Objects necessary for collections

core/src/main/groovy/com/muwire/core/collections/FileCollection.groovy

@@ -0,0 +1,117 @@
+package com.muwire.core.collections
+
+import com.muwire.core.Constants
+import com.muwire.core.InfoHash
+import com.muwire.core.Name
+import com.muwire.core.Persona
+import com.muwire.core.util.DataUtil
+
+import net.i2p.crypto.DSAEngine
+import net.i2p.data.Signature
+import net.i2p.data.SigningPrivateKey
+
+class FileCollection {
+    
+    private final long timestamp
+    private final Persona author
+    private final String comment
+    private final byte[] sig
+    
+    private volatile byte[] payload
+    
+    private final Set<FileCollectionItem> files = new LinkedHashSet<>()
+    
+    FileCollection(long timestamp, Persona author, String comment, Set<FileCollectionItem> files,
+        SigningPrivateKey spk) {
+        this.timestamp = timestamp;
+        this.author = author;
+        this.comment = comment
+        this.files = files
+        
+        byte [] signablePayload = signablePayload()
+        Signature signature = DSAEngine.getInstance().sign(signablePayload, spk)
+        this.sig = signature.getData()
+    }
+    
+    FileCollection(InputStream is) {
+        DataInputStream dis = new DataInputStream(is)
+        byte version = (byte) dis.read()
+        if (version != Constants.COLLECTION_VERSION)
+            throw new InvalidCollectionException("unsupported version $version")
+        
+        int numFiles = dis.readUnsignedShort()
+        
+        author = new Persona(dis)
+        timestamp = dis.readLong()
+        def commentName = new Name(dis)
+        comment = commentName.name
+        
+        numFiles.times { 
+            files.add(new FileCollectionItem(dis))
+        }
+        
+        sig = new byte[Constants.SIG_TYPE.getSigLen()]
+        dis.readFully(sig)
+        
+        if (!verify())
+            throw new InvalidCollectionException("invalid signature")
+    }
+    
+    private boolean verify() {
+        def baos = new ByteArrayOutputStream()
+        def daos = new DataOutputStream(baos)
+        
+        daos.writeByte(Constants.COLLECTION_VERSION)
+        daos.writeShort(files.size())
+        author.write(daos)
+        daos.writeLong(timestamp)
+        def commentName = new Name(comment)
+        commentName.write(daos)
+        files.each { 
+            it.write(daos)
+        }
+        
+        daos.close()
+        byte [] payload = baos.toByteArray()
+        
+        def spk = author.destination.getSigningPublicKey()
+        def signature = new Signature(spk.getType(), sig)
+        DSAEngine.getInstance().verifySignature(signature, payload, spk)
+    }
+    
+    private byte[] signablePayload() {
+        
+        def baos = new ByteArrayOutputStream()
+        def daos = new DataOutputStream(baos)
+        
+        daos.writeByte(Constants.COLLECTION_VERSION)
+        daos.writeShort(files.size())
+        author.write(daos)
+        daos.writeLong(timestamp)
+        def commentName = new Name(comment)
+        commentName.write(daos)
+        files.each { 
+            it.write(daos)
+        }
+        
+        daos.close()
+        baos.toByteArray()
+    }
+    
+    public void write(OutputStream os) {
+        if (payload == null) {
+            def baos = new ByteArrayOutputStream()
+            def daos = new DataOutputStream(baos)
+            
+            daos.write(signablePayload())
+            daos.write(sig)
+            
+            daos.close()
+            payload = baos.toByteArray()
+        }
+        os.write(payload)
+    }
+    
+    
+
+}

core/src/main/groovy/com/muwire/core/collections/FileCollectionItem.groovy

@@ -0,0 +1,77 @@
+package com.muwire.core.collections
+
+import com.muwire.core.Constants
+import com.muwire.core.InfoHash
+import com.muwire.core.Name
+
+class FileCollectionItem {
+    
+    private final InfoHash infoHash
+    private final String comment
+    private final File file
+    private volatile byte[] payload
+    private final List<String> pathElements = new ArrayList<>()
+
+    public FileCollectionItem(InfoHash infoHash, String comment, List<String> pathElements) {
+        this.infoHash = infoHash
+        this.comment = comment
+        this.pathElements = pathElements
+        
+        File f = null
+        pathElements.each { 
+            if (f == null) {
+                f = new File(it)
+                return
+            }
+            f = new File(f, it)
+        }
+        this.file = f
+    }
+    
+    public FileCollectionItem(InputStream is) {
+        DataInputStream dis = new DataInputStream(is)
+        byte version = dis.readByte()
+        if (version != Constants.COLLECTION_ENTRY_VERSION)
+            throw new InvalidCollectionException("unsupported entry version $version")
+        
+        byte [] hash = new byte[32]
+        dis.readFully(hash)
+        infoHash = new InfoHash(hash)
+        
+        int nPathElements = dis.readUnsignedByte()
+        File f = null
+        nPathElements.times { 
+            def element = new Name(dis)
+            pathElements.add(element.name)
+            if (f == null) {
+                f = new File(element.name)
+                return
+            }
+            f = new File(f, element.name)
+        }
+        file = f
+        
+        def commentName = new Name(dis)
+        comment = commentName.name
+    }
+    
+    void write(OutputStream os) {
+        if (payload == null) {
+            def baos = new ByteArrayOutputStream()
+            def daos = new DataOutputStream(baos)
+            
+            daos.writeByte(Constants.COLLECTION_ENTRY_VERSION)
+            daos.write(infoHash.getRoot())
+            daos.writeByte((byte) pathElements.size())
+            pathElements.each { 
+                def name = new Name(it)
+                name.write(daos)
+            }
+            def commentName = new Name(comment)
+            commentName.write(daos)
+            daos.close()
+            payload = baos.toByteArray()
+        }
+        os.write(payload)
+    }
+}

core/src/main/groovy/com/muwire/core/collections/InvalidCollectionException.groovy

@@ -0,0 +1,26 @@
+package com.muwire.core.collections
+
+class InvalidCollectionException extends Exception {
+
+    public InvalidCollectionException() {
+        super();
+    }
+
+    public InvalidCollectionException(String message, Throwable cause, boolean enableSuppression,
+            boolean writableStackTrace) {
+        super(message, cause, enableSuppression, writableStackTrace);
+    }
+
+    public InvalidCollectionException(String message, Throwable cause) {
+        super(message, cause);
+    }
+
+    public InvalidCollectionException(String message) {
+        super(message);
+    }
+
+    public InvalidCollectionException(Throwable cause) {
+        super(cause);
+    }
+
+}

core/src/main/java/com/muwire/core/Constants.java

@@ -8,6 +8,8 @@ public class Constants {
     public static final int MAX_NICKNAME_LENGTH = 30;
     public static final byte FILE_CERT_VERSION = (byte)2;
     public static final int CHAT_VERSION = 1;
+    public static final byte COLLECTION_VERSION = (byte)1;
+    public static final byte COLLECTION_ENTRY_VERSION = (byte)1;
     
     public static final SigType SIG_TYPE = SigType.EdDSA_SHA512_Ed25519;