package org.bouncycastle.crypto.digests;import org.bouncycastle.crypto.*;import org.bouncycastle.crypto.params.KeyParameter;import org.bouncycastle.crypto.params.ParametersWithSBox;import org.bouncycastle.crypto.engines.GOST28147Engine;/** * implementation of GOST R 34.11-94 */public class GOST3411Digest    implements ExtendedDigest{    private static final int    DIGEST_LENGTH = 32;    private byte[]   H = new byte[32], L = new byte[32],                     M = new byte[32], Sum = new byte[32];    private byte[][] C = new byte[4][32];    private byte[]  xBuf = new byte[32];    private int  xBufOff;    private long byteCount;        private BlockCipher cipher = new GOST28147Engine();    /**     * Standard constructor     */    public GOST3411Digest()    {        cipher.init(true, new ParametersWithSBox(null, GOST28147Engine.getSBox("D-A")));                reset();    }    /**     * Copy constructor.  This will copy the state of the provided     * message digest.     */    public GOST3411Digest(GOST3411Digest t)    {        cipher.init(true, new ParametersWithSBox(null, GOST28147Engine.getSBox("D-A")));                reset();        System.arraycopy(t.H, 0, this.H, 0, t.H.length);        System.arraycopy(t.L, 0, this.L, 0, t.L.length);        System.arraycopy(t.M, 0, this.M, 0, t.M.length);        System.arraycopy(t.Sum, 0, this.Sum, 0, t.Sum.length);        System.arraycopy(t.C[1], 0, this.C[1], 0, t.C[1].length);        System.arraycopy(t.C[2], 0, this.C[2], 0, t.C[2].length);        System.arraycopy(t.C[3], 0, this.C[3], 0, t.C[3].length);        System.arraycopy(t.xBuf, 0, this.xBuf, 0, t.xBuf.length);                this.xBufOff = t.xBufOff;        this.byteCount = t.byteCount;    }    public String getAlgorithmName()    {        return "GOST3411";    }    public int getDigestSize()    {        return DIGEST_LENGTH;    }    public void update(byte in)    {        xBuf[xBufOff++] = in;        if (xBufOff == xBuf.length)        {            sumByteArray(xBuf); // calc sum M            processBlock(xBuf, 0);            xBufOff = 0;        }        byteCount++;    }    public void update(byte[] in, int inOff, int len)    {        while ((xBufOff != 0) && (len > 0))        {            update(in[inOff]);            inOff++;            len--;        }        while (len > xBuf.length)        {            System.arraycopy(in, inOff, xBuf, 0, xBuf.length);            sumByteArray(xBuf); // calc sum M            processBlock(xBuf, 0);            inOff += xBuf.length;            len -= xBuf.length;            byteCount += xBuf.length;        }        // load in the remainder.        while (len > 0)        {            update(in[inOff]);            inOff++;            len--;        }    }    // (i + 1 + 4(k - 1)) = 8i + k      i = 0-3, k = 1-8    private byte[] K = new byte[32];    private byte[] P(byte[] in)    {        for(int k = 0; k < 8; k++)        {            K[0 + 4*k] = in[ 0 + k];            K[1 + 4*k] = in[ 8 + k];            K[2 + 4*k] = in[16 + k];            K[3 + 4*k] = in[24 + k];        }        return K;    }    //A (x) = (x0 ^ x1) || x3 || x2 || x1    byte[] a = new byte[8];    private byte[] A(byte[] in)    {        for(int j=0; j<8; j++)        {            a[j]=(byte)(in[j] ^ in[j+8]);        }        System.arraycopy(in, 8, in, 0, 24);        System.arraycopy(a, 0, in, 24, 8);        return in;    }    //Encrypt function, ECB mode    private void E(byte[] key, byte[] s, int sOff, byte[] in, int inOff)    {        cipher.init(true, new KeyParameter(key));                cipher.processBlock(in, inOff, s, sOff);    }    // (in:) n16||..||n1 ==> (out:) n1^n2^n3^n4^n13^n16||n16||..||n2    short[] wS = new short[16], w_S = new short[16];    private void fw(byte[] in)    {        cpyBytesToShort(in, wS);        w_S[15] = (short)(wS[0] ^ wS[1] ^ wS[2] ^ wS[3] ^ wS[12] ^ wS[15]);        for (int i = 14; i >= 0; i--)        {            w_S[i] = wS[i+1];        }        cpyShortToBytes(w_S, in);    }    // block processing    byte[] S = new byte[32];    byte[] U = new byte[32], V = new byte[32], W = new byte[32];    protected void processBlock(byte[] in, int inOff)    {        System.arraycopy(in, inOff, M, 0, 32);        //key step 1        int i=0;        // H = h3 || h2 || h1 || h0        // S = s3 || s2 || s1 || s0        System.arraycopy(H, 0, U, 0, 32);        System.arraycopy(M, 0, V, 0, 32);        for (int j=0; j<32; j++)        {            W[j] = (byte)(U[j]^V[j]);        }        // Encrypt gost28147-ECB        E(P(W), S, 0, H, 0); // s0 = EK0 [h0]        //keys step 2,3,4        for (i=1; i<4; i++)        {            byte[] tmpA = A(U);            for (int j=0; j<32; j++)            {                U[j] = (byte)(tmpA[j] ^ C[i][j]);            }            V = A(A(V));            for (int j=0; j<32; j++)            {                W[j] = (byte)(U[j]^V[j]);            }            // Encrypt gost28147-ECB            E(P(W), S, i * 8, H, i * 8); // si = EKi [hi]        }        // x(M, H) = y61(H^y(M^y12(S)))        for(int n = 0; n < 12; n++)        {            fw(S);        }        for(int n = 0; n < 32; n++)        {            S[n] = (byte)(S[n] ^ M[n]);        }        fw(S);        for(int n = 0; n < 32; n++)        {            S[n] = (byte)(H[n] ^ S[n]);        }        for(int n = 0; n < 61; n++)        {            fw(S);        }        for(int j=0; j < H.length; j++)        {            H[j] = S[j];        }    }    private void finish()    {        LongToBytes(byteCount * 8, L, 0); // get length into L (byteCount * 8 = bitCount)        while (xBufOff != 0)        {            update((byte)0);        }        processBlock(L, 0);        processBlock(Sum, 0);    }    public int doFinal(        byte[]  out,        int     outOff)    {        finish();        for(int i=0; i<H.length; i++)        {            out[i+outOff] = H[i];        }        reset();        return DIGEST_LENGTH;    }    /**     * reset the chaining variables to the IV values.     */    private static byte[]  C2 = {       0x00,(byte)0xFF,0x00,(byte)0xFF,0x00,(byte)0xFF,0x00,(byte)0xFF,       (byte)0xFF,0x00,(byte)0xFF,0x00,(byte)0xFF,0x00,(byte)0xFF,0x00,       0x00,(byte)0xFF,(byte)0xFF,0x00,(byte)0xFF,0x00,0x00,(byte)0xFF,       (byte)0xFF,0x00,0x00,0x00,(byte)0xFF,(byte)0xFF,0x00,(byte)0xFF};    public void reset()    {        byteCount = 0;        xBufOff = 0;        for(int i=0; i<H.length; i++)        {            H[i] = 0;  // start vector H        }        for(int i=0; i<L.length; i++)        {            L[i] = 0;        }        for(int i=0; i<M.length; i++)        {            M[i] = 0;        }        for(int i=0; i<C[1].length; i++)        {            C[1][i] = 0;  // real index C = +1 because index array with 0.        }        for(int i=0; i<C[3].length; i++)        {            C[3][i] = 0;        }        for(int i=0; i<Sum.length; i++)        {            Sum[i] = 0;        }        for(int i = 0; i < xBuf.length; i++)        {            xBuf[i] = 0;        }        System.arraycopy(C2, 0, C[2], 0, C2.length);    }    //  256 bitsblock modul -> (Sum + a mod (2^256))    private void sumByteArray(byte[] in)    {        int carry = 0;        for (int i = 0; i != Sum.length; i++)        {            int sum = (Sum[i] & 0xff) + (in[i] & 0xff) + carry;            Sum[i] = (byte)sum;            carry = sum >>> 8;        }    }    private void LongToBytes(long r, byte[] out, int outOff)    {        out[outOff + 7] = (byte)(r >> 56);        out[outOff + 6] = (byte)(r >> 48);        out[outOff + 5] = (byte)(r >> 40);        out[outOff + 4] = (byte)(r >> 32);        out[outOff + 3] = (byte)(r >> 24);        out[outOff + 2] = (byte)(r >> 16);        out[outOff + 1] = (byte)(r >> 8);        out[outOff] = (byte)r;    }    private void cpyBytesToShort(byte[] S, short[] wS)    {        for(int i=0; i<S.length/2; i++)        {            wS[i] = (short)(((S[i*2+1]<<8)&0xFF00)|(S[i*2]&0xFF));        }    }    private void cpyShortToBytes(short[] wS, byte[] S)    {        for(int i=0; i<S.length/2; i++)         {            S[i*2 + 1] = (byte)(wS[i] >> 8);            S[i*2] = (byte)wS[i];        }    }   public int getByteLength()    {      return 32;   }}