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package com.sun.org.apache.xerces.internal.impl.dv.util;

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, Sandy Gao
@xerces.internal
@LastModified: Nov 2017
/** * 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. * * @xerces.internal * * @author Jeffrey Rodriguez * @author Sandy Gao * @LastModified: Nov 2017 */
public final class Base64 { static private final int BASELENGTH = 128; static private final int LOOKUPLENGTH = 64; static private final int TWENTYFOURBITGROUP = 24; static private final int EIGHTBIT = 8; static private final int SIXTEENBIT = 16; static private final int SIXBIT = 6; static private final int FOURBYTE = 4; static private final int SIGN = -128; static private final char PAD = '='; static private final boolean fDebug = false; static final private byte [] base64Alphabet = new byte[BASELENGTH]; static final private char [] lookUpBase64Alphabet = new char[LOOKUPLENGTH]; static { for (int i = 0; i < BASELENGTH; ++i) { base64Alphabet[i] = -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] = (char)('A'+i); for (int i = 26, j = 0; i<=51; i++, j++) lookUpBase64Alphabet[i] = (char)('a'+ j); for (int i = 52, j = 0; i<=61; i++, j++) lookUpBase64Alphabet[i] = (char)('0' + j); lookUpBase64Alphabet[62] = '+'; lookUpBase64Alphabet[63] = '/'; } 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 && base64Alphabet[octect] != -1); } protected static boolean isBase64(char octect) { return (isWhiteSpace(octect) || isPad(octect) || isData(octect)); }
Encodes hex octects into Base64
Params:
  • binaryData – Array containing binaryData
Returns:Encoded Base64 array
/** * 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; if (fDebug) { System.out.println("number of triplets = " + numberTriplets ); } for (int i=0; i<numberTriplets; i++) { b1 = binaryData[dataIndex++]; b2 = binaryData[dataIndex++]; b3 = binaryData[dataIndex++]; if (fDebug) { System.out.println( "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); if (fDebug) { System.out.println( "val2 = " + val2 ); System.out.println( "k4 = " + (k<<4)); System.out.println( "vak = " + (val2 | (k<<4))); } encodedData[encodedIndex++] = lookUpBase64Alphabet[ val1 ]; encodedData[encodedIndex++] = lookUpBase64Alphabet[ val2 | ( k<<4 )]; encodedData[encodedIndex++] = lookUpBase64Alphabet[ (l <<2 ) | val3 ]; encodedData[encodedIndex++] = lookUpBase64Alphabet[ b3 & 0x3f ]; } // form integral number of 6-bit groups if (fewerThan24bits == EIGHTBIT) { b1 = binaryData[dataIndex]; k = (byte) ( b1 &0x03 ); if (fDebug) { System.out.println("b1=" + b1); System.out.println("b1<<2 = " + (b1>>2) ); } byte val1 = ((b1 & SIGN)==0)?(byte)(b1>>2):(byte)((b1)>>2^0xc0); encodedData[encodedIndex++] = lookUpBase64Alphabet[ val1 ]; encodedData[encodedIndex++] = lookUpBase64Alphabet[ 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++] = lookUpBase64Alphabet[ val1 ]; encodedData[encodedIndex++] = lookUpBase64Alphabet[ val2 | ( k<<4 )]; encodedData[encodedIndex++] = lookUpBase64Alphabet[ l<<2 ]; encodedData[encodedIndex++] = PAD; } return new String(encodedData); }
Decodes Base64 data into octects
Params:
  • encoded – string containing Base64 data
Returns:Array containind decoded data.
/** * Decodes Base64 data into octects * * @param encoded string containing Base64 data * @return Array containind decoded data. */
public static byte[] decode(String encoded) { if (encoded == null) return null; char[] base64Data = encoded.toCharArray(); // remove white spaces int len = removeWhiteSpace(base64Data); if (len%FOURBYTE != 0) { return null;//should be divisible by 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++]) )) return null;//if found "no data" just return null b1 = base64Alphabet[d1]; b2 = base64Alphabet[d2]; b3 = base64Alphabet[d3]; b4 = base64Alphabet[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++]) )) { return null;//if found "no data" just return null } b1 = base64Alphabet[d1]; b2 = base64Alphabet[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 return null; 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 = base64Alphabet[ d3 ]; if ((b3 & 0x3 ) != 0)//last 2 bits should be zero return null; 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 { return null;//an error like "3c[Pad]r", "3cdX", "3cXd", "3cXX" where X is non data } } else { //No PAD e.g 3cQl b3 = base64Alphabet[ d3 ]; b4 = base64Alphabet[ 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.
Params:
  • data – the byte array of base64 data (with WS)
Returns: the new length
/** * 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; } }