diff -r f67951f722a4 src/java.base/share/classes/java/util/Base64.java
--- a/src/java.base/share/classes/java/util/Base64.java	Wed Feb 26 21:24:02 2020 +0100
+++ b/src/java.base/share/classes/java/util/Base64.java	Thu Feb 27 02:30:49 2020 +0100
@@ -667,6 +667,37 @@
                 throw iae;
             }
         }
+        /**
+         * Decodes a Base64 encoded String into a newly-allocated byte array
+         * using the {@link Base64} encoding scheme.
+         *
+         * <p> If the input byte array is not in valid Base64 encoding scheme
+         * then some bytes may have been written to the output byte array before
+         * IllegalargumentException is thrown.
+         *
+         * @param   src
+         *          the byte array to decode
+         * @param   srcFrom
+         *          the index in the {@code src} to start decoding from
+         * @param   srcTo
+         *          the index in the {@code src} to decoding to, exclusive
+         *
+         * @return  The number of bytes written to the output byte array
+         *
+         * @throws  IllegalArgumentException
+         *          if {@code src} is not in valid Base64 scheme
+         * @throws  IndexOutOfBoundsException if the sub-range {@code srcFrom}
+         *          to {@code srcTo} is out of bounds.
+         */
+        public byte[] decode(byte[] src, int srcFrom, int srcTo) {
+            Objects.checkFromToIndex(srcFrom, srcTo, src.length);
+            byte[] dst = new byte[decodedOutLength(src, srcFrom, srcTo)];
+            int ret = decode0(src, srcFrom, srcTo, dst);
+            if (ret != dst.length) {
+                dst = Arrays.copyOf(dst, ret);
+            }
+            return dst;
+        }
 
         /**
          * Returns an input stream for decoding {@link Base64} encoded byte stream.