Updated and fixed JavaDoc

domain/src/main/java/ch/dissem/bitmessage/BitmessageContext.java

@@ -44,7 +44,7 @@ import static ch.dissem.bitmessage.utils.UnixTime.DAY;
 
 /**
  * Use this class if you want to create a Bitmessage client.
- * <p/>
+ * <p>
  * You'll need the Builder to create a BitmessageContext, and set the following properties:
  * <ul>
  * <li>addressRepo</li>
@@ -55,8 +55,10 @@ import static ch.dissem.bitmessage.utils.UnixTime.DAY;
  * <li>streams</li>
  * </ul>
  * The default implementations in the different module builds can be used.
- * <p/>
+ * </p>
+ * <p>
  * The port defaults to 8444 (the default Bitmessage port)
+ * </p>
  */
 public class BitmessageContext {
     public static final int CURRENT_VERSION = 3;

domain/src/main/java/ch/dissem/bitmessage/InternalContext.java

@@ -35,8 +35,9 @@ import static ch.dissem.bitmessage.utils.UnixTime.DAY;
  * The internal context should normally only be used for port implementations. If you need it in your client
  * implementation, you're either doing something wrong, something very weird, or the BitmessageContext should
  * get extended.
- * <p/>
+ * <p>
  * On the other hand, if you need the BitmessageContext in a port implementation, the same thing might apply.
+ * </p>
  */
 public class InternalContext {
     private final static Logger LOG = LoggerFactory.getLogger(InternalContext.class);

domain/src/main/java/ch/dissem/bitmessage/entity/BitmessageAddress.java

@@ -158,7 +158,7 @@ public class BitmessageAddress {
     }
 
     /**
-     * Returns the private key used to decrypt Pubkey objects (for v4 addresses) and broadcasts.
+     * @return the private key used to decrypt Pubkey objects (for v4 addresses) and broadcasts.
      */
     public byte[] getPublicDecryptionKey() {
         return publicDecryptionKey;

domain/src/main/java/ch/dissem/bitmessage/entity/payload/CryptoBox.java

@@ -47,11 +47,11 @@ public class CryptoBox implements Streamable {
     private final byte[] mac;
     private byte[] encrypted;
 
-    public CryptoBox(Streamable data, byte[] encryptionKey) {
+    public CryptoBox(Streamable data, byte[] encryptionKey) throws IOException {
         this(data, Security.keyToPoint(encryptionKey));
     }
 
-    public CryptoBox(Streamable data, ECPoint K) {
+    public CryptoBox(Streamable data, ECPoint K) throws IOException {
         curveType = 0x02CA;
 
         // 1. The destination public key is called K.
@@ -71,7 +71,7 @@ public class CryptoBox implements Streamable {
         byte[] key_m = Arrays.copyOfRange(H, 32, 64);
         // 7. Pad the input text to a multiple of 16 bytes, in accordance to PKCS7.
         // 8. Encrypt the data with AES-256-CBC, using IV as initialization vector, key_e as encryption key and the padded input text as payload. Call the output cipher text.
-        encrypted = crypt(true, Bytes.from(data), key_e);
+        encrypted = crypt(true, Encode.bytes(data), key_e);
         // 9. Calculate a 32 byte MAC with HMACSHA256, using key_m as salt and IV + R + cipher text as data. Call the output MAC.
         mac = calculateMac(key_m);
 
@@ -99,6 +99,9 @@ public class CryptoBox implements Streamable {
     }
 
     /**
+     * @param privateKey a private key, typically should be 32 bytes long
+     * @return an InputStream yielding the decrypted data
+     * @throws DecryptionFailedException if the payload can't be decrypted using this private key
      * @see <a href='https://bitmessage.org/wiki/Encryption#Decryption'>https://bitmessage.org/wiki/Encryption#Decryption</a>
      */
     public InputStream decrypt(byte[] privateKey) throws DecryptionFailedException {

domain/src/main/java/ch/dissem/bitmessage/entity/payload/GetPubkey.java

@@ -50,7 +50,7 @@ public class GetPubkey extends ObjectPayload {
     }
 
     /**
-     * Returns an array of bytes that represent either the ripe, or the tag of an address, depending on the
+     * @return an array of bytes that represent either the ripe, or the tag of an address, depending on the
      * address version.
      */
     public byte[] getRipeTag() {

domain/src/main/java/ch/dissem/bitmessage/entity/payload/ObjectPayload.java

@@ -50,7 +50,7 @@ public abstract class ObjectPayload implements Streamable {
     }
 
     /**
-     * The ECDSA signature which, as of protocol v3, covers the object header starting with the time,
+     * @return the ECDSA signature which, as of protocol v3, covers the object header starting with the time,
      * appended with the data described in this table down to the extra_bytes. Therefore, this must
      * be checked and set in the {@link ObjectMessage} object.
      */

domain/src/main/java/ch/dissem/bitmessage/entity/valueobject/Label.java

@@ -31,12 +31,15 @@ public class Label {
     }
 
     /**
-     * RGBA representation for the color.
+     * @return RGBA representation for the color.
      */
     public int getColor() {
         return color;
     }
 
+    /**
+     * @param color RGBA representation for the color.
+     */
     public void setColor(int color) {
         this.color = color;
     }
@@ -50,14 +53,14 @@ public class Label {
         return id;
     }
 
-    public Type getType() {
-        return type;
-    }
-
     public void setId(Object id) {
         this.id = id;
     }
 
+    public Type getType() {
+        return type;
+    }
+
     @Override
     public boolean equals(Object o) {
         if (this == o) return true;

domain/src/main/java/ch/dissem/bitmessage/ports/AddressRepository.java

@@ -26,7 +26,7 @@ public interface AddressRepository {
     BitmessageAddress findIdentity(byte[] ripeOrTag);
 
     /**
-     * Returns all Bitmessage addresses that belong to this user, i.e. have a private key.
+     * @return all Bitmessage addresses that belong to this user, i.e. have a private key.
      */
     List<BitmessageAddress> getIdentities();
 
@@ -35,7 +35,7 @@ public interface AddressRepository {
     List<BitmessageAddress> getSubscriptions(long broadcastVersion);
 
     /**
-     * Returns all Bitmessage addresses that have no private key.
+     * @return all Bitmessage addresses that have no private key.
      */
     List<BitmessageAddress> getContacts();
 

domain/src/main/java/ch/dissem/bitmessage/utils/Base58.java

@@ -29,9 +29,8 @@ import static java.util.Arrays.copyOfRange;
  * @author Christian Basler: I removed some dependencies to the BitcoinJ code so it can be used here more easily.
  */
 public class Base58 {
-    private static char[] ALPHABET = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz".toCharArray();
-
     private static final int[] INDEXES = new int[128];
+    private static char[] ALPHABET = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz".toCharArray();
 
     static {
         for (int i = 0; i < INDEXES.length; i++) {
@@ -44,6 +43,9 @@ public class Base58 {
 
     /**
      * Encodes the given bytes in base58. No checksum is appended.
+     *
+     * @param input to encode
+     * @return base58 encoded input
      */
     public static String encode(byte[] input) {
         if (input.length == 0) {

domain/src/main/java/ch/dissem/bitmessage/utils/Bytes.java

@@ -38,6 +38,9 @@ public class Bytes {
 
     /**
      * Increases nonce by value, which is used as an unsigned byte value.
+     *
+     * @param nonce an unsigned number
+     * @param value to be added to nonce
      */
     public static void inc(byte[] nonce, byte value) {
         int i = nonce.length - 1;
@@ -54,7 +57,7 @@ public class Bytes {
     }
 
     /**
-     * Returns true if a < b.
+     * @return true if a &lt; b.
      */
     public static boolean lt(byte[] a, byte[] b) {
         byte[] max = (a.length > b.length ? a : b);
@@ -73,7 +76,7 @@ public class Bytes {
     }
 
     /**
-     * Returns true if a < b, where the first [size] bytes are used as the numbers to check.
+     * @return true if a &lt; b, where the first [size] bytes are used as the numbers to check.
      */
     public static boolean lt(byte[] a, byte[] b, int size) {
         for (int i = 0; i < size; i++) {
@@ -91,7 +94,7 @@ public class Bytes {
     }
 
     /**
-     * Returns a new byte array of length, left-padded with '0'.
+     * @return a new byte array of length, left-padded with '0'.
      */
     public static byte[] expand(byte[] source, int size) {
         byte[] result = new byte[size];
@@ -100,7 +103,7 @@ public class Bytes {
     }
 
     /**
-     * Returns a new byte array containing the first <em>size</em> bytes of the given array.
+     * @return a new byte array containing the first <em>size</em> bytes of the given array.
      */
     public static byte[] truncate(byte[] source, int size) {
         byte[] result = new byte[size];
@@ -109,7 +112,7 @@ public class Bytes {
     }
 
     /**
-     * Returns the byte array that hex represents. This is meant for test use and should be rewritten if used in
+     * @return the byte array that hex represents. This is meant for test use and should be rewritten if used in
      * production code.
      */
     public static byte[] fromHex(String hex) {
@@ -136,7 +139,7 @@ public class Bytes {
     }
 
     /**
-     * Returns the number of leading '0' of a byte array.
+     * @return the number of leading '0' of a byte array.
      */
     public static int numberOfLeadingZeros(byte[] bytes) {
         int i;
@@ -145,24 +148,4 @@ public class Bytes {
         }
         return i;
     }
-
-    /**
-     * Returns a copy of bytes with leading zeroes stripped.
-     */
-    public static byte[] stripLeadingZeros(byte[] bytes) {
-        return Arrays.copyOfRange(bytes, numberOfLeadingZeros(bytes), bytes.length);
-    }
-
-    /**
-     * Returns the byte array of the serialized data.
-     */
-    public static byte[] from(Streamable data) {
-        try {
-            ByteArrayOutputStream out = new ByteArrayOutputStream();
-            data.write(out);
-            return out.toByteArray();
-        } catch (IOException e) {
-            throw new RuntimeException(e);
-        }
-    }
 }

domain/src/main/java/ch/dissem/bitmessage/utils/Collections.java

@@ -25,8 +25,11 @@ public class Collections {
     private final static Random RANDOM = new Random();
 
     /**
-     * Returns a random subset of the given collection, or a copy of the collection if it's not larger than count.
+     * @param count      the number of elements to return (if possible)
-     * The randomness
+     * @param collection the collection to take samples from
+     * @return a random subset of the given collection, or a copy of the collection if it's not larger than count. The
+     * result is by no means securely random, but should be random enough so not the same objects get selected over
+     * and over again.
      */
     public static <T> List<T> selectRandom(int count, Collection<T> collection) {
         ArrayList<T> result = new ArrayList<>(count);

domain/src/main/java/ch/dissem/bitmessage/utils/Encode.java

@@ -112,7 +112,9 @@ public class Encode {
     }
 
     /**
-     * Returns an array of bytes representing the given streamable object.
+     * @param streamable the object to be serialized
+     * @return an array of bytes representing the given streamable object.
+     * @throws IOException if an I/O error occurs.
      */
     public static byte[] bytes(Streamable streamable) throws IOException {
         ByteArrayOutputStream stream = new ByteArrayOutputStream();
@@ -121,8 +123,10 @@ public class Encode {
     }
 
     /**
-     * Returns the bytes of the given streamable object, 0-padded such that the final
+     * @param streamable the object to be serialized
-     * length is x*padding.
+     * @param padding    the result will be padded such that its length is a multiple of <em>padding</em>
+     * @return the bytes of the given {@link Streamable} object, 0-padded such that the final length is x*padding.
+     * @throws IOException if an I/O error occurs.
      */
     public static byte[] bytes(Streamable streamable, int padding) throws IOException {
         ByteArrayOutputStream stream = new ByteArrayOutputStream();

domain/src/main/java/ch/dissem/bitmessage/utils/Security.java

@@ -40,7 +40,8 @@ import java.security.spec.KeySpec;
 import java.util.Arrays;
 
 /**
- * Provides some methods to help with hashing and encryption.
+ * Provides some methods to help with hashing and encryption. All randoms are created using {@link SecureRandom},
+ * which should be secure enough.
  */
 public class Security {
     public static final Logger LOG = LoggerFactory.getLogger(Security.class);
@@ -52,10 +53,26 @@ public class Security {
         java.security.Security.addProvider(new BouncyCastleProvider());
     }
 
+    /**
+     * A helper method to calculate SHA-512 hashes. Please note that a new {@link MessageDigest} object is created at
+     * each call (to ensure thread safety), so you shouldn't use this if you need to do many hash calculations in
+     * success on the same thread.
+     *
+     * @param data to get hashed
+     * @return SHA-512 hash of data
+     */
     public static byte[] sha512(byte[]... data) {
         return hash("SHA-512", data);
     }
 
+    /**
+     * A helper method to calculate doubleSHA-512 hashes. Please note that a new {@link MessageDigest} object is created
+     * at each call (to ensure thread safety), so you shouldn't use this if you need to do many hash calculations in
+     * success on the same thread.
+     *
+     * @param data to get hashed
+     * @return SHA-512 hash of data
+     */
     public static byte[] doubleSha512(byte[]... data) {
         MessageDigest mda = md("SHA-512");
         for (byte[] d : data) {
@@ -64,33 +81,97 @@ public class Security {
         return mda.digest(mda.digest());
     }
 
+    /**
+     * A helper method to calculate double SHA-512 hashes. This method allows to only use a part of the available bytes
+     * to use for the hash calculation.
+     * <p>
+     * Please note that a new {@link MessageDigest} object is created at each call (to ensure thread safety), so you
+     * shouldn't use this if you need to do many hash calculations in short order on the same thread.
+     * </p>
+     *
+     * @param data   to get hashed
+     * @param length number of bytes to be taken into account
+     * @return SHA-512 hash of data
+     */
     public static byte[] doubleSha512(byte[] data, int length) {
         MessageDigest mda = md("SHA-512");
         mda.update(data, 0, length);
         return mda.digest(mda.digest());
     }
 
+
+    /**
+     * A helper method to calculate RIPEMD-160 hashes. Supplying multiple byte arrays has the same result as a
+     * concatenation of all arrays, but might perform better.
+     * <p>
+     * Please note that a new {@link MessageDigest} object is created at
+     * each call (to ensure thread safety), so you shouldn't use this if you need to do many hash calculations in short
+     * order on the same thread.
+     * </p>
+     *
+     * @param data to get hashed
+     * @return RIPEMD-160 hash of data
+     */
     public static byte[] ripemd160(byte[]... data) {
         return hash("RIPEMD160", data);
     }
 
+    /**
+     * A helper method to calculate double SHA-256 hashes. This method allows to only use a part of the available bytes
+     * to use for the hash calculation.
+     * <p>
+     * Please note that a new {@link MessageDigest} object is created at
+     * each call (to ensure thread safety), so you shouldn't use this if you need to do many hash calculations in short
+     * order on the same thread.
+     * </p>
+     *
+     * @param data   to get hashed
+     * @param length number of bytes to be taken into account
+     * @return SHA-256 hash of data
+     */
     public static byte[] doubleSha256(byte[] data, int length) {
         MessageDigest mda = md("SHA-256");
         mda.update(data, 0, length);
         return mda.digest(mda.digest());
     }
 
+    /**
+     * A helper method to calculate SHA-1 hashes. Supplying multiple byte arrays has the same result as a
+     * concatenation of all arrays, but might perform better.
+     * <p>
+     * Please note that a new {@link MessageDigest} object is created at
+     * each call (to ensure thread safety), so you shouldn't use this if you need to do many hash calculations in short
+     * order on the same thread.
+     * </p>
+     *
+     * @param data to get hashed
+     * @return SHA hash of data
+     */
     public static byte[] sha1(byte[]... data) {
         return hash("SHA-1", data);
     }
 
+    /**
+     * @param length number of bytes to return
+     * @return an array of the given size containing random bytes
+     */
     public static byte[] randomBytes(int length) {
         byte[] result = new byte[length];
         RANDOM.nextBytes(result);
         return result;
     }
 
-    public static void doProofOfWork(ObjectMessage object, ProofOfWorkEngine worker, long nonceTrialsPerByte, long extraBytes) {
+    /**
+     * Calculates the proof of work. This might take a long time, depending on the hardware, message size and time to
+     * live.
+     *
+     * @param object             to do the proof of work for
+     * @param worker             doing the actual proof of work
+     * @param nonceTrialsPerByte difficulty
+     * @param extraBytes         bytes to add to the object size (makes it more difficult to send small messages)
+     */
+    public static void doProofOfWork(ObjectMessage object, ProofOfWorkEngine worker, long nonceTrialsPerByte,
+                                     long extraBytes) {
         try {
             if (nonceTrialsPerByte < 1000) nonceTrialsPerByte = 1000;
             if (extraBytes < 1000) extraBytes = 1000;
@@ -107,9 +188,13 @@ public class Security {
     }
 
     /**
-     * @throws InsufficientProofOfWorkException if proof of work doesn't check out
+     * @param object             to be checked
+     * @param nonceTrialsPerByte difficulty
+     * @param extraBytes         bytes to add to the object size
+     * @throws InsufficientProofOfWorkException if proof of work doesn't check out (makes it more difficult to send small messages)
      */
-    public static void checkProofOfWork(ObjectMessage object, long nonceTrialsPerByte, long extraBytes) throws IOException {
+    public static void checkProofOfWork(ObjectMessage object, long nonceTrialsPerByte, long extraBytes)
+            throws IOException {
         byte[] target = getProofOfWorkTarget(object, nonceTrialsPerByte, extraBytes);
         byte[] value = Security.doubleSha512(object.getNonce(), getInitialHash(object));
         if (Bytes.lt(target, value, 8)) {
@@ -146,6 +231,13 @@ public class Security {
         }
     }
 
+    /**
+     * Calculates the MAC for a message (data)
+     *
+     * @param key_m the symmetric key used
+     * @param data  the message data to calculate the MAC for
+     * @return the MAC
+     */
     public static byte[] mac(byte[] key_m, byte[] data) {
         try {
             Mac mac = Mac.getInstance("HmacSHA256", "BC");
@@ -156,6 +248,18 @@ public class Security {
         }
     }
 
+    /**
+     * Create a new public key fom given private keys.
+     *
+     * @param version              of the public key / address
+     * @param stream               of the address
+     * @param privateSigningKey    private key used for signing
+     * @param privateEncryptionKey private key used for encryption
+     * @param nonceTrialsPerByte   proof of work difficulty
+     * @param extraBytes           bytes to add for the proof of work (make it harder for small messages)
+     * @param features             of the address
+     * @return a public key object
+     */
     public static Pubkey createPubkey(long version, long stream, byte[] privateSigningKey, byte[] privateEncryptionKey,
                                       long nonceTrialsPerByte, long extraBytes, Pubkey.Feature... features) {
         return Factory.createPubkey(version, stream,
@@ -164,10 +268,18 @@ public class Security {
                 nonceTrialsPerByte, extraBytes, features);
     }
 
+    /**
+     * @param privateKey private key as byte array
+     * @return a public key corresponding to the given private key
+     */
     public static ECPoint createPublicKey(byte[] privateKey) {
         return EC_CURVE_PARAMETERS.getG().multiply(keyToBigInt(privateKey)).normalize();
     }
 
+    /**
+     * @param privateKey private key as byte array
+     * @return a big integer representation (unsigned) of the given bytes
+     */
     public static BigInteger keyToBigInt(byte[] privateKey) {
         return new BigInteger(1, privateKey);
     }
@@ -185,7 +297,13 @@ public class Security {
         );
     }
 
-    public static boolean isSignatureValid(byte[] bytesToSign, byte[] signature, Pubkey pubkey) {
+    /**
+     * @param data      to check
+     * @param signature the signature of the message
+     * @param pubkey    the sender's public key
+     * @return true if the signature is valid, false otherwise
+     */
+    public static boolean isSignatureValid(byte[] data, byte[] signature, Pubkey pubkey) {
         try {
             ECParameterSpec spec = new ECParameterSpec(
                     EC_CURVE_PARAMETERS.getCurve(),
@@ -201,13 +319,20 @@ public class Security {
 
             Signature sig = Signature.getInstance("ECDSA", "BC");
             sig.initVerify(publicKey);
-            sig.update(bytesToSign);
+            sig.update(data);
             return sig.verify(signature);
         } catch (Exception e) {
             throw new RuntimeException(e);
         }
     }
 
+    /**
+     * Calculate the signature of data, using the given private key.
+     *
+     * @param data       to be signed
+     * @param privateKey to be used for signing
+     * @return the signature
+     */
     public static byte[] getSignature(byte[] data, ch.dissem.bitmessage.entity.valueobject.PrivateKey privateKey) {
         try {
             ECParameterSpec spec = new ECParameterSpec(
@@ -231,6 +356,9 @@ public class Security {
         }
     }
 
+    /**
+     * @return a random number of type long
+     */
     public static long randomNonce() {
         return RANDOM.nextLong();
     }

domain/src/main/java/ch/dissem/bitmessage/utils/UnixTime.java

@@ -30,7 +30,7 @@ public class UnixTime {
     public static final long DAY = 24 * HOUR;
 
     /**
-     * Returns the time in second based Unix time ({@link System#currentTimeMillis()}/1000)
+     * @return the time in second based Unix time ({@link System#currentTimeMillis()}/1000)
      */
     public static long now() {
         return System.currentTimeMillis() / 1000;
@@ -38,6 +38,9 @@ public class UnixTime {
 
     /**
      * Same as {@link #now()} + shiftSeconds, but might be more readable.
+     *
+     * @param shiftSeconds number of seconds from now we're interested in
+     * @return the Unix time in shiftSeconds seconds / shiftSeconds seconds ago
      */
     public static long now(long shiftSeconds) {
         return (System.currentTimeMillis() / 1000) + shiftSeconds;