Address out-of-bounds for array size with int wrap-around

Author: adamretter

src/main/java/org/apache/commons/codec/binary/Base16.java

@@ -220,7 +220,12 @@ void encode(final byte[] data, final int offset, final int length, final Context
             return;
         }
 
-        final byte[] buffer = ensureBufferSize(length * BYTES_PER_ENCODED_BLOCK, context);
+        final int size = length * BYTES_PER_ENCODED_BLOCK;
+        if (size < 0) {
+            throw new IllegalArgumentException("Input length exceeds maximum size for encoded data: " + length);
+        }
+
+        final byte[] buffer = ensureBufferSize(size, context);
 
         final int end = offset + length;
         for (int i = offset; i < end; i++) {

src/test/java/org/apache/commons/codec/binary/Base16Test.java

@@ -483,6 +483,7 @@ private String toString(final byte[] data) {
      *
      * @see <a href="https://issues.apache.org/jira/projects/CODEC/issues/CODEC-265">CODEC-265</a>
      */
+    @Test
     public void testCodec265_over() {
         // almost 1GiB file to encode: 2^29 bytes
         final int size1GiB = 1 << 29;
@@ -510,6 +511,12 @@ public void testCodec265_over() {
         assertEquals(expectedLength, encoded.length);
     }
 
+    @Test(expected = IllegalArgumentException.class)
+    public void checkEncodeLengthBounds() {
+        final Base16 base16 = new Base16();
+        base16.encode(new byte[10], 0, 1 << 30);
+    }
+
     @Test
     public void testIsInAlphabet() {
         // invalid bounds