Exemple #1
0
int EC_KEY_set_public_key_affine_coordinates(EC_KEY *key, BIGNUM *x,
                                             BIGNUM *y)
{
    BN_CTX *ctx = NULL;
    BIGNUM *tx, *ty;
    EC_POINT *point = NULL;
    int ok = 0;
#ifndef OPENSSL_NO_EC2M
    int tmp_nid, is_char_two = 0;
#endif

    if (key == NULL || key->group == NULL || x == NULL || y == NULL) {
        ECerr(EC_F_EC_KEY_SET_PUBLIC_KEY_AFFINE_COORDINATES,
              ERR_R_PASSED_NULL_PARAMETER);
        return 0;
    }
    ctx = BN_CTX_new();
    if (ctx == NULL)
        return 0;

    BN_CTX_start(ctx);
    point = EC_POINT_new(key->group);

    if (point == NULL)
        goto err;

    tx = BN_CTX_get(ctx);
    ty = BN_CTX_get(ctx);
    if (ty == NULL)
        goto err;

#ifndef OPENSSL_NO_EC2M
    tmp_nid = EC_METHOD_get_field_type(EC_GROUP_method_of(key->group));

    if (tmp_nid == NID_X9_62_characteristic_two_field)
        is_char_two = 1;

    if (is_char_two) {
        if (!EC_POINT_set_affine_coordinates_GF2m(key->group, point,
                                                  x, y, ctx))
            goto err;
        if (!EC_POINT_get_affine_coordinates_GF2m(key->group, point,
                                                  tx, ty, ctx))
            goto err;
    } else
#endif
    {
        if (!EC_POINT_set_affine_coordinates_GFp(key->group, point,
                                                 x, y, ctx))
            goto err;
        if (!EC_POINT_get_affine_coordinates_GFp(key->group, point,
                                                 tx, ty, ctx))
            goto err;
    }
    /*
     * Check if retrieved coordinates match originals and are less than field
     * order: if not values are out of range.
     */
    if (BN_cmp(x, tx) || BN_cmp(y, ty)
        || (BN_cmp(x, key->group->field) >= 0)
        || (BN_cmp(y, key->group->field) >= 0)) {
        ECerr(EC_F_EC_KEY_SET_PUBLIC_KEY_AFFINE_COORDINATES,
              EC_R_COORDINATES_OUT_OF_RANGE);
        goto err;
    }

    if (!EC_KEY_set_public_key(key, point))
        goto err;

    if (EC_KEY_check_key(key) == 0)
        goto err;

    ok = 1;

 err:
    BN_CTX_end(ctx);
    BN_CTX_free(ctx);
    EC_POINT_free(point);
    return ok;

}
Exemple #2
0
/* Computes scalar*point and stores the result in r.
 * point can not equal r.
 * Uses algorithm 2P of
 *     Lopez, J. and Dahab, R.  "Fast multiplication on elliptic curves over 
 *     GF(2^m) without precomputation" (CHES '99, LNCS 1717).
 */
static int ec_GF2m_montgomery_point_multiply(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar,
	const EC_POINT *point, BN_CTX *ctx)
	{
	BIGNUM *x1, *x2, *z1, *z2;
	int ret = 0, i;
	BN_ULONG mask,word;

	if (r == point)
		{
		ECerr(EC_F_EC_GF2M_MONTGOMERY_POINT_MULTIPLY, EC_R_INVALID_ARGUMENT);
		return 0;
		}
	
	/* if result should be point at infinity */
	if ((scalar == NULL) || BN_is_zero(scalar) || (point == NULL) || 
		EC_POINT_is_at_infinity(group, point))
		{
		return EC_POINT_set_to_infinity(group, r);
		}

	/* only support affine coordinates */
	if (!point->Z_is_one) return 0;

	/* Since point_multiply is static we can guarantee that ctx != NULL. */
	BN_CTX_start(ctx);
	x1 = BN_CTX_get(ctx);
	z1 = BN_CTX_get(ctx);
	if (z1 == NULL) goto err;

	x2 = &r->X;
	z2 = &r->Y;

	if (!BN_GF2m_mod_arr(x1, &point->X, group->poly)) goto err; /* x1 = x */
	if (!BN_one(z1)) goto err; /* z1 = 1 */
	if (!group->meth->field_sqr(group, z2, x1, ctx)) goto err; /* z2 = x1^2 = x^2 */
	if (!group->meth->field_sqr(group, x2, z2, ctx)) goto err;
	if (!BN_GF2m_add(x2, x2, &group->b)) goto err; /* x2 = x^4 + b */

	/* find top most bit and go one past it */
	i = scalar->top - 1;
	mask = BN_TBIT;
	word = scalar->d[i];
	while (!(word & mask)) mask >>= 1;
	mask >>= 1;
	/* if top most bit was at word break, go to next word */
	if (!mask) 
		{
		i--;
		mask = BN_TBIT;
		}

	for (; i >= 0; i--)
		{
		word = scalar->d[i];
		while (mask)
			{
			if (word & mask)
				{
				if (!gf2m_Madd(group, &point->X, x1, z1, x2, z2, ctx)) goto err;
				if (!gf2m_Mdouble(group, x2, z2, ctx)) goto err;
				}
			else
				{
				if (!gf2m_Madd(group, &point->X, x2, z2, x1, z1, ctx)) goto err;
				if (!gf2m_Mdouble(group, x1, z1, ctx)) goto err;
				}
			mask >>= 1;
			}
		mask = BN_TBIT;
		}

	/* convert out of "projective" coordinates */
	i = gf2m_Mxy(group, &point->X, &point->Y, x1, z1, x2, z2, ctx);
	if (i == 0) goto err;
	else if (i == 1) 
		{
		if (!EC_POINT_set_to_infinity(group, r)) goto err;
		}
	else
		{
		if (!BN_one(&r->Z)) goto err;
		r->Z_is_one = 1;
		}

	/* GF(2^m) field elements should always have BIGNUM::neg = 0 */
	BN_set_negative(&r->X, 0);
	BN_set_negative(&r->Y, 0);

	ret = 1;

 err:
	BN_CTX_end(ctx);
	return ret;
	}
int ec_GFp_simple_add(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a,
                      const EC_POINT *b, BN_CTX *ctx)
{
    int (*field_mul) (const EC_GROUP *, BIGNUM *, const BIGNUM *,
                      const BIGNUM *, BN_CTX *);
    int (*field_sqr) (const EC_GROUP *, BIGNUM *, const BIGNUM *, BN_CTX *);
    const BIGNUM *p;
    BN_CTX *new_ctx = NULL;
    BIGNUM *n0, *n1, *n2, *n3, *n4, *n5, *n6;
    int ret = 0;

    if (a == b)
        return EC_POINT_dbl(group, r, a, ctx);
    if (EC_POINT_is_at_infinity(group, a))
        return EC_POINT_copy(r, b);
    if (EC_POINT_is_at_infinity(group, b))
        return EC_POINT_copy(r, a);

    field_mul = group->meth->field_mul;
    field_sqr = group->meth->field_sqr;
    p = &group->field;

    if (ctx == NULL) {
        ctx = new_ctx = BN_CTX_new();
        if (ctx == NULL)
            return 0;
    }

    BN_CTX_start(ctx);
    n0 = BN_CTX_get(ctx);
    n1 = BN_CTX_get(ctx);
    n2 = BN_CTX_get(ctx);
    n3 = BN_CTX_get(ctx);
    n4 = BN_CTX_get(ctx);
    n5 = BN_CTX_get(ctx);
    n6 = BN_CTX_get(ctx);
    if (n6 == NULL)
        goto end;

    /*
     * Note that in this function we must not read components of 'a' or 'b'
     * once we have written the corresponding components of 'r'. ('r' might
     * be one of 'a' or 'b'.)
     */

    /* n1, n2 */
    if (b->Z_is_one) {
        if (!BN_copy(n1, &a->X))
            goto end;
        if (!BN_copy(n2, &a->Y))
            goto end;
        /* n1 = X_a */
        /* n2 = Y_a */
    } else {
        if (!field_sqr(group, n0, &b->Z, ctx))
            goto end;
        if (!field_mul(group, n1, &a->X, n0, ctx))
            goto end;
        /* n1 = X_a * Z_b^2 */

        if (!field_mul(group, n0, n0, &b->Z, ctx))
            goto end;
        if (!field_mul(group, n2, &a->Y, n0, ctx))
            goto end;
        /* n2 = Y_a * Z_b^3 */
    }

    /* n3, n4 */
    if (a->Z_is_one) {
        if (!BN_copy(n3, &b->X))
            goto end;
        if (!BN_copy(n4, &b->Y))
            goto end;
        /* n3 = X_b */
        /* n4 = Y_b */
    } else {
        if (!field_sqr(group, n0, &a->Z, ctx))
            goto end;
        if (!field_mul(group, n3, &b->X, n0, ctx))
            goto end;
        /* n3 = X_b * Z_a^2 */

        if (!field_mul(group, n0, n0, &a->Z, ctx))
            goto end;
        if (!field_mul(group, n4, &b->Y, n0, ctx))
            goto end;
        /* n4 = Y_b * Z_a^3 */
    }

    /* n5, n6 */
    if (!BN_mod_sub_quick(n5, n1, n3, p))
        goto end;
    if (!BN_mod_sub_quick(n6, n2, n4, p))
        goto end;
    /* n5 = n1 - n3 */
    /* n6 = n2 - n4 */

    if (BN_is_zero(n5)) {
        if (BN_is_zero(n6)) {
            /* a is the same point as b */
            BN_CTX_end(ctx);
            ret = EC_POINT_dbl(group, r, a, ctx);
            ctx = NULL;
            goto end;
        } else {
            /* a is the inverse of b */
            BN_zero(&r->Z);
            r->Z_is_one = 0;
            ret = 1;
            goto end;
        }
    }

    /* 'n7', 'n8' */
    if (!BN_mod_add_quick(n1, n1, n3, p))
        goto end;
    if (!BN_mod_add_quick(n2, n2, n4, p))
        goto end;
    /* 'n7' = n1 + n3 */
    /* 'n8' = n2 + n4 */

    /* Z_r */
    if (a->Z_is_one && b->Z_is_one) {
        if (!BN_copy(&r->Z, n5))
            goto end;
    } else {
        if (a->Z_is_one) {
            if (!BN_copy(n0, &b->Z))
                goto end;
        } else if (b->Z_is_one) {
            if (!BN_copy(n0, &a->Z))
                goto end;
        } else {
            if (!field_mul(group, n0, &a->Z, &b->Z, ctx))
                goto end;
        }
        if (!field_mul(group, &r->Z, n0, n5, ctx))
            goto end;
    }
    r->Z_is_one = 0;
    /* Z_r = Z_a * Z_b * n5 */

    /* X_r */
    if (!field_sqr(group, n0, n6, ctx))
        goto end;
    if (!field_sqr(group, n4, n5, ctx))
        goto end;
    if (!field_mul(group, n3, n1, n4, ctx))
        goto end;
    if (!BN_mod_sub_quick(&r->X, n0, n3, p))
        goto end;
    /* X_r = n6^2 - n5^2 * 'n7' */

    /* 'n9' */
    if (!BN_mod_lshift1_quick(n0, &r->X, p))
        goto end;
    if (!BN_mod_sub_quick(n0, n3, n0, p))
        goto end;
    /* n9 = n5^2 * 'n7' - 2 * X_r */

    /* Y_r */
    if (!field_mul(group, n0, n0, n6, ctx))
        goto end;
    if (!field_mul(group, n5, n4, n5, ctx))
        goto end;               /* now n5 is n5^3 */
    if (!field_mul(group, n1, n2, n5, ctx))
        goto end;
    if (!BN_mod_sub_quick(n0, n0, n1, p))
        goto end;
    if (BN_is_odd(n0))
        if (!BN_add(n0, n0, p))
            goto end;
    /* now  0 <= n0 < 2*p,  and n0 is even */
    if (!BN_rshift1(&r->Y, n0))
        goto end;
    /* Y_r = (n6 * 'n9' - 'n8' * 'n5^3') / 2 */

    ret = 1;

end:
    if (ctx)                    /* otherwise we already called BN_CTX_end */
        BN_CTX_end(ctx);
    if (new_ctx != NULL)
        BN_CTX_free(new_ctx);
    return ret;
}
// Perform ECDSA key recovery (see SEC1 4.1.6) for curves over (mod p)-fields
// recid selects which key is recovered
// if check is non-zero, additional checks are performed
int ECDSA_SIG_recover_key_GFp(EC_KEY *eckey, ECDSA_SIG *ecsig, const unsigned char *msg, int msglen, int recid, int check)
{
    if (!eckey) return 0;

    int ret = 0;
    BN_CTX *ctx = NULL;

    BIGNUM *x = NULL;
    BIGNUM *e = NULL;
    BIGNUM *order = NULL;
    BIGNUM *sor = NULL;
    BIGNUM *eor = NULL;
    BIGNUM *field = NULL;
    EC_POINT *R = NULL;
    EC_POINT *O = NULL;
    EC_POINT *Q = NULL;
    BIGNUM *rr = NULL;
    BIGNUM *zero = NULL;
    int n = 0;
    int i = recid / 2;

    const EC_GROUP *group = EC_KEY_get0_group(eckey);
    if ((ctx = BN_CTX_new()) == NULL) { ret = -1; goto err; }
    BN_CTX_start(ctx);
    order = BN_CTX_get(ctx);
    if (!EC_GROUP_get_order(group, order, ctx)) { ret = -2; goto err; }
    x = BN_CTX_get(ctx);
    if (!BN_copy(x, order)) { ret=-1; goto err; }
    if (!BN_mul_word(x, i)) { ret=-1; goto err; }
    if (!BN_add(x, x, ecsig->r)) { ret=-1; goto err; }
    field = BN_CTX_get(ctx);
    if (!EC_GROUP_get_curve_GFp(group, field, NULL, NULL, ctx)) { ret=-2; goto err; }
    if (BN_cmp(x, field) >= 0) { ret=0; goto err; }
    if ((R = EC_POINT_new(group)) == NULL) { ret = -2; goto err; }
    if (!EC_POINT_set_compressed_coordinates_GFp(group, R, x, recid % 2, ctx)) { ret=0; goto err; }
    if (check)
    {
        if ((O = EC_POINT_new(group)) == NULL) { ret = -2; goto err; }
        if (!EC_POINT_mul(group, O, NULL, R, order, ctx)) { ret=-2; goto err; }
        if (!EC_POINT_is_at_infinity(group, O)) { ret = 0; goto err; }
    }
    if ((Q = EC_POINT_new(group)) == NULL) { ret = -2; goto err; }
    n = EC_GROUP_get_degree(group);
    e = BN_CTX_get(ctx);
    if (!BN_bin2bn(msg, msglen, e)) { ret=-1; goto err; }
    if (8*msglen > n) BN_rshift(e, e, 8-(n & 7));
    zero = BN_CTX_get(ctx);
    if (!BN_zero(zero)) { ret=-1; goto err; }
    if (!BN_mod_sub(e, zero, e, order, ctx)) { ret=-1; goto err; }
    rr = BN_CTX_get(ctx);
    if (!BN_mod_inverse(rr, ecsig->r, order, ctx)) { ret=-1; goto err; }
    sor = BN_CTX_get(ctx);
    if (!BN_mod_mul(sor, ecsig->s, rr, order, ctx)) { ret=-1; goto err; }
    eor = BN_CTX_get(ctx);
    if (!BN_mod_mul(eor, e, rr, order, ctx)) { ret=-1; goto err; }
    if (!EC_POINT_mul(group, Q, eor, R, sor, ctx)) { ret=-2; goto err; }
    if (!EC_KEY_set_public_key(eckey, Q)) { ret=-2; goto err; }

    ret = 1;

err:
    if (ctx) {
        BN_CTX_end(ctx);
        BN_CTX_free(ctx);
    }
    if (R != NULL) EC_POINT_free(R);
    if (O != NULL) EC_POINT_free(O);
    if (Q != NULL) EC_POINT_free(Q);
    return ret;
}
Exemple #5
0
int BN_div_recp(BIGNUM *dv, BIGNUM *rem, const BIGNUM *m,
	BN_RECP_CTX *recp, BN_CTX *ctx)
	{
	int i,j,ret=0;
	BIGNUM *a,*b,*d,*r;

	BN_CTX_start(ctx);
	a=BN_CTX_get(ctx);
	b=BN_CTX_get(ctx);
	if (dv != NULL)
		d=dv;
	else
		d=BN_CTX_get(ctx);
	if (rem != NULL)
		r=rem;
	else
		r=BN_CTX_get(ctx);
	if (a == NULL || b == NULL || d == NULL || r == NULL) goto err;

	if (BN_ucmp(m,&(recp->N)) < 0)
		{
		BN_zero(d);
		if (!BN_copy(r,m)) return 0;
		BN_CTX_end(ctx);
		return(1);
		}

	/* We want the remainder
	 * Given input of ABCDEF / ab
	 * we need multiply ABCDEF by 3 digests of the reciprocal of ab
	 *
	 */

	/* i := max(BN_num_bits(m), 2*BN_num_bits(N)) */
	i=BN_num_bits(m);
	j=recp->num_bits<<1;
	if (j>i) i=j;

	/* Nr := round(2^i / N) */
	if (i != recp->shift)
		recp->shift=BN_reciprocal(&(recp->Nr),&(recp->N),
			i,ctx); /* BN_reciprocal returns i, or -1 for an error */
	if (recp->shift == -1) goto err;

	/* d := |round(round(m / 2^BN_num_bits(N)) * recp->Nr / 2^(i - BN_num_bits(N)))|
	 *    = |round(round(m / 2^BN_num_bits(N)) * round(2^i / N) / 2^(i - BN_num_bits(N)))|
	 *   <= |(m / 2^BN_num_bits(N)) * (2^i / N) * (2^BN_num_bits(N) / 2^i)|
	 *    = |m/N|
	 */
	if (!BN_rshift(a,m,recp->num_bits)) goto err;
	if (!BN_mul(b,a,&(recp->Nr),ctx)) goto err;
	if (!BN_rshift(d,b,i-recp->num_bits)) goto err;
	d->neg=0;

	if (!BN_mul(b,&(recp->N),d,ctx)) goto err;
	if (!BN_usub(r,m,b)) goto err;
	r->neg=0;

#if 1
	j=0;
	while (BN_ucmp(r,&(recp->N)) >= 0)
		{
		if (j++ > 2)
			{
			BNerr(BN_F_BN_DIV_RECP,BN_R_BAD_RECIPROCAL);
			goto err;
			}
		if (!BN_usub(r,r,&(recp->N))) goto err;
		if (!BN_add_word(d,1)) goto err;
		}
#endif

	r->neg=BN_is_zero(r)?0:m->neg;
	d->neg=m->neg^recp->N.neg;
	ret=1;
err:
	BN_CTX_end(ctx);
	bn_check_top(dv);
	bn_check_top(rem);
	return(ret);
	} 
Exemple #6
0
int ec_GFp_simple_point_get_affine_coordinates(const EC_GROUP *group,
                                               const EC_POINT *point,
                                               BIGNUM *x, BIGNUM *y,
                                               BN_CTX *ctx)
{
    BN_CTX *new_ctx = NULL;
    BIGNUM *Z, *Z_1, *Z_2, *Z_3;
    const BIGNUM *Z_;
    int ret = 0;

    if (EC_POINT_is_at_infinity(group, point)) {
        ECerr(EC_F_EC_GFP_SIMPLE_POINT_GET_AFFINE_COORDINATES,
              EC_R_POINT_AT_INFINITY);
        return 0;
    }

    if (ctx == NULL) {
        ctx = new_ctx = BN_CTX_new();
        if (ctx == NULL)
            return 0;
    }

    BN_CTX_start(ctx);
    Z = BN_CTX_get(ctx);
    Z_1 = BN_CTX_get(ctx);
    Z_2 = BN_CTX_get(ctx);
    Z_3 = BN_CTX_get(ctx);
    if (Z_3 == NULL)
        goto err;

    /* transform  (X, Y, Z)  into  (x, y) := (X/Z^2, Y/Z^3) */

    if (group->meth->field_decode) {
        if (!group->meth->field_decode(group, Z, &point->Z, ctx))
            goto err;
        Z_ = Z;
    } else {
        Z_ = &point->Z;
    }

    if (BN_is_one(Z_)) {
        if (group->meth->field_decode) {
            if (x != NULL) {
                if (!group->meth->field_decode(group, x, &point->X, ctx))
                    goto err;
            }
            if (y != NULL) {
                if (!group->meth->field_decode(group, y, &point->Y, ctx))
                    goto err;
            }
        } else {
            if (x != NULL) {
                if (!BN_copy(x, &point->X))
                    goto err;
            }
            if (y != NULL) {
                if (!BN_copy(y, &point->Y))
                    goto err;
            }
        }
    } else {
        if (!BN_mod_inverse(Z_1, Z_, &group->field, ctx)) {
            ECerr(EC_F_EC_GFP_SIMPLE_POINT_GET_AFFINE_COORDINATES,
                  ERR_R_BN_LIB);
            goto err;
        }

        if (group->meth->field_encode == 0) {
            /* field_sqr works on standard representation */
            if (!group->meth->field_sqr(group, Z_2, Z_1, ctx))
                goto err;
        } else {
            if (!BN_mod_sqr(Z_2, Z_1, &group->field, ctx))
                goto err;
        }

        if (x != NULL) {
            /*
             * in the Montgomery case, field_mul will cancel out Montgomery
             * factor in X:
             */
            if (!group->meth->field_mul(group, x, &point->X, Z_2, ctx))
                goto err;
        }

        if (y != NULL) {
            if (group->meth->field_encode == 0) {
                /*
                 * field_mul works on standard representation
                 */
                if (!group->meth->field_mul(group, Z_3, Z_2, Z_1, ctx))
                    goto err;
            } else {
                if (!BN_mod_mul(Z_3, Z_2, Z_1, &group->field, ctx))
                    goto err;
            }

            /*
             * in the Montgomery case, field_mul will cancel out Montgomery
             * factor in Y:
             */
            if (!group->meth->field_mul(group, y, &point->Y, Z_3, ctx))
                goto err;
        }
    }

    ret = 1;

 err:
    BN_CTX_end(ctx);
    if (new_ctx != NULL)
        BN_CTX_free(new_ctx);
    return ret;
}
Exemple #7
0
/* Computes a + b and stores the result in r.  r could be a or b, a could be b.
 * Uses algorithm A.10.2 of IEEE P1363.
 */
int 
ec_GF2m_simple_add(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a,
    const EC_POINT *b, BN_CTX *ctx)
{
	BN_CTX *new_ctx = NULL;
	BIGNUM *x0, *y0, *x1, *y1, *x2, *y2, *s, *t;
	int ret = 0;

	if (EC_POINT_is_at_infinity(group, a) > 0) {
		if (!EC_POINT_copy(r, b))
			return 0;
		return 1;
	}
	if (EC_POINT_is_at_infinity(group, b) > 0) {
		if (!EC_POINT_copy(r, a))
			return 0;
		return 1;
	}
	if (ctx == NULL) {
		ctx = new_ctx = BN_CTX_new();
		if (ctx == NULL)
			return 0;
	}
	BN_CTX_start(ctx);
	if ((x0 = BN_CTX_get(ctx)) == NULL)
		goto err;
	if ((y0 = BN_CTX_get(ctx)) == NULL)
		goto err;
	if ((x1 = BN_CTX_get(ctx)) == NULL)
		goto err;
	if ((y1 = BN_CTX_get(ctx)) == NULL)
		goto err;
	if ((x2 = BN_CTX_get(ctx)) == NULL)
		goto err;
	if ((y2 = BN_CTX_get(ctx)) == NULL)
		goto err;
	if ((s = BN_CTX_get(ctx)) == NULL)
		goto err;
	if ((t = BN_CTX_get(ctx)) == NULL)
		goto err;

	if (a->Z_is_one) {
		if (!BN_copy(x0, &a->X))
			goto err;
		if (!BN_copy(y0, &a->Y))
			goto err;
	} else {
		if (!EC_POINT_get_affine_coordinates_GF2m(group, a, x0, y0, ctx))
			goto err;
	}
	if (b->Z_is_one) {
		if (!BN_copy(x1, &b->X))
			goto err;
		if (!BN_copy(y1, &b->Y))
			goto err;
	} else {
		if (!EC_POINT_get_affine_coordinates_GF2m(group, b, x1, y1, ctx))
			goto err;
	}


	if (BN_GF2m_cmp(x0, x1)) {
		if (!BN_GF2m_add(t, x0, x1))
			goto err;
		if (!BN_GF2m_add(s, y0, y1))
			goto err;
		if (!group->meth->field_div(group, s, s, t, ctx))
			goto err;
		if (!group->meth->field_sqr(group, x2, s, ctx))
			goto err;
		if (!BN_GF2m_add(x2, x2, &group->a))
			goto err;
		if (!BN_GF2m_add(x2, x2, s))
			goto err;
		if (!BN_GF2m_add(x2, x2, t))
			goto err;
	} else {
		if (BN_GF2m_cmp(y0, y1) || BN_is_zero(x1)) {
			if (!EC_POINT_set_to_infinity(group, r))
				goto err;
			ret = 1;
			goto err;
		}
		if (!group->meth->field_div(group, s, y1, x1, ctx))
			goto err;
		if (!BN_GF2m_add(s, s, x1))
			goto err;

		if (!group->meth->field_sqr(group, x2, s, ctx))
			goto err;
		if (!BN_GF2m_add(x2, x2, s))
			goto err;
		if (!BN_GF2m_add(x2, x2, &group->a))
			goto err;
	}

	if (!BN_GF2m_add(y2, x1, x2))
		goto err;
	if (!group->meth->field_mul(group, y2, y2, s, ctx))
		goto err;
	if (!BN_GF2m_add(y2, y2, x2))
		goto err;
	if (!BN_GF2m_add(y2, y2, y1))
		goto err;

	if (!EC_POINT_set_affine_coordinates_GF2m(group, r, x2, y2, ctx))
		goto err;

	ret = 1;

err:
	BN_CTX_end(ctx);
	BN_CTX_free(new_ctx);
	return ret;
}
Exemple #8
0
size_t ec_GFp_simple_point2oct(const EC_GROUP *group, const EC_POINT *point, point_conversion_form_t form,
	unsigned char *buf, size_t len, BN_CTX *ctx)
	{
	size_t ret;
	BN_CTX *new_ctx = NULL;
	int used_ctx = 0;
	BIGNUM *x, *y;
	size_t field_len, i, skip;

	if ((form != POINT_CONVERSION_COMPRESSED)
		&& (form != POINT_CONVERSION_UNCOMPRESSED)
		&& (form != POINT_CONVERSION_HYBRID))
		{
		ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, EC_R_INVALID_FORM);
		goto err;
		}

	if (EC_POINT_is_at_infinity(group, point))
		{
		/* encodes to a single 0 octet */
		if (buf != NULL)
			{
			if (len < 1)
				{
				ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, EC_R_BUFFER_TOO_SMALL);
				return 0;
				}
			buf[0] = 0;
			}
		return 1;
		}


	/* ret := required output buffer length */
	field_len = BN_num_bytes(&group->field);
	ret = (form == POINT_CONVERSION_COMPRESSED) ? 1 + field_len : 1 + 2*field_len;

	/* if 'buf' is NULL, just return required length */
	if (buf != NULL)
		{
		if (len < ret)
			{
			ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, EC_R_BUFFER_TOO_SMALL);
			goto err;
			}

		if (ctx == NULL)
			{
			ctx = new_ctx = BN_CTX_new();
			if (ctx == NULL)
				return 0;
			}

		BN_CTX_start(ctx);
		used_ctx = 1;
		x = BN_CTX_get(ctx);
		y = BN_CTX_get(ctx);
		if (y == NULL) goto err;

		if (!EC_POINT_get_affine_coordinates_GFp(group, point, x, y, ctx)) goto err;

		if ((form == POINT_CONVERSION_COMPRESSED || form == POINT_CONVERSION_HYBRID) && BN_is_odd(y))
			buf[0] = form + 1;
		else
			buf[0] = form;
	
		i = 1;
		
		skip = field_len - BN_num_bytes(x);
		if (skip > field_len)
			{
			ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
			goto err;
			}
		while (skip > 0)
			{
			buf[i++] = 0;
			skip--;
			}
		skip = BN_bn2bin(x, buf + i);
		i += skip;
		if (i != 1 + field_len)
			{
			ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
			goto err;
			}

		if (form == POINT_CONVERSION_UNCOMPRESSED || form == POINT_CONVERSION_HYBRID)
			{
			skip = field_len - BN_num_bytes(y);
			if (skip > field_len)
				{
				ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
				goto err;
				}
			while (skip > 0)
				{
				buf[i++] = 0;
				skip--;
				}
			skip = BN_bn2bin(y, buf + i);
			i += skip;
			}

		if (i != ret)
			{
			ECerr(EC_F_EC_GFP_SIMPLE_POINT2OCT, ERR_R_INTERNAL_ERROR);
			goto err;
			}
		}
	
	if (used_ctx)
		BN_CTX_end(ctx);
	if (new_ctx != NULL)
		BN_CTX_free(new_ctx);
	return ret;

 err:
	if (used_ctx)
		BN_CTX_end(ctx);
	if (new_ctx != NULL)
		BN_CTX_free(new_ctx);
	return 0;
	}
Exemple #9
0
int ec_GFp_simple_oct2point(const EC_GROUP *group, EC_POINT *point,
	const unsigned char *buf, size_t len, BN_CTX *ctx)
	{
	point_conversion_form_t form;
	int y_bit;
	BN_CTX *new_ctx = NULL;
	BIGNUM *x, *y;
	size_t field_len, enc_len;
	int ret = 0;

	if (len == 0)
		{
		ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_BUFFER_TOO_SMALL);
		return 0;
		}
	form = buf[0];
	y_bit = form & 1;
	form = form & ~1U;
	if ((form != 0)	&& (form != POINT_CONVERSION_COMPRESSED)
		&& (form != POINT_CONVERSION_UNCOMPRESSED)
		&& (form != POINT_CONVERSION_HYBRID))
		{
		ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
		return 0;
		}
	if ((form == 0 || form == POINT_CONVERSION_UNCOMPRESSED) && y_bit)
		{
		ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
		return 0;
		}

	if (form == 0)
		{
		if (len != 1)
			{
			ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
			return 0;
			}

		return EC_POINT_set_to_infinity(group, point);
		}
	
	field_len = BN_num_bytes(&group->field);
	enc_len = (form == POINT_CONVERSION_COMPRESSED) ? 1 + field_len : 1 + 2*field_len;

	if (len != enc_len)
		{
		ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
		return 0;
		}

	if (ctx == NULL)
		{
		ctx = new_ctx = BN_CTX_new();
		if (ctx == NULL)
			return 0;
		}

	BN_CTX_start(ctx);
	x = BN_CTX_get(ctx);
	y = BN_CTX_get(ctx);
	if (y == NULL) goto err;

	if (!BN_bin2bn(buf + 1, (int)field_len, x)) goto err;
	if (BN_ucmp(x, &group->field) >= 0)
		{
		ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
		goto err;
		}

	if (form == POINT_CONVERSION_COMPRESSED)
		{
		if (!EC_POINT_set_compressed_coordinates_GFp(group, point, x, y_bit, ctx)) goto err;
		}
	else
		{
		if (!BN_bin2bn(buf + 1 + field_len, (int)field_len, y)) goto err;
		if (BN_ucmp(y, &group->field) >= 0)
			{
			ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
			goto err;
			}
		if (form == POINT_CONVERSION_HYBRID)
			{
			if (y_bit != BN_is_odd(y))
				{
				ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_INVALID_ENCODING);
				goto err;
				}
			}

		if (!EC_POINT_set_affine_coordinates_GFp(group, point, x, y, ctx)) goto err;
		}
	
	if (!EC_POINT_is_on_curve(group, point, ctx)) /* test required by X9.62 */
		{
		ECerr(EC_F_EC_GFP_SIMPLE_OCT2POINT, EC_R_POINT_IS_NOT_ON_CURVE);
		goto err;
		}

	ret = 1;
	
 err:
	BN_CTX_end(ctx);
	if (new_ctx != NULL)
		BN_CTX_free(new_ctx);
	return ret;
	}
Exemple #10
0
int ec_GFp_simple_points_make_affine(const EC_GROUP *group, size_t num, EC_POINT *points[], BN_CTX *ctx)
	{
	BN_CTX *new_ctx = NULL;
	BIGNUM *tmp0, *tmp1;
	size_t pow2 = 0;
	BIGNUM **heap = NULL;
	size_t i;
	int ret = 0;

	if (num == 0)
		return 1;

	if (ctx == NULL)
		{
		ctx = new_ctx = BN_CTX_new();
		if (ctx == NULL)
			return 0;
		}

	BN_CTX_start(ctx);
	tmp0 = BN_CTX_get(ctx);
	tmp1 = BN_CTX_get(ctx);
	if (tmp0  == NULL || tmp1 == NULL) goto err;

	/* Before converting the individual points, compute inverses of all Z values.
	 * Modular inversion is rather slow, but luckily we can do with a single
	 * explicit inversion, plus about 3 multiplications per input value.
	 */

	pow2 = 1;
	while (num > pow2)
		pow2 <<= 1;
	/* Now pow2 is the smallest power of 2 satifsying pow2 >= num.
	 * We need twice that. */
	pow2 <<= 1;

	heap = OPENSSL_malloc(pow2 * sizeof heap[0]);
	if (heap == NULL) goto err;
	
	/* The array is used as a binary tree, exactly as in heapsort:
	 *
	 *                               heap[1]
	 *                 heap[2]                     heap[3]
	 *          heap[4]       heap[5]       heap[6]       heap[7]
	 *   heap[8]heap[9] heap[10]heap[11] heap[12]heap[13] heap[14] heap[15]
	 *
	 * We put the Z's in the last line;
	 * then we set each other node to the product of its two child-nodes (where
	 * empty or 0 entries are treated as ones);
	 * then we invert heap[1];
	 * then we invert each other node by replacing it by the product of its
	 * parent (after inversion) and its sibling (before inversion).
	 */
	heap[0] = NULL;
	for (i = pow2/2 - 1; i > 0; i--)
		heap[i] = NULL;
	for (i = 0; i < num; i++)
		heap[pow2/2 + i] = &points[i]->Z;
	for (i = pow2/2 + num; i < pow2; i++)
		heap[i] = NULL;
	
	/* set each node to the product of its children */
	for (i = pow2/2 - 1; i > 0; i--)
		{
		heap[i] = BN_new();
		if (heap[i] == NULL) goto err;
		
		if (heap[2*i] != NULL)
			{
			if ((heap[2*i + 1] == NULL) || BN_is_zero(heap[2*i + 1]))
				{
				if (!BN_copy(heap[i], heap[2*i])) goto err;
				}
			else
				{
				if (BN_is_zero(heap[2*i]))
					{
					if (!BN_copy(heap[i], heap[2*i + 1])) goto err;
					}
				else
					{
					if (!group->meth->field_mul(group, heap[i],
						heap[2*i], heap[2*i + 1], ctx)) goto err;
					}
				}
			}
		}

	/* invert heap[1] */
	if (!BN_is_zero(heap[1]))
		{
		if (!BN_mod_inverse(heap[1], heap[1], &group->field, ctx))
			{
			ECerr(EC_F_EC_GFP_SIMPLE_POINTS_MAKE_AFFINE, ERR_R_BN_LIB);
			goto err;
			}
		}
	if (group->meth->field_encode != 0)
		{
		/* in the Montgomery case, we just turned  R*H  (representing H)
		 * into  1/(R*H),  but we need  R*(1/H)  (representing 1/H);
		 * i.e. we have need to multiply by the Montgomery factor twice */
		if (!group->meth->field_encode(group, heap[1], heap[1], ctx)) goto err;
		if (!group->meth->field_encode(group, heap[1], heap[1], ctx)) goto err;
		}

	/* set other heap[i]'s to their inverses */
	for (i = 2; i < pow2/2 + num; i += 2)
		{
		/* i is even */
		if ((heap[i + 1] != NULL) && !BN_is_zero(heap[i + 1]))
			{
			if (!group->meth->field_mul(group, tmp0, heap[i/2], heap[i + 1], ctx)) goto err;
			if (!group->meth->field_mul(group, tmp1, heap[i/2], heap[i], ctx)) goto err;
			if (!BN_copy(heap[i], tmp0)) goto err;
			if (!BN_copy(heap[i + 1], tmp1)) goto err;
			}
		else
			{
			if (!BN_copy(heap[i], heap[i/2])) goto err;
			}
		}

	/* we have replaced all non-zero Z's by their inverses, now fix up all the points */
	for (i = 0; i < num; i++)
		{
		EC_POINT *p = points[i];
		
		if (!BN_is_zero(&p->Z))
			{
			/* turn  (X, Y, 1/Z)  into  (X/Z^2, Y/Z^3, 1) */

			if (!group->meth->field_sqr(group, tmp1, &p->Z, ctx)) goto err;
			if (!group->meth->field_mul(group, &p->X, &p->X, tmp1, ctx)) goto err;

			if (!group->meth->field_mul(group, tmp1, tmp1, &p->Z, ctx)) goto err;
			if (!group->meth->field_mul(group, &p->Y, &p->Y, tmp1, ctx)) goto err;
		
			if (group->meth->field_set_to_one != 0)
				{
				if (!group->meth->field_set_to_one(group, &p->Z, ctx)) goto err;
				}
			else
				{
				if (!BN_one(&p->Z)) goto err;
				}
			p->Z_is_one = 1;
			}
		}

	ret = 1;
		
 err:
	BN_CTX_end(ctx);
	if (new_ctx != NULL)
		BN_CTX_free(new_ctx);
	if (heap != NULL)
		{
		/* heap[pow2/2] .. heap[pow2-1] have not been allocated locally! */
		for (i = pow2/2 - 1; i > 0; i--)
			{
			if (heap[i] != NULL)
				BN_clear_free(heap[i]);
			}
		OPENSSL_free(heap);
		}
	return ret;
	}
Exemple #11
0
int ec_GFp_simple_set_compressed_coordinates(const EC_GROUP *group, EC_POINT *point,
	const BIGNUM *x_, int y_bit, BN_CTX *ctx)
	{
	BN_CTX *new_ctx = NULL;
	BIGNUM *tmp1, *tmp2, *x, *y;
	int ret = 0;

	/* clear error queue*/
	ERR_clear_error();

	if (ctx == NULL)
		{
		ctx = new_ctx = BN_CTX_new();
		if (ctx == NULL)
			return 0;
		}

	y_bit = (y_bit != 0);

	BN_CTX_start(ctx);
	tmp1 = BN_CTX_get(ctx);
	tmp2 = BN_CTX_get(ctx);
	x = BN_CTX_get(ctx);
	y = BN_CTX_get(ctx);
	if (y == NULL) goto err;

	/* Recover y.  We have a Weierstrass equation
	 *     y^2 = x^3 + a*x + b,
	 * so  y  is one of the square roots of  x^3 + a*x + b.
	 */

	/* tmp1 := x^3 */
	if (!BN_nnmod(x, x_, &group->field,ctx)) goto err;
	if (group->meth->field_decode == 0)
		{
		/* field_{sqr,mul} work on standard representation */
		if (!group->meth->field_sqr(group, tmp2, x_, ctx)) goto err;
		if (!group->meth->field_mul(group, tmp1, tmp2, x_, ctx)) goto err;
		}
	else
		{
		if (!BN_mod_sqr(tmp2, x_, &group->field, ctx)) goto err;
		if (!BN_mod_mul(tmp1, tmp2, x_, &group->field, ctx)) goto err;
		}
	
	/* tmp1 := tmp1 + a*x */
	if (group->a_is_minus3)
		{
		if (!BN_mod_lshift1_quick(tmp2, x, &group->field)) goto err;
		if (!BN_mod_add_quick(tmp2, tmp2, x, &group->field)) goto err;
		if (!BN_mod_sub_quick(tmp1, tmp1, tmp2, &group->field)) goto err;
		}
	else
		{
		if (group->meth->field_decode)
			{
			if (!group->meth->field_decode(group, tmp2, &group->a, ctx)) goto err;
			if (!BN_mod_mul(tmp2, tmp2, x, &group->field, ctx)) goto err;
			}
		else
			{
			/* field_mul works on standard representation */
			if (!group->meth->field_mul(group, tmp2, &group->a, x, ctx)) goto err;
			}
		
		if (!BN_mod_add_quick(tmp1, tmp1, tmp2, &group->field)) goto err;
		}
	
	/* tmp1 := tmp1 + b */
	if (group->meth->field_decode)
		{
		if (!group->meth->field_decode(group, tmp2, &group->b, ctx)) goto err;
		if (!BN_mod_add_quick(tmp1, tmp1, tmp2, &group->field)) goto err;
		}
	else
		{
		if (!BN_mod_add_quick(tmp1, tmp1, &group->b, &group->field)) goto err;
		}
	
	if (!BN_mod_sqrt(y, tmp1, &group->field, ctx))
		{
		unsigned long err = ERR_peek_last_error();
		
		if (ERR_GET_LIB(err) == ERR_LIB_BN && ERR_GET_REASON(err) == BN_R_NOT_A_SQUARE)
			{
			ERR_clear_error();
			ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES, EC_R_INVALID_COMPRESSED_POINT);
			}
		else
			ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES, ERR_R_BN_LIB);
		goto err;
		}

	if (y_bit != BN_is_odd(y))
		{
		if (BN_is_zero(y))
			{
			int kron;

			kron = BN_kronecker(x, &group->field, ctx);
			if (kron == -2) goto err;

			if (kron == 1)
				ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES, EC_R_INVALID_COMPRESSION_BIT);
			else
				/* BN_mod_sqrt() should have cought this error (not a square) */
				ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES, EC_R_INVALID_COMPRESSED_POINT);
			goto err;
			}
		if (!BN_usub(y, &group->field, y)) goto err;
		}
	if (y_bit != BN_is_odd(y))
		{
		ECerr(EC_F_EC_GFP_SIMPLE_SET_COMPRESSED_COORDINATES, ERR_R_INTERNAL_ERROR);
		goto err;
		}

	if (!EC_POINT_set_affine_coordinates_GFp(group, point, x, y, ctx)) goto err;

	ret = 1;

 err:
	BN_CTX_end(ctx);
	if (new_ctx != NULL)
		BN_CTX_free(new_ctx);
	return ret;
	}
Exemple #12
0
/*
 * Fills EC_KEY structure hidden in the app_data field of DSA structure
 * with parameter information, extracted from parameter array in
 * params.c file.
 *
 * Also fils DSA->q field with copy of EC_GROUP order field to make
 * DSA_size function work
 */
int fill_GOST2001_params(EC_KEY *eckey, int nid)
{
    R3410_2001_params *params = R3410_2001_paramset;
    EC_GROUP *grp = NULL;
    BIGNUM *p = NULL, *q = NULL, *a = NULL, *b = NULL, *x = NULL, *y = NULL;
    EC_POINT *P = NULL;
    BN_CTX *ctx = BN_CTX_new();
    int ok = 0;

    if (!ctx) {
        GOSTerr(GOST_F_FILL_GOST2001_PARAMS, ERR_R_MALLOC_FAILURE);
        goto err;
    }

    BN_CTX_start(ctx);
    p = BN_CTX_get(ctx);
    a = BN_CTX_get(ctx);
    b = BN_CTX_get(ctx);
    x = BN_CTX_get(ctx);
    y = BN_CTX_get(ctx);
    q = BN_CTX_get(ctx);
    if (!p || !a || !b || !x || !y || !q) {
        GOSTerr(GOST_F_FILL_GOST2001_PARAMS, ERR_R_MALLOC_FAILURE);
        goto err;
    }
    while (params->nid != NID_undef && params->nid != nid)
        params++;
    if (params->nid == NID_undef) {
        GOSTerr(GOST_F_FILL_GOST2001_PARAMS,
                GOST_R_UNSUPPORTED_PARAMETER_SET);
        goto err;
    }
    if (!BN_hex2bn(&p, params->p)
        || !BN_hex2bn(&a, params->a)
        || !BN_hex2bn(&b, params->b)) {
        GOSTerr(GOST_F_FILL_GOST2001_PARAMS,
                ERR_R_INTERNAL_ERROR);
        goto err;
    }

    grp = EC_GROUP_new_curve_GFp(p, a, b, ctx);
    if (!grp)  {
        GOSTerr(GOST_F_FILL_GOST2001_PARAMS, ERR_R_MALLOC_FAILURE);
        goto err;
    }

    P = EC_POINT_new(grp);
    if (!P)  {
        GOSTerr(GOST_F_FILL_GOST2001_PARAMS, ERR_R_MALLOC_FAILURE);
        goto err;
    }

    if (!BN_hex2bn(&x, params->x)
        || !BN_hex2bn(&y, params->y)
        || !EC_POINT_set_affine_coordinates_GFp(grp, P, x, y, ctx)
        || !BN_hex2bn(&q, params->q))  {
        GOSTerr(GOST_F_FILL_GOST2001_PARAMS, ERR_R_INTERNAL_ERROR);
        goto err;
    }
#ifdef DEBUG_KEYS
    fprintf(stderr, "Set params index %d oid %s\nq=",
            (params - R3410_2001_paramset), OBJ_nid2sn(params->nid));
    BN_print_fp(stderr, q);
    fprintf(stderr, "\n");
#endif

    if (!EC_GROUP_set_generator(grp, P, q, NULL)) {
        GOSTerr(GOST_F_FILL_GOST2001_PARAMS, ERR_R_INTERNAL_ERROR);
        goto err;
    }
    EC_GROUP_set_curve_name(grp, params->nid);
    if (!EC_KEY_set_group(eckey, grp)) {
        GOSTerr(GOST_F_FILL_GOST2001_PARAMS, ERR_R_INTERNAL_ERROR);
        goto err;
    }
    ok = 1;
 err:
    EC_POINT_free(P);
    EC_GROUP_free(grp);
    if (ctx)
        BN_CTX_end(ctx);
    BN_CTX_free(ctx);
    return ok;
}
Exemple #13
0
/*
 * Verifies gost 2001 signature
 *
 */
int gost2001_do_verify(const unsigned char *dgst, int dgst_len,
                       DSA_SIG *sig, EC_KEY *ec)
{
    BN_CTX *ctx = BN_CTX_new();
    const EC_GROUP *group = EC_KEY_get0_group(ec);
    BIGNUM *order;
    BIGNUM *md = NULL, *e = NULL, *R = NULL, *v = NULL, *z1 = NULL, *z2 =
        NULL;
    BIGNUM *X = NULL, *tmp = NULL;
    EC_POINT *C = NULL;
    const EC_POINT *pub_key = NULL;
    int ok = 0;

    if (!ctx || !group) {
        GOSTerr(GOST_F_GOST2001_DO_VERIFY, ERR_R_INTERNAL_ERROR);
        goto err;
    }

    BN_CTX_start(ctx);
    order = BN_CTX_get(ctx);
    e = BN_CTX_get(ctx);
    z1 = BN_CTX_get(ctx);
    z2 = BN_CTX_get(ctx);
    tmp = BN_CTX_get(ctx);
    X = BN_CTX_get(ctx);
    R = BN_CTX_get(ctx);
    v = BN_CTX_get(ctx);
    if (!order || !e || !z1 || !z2 || !tmp || !X || !R || !v) {
        GOSTerr(GOST_F_GOST2001_DO_VERIFY, ERR_R_MALLOC_FAILURE);
        goto err;
    }

    pub_key = EC_KEY_get0_public_key(ec);
    if (!pub_key || !EC_GROUP_get_order(group, order, ctx)) {
        GOSTerr(GOST_F_GOST2001_DO_VERIFY, ERR_R_INTERNAL_ERROR);
        goto err;
    }

    if (BN_is_zero(sig->s) || BN_is_zero(sig->r) ||
        (BN_cmp(sig->s, order) >= 1) || (BN_cmp(sig->r, order) >= 1)) {
        GOSTerr(GOST_F_GOST2001_DO_VERIFY,
                GOST_R_SIGNATURE_PARTS_GREATER_THAN_Q);
        goto err;

    }
    md = hashsum2bn(dgst);

    if (!md || !BN_mod(e, md, order, ctx)) {
        GOSTerr(GOST_F_GOST2001_DO_VERIFY, ERR_R_INTERNAL_ERROR);
        goto err;
    }
#ifdef DEBUG_SIGN
    fprintf(stderr, "digest as bignum: ");
    BN_print_fp(stderr, md);
    fprintf(stderr, "\ndigest mod q: ");
    BN_print_fp(stderr, e);
#endif
    if (BN_is_zero(e) && !BN_one(e)) {
        GOSTerr(GOST_F_GOST2001_DO_VERIFY, ERR_R_INTERNAL_ERROR);
        goto err;
    }
    v = BN_mod_inverse(v, e, order, ctx);
    if (!v
        || !BN_mod_mul(z1, sig->s, v, order, ctx)
        || !BN_sub(tmp, order, sig->r)
        || !BN_mod_mul(z2, tmp, v, order, ctx)) {
        GOSTerr(GOST_F_GOST2001_DO_VERIFY, ERR_R_INTERNAL_ERROR);
        goto err;
    }
#ifdef DEBUG_SIGN
    fprintf(stderr, "\nInverted digest value: ");
    BN_print_fp(stderr, v);
    fprintf(stderr, "\nz1: ");
    BN_print_fp(stderr, z1);
    fprintf(stderr, "\nz2: ");
    BN_print_fp(stderr, z2);
#endif
    C = EC_POINT_new(group);
    if (!C) {
        GOSTerr(GOST_F_GOST2001_DO_VERIFY, ERR_R_MALLOC_FAILURE);
        goto err;
    }
    if (!EC_POINT_mul(group, C, z1, pub_key, z2, ctx)) {
        GOSTerr(GOST_F_GOST2001_DO_VERIFY, ERR_R_EC_LIB);
        goto err;
    }
    if (!EC_POINT_get_affine_coordinates_GFp(group, C, X, NULL, ctx)) {
        GOSTerr(GOST_F_GOST2001_DO_VERIFY, ERR_R_EC_LIB);
        goto err;
    }
    if (!BN_mod(R, X, order, ctx)) {
        GOSTerr(GOST_F_GOST2001_DO_VERIFY, ERR_R_INTERNAL_ERROR);
        goto err;
    }
#ifdef DEBUG_SIGN
    fprintf(stderr, "\nX=");
    BN_print_fp(stderr, X);
    fprintf(stderr, "\nX mod q=");
    BN_print_fp(stderr, R);
    fprintf(stderr, "\n");
#endif
    if (BN_cmp(R, sig->r) != 0) {
        GOSTerr(GOST_F_GOST2001_DO_VERIFY, GOST_R_SIGNATURE_MISMATCH);
    } else {
        ok = 1;
    }
 err:
    EC_POINT_free(C);
    if (ctx)
        BN_CTX_end(ctx);
    BN_CTX_free(ctx);
    BN_free(md);
    return ok;
}
Exemple #14
0
/*
 * Computes gost2001 signature as DSA_SIG structure
 *
 *
 */
DSA_SIG *gost2001_do_sign(const unsigned char *dgst, int dlen, EC_KEY *eckey)
{
    DSA_SIG *newsig = NULL, *ret = NULL;
    BIGNUM *md = hashsum2bn(dgst);
    BIGNUM *order = NULL;
    const EC_GROUP *group;
    const BIGNUM *priv_key;
    BIGNUM *r = NULL, *s = NULL, *X = NULL, *tmp = NULL, *tmp2 = NULL, *k =
        NULL, *e = NULL;
    EC_POINT *C = NULL;
    BN_CTX *ctx = BN_CTX_new();
    if (!ctx || !md) {
        GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_MALLOC_FAILURE);
        goto err;
    }
    BN_CTX_start(ctx);
    OPENSSL_assert(dlen == 32);
    newsig = DSA_SIG_new();
    if (!newsig) {
        GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_MALLOC_FAILURE);
        goto err;
    }
    group = EC_KEY_get0_group(eckey);
    if (!group) {
        GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_INTERNAL_ERROR);
        goto err;
    }
    order = BN_CTX_get(ctx);
    if (!order || !EC_GROUP_get_order(group, order, ctx)) {
        GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_INTERNAL_ERROR);
        goto err;
    }
    priv_key = EC_KEY_get0_private_key(eckey);
    if (!priv_key) {
        GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_INTERNAL_ERROR);
        goto err;
    }
    e = BN_CTX_get(ctx);
    if (!e || !BN_mod(e, md, order, ctx)) {
        GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_INTERNAL_ERROR);
        goto err;
    }
#ifdef DEBUG_SIGN
    fprintf(stderr, "digest as bignum=");
    BN_print_fp(stderr, md);
    fprintf(stderr, "\ndigest mod q=");
    BN_print_fp(stderr, e);
    fprintf(stderr, "\n");
#endif
    if (BN_is_zero(e)) {
        BN_one(e);
    }
    k = BN_CTX_get(ctx);
    C = EC_POINT_new(group);
    if (!k || !C) {
        GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_MALLOC_FAILURE);
        goto err;
    }
    do {
        do {
            if (!BN_rand_range(k, order)) {
                GOSTerr(GOST_F_GOST2001_DO_SIGN,
                        GOST_R_RANDOM_NUMBER_GENERATOR_FAILED);
                goto err;
            }
            if (!EC_POINT_mul(group, C, k, NULL, NULL, ctx)) {
                GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_EC_LIB);
                goto err;
            }
            if (!X)
                X = BN_CTX_get(ctx);
            if (!r)
                r = BN_CTX_get(ctx);
            if (!X || !r) {
                GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_MALLOC_FAILURE);
                goto err;
            }
            if (!EC_POINT_get_affine_coordinates_GFp(group, C, X, NULL, ctx)) {
                GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_EC_LIB);
                goto err;
            }

            if (!BN_nnmod(r, X, order, ctx)) {
                GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_INTERNAL_ERROR);
                goto err;
            }
        }
        while (BN_is_zero(r));
        /* s =  (r*priv_key+k*e) mod order */
        if (!tmp)
            tmp = BN_CTX_get(ctx);
        if (!tmp2)
            tmp2 = BN_CTX_get(ctx);
        if (!s)
            s = BN_CTX_get(ctx);
        if (!tmp || !tmp2 || !s) {
            GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_MALLOC_FAILURE);
            goto err;
        }

        if (!BN_mod_mul(tmp, priv_key, r, order, ctx)
            || !BN_mod_mul(tmp2, k, e, order, ctx)
            || !BN_mod_add(s, tmp, tmp2, order, ctx)) {
            GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_INTERNAL_ERROR);
            goto err;
        }
    }
    while (BN_is_zero(s));

    newsig->s = BN_dup(s);
    newsig->r = BN_dup(r);
    if (!newsig->s || !newsig->r) {
        GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_MALLOC_FAILURE);
        goto err;
    }

    ret = newsig;
 err:
    if (ctx)
        BN_CTX_end(ctx);
    BN_CTX_free(ctx);
    EC_POINT_free(C);
    BN_free(md);
    if (!ret)
        DSA_SIG_free(newsig);
    return ret;
}
Exemple #15
0
int ec_GFp_simple_points_make_affine(const EC_GROUP *group, size_t num,
                                     EC_POINT *points[], BN_CTX *ctx)
{
    BN_CTX *new_ctx = NULL;
    BIGNUM *tmp, *tmp_Z;
    BIGNUM **prod_Z = NULL;
    size_t i;
    int ret = 0;

    if (num == 0)
        return 1;

    if (ctx == NULL) {
        ctx = new_ctx = BN_CTX_new();
        if (ctx == NULL)
            return 0;
    }

    BN_CTX_start(ctx);
    tmp = BN_CTX_get(ctx);
    tmp_Z = BN_CTX_get(ctx);
    if (tmp == NULL || tmp_Z == NULL)
        goto err;

    prod_Z = OPENSSL_malloc(num * sizeof(prod_Z[0]));
    if (prod_Z == NULL)
        goto err;
    for (i = 0; i < num; i++) {
        prod_Z[i] = BN_new();
        if (prod_Z[i] == NULL)
            goto err;
    }

    /*
     * Set each prod_Z[i] to the product of points[0]->Z .. points[i]->Z,
     * skipping any zero-valued inputs (pretend that they're 1).
     */

    if (!BN_is_zero(&points[0]->Z)) {
        if (!BN_copy(prod_Z[0], &points[0]->Z))
            goto err;
    } else {
        if (group->meth->field_set_to_one != 0) {
            if (!group->meth->field_set_to_one(group, prod_Z[0], ctx))
                goto err;
        } else {
            if (!BN_one(prod_Z[0]))
                goto err;
        }
    }

    for (i = 1; i < num; i++) {
        if (!BN_is_zero(&points[i]->Z)) {
            if (!group->meth->field_mul(group, prod_Z[i], prod_Z[i - 1],
                                        &points[i]->Z, ctx))
                goto err;
        } else {
            if (!BN_copy(prod_Z[i], prod_Z[i - 1]))
                goto err;
        }
    }

    /*
     * Now use a single explicit inversion to replace every non-zero
     * points[i]->Z by its inverse.
     */

    if (!BN_mod_inverse(tmp, prod_Z[num - 1], &group->field, ctx)) {
        ECerr(EC_F_EC_GFP_SIMPLE_POINTS_MAKE_AFFINE, ERR_R_BN_LIB);
        goto err;
    }
    if (group->meth->field_encode != 0) {
        /*
         * In the Montgomery case, we just turned R*H (representing H) into
         * 1/(R*H), but we need R*(1/H) (representing 1/H); i.e. we need to
         * multiply by the Montgomery factor twice.
         */
        if (!group->meth->field_encode(group, tmp, tmp, ctx))
            goto err;
        if (!group->meth->field_encode(group, tmp, tmp, ctx))
            goto err;
    }

    for (i = num - 1; i > 0; --i) {
        /*
         * Loop invariant: tmp is the product of the inverses of points[0]->Z
         * .. points[i]->Z (zero-valued inputs skipped).
         */
        if (!BN_is_zero(&points[i]->Z)) {
            /*
             * Set tmp_Z to the inverse of points[i]->Z (as product of Z
             * inverses 0 .. i, Z values 0 .. i - 1).
             */
            if (!group->
                meth->field_mul(group, tmp_Z, prod_Z[i - 1], tmp, ctx))
                goto err;
            /*
             * Update tmp to satisfy the loop invariant for i - 1.
             */
            if (!group->meth->field_mul(group, tmp, tmp, &points[i]->Z, ctx))
                goto err;
            /* Replace points[i]->Z by its inverse. */
            if (!BN_copy(&points[i]->Z, tmp_Z))
                goto err;
        }
    }

    if (!BN_is_zero(&points[0]->Z)) {
        /* Replace points[0]->Z by its inverse. */
        if (!BN_copy(&points[0]->Z, tmp))
            goto err;
    }

    /* Finally, fix up the X and Y coordinates for all points. */

    for (i = 0; i < num; i++) {
        EC_POINT *p = points[i];

        if (!BN_is_zero(&p->Z)) {
            /* turn  (X, Y, 1/Z)  into  (X/Z^2, Y/Z^3, 1) */

            if (!group->meth->field_sqr(group, tmp, &p->Z, ctx))
                goto err;
            if (!group->meth->field_mul(group, &p->X, &p->X, tmp, ctx))
                goto err;

            if (!group->meth->field_mul(group, tmp, tmp, &p->Z, ctx))
                goto err;
            if (!group->meth->field_mul(group, &p->Y, &p->Y, tmp, ctx))
                goto err;

            if (group->meth->field_set_to_one != 0) {
                if (!group->meth->field_set_to_one(group, &p->Z, ctx))
                    goto err;
            } else {
                if (!BN_one(&p->Z))
                    goto err;
            }
            p->Z_is_one = 1;
        }
    }

    ret = 1;

 err:
    BN_CTX_end(ctx);
    if (new_ctx != NULL)
        BN_CTX_free(new_ctx);
    if (prod_Z != NULL) {
        for (i = 0; i < num; i++) {
            if (prod_Z[i] == NULL)
                break;
            BN_clear_free(prod_Z[i]);
        }
        OPENSSL_free(prod_Z);
    }
    return ret;
}
Exemple #16
0
static int ecdsa_do_verify(const unsigned char *dgst, int dgst_len,
		const ECDSA_SIG *sig, EC_KEY *eckey)
{
	int ret = -1, i;
	BN_CTX   *ctx;
	BIGNUM   *order, *u1, *u2, *m, *X;
	EC_POINT *point = NULL;
	const EC_GROUP *group;
	const EC_POINT *pub_key;

	/* check input values */
	if (eckey == NULL || (group = EC_KEY_get0_group(eckey)) == NULL ||
	    (pub_key = EC_KEY_get0_public_key(eckey)) == NULL || sig == NULL)
	{
		ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ECDSA_R_MISSING_PARAMETERS);
		return -1;
	}

	ctx = BN_CTX_new();
	if (!ctx)
	{
		ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_MALLOC_FAILURE);
		return -1;
	}
	BN_CTX_start(ctx);
	order = BN_CTX_get(ctx);	
	u1    = BN_CTX_get(ctx);
	u2    = BN_CTX_get(ctx);
	m     = BN_CTX_get(ctx);
	X     = BN_CTX_get(ctx);
	if (!X)
	{
		ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
		goto err;
	}
	
	if (!EC_GROUP_get_order(group, order, ctx))
	{
		ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_EC_LIB);
		goto err;
	}

	if (BN_is_zero(sig->r)          || BN_is_negative(sig->r) || 
	    BN_ucmp(sig->r, order) >= 0 || BN_is_zero(sig->s)  ||
	    BN_is_negative(sig->s)      || BN_ucmp(sig->s, order) >= 0)
	{
		ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ECDSA_R_BAD_SIGNATURE);
		ret = 0;	/* signature is invalid */
		goto err;
	}
	/* calculate tmp1 = inv(S) mod order */
	if (!BN_mod_inverse(u2, sig->s, order, ctx))
	{
		ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
		goto err;
	}
	/* digest -> m */
	i = BN_num_bits(order);
	/* Need to truncate digest if it is too long: first truncate whole
	 * bytes.
	 */
	if (8 * dgst_len > i)
		dgst_len = (i + 7)/8;
	if (!BN_bin2bn(dgst, dgst_len, m))
	{
		ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
		goto err;
	}
	/* If still too long truncate remaining bits with a shift */
	if ((8 * dgst_len > i) && !BN_rshift(m, m, 8 - (i & 0x7)))
	{
		ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
		goto err;
	}
	/* u1 = m * tmp mod order */
	if (!BN_mod_mul(u1, m, u2, order, ctx))
	{
		ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
		goto err;
	}
	/* u2 = r * w mod q */
	if (!BN_mod_mul(u2, sig->r, u2, order, ctx))
	{
		ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
		goto err;
	}

	if ((point = EC_POINT_new(group)) == NULL)
	{
		ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_MALLOC_FAILURE);
		goto err;
	}
	if (!EC_POINT_mul(group, point, u1, pub_key, u2, ctx))
	{
		ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_EC_LIB);
		goto err;
	}
	if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) == NID_X9_62_prime_field)
	{
		if (!EC_POINT_get_affine_coordinates_GFp(group,
			point, X, NULL, ctx))
		{
			ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_EC_LIB);
			goto err;
		}
	}
#ifndef OPENSSL_NO_EC2M
	else /* NID_X9_62_characteristic_two_field */
	{
		if (!EC_POINT_get_affine_coordinates_GF2m(group,
			point, X, NULL, ctx))
		{
			ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_EC_LIB);
			goto err;
		}
	}
#endif	
	if (!BN_nnmod(u1, X, order, ctx))
	{
		ECDSAerr(ECDSA_F_ECDSA_DO_VERIFY, ERR_R_BN_LIB);
		goto err;
	}
	/*  if the signature is correct u1 is equal to sig->r */
	ret = (BN_ucmp(u1, sig->r) == 0);
err:
	BN_CTX_end(ctx);
	BN_CTX_free(ctx);
	if (point)
		EC_POINT_free(point);
	return ret;
}
Exemple #17
0
int ec_GFp_simple_group_check_discriminant(const EC_GROUP *group, BN_CTX *ctx)
{
    int ret = 0;
    BIGNUM *a, *b, *order, *tmp_1, *tmp_2;
    const BIGNUM *p = &group->field;
    BN_CTX *new_ctx = NULL;

    if (ctx == NULL) {
        ctx = new_ctx = BN_CTX_new();
        if (ctx == NULL) {
            ECerr(EC_F_EC_GFP_SIMPLE_GROUP_CHECK_DISCRIMINANT,
                  ERR_R_MALLOC_FAILURE);
            goto err;
        }
    }
    BN_CTX_start(ctx);
    a = BN_CTX_get(ctx);
    b = BN_CTX_get(ctx);
    tmp_1 = BN_CTX_get(ctx);
    tmp_2 = BN_CTX_get(ctx);
    order = BN_CTX_get(ctx);
    if (order == NULL)
        goto err;

    if (group->meth->field_decode) {
        if (!group->meth->field_decode(group, a, &group->a, ctx))
            goto err;
        if (!group->meth->field_decode(group, b, &group->b, ctx))
            goto err;
    } else {
        if (!BN_copy(a, &group->a))
            goto err;
        if (!BN_copy(b, &group->b))
            goto err;
    }

    /*-
     * check the discriminant:
     * y^2 = x^3 + a*x + b is an elliptic curve <=> 4*a^3 + 27*b^2 != 0 (mod p)
     * 0 =< a, b < p
     */
    if (BN_is_zero(a)) {
        if (BN_is_zero(b))
            goto err;
    } else if (!BN_is_zero(b)) {
        if (!BN_mod_sqr(tmp_1, a, p, ctx))
            goto err;
        if (!BN_mod_mul(tmp_2, tmp_1, a, p, ctx))
            goto err;
        if (!BN_lshift(tmp_1, tmp_2, 2))
            goto err;
        /* tmp_1 = 4*a^3 */

        if (!BN_mod_sqr(tmp_2, b, p, ctx))
            goto err;
        if (!BN_mul_word(tmp_2, 27))
            goto err;
        /* tmp_2 = 27*b^2 */

        if (!BN_mod_add(a, tmp_1, tmp_2, p, ctx))
            goto err;
        if (BN_is_zero(a))
            goto err;
    }
    ret = 1;

 err:
    if (ctx != NULL)
        BN_CTX_end(ctx);
    if (new_ctx != NULL)
        BN_CTX_free(new_ctx);
    return ret;
}
static int RSA_eay_public_encrypt(int flen, const unsigned char *from,
	     unsigned char *to, RSA *rsa, int padding)
	{
	BIGNUM *f,*ret;
	int i,j,k,num=0,r= -1;
	unsigned char *buf=NULL;
	BN_CTX *ctx=NULL;

	if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS)
		{
		RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_MODULUS_TOO_LARGE);
		return -1;
		}

	if (BN_ucmp(rsa->n, rsa->e) <= 0)
		{
		RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE);
		return -1;
		}

	/* for large moduli, enforce exponent limit */
	if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS)
		{
		if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS)
			{
			RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE);
			return -1;
			}
		}
	
	if ((ctx=BN_CTX_new()) == NULL) goto err;
	BN_CTX_start(ctx);
	f = BN_CTX_get(ctx);
	ret = BN_CTX_get(ctx);
	num=BN_num_bytes(rsa->n);
	buf = (unsigned char*)OPENSSL_malloc(num);
	if (!f || !ret || !buf)
		{
		RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,ERR_R_MALLOC_FAILURE);
		goto err;
		}

	switch (padding)
		{
	case RSA_PKCS1_PADDING:
		i=RSA_padding_add_PKCS1_type_2(buf,num,from,flen);
		break;
#ifndef OPENSSL_NO_SHA
	case RSA_PKCS1_OAEP_PADDING:
	        i=RSA_padding_add_PKCS1_OAEP(buf,num,from,flen,NULL,0);
		break;
#endif
	case RSA_SSLV23_PADDING:
		i=RSA_padding_add_SSLv23(buf,num,from,flen);
		break;
	case RSA_NO_PADDING:
		i=RSA_padding_add_none(buf,num,from,flen);
		break;
	default:
		RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
		goto err;
		}
	if (i <= 0) goto err;

	if (BN_bin2bn(buf,num,f) == NULL) goto err;
	
	if (BN_ucmp(f, rsa->n) >= 0)
		{
		/* usually the padding functions would catch this */
		RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
		goto err;
		}

	if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
		if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
			goto err;

	if (!rsa->meth->bn_mod_exp(ret,f,rsa->e,rsa->n,ctx,
		rsa->_method_mod_n)) goto err;

	/* put in leading 0 bytes if the number is less than the
	 * length of the modulus */
	j=BN_num_bytes(ret);
	i=BN_bn2bin(ret,&(to[num-j]));
	for (k=0; k<(num-i); k++)
		to[k]=0;

	r=num;
err:
	if (ctx != NULL)
		{
		BN_CTX_end(ctx);
		BN_CTX_free(ctx);
		}
	if (buf != NULL) 
		{
		OPENSSL_cleanse(buf,num);
		OPENSSL_free(buf);
		}
	return(r);
	}
Exemple #19
0
int ec_GFp_simple_is_on_curve(const EC_GROUP *group, const EC_POINT *point,
                              BN_CTX *ctx)
{
    int (*field_mul) (const EC_GROUP *, BIGNUM *, const BIGNUM *,
                      const BIGNUM *, BN_CTX *);
    int (*field_sqr) (const EC_GROUP *, BIGNUM *, const BIGNUM *, BN_CTX *);
    const BIGNUM *p;
    BN_CTX *new_ctx = NULL;
    BIGNUM *rh, *tmp, *Z4, *Z6;
    int ret = -1;

    if (EC_POINT_is_at_infinity(group, point))
        return 1;

    field_mul = group->meth->field_mul;
    field_sqr = group->meth->field_sqr;
    p = &group->field;

    if (ctx == NULL) {
        ctx = new_ctx = BN_CTX_new();
        if (ctx == NULL)
            return -1;
    }

    BN_CTX_start(ctx);
    rh = BN_CTX_get(ctx);
    tmp = BN_CTX_get(ctx);
    Z4 = BN_CTX_get(ctx);
    Z6 = BN_CTX_get(ctx);
    if (Z6 == NULL)
        goto err;

    /*-
     * We have a curve defined by a Weierstrass equation
     *      y^2 = x^3 + a*x + b.
     * The point to consider is given in Jacobian projective coordinates
     * where  (X, Y, Z)  represents  (x, y) = (X/Z^2, Y/Z^3).
     * Substituting this and multiplying by  Z^6  transforms the above equation into
     *      Y^2 = X^3 + a*X*Z^4 + b*Z^6.
     * To test this, we add up the right-hand side in 'rh'.
     */

    /* rh := X^2 */
    if (!field_sqr(group, rh, &point->X, ctx))
        goto err;

    if (!point->Z_is_one) {
        if (!field_sqr(group, tmp, &point->Z, ctx))
            goto err;
        if (!field_sqr(group, Z4, tmp, ctx))
            goto err;
        if (!field_mul(group, Z6, Z4, tmp, ctx))
            goto err;

        /* rh := (rh + a*Z^4)*X */
        if (group->a_is_minus3) {
            if (!BN_mod_lshift1_quick(tmp, Z4, p))
                goto err;
            if (!BN_mod_add_quick(tmp, tmp, Z4, p))
                goto err;
            if (!BN_mod_sub_quick(rh, rh, tmp, p))
                goto err;
            if (!field_mul(group, rh, rh, &point->X, ctx))
                goto err;
        } else {
            if (!field_mul(group, tmp, Z4, &group->a, ctx))
                goto err;
            if (!BN_mod_add_quick(rh, rh, tmp, p))
                goto err;
            if (!field_mul(group, rh, rh, &point->X, ctx))
                goto err;
        }

        /* rh := rh + b*Z^6 */
        if (!field_mul(group, tmp, &group->b, Z6, ctx))
            goto err;
        if (!BN_mod_add_quick(rh, rh, tmp, p))
            goto err;
    } else {
        /* point->Z_is_one */

        /* rh := (rh + a)*X */
        if (!BN_mod_add_quick(rh, rh, &group->a, p))
            goto err;
        if (!field_mul(group, rh, rh, &point->X, ctx))
            goto err;
        /* rh := rh + b */
        if (!BN_mod_add_quick(rh, rh, &group->b, p))
            goto err;
    }

    /* 'lh' := Y^2 */
    if (!field_sqr(group, tmp, &point->Y, ctx))
        goto err;

    ret = (0 == BN_ucmp(tmp, rh));

 err:
    BN_CTX_end(ctx);
    if (new_ctx != NULL)
        BN_CTX_free(new_ctx);
    return ret;
}
/* signing */
static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
	     unsigned char *to, RSA *rsa, int padding)
	{
	BIGNUM *f, *ret, *br, *res;
	int i,j,k,num=0,r= -1;
	unsigned char *buf=NULL;
	BN_CTX *ctx=NULL;
	int local_blinding = 0;
	BN_BLINDING *blinding = NULL;

	if ((ctx=BN_CTX_new()) == NULL) goto err;
	BN_CTX_start(ctx);
	f   = BN_CTX_get(ctx);
	br  = BN_CTX_get(ctx);
	ret = BN_CTX_get(ctx);
	num = BN_num_bytes(rsa->n);
	buf = (unsigned char*)OPENSSL_malloc(num);
	if(!f || !ret || !buf)
		{
		RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,ERR_R_MALLOC_FAILURE);
		goto err;
		}

	switch (padding)
		{
	case RSA_PKCS1_PADDING:
		i=RSA_padding_add_PKCS1_type_1(buf,num,from,flen);
		break;
	case RSA_X931_PADDING:
		i=RSA_padding_add_X931(buf,num,from,flen);
		break;
	case RSA_NO_PADDING:
		i=RSA_padding_add_none(buf,num,from,flen);
		break;
	case RSA_SSLV23_PADDING:
	default:
		RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
		goto err;
		}
	if (i <= 0) goto err;

	if (BN_bin2bn(buf,num,f) == NULL) goto err;
	
	if (BN_ucmp(f, rsa->n) >= 0)
		{	
		/* usually the padding functions would catch this */
		RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
		goto err;
		}

	if (!(rsa->flags & RSA_FLAG_NO_BLINDING))
		{
		blinding = rsa_get_blinding(rsa, &local_blinding, ctx);
		if (blinding == NULL)
			{
			RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_INTERNAL_ERROR);
			goto err;
			}
		}
	
	if (blinding != NULL)
		if (!rsa_blinding_convert(blinding, local_blinding, f, br, ctx))
			goto err;

	if ( (rsa->flags & RSA_FLAG_EXT_PKEY) ||
		((rsa->p != NULL) &&
		(rsa->q != NULL) &&
		(rsa->dmp1 != NULL) &&
		(rsa->dmq1 != NULL) &&
		(rsa->iqmp != NULL)) )
		{ 
		if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx)) goto err;
		}
	else
		{
		BIGNUM local_d;
		BIGNUM *d = NULL;
		
		if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
			{
			BN_init(&local_d);
			d = &local_d;
			BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
			}
		else
			d= rsa->d;

		if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
			if(!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
				goto err;

		if (!rsa->meth->bn_mod_exp(ret,f,d,rsa->n,ctx,
				rsa->_method_mod_n)) goto err;
		}

	if (blinding)
		if (!rsa_blinding_invert(blinding, local_blinding, ret, br, ctx))
			goto err;

	if (padding == RSA_X931_PADDING)
		{
		BN_sub(f, rsa->n, ret);
		if (BN_cmp(ret, f))
			res = f;
		else
			res = ret;
		}
	else
		res = ret;

	/* put in leading 0 bytes if the number is less than the
	 * length of the modulus */
	j=BN_num_bytes(res);
	i=BN_bn2bin(res,&(to[num-j]));
	for (k=0; k<(num-i); k++)
		to[k]=0;

	r=num;
err:
	if (ctx != NULL)
		{
		BN_CTX_end(ctx);
		BN_CTX_free(ctx);
		}
	if (buf != NULL)
		{
		OPENSSL_cleanse(buf,num);
		OPENSSL_free(buf);
		}
	return(r);
	}
Exemple #21
0
/* Actually there is no reason to insist that 'generator' be a generator.
 * It's just as OK (and in some sense better) to use a generator of the
 * order-q subgroup.
 */
static int dh_builtin_genparams(DH *ret, int prime_len, int generator, BN_GENCB *cb)
	{
	BIGNUM *t1,*t2;
	int g,ok= -1;
	BN_CTX *ctx=NULL;

	ctx=BN_CTX_new();
	if (ctx == NULL) goto err;
	BN_CTX_start(ctx);
	t1 = BN_CTX_get(ctx);
	t2 = BN_CTX_get(ctx);
	if (t1 == NULL || t2 == NULL) goto err;

	/* Make sure 'ret' has the necessary elements */
	if(!ret->p && ((ret->p = BN_new()) == NULL)) goto err;
	if(!ret->g && ((ret->g = BN_new()) == NULL)) goto err;
	
	if (generator <= 1)
		{
		DHerr(DH_F_DH_BUILTIN_GENPARAMS, DH_R_BAD_GENERATOR);
		goto err;
		}
	if (generator == DH_GENERATOR_2)
		{
		if (!BN_set_word(t1,24)) goto err;
		if (!BN_set_word(t2,11)) goto err;
		g=2;
		}
#if 0 /* does not work for safe primes */
	else if (generator == DH_GENERATOR_3)
		{
		if (!BN_set_word(t1,12)) goto err;
		if (!BN_set_word(t2,5)) goto err;
		g=3;
		}
#endif
	else if (generator == DH_GENERATOR_5)
		{
		if (!BN_set_word(t1,10)) goto err;
		if (!BN_set_word(t2,3)) goto err;
		/* BN_set_word(t3,7); just have to miss
		 * out on these ones :-( */
		g=5;
		}
	else
		{
		/* in the general case, don't worry if 'generator' is a
		 * generator or not: since we are using safe primes,
		 * it will generate either an order-q or an order-2q group,
		 * which both is OK */
		if (!BN_set_word(t1,2)) goto err;
		if (!BN_set_word(t2,1)) goto err;
		g=generator;
		}
	
	if(!BN_generate_prime_ex(ret->p,prime_len,1,t1,t2,cb)) goto err;
	if(!BN_GENCB_call(cb, 3, 0)) goto err;
	if (!BN_set_word(ret->g,g)) goto err;
	ok=1;
err:
	if (ok == -1)
		{
		DHerr(DH_F_DH_BUILTIN_GENPARAMS,ERR_R_BN_LIB);
		ok=0;
		}

	if (ctx != NULL)
		{
		BN_CTX_end(ctx);
		BN_CTX_free(ctx);
		}
	return ok;
	}
static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
	     unsigned char *to, RSA *rsa, int padding)
	{
	BIGNUM *f, *ret, *br;
	int j,num=0,r= -1;
	unsigned char *p;
	unsigned char *buf=NULL;
	BN_CTX *ctx=NULL;
	int local_blinding = 0;
	BN_BLINDING *blinding = NULL;

	if((ctx = BN_CTX_new()) == NULL) goto err;
	BN_CTX_start(ctx);
	f   = BN_CTX_get(ctx);
	br  = BN_CTX_get(ctx);
	ret = BN_CTX_get(ctx);
	num = BN_num_bytes(rsa->n);
	buf = (unsigned char*)OPENSSL_malloc(num);
	if(!f || !ret || !buf)
		{
		RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,ERR_R_MALLOC_FAILURE);
		goto err;
		}

	/* This check was for equality but PGP does evil things
	 * and chops off the top '0' bytes */
	if (flen > num)
		{
		RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN);
		goto err;
		}

	/* make data into a big number */
	if (BN_bin2bn(from,(int)flen,f) == NULL) goto err;

	if (BN_ucmp(f, rsa->n) >= 0)
		{
		RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
		goto err;
		}

	if (!(rsa->flags & RSA_FLAG_NO_BLINDING))
		{
		blinding = rsa_get_blinding(rsa, &local_blinding, ctx);
		if (blinding == NULL)
			{
			RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, ERR_R_INTERNAL_ERROR);
			goto err;
			}
		}
	
	if (blinding != NULL)
		if (!rsa_blinding_convert(blinding, local_blinding, f, br, ctx))
			goto err;

	/* do the decrypt */
	if ( (rsa->flags & RSA_FLAG_EXT_PKEY) ||
		((rsa->p != NULL) &&
		(rsa->q != NULL) &&
		(rsa->dmp1 != NULL) &&
		(rsa->dmq1 != NULL) &&
		(rsa->iqmp != NULL)) )
		{
		if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx)) goto err;
		}
	else
		{
		BIGNUM local_d;
		BIGNUM *d = NULL;
		
		if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
			{
			d = &local_d;
			BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
			}
		else
			d = rsa->d;

		if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
			if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
				goto err;
		if (!rsa->meth->bn_mod_exp(ret,f,d,rsa->n,ctx,
				rsa->_method_mod_n))
		  goto err;
		}

	if (blinding)
		if (!rsa_blinding_invert(blinding, local_blinding, ret, br, ctx))
			goto err;

	p=buf;
	j=BN_bn2bin(ret,p); /* j is only used with no-padding mode */

	switch (padding)
		{
	case RSA_PKCS1_PADDING:
		r=RSA_padding_check_PKCS1_type_2(to,num,buf,j,num);
		break;
#ifndef OPENSSL_NO_SHA
        case RSA_PKCS1_OAEP_PADDING:
	        r=RSA_padding_check_PKCS1_OAEP(to,num,buf,j,num,NULL,0);
                break;
#endif
 	case RSA_SSLV23_PADDING:
		r=RSA_padding_check_SSLv23(to,num,buf,j,num);
		break;
	case RSA_NO_PADDING:
		r=RSA_padding_check_none(to,num,buf,j,num);
		break;
	default:
		RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
		goto err;
		}
	if (r < 0)
		RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT,RSA_R_PADDING_CHECK_FAILED);

err:
	if (ctx != NULL)
		{
		BN_CTX_end(ctx);
		BN_CTX_free(ctx);
		}
	if (buf != NULL)
		{
		OPENSSL_cleanse(buf,num);
		OPENSSL_free(buf);
		}
	return(r);
	}
Exemple #23
0
/* BN_div_no_branch is a special version of BN_div. It does not contain
 * branches that may leak sensitive information.
 */
static int BN_div_no_branch(BIGNUM *dv, BIGNUM *rm, const BIGNUM *num, 
	const BIGNUM *divisor, BN_CTX *ctx)
	{
	int norm_shift,i,loop;
	BIGNUM *tmp,wnum,*snum,*sdiv,*res;
	BN_ULONG *resp,*wnump;
	BN_ULONG d0,d1;
	int num_n,div_n;

	bn_check_top(dv);
	bn_check_top(rm);
	/* bn_check_top(num); */ /* 'num' has been checked in BN_div() */
	bn_check_top(divisor);

	if (BN_is_zero(divisor))
		{
		BNerr(BN_F_BN_DIV_NO_BRANCH,BN_R_DIV_BY_ZERO);
		return(0);
		}

	BN_CTX_start(ctx);
	tmp=BN_CTX_get(ctx);
	snum=BN_CTX_get(ctx);
	sdiv=BN_CTX_get(ctx);
	if (dv == NULL)
		res=BN_CTX_get(ctx);
	else	res=dv;
	if (sdiv == NULL || res == NULL) goto err;

	/* First we normalise the numbers */
	norm_shift=BN_BITS2-((BN_num_bits(divisor))%BN_BITS2);
	if (!(BN_lshift(sdiv,divisor,norm_shift))) goto err;
	sdiv->neg=0;
	norm_shift+=BN_BITS2;
	if (!(BN_lshift(snum,num,norm_shift))) goto err;
	snum->neg=0;

	/* Since we don't know whether snum is larger than sdiv,
	 * we pad snum with enough zeroes without changing its
	 * value. 
	 */
	if (snum->top <= sdiv->top+1) 
		{
		if (bn_wexpand(snum, sdiv->top + 2) == NULL) goto err;
		for (i = snum->top; i < sdiv->top + 2; i++) snum->d[i] = 0;
		snum->top = sdiv->top + 2;
		}
	else
		{
		if (bn_wexpand(snum, snum->top + 1) == NULL) goto err;
		snum->d[snum->top] = 0;
		snum->top ++;
		}

	div_n=sdiv->top;
	num_n=snum->top;
	loop=num_n-div_n;
	/* Lets setup a 'window' into snum
	 * This is the part that corresponds to the current
	 * 'area' being divided */
	wnum.neg   = 0;
	wnum.d     = &(snum->d[loop]);
	wnum.top   = div_n;
	/* only needed when BN_ucmp messes up the values between top and max */
	wnum.dmax  = snum->dmax - loop; /* so we don't step out of bounds */

	/* Get the top 2 words of sdiv */
	/* div_n=sdiv->top; */
	d0=sdiv->d[div_n-1];
	d1=(div_n == 1)?0:sdiv->d[div_n-2];

	/* pointer to the 'top' of snum */
	wnump= &(snum->d[num_n-1]);

	/* Setup to 'res' */
	res->neg= (num->neg^divisor->neg);
	if (!bn_wexpand(res,(loop+1))) goto err;
	res->top=loop-1;
	resp= &(res->d[loop-1]);

	/* space for temp */
	if (!bn_wexpand(tmp,(div_n+1))) goto err;

	/* if res->top == 0 then clear the neg value otherwise decrease
	 * the resp pointer */
	if (res->top == 0)
		res->neg = 0;
	else
		resp--;

	for (i=0; i<loop-1; i++, wnump--, resp--)
		{
		BN_ULONG q,l0;
		/* the first part of the loop uses the top two words of
		 * snum and sdiv to calculate a BN_ULONG q such that
		 * | wnum - sdiv * q | < sdiv */
#if defined(BN_DIV3W) && !defined(OPENSSL_NO_ASM)
		BN_ULONG bn_div_3_words(BN_ULONG*,BN_ULONG,BN_ULONG);
		q=bn_div_3_words(wnump,d1,d0);
#else
		BN_ULONG n0,n1,rem=0;

		n0=wnump[0];
		n1=wnump[-1];
		if (n0 == d0)
			q=BN_MASK2;
		else 			/* n0 < d0 */
			{
#ifdef BN_LLONG
			BN_ULLONG t2;

#if defined(BN_LLONG) && defined(BN_DIV2W) && !defined(bn_div_words)
			q=(BN_ULONG)(((((BN_ULLONG)n0)<<BN_BITS2)|n1)/d0);
#else
			q=bn_div_words(n0,n1,d0);
#ifdef BN_DEBUG_LEVITTE
			fprintf(stderr,"DEBUG: bn_div_words(0x%08X,0x%08X,0x%08\
X) -> 0x%08X\n",
				n0, n1, d0, q);
#endif
#endif

#ifndef REMAINDER_IS_ALREADY_CALCULATED
			/*
			 * rem doesn't have to be BN_ULLONG. The least we
			 * know it's less that d0, isn't it?
			 */
			rem=(n1-q*d0)&BN_MASK2;
#endif
			t2=(BN_ULLONG)d1*q;

			for (;;)
				{
				if (t2 <= ((((BN_ULLONG)rem)<<BN_BITS2)|wnump[-2]))
					break;
				q--;
				rem += d0;
				if (rem < d0) break; /* don't let rem overflow */
				t2 -= d1;
				}
#else /* !BN_LLONG */
			BN_ULONG t2l,t2h;
#if !defined(BN_UMULT_LOHI) && !defined(BN_UMULT_HIGH)
			BN_ULONG ql,qh;
#endif

			q=bn_div_words(n0,n1,d0);
#ifdef BN_DEBUG_LEVITTE
			fprintf(stderr,"DEBUG: bn_div_words(0x%08X,0x%08X,0x%08\
X) -> 0x%08X\n",
				n0, n1, d0, q);
#endif
#ifndef REMAINDER_IS_ALREADY_CALCULATED
			rem=(n1-q*d0)&BN_MASK2;
#endif

#if defined(BN_UMULT_LOHI)
			BN_UMULT_LOHI(t2l,t2h,d1,q);
#elif defined(BN_UMULT_HIGH)
			t2l = d1 * q;
			t2h = BN_UMULT_HIGH(d1,q);
#else
			t2l=LBITS(d1); t2h=HBITS(d1);
			ql =LBITS(q);  qh =HBITS(q);
			mul64(t2l,t2h,ql,qh); /* t2=(BN_ULLONG)d1*q; */
#endif

			for (;;)
				{
				if ((t2h < rem) ||
					((t2h == rem) && (t2l <= wnump[-2])))
					break;
				q--;
				rem += d0;
				if (rem < d0) break; /* don't let rem overflow */
				if (t2l < d1) t2h--; t2l -= d1;
				}
#endif /* !BN_LLONG */
			}
#endif /* !BN_DIV3W */

		l0=bn_mul_words(tmp->d,sdiv->d,div_n,q);
		tmp->d[div_n]=l0;
		wnum.d--;
		/* ingore top values of the bignums just sub the two 
		 * BN_ULONG arrays with bn_sub_words */
		if (bn_sub_words(wnum.d, wnum.d, tmp->d, div_n+1))
			{
			/* Note: As we have considered only the leading
			 * two BN_ULONGs in the calculation of q, sdiv * q
			 * might be greater than wnum (but then (q-1) * sdiv
			 * is less or equal than wnum)
			 */
			q--;
			if (bn_add_words(wnum.d, wnum.d, sdiv->d, div_n))
				/* we can't have an overflow here (assuming
				 * that q != 0, but if q == 0 then tmp is
				 * zero anyway) */
				(*wnump)++;
			}
		/* store part of the result */
		*resp = q;
		}
	bn_correct_top(snum);
	if (rm != NULL)
		{
		/* Keep a copy of the neg flag in num because if rm==num
		 * BN_rshift() will overwrite it.
		 */
		int neg = num->neg;
		BN_rshift(rm,snum,norm_shift);
		if (!BN_is_zero(rm))
			rm->neg = neg;
		bn_check_top(rm);
		}
	bn_correct_top(res);
	BN_CTX_end(ctx);
	return(1);
err:
	bn_check_top(rm);
	BN_CTX_end(ctx);
	return(0);
	}
/* signature verification */
static int RSA_eay_public_decrypt(int flen, const unsigned char *from,
	     unsigned char *to, RSA *rsa, int padding)
	{
	BIGNUM *f,*ret;
	int i,num=0,r= -1;
	unsigned char *p;
	unsigned char *buf=NULL;
	BN_CTX *ctx=NULL;

	if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS)
		{
		RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_MODULUS_TOO_LARGE);
		return -1;
		}

	if (BN_ucmp(rsa->n, rsa->e) <= 0)
		{
		RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE);
		return -1;
		}

	/* for large moduli, enforce exponent limit */
	if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS)
		{
		if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS)
			{
			RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, RSA_R_BAD_E_VALUE);
			return -1;
			}
		}
	
	if((ctx = BN_CTX_new()) == NULL) goto err;
	BN_CTX_start(ctx);
	f = BN_CTX_get(ctx);
	ret = BN_CTX_get(ctx);
	num=BN_num_bytes(rsa->n);
	buf = (unsigned char*)OPENSSL_malloc(num);
	if(!f || !ret || !buf)
		{
		RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,ERR_R_MALLOC_FAILURE);
		goto err;
		}

	/* This check was for equality but PGP does evil things
	 * and chops off the top '0' bytes */
	if (flen > num)
		{
		RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_GREATER_THAN_MOD_LEN);
		goto err;
		}

	if (BN_bin2bn(from,flen,f) == NULL) goto err;

	if (BN_ucmp(f, rsa->n) >= 0)
		{
		RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
		goto err;
		}

	if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
		if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
			goto err;

	if (!rsa->meth->bn_mod_exp(ret,f,rsa->e,rsa->n,ctx,
		rsa->_method_mod_n)) goto err;

	if ((padding == RSA_X931_PADDING) && ((ret->d[0] & 0xf) != 12))
		if (!BN_sub(ret, rsa->n, ret)) goto err;

	p=buf;
	i=BN_bn2bin(ret,p);

	switch (padding)
		{
	case RSA_PKCS1_PADDING:
		r=RSA_padding_check_PKCS1_type_1(to,num,buf,i,num);
		break;
	case RSA_X931_PADDING:
		r=RSA_padding_check_X931(to,num,buf,i,num);
		break;
	case RSA_NO_PADDING:
		r=RSA_padding_check_none(to,num,buf,i,num);
		break;
	default:
		RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_UNKNOWN_PADDING_TYPE);
		goto err;
		}
	if (r < 0)
		RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT,RSA_R_PADDING_CHECK_FAILED);

err:
	if (ctx != NULL)
		{
		BN_CTX_end(ctx);
		BN_CTX_free(ctx);
		}
	if (buf != NULL)
		{
		OPENSSL_cleanse(buf,num);
		OPENSSL_free(buf);
		}
	return(r);
	}
Exemple #25
0
/* This implementation is based on the following primitives in the IEEE 1363 standard:
 *  - ECKAS-DH1
 *  - ECSVDP-DH
 * Finally an optional KDF is applied.
 */
static int ecdh_compute_key(void *out, size_t outlen, const EC_POINT *pub_key,
	EC_KEY *ecdh,
	void *(*KDF)(const void *in, size_t inlen, void *out, size_t *outlen))
	{
	BN_CTX *ctx;
	EC_POINT *tmp=NULL;
	BIGNUM *x=NULL, *y=NULL;
	const BIGNUM *priv_key;
	const EC_GROUP* group;
	int ret= -1;
	size_t buflen, len;
	unsigned char *buf=NULL;

	if (outlen > INT_MAX)
		{
		ECDHerr(ECDH_F_ECDH_COMPUTE_KEY,ERR_R_MALLOC_FAILURE); /* sort of, anyway */
		return -1;
		}

	if ((ctx = BN_CTX_new()) == NULL) goto err;
	BN_CTX_start(ctx);
	x = BN_CTX_get(ctx);
	y = BN_CTX_get(ctx);
	
	priv_key = EC_KEY_get0_private_key(ecdh);
	if (priv_key == NULL)
		{
		ECDHerr(ECDH_F_ECDH_COMPUTE_KEY,ECDH_R_NO_PRIVATE_VALUE);
		goto err;
		}

	group = EC_KEY_get0_group(ecdh);
	if ((tmp=EC_POINT_new(group)) == NULL)
		{
		ECDHerr(ECDH_F_ECDH_COMPUTE_KEY,ERR_R_MALLOC_FAILURE);
		goto err;
		}

	if (!EC_POINT_mul(group, tmp, NULL, pub_key, priv_key, ctx)) 
		{
		ECDHerr(ECDH_F_ECDH_COMPUTE_KEY,ECDH_R_POINT_ARITHMETIC_FAILURE);
		goto err;
		}
		
	if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) == NID_X9_62_prime_field) 
		{
		if (!EC_POINT_get_affine_coordinates_GFp(group, tmp, x, y, ctx)) 
			{
			ECDHerr(ECDH_F_ECDH_COMPUTE_KEY,ECDH_R_POINT_ARITHMETIC_FAILURE);
			goto err;
			}
		}
#ifndef OPENSSL_NO_EC2M
	else
		{
		if (!EC_POINT_get_affine_coordinates_GF2m(group, tmp, x, y, ctx)) 
			{
			ECDHerr(ECDH_F_ECDH_COMPUTE_KEY,ECDH_R_POINT_ARITHMETIC_FAILURE);
			goto err;
			}
		}
#endif

	buflen = (EC_GROUP_get_degree(group) + 7)/8;
	len = BN_num_bytes(x);
	if (len > buflen)
		{
		ECDHerr(ECDH_F_ECDH_COMPUTE_KEY,ERR_R_INTERNAL_ERROR);
		goto err;
		}
	if ((buf = OPENSSL_malloc(buflen)) == NULL)
		{
		ECDHerr(ECDH_F_ECDH_COMPUTE_KEY,ERR_R_MALLOC_FAILURE);
		goto err;
		}
	
	memset(buf, 0, buflen - len);
	if (len != (size_t)BN_bn2bin(x, buf + buflen - len))
		{
		ECDHerr(ECDH_F_ECDH_COMPUTE_KEY,ERR_R_BN_LIB);
		goto err;
		}

	if (KDF != 0)
		{
		if (KDF(buf, buflen, out, &outlen) == NULL)
			{
			ECDHerr(ECDH_F_ECDH_COMPUTE_KEY,ECDH_R_KDF_FAILED);
			goto err;
			}
		ret = outlen;
		}
	else
		{
		/* no KDF, just copy as much as we can */
		if (outlen > buflen)
			outlen = buflen;
		memcpy(out, buf, outlen);
		ret = outlen;
		}
	
err:
	if (tmp) EC_POINT_free(tmp);
	if (ctx) BN_CTX_end(ctx);
	if (ctx) BN_CTX_free(ctx);
	if (buf) OPENSSL_free(buf);
	return(ret);
	}
static int RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)
	{
	BIGNUM *r1,*m1,*vrfy;
	BIGNUM local_dmp1,local_dmq1,local_c,local_r1;
	BIGNUM *dmp1,*dmq1,*c,*pr1;
	int ret=0;

	BN_CTX_start(ctx);
	r1 = BN_CTX_get(ctx);
	m1 = BN_CTX_get(ctx);
	vrfy = BN_CTX_get(ctx);

	{
		BIGNUM local_p, local_q;
		BIGNUM *p = NULL, *q = NULL;

		/* Make sure BN_mod_inverse in Montgomery intialization uses the
		 * BN_FLG_CONSTTIME flag (unless RSA_FLAG_NO_CONSTTIME is set)
		 */
		if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
			{
			BN_init(&local_p);
			p = &local_p;
			BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME);

			BN_init(&local_q);
			q = &local_q;
			BN_with_flags(q, rsa->q, BN_FLG_CONSTTIME);
			}
		else
			{
			p = rsa->p;
			q = rsa->q;
			}

		if (rsa->flags & RSA_FLAG_CACHE_PRIVATE)
			{
			if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_p, CRYPTO_LOCK_RSA, p, ctx))
				goto err;
			if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_q, CRYPTO_LOCK_RSA, q, ctx))
				goto err;
			}
	}

	if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
		if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, CRYPTO_LOCK_RSA, rsa->n, ctx))
			goto err;

	/* compute I mod q */
	if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
		{
		c = &local_c;
		BN_with_flags(c, I, BN_FLG_CONSTTIME);
		if (!BN_mod(r1,c,rsa->q,ctx)) goto err;
		}
	else
		{
		if (!BN_mod(r1,I,rsa->q,ctx)) goto err;
		}

	/* compute r1^dmq1 mod q */
	if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
		{
		dmq1 = &local_dmq1;
		BN_with_flags(dmq1, rsa->dmq1, BN_FLG_CONSTTIME);
		}
	else
		dmq1 = rsa->dmq1;
	if (!rsa->meth->bn_mod_exp(m1,r1,dmq1,rsa->q,ctx,
		rsa->_method_mod_q)) goto err;

	/* compute I mod p */
	if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
		{
		c = &local_c;
		BN_with_flags(c, I, BN_FLG_CONSTTIME);
		if (!BN_mod(r1,c,rsa->p,ctx)) goto err;
		}
	else
		{
		if (!BN_mod(r1,I,rsa->p,ctx)) goto err;
		}

	/* compute r1^dmp1 mod p */
	if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
		{
		dmp1 = &local_dmp1;
		BN_with_flags(dmp1, rsa->dmp1, BN_FLG_CONSTTIME);
		}
	else
		dmp1 = rsa->dmp1;
	if (!rsa->meth->bn_mod_exp(r0,r1,dmp1,rsa->p,ctx,
		rsa->_method_mod_p)) goto err;

	if (!BN_sub(r0,r0,m1)) goto err;
	/* This will help stop the size of r0 increasing, which does
	 * affect the multiply if it optimised for a power of 2 size */
	if (BN_is_negative(r0))
		if (!BN_add(r0,r0,rsa->p)) goto err;

	if (!BN_mul(r1,r0,rsa->iqmp,ctx)) goto err;

	/* Turn BN_FLG_CONSTTIME flag on before division operation */
	if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
		{
		pr1 = &local_r1;
		BN_with_flags(pr1, r1, BN_FLG_CONSTTIME);
		}
	else
		pr1 = r1;
	if (!BN_mod(r0,pr1,rsa->p,ctx)) goto err;

	/* If p < q it is occasionally possible for the correction of
         * adding 'p' if r0 is negative above to leave the result still
	 * negative. This can break the private key operations: the following
	 * second correction should *always* correct this rare occurrence.
	 * This will *never* happen with OpenSSL generated keys because
         * they ensure p > q [steve]
         */
	if (BN_is_negative(r0))
		if (!BN_add(r0,r0,rsa->p)) goto err;
	if (!BN_mul(r1,r0,rsa->q,ctx)) goto err;
	if (!BN_add(r0,r1,m1)) goto err;

	if (rsa->e && rsa->n)
		{
		if (!rsa->meth->bn_mod_exp(vrfy,r0,rsa->e,rsa->n,ctx,rsa->_method_mod_n)) goto err;
		/* If 'I' was greater than (or equal to) rsa->n, the operation
		 * will be equivalent to using 'I mod n'. However, the result of
		 * the verify will *always* be less than 'n' so we don't check
		 * for absolute equality, just congruency. */
		if (!BN_sub(vrfy, vrfy, I)) goto err;
		if (!BN_mod(vrfy, vrfy, rsa->n, ctx)) goto err;
		if (BN_is_negative(vrfy))
			if (!BN_add(vrfy, vrfy, rsa->n)) goto err;
		if (!BN_is_zero(vrfy))
			{
			/* 'I' and 'vrfy' aren't congruent mod n. Don't leak
			 * miscalculated CRT output, just do a raw (slower)
			 * mod_exp and return that instead. */

			BIGNUM local_d;
			BIGNUM *d = NULL;
		
			if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
				{
				d = &local_d;
				BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
				}
			else
				d = rsa->d;
			if (!rsa->meth->bn_mod_exp(r0,I,d,rsa->n,ctx,
						   rsa->_method_mod_n)) goto err;
			}
		}
	ret=1;
err:
	BN_CTX_end(ctx);
	return(ret);
	}
Exemple #27
0
int
BN_X931_derive_prime_ex(BIGNUM *p, BIGNUM *p1, BIGNUM *p2, const BIGNUM *Xp,
    const BIGNUM *Xp1, const BIGNUM *Xp2, const BIGNUM *e, BN_CTX *ctx,
    BN_GENCB *cb)
{
	int ret = 0;

	BIGNUM *t, *p1p2, *pm1;

	/* Only even e supported */
	if (!BN_is_odd(e))
		return 0;

	BN_CTX_start(ctx);
	if (!p1)
		p1 = BN_CTX_get(ctx);

	if (!p2)
		p2 = BN_CTX_get(ctx);

	t = BN_CTX_get(ctx);

	p1p2 = BN_CTX_get(ctx);

	pm1 = BN_CTX_get(ctx);

	if (!bn_x931_derive_pi(p1, Xp1, ctx, cb))
		goto err;

	if (!bn_x931_derive_pi(p2, Xp2, ctx, cb))
		goto err;

	if (!BN_mul(p1p2, p1, p2, ctx))
		goto err;

	/* First set p to value of Rp */

	if (!BN_mod_inverse(p, p2, p1, ctx))
		goto err;

	if (!BN_mul(p, p, p2, ctx))
		goto err;

	if (!BN_mod_inverse(t, p1, p2, ctx))
		goto err;

	if (!BN_mul(t, t, p1, ctx))
		goto err;

	if (!BN_sub(p, p, t))
		goto err;

	if (p->neg && !BN_add(p, p, p1p2))
		goto err;

	/* p now equals Rp */

	if (!BN_mod_sub(p, p, Xp, p1p2, ctx))
		goto err;

	if (!BN_add(p, p, Xp))
		goto err;

	/* p now equals Yp0 */

	for (;;) {
		int i = 1;
		BN_GENCB_call(cb, 0, i++);
		if (!BN_copy(pm1, p))
			goto err;
		if (!BN_sub_word(pm1, 1))
			goto err;
		if (!BN_gcd(t, pm1, e, ctx))
			goto err;
		if (BN_is_one(t)
		/* X9.31 specifies 8 MR and 1 Lucas test or any prime test
		 * offering similar or better guarantees 50 MR is considerably
		 * better.
		 */
		    && BN_is_prime_fasttest_ex(p, 50, ctx, 1, cb))
			break;
		if (!BN_add(p, p, p1p2))
			goto err;
	}

	BN_GENCB_call(cb, 3, 0);

	ret = 1;

err:

	BN_CTX_end(ctx);

	return ret;
}
Exemple #28
0
int ec_GFp_simple_cmp(const EC_GROUP *group, const EC_POINT *a,
                      const EC_POINT *b, BN_CTX *ctx)
{
    /*-
     * return values:
     *  -1   error
     *   0   equal (in affine coordinates)
     *   1   not equal
     */

    int (*field_mul) (const EC_GROUP *, BIGNUM *, const BIGNUM *,
                      const BIGNUM *, BN_CTX *);
    int (*field_sqr) (const EC_GROUP *, BIGNUM *, const BIGNUM *, BN_CTX *);
    BN_CTX *new_ctx = NULL;
    BIGNUM *tmp1, *tmp2, *Za23, *Zb23;
    const BIGNUM *tmp1_, *tmp2_;
    int ret = -1;

    if (EC_POINT_is_at_infinity(group, a)) {
        return EC_POINT_is_at_infinity(group, b) ? 0 : 1;
    }

    if (EC_POINT_is_at_infinity(group, b))
        return 1;

    if (a->Z_is_one && b->Z_is_one) {
        return ((BN_cmp(&a->X, &b->X) == 0)
                && BN_cmp(&a->Y, &b->Y) == 0) ? 0 : 1;
    }

    field_mul = group->meth->field_mul;
    field_sqr = group->meth->field_sqr;

    if (ctx == NULL) {
        ctx = new_ctx = BN_CTX_new();
        if (ctx == NULL)
            return -1;
    }

    BN_CTX_start(ctx);
    tmp1 = BN_CTX_get(ctx);
    tmp2 = BN_CTX_get(ctx);
    Za23 = BN_CTX_get(ctx);
    Zb23 = BN_CTX_get(ctx);
    if (Zb23 == NULL)
        goto end;

    /*-
     * We have to decide whether
     *     (X_a/Z_a^2, Y_a/Z_a^3) = (X_b/Z_b^2, Y_b/Z_b^3),
     * or equivalently, whether
     *     (X_a*Z_b^2, Y_a*Z_b^3) = (X_b*Z_a^2, Y_b*Z_a^3).
     */

    if (!b->Z_is_one) {
        if (!field_sqr(group, Zb23, &b->Z, ctx))
            goto end;
        if (!field_mul(group, tmp1, &a->X, Zb23, ctx))
            goto end;
        tmp1_ = tmp1;
    } else
        tmp1_ = &a->X;
    if (!a->Z_is_one) {
        if (!field_sqr(group, Za23, &a->Z, ctx))
            goto end;
        if (!field_mul(group, tmp2, &b->X, Za23, ctx))
            goto end;
        tmp2_ = tmp2;
    } else
        tmp2_ = &b->X;

    /* compare  X_a*Z_b^2  with  X_b*Z_a^2 */
    if (BN_cmp(tmp1_, tmp2_) != 0) {
        ret = 1;                /* points differ */
        goto end;
    }

    if (!b->Z_is_one) {
        if (!field_mul(group, Zb23, Zb23, &b->Z, ctx))
            goto end;
        if (!field_mul(group, tmp1, &a->Y, Zb23, ctx))
            goto end;
        /* tmp1_ = tmp1 */
    } else
        tmp1_ = &a->Y;
    if (!a->Z_is_one) {
        if (!field_mul(group, Za23, Za23, &a->Z, ctx))
            goto end;
        if (!field_mul(group, tmp2, &b->Y, Za23, ctx))
            goto end;
        /* tmp2_ = tmp2 */
    } else
        tmp2_ = &b->Y;

    /* compare  Y_a*Z_b^3  with  Y_b*Z_a^3 */
    if (BN_cmp(tmp1_, tmp2_) != 0) {
        ret = 1;                /* points differ */
        goto end;
    }

    /* points are equal */
    ret = 0;

 end:
    BN_CTX_end(ctx);
    if (new_ctx != NULL)
        BN_CTX_free(new_ctx);
    return ret;
}
int ec_GFp_simple_dbl(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a,
                      BN_CTX *ctx)
{
    int (*field_mul) (const EC_GROUP *, BIGNUM *, const BIGNUM *,
                      const BIGNUM *, BN_CTX *);
    int (*field_sqr) (const EC_GROUP *, BIGNUM *, const BIGNUM *, BN_CTX *);
    const BIGNUM *p;
    BN_CTX *new_ctx = NULL;
    BIGNUM *n0, *n1, *n2, *n3;
    int ret = 0;

    if (EC_POINT_is_at_infinity(group, a)) {
        BN_zero(&r->Z);
        r->Z_is_one = 0;
        return 1;
    }

    field_mul = group->meth->field_mul;
    field_sqr = group->meth->field_sqr;
    p = &group->field;

    if (ctx == NULL) {
        ctx = new_ctx = BN_CTX_new();
        if (ctx == NULL)
            return 0;
    }

    BN_CTX_start(ctx);
    n0 = BN_CTX_get(ctx);
    n1 = BN_CTX_get(ctx);
    n2 = BN_CTX_get(ctx);
    n3 = BN_CTX_get(ctx);
    if (n3 == NULL)
        goto err;

    /*
     * Note that in this function we must not read components of 'a' once we
     * have written the corresponding components of 'r'. ('r' might the same
     * as 'a'.)
     */

    /* n1 */
    if (a->Z_is_one) {
        if (!field_sqr(group, n0, &a->X, ctx))
            goto err;
        if (!BN_mod_lshift1_quick(n1, n0, p))
            goto err;
        if (!BN_mod_add_quick(n0, n0, n1, p))
            goto err;
        if (!BN_mod_add_quick(n1, n0, &group->a, p))
            goto err;
        /* n1 = 3 * X_a^2 + a_curve */
    } else if (group->a_is_minus3) {
        if (!field_sqr(group, n1, &a->Z, ctx))
            goto err;
        if (!BN_mod_add_quick(n0, &a->X, n1, p))
            goto err;
        if (!BN_mod_sub_quick(n2, &a->X, n1, p))
            goto err;
        if (!field_mul(group, n1, n0, n2, ctx))
            goto err;
        if (!BN_mod_lshift1_quick(n0, n1, p))
            goto err;
        if (!BN_mod_add_quick(n1, n0, n1, p))
            goto err;
        /*-
         * n1 = 3 * (X_a + Z_a^2) * (X_a - Z_a^2)
         *    = 3 * X_a^2 - 3 * Z_a^4
         */
    } else {
        if (!field_sqr(group, n0, &a->X, ctx))
            goto err;
        if (!BN_mod_lshift1_quick(n1, n0, p))
            goto err;
        if (!BN_mod_add_quick(n0, n0, n1, p))
            goto err;
        if (!field_sqr(group, n1, &a->Z, ctx))
            goto err;
        if (!field_sqr(group, n1, n1, ctx))
            goto err;
        if (!field_mul(group, n1, n1, &group->a, ctx))
            goto err;
        if (!BN_mod_add_quick(n1, n1, n0, p))
            goto err;
        /* n1 = 3 * X_a^2 + a_curve * Z_a^4 */
    }

    /* Z_r */
    if (a->Z_is_one) {
        if (!BN_copy(n0, &a->Y))
            goto err;
    } else {
        if (!field_mul(group, n0, &a->Y, &a->Z, ctx))
            goto err;
    }
    if (!BN_mod_lshift1_quick(&r->Z, n0, p))
        goto err;
    r->Z_is_one = 0;
    /* Z_r = 2 * Y_a * Z_a */

    /* n2 */
    if (!field_sqr(group, n3, &a->Y, ctx))
        goto err;
    if (!field_mul(group, n2, &a->X, n3, ctx))
        goto err;
    if (!BN_mod_lshift_quick(n2, n2, 2, p))
        goto err;
    /* n2 = 4 * X_a * Y_a^2 */

    /* X_r */
    if (!BN_mod_lshift1_quick(n0, n2, p))
        goto err;
    if (!field_sqr(group, &r->X, n1, ctx))
        goto err;
    if (!BN_mod_sub_quick(&r->X, &r->X, n0, p))
        goto err;
    /* X_r = n1^2 - 2 * n2 */

    /* n3 */
    if (!field_sqr(group, n0, n3, ctx))
        goto err;
    if (!BN_mod_lshift_quick(n3, n0, 3, p))
        goto err;
    /* n3 = 8 * Y_a^4 */

    /* Y_r */
    if (!BN_mod_sub_quick(n0, n2, &r->X, p))
        goto err;
    if (!field_mul(group, n0, n1, n0, ctx))
        goto err;
    if (!BN_mod_sub_quick(&r->Y, n0, n3, p))
        goto err;
    /* Y_r = n1 * (n2 - X_r) - n3 */

    ret = 1;

err:
    BN_CTX_end(ctx);
    if (new_ctx != NULL)
        BN_CTX_free(new_ctx);
    return ret;
}
Exemple #30
0
static int rsa_ossl_public_encrypt(int flen, const unsigned char *from,
                                  unsigned char *to, RSA *rsa, int padding)
{
    BIGNUM *f, *ret;
    int i, num = 0, r = -1;
    unsigned char *buf = NULL;
    BN_CTX *ctx = NULL;

    if (BN_num_bits(rsa->n) > OPENSSL_RSA_MAX_MODULUS_BITS) {
        RSAerr(RSA_F_RSA_OSSL_PUBLIC_ENCRYPT, RSA_R_MODULUS_TOO_LARGE);
        return -1;
    }

    if (BN_ucmp(rsa->n, rsa->e) <= 0) {
        RSAerr(RSA_F_RSA_OSSL_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE);
        return -1;
    }

    /* for large moduli, enforce exponent limit */
    if (BN_num_bits(rsa->n) > OPENSSL_RSA_SMALL_MODULUS_BITS) {
        if (BN_num_bits(rsa->e) > OPENSSL_RSA_MAX_PUBEXP_BITS) {
            RSAerr(RSA_F_RSA_OSSL_PUBLIC_ENCRYPT, RSA_R_BAD_E_VALUE);
            return -1;
        }
    }

    if ((ctx = BN_CTX_new()) == NULL)
        goto err;
    BN_CTX_start(ctx);
    f = BN_CTX_get(ctx);
    ret = BN_CTX_get(ctx);
    num = BN_num_bytes(rsa->n);
    buf = OPENSSL_malloc(num);
    if (ret == NULL || buf == NULL) {
        RSAerr(RSA_F_RSA_OSSL_PUBLIC_ENCRYPT, ERR_R_MALLOC_FAILURE);
        goto err;
    }

    switch (padding) {
    case RSA_PKCS1_PADDING:
        i = RSA_padding_add_PKCS1_type_2(buf, num, from, flen);
        break;
    case RSA_PKCS1_OAEP_PADDING:
        i = RSA_padding_add_PKCS1_OAEP(buf, num, from, flen, NULL, 0);
        break;
    case RSA_SSLV23_PADDING:
        i = RSA_padding_add_SSLv23(buf, num, from, flen);
        break;
    case RSA_NO_PADDING:
        i = RSA_padding_add_none(buf, num, from, flen);
        break;
    default:
        RSAerr(RSA_F_RSA_OSSL_PUBLIC_ENCRYPT, RSA_R_UNKNOWN_PADDING_TYPE);
        goto err;
    }
    if (i <= 0)
        goto err;

    if (BN_bin2bn(buf, num, f) == NULL)
        goto err;

    if (BN_ucmp(f, rsa->n) >= 0) {
        /* usually the padding functions would catch this */
        RSAerr(RSA_F_RSA_OSSL_PUBLIC_ENCRYPT,
               RSA_R_DATA_TOO_LARGE_FOR_MODULUS);
        goto err;
    }

    if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
        if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n, rsa->lock,
                                    rsa->n, ctx))
            goto err;

    if (!rsa->meth->bn_mod_exp(ret, f, rsa->e, rsa->n, ctx,
                               rsa->_method_mod_n))
        goto err;

    /*
     * BN_bn2binpad puts in leading 0 bytes if the number is less than
     * the length of the modulus.
     */
    r = BN_bn2binpad(ret, to, num);
 err:
    if (ctx != NULL)
        BN_CTX_end(ctx);
    BN_CTX_free(ctx);
    OPENSSL_clear_free(buf, num);
    return r;
}