com.upokecenter.mail.transforms.QuotedPrintableTransform Maven / Gradle / Ivy
package com.upokecenter.mail.transforms;
/*
Written by Peter O. in 2014.
Any copyright is dedicated to the Public Domain.
http://creativecommons.org/publicdomain/zero/1.0/
If you like this, you should donate to Peter O.
at: http://upokecenter.dreamhosters.com/articles/donate-now-2/
*/
import com.upokecenter.util.*;
import com.upokecenter.mail.*;
public final class QuotedPrintableTransform implements IByteReader {
private int lineCharCount;
private boolean lenientLineBreaks;
private byte[] buffer;
private int bufferIndex;
private int bufferCount;
private boolean checkStrictEncoding;
private int maxLineSize;
private int lastByte;
private boolean unget;
private IByteReader input;
public QuotedPrintableTransform (
IByteReader input,
boolean lenientLineBreaks,
int maxLineSize,
boolean checkStrictEncoding) {
this.maxLineSize = maxLineSize;
this.lenientLineBreaks = lenientLineBreaks;
this.checkStrictEncoding = checkStrictEncoding;
this.input = input;
this.lastByte = -1;
}
public QuotedPrintableTransform (
IByteReader input,
boolean lenientLineBreaks) {
this(input, lenientLineBreaks, 76, false);
}
public QuotedPrintableTransform (
IByteReader input,
boolean lenientLineBreaks,
int maxLineLength) {
this(
input, lenientLineBreaks, maxLineLength, false);
}
private void ResizeBuffer(int size) {
this.buffer = (this.buffer == null) ? ((new byte[size + 10])) : this.buffer;
if (size > this.buffer.length) {
byte[] newbuffer = new byte[size + 10];
System.arraycopy(this.buffer, 0, newbuffer, 0, this.buffer.length);
this.buffer = newbuffer;
}
this.bufferCount = size;
this.bufferIndex = 0;
}
private int ReadInputByte() {
if (this.unget) {
this.unget = false;
} else {
this.lastByte = this.input.read();
}
return this.lastByte;
}
private final int[] printable = new int[] { 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
public int read() {
if (this.bufferIndex < this.bufferCount) {
int ret = this.buffer[this.bufferIndex];
++this.bufferIndex;
if (this.bufferIndex == this.bufferCount) {
this.bufferCount = 0;
this.bufferIndex = 0;
}
ret &= 0xff;
return ret;
}
while (true) {
int c = this.ReadInputByte();
if (c < 0) {
// End of stream
return -1;
}
if (!this.checkStrictEncoding && printable[c]==1 && this.maxLineSize< 0) {
return c;
}
if (c == 0x0d) {
// CR
c = this.ReadInputByte();
if (c == 0x0a) {
// CRLF
this.ResizeBuffer(1);
this.buffer[0] = 0x0a;
this.lineCharCount = 0;
return 0x0d;
}
this.unget = true;
if (!this.lenientLineBreaks) {
throw new MessageDataException("Expected LF after CR");
}
// CR, so write CRLF
this.ResizeBuffer(1);
this.buffer[0] = 0x0a;
this.lineCharCount = 0;
return 0x0d;
}
if (c == 0x0a) { // LF
if (!this.lenientLineBreaks) {
throw new MessageDataException("Expected LF after CR");
}
// LF, so write CRLF
this.ResizeBuffer(1);
this.buffer[0] = 0x0a;
this.lineCharCount = 0;
return 0x0d;
}
if (c == '=') { // Equals
if (this.maxLineSize >= 0) {
++this.lineCharCount;
if (this.lineCharCount > this.maxLineSize) {
throw new
MessageDataException("Encoded quoted-printable line too long");
}
}
int b1 = this.ReadInputByte();
c = 0;
if (b1 >= '0' && b1 <= '9') {
c <<= 4;
c |= b1 - '0';
} else if (b1 >= 'A' && b1 <= 'F') {
c <<= 4;
c |= b1 + 10 - 'A';
} else if (b1 >= 'a' && b1 <= 'f') {
c <<= 4;
c |= b1 + 10 - 'a';
} else if (b1 == '\r') {
b1 = this.ReadInputByte();
if (b1 == '\n') {
// Soft line break
this.lineCharCount = 0;
continue;
}
if (this.lenientLineBreaks) {
this.lineCharCount = 0;
this.unget = true;
continue;
}
if (!this.checkStrictEncoding && (this.maxLineSize > 76 ||
this.maxLineSize < 0)) {
if (this.maxLineSize >= 0) {
++this.lineCharCount;
if (this.lineCharCount > this.maxLineSize) {
throw new
MessageDataException("Encoded quoted-printable line too long");
}
}
this.unget = true;
this.ResizeBuffer(1);
this.buffer[0] = (byte)'\r';
return '=';
}
throw new
MessageDataException("CR not followed by LF in quoted-printable");
} else if (b1 == -1) {
// Equals sign at end, ignore
return -1;
} else if (b1 == '\n' && this.lenientLineBreaks) {
// Soft line break
this.lineCharCount = 0;
continue;
} else {
if (!this.checkStrictEncoding && (this.maxLineSize > 76 ||
this.maxLineSize < 0)) {
// Unget the character, since it might
// start a valid hex encoding or need
// to be treated some other way
this.unget = true;
return '=';
}
throw new
MessageDataException("Invalid hex character in quoted-printable");
}
int b2 = this.ReadInputByte();
// At this point, only a hex character is expected
if (b2 >= '0' && b2 <= '9') {
c <<= 4;
c |= b2 - '0';
} else if (b2 >= 'A' && b2 <= 'F') {
c <<= 4;
c |= b2 + 10 - 'A';
} else if (b2 >= 'a' && b2 <= 'f') {
c <<= 4;
c |= b2 + 10 - 'a';
} else {
if (!this.checkStrictEncoding && (this.maxLineSize > 76 ||
this.maxLineSize < 0)) {
// Unget the character, since it might
// start a valid hex encoding or need
// to be treated some other way
this.unget = true;
if (this.maxLineSize >= 0) {
++this.lineCharCount;
if (this.lineCharCount > this.maxLineSize) {
throw new
MessageDataException("Encoded quoted-printable line too long");
}
}
this.ResizeBuffer(1);
this.buffer[0] = (byte)b1;
return '=';
}
throw new
MessageDataException("Invalid hex character in quoted-printable");
}
if (this.maxLineSize >= 0) {
this.lineCharCount += 2;
if (this.lineCharCount > this.maxLineSize) {
throw new
MessageDataException("Encoded quoted-printable line too long");
}
}
return c;
}
if (c == ' ' || c == '\t') {
// Space or tab. Since the quoted-printable spec
// requires decoders to delete spaces and tabs before
// CRLF, we need to create a lookahead buffer for
// tabs and spaces read to see if they precede CRLF.
int spaceCount = 1;
if (this.maxLineSize >= 0) {
++this.lineCharCount;
if (this.lineCharCount > this.maxLineSize) {
throw new
MessageDataException("Encoded quoted-printable line too long");
}
}
// In most cases, though, there will only be
// one space or tab
int c2 = this.ReadInputByte();
if (c2 != ' ' && c2 != '\t' && c2 != '\r' && c2 != '\n' && c2 >= 0) {
// Simple: Space before a character other than
// space, tab, CR, LF, or EOF
if (c2 != '=' && c2 > 0x20 && c2 < 0x7f) {
// Add the character to the buffer rather
// than ungetting, for printable ASCII except
// the Equals sign
this.ResizeBuffer(1);
this.buffer[0] = (byte)c2;
} else {
this.unget = true;
}
return c;
}
boolean endsWithLineBreak = false;
while (true) {
if ((c2 == '\n' && this.lenientLineBreaks) || c2 < 0) {
// EOF, or LF with lenient line breaks
this.unget = true;
endsWithLineBreak = true;
break;
}
if (c2 == '\r' && this.lenientLineBreaks) {
// CR with lenient line breaks
this.unget = true;
endsWithLineBreak = true;
break;
}
if (c2 == '\r') {
// CR, may or may not be a line break
c2 = this.ReadInputByte();
if (c2 == '\n') {
// LF, so it's a line break
this.lineCharCount = 0;
this.ResizeBuffer(1);
this.buffer[0] = (byte)'\n';
return 0x0d;
} else {
// Add the CR to the
// buffer, it won't be ignored
this.ResizeBuffer(spaceCount);
this.buffer[spaceCount - 1] = (byte)'\r';
}
if (!this.lenientLineBreaks) {
throw new MessageDataException("Expected LF after CR");
}
this.unget = true; // it's something else
++this.lineCharCount;
if (this.maxLineSize >= 0 && this.lineCharCount >
this.maxLineSize) {
throw new
MessageDataException("Encoded quoted-printable line too long");
}
break;
}
if (c2 != ' ' && c2 != '\t') {
// Not a space or tab
this.unget = true;
break;
}
// An additional space or tab
this.ResizeBuffer(spaceCount);
this.buffer[spaceCount - 1] = (byte)c2;
++spaceCount;
if (this.maxLineSize >= 0) {
++this.lineCharCount;
if (this.lineCharCount > this.maxLineSize) {
throw new
MessageDataException("Encoded quoted-printable line too long");
}
}
c2 = this.ReadInputByte();
}
// Ignore space/tab runs if the line ends in that run
if (!endsWithLineBreak) {
return c;
}
if (this.checkStrictEncoding) {
throw new MessageDataException("Space or tab at end of line");
}
this.bufferCount = 0;
continue;
}
if (c != '\t' && (c < 0x20 || c >= 0x7f)) {
// Invalid character
if (this.maxLineSize < 0) {
// Ignore the character
} else if (this.maxLineSize > 76) {
// Just increment the line count
++this.lineCharCount;
if (this.lineCharCount > this.maxLineSize) {
throw new
MessageDataException("Encoded quoted-printable line too long");
}
} else {
throw new MessageDataException("Invalid character in quoted-printable");
}
} else {
// Any other character
if (this.maxLineSize >= 0) {
++this.lineCharCount;
if (this.lineCharCount > this.maxLineSize) {
throw new
MessageDataException("Encoded quoted-printable line too long");
}
} else if (this.checkStrictEncoding && (c >= 0x7f || c < 0x20)) {
throw new MessageDataException("Invalid character");
}
return c;
}
}
}
}
© 2015 - 2025 Weber Informatics LLC | Privacy Policy