package org.bouncycastle.crypto.digests;


implementation of MD5 as outlined in "Handbook of Applied Cryptography", pages 346 - 347.
/** * implementation of MD5 as outlined in "Handbook of Applied Cryptography", pages 346 - 347. */
public class MD5Digest extends GeneralDigest { private static final int DIGEST_LENGTH = 16; private int H1, H2, H3, H4; // IV's private int[] X = new int[16]; private int xOff;
Standard constructor
/** * Standard constructor */
public MD5Digest() { reset(); }
Copy constructor. This will copy the state of the provided message digest.
/** * Copy constructor. This will copy the state of the provided * message digest. */
public MD5Digest(MD5Digest t) { super(t); H1 = t.H1; H2 = t.H2; H3 = t.H3; H4 = t.H4; System.arraycopy(t.X, 0, X, 0, t.X.length); xOff = t.xOff; } public String getAlgorithmName() { return "MD5"; } 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(H1, out, outOff); unpackWord(H2, out, outOff + 4); unpackWord(H3, out, outOff + 8); unpackWord(H4, out, outOff + 12); reset(); return DIGEST_LENGTH; }
reset the chaining variables to the IV values.
/** * reset the chaining variables to the IV values. */
public void reset() { super.reset(); H1 = 0x67452301; H2 = 0xefcdab89; H3 = 0x98badcfe; H4 = 0x10325476; xOff = 0; for (int i = 0; i != X.length; i++) { X[i] = 0; } } // // round 1 left rotates // private static final int S11 = 7; private static final int S12 = 12; private static final int S13 = 17; private static final int S14 = 22; // // round 2 left rotates // private static final int S21 = 5; private static final int S22 = 9; private static final int S23 = 14; private static final int S24 = 20; // // round 3 left rotates // private static final int S31 = 4; private static final int S32 = 11; private static final int S33 = 16; private static final int S34 = 23; // // round 4 left rotates // private static final int S41 = 6; private static final int S42 = 10; private static final int S43 = 15; private static final int S44 = 21; /* * rotate int x left n bits. */ private int rotateLeft( int x, int n) { return (x << n) | (x >>> (32 - n)); } /* * F, G, H and I are the basic MD5 functions. */ private int F( int u, int v, int w) { return (u & v) | (~u & w); } private int G( int u, int v, int w) { return (u & w) | (v & ~w); } private int H( int u, int v, int w) { return u ^ v ^ w; } private int K( int u, int v, int w) { return v ^ (u | ~w); } protected void processBlock() { int a = H1; int b = H2; int c = H3; int d = H4; // // Round 1 - F cycle, 16 times. // a = rotateLeft(a + F(b, c, d) + X[ 0] + 0xd76aa478, S11) + b; d = rotateLeft(d + F(a, b, c) + X[ 1] + 0xe8c7b756, S12) + a; c = rotateLeft(c + F(d, a, b) + X[ 2] + 0x242070db, S13) + d; b = rotateLeft(b + F(c, d, a) + X[ 3] + 0xc1bdceee, S14) + c; a = rotateLeft(a + F(b, c, d) + X[ 4] + 0xf57c0faf, S11) + b; d = rotateLeft(d + F(a, b, c) + X[ 5] + 0x4787c62a, S12) + a; c = rotateLeft(c + F(d, a, b) + X[ 6] + 0xa8304613, S13) + d; b = rotateLeft(b + F(c, d, a) + X[ 7] + 0xfd469501, S14) + c; a = rotateLeft(a + F(b, c, d) + X[ 8] + 0x698098d8, S11) + b; d = rotateLeft(d + F(a, b, c) + X[ 9] + 0x8b44f7af, S12) + a; c = rotateLeft(c + F(d, a, b) + X[10] + 0xffff5bb1, S13) + d; b = rotateLeft(b + F(c, d, a) + X[11] + 0x895cd7be, S14) + c; a = rotateLeft(a + F(b, c, d) + X[12] + 0x6b901122, S11) + b; d = rotateLeft(d + F(a, b, c) + X[13] + 0xfd987193, S12) + a; c = rotateLeft(c + F(d, a, b) + X[14] + 0xa679438e, S13) + d; b = rotateLeft(b + F(c, d, a) + X[15] + 0x49b40821, S14) + c; // // Round 2 - G cycle, 16 times. // a = rotateLeft(a + G(b, c, d) + X[ 1] + 0xf61e2562, S21) + b; d = rotateLeft(d + G(a, b, c) + X[ 6] + 0xc040b340, S22) + a; c = rotateLeft(c + G(d, a, b) + X[11] + 0x265e5a51, S23) + d; b = rotateLeft(b + G(c, d, a) + X[ 0] + 0xe9b6c7aa, S24) + c; a = rotateLeft(a + G(b, c, d) + X[ 5] + 0xd62f105d, S21) + b; d = rotateLeft(d + G(a, b, c) + X[10] + 0x02441453, S22) + a; c = rotateLeft(c + G(d, a, b) + X[15] + 0xd8a1e681, S23) + d; b = rotateLeft(b + G(c, d, a) + X[ 4] + 0xe7d3fbc8, S24) + c; a = rotateLeft(a + G(b, c, d) + X[ 9] + 0x21e1cde6, S21) + b; d = rotateLeft(d + G(a, b, c) + X[14] + 0xc33707d6, S22) + a; c = rotateLeft(c + G(d, a, b) + X[ 3] + 0xf4d50d87, S23) + d; b = rotateLeft(b + G(c, d, a) + X[ 8] + 0x455a14ed, S24) + c; a = rotateLeft(a + G(b, c, d) + X[13] + 0xa9e3e905, S21) + b; d = rotateLeft(d + G(a, b, c) + X[ 2] + 0xfcefa3f8, S22) + a; c = rotateLeft(c + G(d, a, b) + X[ 7] + 0x676f02d9, S23) + d; b = rotateLeft(b + G(c, d, a) + X[12] + 0x8d2a4c8a, S24) + c; // // Round 3 - H cycle, 16 times. // a = rotateLeft(a + H(b, c, d) + X[ 5] + 0xfffa3942, S31) + b; d = rotateLeft(d + H(a, b, c) + X[ 8] + 0x8771f681, S32) + a; c = rotateLeft(c + H(d, a, b) + X[11] + 0x6d9d6122, S33) + d; b = rotateLeft(b + H(c, d, a) + X[14] + 0xfde5380c, S34) + c; a = rotateLeft(a + H(b, c, d) + X[ 1] + 0xa4beea44, S31) + b; d = rotateLeft(d + H(a, b, c) + X[ 4] + 0x4bdecfa9, S32) + a; c = rotateLeft(c + H(d, a, b) + X[ 7] + 0xf6bb4b60, S33) + d; b = rotateLeft(b + H(c, d, a) + X[10] + 0xbebfbc70, S34) + c; a = rotateLeft(a + H(b, c, d) + X[13] + 0x289b7ec6, S31) + b; d = rotateLeft(d + H(a, b, c) + X[ 0] + 0xeaa127fa, S32) + a; c = rotateLeft(c + H(d, a, b) + X[ 3] + 0xd4ef3085, S33) + d; b = rotateLeft(b + H(c, d, a) + X[ 6] + 0x04881d05, S34) + c; a = rotateLeft(a + H(b, c, d) + X[ 9] + 0xd9d4d039, S31) + b; d = rotateLeft(d + H(a, b, c) + X[12] + 0xe6db99e5, S32) + a; c = rotateLeft(c + H(d, a, b) + X[15] + 0x1fa27cf8, S33) + d; b = rotateLeft(b + H(c, d, a) + X[ 2] + 0xc4ac5665, S34) + c; // // Round 4 - K cycle, 16 times. // a = rotateLeft(a + K(b, c, d) + X[ 0] + 0xf4292244, S41) + b; d = rotateLeft(d + K(a, b, c) + X[ 7] + 0x432aff97, S42) + a; c = rotateLeft(c + K(d, a, b) + X[14] + 0xab9423a7, S43) + d; b = rotateLeft(b + K(c, d, a) + X[ 5] + 0xfc93a039, S44) + c; a = rotateLeft(a + K(b, c, d) + X[12] + 0x655b59c3, S41) + b; d = rotateLeft(d + K(a, b, c) + X[ 3] + 0x8f0ccc92, S42) + a; c = rotateLeft(c + K(d, a, b) + X[10] + 0xffeff47d, S43) + d; b = rotateLeft(b + K(c, d, a) + X[ 1] + 0x85845dd1, S44) + c; a = rotateLeft(a + K(b, c, d) + X[ 8] + 0x6fa87e4f, S41) + b; d = rotateLeft(d + K(a, b, c) + X[15] + 0xfe2ce6e0, S42) + a; c = rotateLeft(c + K(d, a, b) + X[ 6] + 0xa3014314, S43) + d; b = rotateLeft(b + K(c, d, a) + X[13] + 0x4e0811a1, S44) + c; a = rotateLeft(a + K(b, c, d) + X[ 4] + 0xf7537e82, S41) + b; d = rotateLeft(d + K(a, b, c) + X[11] + 0xbd3af235, S42) + a; c = rotateLeft(c + K(d, a, b) + X[ 2] + 0x2ad7d2bb, S43) + d; b = rotateLeft(b + K(c, d, a) + X[ 9] + 0xeb86d391, S44) + c; H1 += a; H2 += b; H3 += c; H4 += d; // // reset the offset and clean out the word buffer. // xOff = 0; for (int i = 0; i != X.length; i++) { X[i] = 0; } } }