Java tutorial
package org.bouncycastle.crypto.digests; import org.bouncycastle.util.Memoable; /** * implementation of RIPEMD256. * <p> * <b>note:</b> this algorithm offers the same level of security as RIPEMD128. */ public class RIPEMD256Digest extends GeneralDigest { private static final int DIGEST_LENGTH = 32; private int H0, H1, H2, H3, H4, H5, H6, H7; // IV's private int[] X = new int[16]; private int xOff; /** * Standard constructor */ public RIPEMD256Digest() { reset(); } /** * Copy constructor. This will copy the state of the provided * message digest. */ public RIPEMD256Digest(RIPEMD256Digest t) { super(t); copyIn(t); } private void copyIn(RIPEMD256Digest t) { super.copyIn(t); H0 = t.H0; H1 = t.H1; H2 = t.H2; H3 = t.H3; H4 = t.H4; H5 = t.H5; H6 = t.H6; H7 = t.H7; System.arraycopy(t.X, 0, X, 0, t.X.length); xOff = t.xOff; } public String getAlgorithmName() { return "RIPEMD256"; } public int getDigestSize() { return DIGEST_LENGTH; } protected void processWord(byte[] in, int inOff) { X[xOff++] = (in[inOff] & 0xff) | ((in[inOff + 1] & 0xff) << 8) | ((in[inOff + 2] & 0xff) << 16) | ((in[inOff + 3] & 0xff) << 24); if (xOff == 16) { processBlock(); } } protected void processLength(long bitLength) { if (xOff > 14) { processBlock(); } X[14] = (int) (bitLength & 0xffffffff); X[15] = (int) (bitLength >>> 32); } private void unpackWord(int word, byte[] out, int outOff) { out[outOff] = (byte) word; out[outOff + 1] = (byte) (word >>> 8); out[outOff + 2] = (byte) (word >>> 16); out[outOff + 3] = (byte) (word >>> 24); } public int doFinal(byte[] out, int outOff) { finish(); unpackWord(H0, out, outOff); unpackWord(H1, out, outOff + 4); unpackWord(H2, out, outOff + 8); unpackWord(H3, out, outOff + 12); unpackWord(H4, out, outOff + 16); unpackWord(H5, out, outOff + 20); unpackWord(H6, out, outOff + 24); unpackWord(H7, out, outOff + 28); reset(); return DIGEST_LENGTH; } /** * reset the chaining variables to the IV values. */ public void reset() { super.reset(); H0 = 0x67452301; H1 = 0xefcdab89; H2 = 0x98badcfe; H3 = 0x10325476; H4 = 0x76543210; H5 = 0xFEDCBA98; H6 = 0x89ABCDEF; H7 = 0x01234567; xOff = 0; for (int i = 0; i != X.length; i++) { X[i] = 0; } } /* * rotate int x left n bits. */ private int RL(int x, int n) { return (x << n) | (x >>> (32 - n)); } /* * f1,f2,f3,f4 are the basic RIPEMD128 functions. */ /* * F */ private int f1(int x, int y, int z) { return x ^ y ^ z; } /* * G */ private int f2(int x, int y, int z) { return (x & y) | (~x & z); } /* * H */ private int f3(int x, int y, int z) { return (x | ~y) ^ z; } /* * I */ private int f4(int x, int y, int z) { return (x & z) | (y & ~z); } private int F1(int a, int b, int c, int d, int x, int s) { return RL(a + f1(b, c, d) + x, s); } private int F2(int a, int b, int c, int d, int x, int s) { return RL(a + f2(b, c, d) + x + 0x5a827999, s); } private int F3(int a, int b, int c, int d, int x, int s) { return RL(a + f3(b, c, d) + x + 0x6ed9eba1, s); } private int F4(int a, int b, int c, int d, int x, int s) { return RL(a + f4(b, c, d) + x + 0x8f1bbcdc, s); } private int FF1(int a, int b, int c, int d, int x, int s) { return RL(a + f1(b, c, d) + x, s); } private int FF2(int a, int b, int c, int d, int x, int s) { return RL(a + f2(b, c, d) + x + 0x6d703ef3, s); } private int FF3(int a, int b, int c, int d, int x, int s) { return RL(a + f3(b, c, d) + x + 0x5c4dd124, s); } private int FF4(int a, int b, int c, int d, int x, int s) { return RL(a + f4(b, c, d) + x + 0x50a28be6, s); } protected void processBlock() { int a, aa; int b, bb; int c, cc; int d, dd; int t; a = H0; b = H1; c = H2; d = H3; aa = H4; bb = H5; cc = H6; dd = H7; // // Round 1 // a = F1(a, b, c, d, X[0], 11); d = F1(d, a, b, c, X[1], 14); c = F1(c, d, a, b, X[2], 15); b = F1(b, c, d, a, X[3], 12); a = F1(a, b, c, d, X[4], 5); d = F1(d, a, b, c, X[5], 8); c = F1(c, d, a, b, X[6], 7); b = F1(b, c, d, a, X[7], 9); a = F1(a, b, c, d, X[8], 11); d = F1(d, a, b, c, X[9], 13); c = F1(c, d, a, b, X[10], 14); b = F1(b, c, d, a, X[11], 15); a = F1(a, b, c, d, X[12], 6); d = F1(d, a, b, c, X[13], 7); c = F1(c, d, a, b, X[14], 9); b = F1(b, c, d, a, X[15], 8); aa = FF4(aa, bb, cc, dd, X[5], 8); dd = FF4(dd, aa, bb, cc, X[14], 9); cc = FF4(cc, dd, aa, bb, X[7], 9); bb = FF4(bb, cc, dd, aa, X[0], 11); aa = FF4(aa, bb, cc, dd, X[9], 13); dd = FF4(dd, aa, bb, cc, X[2], 15); cc = FF4(cc, dd, aa, bb, X[11], 15); bb = FF4(bb, cc, dd, aa, X[4], 5); aa = FF4(aa, bb, cc, dd, X[13], 7); dd = FF4(dd, aa, bb, cc, X[6], 7); cc = FF4(cc, dd, aa, bb, X[15], 8); bb = FF4(bb, cc, dd, aa, X[8], 11); aa = FF4(aa, bb, cc, dd, X[1], 14); dd = FF4(dd, aa, bb, cc, X[10], 14); cc = FF4(cc, dd, aa, bb, X[3], 12); bb = FF4(bb, cc, dd, aa, X[12], 6); t = a; a = aa; aa = t; // // Round 2 // a = F2(a, b, c, d, X[7], 7); d = F2(d, a, b, c, X[4], 6); c = F2(c, d, a, b, X[13], 8); b = F2(b, c, d, a, X[1], 13); a = F2(a, b, c, d, X[10], 11); d = F2(d, a, b, c, X[6], 9); c = F2(c, d, a, b, X[15], 7); b = F2(b, c, d, a, X[3], 15); a = F2(a, b, c, d, X[12], 7); d = F2(d, a, b, c, X[0], 12); c = F2(c, d, a, b, X[9], 15); b = F2(b, c, d, a, X[5], 9); a = F2(a, b, c, d, X[2], 11); d = F2(d, a, b, c, X[14], 7); c = F2(c, d, a, b, X[11], 13); b = F2(b, c, d, a, X[8], 12); aa = FF3(aa, bb, cc, dd, X[6], 9); dd = FF3(dd, aa, bb, cc, X[11], 13); cc = FF3(cc, dd, aa, bb, X[3], 15); bb = FF3(bb, cc, dd, aa, X[7], 7); aa = FF3(aa, bb, cc, dd, X[0], 12); dd = FF3(dd, aa, bb, cc, X[13], 8); cc = FF3(cc, dd, aa, bb, X[5], 9); bb = FF3(bb, cc, dd, aa, X[10], 11); aa = FF3(aa, bb, cc, dd, X[14], 7); dd = FF3(dd, aa, bb, cc, X[15], 7); cc = FF3(cc, dd, aa, bb, X[8], 12); bb = FF3(bb, cc, dd, aa, X[12], 7); aa = FF3(aa, bb, cc, dd, X[4], 6); dd = FF3(dd, aa, bb, cc, X[9], 15); cc = FF3(cc, dd, aa, bb, X[1], 13); bb = FF3(bb, cc, dd, aa, X[2], 11); t = b; b = bb; bb = t; // // Round 3 // a = F3(a, b, c, d, X[3], 11); d = F3(d, a, b, c, X[10], 13); c = F3(c, d, a, b, X[14], 6); b = F3(b, c, d, a, X[4], 7); a = F3(a, b, c, d, X[9], 14); d = F3(d, a, b, c, X[15], 9); c = F3(c, d, a, b, X[8], 13); b = F3(b, c, d, a, X[1], 15); a = F3(a, b, c, d, X[2], 14); d = F3(d, a, b, c, X[7], 8); c = F3(c, d, a, b, X[0], 13); b = F3(b, c, d, a, X[6], 6); a = F3(a, b, c, d, X[13], 5); d = F3(d, a, b, c, X[11], 12); c = F3(c, d, a, b, X[5], 7); b = F3(b, c, d, a, X[12], 5); aa = FF2(aa, bb, cc, dd, X[15], 9); dd = FF2(dd, aa, bb, cc, X[5], 7); cc = FF2(cc, dd, aa, bb, X[1], 15); bb = FF2(bb, cc, dd, aa, X[3], 11); aa = FF2(aa, bb, cc, dd, X[7], 8); dd = FF2(dd, aa, bb, cc, X[14], 6); cc = FF2(cc, dd, aa, bb, X[6], 6); bb = FF2(bb, cc, dd, aa, X[9], 14); aa = FF2(aa, bb, cc, dd, X[11], 12); dd = FF2(dd, aa, bb, cc, X[8], 13); cc = FF2(cc, dd, aa, bb, X[12], 5); bb = FF2(bb, cc, dd, aa, X[2], 14); aa = FF2(aa, bb, cc, dd, X[10], 13); dd = FF2(dd, aa, bb, cc, X[0], 13); cc = FF2(cc, dd, aa, bb, X[4], 7); bb = FF2(bb, cc, dd, aa, X[13], 5); t = c; c = cc; cc = t; // // Round 4 // a = F4(a, b, c, d, X[1], 11); d = F4(d, a, b, c, X[9], 12); c = F4(c, d, a, b, X[11], 14); b = F4(b, c, d, a, X[10], 15); a = F4(a, b, c, d, X[0], 14); d = F4(d, a, b, c, X[8], 15); c = F4(c, d, a, b, X[12], 9); b = F4(b, c, d, a, X[4], 8); a = F4(a, b, c, d, X[13], 9); d = F4(d, a, b, c, X[3], 14); c = F4(c, d, a, b, X[7], 5); b = F4(b, c, d, a, X[15], 6); a = F4(a, b, c, d, X[14], 8); d = F4(d, a, b, c, X[5], 6); c = F4(c, d, a, b, X[6], 5); b = F4(b, c, d, a, X[2], 12); aa = FF1(aa, bb, cc, dd, X[8], 15); dd = FF1(dd, aa, bb, cc, X[6], 5); cc = FF1(cc, dd, aa, bb, X[4], 8); bb = FF1(bb, cc, dd, aa, X[1], 11); aa = FF1(aa, bb, cc, dd, X[3], 14); dd = FF1(dd, aa, bb, cc, X[11], 14); cc = FF1(cc, dd, aa, bb, X[15], 6); bb = FF1(bb, cc, dd, aa, X[0], 14); aa = FF1(aa, bb, cc, dd, X[5], 6); dd = FF1(dd, aa, bb, cc, X[12], 9); cc = FF1(cc, dd, aa, bb, X[2], 12); bb = FF1(bb, cc, dd, aa, X[13], 9); aa = FF1(aa, bb, cc, dd, X[9], 12); dd = FF1(dd, aa, bb, cc, X[7], 5); cc = FF1(cc, dd, aa, bb, X[10], 15); bb = FF1(bb, cc, dd, aa, X[14], 8); t = d; d = dd; dd = t; H0 += a; H1 += b; H2 += c; H3 += d; H4 += aa; H5 += bb; H6 += cc; H7 += dd; // // reset the offset and clean out the word buffer. // xOff = 0; for (int i = 0; i != X.length; i++) { X[i] = 0; } } public Memoable copy() { return new RIPEMD256Digest(this); } public void reset(Memoable other) { RIPEMD256Digest d = (RIPEMD256Digest) other; copyIn(d); } }