v1.6.2 to fix byte padding bug in short source fingerprint integers

README.md

@@ -12,7 +12,7 @@ Hummingbird requires a minimum of Java 8.
 Hummingbird is hosted in Maven Central and can be added as a dependency with the following:
 
 ```
-implementation('com.sparrowwallet:hummingbird:1.6.1')
+implementation('com.sparrowwallet:hummingbird:1.6.2')
 ```
 
 ## Usage

build.gradle

@@ -16,7 +16,7 @@ apply plugin: 'com.bmuschko.nexus'
 
 archivesBaseName = 'hummingbird'
 group 'com.sparrowwallet'
-version '1.6.1'
+version '1.6.2'
 
 repositories {
     mavenCentral()

src/main/java/com/sparrowwallet/hummingbird/registry/CryptoAccount.java

@@ -47,12 +47,13 @@ public class CryptoAccount extends RegistryItem {
         Map cryptoAccountMap = (Map)cbor;
 
         UnsignedInteger uintMasterFingerprint = (UnsignedInteger)cryptoAccountMap.get(new UnsignedInteger(MASTER_FINGERPRINT_KEY));
+        byte[] masterFingerprint = bigIntegerToBytes(uintMasterFingerprint.getValue(), 4);
         Array outputDescriptors = (Array)cryptoAccountMap.get(new UnsignedInteger(OUTPUT_DESCRIPTORS_KEY));
         List<CryptoOutput> cryptoOutputs = new ArrayList<>(outputDescriptors.getDataItems().size());
         for(DataItem item : outputDescriptors.getDataItems()) {
             cryptoOutputs.add(CryptoOutput.fromCbor(item));
         }
 
-        return new CryptoAccount(uintMasterFingerprint.getValue().toByteArray(), cryptoOutputs);
+        return new CryptoAccount(masterFingerprint, cryptoOutputs);
     }
 }

src/main/java/com/sparrowwallet/hummingbird/registry/CryptoHDKey.java

@@ -176,7 +176,7 @@ public class CryptoHDKey extends RegistryItem {
             } else if(intKey == CHILDREN_KEY) {
                 children = CryptoKeypath.fromCbor(map.get(uintKey));
             } else if(intKey == PARENT_FINGERPRINT_KEY) {
-                parentFingerprint = ((UnsignedInteger)map.get(uintKey)).getValue().toByteArray();
+                parentFingerprint = bigIntegerToBytes(((UnsignedInteger)map.get(uintKey)).getValue(), 4);
             } else if(intKey == NAME_KEY) {
                 name = ((UnicodeString)map.get(uintKey)).getString();
             } else if(intKey == NOTE_KEY) {

src/main/java/com/sparrowwallet/hummingbird/registry/CryptoKeypath.java

@@ -99,7 +99,7 @@ public class CryptoKeypath extends RegistryItem {
                     }
                 }
             } else if(intKey == SOURCE_FINGERPRINT_KEY) {
-                sourceFingerprint = ((UnsignedInteger)map.get(key)).getValue().toByteArray();
+                sourceFingerprint = bigIntegerToBytes(((UnsignedInteger)map.get(key)).getValue(), 4);
             } else if(intKey == DEPTH_KEY) {
                 depth = ((UnsignedInteger)map.get(key)).getValue().intValue();
             }

src/main/java/com/sparrowwallet/hummingbird/registry/RegistryItem.java

@@ -5,6 +5,8 @@ import co.nstant.in.cbor.CborException;
 import com.sparrowwallet.hummingbird.UR;
 
 import java.io.ByteArrayOutputStream;
+import java.math.BigInteger;
+import java.util.Arrays;
 
 public abstract class RegistryItem implements CborSerializable {
     public abstract RegistryType getRegistryType();
@@ -19,4 +21,34 @@ public abstract class RegistryItem implements CborSerializable {
             throw new IllegalArgumentException(e);
         }
     }
+
+    /**
+     * <p>
+     * The regular {@link BigInteger#toByteArray()} includes the sign bit of the number and
+     * might result in an extra byte addition. This method removes this extra byte.
+     * </p>
+     * @param b the integer to format into a byte array
+     * @param numBytes the desired size of the resulting byte array
+     * @return numBytes byte long array.
+     */
+    protected static byte[] bigIntegerToBytes(BigInteger b, int numBytes) {
+        if(b.signum() < 0) {
+            throw new IllegalArgumentException("b must be positive or zero");
+        }
+        if(numBytes <= 0) {
+            throw new IllegalArgumentException("numBytes must be positive");
+        }
+        byte[] src = b.toByteArray();
+        byte[] dest = new byte[numBytes];
+        boolean isFirstByteOnlyForSign = src[0] == 0;
+        int length = isFirstByteOnlyForSign ? src.length - 1 : src.length;
+        if(length > numBytes) {
+            throw new IllegalArgumentException("The given number does not fit in " + numBytes);
+        }
+        int srcPos = isFirstByteOnlyForSign ? 1 : 0;
+        int destPos = numBytes - length;
+        System.arraycopy(src, srcPos, dest, destPos, length);
+        Arrays.fill(src, (byte)0);
+        return dest;
+    }
 }

src/test/java/com/sparrowwallet/hummingbird/registry/CryptoHDKeyTest.java

@@ -61,4 +61,38 @@ public class CryptoHDKeyTest {
         String ur = "ur:crypto-hdkey/otaxhdclaxpsfswtmnsknejlceuogoqdaelbmhwnptlrecwpeehhfnpsfzbauecatleotsheptaahdcxvsbbhlrpdivdmelovygscttbstjpnllpasmtcaecmyvswpwftssffxrkcabsmdcxamtaaddyoeadlaaocylpgrstlfiewtseje";
         Assert.assertEquals(ur, cryptoHDKey.toUR().toString());
     }
+
+    @Test
+    public void testZeroMasterFingerprint() throws CborException {
+        String hex = "a303582103ac3df08ec59f6f1cdc55b3007f90f1a98435ec345c3cac400ede1dd533d75fa9045820e8145db627e79188e14c1fd6c772998509961d358fe8ecf3d7cc43bb1d0f952006d90130a201800200";
+        byte[] data = TestUtils.hexToBytes(hex);
+        List<DataItem> items = CborDecoder.decode(data);
+        CryptoHDKey cryptoHDKey = CryptoHDKey.fromCbor(items.get(0));
+        Assert.assertFalse(cryptoHDKey.isMaster());
+        Assert.assertFalse(cryptoHDKey.isPrivateKey());
+        Assert.assertEquals("03ac3df08ec59f6f1cdc55b3007f90f1a98435ec345c3cac400ede1dd533d75fa9", TestUtils.bytesToHex(cryptoHDKey.getKey()));
+        Assert.assertEquals("e8145db627e79188e14c1fd6c772998509961d358fe8ecf3d7cc43bb1d0f9520", TestUtils.bytesToHex(cryptoHDKey.getChainCode()));
+        Assert.assertNull(cryptoHDKey.getOrigin().getPath());
+        Assert.assertEquals("00000000", TestUtils.bytesToHex(cryptoHDKey.getOrigin().getSourceFingerprint()));
+        Assert.assertEquals(hex.toLowerCase(), TestUtils.encode(cryptoHDKey.toCbor()));
+        String ur = "ur:crypto-hdkey/otaxhdclaxpsfswtmnsknejlceuogoqdaelbmhwnptlrecwpeehhfnpsfzbauecatleotsheptaahdcxvsbbhlrpdivdmelovygscttbstjpnllpasmtcaecmyvswpwftssffxrkcabsmdcxamtaaddyoeadlaaoaebkoxdive";
+        Assert.assertEquals(ur, cryptoHDKey.toUR().toString());
+    }
+
+    @Test
+    public void testShortMasterFingerprint() throws CborException {
+        String hex = "A303582103AC3DF08EC59F6F1CDC55B3007F90F1A98435EC345C3CAC400EDE1DD533D75FA9045820E8145DB627E79188E14C1FD6C772998509961D358FE8ECF3D7CC43BB1D0F952006D90130A201800218FF";
+        byte[] data = TestUtils.hexToBytes(hex);
+        List<DataItem> items = CborDecoder.decode(data);
+        CryptoHDKey cryptoHDKey = CryptoHDKey.fromCbor(items.get(0));
+        Assert.assertFalse(cryptoHDKey.isMaster());
+        Assert.assertFalse(cryptoHDKey.isPrivateKey());
+        Assert.assertEquals("03ac3df08ec59f6f1cdc55b3007f90f1a98435ec345c3cac400ede1dd533d75fa9", TestUtils.bytesToHex(cryptoHDKey.getKey()));
+        Assert.assertEquals("e8145db627e79188e14c1fd6c772998509961d358fe8ecf3d7cc43bb1d0f9520", TestUtils.bytesToHex(cryptoHDKey.getChainCode()));
+        Assert.assertNull(cryptoHDKey.getOrigin().getPath());
+        Assert.assertEquals("000000ff", TestUtils.bytesToHex(cryptoHDKey.getOrigin().getSourceFingerprint()));
+        Assert.assertEquals(hex.toLowerCase(), TestUtils.encode(cryptoHDKey.toCbor()));
+        String ur = "ur:crypto-hdkey/otaxhdclaxpsfswtmnsknejlceuogoqdaelbmhwnptlrecwpeehhfnpsfzbauecatleotsheptaahdcxvsbbhlrpdivdmelovygscttbstjpnllpasmtcaecmyvswpwftssffxrkcabsmdcxamtaaddyoeadlaaocszmtnkocyct";
+        Assert.assertEquals(ur, cryptoHDKey.toUR().toString());
+    }
 }