SHA512Managed.cs source code in C# .NET

Source code for the .NET framework in C#

                        

Code:

/ Net / Net / 3.5.50727.3053 / DEVDIV / depot / DevDiv / releases / whidbey / netfxsp / ndp / clr / src / BCL / System / Security / Cryptography / SHA512Managed.cs / 1 / SHA512Managed.cs

                            // ==++== 
//
//   Copyright (c) Microsoft Corporation.  All rights reserved.
//
// ==--== 

// 
// SHA512Managed.cs 
//
// C# implementation of the proposed SHA-512 hash algorithm 
//

namespace System.Security.Cryptography {
    using System; 

    [System.Runtime.InteropServices.ComVisible(true)] 
    public class SHA512Managed : SHA512 
    {
        private byte[]   _buffer; 
        private ulong    _count; // Number of bytes in the hashed message
        private UInt64[] _stateSHA512;
        private UInt64[] _W;
 
        //
        // public constructors 
        // 

        public SHA512Managed() 
        {
            if (Utils.FipsAlgorithmPolicy == 1)
                throw new InvalidOperationException(Environment.GetResourceString("Cryptography_NonCompliantFIPSAlgorithm"));
 
            _stateSHA512 = new UInt64[8];
            _buffer = new byte[128]; 
            _W = new UInt64[80]; 

            InitializeState(); 
        }

        //
        // public methods 
        //
 
        public override void Initialize() { 
            InitializeState();
 
            // Zeroize potentially sensitive information.
            Array.Clear(_buffer, 0, _buffer.Length);
            Array.Clear(_W, 0, _W.Length);
        } 

        protected override void HashCore(byte[] rgb, int ibStart, int cbSize) { 
            _HashData(rgb, ibStart, cbSize); 
        }
 
        protected override byte[] HashFinal() {
            return _EndHash();
        }
 
        //
        // private methods 
        // 

        private void InitializeState() { 
            _count = 0;

            _stateSHA512[0] = 0x6a09e667f3bcc908;
            _stateSHA512[1] = 0xbb67ae8584caa73b; 
            _stateSHA512[2] = 0x3c6ef372fe94f82b;
            _stateSHA512[3] = 0xa54ff53a5f1d36f1; 
            _stateSHA512[4] = 0x510e527fade682d1; 
            _stateSHA512[5] = 0x9b05688c2b3e6c1f;
            _stateSHA512[6] = 0x1f83d9abfb41bd6b; 
            _stateSHA512[7] = 0x5be0cd19137e2179;
        }

        /* SHA512 block update operation. Continues an SHA message-digest 
           operation, processing another message block, and updating the
           context. 
           */ 

        private unsafe void _HashData(byte[] partIn, int ibStart, int cbSize) 
        {
            int bufferLen;
            int partInLen = cbSize;
            int partInBase = ibStart; 

            /* Compute length of buffer */ 
            bufferLen = (int) (_count & 0x7f); 

            /* Update number of bytes */ 
            _count += (ulong) partInLen;

            fixed (UInt64* stateSHA512 = _stateSHA512) {
                fixed (byte* buffer = _buffer) { 
                    fixed (UInt64* expandedBuffer = _W) {
                        if ((bufferLen > 0) && (bufferLen + partInLen >= 128)) { 
                            Buffer.InternalBlockCopy(partIn, partInBase, _buffer, bufferLen, 128 - bufferLen); 
                            partInBase += (128 - bufferLen);
                            partInLen -= (128 - bufferLen); 
                            SHATransform(expandedBuffer, stateSHA512, buffer);
                            bufferLen = 0;
                        }
 
                        /* Copy input to temporary buffer and hash */
                        while (partInLen >= 128) { 
                            Buffer.InternalBlockCopy(partIn, partInBase, _buffer, 0, 128); 
                            partInBase += 128;
                            partInLen -= 128; 
                            SHATransform(expandedBuffer, stateSHA512, buffer);
                        }

                        if (partInLen > 0) { 
                            Buffer.InternalBlockCopy(partIn, partInBase, _buffer, bufferLen, partInLen);
                        } 
                    } 
                }
            } 
        }

        /* SHA512 finalization. Ends an SHA512 message-digest operation, writing
           the message digest. 
           */
 
        private byte[] _EndHash() 
        {
            byte[]         pad; 
            int            padLen;
            ulong          bitCount;
            byte[]         hash = new byte[64]; // HashSizeValue = 512
 
            /* Compute padding: 80 00 00 ... 00 00 
             */ 
 
            padLen = 128 - (int)(_count & 0x7f);
            if (padLen <= 16) 
                padLen += 128;

            pad = new byte[padLen];
            pad[0] = 0x80; 

            //  Convert count to bit count 
            bitCount = _count * 8; 

            // If we ever have UInt128 for bitCount, then these need to be uncommented. 
            // Note that C# only looks at the low 6 bits of the shift value for ulongs,
            // so >>0 and >>64 are equal!

            //pad[padLen-16] = (byte) ((bitCount >> 120) & 0xff); 
            //pad[padLen-15] = (byte) ((bitCount >> 112) & 0xff);
            //pad[padLen-14] = (byte) ((bitCount >> 104) & 0xff); 
            //pad[padLen-13] = (byte) ((bitCount >> 96) & 0xff); 
            //pad[padLen-12] = (byte) ((bitCount >> 88) & 0xff);
            //pad[padLen-11] = (byte) ((bitCount >> 80) & 0xff); 
            //pad[padLen-10] = (byte) ((bitCount >> 72) & 0xff);
            //pad[padLen-9] = (byte) ((bitCount >> 64) & 0xff);
            pad[padLen-8] = (byte) ((bitCount >> 56) & 0xff);
            pad[padLen-7] = (byte) ((bitCount >> 48) & 0xff); 
            pad[padLen-6] = (byte) ((bitCount >> 40) & 0xff);
            pad[padLen-5] = (byte) ((bitCount >> 32) & 0xff); 
            pad[padLen-4] = (byte) ((bitCount >> 24) & 0xff); 
            pad[padLen-3] = (byte) ((bitCount >> 16) & 0xff);
            pad[padLen-2] = (byte) ((bitCount >> 8) & 0xff); 
            pad[padLen-1] = (byte) ((bitCount >> 0) & 0xff);

            /* Digest padding */
            _HashData(pad, 0, pad.Length); 

            /* Store digest */ 
            Utils.QuadWordToBigEndian (hash, _stateSHA512, 8); 

            HashValue = hash; 
            return hash;
        }

        private readonly static UInt64[] _K = { 
            0x428a2f98d728ae22, 0x7137449123ef65cd, 0xb5c0fbcfec4d3b2f, 0xe9b5dba58189dbbc,
            0x3956c25bf348b538, 0x59f111f1b605d019, 0x923f82a4af194f9b, 0xab1c5ed5da6d8118, 
            0xd807aa98a3030242, 0x12835b0145706fbe, 0x243185be4ee4b28c, 0x550c7dc3d5ffb4e2, 
            0x72be5d74f27b896f, 0x80deb1fe3b1696b1, 0x9bdc06a725c71235, 0xc19bf174cf692694,
            0xe49b69c19ef14ad2, 0xefbe4786384f25e3, 0x0fc19dc68b8cd5b5, 0x240ca1cc77ac9c65, 
            0x2de92c6f592b0275, 0x4a7484aa6ea6e483, 0x5cb0a9dcbd41fbd4, 0x76f988da831153b5,
            0x983e5152ee66dfab, 0xa831c66d2db43210, 0xb00327c898fb213f, 0xbf597fc7beef0ee4,
            0xc6e00bf33da88fc2, 0xd5a79147930aa725, 0x06ca6351e003826f, 0x142929670a0e6e70,
            0x27b70a8546d22ffc, 0x2e1b21385c26c926, 0x4d2c6dfc5ac42aed, 0x53380d139d95b3df, 
            0x650a73548baf63de, 0x766a0abb3c77b2a8, 0x81c2c92e47edaee6, 0x92722c851482353b,
            0xa2bfe8a14cf10364, 0xa81a664bbc423001, 0xc24b8b70d0f89791, 0xc76c51a30654be30, 
            0xd192e819d6ef5218, 0xd69906245565a910, 0xf40e35855771202a, 0x106aa07032bbd1b8, 
            0x19a4c116b8d2d0c8, 0x1e376c085141ab53, 0x2748774cdf8eeb99, 0x34b0bcb5e19b48a8,
            0x391c0cb3c5c95a63, 0x4ed8aa4ae3418acb, 0x5b9cca4f7763e373, 0x682e6ff3d6b2b8a3, 
            0x748f82ee5defb2fc, 0x78a5636f43172f60, 0x84c87814a1f0ab72, 0x8cc702081a6439ec,
            0x90befffa23631e28, 0xa4506cebde82bde9, 0xbef9a3f7b2c67915, 0xc67178f2e372532b,
            0xca273eceea26619c, 0xd186b8c721c0c207, 0xeada7dd6cde0eb1e, 0xf57d4f7fee6ed178,
            0x06f067aa72176fba, 0x0a637dc5a2c898a6, 0x113f9804bef90dae, 0x1b710b35131c471b, 
            0x28db77f523047d84, 0x32caab7b40c72493, 0x3c9ebe0a15c9bebc, 0x431d67c49c100d4c,
            0x4cc5d4becb3e42b6, 0x597f299cfc657e2a, 0x5fcb6fab3ad6faec, 0x6c44198c4a475817, 
        }; 

        private static unsafe void SHATransform (UInt64* expandedBuffer, UInt64* state, byte* block) 
        {
            UInt64 a, b, c, d, e, f, g, h;
            UInt64 aa, bb, cc, dd, ee, ff, hh, gg;
            UInt64 T1; 

            a = state[0]; 
            b = state[1]; 
            c = state[2];
            d = state[3]; 
            e = state[4];
            f = state[5];
            g = state[6];
            h = state[7]; 

            // fill in the first 16 blocks of W. 
            Utils.QuadWordFromBigEndian (expandedBuffer, 16, block); 
            SHA512Expand (expandedBuffer);
 
            /* Apply the SHA512 compression function */
            // We are trying to be smart here and avoid as many copies as we can
            // The perf gain with this method over the straightforward modify and shift
            // forward is >= 20%, so it's worth the pain 
            for (int j=0; j<80; ) {
                T1 = h + Sigma_1(e) + Ch(e,f,g) + _K[j] + expandedBuffer[j]; 
                ee = d + T1; 
                aa = T1 + Sigma_0(a) + Maj(a,b,c);
                j++; 

                T1 = g + Sigma_1(ee) + Ch(ee,e,f) + _K[j] + expandedBuffer[j];
                ff = c + T1;
                bb = T1 + Sigma_0(aa) + Maj(aa,a,b); 
                j++;
 
                T1 = f + Sigma_1(ff) + Ch(ff,ee,e) + _K[j] + expandedBuffer[j]; 
                gg = b + T1;
                cc = T1 + Sigma_0(bb) + Maj(bb,aa,a); 
                j++;

                T1 = e + Sigma_1(gg) + Ch(gg,ff,ee) + _K[j] + expandedBuffer[j];
                hh = a + T1; 
                dd = T1 + Sigma_0(cc) + Maj(cc,bb,aa);
                j++; 
 
                T1 = ee + Sigma_1(hh) + Ch(hh,gg,ff) + _K[j] + expandedBuffer[j];
                h = aa + T1; 
                d = T1 + Sigma_0(dd) + Maj(dd,cc,bb);
                j++;

                T1 = ff + Sigma_1(h) + Ch(h,hh,gg) + _K[j] + expandedBuffer[j]; 
                g = bb + T1;
                c = T1 + Sigma_0(d) + Maj(d,dd,cc); 
                j++; 

                T1 = gg + Sigma_1(g) + Ch(g,h,hh) + _K[j] + expandedBuffer[j]; 
                f = cc + T1;
                b = T1 + Sigma_0(c) + Maj(c,d,dd);
                j++;
 
                T1 = hh + Sigma_1(f) + Ch(f,g,h) + _K[j] + expandedBuffer[j];
                e = dd + T1; 
                a = T1 + Sigma_0(b) + Maj(b,c,d); 
                j++;
            } 

            state[0] += a;
            state[1] += b;
            state[2] += c; 
            state[3] += d;
            state[4] += e; 
            state[5] += f; 
            state[6] += g;
            state[7] += h; 
        }

        private static UInt64 RotateRight(UInt64 x, int n) {
            return (((x) >> (n)) | ((x) << (64-(n)))); 
        }
 
        private static UInt64 Ch(UInt64 x, UInt64 y, UInt64 z) { 
            return ((x & y) ^ ((x ^ 0xffffffffffffffff) & z));
        } 

        private static UInt64 Maj(UInt64 x, UInt64 y, UInt64 z) {
            return ((x & y) ^ (x & z) ^ (y & z));
        } 

        private static UInt64 Sigma_0(UInt64 x) { 
            return (RotateRight(x,28) ^ RotateRight(x,34) ^ RotateRight(x,39)); 
        }
 
        private static UInt64 Sigma_1(UInt64 x) {
            return (RotateRight(x,14) ^ RotateRight(x,18) ^ RotateRight(x,41));
        }
 
        private static UInt64 sigma_0(UInt64 x) {
            return (RotateRight(x,1) ^ RotateRight(x,8) ^ (x >> 7)); 
        } 

        private static UInt64 sigma_1(UInt64 x) { 
            return (RotateRight(x,19) ^ RotateRight(x,61) ^ (x >> 6));
        }

        /* This function creates W_16,...,W_79 according to the formula 
           W_j <- sigma_1(W_{j-2}) + W_{j-7} + sigma_0(W_{j-15}) + W_{j-16};
        */ 
 
        private static unsafe void SHA512Expand (UInt64* x)
        { 
            for (int i = 16; i < 80; i++) {
                x[i] = sigma_1(x[i-2]) + x[i-7] + sigma_0(x[i-15]) + x[i-16];
            }
        } 
    }
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// ==++== 
//
//   Copyright (c) Microsoft Corporation.  All rights reserved.
//
// ==--== 

// 
// SHA512Managed.cs 
//
// C# implementation of the proposed SHA-512 hash algorithm 
//

namespace System.Security.Cryptography {
    using System; 

    [System.Runtime.InteropServices.ComVisible(true)] 
    public class SHA512Managed : SHA512 
    {
        private byte[]   _buffer; 
        private ulong    _count; // Number of bytes in the hashed message
        private UInt64[] _stateSHA512;
        private UInt64[] _W;
 
        //
        // public constructors 
        // 

        public SHA512Managed() 
        {
            if (Utils.FipsAlgorithmPolicy == 1)
                throw new InvalidOperationException(Environment.GetResourceString("Cryptography_NonCompliantFIPSAlgorithm"));
 
            _stateSHA512 = new UInt64[8];
            _buffer = new byte[128]; 
            _W = new UInt64[80]; 

            InitializeState(); 
        }

        //
        // public methods 
        //
 
        public override void Initialize() { 
            InitializeState();
 
            // Zeroize potentially sensitive information.
            Array.Clear(_buffer, 0, _buffer.Length);
            Array.Clear(_W, 0, _W.Length);
        } 

        protected override void HashCore(byte[] rgb, int ibStart, int cbSize) { 
            _HashData(rgb, ibStart, cbSize); 
        }
 
        protected override byte[] HashFinal() {
            return _EndHash();
        }
 
        //
        // private methods 
        // 

        private void InitializeState() { 
            _count = 0;

            _stateSHA512[0] = 0x6a09e667f3bcc908;
            _stateSHA512[1] = 0xbb67ae8584caa73b; 
            _stateSHA512[2] = 0x3c6ef372fe94f82b;
            _stateSHA512[3] = 0xa54ff53a5f1d36f1; 
            _stateSHA512[4] = 0x510e527fade682d1; 
            _stateSHA512[5] = 0x9b05688c2b3e6c1f;
            _stateSHA512[6] = 0x1f83d9abfb41bd6b; 
            _stateSHA512[7] = 0x5be0cd19137e2179;
        }

        /* SHA512 block update operation. Continues an SHA message-digest 
           operation, processing another message block, and updating the
           context. 
           */ 

        private unsafe void _HashData(byte[] partIn, int ibStart, int cbSize) 
        {
            int bufferLen;
            int partInLen = cbSize;
            int partInBase = ibStart; 

            /* Compute length of buffer */ 
            bufferLen = (int) (_count & 0x7f); 

            /* Update number of bytes */ 
            _count += (ulong) partInLen;

            fixed (UInt64* stateSHA512 = _stateSHA512) {
                fixed (byte* buffer = _buffer) { 
                    fixed (UInt64* expandedBuffer = _W) {
                        if ((bufferLen > 0) && (bufferLen + partInLen >= 128)) { 
                            Buffer.InternalBlockCopy(partIn, partInBase, _buffer, bufferLen, 128 - bufferLen); 
                            partInBase += (128 - bufferLen);
                            partInLen -= (128 - bufferLen); 
                            SHATransform(expandedBuffer, stateSHA512, buffer);
                            bufferLen = 0;
                        }
 
                        /* Copy input to temporary buffer and hash */
                        while (partInLen >= 128) { 
                            Buffer.InternalBlockCopy(partIn, partInBase, _buffer, 0, 128); 
                            partInBase += 128;
                            partInLen -= 128; 
                            SHATransform(expandedBuffer, stateSHA512, buffer);
                        }

                        if (partInLen > 0) { 
                            Buffer.InternalBlockCopy(partIn, partInBase, _buffer, bufferLen, partInLen);
                        } 
                    } 
                }
            } 
        }

        /* SHA512 finalization. Ends an SHA512 message-digest operation, writing
           the message digest. 
           */
 
        private byte[] _EndHash() 
        {
            byte[]         pad; 
            int            padLen;
            ulong          bitCount;
            byte[]         hash = new byte[64]; // HashSizeValue = 512
 
            /* Compute padding: 80 00 00 ... 00 00 
             */ 
 
            padLen = 128 - (int)(_count & 0x7f);
            if (padLen <= 16) 
                padLen += 128;

            pad = new byte[padLen];
            pad[0] = 0x80; 

            //  Convert count to bit count 
            bitCount = _count * 8; 

            // If we ever have UInt128 for bitCount, then these need to be uncommented. 
            // Note that C# only looks at the low 6 bits of the shift value for ulongs,
            // so >>0 and >>64 are equal!

            //pad[padLen-16] = (byte) ((bitCount >> 120) & 0xff); 
            //pad[padLen-15] = (byte) ((bitCount >> 112) & 0xff);
            //pad[padLen-14] = (byte) ((bitCount >> 104) & 0xff); 
            //pad[padLen-13] = (byte) ((bitCount >> 96) & 0xff); 
            //pad[padLen-12] = (byte) ((bitCount >> 88) & 0xff);
            //pad[padLen-11] = (byte) ((bitCount >> 80) & 0xff); 
            //pad[padLen-10] = (byte) ((bitCount >> 72) & 0xff);
            //pad[padLen-9] = (byte) ((bitCount >> 64) & 0xff);
            pad[padLen-8] = (byte) ((bitCount >> 56) & 0xff);
            pad[padLen-7] = (byte) ((bitCount >> 48) & 0xff); 
            pad[padLen-6] = (byte) ((bitCount >> 40) & 0xff);
            pad[padLen-5] = (byte) ((bitCount >> 32) & 0xff); 
            pad[padLen-4] = (byte) ((bitCount >> 24) & 0xff); 
            pad[padLen-3] = (byte) ((bitCount >> 16) & 0xff);
            pad[padLen-2] = (byte) ((bitCount >> 8) & 0xff); 
            pad[padLen-1] = (byte) ((bitCount >> 0) & 0xff);

            /* Digest padding */
            _HashData(pad, 0, pad.Length); 

            /* Store digest */ 
            Utils.QuadWordToBigEndian (hash, _stateSHA512, 8); 

            HashValue = hash; 
            return hash;
        }

        private readonly static UInt64[] _K = { 
            0x428a2f98d728ae22, 0x7137449123ef65cd, 0xb5c0fbcfec4d3b2f, 0xe9b5dba58189dbbc,
            0x3956c25bf348b538, 0x59f111f1b605d019, 0x923f82a4af194f9b, 0xab1c5ed5da6d8118, 
            0xd807aa98a3030242, 0x12835b0145706fbe, 0x243185be4ee4b28c, 0x550c7dc3d5ffb4e2, 
            0x72be5d74f27b896f, 0x80deb1fe3b1696b1, 0x9bdc06a725c71235, 0xc19bf174cf692694,
            0xe49b69c19ef14ad2, 0xefbe4786384f25e3, 0x0fc19dc68b8cd5b5, 0x240ca1cc77ac9c65, 
            0x2de92c6f592b0275, 0x4a7484aa6ea6e483, 0x5cb0a9dcbd41fbd4, 0x76f988da831153b5,
            0x983e5152ee66dfab, 0xa831c66d2db43210, 0xb00327c898fb213f, 0xbf597fc7beef0ee4,
            0xc6e00bf33da88fc2, 0xd5a79147930aa725, 0x06ca6351e003826f, 0x142929670a0e6e70,
            0x27b70a8546d22ffc, 0x2e1b21385c26c926, 0x4d2c6dfc5ac42aed, 0x53380d139d95b3df, 
            0x650a73548baf63de, 0x766a0abb3c77b2a8, 0x81c2c92e47edaee6, 0x92722c851482353b,
            0xa2bfe8a14cf10364, 0xa81a664bbc423001, 0xc24b8b70d0f89791, 0xc76c51a30654be30, 
            0xd192e819d6ef5218, 0xd69906245565a910, 0xf40e35855771202a, 0x106aa07032bbd1b8, 
            0x19a4c116b8d2d0c8, 0x1e376c085141ab53, 0x2748774cdf8eeb99, 0x34b0bcb5e19b48a8,
            0x391c0cb3c5c95a63, 0x4ed8aa4ae3418acb, 0x5b9cca4f7763e373, 0x682e6ff3d6b2b8a3, 
            0x748f82ee5defb2fc, 0x78a5636f43172f60, 0x84c87814a1f0ab72, 0x8cc702081a6439ec,
            0x90befffa23631e28, 0xa4506cebde82bde9, 0xbef9a3f7b2c67915, 0xc67178f2e372532b,
            0xca273eceea26619c, 0xd186b8c721c0c207, 0xeada7dd6cde0eb1e, 0xf57d4f7fee6ed178,
            0x06f067aa72176fba, 0x0a637dc5a2c898a6, 0x113f9804bef90dae, 0x1b710b35131c471b, 
            0x28db77f523047d84, 0x32caab7b40c72493, 0x3c9ebe0a15c9bebc, 0x431d67c49c100d4c,
            0x4cc5d4becb3e42b6, 0x597f299cfc657e2a, 0x5fcb6fab3ad6faec, 0x6c44198c4a475817, 
        }; 

        private static unsafe void SHATransform (UInt64* expandedBuffer, UInt64* state, byte* block) 
        {
            UInt64 a, b, c, d, e, f, g, h;
            UInt64 aa, bb, cc, dd, ee, ff, hh, gg;
            UInt64 T1; 

            a = state[0]; 
            b = state[1]; 
            c = state[2];
            d = state[3]; 
            e = state[4];
            f = state[5];
            g = state[6];
            h = state[7]; 

            // fill in the first 16 blocks of W. 
            Utils.QuadWordFromBigEndian (expandedBuffer, 16, block); 
            SHA512Expand (expandedBuffer);
 
            /* Apply the SHA512 compression function */
            // We are trying to be smart here and avoid as many copies as we can
            // The perf gain with this method over the straightforward modify and shift
            // forward is >= 20%, so it's worth the pain 
            for (int j=0; j<80; ) {
                T1 = h + Sigma_1(e) + Ch(e,f,g) + _K[j] + expandedBuffer[j]; 
                ee = d + T1; 
                aa = T1 + Sigma_0(a) + Maj(a,b,c);
                j++; 

                T1 = g + Sigma_1(ee) + Ch(ee,e,f) + _K[j] + expandedBuffer[j];
                ff = c + T1;
                bb = T1 + Sigma_0(aa) + Maj(aa,a,b); 
                j++;
 
                T1 = f + Sigma_1(ff) + Ch(ff,ee,e) + _K[j] + expandedBuffer[j]; 
                gg = b + T1;
                cc = T1 + Sigma_0(bb) + Maj(bb,aa,a); 
                j++;

                T1 = e + Sigma_1(gg) + Ch(gg,ff,ee) + _K[j] + expandedBuffer[j];
                hh = a + T1; 
                dd = T1 + Sigma_0(cc) + Maj(cc,bb,aa);
                j++; 
 
                T1 = ee + Sigma_1(hh) + Ch(hh,gg,ff) + _K[j] + expandedBuffer[j];
                h = aa + T1; 
                d = T1 + Sigma_0(dd) + Maj(dd,cc,bb);
                j++;

                T1 = ff + Sigma_1(h) + Ch(h,hh,gg) + _K[j] + expandedBuffer[j]; 
                g = bb + T1;
                c = T1 + Sigma_0(d) + Maj(d,dd,cc); 
                j++; 

                T1 = gg + Sigma_1(g) + Ch(g,h,hh) + _K[j] + expandedBuffer[j]; 
                f = cc + T1;
                b = T1 + Sigma_0(c) + Maj(c,d,dd);
                j++;
 
                T1 = hh + Sigma_1(f) + Ch(f,g,h) + _K[j] + expandedBuffer[j];
                e = dd + T1; 
                a = T1 + Sigma_0(b) + Maj(b,c,d); 
                j++;
            } 

            state[0] += a;
            state[1] += b;
            state[2] += c; 
            state[3] += d;
            state[4] += e; 
            state[5] += f; 
            state[6] += g;
            state[7] += h; 
        }

        private static UInt64 RotateRight(UInt64 x, int n) {
            return (((x) >> (n)) | ((x) << (64-(n)))); 
        }
 
        private static UInt64 Ch(UInt64 x, UInt64 y, UInt64 z) { 
            return ((x & y) ^ ((x ^ 0xffffffffffffffff) & z));
        } 

        private static UInt64 Maj(UInt64 x, UInt64 y, UInt64 z) {
            return ((x & y) ^ (x & z) ^ (y & z));
        } 

        private static UInt64 Sigma_0(UInt64 x) { 
            return (RotateRight(x,28) ^ RotateRight(x,34) ^ RotateRight(x,39)); 
        }
 
        private static UInt64 Sigma_1(UInt64 x) {
            return (RotateRight(x,14) ^ RotateRight(x,18) ^ RotateRight(x,41));
        }
 
        private static UInt64 sigma_0(UInt64 x) {
            return (RotateRight(x,1) ^ RotateRight(x,8) ^ (x >> 7)); 
        } 

        private static UInt64 sigma_1(UInt64 x) { 
            return (RotateRight(x,19) ^ RotateRight(x,61) ^ (x >> 6));
        }

        /* This function creates W_16,...,W_79 according to the formula 
           W_j <- sigma_1(W_{j-2}) + W_{j-7} + sigma_0(W_{j-15}) + W_{j-16};
        */ 
 
        private static unsafe void SHA512Expand (UInt64* x)
        { 
            for (int i = 16; i < 80; i++) {
                x[i] = sigma_1(x[i-2]) + x[i-7] + sigma_0(x[i-15]) + x[i-16];
            }
        } 
    }
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
                        

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