373 lines
10 KiB
C
373 lines
10 KiB
C
|
/*
|
||
|
|
* Copyright 2011-2021 The OpenSSL Project Authors. All Rights Reserved.
|
||
|
|
* Copyright (c) 2002, Oracle and/or its affiliates. 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
|
||
|
|
*/
|
||
|
|
|
||
|
|
/*
|
||
|
|
* ECDSA low level APIs are deprecated for public use, but still ok for
|
||
|
|
* internal use.
|
||
|
|
*/
|
||
|
|
#include "internal/deprecated.h"
|
||
|
|
|
||
|
|
#include <openssl/err.h>
|
||
|
|
#include <openssl/symhacks.h>
|
||
|
|
|
||
|
|
#include "ec_local.h"
|
||
|
|
|
||
|
|
int ossl_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;
|
||
|
|
|
||
|
|
if (ctx == NULL) {
|
||
|
|
ctx = new_ctx = BN_CTX_new_ex(group->libctx);
|
||
|
|
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;
|
||
|
|
}
|
||
|
|
|
||
|
|
ERR_set_mark();
|
||
|
|
if (!BN_mod_sqrt(y, tmp1, group->field, ctx)) {
|
||
|
|
#ifndef FIPS_MODULE
|
||
|
|
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_pop_to_mark();
|
||
|
|
ERR_raise(ERR_LIB_EC, EC_R_INVALID_COMPRESSED_POINT);
|
||
|
|
} else
|
||
|
|
#endif
|
||
|
|
{
|
||
|
|
ERR_clear_last_mark();
|
||
|
|
ERR_raise(ERR_LIB_EC, ERR_R_BN_LIB);
|
||
|
|
}
|
||
|
|
goto err;
|
||
|
|
}
|
||
|
|
ERR_clear_last_mark();
|
||
|
|
|
||
|
|
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)
|
||
|
|
ERR_raise(ERR_LIB_EC, EC_R_INVALID_COMPRESSION_BIT);
|
||
|
|
else
|
||
|
|
/*
|
||
|
|
* BN_mod_sqrt() should have caught this error (not a square)
|
||
|
|
*/
|
||
|
|
ERR_raise(ERR_LIB_EC, EC_R_INVALID_COMPRESSED_POINT);
|
||
|
|
goto err;
|
||
|
|
}
|
||
|
|
if (!BN_usub(y, group->field, y))
|
||
|
|
goto err;
|
||
|
|
}
|
||
|
|
if (y_bit != BN_is_odd(y)) {
|
||
|
|
ERR_raise(ERR_LIB_EC, ERR_R_INTERNAL_ERROR);
|
||
|
|
goto err;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (!EC_POINT_set_affine_coordinates(group, point, x, y, ctx))
|
||
|
|
goto err;
|
||
|
|
|
||
|
|
ret = 1;
|
||
|
|
|
||
|
|
err:
|
||
|
|
BN_CTX_end(ctx);
|
||
|
|
BN_CTX_free(new_ctx);
|
||
|
|
return ret;
|
||
|
|
}
|
||
|
|
|
||
|
|
size_t ossl_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)) {
|
||
|
|
ERR_raise(ERR_LIB_EC, 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) {
|
||
|
|
ERR_raise(ERR_LIB_EC, 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) {
|
||
|
|
ERR_raise(ERR_LIB_EC, EC_R_BUFFER_TOO_SMALL);
|
||
|
|
goto err;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (ctx == NULL) {
|
||
|
|
ctx = new_ctx = BN_CTX_new_ex(group->libctx);
|
||
|
|
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(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) {
|
||
|
|
ERR_raise(ERR_LIB_EC, 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) {
|
||
|
|
ERR_raise(ERR_LIB_EC, 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) {
|
||
|
|
ERR_raise(ERR_LIB_EC, ERR_R_INTERNAL_ERROR);
|
||
|
|
goto err;
|
||
|
|
}
|
||
|
|
while (skip > 0) {
|
||
|
|
buf[i++] = 0;
|
||
|
|
skip--;
|
||
|
|
}
|
||
|
|
skip = BN_bn2bin(y, buf + i);
|
||
|
|
i += skip;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (i != ret) {
|
||
|
|
ERR_raise(ERR_LIB_EC, ERR_R_INTERNAL_ERROR);
|
||
|
|
goto err;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if (used_ctx)
|
||
|
|
BN_CTX_end(ctx);
|
||
|
|
BN_CTX_free(new_ctx);
|
||
|
|
return ret;
|
||
|
|
|
||
|
|
err:
|
||
|
|
if (used_ctx)
|
||
|
|
BN_CTX_end(ctx);
|
||
|
|
BN_CTX_free(new_ctx);
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
int ossl_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) {
|
||
|
|
ERR_raise(ERR_LIB_EC, 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)) {
|
||
|
|
ERR_raise(ERR_LIB_EC, EC_R_INVALID_ENCODING);
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
if ((form == 0 || form == POINT_CONVERSION_UNCOMPRESSED) && y_bit) {
|
||
|
|
ERR_raise(ERR_LIB_EC, EC_R_INVALID_ENCODING);
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (form == 0) {
|
||
|
|
if (len != 1) {
|
||
|
|
ERR_raise(ERR_LIB_EC, 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) {
|
||
|
|
ERR_raise(ERR_LIB_EC, EC_R_INVALID_ENCODING);
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (ctx == NULL) {
|
||
|
|
ctx = new_ctx = BN_CTX_new_ex(group->libctx);
|
||
|
|
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, field_len, x))
|
||
|
|
goto err;
|
||
|
|
if (BN_ucmp(x, group->field) >= 0) {
|
||
|
|
ERR_raise(ERR_LIB_EC, EC_R_INVALID_ENCODING);
|
||
|
|
goto err;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (form == POINT_CONVERSION_COMPRESSED) {
|
||
|
|
if (!EC_POINT_set_compressed_coordinates(group, point, x, y_bit, ctx))
|
||
|
|
goto err;
|
||
|
|
} else {
|
||
|
|
if (!BN_bin2bn(buf + 1 + field_len, field_len, y))
|
||
|
|
goto err;
|
||
|
|
if (BN_ucmp(y, group->field) >= 0) {
|
||
|
|
ERR_raise(ERR_LIB_EC, EC_R_INVALID_ENCODING);
|
||
|
|
goto err;
|
||
|
|
}
|
||
|
|
if (form == POINT_CONVERSION_HYBRID) {
|
||
|
|
if (y_bit != BN_is_odd(y)) {
|
||
|
|
ERR_raise(ERR_LIB_EC, EC_R_INVALID_ENCODING);
|
||
|
|
goto err;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* EC_POINT_set_affine_coordinates is responsible for checking that
|
||
|
|
* the point is on the curve.
|
||
|
|
*/
|
||
|
|
if (!EC_POINT_set_affine_coordinates(group, point, x, y, ctx))
|
||
|
|
goto err;
|
||
|
|
}
|
||
|
|
|
||
|
|
ret = 1;
|
||
|
|
|
||
|
|
err:
|
||
|
|
BN_CTX_end(ctx);
|
||
|
|
BN_CTX_free(new_ctx);
|
||
|
|
return ret;
|
||
|
|
}
|