mirror of
https://github.com/signalapp/Signal-Android.git
synced 2026-02-22 18:55:12 +00:00
Move API around a little, eliminate TransportDetails interface.
This commit is contained in:
Moxie Marlinspike
@@ -0,0 +1,211 @@
|
||||
/**
|
||||
* Copyright (C) 2013 Open Whisper Systems
|
||||
*
|
||||
* This program is free software: you can redistribute it and/or modify
|
||||
* it under the terms of the GNU General Public License as published by
|
||||
* the Free Software Foundation, either version 3 of the License, or
|
||||
* (at your option) any later version.
|
||||
*
|
||||
* This program is distributed in the hope that it will be useful,
|
||||
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
* GNU General Public License for more details.
|
||||
*
|
||||
* You should have received a copy of the GNU General Public License
|
||||
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
||||
*/
|
||||
package org.whispersystems.textsecure.api.crypto;
|
||||
|
||||
import android.util.Log;
|
||||
|
||||
import org.whispersystems.libaxolotl.InvalidMacException;
|
||||
import org.whispersystems.libaxolotl.InvalidMessageException;
|
||||
import org.whispersystems.textsecure.util.Util;
|
||||
|
||||
import java.io.File;
|
||||
import java.io.FileInputStream;
|
||||
import java.io.FileNotFoundException;
|
||||
import java.io.IOException;
|
||||
import java.security.InvalidAlgorithmParameterException;
|
||||
import java.security.InvalidKeyException;
|
||||
import java.security.NoSuchAlgorithmException;
|
||||
import java.util.Arrays;
|
||||
|
||||
import javax.crypto.BadPaddingException;
|
||||
import javax.crypto.Cipher;
|
||||
import javax.crypto.IllegalBlockSizeException;
|
||||
import javax.crypto.Mac;
|
||||
import javax.crypto.NoSuchPaddingException;
|
||||
import javax.crypto.ShortBufferException;
|
||||
import javax.crypto.spec.IvParameterSpec;
|
||||
import javax.crypto.spec.SecretKeySpec;
|
||||
|
||||
/**
|
||||
* Class for streaming an encrypted push attachment off disk.
|
||||
*
|
||||
* @author Moxie Marlinspike
|
||||
*/
|
||||
|
||||
public class AttachmentCipherInputStream extends FileInputStream {
|
||||
|
||||
private static final int BLOCK_SIZE = 16;
|
||||
private static final int CIPHER_KEY_SIZE = 32;
|
||||
private static final int MAC_KEY_SIZE = 32;
|
||||
|
||||
private Cipher cipher;
|
||||
private boolean done;
|
||||
private long totalDataSize;
|
||||
private long totalRead;
|
||||
private byte[] overflowBuffer;
|
||||
|
||||
public AttachmentCipherInputStream(File file, byte[] combinedKeyMaterial)
|
||||
throws IOException, InvalidMessageException
|
||||
{
|
||||
super(file);
|
||||
|
||||
try {
|
||||
byte[][] parts = Util.split(combinedKeyMaterial, CIPHER_KEY_SIZE, MAC_KEY_SIZE);
|
||||
Mac mac = Mac.getInstance("HmacSHA256");
|
||||
|
||||
mac.init(new SecretKeySpec(parts[1], "HmacSHA256"));
|
||||
|
||||
if (file.length() <= BLOCK_SIZE + mac.getMacLength()) {
|
||||
throw new InvalidMessageException("Message shorter than crypto overhead!");
|
||||
}
|
||||
|
||||
verifyMac(file, mac);
|
||||
|
||||
byte[] iv = new byte[BLOCK_SIZE];
|
||||
readFully(iv);
|
||||
|
||||
this.cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
|
||||
this.cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(parts[0], "AES"), new IvParameterSpec(iv));
|
||||
|
||||
this.done = false;
|
||||
this.totalRead = 0;
|
||||
this.totalDataSize = file.length() - cipher.getBlockSize() - mac.getMacLength();
|
||||
} catch (NoSuchAlgorithmException | InvalidKeyException | NoSuchPaddingException | InvalidAlgorithmParameterException e) {
|
||||
throw new AssertionError(e);
|
||||
} catch (InvalidMacException e) {
|
||||
throw new InvalidMessageException(e);
|
||||
}
|
||||
}
|
||||
|
||||
@Override
|
||||
public int read(byte[] buffer) throws IOException {
|
||||
return read(buffer, 0, buffer.length);
|
||||
}
|
||||
|
||||
@Override
|
||||
public int read(byte[] buffer, int offset, int length) throws IOException {
|
||||
if (totalRead != totalDataSize) return readIncremental(buffer, offset, length);
|
||||
else if (!done) return readFinal(buffer, offset, length);
|
||||
else return -1;
|
||||
}
|
||||
|
||||
private int readFinal(byte[] buffer, int offset, int length) throws IOException {
|
||||
try {
|
||||
int flourish = cipher.doFinal(buffer, offset);
|
||||
|
||||
done = true;
|
||||
return flourish;
|
||||
} catch (IllegalBlockSizeException e) {
|
||||
Log.w("EncryptingPartInputStream", e);
|
||||
throw new IOException("Illegal block size exception!");
|
||||
} catch (ShortBufferException e) {
|
||||
Log.w("EncryptingPartInputStream", e);
|
||||
throw new IOException("Short buffer exception!");
|
||||
} catch (BadPaddingException e) {
|
||||
Log.w("EncryptingPartInputStream", e);
|
||||
throw new IOException("Bad padding exception!");
|
||||
}
|
||||
}
|
||||
|
||||
private int readIncremental(byte[] buffer, int offset, int length) throws IOException {
|
||||
int readLength = 0;
|
||||
if (null != overflowBuffer) {
|
||||
if (overflowBuffer.length > length) {
|
||||
System.arraycopy(overflowBuffer, 0, buffer, offset, length);
|
||||
overflowBuffer = Arrays.copyOfRange(overflowBuffer, length, overflowBuffer.length);
|
||||
return length;
|
||||
} else if (overflowBuffer.length == length) {
|
||||
System.arraycopy(overflowBuffer, 0, buffer, offset, length);
|
||||
overflowBuffer = null;
|
||||
return length;
|
||||
} else {
|
||||
System.arraycopy(overflowBuffer, 0, buffer, offset, overflowBuffer.length);
|
||||
readLength += overflowBuffer.length;
|
||||
offset += readLength;
|
||||
length -= readLength;
|
||||
overflowBuffer = null;
|
||||
}
|
||||
}
|
||||
|
||||
if (length + totalRead > totalDataSize)
|
||||
length = (int)(totalDataSize - totalRead);
|
||||
|
||||
byte[] internalBuffer = new byte[length];
|
||||
int read = super.read(internalBuffer, 0, internalBuffer.length <= cipher.getBlockSize() ? internalBuffer.length : internalBuffer.length - cipher.getBlockSize());
|
||||
totalRead += read;
|
||||
|
||||
try {
|
||||
int outputLen = cipher.getOutputSize(read);
|
||||
|
||||
if (outputLen <= length) {
|
||||
readLength += cipher.update(internalBuffer, 0, read, buffer, offset);
|
||||
return readLength;
|
||||
}
|
||||
|
||||
byte[] transientBuffer = new byte[outputLen];
|
||||
outputLen = cipher.update(internalBuffer, 0, read, transientBuffer, 0);
|
||||
if (outputLen <= length) {
|
||||
System.arraycopy(transientBuffer, 0, buffer, offset, outputLen);
|
||||
readLength += outputLen;
|
||||
} else {
|
||||
System.arraycopy(transientBuffer, 0, buffer, offset, length);
|
||||
overflowBuffer = Arrays.copyOfRange(transientBuffer, length, outputLen);
|
||||
readLength += length;
|
||||
}
|
||||
return readLength;
|
||||
} catch (ShortBufferException e) {
|
||||
throw new AssertionError(e);
|
||||
}
|
||||
}
|
||||
|
||||
private void verifyMac(File file, Mac mac) throws FileNotFoundException, InvalidMacException {
|
||||
try {
|
||||
FileInputStream fin = new FileInputStream(file);
|
||||
int remainingData = (int) file.length() - mac.getMacLength();
|
||||
byte[] buffer = new byte[4096];
|
||||
|
||||
while (remainingData > 0) {
|
||||
int read = fin.read(buffer, 0, Math.min(buffer.length, remainingData));
|
||||
mac.update(buffer, 0, read);
|
||||
remainingData -= read;
|
||||
}
|
||||
|
||||
byte[] ourMac = mac.doFinal();
|
||||
byte[] theirMac = new byte[mac.getMacLength()];
|
||||
Util.readFully(fin, theirMac);
|
||||
|
||||
if (!Arrays.equals(ourMac, theirMac)) {
|
||||
throw new InvalidMacException("MAC doesn't match!");
|
||||
}
|
||||
} catch (IOException e1) {
|
||||
throw new InvalidMacException(e1);
|
||||
}
|
||||
}
|
||||
|
||||
private void readFully(byte[] buffer) throws IOException {
|
||||
int offset = 0;
|
||||
|
||||
for (;;) {
|
||||
int read = super.read(buffer, offset, buffer.length - offset);
|
||||
|
||||
if (read + offset < buffer.length) offset += read;
|
||||
else return;
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
}
|
||||
Reference in New Issue
Block a user