8_t PSBT_OUT_REDEEMSCRIPT = 0x00;
 static constexpr uint8_t PSBT_OUT_WITNESSSCRIPT = 0x01;
 static constexpr uint8_t PSBT_OUT_BIP32_DERIVATION = 0x02;
+static constexpr uint8_t PSBT_OUT_PROPRIETARY = 0xFC;
 
 // The separator is 0x00. Reading this in means that the unserializer can interpret it
 // as a 0 length key which indicates that this is the separator. The separator has no value.
@@ -49,6 +52,22 @@ const std::streamsize MAX_FILE_SIZE_PSBT = 100000000; // 100 MiB
 // PSBT version number
 static constexpr uint32_t PSBT_HIGHEST_VERSION = 0;
 
+/** A structure for PSBT proprietary types */
+struct PSBTProprietary
+{
+    uint64_t subtype;
+    std::vector<unsigned char> identifier;
+    std::vector<unsigned char> key;
+    std::vector<unsigned char> value;
+
+    bool operator<(const PSBTProprietary &b) const {
+        return key < b.key;
+    }
+    bool operator==(const PSBTProprietary &b) const {
+        return key == b.key;
+    }
+};
+
 /** A structure for PSBTs which contain per-input information */
 struct PSBTInput
 {
@@ -61,6 +80,7 @@ struct PSBTInput
     std::map<CPubKey, KeyOriginInfo> hd_keypaths;
     std::map<CKeyID, SigPair> partial_sigs;
     std::map<std::vector<unsigned char>, std::vector<unsigned char>> unknown;
+    std::set<PSBTProprietary> m_proprietary;
     std::optional<int> sighash_type;
 
     bool IsNull() const;
@@ -122,6 +142,12 @@ struct PSBTInput
             SerializeToVector(s, final_script_witness.stack);
         }
 
+        // Write proprietary things
+        for (const auto& entry : m_proprietary) {
+            s << entry.key;
+            s << entry.value;
+        }
+
         // Write unknown things
         for (auto& entry : unknown) {
             s << entry.first;
@@ -255,6 +281,20 @@ struct PSBTInput
                     UnserializeFromVector(s, final_script_witness.stack);
                     break;
                 }
+                case PSBT_IN_PROPRIETARY:
+                {
+                    PSBTProprietary this_prop;
+                    skey >> this_prop.identifier;
+                    this_prop.subtype = ReadCompactSize(skey);
+                    this_prop.key = key;
+
+                    if (m_proprietary.count(this_prop) > 0) {
+                        throw std::ios_base::failure("Duplicate Key, proprietary key already found");
+                    }
+                    s >> this_prop.value;
+                    m_proprietary.insert(this_prop);
+                    break;
+                }
                 // Unknown stuff
                 default:
                     if (unknown.count(key) > 0) {
@@ -286,6 +326,7 @@ struct PSBTOutput
     CScript witness_script;
     std::map<CPubKey, KeyOriginInfo> hd_keypaths;
     std::map<std::vector<unsigned char>, std::vector<unsigned char>> unknown;
+    std::set<PSBTProprietary> m_proprietary;
 
     bool IsNull() const;
     void FillSignatureData(SignatureData& sigdata) const;
@@ -310,6 +351,12 @@ struct PSBTOutput
         // Write any hd keypaths
         SerializeHDKeypaths(s, hd_keypaths, CompactSizeWriter(PSBT_OUT_BIP32_DERIVATION));
 
+        // Write proprietary things
+        for (const auto& entry : m_proprietary) {
+            s << entry.key;
+            s << entry.value;
+        }
+
         // Write unknown things
         for (auto& entry : unknown) {
             s << entry.first;
@@ -370,6 +417,20 @@ struct PSBTOutput
                     DeserializeHDKeypaths(s, key, hd_keypaths);
                     break;
                 }
+                case PSBT_OUT_PROPRIETARY:
+                {
+                    PSBTProprietary this_prop;
+                    skey >> this_prop.identifier;
+                    this_prop.subtype = ReadCompactSize(skey);
+                    this_prop.key = key;
+
+                    if (m_proprietary.count(this_prop) > 0) {
+                        throw std::ios_base::failure("Duplicate Key, proprietary key already found");
+                    }
+                    s >> this_prop.value;
+                    m_proprietary.insert(this_prop);
+                    break;
+                }
                 // Unknown stuff
                 default: {
                     if (unknown.count(key) > 0) {
@@ -403,6 +464,7 @@ struct PartiallySignedTransaction
     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;
     uint32_t GetVersion() const;
@@ -442,6 +504,12 @@ struct PartiallySignedTransaction
             SerializeToVector(s, *m_version);
         }
 
+        // Write proprietary things
+        for (const auto& entry : m_proprietary) {
+            s << entry.key;
+            s << entry.value;
+        }
+
         // Write the unknown things
         for (auto& entry : unknown) {
             s << entry.first;
@@ -529,6 +597,20 @@ struct PartiallySignedTransaction
                     }
                     break;
                 }
+                case PSBT_GLOBAL_PROPRIETARY:
+                {
+                    PSBTProprietary this_prop;
+                    skey >> this_prop.identifier;
+                    this_prop.subtype = ReadCompactSize(skey);
+                    this_prop.key = key;
+
+                    if (m_proprietary.count(this_prop) > 0) {
+                        throw std::ios_base::failure("Duplicate Key, proprietary key already found");
+                    }
+                    s >> this_prop.value;
+                    m_proprietary.insert(this_prop);
+                    break;
+                }
                 // Unknown stuff
                 default: {
                     if (unknown.count(key) > 0) {