2 // System.Security.Cryptography.HashAlgorithm.cs
5 // Matthew S. Ford (Matthew.S.Ford@Rose-Hulman.Edu)
6 // Sebastien Pouliot (sebastien@ximian.com)
8 // Copyright 2001 by Matthew S. Ford.
9 // Portions (C) 2002 Motus Technologies Inc. (http://www.motus.com)
10 // Copyright (C) 2004-2006 Novell, Inc (http://www.novell.com)
12 // Permission is hereby granted, free of charge, to any person obtaining
13 // a copy of this software and associated documentation files (the
14 // "Software"), to deal in the Software without restriction, including
15 // without limitation the rights to use, copy, modify, merge, publish,
16 // distribute, sublicense, and/or sell copies of the Software, and to
17 // permit persons to whom the Software is furnished to do so, subject to
18 // the following conditions:
20 // The above copyright notice and this permission notice shall be
21 // included in all copies or substantial portions of the Software.
23 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
27 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
28 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
29 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
32 using System.Globalization;
34 using System.Runtime.InteropServices;
36 namespace System.Security.Cryptography {
39 public abstract class HashAlgorithm : ICryptoTransform {
41 protected internal byte[] HashValue;
42 protected int HashSizeValue;
44 private bool disposed;
46 protected HashAlgorithm ()
51 public virtual bool CanTransformMultipleBlocks {
55 public virtual bool CanReuseTransform {
61 // same as System.IDisposable.Dispose() which is documented
65 public byte[] ComputeHash (byte[] buffer)
68 throw new ArgumentNullException ("buffer");
70 return ComputeHash (buffer, 0, buffer.Length);
73 public byte[] ComputeHash (byte[] buffer, int offset, int count)
76 throw new ObjectDisposedException ("HashAlgorithm");
78 throw new ArgumentNullException ("buffer");
80 throw new ArgumentOutOfRangeException ("offset", "< 0");
82 throw new ArgumentException ("count", "< 0");
83 // ordered to avoid possible integer overflow
84 if (offset > buffer.Length - count) {
85 throw new ArgumentException ("offset + count",
86 Locale.GetText ("Overflow"));
89 HashCore (buffer, offset, count);
90 HashValue = HashFinal ();
96 public byte[] ComputeHash (Stream inputStream)
98 // don't read stream unless object is ready to use
100 throw new ObjectDisposedException ("HashAlgorithm");
102 byte[] buffer = new byte [4096];
103 int len = inputStream.Read (buffer, 0, 4096);
105 HashCore (buffer, 0, len);
106 len = inputStream.Read (buffer, 0, 4096);
108 HashValue = HashFinal ();
113 public static HashAlgorithm Create ()
116 return new System.Security.Cryptography.SHA1CryptoServiceProvider ();
118 return Create ("System.Security.Cryptography.HashAlgorithm");
122 public static HashAlgorithm Create (string hashName)
124 return (HashAlgorithm) CryptoConfig.CreateFromName (hashName);
127 public virtual byte[] Hash {
129 if (HashValue == null) {
130 throw new CryptographicUnexpectedOperationException (
131 Locale.GetText ("No hash value computed."));
137 protected abstract void HashCore (byte[] array, int ibStart, int cbSize);
139 protected abstract byte[] HashFinal ();
141 public virtual int HashSize {
142 get { return HashSizeValue; }
145 public abstract void Initialize ();
147 protected virtual void Dispose (bool disposing)
152 public virtual int InputBlockSize {
156 public virtual int OutputBlockSize {
161 public void Dispose ()
163 void IDisposable.Dispose ()
167 GC.SuppressFinalize (this); // Finalization is now unnecessary
170 // LAMESPEC: outputBuffer is optional in 2.0 (i.e. can be null).
171 // However a null outputBuffer would throw a ExecutionEngineException under 1.x
172 public int TransformBlock (byte[] inputBuffer, int inputOffset, int inputCount, byte[] outputBuffer, int outputOffset)
174 if (inputBuffer == null)
175 throw new ArgumentNullException ("inputBuffer");
178 throw new ArgumentOutOfRangeException ("inputOffset", "< 0");
180 throw new ArgumentException ("inputCount");
182 // ordered to avoid possible integer overflow
183 if ((inputOffset < 0) || (inputOffset > inputBuffer.Length - inputCount))
184 throw new ArgumentException ("inputBuffer");
186 if (outputBuffer != null) {
187 if (outputOffset < 0) {
188 throw new ArgumentOutOfRangeException ("outputOffset", "< 0");
190 // ordered to avoid possible integer overflow
191 if (outputOffset > outputBuffer.Length - inputCount) {
192 throw new ArgumentException ("outputOffset + inputCount",
193 Locale.GetText ("Overflow"));
197 HashCore (inputBuffer, inputOffset, inputCount);
199 if (outputBuffer != null)
200 Buffer.BlockCopy (inputBuffer, inputOffset, outputBuffer, outputOffset, inputCount);
205 public byte[] TransformFinalBlock (byte[] inputBuffer, int inputOffset, int inputCount)
207 if (inputBuffer == null)
208 throw new ArgumentNullException ("inputBuffer");
210 throw new ArgumentException ("inputCount");
211 // ordered to avoid possible integer overflow
212 if (inputOffset > inputBuffer.Length - inputCount) {
213 throw new ArgumentException ("inputOffset + inputCount",
214 Locale.GetText ("Overflow"));
217 byte[] outputBuffer = new byte [inputCount];
219 // note: other exceptions are handled by Buffer.BlockCopy
220 Buffer.BlockCopy (inputBuffer, inputOffset, outputBuffer, 0, inputCount);
222 HashCore (inputBuffer, inputOffset, inputCount);
223 HashValue = HashFinal ();