//
-// System.Security.Cryptography.FromBase64Transform
+// System.Security.Cryptography.FromBase64Transform.cs
//
-// Author:
-// Sergey Chaban (serge@wildwestsoftware.com)
+// Authors:
+// Sergey Chaban (serge@wildwestsoftware.com)
+// Sebastien Pouliot <sebastien@ximian.com>
+//
+// Copyright (C) 2004-2005 Novell, Inc (http://www.novell.com)
+//
+// 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.
//
-using System;
+using System.Globalization;
+using System.Runtime.InteropServices;
namespace System.Security.Cryptography {
[Serializable]
+ [ComVisible (true)]
public enum FromBase64TransformMode : int {
IgnoreWhiteSpaces,
DoNotIgnoreWhiteSpaces
}
+ [ComVisible (true)]
public class FromBase64Transform : ICryptoTransform {
private FromBase64TransformMode mode;
- private byte [] accumulator;
- private byte [] filterBuffer;
+ private byte[] accumulator;
private int accPtr;
private bool m_disposed;
+ private const byte TerminatorByte = ((byte) '=');
- /// <summary>
- /// Creates a new instance of the decoder
- /// with the default transformation mode (IgnoreWhiteSpaces).
- /// </summary>
public FromBase64Transform ()
: this (FromBase64TransformMode.IgnoreWhiteSpaces)
{
}
-
- /// <summary>
- /// Creates a new instance of the decoder
- /// with the specified transformation mode.
- /// </summary>
- public FromBase64Transform (FromBase64TransformMode mode)
+ public FromBase64Transform (FromBase64TransformMode whitespaces)
{
- this.mode = mode;
+ this.mode = whitespaces;
accumulator = new byte [4];
- filterBuffer = new byte [4];
accPtr = 0;
m_disposed = false;
}
Dispose (false);
}
-
- /// <summary>
- /// </summary>
public bool CanTransformMultipleBlocks {
- get {
- return false;
- }
+ get { return false; }
}
public virtual bool CanReuseTransform {
- get { return false; }
+ get { return true; }
}
- /// <summary>
- /// Returns the input block size for the Base64 decoder.
- /// </summary>
- /// <remarks>
- /// The input block size for Base64 decoder is always 1 byte.
- /// </remarks>
public int InputBlockSize {
- get {
- return 1;
- }
+ get { return 1; }
}
-
- /// <summary>
- /// Returns the output block size for the Base64 decoder.
- /// </summary>
- /// <remarks>
- /// The value returned by this property is always 3.
- /// </remarks>
public int OutputBlockSize {
- get {
- return 3;
- }
+ get { return 3; }
}
public void Clear()
Dispose (true);
}
+#if NET_4_0
+ public void Dispose ()
+#else
void IDisposable.Dispose ()
+#endif
{
Dispose (true);
GC.SuppressFinalize (this); // Finalization is now unnecessary
protected virtual void Dispose (bool disposing)
{
if (!m_disposed) {
+ // zeroize data
+ if (accumulator != null)
+ Array.Clear (accumulator, 0, accumulator.Length);
+
// dispose unmanaged objects
if (disposing) {
// dispose managed objects
+ accumulator = null;
}
m_disposed = true;
}
}
- private int Filter (byte [] buffer, int offset, int count)
+ private byte[] lookupTable;
+
+ private byte lookup (byte input)
{
- int end = offset + count;
- int len = filterBuffer.Length;
- int ptr = 0;
- byte [] filter = this.filterBuffer;
-
- for (int i = offset; i < end; i++) {
- byte b = buffer [i];
- if (!Char.IsWhiteSpace ((char) b)) {
- if (ptr >= len) {
- len <<= 1;
- this.filterBuffer = new byte [len];
- Array.Copy(filter, 0, this.filterBuffer, 0, len >> 1);
- filter = this.filterBuffer;
- }
- filter [ptr++] = b;
- }
+ if (input >= lookupTable.Length) {
+ throw new FormatException (
+ Locale.GetText ("Invalid character in a Base-64 string."));
}
- return ptr;
- }
-
+ byte ret = lookupTable [input];
+ if (ret == Byte.MaxValue) {
+ throw new FormatException (
+ Locale.GetText ("Invalid character in a Base-64 string."));
+ }
- private byte [] lookupTable;
- private byte lookup(byte input) {
- byte ret;
- if ((input >= lookupTable.Length) || ((ret = lookupTable[input])==-1))
- throw new System.FormatException("Invalid character in a Base-64 string.");
- return ret;
+ return ret;
}
- private int DoTransform (byte [] inputBuffer,
- int inputOffset,
- int inputCount,
- byte [] outputBuffer,
- int outputOffset)
+ private int ProcessBlock (byte[] output, int offset)
{
- int full = inputCount >> 2;
- if (full == 0) return 0;
-
int rem = 0;
+ if (accumulator [3] == TerminatorByte)
+ rem++;
+ if (accumulator [2] == TerminatorByte)
+ rem++;
- if (inputBuffer[inputCount - 1] == (byte)'=') {
- ++rem;
- --full;
- }
-
- if (inputBuffer[inputCount - 2] == (byte)'=') ++rem;
-
- lookupTable = Base64Table.DecodeTable;
+ lookupTable = Base64Constants.DecodeTable;
int b0,b1,b2,b3;
- for (int i = 0; i < full; i++) {
- b0 = lookup (inputBuffer [inputOffset++]);
- b1 = lookup (inputBuffer [inputOffset++]);
- b2 = lookup (inputBuffer [inputOffset++]);
- b3 = lookup (inputBuffer [inputOffset++]);
-
- outputBuffer [outputOffset++] = (byte) ((b0 << 2) | (b1 >> 4));
- outputBuffer [outputOffset++] = (byte) ((b1 << 4) | (b2 >> 2));
- outputBuffer [outputOffset++] = (byte) ((b2 << 6) | b3);
- }
-
- int res = full * 3;
-
switch (rem) {
case 0:
+ b0 = lookup (accumulator [0]);
+ b1 = lookup (accumulator [1]);
+ b2 = lookup (accumulator [2]);
+ b3 = lookup (accumulator [3]);
+ output [offset++] = (byte) ((b0 << 2) | (b1 >> 4));
+ output [offset++] = (byte) ((b1 << 4) | (b2 >> 2));
+ output [offset] = (byte) ((b2 << 6) | b3);
break;
case 1:
- b0 = lookup (inputBuffer [inputOffset++]);
- b1 = lookup (inputBuffer [inputOffset++]);
- b2 = lookup (inputBuffer [inputOffset++]);
- outputBuffer [outputOffset++] = (byte) ((b0 << 2) | (b1 >> 4));
- outputBuffer [outputOffset++] = (byte) ((b1 << 4) | (b2 >> 2));
- res += 2;
+ b0 = lookup (accumulator [0]);
+ b1 = lookup (accumulator [1]);
+ b2 = lookup (accumulator [2]);
+ output [offset++] = (byte) ((b0 << 2) | (b1 >> 4));
+ output [offset] = (byte) ((b1 << 4) | (b2 >> 2));
break;
case 2:
- b0 = lookup (inputBuffer [inputOffset++]);
- b1 = lookup (inputBuffer [inputOffset++]);
- outputBuffer [outputOffset++] = (byte) ((b0 << 2) | (b1 >> 4));
- ++res;
- break;
- default:
+ b0 = lookup (accumulator [0]);
+ b1 = lookup (accumulator [1]);
+ output [offset] = (byte) ((b0 << 2) | (b1 >> 4));
break;
}
- return res;
+ return (3 - rem);
}
-
- /// <summary>
- /// </summary>
- public int TransformBlock (byte [] inputBuffer,
- int inputOffset,
- int inputCount,
- byte [] outputBuffer,
- int outputOffset)
+ private void CheckInputParameters (byte[] inputBuffer, int inputOffset, int inputCount)
{
- int n;
- byte [] src;
- int srcOff;
- int res = 0;
-
- if (mode == FromBase64TransformMode.IgnoreWhiteSpaces) {
- n = Filter (inputBuffer, inputOffset, inputCount);
- src = filterBuffer;
- srcOff = 0;
- } else {
- n = inputCount;
- src = inputBuffer;
- srcOff = inputOffset;
- }
+ if (inputBuffer == null)
+ throw new ArgumentNullException ("inputBuffer");
+ if (inputOffset < 0)
+ throw new ArgumentOutOfRangeException ("inputOffset", "< 0");
+ if (inputCount > inputBuffer.Length)
+ throw new OutOfMemoryException ("inputCount " + Locale.GetText ("Overflow"));
+ if (inputOffset > inputBuffer.Length - inputCount)
+ throw new ArgumentException ("inputOffset", Locale.GetText ("Overflow"));
+ if (inputCount < 0)
+ throw new OverflowException ("inputCount < 0");
+ }
+ public int TransformBlock (byte[] inputBuffer, int inputOffset, int inputCount, byte[] outputBuffer, int outputOffset)
+ {
+ if (m_disposed)
+ throw new ObjectDisposedException ("FromBase64Transform");
+ // LAMESPEC: undocumented exceptions
+ CheckInputParameters (inputBuffer, inputOffset, inputCount);
+ if ((outputBuffer == null) || (outputOffset < 0))
+ throw new FormatException ("outputBuffer");
- int count = accPtr + n;
+ int res = 0;
- if (count < 4) {
- Array.Copy (src, srcOff, accumulator, accPtr, n);
- accPtr = count;
- } else {
- byte [] tmpBuff = new byte [count];
- Array.Copy (accumulator, 0, tmpBuff, 0, accPtr);
- Array.Copy (src, srcOff, tmpBuff, accPtr, n);
- accPtr = count & 3;
- Array.Copy (src, srcOff + (n - accPtr), accumulator, 0, accPtr);
- try {
- res = DoTransform (tmpBuff, 0, count & (~3), outputBuffer, outputOffset) ;
+ while (inputCount > 0) {
+ if (accPtr < 4) {
+ byte b = inputBuffer [inputOffset++];
+ if (mode == FromBase64TransformMode.IgnoreWhiteSpaces) {
+ if (!Char.IsWhiteSpace ((char) b))
+ accumulator [accPtr++] = b;
+ } else {
+ // don't ignore, we'll fail if bad data is provided
+ accumulator [accPtr++] = b;
+ }
}
- catch (System.FormatException e) {
- throw e;
+ if (accPtr == 4) {
+ res += ProcessBlock (outputBuffer, outputOffset);
+ outputOffset += 3;
+ accPtr = 0;
}
+ inputCount--;
}
-
return res;
}
-
- /// <summary>
- /// </summary>
- public byte [] TransformFinalBlock (byte [] inputBuffer,
- int inputOffset,
- int inputCount)
+ public byte[] TransformFinalBlock (byte[] inputBuffer, int inputOffset, int inputCount)
{
- byte [] src;
- int srcOff;
- int n;
+ if (m_disposed)
+ throw new ObjectDisposedException ("FromBase64Transform");
+ // LAMESPEC: undocumented exceptions
+ CheckInputParameters (inputBuffer, inputOffset, inputCount);
+ int ws = 0;
+ int terminator = 0;
if (mode == FromBase64TransformMode.IgnoreWhiteSpaces) {
- n = Filter (inputBuffer, inputOffset, inputCount);
- src = filterBuffer;
- srcOff = 0;
+ // count whitespace inside string
+ for (int i=inputOffset, j=0; j < inputCount; i++, j++) {
+ if (Char.IsWhiteSpace ((char)inputBuffer [i]))
+ ws++;
+ }
+ // no more (useful) data
+ if (ws == inputCount)
+ return new byte [0];
+ // there may be whitespace after the terminator
+ int k = inputOffset + inputCount - 1;
+ int n = Math.Min (2, inputCount);
+ while (n > 0) {
+ char c = (char) inputBuffer [k--];
+ if (c == '=') {
+ terminator++;
+ n--;
+ } else if (Char.IsWhiteSpace (c)) {
+ continue;
+ } else {
+ break;
+ }
+ }
} else {
- n = inputCount;
- src = inputBuffer;
- srcOff = inputOffset;
- }
-
-
- int dataLen = accPtr + n;
- byte [] tmpBuf = new byte [dataLen];
-
- int resLen = ((dataLen) >> 2) * 3;
- byte [] res = new byte [resLen];
-
- Array.Copy (accumulator, 0, tmpBuf, 0, accPtr);
- Array.Copy (src, srcOff, tmpBuf, accPtr, n);
-
- int actLen;
- try {
- actLen = DoTransform (tmpBuf, 0, dataLen, res, 0);
+ if (inputBuffer [inputOffset + inputCount - 1] == TerminatorByte)
+ terminator++;
+ if (inputBuffer [inputOffset + inputCount - 2] == TerminatorByte)
+ terminator++;
}
- catch (System.FormatException e) {
- throw e;
+ // some terminators could already be in the accumulator
+ if ((inputCount < 4) && (terminator < 2)) {
+ if ((accPtr > 2) && (accumulator [3] == TerminatorByte))
+ terminator++;
+ if ((accPtr > 1) && (accumulator [2] == TerminatorByte))
+ terminator++;
}
- accPtr = 0;
-
- if (actLen < resLen) {
- byte [] newres = new byte [actLen];
+ int count = ((accPtr + inputCount - ws) >> 2) * 3 - terminator;
+ if (count <= 0)
+ return new byte [0];
- Array.Copy (res, newres, actLen);
- return newres;
- } else
- return res;
+ // allocate the "right" ammount (to avoid multiple allocation/copy)
+ byte[] result = new byte [count];
+ TransformBlock (inputBuffer, inputOffset, inputCount, result, 0);
+ return result;
}
-
- } // FromBase64Transform
-
-} // System.Security.Cryptography
+ }
+}
projects / mono.git / blobdiff