1 /*
2 * Copyright 2017-2021 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 * https://www.openssl.org/source/license.html
8 * or in the file LICENSE in the source distribution.
9 */
10
11 #include "internal/nelem.h"
12 #include "testutil.h"
13
14 #include <stdio.h>
15 #include <stdlib.h>
16 #include <string.h>
17 #include <ctype.h>
18
19 #define NUM_REPEATS "1000000"
20
21 static ossl_intmax_t num_repeats;
22 static int print_mode = 0;
23
24 #ifndef OPENSSL_NO_EC
25 # include <openssl/ec.h>
26 # include <openssl/err.h>
27 # include <openssl/obj_mac.h>
28 # include <openssl/objects.h>
29 # include <openssl/rand.h>
30 # include <openssl/bn.h>
31 # include <openssl/opensslconf.h>
32
33 static const char *kP256DefaultResult =
34 "A1E24B223B8E81BC1FFF99BAFB909EDB895FACDE7D6DA5EF5E7B3255FB378E0F";
35
36 /*
37 * Perform a deterministic walk on the curve, by starting from |point| and
38 * using the X-coordinate of the previous point as the next scalar for
39 * point multiplication.
40 * Returns the X-coordinate of the end result or NULL on error.
41 */
walk_curve(const EC_GROUP * group,EC_POINT * point,ossl_intmax_t num)42 static BIGNUM *walk_curve(const EC_GROUP *group, EC_POINT *point,
43 ossl_intmax_t num)
44 {
45 BIGNUM *scalar = NULL;
46 ossl_intmax_t i;
47
48 if (!TEST_ptr(scalar = BN_new())
49 || !TEST_true(EC_POINT_get_affine_coordinates(group, point, scalar,
50 NULL, NULL)))
51 goto err;
52
53 for (i = 0; i < num; i++) {
54 if (!TEST_true(EC_POINT_mul(group, point, NULL, point, scalar, NULL))
55 || !TEST_true(EC_POINT_get_affine_coordinates(group, point,
56 scalar,
57 NULL, NULL)))
58 goto err;
59 }
60 return scalar;
61
62 err:
63 BN_free(scalar);
64 return NULL;
65 }
66
test_curve(void)67 static int test_curve(void)
68 {
69 EC_GROUP *group = NULL;
70 EC_POINT *point = NULL;
71 BIGNUM *result = NULL, *expected_result = NULL;
72 int ret = 0;
73
74 /*
75 * We currently hard-code P-256, though adaptation to other curves.
76 * would be straightforward.
77 */
78 if (!TEST_ptr(group = EC_GROUP_new_by_curve_name(NID_X9_62_prime256v1))
79 || !TEST_ptr(point = EC_POINT_dup(EC_GROUP_get0_generator(group),
80 group))
81 || !TEST_ptr(result = walk_curve(group, point, num_repeats)))
82 return 0;
83
84 if (print_mode) {
85 BN_print(bio_out, result);
86 BIO_printf(bio_out, "\n");
87 ret = 1;
88 } else {
89 if (!TEST_true(BN_hex2bn(&expected_result, kP256DefaultResult))
90 || !TEST_ptr(expected_result)
91 || !TEST_BN_eq(result, expected_result))
92 goto err;
93 ret = 1;
94 }
95
96 err:
97 EC_GROUP_free(group);
98 EC_POINT_free(point);
99 BN_free(result);
100 BN_free(expected_result);
101 return ret;
102 }
103 #endif
104
105 typedef enum OPTION_choice {
106 OPT_ERR = -1,
107 OPT_EOF = 0,
108 OPT_NUM_REPEATS,
109 OPT_TEST_ENUM
110 } OPTION_CHOICE;
111
test_get_options(void)112 const OPTIONS *test_get_options(void)
113 {
114 static const OPTIONS test_options[] = {
115 OPT_TEST_OPTIONS_DEFAULT_USAGE,
116 { "num", OPT_NUM_REPEATS, 'M', "Number of repeats" },
117 { NULL }
118 };
119 return test_options;
120 }
121
122 /*
123 * Stress test the curve. If the '-num' argument is given, runs the loop
124 * |num| times and prints the resulting X-coordinate. Otherwise runs the test
125 * the default number of times and compares against the expected result.
126 */
setup_tests(void)127 int setup_tests(void)
128 {
129 OPTION_CHOICE o;
130
131 if (!opt_intmax(NUM_REPEATS, &num_repeats)) {
132 TEST_error("Cannot parse " NUM_REPEATS);
133 return 0;
134 }
135
136 while ((o = opt_next()) != OPT_EOF) {
137 switch (o) {
138 case OPT_NUM_REPEATS:
139 if (!opt_intmax(opt_arg(), &num_repeats)
140 || num_repeats < 0)
141 return 0;
142 print_mode = 1;
143 break;
144 case OPT_TEST_CASES:
145 break;
146 default:
147 case OPT_ERR:
148 return 0;
149 }
150 }
151
152 #ifndef OPENSSL_NO_EC
153 ADD_TEST(test_curve);
154 #endif
155 return 1;
156 }
157
