1 files changed, 148 insertions, 0 deletions
diff --git a/src/eu/siacs/conversations/DownloadableFile.java b/src/eu/siacs/conversations/DownloadableFile.java
new file mode 100644
index 00000000..c8097df8
--- /dev/null
+++ b/src/eu/siacs/conversations/DownloadableFile.java
@@ -0,0 +1,148 @@
+package eu.siacs.conversations;
+
+import java.io.File;
+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.Key;
+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.utils.CryptoHelper;
+import android.util.Log;
+
+public class DownloadableFile extends File {
+
+	private static final long serialVersionUID = 2247012619505115863L;
+
+	private long expectedSize = 0;
+	private String sha1sum;
+	private Key aeskey;
+	
+	private byte[] iv = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
+			0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0xf };
+
+	public DownloadableFile(String path) {
+		super(path);
+	}
+
+	public long getSize() {
+		return super.length();
+	}
+
+	public long getExpectedSize() {
+		if (this.aeskey != null) {
+			return (this.expectedSize / 16 + 1) * 16;
+		} else {
+			return this.expectedSize;
+		}
+	}
+
+	public void setExpectedSize(long size) {
+		this.expectedSize = size;
+	}
+
+	public String getSha1Sum() {
+		return this.sha1sum;
+	}
+
+	public void setSha1Sum(String sum) {
+		this.sha1sum = sum;
+	}
+
+	public void setKey(byte[] key) {
+		if (key.length >= 32) {
+			byte[] secretKey = new byte[32];
+			System.arraycopy(key, 0, secretKey, 0, 32);
+			this.aeskey = new SecretKeySpec(secretKey, "AES");
+		} else if (key.length >= 16) {
+			byte[] secretKey = new byte[16];
+			System.arraycopy(key, 0, secretKey, 0, 16);
+			this.aeskey = new SecretKeySpec(secretKey, "AES");
+		} else {
+			Log.d(Config.LOGTAG, "weird key");
+		}
+		Log.d(Config.LOGTAG,
+				"using aes key "
+						+ CryptoHelper.bytesToHex(this.aeskey.getEncoded()));
+	}
+
+	public Key getKey() {
+		return this.aeskey;
+	}
+	
+	public InputStream createInputStream() {
+		if (this.getKey() == null) {
+			try {
+				return new FileInputStream(this);
+			} catch (FileNotFoundException e) {
+				return null;
+			}
+		} else {
+			try {
+				IvParameterSpec ips = new IvParameterSpec(iv);
+				Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
+				cipher.init(Cipher.ENCRYPT_MODE, this.getKey(), ips);
+				Log.d(Config.LOGTAG, "opening encrypted input stream");
+				return new CipherInputStream(new FileInputStream(this), cipher);
+			} catch (NoSuchAlgorithmException e) {
+				Log.d(Config.LOGTAG, "no such algo: " + e.getMessage());
+				return null;
+			} catch (NoSuchPaddingException e) {
+				Log.d(Config.LOGTAG, "no such padding: " + e.getMessage());
+				return null;
+			} catch (InvalidKeyException e) {
+				Log.d(Config.LOGTAG, "invalid key: " + e.getMessage());
+				return null;
+			} catch (InvalidAlgorithmParameterException e) {
+				Log.d(Config.LOGTAG, "invavid iv:" + e.getMessage());
+				return null;
+			} catch (FileNotFoundException e) {
+				return null;
+			}
+		}
+	}
+
+	public OutputStream createOutputStream() {
+		if (this.getKey() == null) {
+			try {
+				return new FileOutputStream(this);
+			} catch (FileNotFoundException e) {
+				return null;
+			}
+		} else {
+			try {
+				IvParameterSpec ips = new IvParameterSpec(iv);
+				Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
+				cipher.init(Cipher.DECRYPT_MODE, this.getKey(), ips);
+				Log.d(Config.LOGTAG, "opening encrypted output stream");
+				return new CipherOutputStream(new FileOutputStream(this),
+						cipher);
+			} catch (NoSuchAlgorithmException e) {
+				Log.d(Config.LOGTAG, "no such algo: " + e.getMessage());
+				return null;
+			} catch (NoSuchPaddingException e) {
+				Log.d(Config.LOGTAG, "no such padding: " + e.getMessage());
+				return null;
+			} catch (InvalidKeyException e) {
+				Log.d(Config.LOGTAG, "invalid key: " + e.getMessage());
+				return null;
+			} catch (InvalidAlgorithmParameterException e) {
+				Log.d(Config.LOGTAG, "invavid iv:" + e.getMessage());
+				return null;
+			} catch (FileNotFoundException e) {
+				return null;
+			}
+		}
+	}
+}