{

static private final int BASELENGTH = 255;

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 byte PAD = (byte) '=';

static private byte [] base64Alphabet = new byte[BASELENGTH];

static private byte [] lookUpBase64Alphabet = new byte[LOOKUPLENGTH];

//static private final Log log = LogSource.getInstance("org.apache.commons.util.Base64");

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] = (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) '/';

}

public static boolean isBase64( String isValidString )

{

return isArrayByteBase64(isValidString.getBytes());

}

public static boolean isBase64( byte octect )

{

//shall we ignore white space? JEFF??

return (octect == PAD || base64Alphabet[octect] != -1);

}

public static boolean isArrayByteBase64( byte[] 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 ( !Base64.isBase64(arrayOctect[i]) )

return false;

}

return true;

}

/**

*/

public static byte[] encode( byte[] binaryData )

{

int lengthDataBits = binaryData.length*EIGHTBIT;

int fewerThan24bits = lengthDataBits%TWENTYFOURBITGROUP;

int numberTriplets = lengthDataBits/TWENTYFOURBITGROUP;

byte encodedData[] = null;

if (fewerThan24bits != 0)

{

//data not divisible by 24 bit

encodedData = new byte[ (numberTriplets + 1 ) * 4 ];

}

else

{

// 16 or 8 bit

encodedData = new byte[ numberTriplets * 4 ];

}

byte k = 0, l = 0, b1 = 0, b2 = 0, b3 = 0;

int encodedIndex = 0;

int dataIndex = 0;

int i = 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);

encodedIndex = i * 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);

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 ];

}

// form integral number of 6-bit groups

dataIndex = i*3;

encodedIndex = i*4;

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;

}

return encodedData;

}

/**

*/

public static byte[] decode( byte[] 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;

}