/*
* UTF7Encoding.cs - Implementation of the
* "System.Text.UTF7Encoding" class.
*
* Copyright (c) 2002 Southern Storm Software, Pty Ltd
* Copyright (c) 2003, 2004, Novell, Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/
namespace System.Text{
using System;
using System.Runtime.InteropServices;
[Serializable]
[ComVisible (true)]
[MonoLimitation ("Serialization format not compatible with .NET")]
#if ECMA_COMPAT
internal
#else
public
#endif
class UTF7Encoding : Encoding
{
// Magic number used by Windows for UTF-7.
internal const int UTF7_CODE_PAGE = 65000;
// Internal state.
private bool allowOptionals;
// Encoding rule table for 0x00-0x7F.
// 0 - full encode, 1 - direct, 2 - optional, 3 - encode plus.
private static readonly byte[] encodingRules = {
0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 1, 0, 0, // 00
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 10
1, 2, 2, 2, 2, 2, 2, 1, 1, 1, 2, 3, 1, 1, 1, 1, // 20
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 1, // 30
2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, // 40
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 0, 2, 2, 2, // 50
2, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, // 60
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 0, 0, // 70
};
// Characters to use to encode 6-bit values in base64.
private const String base64Chars =
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
// Map bytes in base64 to 6-bit values.
private static readonly sbyte[] base64Values = {
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 00
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 10
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63, // 20
52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1, // 30
-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, // 40
15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1, // 50
-1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, // 60
41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1, // 70
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 80
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 90
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // A0
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // B0
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // C0
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // D0
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // E0
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // F0
};
// Constructors.
public UTF7Encoding ()
: this (false)
{
}
public UTF7Encoding (bool allowOptionals)
: base (UTF7_CODE_PAGE)
{
this.allowOptionals = allowOptionals;
body_name = "utf-7";
encoding_name = "Unicode (UTF-7)";
header_name = "utf-7";
is_mail_news_display = true;
is_mail_news_save = true;
web_name = "utf-7";
windows_code_page = UnicodeEncoding.UNICODE_CODE_PAGE;
}
[ComVisible (false)]
public override int GetHashCode ()
{
int basis = base.GetHashCode ();
return allowOptionals ? -basis : basis;
}
[ComVisible(false)]
public override bool Equals (object value)
{
UTF7Encoding e = value as UTF7Encoding;
if (e == null)
return false;
return allowOptionals == e.allowOptionals &&
EncoderFallback.Equals (e.EncoderFallback) &&
DecoderFallback.Equals (e.DecoderFallback);
}
// Internal version of "GetByteCount" that can handle
// a rolling state between calls.
private static int InternalGetByteCount
(char[] chars, int index, int count, bool flush,
int leftOver, bool isInShifted, bool allowOptionals)
{
// Validate the parameters.
if (chars == null) {
throw new ArgumentNullException ("chars");
}
if (index < 0 || index > chars.Length) {
throw new ArgumentOutOfRangeException ("index", _("ArgRange_Array"));
}
if (count < 0 || count > (chars.Length - index)) {
throw new ArgumentOutOfRangeException ("count", _("ArgRange_Array"));
}
// Determine the length of the output.
int length = 0;
int leftOverSize = (leftOver >> 8);
byte[] rules = encodingRules;
int ch, rule;
while (count > 0) {
ch = (int)(chars[index++]);
--count;
if (ch < 0x0080) {
rule = rules[ch];
} else {
rule = 0;
}
switch (rule) {
case 0:
// Handle characters that must be fully encoded.
if ( !isInShifted ) {
++length;
leftOverSize = 0;
isInShifted = true;
}
leftOverSize += 16;
while (leftOverSize >= 6) {
++length;
leftOverSize -= 6;
}
break;
case 1:
// The character is encoded as itself.
if (isInShifted) {
if (leftOverSize != 0) {
// Flush the previous encoded sequence.
++length;
leftOverSize = 0;
}
// Count the "-" (sequence terminator)
++length;
isInShifted = false;
}
++length;
break;
case 2:
// The character may need to be encoded.
if (allowOptionals) {
goto case 1;
} else {
goto case 0;
}
// Not reached.
case 3:
// Encode the plus sign as "+-".
if (isInShifted) {
if (leftOverSize != 0) {
// Flush the previous encoded sequence.
++length;
leftOverSize = 0;
}
// Count the "-" (sequence terminator)
++length;
isInShifted = false;
}
length += 2;
break;
}
}
if (isInShifted && flush) {
if (leftOverSize != 0)
{
// Flush the previous encoded sequence.
++length;
}
// Count the "-" (sequence terminator)
++length;
}
// Return the length to the caller.
return length;
}
// Get the number of bytes needed to encode a character buffer.
public override int GetByteCount (char[] chars, int index, int count)
{
return InternalGetByteCount (chars, index, count, true, 0, false, allowOptionals);
}
// Internal version of "GetBytes" that can handle a
// rolling state between calls.
private static int InternalGetBytes
(char[] chars, int charIndex, int charCount,
byte[] bytes, int byteIndex, bool flush,
ref int leftOver, ref bool isInShifted, bool allowOptionals)
{
// Validate the parameters.
if (chars == null) {
throw new ArgumentNullException ("chars");
}
if (bytes == null) {
throw new ArgumentNullException ("bytes");
}
if (charIndex < 0 || charIndex > chars.Length) {
throw new ArgumentOutOfRangeException ("charIndex", _("ArgRange_Array"));
}
if (charCount < 0 || charCount > (chars.Length - charIndex)) {
throw new ArgumentOutOfRangeException ("charCount", _("ArgRange_Array"));
}
if (byteIndex < 0 || byteIndex > bytes.Length) {
throw new ArgumentOutOfRangeException ("byteIndex", _("ArgRange_Array"));
}
// Convert the characters.
int posn = byteIndex;
int byteLength = bytes.Length;
int leftOverSize = (leftOver >> 8);
int leftOverBits = (leftOver & 0xFF);
byte[] rules = encodingRules;
String base64 = base64Chars;
int ch, rule;
while (charCount > 0) {
ch = (int)(chars[charIndex++]);
--charCount;
if (ch < 0x0080) {
rule = rules[ch];
} else {
rule = 0;
}
switch (rule) {
case 0:
// Handle characters that must be fully encoded.
if (!isInShifted) {
if (posn >= byteLength) {
throw new ArgumentException (_("Arg_InsufficientSpace"), "bytes");
}
// Start the sequence
bytes[posn++] = (byte)'+';
isInShifted = true;
leftOverSize = 0;
}
leftOverBits = ((leftOverBits << 16) | ch);
leftOverSize += 16;
while (leftOverSize >= 6) {
if (posn >= byteLength) {
throw new ArgumentException (_("Arg_InsufficientSpace"), "bytes");
}
leftOverSize -= 6;
bytes[posn++] = (byte)(base64 [leftOverBits >> leftOverSize]);
leftOverBits &= ((1 << leftOverSize) - 1);
}
break;
case 1:
// The character is encoded as itself.
if (isInShifted) {
if (leftOverSize != 0) {
// Flush the previous encoded sequence.
if ((posn + 1) > byteLength) {
throw new ArgumentException (_("Arg_InsufficientSpace"), "bytes");
}
bytes[posn++] = (byte)(base64 [leftOverBits << (6 - leftOverSize)]);
}
if ((posn + 1) > byteLength) {
throw new ArgumentException (_("Arg_InsufficientSpace"), "bytes");
}
// Terminate the sequence
bytes[posn++] = (byte)'-';
isInShifted = false;
leftOverSize = 0;
leftOverBits = 0;
}
if (posn >= byteLength) {
throw new ArgumentException (_("Arg_InsufficientSpace"), "bytes");
}
bytes[posn++] = (byte)ch;
break;
case 2:
// The character may need to be encoded.
if (allowOptionals) {
goto case 1;
} else {
goto case 0;
}
// Not reached.
case 3:
// Encode the plus sign as "+-".
if (isInShifted) {
if (leftOverSize != 0) {
// Flush the previous encoded sequence.
if ((posn + 1) > byteLength) {
throw new ArgumentException (_("Arg_InsufficientSpace"), "bytes");
}
bytes[posn++] = (byte)(base64 [leftOverBits << (6 - leftOverSize)]);
}
if ((posn + 1) > byteLength) {
throw new ArgumentException (_("Arg_InsufficientSpace"), "bytes");
}
// Terminate the sequence
bytes[posn++] = (byte)'-';
isInShifted = false;
leftOverSize = 0;
leftOverBits = 0;
}
if ((posn + 2) > byteLength) {
throw new ArgumentException (_("Arg_InsufficientSpace"), "bytes");
}
bytes[posn++] = (byte)'+';
bytes[posn++] = (byte)'-';
break;
}
}
if (isInShifted && flush) {
// Flush the previous encoded sequence.
if (leftOverSize != 0) {
if ((posn + 1) > byteLength) {
throw new ArgumentException (_("Arg_InsufficientSpace"), "bytes");
}
bytes[posn++] = (byte)(base64 [leftOverBits << (6 - leftOverSize)]);
}
// Terminate the sequence
bytes[posn++] = (byte)'-';
leftOverSize = 0;
leftOverBits = 0;
isInShifted = false;
}
leftOver = ((leftOverSize << 8) | leftOverBits);
// Return the length to the caller.
return posn - byteIndex;
}
// Get the bytes that result from encoding a character buffer.
public override int GetBytes (char[] chars, int charIndex, int charCount,
byte[] bytes, int byteIndex)
{
int leftOver = 0;
bool isInShifted = false;
return InternalGetBytes (chars, charIndex, charCount, bytes, byteIndex, true,
ref leftOver, ref isInShifted, allowOptionals);
}
// Internal version of "GetCharCount" that can handle
// a rolling state between call.s
private static int InternalGetCharCount
(byte[] bytes, int index, int count, int leftOver)
{
// Validate the parameters.
if (bytes == null) {
throw new ArgumentNullException ("bytes");
}
if (index < 0 || index > bytes.Length) {
throw new ArgumentOutOfRangeException ("index", _("ArgRange_Array"));
}
if (count < 0 || count > (bytes.Length - index)) {
throw new ArgumentOutOfRangeException ("count", _("ArgRange_Array"));
}
// Determine the length of the result.
int length = 0;
int byteval;
bool normal = ((leftOver & 0x01000000) == 0);
bool prevIsPlus = ((leftOver & 0x02000000) != 0);
int leftOverSize = ((leftOver >> 16) & 0xFF);
sbyte[] base64 = base64Values;
while (count > 0) {
byteval = (int)(bytes[index++]);
--count;
if (normal) {
if (byteval != '+') {
// Directly-encoded character.
++length;
} else {
// Start of a base64-encoded character.
normal = false;
prevIsPlus = true;
}
} else {
// Process the next byte in a base64 sequence.
if (byteval == (int)'-') {
// End of a base64 sequence.
if (prevIsPlus) {
++length;
}
leftOverSize = 0;
normal = true;
} else if (base64 [byteval] != -1) {
// Extra character in a base64 sequence.
leftOverSize += 6;
if (leftOverSize >= 16) {
++length;
leftOverSize -= 16;
}
} else {
++length;
normal = true;
leftOverSize = 0;
}
prevIsPlus = false;
}
}
// Return the final length to the caller.
return length;
}
// Get the number of characters needed to decode a byte buffer.
public override int GetCharCount (byte[] bytes, int index, int count)
{
return InternalGetCharCount (bytes, index, count, 0);
}
// Internal version of "GetChars" that can handle a
// rolling state between calls.
private static int InternalGetChars (byte[] bytes, int byteIndex, int byteCount,
char[] chars, int charIndex, ref int leftOver)
{
// Validate the parameters.
if (bytes == null) {
throw new ArgumentNullException ("bytes");
}
if (chars == null) {
throw new ArgumentNullException ("chars");
}
if (byteIndex < 0 || byteIndex > bytes.Length) {
throw new ArgumentOutOfRangeException ("byteIndex", _("ArgRange_Array"));
}
if (byteCount < 0 || byteCount > (bytes.Length - byteIndex)) {
throw new ArgumentOutOfRangeException ("byteCount", _("ArgRange_Array"));
}
if (charIndex < 0 || charIndex > chars.Length) {
throw new ArgumentOutOfRangeException ("charIndex", _("ArgRange_Array"));
}
// Convert the bytes into characters.
int posn = charIndex;
int charLength = chars.Length;
int byteval, b64value;
bool normal = ((leftOver & 0x01000000) == 0);
bool prevIsPlus = ((leftOver & 0x02000000) != 0);
bool afterHighSurrogate = ((leftOver & 0x04000000) != 0);
int leftOverSize = ((leftOver >> 16) & 0xFF);
int leftOverBits = (leftOver & 0xFFFF);
sbyte[] base64 = base64Values;
while (byteCount > 0) {
byteval = (int)(bytes[byteIndex++]);
--byteCount;
if (normal) {
if (byteval != '+') {
// Directly-encoded character.
if (posn >= charLength) {
throw new ArgumentException (_("Arg_InsufficientSpace"), "chars");
}
if (afterHighSurrogate) {
throw new ArgumentException (_("Arg_InvalidUTF7"), "chars");
}
chars[posn++] = (char)byteval;
} else {
// Start of a base64-encoded character.
normal = false;
prevIsPlus = true;
}
} else {
// Process the next byte in a base64 sequence.
if (byteval == (int)'-') {
// End of a base64 sequence.
if (prevIsPlus) {
if (posn >= charLength) {
throw new ArgumentException (_("Arg_InsufficientSpace"), "chars");
}
if (afterHighSurrogate) {
throw new ArgumentException (_("Arg_InvalidUTF7"), "chars");
}
chars[posn++] = '+';
}
// RFC1642 Rule #2
// When decoding, any bits at the end of the Modified Base64 sequence that
// do not constitute a complete 16-bit Unicode character are discarded.
// If such discarded bits are non-zero the sequence is ill-formed.
normal = true;
leftOverSize = 0;
leftOverBits = 0;
}
else if ((b64value = base64[byteval]) != -1)
{
// Extra character in a base64 sequence.
leftOverBits = (leftOverBits << 6) | b64value;
leftOverSize += 6;
if (leftOverSize >= 16) {
if (posn >= charLength) {
throw new ArgumentException (_("Arg_InsufficientSpace"), "chars");
}
leftOverSize -= 16;
char nextChar = (char)(leftOverBits >> leftOverSize);
if ((nextChar & 0xFC00) == 0xD800) {
afterHighSurrogate = true;
}
else if ((nextChar & 0xFC00) == 0xDC00) {
if (!afterHighSurrogate) {
throw new ArgumentException (_("Arg_InvalidUTF7"), "chars");
}
afterHighSurrogate = false;
}
chars[posn++] = nextChar;
leftOverBits &= ((1 << leftOverSize) - 1);
}
} else {
if (posn >= charLength) {
throw new ArgumentException (_("Arg_InsufficientSpace"), "chars");
}
if (afterHighSurrogate) {
throw new ArgumentException (_("Arg_InvalidUTF7"), "chars");
}
chars[posn++] = (char)byteval;
normal = true;
leftOverSize = 0;
leftOverBits = 0;
}
prevIsPlus = false;
}
}
leftOver = (leftOverBits | (leftOverSize << 16) |
(normal ? 0 : 0x01000000) |
(prevIsPlus ? 0x02000000 : 0) |
(afterHighSurrogate ? 0x04000000 : 0));
// Return the final length to the caller.
return posn - charIndex;
}
// Get the characters that result from decoding a byte buffer.
public override int GetChars (byte[] bytes, int byteIndex, int byteCount,
char[] chars, int charIndex)
{
int leftOver = 0;
int amount = InternalGetChars (bytes, byteIndex, byteCount, chars, charIndex, ref leftOver);
if ((leftOver & 0x04000000) != 0) {
throw new ArgumentException (_("Arg_InvalidUTF7"), "chars");
}
return amount;
}
// Get the maximum number of bytes needed to encode a
// specified number of characters.
public override int GetMaxByteCount (int charCount)
{
if (charCount < 0) {
throw new ArgumentOutOfRangeException ("charCount", _("ArgRange_NonNegative"));
}
if (charCount == 0)
return 0;
return 8 * (int) (charCount / 3) + (charCount % 3) * 3 + 2;
}
// Get the maximum number of characters needed to decode a
// specified number of bytes.
public override int GetMaxCharCount (int byteCount)
{
if (byteCount < 0) {
throw new ArgumentOutOfRangeException ("byteCount", _("ArgRange_NonNegative"));
}
return byteCount;
}
// Get a UTF7-specific decoder that is attached to this instance.
public override Decoder GetDecoder ()
{
return new UTF7Decoder ();
}
// Get a UTF7-specific encoder that is attached to this instance.
public override Encoder GetEncoder ()
{
return new UTF7Encoder (allowOptionals);
}
// UTF-7 decoder implementation.
private sealed class UTF7Decoder : Decoder
{
// Internal state.
private int leftOver;
// Constructor.
public UTF7Decoder ()
{
leftOver = 0;
}
// Override inherited methods.
public override int GetCharCount (byte[] bytes, int index, int count)
{
return InternalGetCharCount (bytes, index, count, leftOver);
}
public override int GetChars (byte[] bytes, int byteIndex,
int byteCount, char[] chars,
int charIndex)
{
return InternalGetChars (bytes, byteIndex, byteCount, chars, charIndex, ref leftOver);
}
} // class UTF7Decoder
// UTF-7 encoder implementation.
private sealed class UTF7Encoder : Encoder
{
private bool allowOptionals;
private int leftOver = 0;
private bool isInShifted = false;
// Constructor.
public UTF7Encoder (bool allowOptionals)
{
this.allowOptionals = allowOptionals;
}
// Override inherited methods.
public override int GetByteCount (char[] chars, int index,
int count, bool flush)
{
return InternalGetByteCount
(chars, index, count, flush, leftOver, isInShifted, allowOptionals);
}
public override int GetBytes (char[] chars, int charIndex,
int charCount, byte[] bytes,
int byteIndex, bool flush)
{
return InternalGetBytes (chars, charIndex, charCount,
bytes, byteIndex, flush,
ref leftOver, ref isInShifted, allowOptionals);
}
} // class UTF7Encoder
// a bunch of practically missing implementations (but should just work)
[CLSCompliantAttribute (false)]
[ComVisible(false)]
public override unsafe int GetByteCount (char *chars, int count)
{
return base.GetByteCount (chars, count);
}
[ComVisible(false)]
public override int GetByteCount (string s)
{
return base.GetByteCount (s);
}
[ComVisible(false)]
[CLSCompliantAttribute (false)]
public override unsafe int GetBytes (char *chars, int charCount, byte* bytes, int byteCount)
{
return base.GetBytes (chars, charCount, bytes, byteCount);
}
[ComVisible(false)]
public override int GetBytes (string s, int charIndex, int charCount, byte [] bytes, int byteIndex)
{
return base.GetBytes (s, charIndex, charCount, bytes, byteIndex);
}
[ComVisible(false)]
[CLSCompliantAttribute (false)]
public override unsafe int GetCharCount (byte *bytes, int count)
{
return base.GetCharCount (bytes, count);
}
[ComVisible(false)]
[CLSCompliantAttribute (false)]
public override unsafe int GetChars (byte* bytes, int byteCount, char* chars, int charCount)
{
return base.GetChars (bytes, byteCount, chars, charCount);
}
[ComVisible(false)]
public override string GetString (byte [] bytes, int index, int count)
{
return base.GetString (bytes, index, count);
}
}; // class UTF7Encoding
}; // namespace System.Text
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