1 files changed, 85 insertions, 0 deletions
diff --git a/src/main/java/de/pixart/messenger/utils/BackupFileHeader.java b/src/main/java/de/pixart/messenger/utils/BackupFileHeader.java
new file mode 100644
index 000000000..204ec45eb
--- /dev/null
+++ b/src/main/java/de/pixart/messenger/utils/BackupFileHeader.java
@@ -0,0 +1,85 @@
+package de.pixart.messenger.utils;
+
+import java.io.DataInputStream;
+import java.io.DataOutputStream;
+import java.io.IOException;
+import java.util.Arrays;
+
+import rocks.xmpp.addr.Jid;
+
+public class BackupFileHeader {
+
+    private static final int VERSION = 1;
+
+    private String app;
+    private Jid jid;
+    private long timestamp;
+    private byte[] iv;
+    private byte[] salt;
+
+
+    @Override
+    public String toString() {
+        return "BackupFileHeader{" +
+                "app='" + app + '\'' +
+                ", jid=" + jid +
+                ", timestamp=" + timestamp +
+                ", iv=" + CryptoHelper.bytesToHex(iv) +
+                ", salt=" + CryptoHelper.bytesToHex(salt) +
+                '}';
+    }
+
+    public BackupFileHeader(String app, Jid jid, long timestamp, byte[] iv, byte[] salt) {
+        this.app = app;
+        this.jid = jid;
+        this.timestamp = timestamp;
+        this.iv = iv;
+        this.salt = salt;
+    }
+
+    public void write(DataOutputStream dataOutputStream) throws IOException {
+        dataOutputStream.writeInt(VERSION);
+        dataOutputStream.writeUTF(app);
+        dataOutputStream.writeUTF(jid.asBareJid().toEscapedString());
+        dataOutputStream.writeLong(timestamp);
+        dataOutputStream.write(iv);
+        dataOutputStream.write(salt);
+    }
+
+    public static BackupFileHeader read(DataInputStream inputStream) throws IOException {
+        final int version = inputStream.readInt();
+        if (version > VERSION) {
+            throw new IllegalArgumentException("Backup File version was " + version + " but app only supports up to version " + VERSION);
+        }
+        String app = inputStream.readUTF();
+        String jid = inputStream.readUTF();
+        long timestamp = inputStream.readLong();
+        byte[] iv = new byte[12];
+        inputStream.readFully(iv);
+        byte[] salt = new byte[16];
+        inputStream.readFully(salt);
+
+        return new BackupFileHeader(app, Jid.of(jid), timestamp, iv, salt);
+
+    }
+
+    public byte[] getSalt() {
+        return salt;
+    }
+
+    public byte[] getIv() {
+        return iv;
+    }
+
+    public Jid getJid() {
+        return jid;
+    }
+
+    public String getApp() {
+        return app;
+    }
+
+    public long getTimestamp() {
+        return timestamp;
+    }
+}
+\ No newline at end of file