/*
* Copyright 2019 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the Apache License 2.0 (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include <stdlib.h>
#include <string.h>
#include <openssl/err.h>
#include <openssl/rand.h>
#include "ec_local.h"
#include "s390x_arch.h"
/* Size of parameter blocks */
#define S390X_SIZE_PARAM 4096
/* Size of fields in parameter blocks */
#define S390X_SIZE_P256 32
#define S390X_SIZE_P384 48
#define S390X_SIZE_P521 80
/* Offsets of fields in PCC parameter blocks */
#define S390X_OFF_RES_X(n) (0 * n)
#define S390X_OFF_RES_Y(n) (1 * n)
#define S390X_OFF_SRC_X(n) (2 * n)
#define S390X_OFF_SRC_Y(n) (3 * n)
#define S390X_OFF_SCALAR(n) (4 * n)
/* Offsets of fields in KDSA parameter blocks */
#define S390X_OFF_R(n) (0 * n)
#define S390X_OFF_S(n) (1 * n)
#define S390X_OFF_H(n) (2 * n)
#define S390X_OFF_K(n) (3 * n)
#define S390X_OFF_X(n) (3 * n)
#define S390X_OFF_RN(n) (4 * n)
#define S390X_OFF_Y(n) (4 * n)
static int ec_GFp_s390x_nistp_mul(const EC_GROUP *group, EC_POINT *r,
const BIGNUM *scalar,
size_t num, const EC_POINT *points[],
const BIGNUM *scalars[],
BN_CTX *ctx, unsigned int fc, int len)
{
unsigned char param[S390X_SIZE_PARAM];
BIGNUM *x, *y;
const EC_POINT *point_ptr = NULL;
const BIGNUM *scalar_ptr = NULL;
BN_CTX *new_ctx = NULL;
int rc = -1;
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 (x == NULL || y == NULL) {
rc = 0;
goto ret;
}
/*
* Use PCC for EC keygen and ECDH key derivation:
* scalar * generator and scalar * peer public key,
* scalar in [0,order).
*/
if ((scalar != NULL && num == 0 && BN_is_negative(scalar) == 0)
|| (scalar == NULL && num == 1 && BN_is_negative(scalars[0]) == 0)) {
if (num == 0) {
point_ptr = EC_GROUP_get0_generator(group);
scalar_ptr = scalar;
} else {
point_ptr = points[0];
scalar_ptr = scalars[0];
}
if (EC_POINT_is_at_infinity(group, point_ptr) == 1
|| BN_is_zero(scalar_ptr)) {
rc = EC_POINT_set_to_infinity(group, r);
goto ret;
}
memset(¶m, 0, sizeof(param));
if (group->meth->point_get_affine_coordinates(group, point_ptr,
x, y, ctx) != 1
|| BN_bn2binpad(x, param + S390X_OFF_SRC_X(len), len) == -1
|| BN_bn2binpad(y, param + S390X_OFF_SRC_Y(len), len) == -1
|| BN_bn2binpad(scalar_ptr,
param + S390X_OFF_SCALAR(len), len) == -1
|| s390x_pcc(fc, param) != 0
|| BN_bin2bn(param + S390X_OFF_RES_X(len), len, x) == NULL
|| BN_bin2bn(param + S390X_OFF_RES_Y(len), len, y) == NULL
|| group->meth->point_set_affine_coordinates(group, r,
x, y, ctx) != 1)
goto ret;
rc = 1;
}
ret:
/* Otherwise use default. */
if (rc == -1)
rc = ec_wNAF_mul(group, r, scalar, num, points, scalars, ctx);
OPENSSL_cleanse(param + S390X_OFF_SCALAR(len), len);
BN_CTX_end(ctx);
BN_CTX_free(new_ctx);
return rc;
}
static ECDSA_SIG *ecdsa_s390x_nistp_sign_sig(const unsigned char *dgst,
int dgstlen,
const BIGNUM *kinv,
const BIGNUM *r,
EC_KEY *eckey,
unsigned int fc, int len)
{
unsigned char param[S390X_SIZE_PARAM];
int ok = 0;
BIGNUM *k;
ECDSA_SIG *sig;
const EC_GROUP *group;
const BIGNUM *privkey;
int off;
group = EC_KEY_get0_group(eckey);
privkey = EC_KEY_get0_private_key(eckey);
if (group == NULL || privkey == NULL) {
ECerr(EC_F_ECDSA_S390X_NISTP_SIGN_SIG, EC_R_MISSING_PARAMETERS);
return NULL;
}
if (!EC_KEY_can_sign(eckey)) {
ECerr(EC_F_ECDSA_S390X_NISTP_SIGN_SIG,
EC_R_CURVE_DOES_NOT_SUPPORT_SIGNING);
return NULL;
}
k = BN_secure_new();
sig = ECDSA_SIG_new();
if (k == NULL || sig == NULL) {
ECerr(EC_F_ECDSA_S390X_NISTP_SIGN_SIG, ERR_R_MALLOC_FAILURE);
goto ret;
}
sig->r = BN_new();
sig->s = BN_new();
if (sig->r == NULL || sig->s == NULL) {
ECerr(EC_F_ECDSA_S390X_NISTP_SIGN_SIG, ERR_R_MALLOC_FAILURE);
goto ret;
}
memset(param, 0, sizeof(param));
off = len - (dgstlen > len ? len : dgstlen);
memcpy(param + S390X_OFF_H(len) + off, dgst, len - off);
if (BN_bn2binpad(privkey, param + S390X_OFF_K(len), len) == -1) {
ECerr(EC_F_ECDSA_S390X_NISTP_SIGN_SIG, ERR_R_BN_LIB);
goto ret;
}
if (r == NULL || kinv == NULL) {
/*
* Generate random k and copy to param param block. RAND_priv_bytes
* is used instead of BN_priv_rand_range or BN_generate_dsa_nonce
* because kdsa instruction constructs an in-range, invertible nonce
* internally implementing counter-measures for RNG weakness.
*/
if (RAND_priv_bytes(param + S390X_OFF_RN(len), len) != 1) {
ECerr(EC_F_ECDSA_S390X_NISTP_SIGN_SIG,
EC_R_RANDOM_NUMBER_GENERATION_FAILED);
goto ret;
}
} else {
/* Reconstruct k = (k^-1)^-1. */
if (ec_group_do_inverse_ord(group, k, kinv, NULL) == 0
|| BN_bn2binpad(k, param + S390X_OFF_RN(len), len) == -1) {
ECerr(EC_F_ECDSA_S390X_NISTP_SIGN_SIG, ERR_R_BN_LIB);
goto ret;
}
/* Turns KDSA internal nonce-generation off. */
fc |= S390X_KDSA_D;
}
if (s390x_kdsa(fc, param, NULL, 0) != 0) {
ECerr(EC_F_ECDSA_S390X_NISTP_SIGN_SIG, ERR_R_ECDSA_LIB);
goto ret;
}
if (BN_bin2bn(param + S390X_OFF_R(len), len, sig->r) == NULL
|| BN_bin2bn(param + S390X_OFF_S(len), len, sig->s) == NULL) {
ECerr(EC_F_ECDSA_S390X_NISTP_SIGN_SIG, ERR_R_BN_LIB);
goto ret;
}
ok = 1;
ret:
OPENSSL_cleanse(param + S390X_OFF_K(len), 2 * len);
if (ok != 1) {
ECDSA_SIG_free(sig);
sig = NULL;
}
BN_clear_free(k);
return sig;
}
static int ecdsa_s390x_nistp_verify_sig(const unsigned char *dgst, int dgstlen,
const ECDSA_SIG *sig, EC_KEY *eckey,
unsigned int fc, int len)
{
unsigned char param[S390X_SIZE_PARAM];
int rc = -1;
BN_CTX *ctx;
BIGNUM *x, *y;
const EC_GROUP *group;
const EC_POINT *pubkey;
int off;
group = EC_KEY_get0_group(eckey);
pubkey = EC_KEY_get0_public_key(eckey);
if (eckey == NULL || group == NULL || pubkey == NULL || sig == NULL) {
ECerr(EC_F_ECDSA_S390X_NISTP_VERIFY_SIG, EC_R_MISSING_PARAMETERS);
return -1;
}
if (!EC_KEY_can_sign(eckey)) {
ECerr(EC_F_ECDSA_S390X_NISTP_VERIFY_SIG,
EC_R_CURVE_DOES_NOT_SUPPORT_SIGNING);
return -1;
}
ctx = BN_CTX_new();
if (ctx == NULL) {
ECerr(EC_F_ECDSA_S390X_NISTP_VERIFY_SIG, ERR_R_MALLOC_FAILURE);
return -1;
}
BN_CTX_start(ctx);
x = BN_CTX_get(ctx);
y = BN_CTX_get(ctx);
if (x == NULL || y == NULL) {
ECerr(EC_F_ECDSA_S390X_NISTP_VERIFY_SIG, ERR_R_MALLOC_FAILURE);
goto ret;
}
memset(param, 0, sizeof(param));
off = len - (dgstlen > len ? len : dgstlen);
memcpy(param + S390X_OFF_H(len) + off, dgst, len - off);
if (group->meth->point_get_affine_coordinates(group, pubkey,
x, y, ctx) != 1
|| BN_bn2binpad(sig->r, param + S390X_OFF_R(len), len) == -1
|| BN_bn2binpad(sig->s, param + S390X_OFF_S(len), len) == -1
|| BN_bn2binpad(x, param + S390X_OFF_X(len), len) == -1
|| BN_bn2binpad(y, param + S390X_OFF_Y(len), len) == -1) {
ECerr(EC_F_ECDSA_S390X_NISTP_VERIFY_SIG, ERR_R_BN_LIB);
goto ret;
}
rc = s390x_kdsa(fc, param, NULL, 0) == 0 ? 1 : 0;
ret:
BN_CTX_end(ctx);
BN_CTX_free(ctx);
return rc;
}
#define EC_GFP_S390X_NISTP_METHOD(bits) \
\
static int ec_GFp_s390x_nistp##bits##_mul(const EC_GROUP *group, \
EC_POINT *r, \
const BIGNUM *scalar, \
size_t num, \
const EC_POINT *points[], \
const BIGNUM *scalars[], \
BN_CTX *ctx) \
{ \
return ec_GFp_s390x_nistp_mul(group, r, scalar, num, points, \
scalars, ctx, \
S390X_SCALAR_MULTIPLY_P##bits, \
S390X_SIZE_P##bits); \
} \
\
static ECDSA_SIG *ecdsa_s390x_nistp##bits##_sign_sig(const unsigned \
char *dgst, \
int dgstlen, \
const BIGNUM *kinv,\
const BIGNUM *r, \
EC_KEY *eckey) \
{ \
return ecdsa_s390x_nistp_sign_sig(dgst, dgstlen, kinv, r, eckey, \
S390X_ECDSA_SIGN_P##bits, \
S390X_SIZE_P##bits); \
} \
\
static int ecdsa_s390x_nistp##bits##_verify_sig(const \
unsigned char *dgst, \
int dgstlen, \
const ECDSA_SIG *sig, \
EC_KEY *eckey) \
{ \
return ecdsa_s390x_nistp_verify_sig(dgst, dgstlen, sig, eckey, \
S390X_ECDSA_VERIFY_P##bits, \
S390X_SIZE_P##bits); \
} \
\
const EC_METHOD *EC_GFp_s390x_nistp##bits##_method(void) \
{ \
static const EC_METHOD EC_GFp_s390x_nistp##bits##_meth = { \
EC_FLAGS_DEFAULT_OCT, \
NID_X9_62_prime_field, \
ec_GFp_simple_group_init, \
ec_GFp_simple_group_finish, \
ec_GFp_simple_group_clear_finish, \
ec_GFp_simple_group_copy, \
ec_GFp_simple_group_set_curve, \
ec_GFp_simple_group_get_curve, \
ec_GFp_simple_group_get_degree, \
ec_group_simple_order_bits, \
ec_GFp_simple_group_check_discriminant, \
ec_GFp_simple_point_init, \
ec_GFp_simple_point_finish, \
ec_GFp_simple_point_clear_finish, \
ec_GFp_simple_point_copy, \
ec_GFp_simple_point_set_to_infinity, \
ec_GFp_simple_set_Jprojective_coordinates_GFp, \
ec_GFp_simple_get_Jprojective_coordinates_GFp, \
ec_GFp_simple_point_set_affine_coordinates, \
ec_GFp_simple_point_get_affine_coordinates, \
NULL, /* point_set_compressed_coordinates */ \
NULL, /* point2oct */ \
NULL, /* oct2point */ \
ec_GFp_simple_add, \
ec_GFp_simple_dbl, \
ec_GFp_simple_invert, \
ec_GFp_simple_is_at_infinity, \
ec_GFp_simple_is_on_curve, \
ec_GFp_simple_cmp, \
ec_GFp_simple_make_affine, \
ec_GFp_simple_points_make_affine, \
ec_GFp_s390x_nistp##bits##_mul, \
NULL, /* precompute_mult */ \
NULL, /* have_precompute_mult */ \
ec_GFp_simple_field_mul, \
ec_GFp_simple_field_sqr, \
NULL, /* field_div */ \
ec_GFp_simple_field_inv, \
NULL, /* field_encode */ \
NULL, /* field_decode */ \
NULL, /* field_set_to_one */ \
ec_key_simple_priv2oct, \
ec_key_simple_oct2priv, \
NULL, /* set_private */ \
ec_key_simple_generate_key, \
ec_key_simple_check_key, \
ec_key_simple_generate_public_key, \
NULL, /* keycopy */ \
NULL, /* keyfinish */ \
ecdh_simple_compute_key, \
ecdsa_simple_sign_setup, \
ecdsa_s390x_nistp##bits##_sign_sig, \
ecdsa_s390x_nistp##bits##_verify_sig, \
NULL, /* field_inverse_mod_ord */ \
ec_GFp_simple_blind_coordinates, \
ec_GFp_simple_ladder_pre, \
ec_GFp_simple_ladder_step, \
ec_GFp_simple_ladder_post \
}; \
static const EC_METHOD *ret; \
\
if ((OPENSSL_s390xcap_P.pcc[1] \
& S390X_CAPBIT(S390X_SCALAR_MULTIPLY_P##bits)) \
&& (OPENSSL_s390xcap_P.kdsa[0] \
& S390X_CAPBIT(S390X_ECDSA_VERIFY_P##bits)) \
&& (OPENSSL_s390xcap_P.kdsa[0] \
& S390X_CAPBIT(S390X_ECDSA_SIGN_P##bits))) \
ret = &EC_GFp_s390x_nistp##bits##_meth; \
else \
ret = EC_GFp_mont_method(); \
\
return ret; \
}
EC_GFP_S390X_NISTP_METHOD(256)
EC_GFP_S390X_NISTP_METHOD(384)
EC_GFP_S390X_NISTP_METHOD(521)