/*
* Copyright (c) 2000 - 2006 The Legion Of The Bouncy Castle (http://www.bouncycastle.org)
*
* 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.
*/
package org.bouncycastle.crypto.digests;
/**
* implementation of SHA-1 as outlined in "Handbook of Applied Cryptography", pages 346 - 349.
*
* It is interesting to ponder why the, apart from the extra IV, the other
* difference here from MD5 is the "endienness" of the word processing!
*/
public class SHA1Digest extends GeneralDigest {
private static final int DIGEST_LENGTH = 20;
private int H1, H2, H3, H4, H5;
private int[] X = new int[80];
private int xOff;
/**
* Standard constructor
*/
public SHA1Digest() {
reset();
}
/**
* Copy constructor. This will copy the state of the provided message digest.
*/
public SHA1Digest(SHA1Digest t) {
super(t);
H1 = t.H1;
H2 = t.H2;
H3 = t.H3;
H4 = t.H4;
H5 = t.H5;
System.arraycopy(t.X, 0, X, 0, t.X.length);
xOff = t.xOff;
}
public String getAlgorithmName() {
return "SHA-1";
}
public int getDigestSize() {
return DIGEST_LENGTH;
}
protected void processWord(byte[] in, int inOff) {
X[xOff++] = (in[inOff] & 0xff) << 24 | (in[inOff + 1] & 0xff) << 16 | (in[inOff + 2] & 0xff) << 8 | in[inOff + 3] & 0xff;
if (xOff == 16) {
processBlock();
}
}
private void unpackWord(int word, byte[] out, int outOff) {
out[outOff++] = (byte) (word >>> 24);
out[outOff++] = (byte) (word >>> 16);
out[outOff++] = (byte) (word >>> 8);
out[outOff++] = (byte) word;
}
protected void processLength(long bitLength) {
if (xOff > 14) {
processBlock();
}
X[14] = (int) (bitLength >>> 32);
X[15] = (int) (bitLength & 0xffffffff);
}
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);
unpackWord(H5, out, outOff + 16);
reset();
return DIGEST_LENGTH;
}
/**
* reset the chaining variables
*/
public void reset() {
super.reset();
H1 = 0x67452301;
H2 = 0xefcdab89;
H3 = 0x98badcfe;
H4 = 0x10325476;
H5 = 0xc3d2e1f0;
xOff = 0;
for (int i = 0; i != X.length; i++) {
X[i] = 0;
}
}
//
// Additive constants
//
private static final int Y1 = 0x5a827999;
private static final int Y2 = 0x6ed9eba1;
private static final int Y3 = 0x8f1bbcdc;
private static final int Y4 = 0xca62c1d6;
private int f(int u, int v, int w) {
return ((u & v) | ((~u) & w));
}
private int h(int u, int v, int w) {
return (u ^ v ^ w);
}
private int g(int u, int v, int w) {
return ((u & v) | (u & w) | (v & w));
}
protected void processBlock() {
//
// expand 16 word block into 80 word block.
//
for (int i = 16; i < 80; i++) {
int t = X[i - 3] ^ X[i - 8] ^ X[i - 14] ^ X[i - 16];
X[i] = t << 1 | t >>> 31;
}
//
// set up working variables.
//
int A = H1;
int B = H2;
int C = H3;
int D = H4;
int E = H5;
//
// round 1
//
int idx = 0;
for (int j = 0; j < 4; j++) {
// E = rotateLeft(A, 5) + f(B, C, D) + E + X[idx++] + Y1
// B = rotateLeft(B, 30)
E += (A << 5 | A >>> 27) + f(B, C, D) + X[idx++] + Y1;
B = B << 30 | B >>> 2;
D += (E << 5 | E >>> 27) + f(A, B, C) + X[idx++] + Y1;
A = A << 30 | A >>> 2;
C += (D << 5 | D >>> 27) + f(E, A, B) + X[idx++] + Y1;
E = E << 30 | E >>> 2;
B += (C << 5 | C >>> 27) + f(D, E, A) + X[idx++] + Y1;
D = D << 30 | D >>> 2;
A += (B << 5 | B >>> 27) + f(C, D, E) + X[idx++] + Y1;
C = C << 30 | C >>> 2;
}
//
// round 2
//
for (int j = 0; j < 4; j++) {
// E = rotateLeft(A, 5) + h(B, C, D) + E + X[idx++] + Y2
// B = rotateLeft(B, 30)
E += (A << 5 | A >>> 27) + h(B, C, D) + X[idx++] + Y2;
B = B << 30 | B >>> 2;
D += (E << 5 | E >>> 27) + h(A, B, C) + X[idx++] + Y2;
A = A << 30 | A >>> 2;
C += (D << 5 | D >>> 27) + h(E, A, B) + X[idx++] + Y2;
E = E << 30 | E >>> 2;
B += (C << 5 | C >>> 27) + h(D, E, A) + X[idx++] + Y2;
D = D << 30 | D >>> 2;
A += (B << 5 | B >>> 27) + h(C, D, E) + X[idx++] + Y2;
C = C << 30 | C >>> 2;
}
//
// round 3
//
for (int j = 0; j < 4; j++) {
// E = rotateLeft(A, 5) + g(B, C, D) + E + X[idx++] + Y3
// B = rotateLeft(B, 30)
E += (A << 5 | A >>> 27) + g(B, C, D) + X[idx++] + Y3;
B = B << 30 | B >>> 2;
D += (E << 5 | E >>> 27) + g(A, B, C) + X[idx++] + Y3;
A = A << 30 | A >>> 2;
C += (D << 5 | D >>> 27) + g(E, A, B) + X[idx++] + Y3;
E = E << 30 | E >>> 2;
B += (C << 5 | C >>> 27) + g(D, E, A) + X[idx++] + Y3;
D = D << 30 | D >>> 2;
A += (B << 5 | B >>> 27) + g(C, D, E) + X[idx++] + Y3;
C = C << 30 | C >>> 2;
}
//
// round 4
//
for (int j = 0; j <= 3; j++) {
// E = rotateLeft(A, 5) + h(B, C, D) + E + X[idx++] + Y4
// B = rotateLeft(B, 30)
E += (A << 5 | A >>> 27) + h(B, C, D) + X[idx++] + Y4;
B = B << 30 | B >>> 2;
D += (E << 5 | E >>> 27) + h(A, B, C) + X[idx++] + Y4;
A = A << 30 | A >>> 2;
C += (D << 5 | D >>> 27) + h(E, A, B) + X[idx++] + Y4;
E = E << 30 | E >>> 2;
B += (C << 5 | C >>> 27) + h(D, E, A) + X[idx++] + Y4;
D = D << 30 | D >>> 2;
A += (B << 5 | B >>> 27) + h(C, D, E) + X[idx++] + Y4;
C = C << 30 | C >>> 2;
}
H1 += A;
H2 += B;
H3 += C;
H4 += D;
H5 += E;
//
// reset start of the buffer.
//
xOff = 0;
for (int i = 0; i < 16; i++) {
X[i] = 0;
}
}
}