sign psbt inputs

src/main/java/com/sparrowwallet/drongo/ExtendedKey.java

@@ -73,11 +73,12 @@ public class ExtendedKey {
         return buffer.array();
     }
 
-    public static ExtendedKey fromDescriptor(String extPubKey) {
+    public static ExtendedKey fromDescriptor(String descriptor) {
-        byte[] serializedKey = Base58.decodeChecked(extPubKey);
+        byte[] serializedKey = Base58.decodeChecked(descriptor);
         ByteBuffer buffer = ByteBuffer.wrap(serializedKey);
-        int header = buffer.getInt();
+        int headerInt = buffer.getInt();
-        if(!Header.isValidHeader(header)) {
+        Header header = Header.getHeader(headerInt);
+        if(header == null) {
             throw new IllegalArgumentException("Unknown header bytes: " + DeterministicKey.toBase58(serializedKey).substring(0, 4));
         }
 
@@ -106,9 +107,14 @@ public class ExtendedKey {
             throw new IllegalArgumentException("Found unexpected data in key");
         }
 
+        if(header.isPrivate()) {
+            DeterministicKey prvKey = HDKeyDerivation.createMasterPrivKeyFromBytes(Arrays.copyOfRange(data, 1, 33), chainCode, path);
+            return new ExtendedKey(prvKey, parentFingerprint, childNumber);
+        } else {
             DeterministicKey pubKey = new DeterministicKey(path, chainCode, new LazyECPoint(ECKey.CURVE.getCurve(), data), depth, parentFingerprint);
             return new ExtendedKey(pubKey, parentFingerprint, childNumber);
         }
+    }
 
     public static boolean isValid(String extPubKey) {
         try {
@@ -206,14 +212,14 @@ public class ExtendedKey {
             return name.endsWith("prv");
         }
 
-        public static boolean isValidHeader(int header) {
+        public static Header getHeader(int header) {
             for(Header extendedKeyHeader : Header.values()) {
                 if(header == extendedKeyHeader.header) {
-                    return true;
+                    return extendedKeyHeader;
                 }
             }
 
-            return false;
+            return null;
         }
     }
 }

src/main/java/com/sparrowwallet/drongo/psbt/PSBT.java

@@ -84,7 +84,7 @@ public class PSBT {
             Map<ECKey, KeyDerivation> derivedPublicKeys = new LinkedHashMap<>();
             for(Keystore keystore : wallet.getKeystores()) {
                 WalletNode walletNode = utxoEntry.getValue();
-                derivedPublicKeys.put(keystore.getKey(walletNode.getKeyPurpose(), walletNode.getIndex()), keystore.getKeyDerivation());
+                derivedPublicKeys.put(keystore.getPubKey(walletNode), keystore.getKeyDerivation());
             }
 
             PSBTInput psbtInput = new PSBTInput(wallet.getScriptType(), transaction, inputIndex, utxo, utxoIndex, redeemScript, witnessScript, derivedPublicKeys, Collections.emptyMap());
@@ -119,7 +119,7 @@ public class PSBT {
 
                 Map<ECKey, KeyDerivation> derivedPublicKeys = new LinkedHashMap<>();
                 for(Keystore keystore : wallet.getKeystores()) {
-                    derivedPublicKeys.put(keystore.getKey(outputNode.getKeyPurpose(), outputNode.getIndex()), keystore.getKeyDerivation());
+                    derivedPublicKeys.put(keystore.getPubKey(outputNode), keystore.getKeyDerivation());
                 }
 
                 PSBTOutput walletOutput = new PSBTOutput(redeemScript, witnessScript, derivedPublicKeys, Collections.emptyMap());

src/main/java/com/sparrowwallet/drongo/psbt/PSBTInput.java

@@ -280,7 +280,7 @@ public class PSBTInput {
         }
     }
 
-    boolean sign(ECKey privKey) {
+    public boolean sign(ECKey privKey) {
         SigHash localSigHash = getSigHash();
         if(localSigHash == null) {
             //Assume SigHash.ALL

src/main/java/com/sparrowwallet/drongo/wallet/Keystore.java

@@ -101,14 +101,26 @@ public class Keystore {
     public ExtendedKey getExtendedPrivateKey() throws MnemonicException {
         List<ChildNumber> derivation = getKeyDerivation().getDerivation();
         DeterministicKey derivedKey = getExtendedMasterPrivateKey().getKey(derivation);
-        return new ExtendedKey(derivedKey, derivedKey.getParentFingerprint(), derivation.get(derivation.size() - 1));
+        ExtendedKey xprv = new ExtendedKey(derivedKey, derivedKey.getParentFingerprint(), derivation.get(derivation.size() - 1));
+        //Recreate from xprv string to reset path to single ChildNumber at the derived depth
+        return ExtendedKey.fromDescriptor(xprv.toString());
     }
 
-    public DeterministicKey getKey(WalletNode walletNode) {
+    public DeterministicKey getKey(WalletNode walletNode) throws MnemonicException {
         return getKey(walletNode.getKeyPurpose(), walletNode.getIndex());
     }
 
-    public DeterministicKey getKey(KeyPurpose keyPurpose, int keyIndex) {
+    public DeterministicKey getKey(KeyPurpose keyPurpose, int keyIndex) throws MnemonicException {
+        ExtendedKey extendedPrivateKey = getExtendedPrivateKey();
+        List<ChildNumber> derivation = List.of(extendedPrivateKey.getKeyChildNumber(), keyPurpose.getPathIndex(), new ChildNumber(keyIndex));
+        return extendedPrivateKey.getKey(derivation);
+    }
+
+    public DeterministicKey getPubKey(WalletNode walletNode) {
+        return getPubKey(walletNode.getKeyPurpose(), walletNode.getIndex());
+    }
+
+    public DeterministicKey getPubKey(KeyPurpose keyPurpose, int keyIndex) {
         List<ChildNumber> derivation = List.of(extendedPublicKey.getKeyChildNumber(), keyPurpose.getPathIndex(), new ChildNumber(keyIndex));
         return extendedPublicKey.getKey(derivation);
     }

src/main/java/com/sparrowwallet/drongo/wallet/Wallet.java

@@ -169,7 +169,7 @@ public class Wallet {
         }
 
         Keystore keystore = getKeystores().get(0);
-        return keystore.getKey(keyPurpose, index);
+        return keystore.getPubKey(keyPurpose, index);
     }
 
     public List<ECKey> getPubKeys(WalletNode node) {
@@ -183,7 +183,7 @@ public class Wallet {
             throw new UnsupportedOperationException("Cannot determine public keys for a custom policy");
         }
 
-        return getKeystores().stream().map(keystore -> keystore.getKey(keyPurpose, index)).collect(Collectors.toList());
+        return getKeystores().stream().map(keystore -> keystore.getPubKey(keyPurpose, index)).collect(Collectors.toList());
     }
 
     public Address getAddress(WalletNode node) {
@@ -615,7 +615,7 @@ public class Wallet {
 
         for(PSBTInput psbtInput : signingNodes.keySet()) {
             WalletNode walletNode = signingNodes.get(psbtInput);
-            Map<ECKey, Keystore> keystoreKeysForNode = getKeystores().stream().collect(Collectors.toMap(keystore -> keystore.getKey(walletNode), Function.identity(),
+            Map<ECKey, Keystore> keystoreKeysForNode = getKeystores().stream().collect(Collectors.toMap(keystore -> keystore.getPubKey(walletNode), Function.identity(),
                     (u, v) -> { throw new IllegalStateException("Duplicate keys from different keystores for node " + walletNode.getDerivationPath()); },
                     LinkedHashMap::new));
 
@@ -628,6 +628,19 @@ public class Wallet {
         return signedKeystores;
     }
 
+    public void sign(PSBT psbt) throws MnemonicException {
+        Map<PSBTInput, WalletNode> signingNodes = getSigningNodes(psbt);
+        for(Keystore keystore : getKeystores()) {
+            if(keystore.hasSeed()) {
+                for(Map.Entry<PSBTInput, WalletNode> signingEntry : signingNodes.entrySet()) {
+                    ECKey privKey = keystore.getKey(signingEntry.getValue());
+                    PSBTInput psbtInput = signingEntry.getKey();
+                    psbtInput.sign(privKey);
+                }
+            }
+        }
+    }
+
     public BitcoinUnit getAutoUnit() {
         for(KeyPurpose keyPurpose : KeyPurpose.values()) {
             for(WalletNode addressNode : getNode(keyPurpose).getChildren()) {