org.frameworkset.coder.BASE64Decoder Maven / Gradle / Ivy
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package org.frameworkset.coder;
/**
* Copyright 2024 bboss
*
* 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.
*/
import java.io.IOException;
import java.io.OutputStream;
import java.io.PushbackInputStream;
public class BASE64Decoder extends CharacterDecoder {
private static final char[] pem_array = new char[]{'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/'};
private static final byte[] pem_convert_array = new byte[256];
byte[] decode_buffer = new byte[4];
public BASE64Decoder() {
}
protected int bytesPerAtom() {
return 4;
}
protected int bytesPerLine() {
return 72;
}
protected void decodeAtom(PushbackInputStream var1, OutputStream var2, int var3) throws IOException {
byte var5 = -1;
byte var6 = -1;
byte var7 = -1;
byte var8 = -1;
if (var3 < 2) {
throw new CEFormatException("BASE64Decoder: Not enough bytes for an atom.");
} else {
int var4;
do {
var4 = var1.read();
if (var4 == -1) {
throw new CEStreamExhausted();
}
} while(var4 == 10 || var4 == 13);
this.decode_buffer[0] = (byte)var4;
var4 = this.readFully(var1, this.decode_buffer, 1, var3 - 1);
if (var4 == -1) {
throw new CEStreamExhausted();
} else {
if (var3 > 3 && this.decode_buffer[3] == 61) {
var3 = 3;
}
if (var3 > 2 && this.decode_buffer[2] == 61) {
var3 = 2;
}
switch (var3) {
case 4:
var8 = pem_convert_array[this.decode_buffer[3] & 255];
case 3:
var7 = pem_convert_array[this.decode_buffer[2] & 255];
case 2:
var6 = pem_convert_array[this.decode_buffer[1] & 255];
var5 = pem_convert_array[this.decode_buffer[0] & 255];
default:
switch (var3) {
case 2:
var2.write((byte)(var5 << 2 & 252 | var6 >>> 4 & 3));
break;
case 3:
var2.write((byte)(var5 << 2 & 252 | var6 >>> 4 & 3));
var2.write((byte)(var6 << 4 & 240 | var7 >>> 2 & 15));
break;
case 4:
var2.write((byte)(var5 << 2 & 252 | var6 >>> 4 & 3));
var2.write((byte)(var6 << 4 & 240 | var7 >>> 2 & 15));
var2.write((byte)(var7 << 6 & 192 | var8 & 63));
}
}
}
}
}
static {
int var0;
for(var0 = 0; var0 < 255; ++var0) {
pem_convert_array[var0] = -1;
}
for(var0 = 0; var0 < pem_array.length; ++var0) {
pem_convert_array[pem_array[var0]] = (byte)var0;
}
}
}