Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 123 insertions, 0 deletions

diff --git a/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/upstream/crypto/AesFlushingCipher.java b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/upstream/crypto/AesFlushingCipher.java
new file mode 100644
index 0000000000..985a6dcf24
--- /dev/null
+++ b/mobile/android/exoplayer2/src/main/java/org/mozilla/thirdparty/com/google/android/exoplayer2/upstream/crypto/AesFlushingCipher.java
@@ -0,0 +1,123 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.mozilla.thirdparty.com.google.android.exoplayer2.upstream.crypto;
+
+import org.mozilla.thirdparty.com.google.android.exoplayer2.util.Assertions;
+import org.mozilla.thirdparty.com.google.android.exoplayer2.util.Util;
+import java.nio.ByteBuffer;
+import java.security.InvalidAlgorithmParameterException;
+import java.security.InvalidKeyException;
+import java.security.NoSuchAlgorithmException;
+import javax.crypto.Cipher;
+import javax.crypto.NoSuchPaddingException;
+import javax.crypto.ShortBufferException;
+import javax.crypto.spec.IvParameterSpec;
+import javax.crypto.spec.SecretKeySpec;
+
+/**
+ * A flushing variant of a AES/CTR/NoPadding {@link Cipher}.
+ *
+ * Unlike a regular {@link Cipher}, the update methods of this class are guaranteed to process all
+ * of the bytes input (and hence output the same number of bytes).
+ */
+public final class AesFlushingCipher {
+
+  private final Cipher cipher;
+  private final int blockSize;
+  private final byte[] zerosBlock;
+  private final byte[] flushedBlock;
+
+  private int pendingXorBytes;
+
+  public AesFlushingCipher(int mode, byte[] secretKey, long nonce, long offset) {
+    try {
+      cipher = Cipher.getInstance("AES/CTR/NoPadding");
+      blockSize = cipher.getBlockSize();
+      zerosBlock = new byte[blockSize];
+      flushedBlock = new byte[blockSize];
+      long counter = offset / blockSize;
+      int startPadding = (int) (offset % blockSize);
+      cipher.init(
+          mode,
+          new SecretKeySpec(secretKey, Util.splitAtFirst(cipher.getAlgorithm(), "/")[0]),
+          new IvParameterSpec(getInitializationVector(nonce, counter)));
+      if (startPadding != 0) {
+        updateInPlace(new byte[startPadding], 0, startPadding);
+      }
+    } catch (NoSuchAlgorithmException | NoSuchPaddingException | InvalidKeyException
+        | InvalidAlgorithmParameterException e) {
+      // Should never happen.
+      throw new RuntimeException(e);
+    }
+  }
+
+  public void updateInPlace(byte[] data, int offset, int length) {
+    update(data, offset, length, data, offset);
+  }
+
+  public void update(byte[] in, int inOffset, int length, byte[] out, int outOffset) {
+    // If we previously flushed the cipher by inputting zeros up to a block boundary, then we need
+    // to manually transform the data that actually ended the block. See the comment below for more
+    // details.
+    while (pendingXorBytes > 0) {
+      out[outOffset] = (byte) (in[inOffset] ^ flushedBlock[blockSize - pendingXorBytes]);
+      outOffset++;
+      inOffset++;
+      pendingXorBytes--;
+      length--;
+      if (length == 0) {
+        return;
+      }
+    }
+
+    // Do the bulk of the update.
+    int written = nonFlushingUpdate(in, inOffset, length, out, outOffset);
+    if (length == written) {
+      return;
+    }
+
+    // We need to finish the block to flush out the remaining bytes. We do so by inputting zeros,
+    // so that the corresponding bytes output by the cipher are those that would have been XORed
+    // against the real end-of-block data to transform it. We store these bytes so that we can
+    // perform the transformation manually in the case of a subsequent call to this method with
+    // the real data.
+    int bytesToFlush = length - written;
+    Assertions.checkState(bytesToFlush < blockSize);
+    outOffset += written;
+    pendingXorBytes = blockSize - bytesToFlush;
+    written = nonFlushingUpdate(zerosBlock, 0, pendingXorBytes, flushedBlock, 0);
+    Assertions.checkState(written == blockSize);
+    // The first part of xorBytes contains the flushed data, which we copy out. The remainder
+    // contains the bytes that will be needed for manual transformation in a subsequent call.
+    for (int i = 0; i < bytesToFlush; i++) {
+      out[outOffset++] = flushedBlock[i];
+    }
+  }
+
+  private int nonFlushingUpdate(byte[] in, int inOffset, int length, byte[] out, int outOffset) {
+    try {
+      return cipher.update(in, inOffset, length, out, outOffset);
+    } catch (ShortBufferException e) {
+      // Should never happen.
+      throw new RuntimeException(e);
+    }
+  }
+
+  private byte[] getInitializationVector(long nonce, long counter) {
+    return ByteBuffer.allocate(16).putLong(nonce).putLong(counter).array();
+  }
+
+}