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Posted to dev@commons.apache.org by to...@apache.org on 2006/01/07 22:24:58 UTC
svn commit: r366921 -
/jakarta/commons/proper/codec/branches/2/src/java/org/apache/commons/codec/binary/base/Base64.java
Author: tobrien
Date: Sat Jan 7 13:24:54 2006
New Revision: 366921
URL: http://svn.apache.org/viewcvs?rev=366921&view=rev
Log:
Copying the Base64 class from codec.binary to the base subpackage
and making this class rely on instance variables. This is
the first step to creating a version of Base64 that supports
alternate lookup alphabets as well as the ability to
customize encoding behavior to comply with the numerous
definitions of Base64.
Added:
jakarta/commons/proper/codec/branches/2/src/java/org/apache/commons/codec/binary/base/Base64.java
Added: jakarta/commons/proper/codec/branches/2/src/java/org/apache/commons/codec/binary/base/Base64.java
URL: http://svn.apache.org/viewcvs/jakarta/commons/proper/codec/branches/2/src/java/org/apache/commons/codec/binary/base/Base64.java?rev=366921&view=auto
==============================================================================
--- jakarta/commons/proper/codec/branches/2/src/java/org/apache/commons/codec/binary/base/Base64.java (added)
+++ jakarta/commons/proper/codec/branches/2/src/java/org/apache/commons/codec/binary/base/Base64.java Sat Jan 7 13:24:54 2006
@@ -0,0 +1,554 @@
+/*
+ * Copyright 2001-2005 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.base;
+
+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 161350 2005-04-14 20:39:46Z ggregory $
+ */
+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>
+ */
+ 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>
+ */
+ final byte[] CHUNK_SEPARATOR = "\r\n".getBytes();
+
+ /**
+ * The base length.
+ */
+ final int BASELENGTH = 255;
+
+ /**
+ * Lookup length.
+ */
+ final int LOOKUPLENGTH = 64;
+
+ /**
+ * Used to calculate the number of bits in a byte.
+ */
+ final int EIGHTBIT = 8;
+
+ /**
+ * Used when encoding something which has fewer than 24 bits.
+ */
+ final int SIXTEENBIT = 16;
+
+ /**
+ * Used to determine how many bits data contains.
+ */
+ final int TWENTYFOURBITGROUP = 24;
+
+ /**
+ * Used to get the number of Quadruples.
+ */
+ final int FOURBYTE = 4;
+
+ /**
+ * Used to test the sign of a byte.
+ */
+ final int SIGN = -128;
+
+ /**
+ * Byte used to pad output.
+ */
+ final byte PAD = (byte) '=';
+
+ /**
+ * Contains the Base64 values <code>0</code> through <code>63</code> accessed by using character encodings as
+ * indices.
+ * <p>
+ * For example, <code>base64Alphabet['+']</code> returns <code>62</code>.
+ * </p>
+ * <p>
+ * The value of undefined encodings is <code>-1</code>.
+ * </p>
+ */
+ private byte[] base64Alphabet = new byte[BASELENGTH];
+
+ /**
+ * <p>
+ * Contains the Base64 encodings <code>A</code> through <code>Z</code>, followed by <code>a</code> through
+ * <code>z</code>, followed by <code>0</code> through <code>9</code>, followed by <code>+</code>, and
+ * <code>/</code>.
+ * </p>
+ * <p>
+ * This array is accessed by using character values as indices.
+ * </p>
+ * <p>
+ * For example, <code>lookUpBase64Alphabet[62] </code> returns <code>'+'</code>.
+ * </p>
+ */
+ private byte[] lookUpBase64Alphabet = new byte[LOOKUPLENGTH];
+
+ public static Base64 DEFAULT = new Base64();
+
+ public Base64() {
+ // Populating the lookup and character arrays
+ 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) '/';
+ }
+
+ /**
+ * Returns whether or not the <code>octect</code> is in the base 64 alphabet.
+ *
+ * @param octect The value to test
+ * @return <code>true</code> if the value is defined in the the base 64 alphabet, <code>false</code> otherwise.
+ */
+ private boolean isBase64(byte octect) {
+ if (octect == PAD) {
+ return true;
+ } else if (octect < 0 || 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 <code>true</code> if all bytes are valid characters in the Base64
+ * alphabet or if the byte array is empty; false, otherwise
+ */
+ public 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 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 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 <code>true</code> this encoder will chunk
+ * the base64 output into 76 character blocks
+ * @return Base64-encoded data.
+ */
+ public 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 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).
+ */
+ 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).
+ */
+ 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);
+ }
+
+}
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