1 files changed, 73 insertions, 0 deletions
diff --git a/src/main/java/eu/siacs/conversations/xmpp/jingle/JingleTransport.java b/src/main/java/eu/siacs/conversations/xmpp/jingle/JingleTransport.java
index e832d3f5..1219794f 100644
--- a/src/main/java/eu/siacs/conversations/xmpp/jingle/JingleTransport.java
+++ b/src/main/java/eu/siacs/conversations/xmpp/jingle/JingleTransport.java
@@ -1,5 +1,24 @@
 package eu.siacs.conversations.xmpp.jingle;
 
+import android.util.Log;
+
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.security.InvalidAlgorithmParameterException;
+import java.security.InvalidKeyException;
+import java.security.NoSuchAlgorithmException;
+
+import javax.crypto.Cipher;
+import javax.crypto.CipherInputStream;
+import javax.crypto.CipherOutputStream;
+import javax.crypto.NoSuchPaddingException;
+import javax.crypto.spec.IvParameterSpec;
+import javax.crypto.spec.SecretKeySpec;
+
+import eu.siacs.conversations.Config;
 import eu.siacs.conversations.entities.DownloadableFile;
 
 public abstract class JingleTransport {
@@ -12,4 +31,58 @@ public abstract class JingleTransport {
 			final OnFileTransmissionStatusChanged callback);
 
 	public abstract void disconnect();
+
+	protected InputStream createInputStream(DownloadableFile file) {
+		FileInputStream is;
+		try {
+			is = new FileInputStream(file);
+			if (file.getKey() == null) {
+				return is;
+			}
+		} catch (FileNotFoundException e) {
+			return null;
+		}
+		try {
+			IvParameterSpec ips = new IvParameterSpec(file.getIv());
+			Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
+			cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(file.getKey(), "AES"), ips);
+			Log.d(Config.LOGTAG, "opening encrypted input stream");
+			return new CipherInputStream(is, cipher);
+		} catch (InvalidKeyException e) {
+			return null;
+		} catch (NoSuchAlgorithmException e) {
+			return null;
+		} catch (NoSuchPaddingException e) {
+			return null;
+		} catch (InvalidAlgorithmParameterException e) {
+			return null;
+		}
+	}
+
+	protected OutputStream createOutputStream(DownloadableFile file) {
+		FileOutputStream os;
+		try {
+			os = new FileOutputStream(file);
+			if (file.getKey() == null) {
+				return os;
+			}
+		} catch (FileNotFoundException e) {
+			return null;
+		}
+		try {
+			IvParameterSpec ips = new IvParameterSpec(file.getIv());
+			Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
+			cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(file.getKey(), "AES"), ips);
+			Log.d(Config.LOGTAG, "opening encrypted output stream");
+			return new CipherOutputStream(os, cipher);
+		} catch (InvalidKeyException e) {
+			return null;
+		} catch (NoSuchAlgorithmException e) {
+			return null;
+		} catch (NoSuchPaddingException e) {
+			return null;
+		} catch (InvalidAlgorithmParameterException e) {
+			return null;
+		}
+	}
 }