org.apache.ws.security.util.Base64 Maven / Gradle / Ivy
/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.ws.security.util;
import org.apache.ws.security.WSSecurityException;
/**
* This class provides encode/decode for RFC 2045 Base64 as defined by RFC 2045,
* N. Freed and N. Borenstein. RFC 2045: Multipurpose Internet Mail Extensions
* (MIME) Part One: Format of Internet Message Bodies. Reference 1996 Available
* at: http://www.ietf.org/rfc/rfc2045.txt This class is used by XML Schema
* binary format validation
*
* This implementation does not encode/decode streaming data. You need the data
* that you will encode/decode already on a byte arrray.
*
* @author Jeffrey Rodriguez
* @author Sandy Gao
* @version $Id$
*/
public final class Base64 {
private static final int BASELENGTH = 128;
private static final int LOOKUPLENGTH = 64;
private static final int TWENTYFOURBITGROUP = 24;
private static final int EIGHTBIT = 8;
private static final int SIXTEENBIT = 16;
private static final int FOURBYTE = 4;
private static final int SIGN = -128;
private static final char PAD = '=';
private static final byte[] BASE_64_ALPHABET = new byte[BASELENGTH];
private static final char[] LOOKUP_BASE_64_ALPHABET = new char[LOOKUPLENGTH];
static {
for (int i = 0; i < BASELENGTH; ++i) {
BASE_64_ALPHABET[i] = -1;
}
for (int i = 'Z'; i >= 'A'; i--) {
BASE_64_ALPHABET[i] = (byte) (i - 'A');
}
for (int i = 'z'; i >= 'a'; i--) {
BASE_64_ALPHABET[i] = (byte) (i - 'a' + 26);
}
for (int i = '9'; i >= '0'; i--) {
BASE_64_ALPHABET[i] = (byte) (i - '0' + 52);
}
BASE_64_ALPHABET['+'] = 62;
BASE_64_ALPHABET['/'] = 63;
for (int i = 0; i <= 25; i++) {
LOOKUP_BASE_64_ALPHABET[i] = (char) ('A' + i);
}
for (int i = 26, j = 0; i <= 51; i++, j++) {
LOOKUP_BASE_64_ALPHABET[i] = (char) ('a' + j);
}
for (int i = 52, j = 0; i <= 61; i++, j++) {
LOOKUP_BASE_64_ALPHABET[i] = (char) ('0' + j);
}
LOOKUP_BASE_64_ALPHABET[62] = (char) '+';
LOOKUP_BASE_64_ALPHABET[63] = (char) '/';
}
protected static boolean isWhiteSpace(char octect) {
return (octect == 0x20 || octect == 0xd || octect == 0xa || octect == 0x9);
}
protected static boolean isPad(char octect) {
return (octect == PAD);
}
protected static boolean isData(char octect) {
return (octect < BASELENGTH && BASE_64_ALPHABET[octect] != -1);
}
protected static boolean isBase64(char octect) {
return (isWhiteSpace(octect) || isPad(octect) || isData(octect));
}
/**
* Encodes hex octects into Base64
*
* @param binaryData
* Array containing binaryData
* @return Encoded Base64 array
*/
public static String encode(byte[] binaryData) {
if (binaryData == null) {
return null;
}
int lengthDataBits = binaryData.length * EIGHTBIT;
if (lengthDataBits == 0) {
return "";
}
int fewerThan24bits = lengthDataBits % TWENTYFOURBITGROUP;
int numberTriplets = lengthDataBits / TWENTYFOURBITGROUP;
int numberQuartet = fewerThan24bits != 0 ? numberTriplets + 1
: numberTriplets;
char encodedData[] = null;
encodedData = new char[numberQuartet * 4];
byte k = 0, l = 0, b1 = 0, b2 = 0, b3 = 0;
int encodedIndex = 0;
int dataIndex = 0;
for (int i = 0; i < numberTriplets; i++) {
b1 = binaryData[dataIndex++];
b2 = binaryData[dataIndex++];
b3 = binaryData[dataIndex++];
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_BASE_64_ALPHABET[val1];
encodedData[encodedIndex++] = LOOKUP_BASE_64_ALPHABET[val2
| (k << 4)];
encodedData[encodedIndex++] = LOOKUP_BASE_64_ALPHABET[(l << 2)
| val3];
encodedData[encodedIndex++] = LOOKUP_BASE_64_ALPHABET[b3 & 0x3f];
}
// form integral number of 6-bit groups
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_BASE_64_ALPHABET[val1];
encodedData[encodedIndex++] = LOOKUP_BASE_64_ALPHABET[k << 4];
encodedData[encodedIndex++] = PAD;
encodedData[encodedIndex++] = 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_BASE_64_ALPHABET[val1];
encodedData[encodedIndex++] = LOOKUP_BASE_64_ALPHABET[val2
| (k << 4)];
encodedData[encodedIndex++] = LOOKUP_BASE_64_ALPHABET[l << 2];
encodedData[encodedIndex++] = PAD;
}
return new String(encodedData);
}
/**
* Decodes Base64 data into octets
*
* @param encoded
* string containing Base64 data
* @return Array containing decoded data.
*/
public static byte[] decode(String encoded) throws WSSecurityException {
if (encoded == null) {
return null;
}
char[] base64Data = encoded.toCharArray();
// remove white spaces
int len = removeWhiteSpace(base64Data);
if (len % FOURBYTE != 0) {
throw new WSSecurityException("decoding.divisible.four");
}
int numberQuadruple = (len / FOURBYTE);
if (numberQuadruple == 0) {
return new byte[0];
}
byte decodedData[] = null;
byte b1 = 0, b2 = 0, b3 = 0, b4 = 0;
char d1 = 0, d2 = 0, d3 = 0, d4 = 0;
int i = 0;
int encodedIndex = 0;
int dataIndex = 0;
decodedData = new byte[(numberQuadruple) * 3];
for (; i < numberQuadruple - 1; i++) {
if (!isData((d1 = base64Data[dataIndex++]))
|| !isData((d2 = base64Data[dataIndex++]))
|| !isData((d3 = base64Data[dataIndex++]))
|| !isData((d4 = base64Data[dataIndex++]))) {
throw new WSSecurityException("decoding.general");// if found
// "no data"
// just return
// null
}
b1 = BASE_64_ALPHABET[d1];
b2 = BASE_64_ALPHABET[d2];
b3 = BASE_64_ALPHABET[d3];
b4 = BASE_64_ALPHABET[d4];
decodedData[encodedIndex++] = (byte) (b1 << 2 | b2 >> 4);
decodedData[encodedIndex++] = (byte) (((b2 & 0xf) << 4) | ((b3 >> 2) & 0xf));
decodedData[encodedIndex++] = (byte) (b3 << 6 | b4);
}
if (!isData((d1 = base64Data[dataIndex++]))
|| !isData((d2 = base64Data[dataIndex++]))) {
throw new WSSecurityException("decoding.general");// if found
// "no data" just
// return null
}
b1 = BASE_64_ALPHABET[d1];
b2 = BASE_64_ALPHABET[d2];
d3 = base64Data[dataIndex++];
d4 = base64Data[dataIndex++];
if (!isData((d3)) || !isData((d4))) {// Check if they are PAD characters
if (isPad(d3) && isPad(d4)) { // Two PAD e.g. 3c[Pad][Pad]
if ((b2 & 0xf) != 0) {// last 4 bits should be zero
throw new WSSecurityException("decoding.general");
}
byte[] tmp = new byte[i * 3 + 1];
System.arraycopy(decodedData, 0, tmp, 0, i * 3);
tmp[encodedIndex] = (byte)(b1 << 2 | b2 >> 4);
return tmp;
} else if (!isPad(d3) && isPad(d4)) { // One PAD e.g. 3cQ[Pad]
b3 = BASE_64_ALPHABET[d3];
if ((b3 & 0x3) != 0) { // last 2 bits should be zero
throw new WSSecurityException("decoding.general");
}
byte[] tmp = new byte[i * 3 + 2];
System.arraycopy(decodedData, 0, tmp, 0, i * 3);
tmp[encodedIndex++] = (byte)(b1 << 2 | b2 >> 4);
tmp[encodedIndex] = (byte)(((b2 & 0xf) << 4) | ((b3 >> 2) & 0xf));
return tmp;
} else {
throw new WSSecurityException("decoding.general");// an error
// like
// "3c[Pad]r",
// "3cdX",
// "3cXd",
// "3cXX"
// where X is
// non data
}
} else { // No PAD e.g 3cQl
b3 = BASE_64_ALPHABET[d3];
b4 = BASE_64_ALPHABET[d4];
decodedData[encodedIndex++] = (byte)(b1 << 2 | b2 >> 4);
decodedData[encodedIndex++] = (byte)(((b2 & 0xf) << 4) | ((b3 >> 2) & 0xf));
decodedData[encodedIndex++] = (byte)(b3 << 6 | b4);
}
return decodedData;
}
/**
* remove WhiteSpace from MIME containing encoded Base64 data.
*
* @param data
* the byte array of base64 data (with WS)
* @return the new length
*/
protected static int removeWhiteSpace(char[] data) {
if (data == null) {
return 0;
}
// count characters that's not whitespace
int newSize = 0;
int len = data.length;
for (int i = 0; i < len; i++) {
if (!isWhiteSpace(data[i])) {
data[newSize++] = data[i];
}
}
return newSize;
}
}
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