KEY_PAIR: function()

in src/rsa.js [167:240]
57 lines of code
11 McCabe index (conditional complexity)

        KEY_PAIR: function(rng, e, PRIV, PUB) { /* IEEE1363 A16.11/A16.12 more or less */
            var n = PUB.n.length >> 1,
                t = new ctx.FF(n),
                p1 = new ctx.FF(n),
                q1 = new ctx.FF(n);

            for (;;) {
                PRIV.p.random(rng);

                while (PRIV.p.lastbits(2) != 3) {
                    PRIV.p.inc(1);
                }

                while (!ctx.FF.prime(PRIV.p, rng)) {
                    PRIV.p.inc(4);
                }

                p1.copy(PRIV.p);
                p1.dec(1);

                if (p1.cfactor(e)) {
                    continue;
                }

                break;
            }

            for (;;) {
                PRIV.q.random(rng);

                while (PRIV.q.lastbits(2) != 3) {
                    PRIV.q.inc(1);
                }

                while (!ctx.FF.prime(PRIV.q, rng)) {
                    PRIV.q.inc(4);
                }

                q1.copy(PRIV.q);
                q1.dec(1);

                if (q1.cfactor(e)) {
                    continue;
                }

                break;
            }

            PUB.n = ctx.FF.mul(PRIV.p, PRIV.q);
            PUB.e = e;

            t.copy(p1);
            t.shr();
            PRIV.dp.set(e);
            PRIV.dp.invmodp(t);
            if (PRIV.dp.parity() === 0) {
                PRIV.dp.add(t);
            }
            PRIV.dp.norm();

            t.copy(q1);
            t.shr();
            PRIV.dq.set(e);
            PRIV.dq.invmodp(t);
            if (PRIV.dq.parity() === 0) {
                PRIV.dq.add(t);
            }
            PRIV.dq.norm();

            PRIV.c.copy(PRIV.p);
            PRIV.c.invmodp(PRIV.q);

            return;
        },