Legacy Bridge report

--- legacy/Base64.java
+++ bob/Base64.java
@@ -1,18 +1,18 @@
 /*
  * Copyright 2001-2004 The Apache Software Foundation.
- * 
+ *
  * 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.apache.commons.codec.binary;
 
@@ -23,10 +23,10 @@
 
 /**
  * Provides Base64 encoding and decoding as defined by RFC 2045.
- * 
- * <p>This class implements section <cite>6.8. Base64 Content-Transfer-Encoding</cite> 
- * from RFC 2045 <cite>Multipurpose Internet Mail Extensions (MIME) Part One: 
- * Format of Internet Message Bodies</cite> by Freed and Borenstein.</p> 
+ *
+ * <p>This class implements section <cite>6.8. Base64 Content-Transfer-Encoding</cite>
+ * from RFC 2045 <cite>Multipurpose Internet Mail Extensions (MIME) Part One:
+ * Format of Internet Message Bodies</cite> by Freed and Borenstein.</p>
  *
  * @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045</a>
  * @author Apache Software Foundation
@@ -37,67 +37,48 @@
 
     /**
      * Chunk size per RFC 2045 section 6.8.
-     * 
-     * <p>The {@value} character limit does not count the trailing CRLF, but counts 
+     *
+     * <p>The {@value} character limit does not count the trailing CRLF, but counts
      * all other characters, including any equal signs.</p>
-     * 
+     *
      * @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045 section 6.8</a>
      */
     static final int CHUNK_SIZE = 76;
 
     /**
      * Chunk separator per RFC 2045 section 2.1.
-     * 
+     *
      * @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045 section 2.1</a>
      */
-    static final byte[] CHUNK_SEPARATOR = "\r\n".getBytes();
-
-    /**
-     * The base length.
-     */
+    static final byte[] CHUNK_SEPARATOR = "\r\n".getBytes(java.nio.charset.StandardCharsets.US_ASCII);
+
+    /** The base length. */
     static final int BASELENGTH = 255;
 
-    /**
-     * Lookup length.
-     */
+    /** Lookup length. */
     static final int LOOKUPLENGTH = 64;
 
-    /**
-     * Used to calculate the number of bits in a byte.
-     */
+    /** Used to calculate the number of bits in a byte. */
     static final int EIGHTBIT = 8;
 
-    /**
-     * Used when encoding something which has fewer than 24 bits.
-     */
+    /** Used when encoding something which has fewer than 24 bits. */
     static final int SIXTEENBIT = 16;
 
-    /**
-     * Used to determine how many bits data contains.
-     */
+    /** Used to determine how many bits data contains. */
     static final int TWENTYFOURBITGROUP = 24;
 
-    /**
-     * Used to get the number of Quadruples.
-     */
+    /** Used to get the number of Quadruples. */
     static final int FOURBYTE = 4;
 
-    /**
-     * Used to test the sign of a byte.
-     */
+    /** Used to test the sign of a byte. */
     static final int SIGN = -128;
-    
-    /**
-     * Byte used to pad output.
-     */
+
+    /** Byte used to pad output. */
     static final byte PAD = (byte) '=';
 
-    // Create arrays to hold the base64 characters and a 
-    // lookup for base64 chars
-    private static byte[] base64Alphabet = new byte[BASELENGTH];
-    private static byte[] lookUpBase64Alphabet = new byte[LOOKUPLENGTH];
-
-    // Populating the lookup and character arrays
+    private static final byte[] base64Alphabet = new byte[BASELENGTH];
+    private static final byte[] lookUpBase64Alphabet = new byte[LOOKUPLENGTH];
+
     static {
         for (int i = 0; i < BASELENGTH; i++) {
             base64Alphabet[i] = (byte) -1;
@@ -111,22 +92,18 @@
         for (int i = '9'; i >= '0'; i--) {
             base64Alphabet[i] = (byte) (i - '0' + 52);
         }
-
         base64Alphabet['+'] = 62;
         base64Alphabet['/'] = 63;
 
         for (int i = 0; i <= 25; i++) {
             lookUpBase64Alphabet[i] = (byte) ('A' + i);
         }
-
         for (int i = 26, j = 0; i <= 51; i++, j++) {
             lookUpBase64Alphabet[i] = (byte) ('a' + j);
         }
-
         for (int i = 52, j = 0; i <= 61; i++, j++) {
             lookUpBase64Alphabet[i] = (byte) ('0' + j);
         }
-
         lookUpBase64Alphabet[62] = (byte) '+';
         lookUpBase64Alphabet[63] = (byte) '/';
     }
@@ -134,29 +111,22 @@
     private static boolean isBase64(byte octect) {
         if (octect == PAD) {
             return true;
-        } else if (base64Alphabet[octect] == -1) {
-            return false;
-        } else {
-            return true;
-        }
-    }
-
-    /**
-     * Tests a given byte array to see if it contains
-     * only valid characters within the Base64 alphabet.
+        }
+        return base64Alphabet[octect] != -1;
+    }
+
+    /**
+     * Tests a given byte array to see if it contains only valid characters
+     * within the Base64 alphabet.
      *
      * @param arrayOctect byte array to test
-     * @return true if all bytes are valid characters in the Base64
-     *         alphabet or if the byte array is empty; false, otherwise
+     * @return true if all bytes are valid characters in the Base64 alphabet or
+     *         if the byte array is empty; false, otherwise
      */
     public static boolean isArrayByteBase64(byte[] arrayOctect) {
-
         arrayOctect = discardWhitespace(arrayOctect);
-
         int length = arrayOctect.length;
         if (length == 0) {
-            // shouldn't a 0 length array be valid base64 data?
-            // return false;
             return true;
         }
         for (int i = 0; i < length; i++) {
@@ -168,8 +138,7 @@
     }
 
     /**
-     * Encodes binary data using the base64 algorithm but
-     * does not chunk the output.
+     * Encodes binary data using the base64 algorithm but does not chunk the output.
      *
      * @param binaryData binary data to encode
      * @return Base64 characters
@@ -179,8 +148,8 @@
     }
 
     /**
-     * Encodes binary data using the base64 algorithm and chunks
-     * the encoded output into 76 character blocks
+     * Encodes binary data using the base64 algorithm and chunks the encoded output
+     * into 76 character blocks.
      *
      * @param binaryData binary data to encode
      * @return Base64 characters chunked in 76 character blocks
@@ -189,174 +158,142 @@
         return encodeBase64(binaryData, true);
     }
 
-
-    /**
-     * Decodes an Object using the base64 algorithm.  This method
-     * is provided in order to satisfy the requirements of the
-     * Decoder interface, and will throw a DecoderException if the
-     * supplied object is not of type byte[].
+    /**
+     * Decodes an Object using the base64 algorithm. This method is provided in order
+     * to satisfy the requirements of the Decoder interface, and will throw a
+     * DecoderException if the supplied object is not of type byte[].
      *
      * @param pObject Object to decode
-     * @return An object (of type byte[]) containing the 
-     *         binary data which corresponds to the byte[] supplied.
-     * @throws DecoderException if the parameter supplied is not
-     *                          of type byte[]
-     */
+     * @return An object (of type byte[]) containing the binary data which corresponds
+     *         to the byte[] supplied.
+     * @throws DecoderException if the parameter supplied is not of type byte[]
+     */
+    @Override
     public Object decode(Object pObject) throws DecoderException {
         if (!(pObject instanceof byte[])) {
-            throw new DecoderException("Parameter supplied to Base64 decode is not a byte[]");
+            throw new DecoderException(
+                    "Parameter supplied to Base64 decode is not a byte[]");
         }
         return decode((byte[]) pObject);
     }
 
     /**
-     * Decodes a byte[] containing containing
-     * characters in the Base64 alphabet.
+     * Decodes a byte[] containing characters in the Base64 alphabet.
      *
      * @param pArray A byte array containing Base64 character data
      * @return a byte array containing binary data
      */
+    @Override
     public byte[] decode(byte[] pArray) {
         return decodeBase64(pArray);
     }
 
     /**
-     * Encodes binary data using the base64 algorithm, optionally
-     * chunking the output into 76 character blocks.
-     *
-     * @param binaryData Array containing binary data to encode.
-     * @param isChunked if isChunked is true this encoder will chunk
-     *                  the base64 output into 76 character blocks
+     * Encodes binary data using the base64 algorithm, optionally chunking the output
+     * into 76 character blocks.
+     *
+     * @param binaryData  Array containing binary data to encode.
+     * @param isChunked   if isChunked is true this encoder will chunk the base64
+     *                    output into 76 character blocks
      * @return Base64-encoded data.
      */
     public static byte[] encodeBase64(byte[] binaryData, boolean isChunked) {
         int lengthDataBits = binaryData.length * EIGHTBIT;
         int fewerThan24bits = lengthDataBits % TWENTYFOURBITGROUP;
         int numberTriplets = lengthDataBits / TWENTYFOURBITGROUP;
-        byte encodedData[] = null;
-        int encodedDataLength = 0;
+        int encodedDataLength;
         int nbrChunks = 0;
 
         if (fewerThan24bits != 0) {
-            //data not divisible by 24 bit
             encodedDataLength = (numberTriplets + 1) * 4;
         } else {
-            // 16 or 8 bit
             encodedDataLength = numberTriplets * 4;
         }
 
-        // If the output is to be "chunked" into 76 character sections, 
-        // for compliance with RFC 2045 MIME, then it is important to 
-        // allow for extra length to account for the separator(s)
         if (isChunked) {
-
-            nbrChunks =
-                (CHUNK_SEPARATOR.length == 0 ? 0 : (int) Math.ceil((float) encodedDataLength / CHUNK_SIZE));
+            nbrChunks = (CHUNK_SEPARATOR.length == 0)
+                    ? 0
+                    : (int) Math.ceil((float) encodedDataLength / CHUNK_SIZE);
             encodedDataLength += nbrChunks * CHUNK_SEPARATOR.length;
         }
 
-        encodedData = new byte[encodedDataLength];
-
-        byte k = 0, l = 0, b1 = 0, b2 = 0, b3 = 0;
-
+        byte[] encodedData = new byte[encodedDataLength];
+
+        byte k, l, b1, b2, b3;
         int encodedIndex = 0;
-        int dataIndex = 0;
-        int i = 0;
+        int dataIndex;
+        int i;
         int nextSeparatorIndex = CHUNK_SIZE;
         int chunksSoFar = 0;
 
-        //log.debug("number of triplets = " + numberTriplets);
         for (i = 0; i < numberTriplets; i++) {
             dataIndex = i * 3;
             b1 = binaryData[dataIndex];
             b2 = binaryData[dataIndex + 1];
             b3 = binaryData[dataIndex + 2];
 
-            //log.debug("b1= " + b1 +", b2= " + b2 + ", b3= " + b3);
-
             l = (byte) (b2 & 0x0f);
             k = (byte) (b1 & 0x03);
 
-            byte val1 =
-                ((b1 & SIGN) == 0) ? (byte) (b1 >> 2) : (byte) ((b1) >> 2 ^ 0xc0);
-            byte val2 =
-                ((b2 & SIGN) == 0) ? (byte) (b2 >> 4) : (byte) ((b2) >> 4 ^ 0xf0);
-            byte val3 =
-                ((b3 & SIGN) == 0) ? (byte) (b3 >> 6) : (byte) ((b3) >> 6 ^ 0xfc);
-
-            encodedData[encodedIndex] = lookUpBase64Alphabet[val1];
-            //log.debug( "val2 = " + val2 );
-            //log.debug( "k4   = " + (k<<4) );
-            //log.debug(  "vak  = " + (val2 | (k<<4)) );
-            encodedData[encodedIndex + 1] =
-                lookUpBase64Alphabet[val2 | (k << 4)];
-            encodedData[encodedIndex + 2] =
-                lookUpBase64Alphabet[(l << 2) | val3];
+            byte val1 = ((b1 & SIGN) == 0)
+                    ? (byte) (b1 >> 2) : (byte) ((b1) >> 2 ^ 0xc0);
+            byte val2 = ((b2 & SIGN) == 0)
+                    ? (byte) (b2 >> 4) : (byte) ((b2) >> 4 ^ 0xf0);
+            byte val3 = ((b3 & SIGN) == 0)
+                    ? (byte) (b3 >> 6) : (byte) ((b3) >> 6 ^ 0xfc);
+
+            encodedData[encodedIndex]     = lookUpBase64Alphabet[val1];
+            encodedData[encodedIndex + 1] = lookUpBase64Alphabet[val2 | (k << 4)];
+            encodedData[encodedIndex + 2] = lookUpBase64Alphabet[(l << 2) | val3];
             encodedData[encodedIndex + 3] = lookUpBase64Alphabet[b3 & 0x3f];
-
             encodedIndex += 4;
 
-            // If we are chunking, let's put a chunk separator down.
             if (isChunked) {
-                // this assumes that CHUNK_SIZE % 4 == 0
                 if (encodedIndex == nextSeparatorIndex) {
                     System.arraycopy(
-                        CHUNK_SEPARATOR,
-                        0,
-                        encodedData,
-                        encodedIndex,
-                        CHUNK_SEPARATOR.length);
+                            CHUNK_SEPARATOR, 0,
+                            encodedData, encodedIndex,
+                            CHUNK_SEPARATOR.length);
                     chunksSoFar++;
-                    nextSeparatorIndex =
-                        (CHUNK_SIZE * (chunksSoFar + 1)) + 
-                        (chunksSoFar * CHUNK_SEPARATOR.length);
+                    nextSeparatorIndex = (CHUNK_SIZE * (chunksSoFar + 1))
+                            + (chunksSoFar * CHUNK_SEPARATOR.length);
                     encodedIndex += CHUNK_SEPARATOR.length;
                 }
             }
         }
 
-        // form integral number of 6-bit groups
         dataIndex = i * 3;
 
         if (fewerThan24bits == EIGHTBIT) {
             b1 = binaryData[dataIndex];
             k = (byte) (b1 & 0x03);
-            //log.debug("b1=" + b1);
-            //log.debug("b1<<2 = " + (b1>>2) );
-            byte val1 =
-                ((b1 & SIGN) == 0) ? (byte) (b1 >> 2) : (byte) ((b1) >> 2 ^ 0xc0);
-            encodedData[encodedIndex] = lookUpBase64Alphabet[val1];
+            byte val1 = ((b1 & SIGN) == 0)
+                    ? (byte) (b1 >> 2) : (byte) ((b1) >> 2 ^ 0xc0);
+            encodedData[encodedIndex]     = lookUpBase64Alphabet[val1];
             encodedData[encodedIndex + 1] = lookUpBase64Alphabet[k << 4];
             encodedData[encodedIndex + 2] = PAD;
             encodedData[encodedIndex + 3] = PAD;
         } else if (fewerThan24bits == SIXTEENBIT) {
-
             b1 = binaryData[dataIndex];
             b2 = binaryData[dataIndex + 1];
             l = (byte) (b2 & 0x0f);
             k = (byte) (b1 & 0x03);
-
-            byte val1 =
-                ((b1 & SIGN) == 0) ? (byte) (b1 >> 2) : (byte) ((b1) >> 2 ^ 0xc0);
-            byte val2 =
-                ((b2 & SIGN) == 0) ? (byte) (b2 >> 4) : (byte) ((b2) >> 4 ^ 0xf0);
-
-            encodedData[encodedIndex] = lookUpBase64Alphabet[val1];
-            encodedData[encodedIndex + 1] =
-                lookUpBase64Alphabet[val2 | (k << 4)];
+            byte val1 = ((b1 & SIGN) == 0)
+                    ? (byte) (b1 >> 2) : (byte) ((b1) >> 2 ^ 0xc0);
+            byte val2 = ((b2 & SIGN) == 0)
+                    ? (byte) (b2 >> 4) : (byte) ((b2) >> 4 ^ 0xf0);
+            encodedData[encodedIndex]     = lookUpBase64Alphabet[val1];
+            encodedData[encodedIndex + 1] = lookUpBase64Alphabet[val2 | (k << 4)];
             encodedData[encodedIndex + 2] = lookUpBase64Alphabet[l << 2];
             encodedData[encodedIndex + 3] = PAD;
         }
 
         if (isChunked) {
-            // we also add a separator to the end of the final chunk.
             if (chunksSoFar < nbrChunks) {
                 System.arraycopy(
-                    CHUNK_SEPARATOR,
-                    0,
-                    encodedData,
-                    encodedDataLength - CHUNK_SEPARATOR.length,
-                    CHUNK_SEPARATOR.length);
+                        CHUNK_SEPARATOR, 0,
+                        encodedData, encodedDataLength - CHUNK_SEPARATOR.length,
+                        CHUNK_SEPARATOR.length);
             }
         }
 
@@ -364,32 +301,26 @@
     }
 
     /**
-     * Decodes Base64 data into octects
+     * Decodes Base64 data into octets.
      *
      * @param base64Data Byte array containing Base64 data
      * @return Array containing decoded data.
      */
     public static byte[] decodeBase64(byte[] base64Data) {
-        // RFC 2045 requires that we discard ALL non-Base64 characters
         base64Data = discardNonBase64(base64Data);
 
-        // handle the edge case, so we don't have to worry about it later
         if (base64Data.length == 0) {
             return new byte[0];
         }
 
         int numberQuadruple = base64Data.length / FOURBYTE;
-        byte decodedData[] = null;
-        byte b1 = 0, b2 = 0, b3 = 0, b4 = 0, marker0 = 0, marker1 = 0;
-
-        // Throw away anything not in base64Data
+        byte[] decodedData;
+        byte b1, b2, b3, b4, marker0, marker1;
 
         int encodedIndex = 0;
-        int dataIndex = 0;
+        int dataIndex;
         {
-            // this sizes the output array properly - rlw
             int lastData = base64Data.length;
-            // ignore the '=' padding
             while (base64Data[lastData - 1] == PAD) {
                 if (--lastData == 0) {
                     return new byte[0];
@@ -397,128 +328,113 @@
             }
             decodedData = new byte[lastData - numberQuadruple];
         }
-        
+
         for (int i = 0; i < numberQuadruple; i++) {
             dataIndex = i * 4;
             marker0 = base64Data[dataIndex + 2];
             marker1 = base64Data[dataIndex + 3];
-            
+
             b1 = base64Alphabet[base64Data[dataIndex]];
             b2 = base64Alphabet[base64Data[dataIndex + 1]];
-            
+
             if (marker0 != PAD && marker1 != PAD) {
-                //No PAD e.g 3cQl
                 b3 = base64Alphabet[marker0];
                 b4 = base64Alphabet[marker1];
-                
-                decodedData[encodedIndex] = (byte) (b1 << 2 | b2 >> 4);
+                decodedData[encodedIndex]     = (byte) (b1 << 2 | b2 >> 4);
                 decodedData[encodedIndex + 1] =
-                    (byte) (((b2 & 0xf) << 4) | ((b3 >> 2) & 0xf));
+                        (byte) (((b2 & 0xf) << 4) | ((b3 >> 2) & 0xf));
                 decodedData[encodedIndex + 2] = (byte) (b3 << 6 | b4);
             } else if (marker0 == PAD) {
-                //Two PAD e.g. 3c[Pad][Pad]
                 decodedData[encodedIndex] = (byte) (b1 << 2 | b2 >> 4);
-            } else if (marker1 == PAD) {
-                //One PAD e.g. 3cQ[Pad]
+            } else {
                 b3 = base64Alphabet[marker0];
-                
-                decodedData[encodedIndex] = (byte) (b1 << 2 | b2 >> 4);
+                decodedData[encodedIndex]     = (byte) (b1 << 2 | b2 >> 4);
                 decodedData[encodedIndex + 1] =
-                    (byte) (((b2 & 0xf) << 4) | ((b3 >> 2) & 0xf));
+                        (byte) (((b2 & 0xf) << 4) | ((b3 >> 2) & 0xf));
             }
             encodedIndex += 3;
         }
         return decodedData;
     }
-    
+
     /**
      * Discards any whitespace from a base-64 encoded block.
      *
-     * @param data The base-64 encoded data to discard the whitespace
-     * from.
+     * @param data The base-64 encoded data to discard the whitespace from.
      * @return The data, less whitespace (see RFC 2045).
      */
     static byte[] discardWhitespace(byte[] data) {
-        byte groomedData[] = new byte[data.length];
+        byte[] groomedData = new byte[data.length];
         int bytesCopied = 0;
-        
-        for (int i = 0; i < data.length; i++) {
-            switch (data[i]) {
-            case (byte) ' ' :
-            case (byte) '\n' :
-            case (byte) '\r' :
-            case (byte) '\t' :
+
+        for (byte datum : data) {
+            switch (datum) {
+                case (byte) ' ':
+                case (byte) '\n':
+                case (byte) '\r':
+                case (byte) '\t':
                     break;
-            default:
-                    groomedData[bytesCopied++] = data[i];
-            }
-        }
-
-        byte packedData[] = new byte[bytesCopied];
-
+                default:
+                    groomedData[bytesCopied++] = datum;
+            }
+        }
+
+        byte[] packedData = new byte[bytesCopied];
         System.arraycopy(groomedData, 0, packedData, 0, bytesCopied);
-
         return packedData;
     }
 
     /**
-     * Discards any characters outside of the base64 alphabet, per
-     * the requirements on page 25 of RFC 2045 - "Any characters
-     * outside of the base64 alphabet are to be ignored in base64
-     * encoded data."
+     * Discards any characters outside of the base64 alphabet, per the requirements
+     * on page 25 of RFC 2045 - "Any characters outside of the base64 alphabet are
+     * to be ignored in base64 encoded data."
      *
      * @param data The base-64 encoded data to groom
      * @return The data, less non-base64 characters (see RFC 2045).
      */
     static byte[] discardNonBase64(byte[] data) {
-        byte groomedData[] = new byte[data.length];
+        byte[] groomedData = new byte[data.length];
         int bytesCopied = 0;
 
-        for (int i = 0; i < data.length; i++) {
-            if (isBase64(data[i])) {
-                groomedData[bytesCopied++] = data[i];
-            }
-        }
-
-        byte packedData[] = new byte[bytesCopied];
-
+        for (byte datum : data) {
+            if (isBase64(datum)) {
+                groomedData[bytesCopied++] = datum;
+            }
+        }
+
+        byte[] packedData = new byte[bytesCopied];
         System.arraycopy(groomedData, 0, packedData, 0, bytesCopied);
-
         return packedData;
     }
 
-
-    // Implementation of the Encoder Interface
-
-    /**
-     * Encodes an Object using the base64 algorithm.  This method
-     * is provided in order to satisfy the requirements of the
-     * Encoder interface, and will throw an EncoderException if the
-     * supplied object is not of type byte[].
+    /**
+     * Encodes an Object using the base64 algorithm. This method is provided in order
+     * to satisfy the requirements of the Encoder interface, and will throw an
+     * EncoderException if the supplied object is not of type byte[].
      *
      * @param pObject Object to encode
-     * @return An object (of type byte[]) containing the 
-     *         base64 encoded data which corresponds to the byte[] supplied.
-     * @throws EncoderException if the parameter supplied is not
-     *                          of type byte[]
-     */
+     * @return An object (of type byte[]) containing the base64 encoded data which
+     *         corresponds to the byte[] supplied.
+     * @throws EncoderException if the parameter supplied is not of type byte[]
+     */
+    @Override
     public Object encode(Object pObject) throws EncoderException {
         if (!(pObject instanceof byte[])) {
             throw new EncoderException(
-                "Parameter supplied to Base64 encode is not a byte[]");
+                    "Parameter supplied to Base64 encode is not a byte[]");
         }
         return encode((byte[]) pObject);
     }
 
     /**
-     * Encodes a byte[] containing binary data, into a byte[] containing
-     * characters in the Base64 alphabet.
+     * Encodes a byte[] containing binary data, into a byte[] containing characters
+     * in the Base64 alphabet.
      *
      * @param pArray a byte array containing binary data
      * @return A byte array containing only Base64 character data
      */
+    @Override
     public byte[] encode(byte[] pArray) {
         return encodeBase64(pArray, false);
     }
-
 }

--- legacy/Base64.java
+++ bob/Base64.java
@@ -1,18 +1,18 @@
 /*
  * Copyright 2001-2004 The Apache Software Foundation.
- * 
+ *
  * 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.apache.commons.codec.binary;
 
@@ -23,153 +23,106 @@
 
 /**
  * Provides Base64 encoding and decoding as defined by RFC 2045.
- * 
- * <p>This class implements section <cite>6.8. Base64 Content-Transfer-Encoding</cite> 
- * from RFC 2045 <cite>Multipurpose Internet Mail Extensions (MIME) Part One: 
- * Format of Internet Message Bodies</cite> by Freed and Borenstein.</p> 
+ *
+ * <p>This class implements section <cite>6.8. Base64 Content-Transfer-Encoding</cite>
+ * from RFC 2045 <cite>Multipurpose Internet Mail Extensions (MIME) Part One:
+ * Format of Internet Message Bodies</cite> by Freed and Borenstein.</p>
+ *
+ * <p>Encoding and decoding are delegated to {@link java.util.Base64} (Java 8+).
+ * The hand-rolled alphabet tables and bit-shuffling from the 2004 original have
+ * been removed; this wrapper keeps the public API identical so existing callers
+ * require no changes.</p>
  *
  * @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045</a>
- * @author Apache Software Foundation
  * @since 1.0-dev
- * @version $Id: Base64.java,v 1.20 2004/05/24 00:21:24 ggregory Exp $
  */
 public class Base64 implements BinaryEncoder, BinaryDecoder {
 
     /**
      * Chunk size per RFC 2045 section 6.8.
-     * 
-     * <p>The {@value} character limit does not count the trailing CRLF, but counts 
+     *
+     * <p>The {@value} character limit does not count the trailing CRLF, but counts
      * all other characters, including any equal signs.</p>
-     * 
+     *
      * @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045 section 6.8</a>
      */
     static final int CHUNK_SIZE = 76;
 
     /**
      * Chunk separator per RFC 2045 section 2.1.
-     * 
+     *
      * @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045 section 2.1</a>
      */
     static final byte[] CHUNK_SEPARATOR = "\r\n".getBytes();
 
-    /**
-     * The base length.
-     */
-    static final int BASELENGTH = 255;
-
-    /**
-     * Lookup length.
-     */
-    static final int LOOKUPLENGTH = 64;
-
-    /**
-     * Used to calculate the number of bits in a byte.
-     */
-    static final int EIGHTBIT = 8;
-
-    /**
-     * Used when encoding something which has fewer than 24 bits.
-     */
-    static final int SIXTEENBIT = 16;
-
-    /**
-     * Used to determine how many bits data contains.
-     */
+    // Retained for binary compatibility with any code that reads these constants.
+    static final int BASELENGTH         = 255;
+    static final int LOOKUPLENGTH       = 64;
+    static final int EIGHTBIT           = 8;
+    static final int SIXTEENBIT         = 16;
     static final int TWENTYFOURBITGROUP = 24;
-
-    /**
-     * Used to get the number of Quadruples.
-     */
-    static final int FOURBYTE = 4;
-
-    /**
-     * Used to test the sign of a byte.
-     */
-    static final int SIGN = -128;
-    
-    /**
-     * Byte used to pad output.
-     */
-    static final byte PAD = (byte) '=';
-
-    // Create arrays to hold the base64 characters and a 
-    // lookup for base64 chars
-    private static byte[] base64Alphabet = new byte[BASELENGTH];
-    private static byte[] lookUpBase64Alphabet = new byte[LOOKUPLENGTH];
-
-    // Populating the lookup and character arrays
-    static {
-        for (int i = 0; i < BASELENGTH; i++) {
-            base64Alphabet[i] = (byte) -1;
-        }
-        for (int i = 'Z'; i >= 'A'; i--) {
-            base64Alphabet[i] = (byte) (i - 'A');
-        }
-        for (int i = 'z'; i >= 'a'; i--) {
-            base64Alphabet[i] = (byte) (i - 'a' + 26);
-        }
-        for (int i = '9'; i >= '0'; i--) {
-            base64Alphabet[i] = (byte) (i - '0' + 52);
-        }
-
-        base64Alphabet['+'] = 62;
-        base64Alphabet['/'] = 63;
-
-        for (int i = 0; i <= 25; i++) {
-            lookUpBase64Alphabet[i] = (byte) ('A' + i);
-        }
-
-        for (int i = 26, j = 0; i <= 51; i++, j++) {
-            lookUpBase64Alphabet[i] = (byte) ('a' + j);
-        }
-
-        for (int i = 52, j = 0; i <= 61; i++, j++) {
-            lookUpBase64Alphabet[i] = (byte) ('0' + j);
-        }
-
-        lookUpBase64Alphabet[62] = (byte) '+';
-        lookUpBase64Alphabet[63] = (byte) '/';
-    }
-
-    private static boolean isBase64(byte octect) {
-        if (octect == PAD) {
+    static final int FOURBYTE           = 4;
+    static final int SIGN               = -128;
+    static final byte PAD               = (byte) '=';
+
+    /** Encoder for plain (non-chunked) Base64 — RFC 4648 Table 1. */
+    private static final java.util.Base64.Encoder ENCODER =
+            java.util.Base64.getEncoder();
+
+    /** Encoder for MIME-chunked Base64 — 76-char lines, CRLF separator. */
+    private static final java.util.Base64.Encoder MIME_ENCODER =
+            java.util.Base64.getMimeEncoder(CHUNK_SIZE, CHUNK_SEPARATOR);
+
+    /**
+     * Decoder that is lenient about whitespace and non-alphabet characters,
+     * matching the RFC 2045 requirement to ignore anything outside the alphabet.
+     * {@link java.util.Base64#getMimeDecoder()} skips all non-alphabet bytes,
+     * which is exactly what the original {@code discardNonBase64} did.
+     */
+    private static final java.util.Base64.Decoder DECODER =
+            java.util.Base64.getMimeDecoder();
+
+    // -----------------------------------------------------------------------
+    // Validation helpers
+    // -----------------------------------------------------------------------
+
+    /** Returns {@code true} if {@code octet} is a valid Base64 character or pad. */
+    private static boolean isBase64(byte octet) {
+        return octet == PAD
+                || (octet >= 'A' && octet <= 'Z')
+                || (octet >= 'a' && octet <= 'z')
+                || (octet >= '0' && octet <= '9')
+                || octet == '+'
+                || octet == '/';
+    }
+
+    /**
+     * Tests a given byte array to see if it contains only valid characters
+     * within the Base64 alphabet.
+     *
+     * @param arrayOctect byte array to test
+     * @return {@code true} if all bytes are valid Base64 characters (or the
+     *         array is empty); {@code false} otherwise
+     */
+    public static boolean isArrayByteBase64(byte[] arrayOctect) {
+        arrayOctect = discardWhitespace(arrayOctect);
+        if (arrayOctect.length == 0) {
             return true;
-        } else if (base64Alphabet[octect] == -1) {
-            return false;
-        } else {
-            return true;
-        }
-    }
-
-    /**
-     * Tests a given byte array to see if it contains
-     * only valid characters within the Base64 alphabet.
-     *
-     * @param arrayOctect byte array to test
-     * @return true if all bytes are valid characters in the Base64
-     *         alphabet or if the byte array is empty; false, otherwise
-     */
-    public static boolean isArrayByteBase64(byte[] arrayOctect) {
-
-        arrayOctect = discardWhitespace(arrayOctect);
-
-        int length = arrayOctect.length;
-        if (length == 0) {
-            // shouldn't a 0 length array be valid base64 data?
-            // return false;
-            return true;
-        }
-        for (int i = 0; i < length; i++) {
-            if (!isBase64(arrayOctect[i])) {
+        }
+        for (byte b : arrayOctect) {
+            if (!isBase64(b)) {
                 return false;
             }
         }
         return true;
     }
 
-    /**
-     * Encodes binary data using the base64 algorithm but
-     * does not chunk the output.
+    // -----------------------------------------------------------------------
+    // Static encoding helpers
+    // -----------------------------------------------------------------------
+
+    /**
+     * Encodes binary data using the base64 algorithm but does not chunk the output.
      *
      * @param binaryData binary data to encode
      * @return Base64 characters
@@ -179,8 +132,8 @@
     }
 
     /**
-     * Encodes binary data using the base64 algorithm and chunks
-     * the encoded output into 76 character blocks
+     * Encodes binary data using the base64 algorithm and chunks the encoded output
+     * into 76 character blocks.
      *
      * @param binaryData binary data to encode
      * @return Base64 characters chunked in 76 character blocks
@@ -189,323 +142,91 @@
         return encodeBase64(binaryData, true);
     }
 
-
-    /**
-     * Decodes an Object using the base64 algorithm.  This method
-     * is provided in order to satisfy the requirements of the
-     * Decoder interface, and will throw a DecoderException if the
-     * supplied object is not of type byte[].
-     *
-     * @param pObject Object to decode
-     * @return An object (of type byte[]) containing the 
-     *         binary data which corresponds to the byte[] supplied.
-     * @throws DecoderException if the parameter supplied is not
-     *                          of type byte[]
-     */
+    /**
+     * Encodes binary data using the base64 algorithm, optionally chunking the
+     * output into 76 character blocks.
+     *
+     * @param binaryData Array containing binary data to encode.
+     * @param isChunked  if {@code true} the output is wrapped at 76 characters
+     *                   with CRLF line separators (RFC 2045 MIME encoding)
+     * @return Base64-encoded data.
+     */
+    public static byte[] encodeBase64(byte[] binaryData, boolean isChunked) {
+        if (binaryData == null || binaryData.length == 0) {
+            return binaryData;
+        }
+        return isChunked
+                ? MIME_ENCODER.encode(binaryData)
+                : ENCODER.encode(binaryData);
+    }
+
+    // -----------------------------------------------------------------------
+    // Static decoding helper
+    // -----------------------------------------------------------------------
+
+    /**
+     * Decodes Base64 data into octets.
+     *
+     * <p>Non-Base64 characters (including whitespace) are silently discarded in
+     * accordance with RFC 2045 page 25.</p>
+     *
+     * @param base64Data Byte array containing Base64 data
+     * @return Array containing decoded data.
+     */
+    public static byte[] decodeBase64(byte[] base64Data) {
+        if (base64Data == null || base64Data.length == 0) {
+            return base64Data;
+        }
+        return DECODER.decode(base64Data);
+    }
+
+    // -----------------------------------------------------------------------
+    // BinaryDecoder interface
+    // -----------------------------------------------------------------------
+
+    /**
+     * Decodes an Object using the base64 algorithm.
+     *
+     * @param pObject Object to decode; must be a {@code byte[]}
+     * @return decoded {@code byte[]}
+     * @throws DecoderException if {@code pObject} is not a {@code byte[]}
+     */
+    @Override
     public Object decode(Object pObject) throws DecoderException {
         if (!(pObject instanceof byte[])) {
-            throw new DecoderException("Parameter supplied to Base64 decode is not a byte[]");
+            throw new DecoderException(
+                    "Parameter supplied to Base64 decode is not a byte[]");
         }
         return decode((byte[]) pObject);
     }
 
     /**
-     * Decodes a byte[] containing containing
-     * characters in the Base64 alphabet.
+     * Decodes a byte[] containing characters in the Base64 alphabet.
      *
      * @param pArray A byte array containing Base64 character data
      * @return a byte array containing binary data
      */
+    @Override
     public byte[] decode(byte[] pArray) {
         return decodeBase64(pArray);
     }
 
-    /**
-     * Encodes binary data using the base64 algorithm, optionally
-     * chunking the output into 76 character blocks.
-     *
-     * @param binaryData Array containing binary data to encode.
-     * @param isChunked if isChunked is true this encoder will chunk
-     *                  the base64 output into 76 character blocks
-     * @return Base64-encoded data.
-     */
-    public static byte[] encodeBase64(byte[] binaryData, boolean isChunked) {
-        int lengthDataBits = binaryData.length * EIGHTBIT;
-        int fewerThan24bits = lengthDataBits % TWENTYFOURBITGROUP;
-        int numberTriplets = lengthDataBits / TWENTYFOURBITGROUP;
-        byte encodedData[] = null;
-        int encodedDataLength = 0;
-        int nbrChunks = 0;
-
-        if (fewerThan24bits != 0) {
-            //data not divisible by 24 bit
-            encodedDataLength = (numberTriplets + 1) * 4;
-        } else {
-            // 16 or 8 bit
-            encodedDataLength = numberTriplets * 4;
-        }
-
-        // If the output is to be "chunked" into 76 character sections, 
-        // for compliance with RFC 2045 MIME, then it is important to 
-        // allow for extra length to account for the separator(s)
-        if (isChunked) {
-
-            nbrChunks =
-                (CHUNK_SEPARATOR.length == 0 ? 0 : (int) Math.ceil((float) encodedDataLength / CHUNK_SIZE));
-            encodedDataLength += nbrChunks * CHUNK_SEPARATOR.length;
-        }
-
-        encodedData = new byte[encodedDataLength];
-
-        byte k = 0, l = 0, b1 = 0, b2 = 0, b3 = 0;
-
-        int encodedIndex = 0;
-        int dataIndex = 0;
-        int i = 0;
-        int nextSeparatorIndex = CHUNK_SIZE;
-        int chunksSoFar = 0;
-
-        //log.debug("number of triplets = " + numberTriplets);
-        for (i = 0; i < numberTriplets; i++) {
-            dataIndex = i * 3;
-            b1 = binaryData[dataIndex];
-            b2 = binaryData[dataIndex + 1];
-            b3 = binaryData[dataIndex + 2];
-
-            //log.debug("b1= " + b1 +", b2= " + b2 + ", b3= " + b3);
-
-            l = (byte) (b2 & 0x0f);
-            k = (byte) (b1 & 0x03);
-
-            byte val1 =
-                ((b1 & SIGN) == 0) ? (byte) (b1 >> 2) : (byte) ((b1) >> 2 ^ 0xc0);
-            byte val2 =
-                ((b2 & SIGN) == 0) ? (byte) (b2 >> 4) : (byte) ((b2) >> 4 ^ 0xf0);
-            byte val3 =
-                ((b3 & SIGN) == 0) ? (byte) (b3 >> 6) : (byte) ((b3) >> 6 ^ 0xfc);
-
-            encodedData[encodedIndex] = lookUpBase64Alphabet[val1];
-            //log.debug( "val2 = " + val2 );
-            //log.debug( "k4   = " + (k<<4) );
-            //log.debug(  "vak  = " + (val2 | (k<<4)) );
-            encodedData[encodedIndex + 1] =
-                lookUpBase64Alphabet[val2 | (k << 4)];
-            encodedData[encodedIndex + 2] =
-                lookUpBase64Alphabet[(l << 2) | val3];
-            encodedData[encodedIndex + 3] = lookUpBase64Alphabet[b3 & 0x3f];
-
-            encodedIndex += 4;
-
-            // If we are chunking, let's put a chunk separator down.
-            if (isChunked) {
-                // this assumes that CHUNK_SIZE % 4 == 0
-                if (encodedIndex == nextSeparatorIndex) {
-                    System.arraycopy(
-                        CHUNK_SEPARATOR,
-                        0,
-                        encodedData,
-                        encodedIndex,
-                        CHUNK_SEPARATOR.length);
-                    chunksSoFar++;
-                    nextSeparatorIndex =
-                        (CHUNK_SIZE * (chunksSoFar + 1)) + 
-                        (chunksSoFar * CHUNK_SEPARATOR.length);
-                    encodedIndex += CHUNK_SEPARATOR.length;
-                }
-            }
-        }
-
-        // form integral number of 6-bit groups
-        dataIndex = i * 3;
-
-        if (fewerThan24bits == EIGHTBIT) {
-            b1 = binaryData[dataIndex];
-            k = (byte) (b1 & 0x03);
-            //log.debug("b1=" + b1);
-            //log.debug("b1<<2 = " + (b1>>2) );
-            byte val1 =
-                ((b1 & SIGN) == 0) ? (byte) (b1 >> 2) : (byte) ((b1) >> 2 ^ 0xc0);
-            encodedData[encodedIndex] = lookUpBase64Alphabet[val1];
-            encodedData[encodedIndex + 1] = lookUpBase64Alphabet[k << 4];
-            encodedData[encodedIndex + 2] = PAD;
-            encodedData[encodedIndex + 3] = PAD;
-        } else if (fewerThan24bits == SIXTEENBIT) {
-
-            b1 = binaryData[dataIndex];
-            b2 = binaryData[dataIndex + 1];
-            l = (byte) (b2 & 0x0f);
-            k = (byte) (b1 & 0x03);
-
-            byte val1 =
-                ((b1 & SIGN) == 0) ? (byte) (b1 >> 2) : (byte) ((b1) >> 2 ^ 0xc0);
-            byte val2 =
-                ((b2 & SIGN) == 0) ? (byte) (b2 >> 4) : (byte) ((b2) >> 4 ^ 0xf0);
-
-            encodedData[encodedIndex] = lookUpBase64Alphabet[val1];
-            encodedData[encodedIndex + 1] =
-                lookUpBase64Alphabet[val2 | (k << 4)];
-            encodedData[encodedIndex + 2] = lookUpBase64Alphabet[l << 2];
-            encodedData[encodedIndex + 3] = PAD;
-        }
-
-        if (isChunked) {
-            // we also add a separator to the end of the final chunk.
-            if (chunksSoFar < nbrChunks) {
-                System.arraycopy(
-                    CHUNK_SEPARATOR,
-                    0,
-                    encodedData,
-                    encodedDataLength - CHUNK_SEPARATOR.length,
-                    CHUNK_SEPARATOR.length);
-            }
-        }
-
-        return encodedData;
-    }
-
-    /**
-     * Decodes Base64 data into octects
-     *
-     * @param base64Data Byte array containing Base64 data
-     * @return Array containing decoded data.
-     */
-    public static byte[] decodeBase64(byte[] base64Data) {
-        // RFC 2045 requires that we discard ALL non-Base64 characters
-        base64Data = discardNonBase64(base64Data);
-
-        // handle the edge case, so we don't have to worry about it later
-        if (base64Data.length == 0) {
-            return new byte[0];
-        }
-
-        int numberQuadruple = base64Data.length / FOURBYTE;
-        byte decodedData[] = null;
-        byte b1 = 0, b2 = 0, b3 = 0, b4 = 0, marker0 = 0, marker1 = 0;
-
-        // Throw away anything not in base64Data
-
-        int encodedIndex = 0;
-        int dataIndex = 0;
-        {
-            // this sizes the output array properly - rlw
-            int lastData = base64Data.length;
-            // ignore the '=' padding
-            while (base64Data[lastData - 1] == PAD) {
-                if (--lastData == 0) {
-                    return new byte[0];
-                }
-            }
-            decodedData = new byte[lastData - numberQuadruple];
-        }
-        
-        for (int i = 0; i < numberQuadruple; i++) {
-            dataIndex = i * 4;
-            marker0 = base64Data[dataIndex + 2];
-            marker1 = base64Data[dataIndex + 3];
-            
-            b1 = base64Alphabet[base64Data[dataIndex]];
-            b2 = base64Alphabet[base64Data[dataIndex + 1]];
-            
-            if (marker0 != PAD && marker1 != PAD) {
-                //No PAD e.g 3cQl
-                b3 = base64Alphabet[marker0];
-                b4 = base64Alphabet[marker1];
-                
-                decodedData[encodedIndex] = (byte) (b1 << 2 | b2 >> 4);
-                decodedData[encodedIndex + 1] =
-                    (byte) (((b2 & 0xf) << 4) | ((b3 >> 2) & 0xf));
-                decodedData[encodedIndex + 2] = (byte) (b3 << 6 | b4);
-            } else if (marker0 == PAD) {
-                //Two PAD e.g. 3c[Pad][Pad]
-                decodedData[encodedIndex] = (byte) (b1 << 2 | b2 >> 4);
-            } else if (marker1 == PAD) {
-                //One PAD e.g. 3cQ[Pad]
-                b3 = base64Alphabet[marker0];
-                
-                decodedData[encodedIndex] = (byte) (b1 << 2 | b2 >> 4);
-                decodedData[encodedIndex + 1] =
-                    (byte) (((b2 & 0xf) << 4) | ((b3 >> 2) & 0xf));
-            }
-            encodedIndex += 3;
-        }
-        return decodedData;
-    }
-    
-    /**
-     * Discards any whitespace from a base-64 encoded block.
-     *
-     * @param data The base-64 encoded data to discard the whitespace
-     * from.
-     * @return The data, less whitespace (see RFC 2045).
-     */
-    static byte[] discardWhitespace(byte[] data) {
-        byte groomedData[] = new byte[data.length];
-        int bytesCopied = 0;
-        
-        for (int i = 0; i < data.length; i++) {
-            switch (data[i]) {
-            case (byte) ' ' :
-            case (byte) '\n' :
-            case (byte) '\r' :
-            case (byte) '\t' :
-                    break;
-            default:
-                    groomedData[bytesCopied++] = data[i];
-            }
-        }
-
-        byte packedData[] = new byte[bytesCopied];
-
-        System.arraycopy(groomedData, 0, packedData, 0, bytesCopied);
-
-        return packedData;
-    }
-
-    /**
-     * Discards any characters outside of the base64 alphabet, per
-     * the requirements on page 25 of RFC 2045 - "Any characters
-     * outside of the base64 alphabet are to be ignored in base64
-     * encoded data."
-     *
-     * @param data The base-64 encoded data to groom
-     * @return The data, less non-base64 characters (see RFC 2045).
-     */
-    static byte[] discardNonBase64(byte[] data) {
-        byte groomedData[] = new byte[data.length];
-        int bytesCopied = 0;
-
-        for (int i = 0; i < data.length; i++) {
-            if (isBase64(data[i])) {
-                groomedData[bytesCopied++] = data[i];
-            }
-        }
-
-        byte packedData[] = new byte[bytesCopied];
-
-        System.arraycopy(groomedData, 0, packedData, 0, bytesCopied);
-
-        return packedData;
-    }
-
-
-    // Implementation of the Encoder Interface
-
-    /**
-     * Encodes an Object using the base64 algorithm.  This method
-     * is provided in order to satisfy the requirements of the
-     * Encoder interface, and will throw an EncoderException if the
-     * supplied object is not of type byte[].
-     *
-     * @param pObject Object to encode
-     * @return An object (of type byte[]) containing the 
-     *         base64 encoded data which corresponds to the byte[] supplied.
-     * @throws EncoderException if the parameter supplied is not
-     *                          of type byte[]
-     */
+    // -----------------------------------------------------------------------
+    // BinaryEncoder interface
+    // -----------------------------------------------------------------------
+
+    /**
+     * Encodes an Object using the base64 algorithm.
+     *
+     * @param pObject Object to encode; must be a {@code byte[]}
+     * @return encoded {@code byte[]}
+     * @throws EncoderException if {@code pObject} is not a {@code byte[]}
+     */
+    @Override
     public Object encode(Object pObject) throws EncoderException {
         if (!(pObject instanceof byte[])) {
             throw new EncoderException(
-                "Parameter supplied to Base64 encode is not a byte[]");
+                    "Parameter supplied to Base64 encode is not a byte[]");
         }
         return encode((byte[]) pObject);
     }
@@ -517,8 +238,47 @@
      * @param pArray a byte array containing binary data
      * @return A byte array containing only Base64 character data
      */
+    @Override
     public byte[] encode(byte[] pArray) {
         return encodeBase64(pArray, false);
     }
 
+    // -----------------------------------------------------------------------
+    // Package-private utilities (kept for subclass / test compatibility)
+    // -----------------------------------------------------------------------
+
+    /**
+     * Discards any whitespace from a base-64 encoded block.
+     *
+     * @param data The base-64 encoded data to discard the whitespace from.
+     * @return The data, less whitespace (see RFC 2045).
+     */
+    static byte[] discardWhitespace(byte[] data) {
+        byte[] buf = new byte[data.length];
+        int n = 0;
+        for (byte b : data) {
+            if (b != ' ' && b != '\n' && b != '\r' && b != '\t') {
+                buf[n++] = b;
+            }
+        }
+        return java.util.Arrays.copyOf(buf, n);
+    }
+
+    /**
+     * Discards any characters outside of the base64 alphabet, per the requirements
+     * on page 25 of RFC 2045.
+     *
+     * @param data The base-64 encoded data to groom
+     * @return The data, less non-base64 characters (see RFC 2045).
+     */
+    static byte[] discardNonBase64(byte[] data) {
+        byte[] buf = new byte[data.length];
+        int n = 0;
+        for (byte b : data) {
+            if (isBase64(b)) {
+                buf[n++] = b;
+            }
+        }
+        return java.util.Arrays.copyOf(buf, n);
+    }
 }

--- bob/blocked.java
+++ bob/repaired.java
@@ -28,11 +28,6 @@
  * from RFC 2045 <cite>Multipurpose Internet Mail Extensions (MIME) Part One:
  * Format of Internet Message Bodies</cite> by Freed and Borenstein.</p>
  *
- * <p>Encoding and decoding are delegated to {@link java.util.Base64} (Java 8+).
- * The hand-rolled alphabet tables and bit-shuffling from the 2004 original have
- * been removed; this wrapper keeps the public API identical so existing callers
- * require no changes.</p>
- *
  * @see <a href="http://www.ietf.org/rfc/rfc2045.txt">RFC 2045</a>
  * @since 1.0-dev
  */
@@ -55,45 +50,80 @@
      */
     static final byte[] CHUNK_SEPARATOR = "\r\n".getBytes();
 
-    // Retained for binary compatibility with any code that reads these constants.
-    static final int BASELENGTH         = 255;
-    static final int LOOKUPLENGTH       = 64;
-    static final int EIGHTBIT           = 8;
-    static final int SIXTEENBIT         = 16;
+    /** The base length. */
+    static final int BASELENGTH = 255;
+
+    /** Lookup length. */
+    static final int LOOKUPLENGTH = 64;
+
+    /** Used to calculate the number of bits in a byte. */
+    static final int EIGHTBIT = 8;
+
+    /** Used when encoding something which has fewer than 24 bits. */
+    static final int SIXTEENBIT = 16;
+
+    /** Used to determine how many bits data contains. */
     static final int TWENTYFOURBITGROUP = 24;
-    static final int FOURBYTE           = 4;
-    static final int SIGN               = -128;
-    static final byte PAD               = (byte) '=';
-
-    /** Encoder for plain (non-chunked) Base64 — RFC 4648 Table 1. */
-    private static final java.util.Base64.Encoder ENCODER =
-            java.util.Base64.getEncoder();
-
-    /** Encoder for MIME-chunked Base64 — 76-char lines, CRLF separator. */
-    private static final java.util.Base64.Encoder MIME_ENCODER =
-            java.util.Base64.getMimeEncoder(CHUNK_SIZE, CHUNK_SEPARATOR);
-
-    /**
-     * Decoder that is lenient about whitespace and non-alphabet characters,
-     * matching the RFC 2045 requirement to ignore anything outside the alphabet.
-     * {@link java.util.Base64#getMimeDecoder()} skips all non-alphabet bytes,
-     * which is exactly what the original {@code discardNonBase64} did.
-     */
-    private static final java.util.Base64.Decoder DECODER =
-            java.util.Base64.getMimeDecoder();
-
-    // -----------------------------------------------------------------------
-    // Validation helpers
-    // -----------------------------------------------------------------------
-
-    /** Returns {@code true} if {@code octet} is a valid Base64 character or pad. */
+
+    /** Used to get the number of Quadruples. */
+    static final int FOURBYTE = 4;
+
+    /** Used to test the sign of a byte. */
+    static final int SIGN = -128;
+
+    /** Byte used to pad output. */
+    static final byte PAD = (byte) '=';
+
+    private static final byte[] BASE64_ALPHABET = new byte[BASELENGTH];
+    private static final byte[] LOOKUP_BASE64_ALPHABET = new byte[LOOKUPLENGTH];
+
+    static {
+        for (int i = 0; i < BASELENGTH; i++) {
+            BASE64_ALPHABET[i] = (byte) -1;
+        }
+        for (int i = 'Z'; i >= 'A'; i--) {
+            BASE64_ALPHABET[i] = (byte) (i - 'A');
+        }
+        for (int i = 'z'; i >= 'a'; i--) {
+            BASE64_ALPHABET[i] = (byte) (i - 'a' + 26);
+        }
+        for (int i = '9'; i >= '0'; i--) {
+            BASE64_ALPHABET[i] = (byte) (i - '0' + 52);
+        }
+        BASE64_ALPHABET['+'] = 62;
+        BASE64_ALPHABET['/'] = 63;
+
+        for (int i = 0; i <= 25; i++) {
+            LOOKUP_BASE64_ALPHABET[i] = (byte) ('A' + i);
+        }
+        for (int i = 26, j = 0; i <= 51; i++, j++) {
+            LOOKUP_BASE64_ALPHABET[i] = (byte) ('a' + j);
+        }
+        for (int i = 52, j = 0; i <= 61; i++, j++) {
+            LOOKUP_BASE64_ALPHABET[i] = (byte) ('0' + j);
+        }
+        LOOKUP_BASE64_ALPHABET[62] = (byte) '+';
+        LOOKUP_BASE64_ALPHABET[63] = (byte) '/';
+    }
+
+    /**
+     * Returns {@code true} if {@code octet} is a valid Base64 character or pad.
+     *
+     * <p><strong>Note:</strong> if {@code octet} is negative its value is used
+     * directly as an array index, which will throw
+     * {@link ArrayIndexOutOfBoundsException} for values below {@code -1}
+     * (e.g. {@code 0xFF} cast to {@code byte} = {@code -1} is the array size
+     * boundary; any value below that is out of bounds). This matches the
+     * behaviour of the original implementation.</p>
+     */
     private static boolean isBase64(byte octet) {
-        return octet == PAD
-                || (octet >= 'A' && octet <= 'Z')
-                || (octet >= 'a' && octet <= 'z')
-                || (octet >= '0' && octet <= '9')
-                || octet == '+'
-                || octet == '/';
+        if (octet == PAD) {
+            return true;
+        } else if (BASE64_ALPHABET[octet] == -1) {
+            return false;
+        } else {
+            return true;
+        }
     }
 
     /**
@@ -106,20 +136,17 @@
      */
     public static boolean isArrayByteBase64(byte[] arrayOctect) {
         arrayOctect = discardWhitespace(arrayOctect);
-        if (arrayOctect.length == 0) {
+        int length = arrayOctect.length;
+        if (length == 0) {
             return true;
         }
-        for (byte b : arrayOctect) {
-            if (!isBase64(b)) {
+        for (int i = 0; i < length; i++) {
+            if (!isBase64(arrayOctect[i])) {
                 return false;
             }
         }
         return true;
     }
-
-    // -----------------------------------------------------------------------
-    // Static encoding helpers
-    // -----------------------------------------------------------------------
 
     /**
      * Encodes binary data using the base64 algorithm but does not chunk the output.
@@ -148,21 +175,112 @@
      *
      * @param binaryData Array containing binary data to encode.
      * @param isChunked  if {@code true} the output is wrapped at 76 characters
-     *                   with CRLF line separators (RFC 2045 MIME encoding)
+     *                   with CRLF line separators (RFC 2045 MIME encoding);
+     *                   a trailing CRLF is always appended after the last chunk
      * @return Base64-encoded data.
      */
     public static byte[] encodeBase64(byte[] binaryData, boolean isChunked) {
-        if (binaryData == null || binaryData.length == 0) {
-            return binaryData;
-        }
-        return isChunked
-                ? MIME_ENCODER.encode(binaryData)
-                : ENCODER.encode(binaryData);
-    }
-
-    // -----------------------------------------------------------------------
-    // Static decoding helper
-    // -----------------------------------------------------------------------
+        int lengthDataBits = binaryData.length * EIGHTBIT;
+        int fewerThan24bits = lengthDataBits % TWENTYFOURBITGROUP;
+        int numberTriplets = lengthDataBits / TWENTYFOURBITGROUP;
+        int encodedDataLength;
+        int nbrChunks = 0;
+
+        if (fewerThan24bits != 0) {
+            encodedDataLength = (numberTriplets + 1) * 4;
+        } else {
+            encodedDataLength = numberTriplets * 4;
+        }
+
+        if (isChunked) {
+            nbrChunks = CHUNK_SEPARATOR.length == 0
+                    ? 0
+                    : (int) Math.ceil((float) encodedDataLength / CHUNK_SIZE);
+            encodedDataLength += nbrChunks * CHUNK_SEPARATOR.length;
+        }
+
+        byte[] encodedData = new byte[encodedDataLength];
+
+        byte k, l, b1, b2, b3;
+        int encodedIndex = 0;
+        int dataIndex;
+        int i;
+        int nextSeparatorIndex = CHUNK_SIZE;
+        int chunksSoFar = 0;
+
+        for (i = 0; i < numberTriplets; i++) {
+            dataIndex = i * 3;
+            b1 = binaryData[dataIndex];
+            b2 = binaryData[dataIndex + 1];
+            b3 = binaryData[dataIndex + 2];
+
+            l = (byte) (b2 & 0x0f);
+            k = (byte) (b1 & 0x03);
+
+            byte val1 = ((b1 & SIGN) == 0)
+                    ? (byte) (b1 >> 2) : (byte) ((b1) >> 2 ^ 0xc0);
+            byte val2 = ((b2 & SIGN) == 0)
+                    ? (byte) (b2 >> 4) : (byte) ((b2) >> 4 ^ 0xf0);
+            byte val3 = ((b3 & SIGN) == 0)
+                    ? (byte) (b3 >> 6) : (byte) ((b3) >> 6 ^ 0xfc);
+
+            encodedData[encodedIndex]     = LOOKUP_BASE64_ALPHABET[val1];
+            encodedData[encodedIndex + 1] = LOOKUP_BASE64_ALPHABET[val2 | (k << 4)];
+            encodedData[encodedIndex + 2] = LOOKUP_BASE64_ALPHABET[(l << 2) | val3];
+            encodedData[encodedIndex + 3] = LOOKUP_BASE64_ALPHABET[b3 & 0x3f];
+            encodedIndex += 4;
+
+            if (isChunked) {
+                if (encodedIndex == nextSeparatorIndex) {
+                    System.arraycopy(
+                            CHUNK_SEPARATOR, 0,
+                            encodedData, encodedIndex,
+                            CHUNK_SEPARATOR.length);
+                    chunksSoFar++;
+                    nextSeparatorIndex = (CHUNK_SIZE * (chunksSoFar + 1))
+                            + (chunksSoFar * CHUNK_SEPARATOR.length);
+                    encodedIndex += CHUNK_SEPARATOR.length;
+                }
+            }
+        }
+
+        dataIndex = i * 3;
+
+        if (fewerThan24bits == EIGHTBIT) {
+            b1 = binaryData[dataIndex];
+            k = (byte) (b1 & 0x03);
+            byte val1 = ((b1 & SIGN) == 0)
+                    ? (byte) (b1 >> 2) : (byte) ((b1) >> 2 ^ 0xc0);
+            encodedData[encodedIndex]     = LOOKUP_BASE64_ALPHABET[val1];
+            encodedData[encodedIndex + 1] = LOOKUP_BASE64_ALPHABET[k << 4];
+            encodedData[encodedIndex + 2] = PAD;
+            encodedData[encodedIndex + 3] = PAD;
+        } else if (fewerThan24bits == SIXTEENBIT) {
+            b1 = binaryData[dataIndex];
+            b2 = binaryData[dataIndex + 1];
+            l = (byte) (b2 & 0x0f);
+            k = (byte) (b1 & 0x03);
+            byte val1 = ((b1 & SIGN) == 0)
+                    ? (byte) (b1 >> 2) : (byte) ((b1) >> 2 ^ 0xc0);
+            byte val2 = ((b2 & SIGN) == 0)
+                    ? (byte) (b2 >> 4) : (byte) ((b2) >> 4 ^ 0xf0);
+            encodedData[encodedIndex]     = LOOKUP_BASE64_ALPHABET[val1];
+            encodedData[encodedIndex + 1] = LOOKUP_BASE64_ALPHABET[val2 | (k << 4)];
+            encodedData[encodedIndex + 2] = LOOKUP_BASE64_ALPHABET[l << 2];
+            encodedData[encodedIndex + 3] = PAD;
+        }
+
+        if (isChunked) {
+            if (chunksSoFar < nbrChunks) {
+                System.arraycopy(
+                        CHUNK_SEPARATOR, 0,
+                        encodedData, encodedDataLength - CHUNK_SEPARATOR.length,
+                        CHUNK_SEPARATOR.length);
+            }
+        }
+
+        return encodedData;
+    }
 
     /**
      * Decodes Base64 data into octets.
@@ -174,10 +292,55 @@
      * @return Array containing decoded data.
      */
     public static byte[] decodeBase64(byte[] base64Data) {
-        if (base64Data == null || base64Data.length == 0) {
-            return base64Data;
-        }
-        return DECODER.decode(base64Data);
+        base64Data = discardNonBase64(base64Data);
+
+        if (base64Data.length == 0) {
+            return new byte[0];
+        }
+
+        int numberQuadruple = base64Data.length / FOURBYTE;
+        byte[] decodedData;
+        byte b1, b2, b3, b4, marker0, marker1;
+
+        int encodedIndex = 0;
+        int dataIndex;
+
+        {
+            int lastData = base64Data.length;
+            while (base64Data[lastData - 1] == PAD) {
+                if (--lastData == 0) {
+                    return new byte[0];
+                }
+            }
+            decodedData = new byte[lastData - numberQuadruple];
+        }
+
+        for (int i = 0; i < numberQuadruple; i++) {
+            dataIndex = i * 4;
+            marker0 = base64Data[dataIndex + 2];
+            marker1 = base64Data[dataIndex + 3];
+
+            b1 = BASE64_ALPHABET[base64Data[dataIndex]];
+            b2 = BASE64_ALPHABET[base64Data[dataIndex + 1]];
+
+            if (marker0 != PAD && marker1 != PAD) {
+                b3 = BASE64_ALPHABET[marker0];
+                b4 = BASE64_ALPHABET[marker1];
+                decodedData[encodedIndex]     = (byte) (b1 << 2 | b2 >> 4);
+                decodedData[encodedIndex + 1] =
+                        (byte) (((b2 & 0xf) << 4) | ((b3 >> 2) & 0xf));
+                decodedData[encodedIndex + 2] = (byte) (b3 << 6 | b4);
+            } else if (marker0 == PAD) {
+                decodedData[encodedIndex] = (byte) (b1 << 2 | b2 >> 4);
+            } else {
+                b3 = BASE64_ALPHABET[marker0];
+                decodedData[encodedIndex]     = (byte) (b1 << 2 | b2 >> 4);
+                decodedData[encodedIndex + 1] =
+                        (byte) (((b2 & 0xf) << 4) | ((b3 >> 2) & 0xf));
+            }
+            encodedIndex += 3;
+        }
+        return decodedData;
     }
 
     // -----------------------------------------------------------------------
@@ -244,7 +407,7 @@
     }
 
     // -----------------------------------------------------------------------
-    // Package-private utilities (kept for subclass / test compatibility)
+    // Package-private utilities
     // -----------------------------------------------------------------------
 
     /**
@@ -254,14 +417,22 @@
      * @return The data, less whitespace (see RFC 2045).
      */
     static byte[] discardWhitespace(byte[] data) {
-        byte[] buf = new byte[data.length];
-        int n = 0;
-        for (byte b : data) {
-            if (b != ' ' && b != '\n' && b != '\r' && b != '\t') {
-                buf[n++] = b;
-            }
-        }
-        return java.util.Arrays.copyOf(buf, n);
+        byte[] groomedData = new byte[data.length];
+        int bytesCopied = 0;
+        for (int i = 0; i < data.length; i++) {
+            switch (data[i]) {
+                case (byte) ' ':
+                case (byte) '\n':
+                case (byte) '\r':
+                case (byte) '\t':
+                    break;
+                default:
+                    groomedData[bytesCopied++] = data[i];
+            }
+        }
+        byte[] packedData = new byte[bytesCopied];
+        System.arraycopy(groomedData, 0, packedData, 0, bytesCopied);
+        return packedData;
     }
 
     /**
@@ -272,13 +443,15 @@
      * @return The data, less non-base64 characters (see RFC 2045).
      */
     static byte[] discardNonBase64(byte[] data) {
-        byte[] buf = new byte[data.length];
-        int n = 0;
-        for (byte b : data) {
-            if (isBase64(b)) {
-                buf[n++] = b;
-            }
-        }
-        return java.util.Arrays.copyOf(buf, n);
+        byte[] groomedData = new byte[data.length];
+        int bytesCopied = 0;
+        for (int i = 0; i < data.length; i++) {
+            if (isBase64(data[i])) {
+                groomedData[bytesCopied++] = data[i];
+            }
+        }
+        byte[] packedData = new byte[bytesCopied];
+        System.arraycopy(groomedData, 0, packedData, 0, bytesCopied);
+        return packedData;
     }
 }