core sha1 for int array - Java Security

Description

core sha1 for int array
Demo Code


//package com.java2s;

public class Main {
    public static void main(String[] argv) throws Exception {
        int[] x = new int[] { 34, 35, 36, 37, 37, 37, 67, 68, 69 };
        int len = 2;
        System.out.println(java.util.Arrays.toString(core_sha1(x, len)));
    }/*  ww w . ja  v a  2  s . c  o m*/

    private static int[] core_sha1(int[] x, int len) {
        int size = (len >> 5);
        x = strechbinarray(x, size);
        x[len >> 5] |= 0x80 << (24 - len % 32);
        size = ((len + 64 >> 9) << 4) + 15;
        x = strechbinarray(x, size);
        x[((len + 64 >> 9) << 4) + 15] = len;

        int[] w = new int[80];
        int a = 1732584193;
        int b = -271733879;
        int c = -1732584194;
        int d = 271733878;
        int e = -1009589776;

        for (int i = 0; i < x.length; i += 16) {
            int olda = a;
            int oldb = b;
            int oldc = c;
            int oldd = d;
            int olde = e;

            for (int j = 0; j < 80; j++) {
                if (j < 16) {
                    w[j] = x[i + j];
                } else {
                    w[j] = rol(w[j - 3] ^ w[j - 8] ^ w[j - 14] ^ w[j - 16],
                            1);
                }

                int t = safe_add(safe_add(rol(a, 5), sha1_ft(j, b, c, d)),
                        safe_add(safe_add(e, w[j]), sha1_kt(j)));

                e = d;
                d = c;
                c = rol(b, 30);
                b = a;
                a = t;
            }

            a = safe_add(a, olda);
            b = safe_add(b, oldb);
            c = safe_add(c, oldc);
            d = safe_add(d, oldd);
            e = safe_add(e, olde);
        }

        int[] retval = new int[5];

        retval[0] = a;
        retval[1] = b;
        retval[2] = c;
        retval[3] = d;
        retval[4] = e;

        return retval;
    }

    private static int[] strechbinarray(int[] oldbin, int size) {
        int currlen = oldbin.length;

        if (currlen >= size + 1) {
            return oldbin;
        }

        int[] newbin = new int[size + 1];
        for (int i = 0; i < size; newbin[i] = 0, i++)
            ;

        for (int i = 0; i < currlen; i++) {
            newbin[i] = oldbin[i];
        }

        return newbin;
    }

    private static int rol(int num, int cnt) {
        return (num << cnt) | (num >>> (32 - cnt));
    }

    private static int safe_add(int x, int y) {
        int lsw = (int) (x & 0xffff) + (int) (y & 0xffff);
        int msw = (x >> 16) + (y >> 16) + (lsw >> 16);

        return (msw << 16) | (lsw & 0xffff);
    }

    private static int sha1_ft(int t, int b, int c, int d) {
        if (t < 20)
            return (b & c) | ((~b) & d);

        if (t < 40)
            return b ^ c ^ d;

        if (t < 60)
            return (b & c) | (b & d) | (c & d);

        return b ^ c ^ d;
    }

    private static int sha1_kt(int t) {
        return (t < 20) ? 1518500249 : (t < 40) ? 1859775393
                : (t < 60) ? -1894007588 : -899497514;
    }
}
core sha1 for int array - Java Security

Description

Demo Code

Related Tutorials
