summaryrefslogtreecommitdiff
path: root/test/exptest.c
blob: e6f52139a197da7619a59f0a75e2c20aa59ef373 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
/*
 * Copyright 1995-2017 The OpenSSL Project Authors. All Rights Reserved.
 *
 * Licensed under the OpenSSL license (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 <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "../e_os.h"

#include <openssl/bio.h>
#include <openssl/bn.h>
#include <openssl/rand.h>
#include <openssl/err.h>

#include "testutil.h"

#define NUM_BITS        (BN_BITS2 * 4)

#define BN_print_var(v) test_output_bignum(#v, v)

/*
 * Test that r == 0 in test_exp_mod_zero(). Returns one on success,
 * returns zero and prints debug output otherwise.
 */
static int a_is_zero_mod_one(const char *method, const BIGNUM *r,
                             const BIGNUM *a)
{
    if (!BN_is_zero(r)) {
        TEST_error("%s failed: a ** 0 mod 1 = r (should be 0)", method);
        BN_print_var(a);
        BN_print_var(r);
        return 0;
    }
    return 1;
}

/*
 * test_mod_exp_zero tests that x**0 mod 1 == 0. It returns zero on success.
 */
static int test_mod_exp_zero()
{
    BIGNUM *a = NULL, *p = NULL, *m = NULL;
    BIGNUM *r = NULL;
    BN_ULONG one_word = 1;
    BN_CTX *ctx = BN_CTX_new();
    int ret = 1, failed = 0;

    if (!TEST_ptr(m = BN_new())
        || !TEST_ptr(a = BN_new())
        || !TEST_ptr(p = BN_new())
        || !TEST_ptr(r = BN_new()))
        goto err;

    BN_one(m);
    BN_one(a);
    BN_zero(p);

    if (!TEST_true(BN_rand(a, 1024, BN_RAND_TOP_ONE, BN_RAND_BOTTOM_ANY)))
        goto err;

    if (!TEST_true(BN_mod_exp(r, a, p, m, ctx)))
        goto err;

    if (!TEST_true(a_is_zero_mod_one("BN_mod_exp", r, a)))
        failed = 1;

    if (!TEST_true(BN_mod_exp_recp(r, a, p, m, ctx)))
        goto err;

    if (!TEST_true(a_is_zero_mod_one("BN_mod_exp_recp", r, a)))
        failed = 1;

    if (!TEST_true(BN_mod_exp_simple(r, a, p, m, ctx)))
        goto err;

    if (!TEST_true(a_is_zero_mod_one("BN_mod_exp_simple", r, a)))
        failed = 1;

    if (!TEST_true(BN_mod_exp_mont(r, a, p, m, ctx, NULL)))
        goto err;

    if (!TEST_true(a_is_zero_mod_one("BN_mod_exp_mont", r, a)))
        failed = 1;

    if (!TEST_true(BN_mod_exp_mont_consttime(r, a, p, m, ctx, NULL)))
        goto err;

    if (!TEST_true(a_is_zero_mod_one("BN_mod_exp_mont_consttime", r, a)))
        failed = 1;

    /*
     * A different codepath exists for single word multiplication
     * in non-constant-time only.
     */
    if (!TEST_true(BN_mod_exp_mont_word(r, one_word, p, m, ctx, NULL)))
        goto err;

    if (!TEST_BN_eq_zero(r)) {
        TEST_error("BN_mod_exp_mont_word failed: "
                   "1 ** 0 mod 1 = r (should be 0)");
        BN_print_var(r);
        goto err;
    }

    ret = !failed;
 err:
    BN_free(r);
    BN_free(a);
    BN_free(p);
    BN_free(m);
    BN_CTX_free(ctx);

    return ret;
}

static int test_mod_exp(int round)
{
    BN_CTX *ctx;
    unsigned char c;
    int ret = 0;
    BIGNUM *r_mont = NULL;
    BIGNUM *r_mont_const = NULL;
    BIGNUM *r_recp = NULL;
    BIGNUM *r_simple = NULL;
    BIGNUM *a = NULL;
    BIGNUM *b = NULL;
    BIGNUM *m = NULL;

    if (!TEST_ptr(ctx = BN_CTX_new()))
        goto err;

    if (!TEST_ptr(r_mont = BN_new())
        || !TEST_ptr(r_mont_const = BN_new())
        || !TEST_ptr(r_recp = BN_new())
        || !TEST_ptr(r_simple = BN_new())
        || !TEST_ptr(a = BN_new())
        || !TEST_ptr(b = BN_new())
        || !TEST_ptr(m = BN_new()))
        goto err;

    RAND_bytes(&c, 1);
    c = (c % BN_BITS) - BN_BITS2;
    BN_rand(a, NUM_BITS + c, BN_RAND_TOP_ONE, BN_RAND_BOTTOM_ANY);

    RAND_bytes(&c, 1);
    c = (c % BN_BITS) - BN_BITS2;
    BN_rand(b, NUM_BITS + c, BN_RAND_TOP_ONE, BN_RAND_BOTTOM_ANY);

    RAND_bytes(&c, 1);
    c = (c % BN_BITS) - BN_BITS2;
    BN_rand(m, NUM_BITS + c, BN_RAND_TOP_ONE, BN_RAND_BOTTOM_ODD);

    BN_mod(a, a, m, ctx);
    BN_mod(b, b, m, ctx);

    if (!TEST_true(BN_mod_exp_mont(r_mont, a, b, m, ctx, NULL))
        || !TEST_true(BN_mod_exp_recp(r_recp, a, b, m, ctx))
        || !TEST_true(BN_mod_exp_simple(r_simple, a, b, m, ctx))
        || !TEST_true(BN_mod_exp_mont_consttime(r_mont_const, a, b, m, ctx, NULL)))
        goto err;

    if (!TEST_BN_eq(r_simple, r_mont)
        || !TEST_BN_eq(r_simple, r_recp)
        || !TEST_BN_eq(r_simple, r_mont_const)) {
        if (BN_cmp(r_simple, r_mont) != 0)
            TEST_info("simple and mont results differ");
        if (BN_cmp(r_simple, r_mont_const) != 0)
            TEST_info("simple and mont const time results differ");
        if (BN_cmp(r_simple, r_recp) != 0)
            TEST_info("simple and recp results differ");

        BN_print_var(a);
        BN_print_var(b);
        BN_print_var(m);
        BN_print_var(r_simple);
        BN_print_var(r_recp);
        BN_print_var(r_mont);
        BN_print_var(r_mont_const);
        goto err;
    }

    ret = 1;
 err:
    BN_free(r_mont);
    BN_free(r_mont_const);
    BN_free(r_recp);
    BN_free(r_simple);
    BN_free(a);
    BN_free(b);
    BN_free(m);
    BN_CTX_free(ctx);

    return ret;
}

void register_tests(void)
{
    ADD_TEST(test_mod_exp_zero);
    ADD_ALL_TESTS(test_mod_exp, 200);
}