package com.hwlcn.security.codec;
public class Base64 {
static final int CHUNK_SIZE = 76;
static final byte[] CHUNK_SEPARATOR = "\r\n".getBytes();
private static final int BASELENGTH = 255;
private static final int LOOKUPLENGTH = 64;
private static final int EIGHTBIT = 8;
private static final int SIXTEENBIT = 16;
private static final int TWENTYFOURBITGROUP = 24;
private static final int FOURBYTE = 4;
private static final int SIGN = -128;
private static final byte PAD = (byte) '=';
private static final byte[] base64Alphabet = new byte[BASELENGTH];
private static final byte[] lookUpBase64Alphabet = new byte[LOOKUPLENGTH];
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 (octect < 0 || base64Alphabet[octect] == -1) {
return false;
} else {
return true;
}
}
public static boolean isBase64(byte[] arrayOctect) {
arrayOctect = discardWhitespace(arrayOctect);
int length = arrayOctect.length;
if (length == 0) {
return true;
}
for (int i = 0; i < length; i++) {
if (!isBase64(arrayOctect[i])) {
return false;
}
}
return true;
}
static byte[] discardWhitespace(byte[] data) {
byte groomedData[] = new byte[data.length];
int bytesCopied = 0;
for (byte aByte : data) {
switch (aByte) {
case (byte) ' ':
case (byte) '\n':
case (byte) '\r':
case (byte) '\t':
break;
default:
groomedData[bytesCopied++] = aByte;
}
}
byte packedData[] = new byte[bytesCopied];
System.arraycopy(groomedData, 0, packedData, 0, bytesCopied);
return packedData;
}
public static String encodeToString(byte[] bytes) {
byte[] encoded = encode(bytes);
return CodecSupport.toString(encoded);
}
public static byte[] encodeChunked(byte[] binaryData) {
return encode(binaryData, true);
}
public static byte[] encode(byte[] pArray) {
return encode(pArray, false);
}
public static byte[] encode(byte[] binaryData, boolean isChunked) {
long binaryDataLength = binaryData.length;
long lengthDataBits = binaryDataLength * EIGHTBIT;
long fewerThan24bits = lengthDataBits % TWENTYFOURBITGROUP;
long tripletCount = lengthDataBits / TWENTYFOURBITGROUP;
long encodedDataLengthLong;
int chunckCount = 0;
if (fewerThan24bits != 0) {
encodedDataLengthLong = (tripletCount + 1) * 4;
} else {
encodedDataLengthLong = tripletCount * 4;
}
if (isChunked) {
chunckCount = (CHUNK_SEPARATOR.length == 0 ? 0 : (int) Math
.ceil((float) encodedDataLengthLong / CHUNK_SIZE));
encodedDataLengthLong += chunckCount * CHUNK_SEPARATOR.length;
}
if (encodedDataLengthLong > Integer.MAX_VALUE) {
throw new IllegalArgumentException(
"Input array too big, output array would be bigger than Integer.MAX_VALUE=" + Integer.MAX_VALUE);
}
int encodedDataLength = (int) encodedDataLengthLong;
byte encodedData[] = new byte[encodedDataLength];
byte k, l, b1, b2, b3;
int encodedIndex = 0;
int dataIndex;
int i;
int nextSeparatorIndex = CHUNK_SIZE;
int chunksSoFar = 0;
for (i = 0; i < tripletCount; i++) {
dataIndex = i * 3;
b1 = binaryData[dataIndex];
b2 = binaryData[dataIndex + 1];
b3 = binaryData[dataIndex + 2];
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];
encodedData[encodedIndex + 1] = lookUpBase64Alphabet[val2 | (k << 4)];
encodedData[encodedIndex + 2] = lookUpBase64Alphabet[(l << 2) | val3];
encodedData[encodedIndex + 3] = lookUpBase64Alphabet[b3 & 0x3f];
encodedIndex += 4;
if (isChunked) {
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;
}
}
}
dataIndex = i * 3;
if (fewerThan24bits == EIGHTBIT) {
b1 = binaryData[dataIndex];
k = (byte) (b1 & 0x03);
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 < chunckCount) {
System.arraycopy(CHUNK_SEPARATOR, 0, encodedData, encodedDataLength - CHUNK_SEPARATOR.length,
CHUNK_SEPARATOR.length);
}
}
return encodedData;
}
public static String decodeToString(String base64Encoded) {
byte[] encodedBytes = CodecSupport.toBytes(base64Encoded);
return decodeToString(encodedBytes);
}
public static String decodeToString(byte[] base64Encoded) {
byte[] decoded = decode(base64Encoded);
return CodecSupport.toString(decoded);
}
public static byte[] decode(String base64Encoded) {
byte[] bytes = CodecSupport.toBytes(base64Encoded);
return decode(bytes);
}
public static byte[] decode(byte[] base64Data) {
base64Data = discardNonBase64(base64Data);
if (base64Data.length == 0) {
return new byte[0];
}
int numberQuadruple = base64Data.length / FOURBYTE;
byte decodedData[];
byte b1, b2, b3, b4, marker0, marker1;
int encodedIndex = 0;
int dataIndex;
{
int lastData = base64Data.length;
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 {
// 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;
}
static byte[] discardNonBase64(byte[] data) {
byte groomedData[] = new byte[data.length];
int bytesCopied = 0;
for (byte aByte : data) {
if (isBase64(aByte)) {
groomedData[bytesCopied++] = aByte;
}
}
byte packedData[] = new byte[bytesCopied];
System.arraycopy(groomedData, 0, packedData, 0, bytesCopied);
return packedData;
}
}