C# (CSharp) WP.is_infinity Beispiele

Beispiel #1

/* IEEE1363 ECDSA Signature Verification. Signature C and D on F is verified using public key W */
    public static int ECPVP_DSA(sbyte[] W, sbyte[] F, sbyte[] C, sbyte[] D)
    {
        BIG r, gx, gy, f, c, d, h2;
        int res = 0;
        ECP G, WP, P;

        HASH H = new HASH();

        H.process_array(F);
        sbyte[] B = H.hash();

        gx = new BIG(ROM.CURVE_Gx);
        gy = new BIG(ROM.CURVE_Gy);

        G = new ECP(gx, gy);
        r = new BIG(ROM.CURVE_Order);

        c = BIG.fromBytes(C);
        d = BIG.fromBytes(D);
        f = BIG.fromBytes(B);

        if (c.iszilch() || BIG.comp(c, r) >= 0 || d.iszilch() || BIG.comp(d, r) >= 0)
        {
            res = INVALID;
        }

        if (res == 0)
        {
            d.invmodp(r);
            f.copy(BIG.modmul(f, d, r));
            h2 = BIG.modmul(c, d, r);

            WP = ECP.fromBytes(W);
            if (WP.is_infinity())
            {
                res = ERROR;
            }
            else
            {
                P = new ECP();
                P.copy(WP);
                P = P.mul2(h2, G, f);
                if (P.is_infinity())
                {
                    res = INVALID;
                }
                else
                {
                    d = P.X;
                    d.mod(r);
                    if (BIG.comp(d, c) != 0)
                    {
                        res = INVALID;
                    }
                }
            }
        }

        return(res);
    }