| /* |
| * 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; |
| |
| import org.apache.commons.codec.BinaryDecoder; |
| import org.apache.commons.codec.BinaryEncoder; |
| import org.apache.commons.codec.DecoderException; |
| import org.apache.commons.codec.EncoderException; |
| |
| /** |
| * 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> |
| * |
| * @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 |
| * 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. |
| */ |
| 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) { |
| 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])) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| /** |
| * Encodes binary data using the base64 algorithm but |
| * does not chunk the output. |
| * |
| * @param binaryData binary data to encode |
| * @return Base64 characters |
| */ |
| public static byte[] encodeBase64(byte[] binaryData) { |
| return encodeBase64(binaryData, false); |
| } |
| |
| /** |
| * 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 |
| */ |
| public static byte[] encodeBase64Chunked(byte[] binaryData) { |
| 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[] |
| */ |
| public Object decode(Object pObject) throws DecoderException { |
| if (!(pObject instanceof 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. |
| * |
| * @param pArray A byte array containing Base64 character data |
| * @return a byte array containing binary data |
| */ |
| 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[] |
| */ |
| public Object encode(Object pObject) throws EncoderException { |
| if (!(pObject instanceof byte[])) { |
| throw new EncoderException( |
| "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. |
| * |
| * @param pArray a byte array containing binary data |
| * @return A byte array containing only Base64 character data |
| */ |
| public byte[] encode(byte[] pArray) { |
| return encodeBase64(pArray, false); |
| } |
| |
| } |