2010-04-07 Jb Evain <jbevain@novell.com>

[mcs.git] / class / corlib / System.Security.Cryptography / SHA1CryptoServiceProvider.cs

//
// System.Security.Cryptography.SHA1CryptoServiceProvider.cs
//
// Authors:
//      Matthew S. Ford (Matthew.S.Ford@Rose-Hulman.Edu)
//      Sebastien Pouliot (sebastien@ximian.com)
//
// Copyright 2001 by Matthew S. Ford.
// Copyright (C) 2004, 2005, 2008 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.
//

// Note:
// The MS Framework includes two (almost) identical class for SHA1.
//      SHA1Managed is a 100% managed implementation.
//      SHA1CryptoServiceProvider (this file) is a wrapper on CryptoAPI.
// Mono must provide those two class for binary compatibility.
// In our case both class are wrappers around a managed internal class SHA1Internal.

using System.Runtime.InteropServices;

namespace System.Security.Cryptography {

        internal class SHA1Internal {
        
                private const int BLOCK_SIZE_BYTES =  64;
                private uint[] _H;  // these are my chaining variables
                private ulong count;
                private byte[] _ProcessingBuffer;   // Used to start data when passed less than a block worth.
                private int _ProcessingBufferCount; // Counts how much data we have stored that still needs processed.
                private uint[] buff;

                public SHA1Internal () 
                {
                        _H = new uint[5];
                        _ProcessingBuffer = new byte[BLOCK_SIZE_BYTES];
                        buff = new uint[80];
                        
                        Initialize();
                }

                public void HashCore (byte[] rgb, int ibStart, int cbSize) 
                {
                        int i;

                        if (_ProcessingBufferCount != 0) {
                                if (cbSize < (BLOCK_SIZE_BYTES - _ProcessingBufferCount)) {
                                        System.Buffer.BlockCopy (rgb, ibStart, _ProcessingBuffer, _ProcessingBufferCount, cbSize);
                                        _ProcessingBufferCount += cbSize;
                                        return;
                                }
                                else {
                                        i = (BLOCK_SIZE_BYTES - _ProcessingBufferCount);
                                        System.Buffer.BlockCopy (rgb, ibStart, _ProcessingBuffer, _ProcessingBufferCount, i);
                                        ProcessBlock (_ProcessingBuffer, 0);
                                        _ProcessingBufferCount = 0;
                                        ibStart += i;
                                        cbSize -= i;
                                }
                        }

                        for (i = 0; i < cbSize - cbSize % BLOCK_SIZE_BYTES; i += BLOCK_SIZE_BYTES) {
                                ProcessBlock (rgb, (uint)(ibStart + i));
                        }

                        if (cbSize % BLOCK_SIZE_BYTES != 0) {
                                System.Buffer.BlockCopy (rgb, cbSize - cbSize % BLOCK_SIZE_BYTES + ibStart, _ProcessingBuffer, 0, cbSize % BLOCK_SIZE_BYTES);
                                _ProcessingBufferCount = cbSize % BLOCK_SIZE_BYTES;
                        }
                }
        
                public byte[] HashFinal () 
                {
                        byte[] hash = new byte[20];

                        ProcessFinalBlock (_ProcessingBuffer, 0, _ProcessingBufferCount);

                        for (int i=0; i<5; i++) {
                                for (int j=0; j<4; j++) {
                                        hash [i*4+j] = (byte)(_H[i] >> (8*(3-j)));
                                }
                        }

                        return hash;
                }

                public void Initialize () 
                {
                        count = 0;
                        _ProcessingBufferCount = 0;

                        _H[0] = 0x67452301;
                        _H[1] = 0xefcdab89;
                        _H[2] = 0x98badcfe;
                        _H[3] = 0x10325476;
                        _H[4] = 0xC3D2E1F0;
                }

                private void ProcessBlock(byte[] inputBuffer, uint inputOffset) 
                {
                        uint a, b, c, d, e;

                        count += BLOCK_SIZE_BYTES;

                        // abc removal would not work on the fields
                        uint[] _H = this._H;
                        uint[] buff = this.buff;
                        InitialiseBuff(buff, inputBuffer, inputOffset);
                        FillBuff(buff);

                        a = _H[0];
                        b = _H[1];
                        c = _H[2];
                        d = _H[3];
                        e = _H[4];

                        // This function was unrolled because it seems to be doubling our performance with current compiler/VM.
                        // Possibly roll up if this changes.

                        // ---- Round 1 --------
                        int i=0;
                        while (i < 20)
                        {
                                e += ((a << 5) | (a >> 27)) + (((c ^ d) & b) ^ d) + 0x5A827999 + buff[i];
                                b = (b << 30) | (b >> 2);

                                d += ((e << 5) | (e >> 27)) + (((b ^ c) & a) ^ c) + 0x5A827999 + buff[i+1];
                                a = (a << 30) | (a >> 2);

                                c += ((d << 5) | (d >> 27)) + (((a ^ b) & e) ^ b) + 0x5A827999 + buff[i+2];
                                e = (e << 30) | (e >> 2);

                                b += ((c << 5) | (c >> 27)) + (((e ^ a) & d) ^ a) + 0x5A827999 + buff[i+3];
                                d = (d << 30) | (d >> 2);

                                a += ((b << 5) | (b >> 27)) + (((d ^ e) & c) ^ e) + 0x5A827999 + buff[i+4];
                                c = (c << 30) | (c >> 2);
                                i += 5;
                        }

                        // ---- Round 2 --------
                        while (i < 40)
                        {
                                e += ((a << 5) | (a >> 27)) + (b ^ c ^ d) + 0x6ED9EBA1 + buff[i];
                                b = (b << 30) | (b >> 2);

                                d += ((e << 5) | (e >> 27)) + (a ^ b ^ c) + 0x6ED9EBA1 + buff[i + 1];
                                a = (a << 30) | (a >> 2);

                                c += ((d << 5) | (d >> 27)) + (e ^ a ^ b) + 0x6ED9EBA1 + buff[i + 2];
                                e = (e << 30) | (e >> 2);

                                b += ((c << 5) | (c >> 27)) + (d ^ e ^ a) + 0x6ED9EBA1 + buff[i + 3];
                                d = (d << 30) | (d >> 2);

                                a += ((b << 5) | (b >> 27)) + (c ^ d ^ e) + 0x6ED9EBA1 + buff[i + 4];
                                c = (c << 30) | (c >> 2);
                                i += 5;
                        }
                   
                        // ---- Round 3 --------
                        while (i < 60)
                        {
                                e += ((a << 5) | (a >> 27)) + ((b & c) | (b & d) | (c & d)) + 0x8F1BBCDC + buff[i];
                                b = (b << 30) | (b >> 2);

                                d += ((e << 5) | (e >> 27)) + ((a & b) | (a & c) | (b & c)) + 0x8F1BBCDC + buff[i + 1];
                                a = (a << 30) | (a >> 2);

                                c += ((d << 5) | (d >> 27)) + ((e & a) | (e & b) | (a & b)) + 0x8F1BBCDC + buff[i + 2];
                                e = (e << 30) | (e >> 2);

                                b += ((c << 5) | (c >> 27)) + ((d & e) | (d & a) | (e & a)) + 0x8F1BBCDC + buff[i + 3];
                                d = (d << 30) | (d >> 2);

                                a += ((b << 5) | (b >> 27)) + ((c & d) | (c & e) | (d & e)) + 0x8F1BBCDC + buff[i + 4];
                                c = (c << 30) | (c >> 2);
                                i += 5;
                        }

                        // ---- Round 4 --------
                        while (i < 80)
                        {
                                e += ((a << 5) | (a >> 27)) + (b ^ c ^ d) + 0xCA62C1D6 + buff[i];
                                b = (b << 30) | (b >> 2);

                                d += ((e << 5) | (e >> 27)) + (a ^ b ^ c) + 0xCA62C1D6 + buff[i + 1];
                                a = (a << 30) | (a >> 2);

                                c += ((d << 5) | (d >> 27)) + (e ^ a ^ b) + 0xCA62C1D6 + buff[i + 2];
                                e = (e << 30) | (e >> 2);

                                b += ((c << 5) | (c >> 27)) + (d ^ e ^ a) + 0xCA62C1D6 + buff[i + 3];
                                d = (d << 30) | (d >> 2);

                                a += ((b << 5) | (b >> 27)) + (c ^ d ^ e) + 0xCA62C1D6 + buff[i + 4];
                                c = (c << 30) | (c >> 2);
                                i += 5;
                        }

                        _H[0] += a;
                        _H[1] += b;
                        _H[2] += c;
                        _H[3] += d;
                        _H[4] += e;
                }

                private static void InitialiseBuff(uint[] buff, byte[] input, uint inputOffset)
                {
                        buff[0] = (uint)((input[inputOffset + 0] << 24) | (input[inputOffset + 1] << 16) | (input[inputOffset + 2] << 8) | (input[inputOffset + 3]));
                        buff[1] = (uint)((input[inputOffset + 4] << 24) | (input[inputOffset + 5] << 16) | (input[inputOffset + 6] << 8) | (input[inputOffset + 7]));
                        buff[2] = (uint)((input[inputOffset + 8] << 24) | (input[inputOffset + 9] << 16) | (input[inputOffset + 10] << 8) | (input[inputOffset + 11]));
                        buff[3] = (uint)((input[inputOffset + 12] << 24) | (input[inputOffset + 13] << 16) | (input[inputOffset + 14] << 8) | (input[inputOffset + 15]));
                        buff[4] = (uint)((input[inputOffset + 16] << 24) | (input[inputOffset + 17] << 16) | (input[inputOffset + 18] << 8) | (input[inputOffset + 19]));
                        buff[5] = (uint)((input[inputOffset + 20] << 24) | (input[inputOffset + 21] << 16) | (input[inputOffset + 22] << 8) | (input[inputOffset + 23]));
                        buff[6] = (uint)((input[inputOffset + 24] << 24) | (input[inputOffset + 25] << 16) | (input[inputOffset + 26] << 8) | (input[inputOffset + 27]));
                        buff[7] = (uint)((input[inputOffset + 28] << 24) | (input[inputOffset + 29] << 16) | (input[inputOffset + 30] << 8) | (input[inputOffset + 31]));
                        buff[8] = (uint)((input[inputOffset + 32] << 24) | (input[inputOffset + 33] << 16) | (input[inputOffset + 34] << 8) | (input[inputOffset + 35]));
                        buff[9] = (uint)((input[inputOffset + 36] << 24) | (input[inputOffset + 37] << 16) | (input[inputOffset + 38] << 8) | (input[inputOffset + 39]));
                        buff[10] = (uint)((input[inputOffset + 40] << 24) | (input[inputOffset + 41] << 16) | (input[inputOffset + 42] << 8) | (input[inputOffset + 43]));
                        buff[11] = (uint)((input[inputOffset + 44] << 24) | (input[inputOffset + 45] << 16) | (input[inputOffset + 46] << 8) | (input[inputOffset + 47]));
                        buff[12] = (uint)((input[inputOffset + 48] << 24) | (input[inputOffset + 49] << 16) | (input[inputOffset + 50] << 8) | (input[inputOffset + 51]));
                        buff[13] = (uint)((input[inputOffset + 52] << 24) | (input[inputOffset + 53] << 16) | (input[inputOffset + 54] << 8) | (input[inputOffset + 55]));
                        buff[14] = (uint)((input[inputOffset + 56] << 24) | (input[inputOffset + 57] << 16) | (input[inputOffset + 58] << 8) | (input[inputOffset + 59]));
                        buff[15] = (uint)((input[inputOffset + 60] << 24) | (input[inputOffset + 61] << 16) | (input[inputOffset + 62] << 8) | (input[inputOffset + 63]));
                }

                private static void FillBuff(uint[] buff)
                {
                        uint val;
                        for (int i = 16; i < 80; i += 8)
                        {
                                val = buff[i - 3] ^ buff[i - 8] ^ buff[i - 14] ^ buff[i - 16];
                                buff[i] = (val << 1) | (val >> 31);

                                val = buff[i - 2] ^ buff[i - 7] ^ buff[i - 13] ^ buff[i - 15];
                                buff[i + 1] = (val << 1) | (val >> 31);

                                val = buff[i - 1] ^ buff[i - 6] ^ buff[i - 12] ^ buff[i - 14];
                                buff[i + 2] = (val << 1) | (val >> 31);

                                val = buff[i + 0] ^ buff[i - 5] ^ buff[i - 11] ^ buff[i - 13];
                                buff[i + 3] = (val << 1) | (val >> 31);

                                val = buff[i + 1] ^ buff[i - 4] ^ buff[i - 10] ^ buff[i - 12];
                                buff[i + 4] = (val << 1) | (val >> 31);

                                val = buff[i + 2] ^ buff[i - 3] ^ buff[i - 9] ^ buff[i - 11];
                                buff[i + 5] = (val << 1) | (val >> 31);

                                val = buff[i + 3] ^ buff[i - 2] ^ buff[i - 8] ^ buff[i - 10];
                                buff[i + 6] = (val << 1) | (val >> 31);

                                val = buff[i + 4] ^ buff[i - 1] ^ buff[i - 7] ^ buff[i - 9];
                                buff[i + 7] = (val << 1) | (val >> 31);
                        }
                }
        
                private void ProcessFinalBlock (byte[] inputBuffer, int inputOffset, int inputCount) 
                {
                        ulong total = count + (ulong)inputCount;
                        int paddingSize = (56 - (int)(total % BLOCK_SIZE_BYTES));

                        if (paddingSize < 1)
                                paddingSize += BLOCK_SIZE_BYTES;

                        int length = inputCount+paddingSize+8;
                        byte[] fooBuffer = (length == 64) ? _ProcessingBuffer : new byte[length];

                        for (int i=0; i<inputCount; i++) {
                                fooBuffer[i] = inputBuffer[i+inputOffset];
                        }

                        fooBuffer[inputCount] = 0x80;
                        for (int i=inputCount+1; i<inputCount+paddingSize; i++) {
                                fooBuffer[i] = 0x00;
                        }

                        // I deal in bytes. The algorithm deals in bits.
                        ulong size = total << 3;
                        AddLength (size, fooBuffer, inputCount+paddingSize);
                        ProcessBlock (fooBuffer, 0);

                        if (length == 128)
                                ProcessBlock (fooBuffer, 64);
                }

                internal void AddLength (ulong length, byte[] buffer, int position)
                {
                        buffer [position++] = (byte)(length >> 56);
                        buffer [position++] = (byte)(length >> 48);
                        buffer [position++] = (byte)(length >> 40);
                        buffer [position++] = (byte)(length >> 32);
                        buffer [position++] = (byte)(length >> 24);
                        buffer [position++] = (byte)(length >> 16);
                        buffer [position++] = (byte)(length >>  8);
                        buffer [position]   = (byte)(length);
                }
        }

#if !MOONLIGHT

        [ComVisible (true)]
        public sealed class SHA1CryptoServiceProvider : SHA1 {

                private SHA1Internal sha;

                public SHA1CryptoServiceProvider () 
                {
                        sha = new SHA1Internal ();
                }

                ~SHA1CryptoServiceProvider () 
                {
                        Dispose (false);
                }

                protected override void Dispose (bool disposing) 
                {
                        // nothing new to do (managed implementation)
                        base.Dispose (disposing);
                }

                protected override void HashCore (byte[] rgb, int ibStart, int cbSize) 
                {
                        State = 1;
                        sha.HashCore (rgb, ibStart, cbSize);
                }

                protected override byte[] HashFinal () 
                {
                        State = 0;
                        return sha.HashFinal ();
                }

                public override void Initialize () 
                {
                        sha.Initialize ();
                }
        }
#endif // NET_2_1
}