exptest.c revision 295016 
1/* crypto/bn/exptest.c */
2/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3 * All rights reserved.
4 *
5 * This package is an SSL implementation written
6 * by Eric Young (eay@cryptsoft.com).
7 * The implementation was written so as to conform with Netscapes SSL.
8 *
9 * This library is free for commercial and non-commercial use as long as
10 * the following conditions are aheared to.  The following conditions
11 * apply to all code found in this distribution, be it the RC4, RSA,
12 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
13 * included with this distribution is covered by the same copyright terms
14 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
15 *
16 * Copyright remains Eric Young's, and as such any Copyright notices in
17 * the code are not to be removed.
18 * If this package is used in a product, Eric Young should be given attribution
19 * as the author of the parts of the library used.
20 * This can be in the form of a textual message at program startup or
21 * in documentation (online or textual) provided with the package.
22 *
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
25 * are met:
26 * 1. Redistributions of source code must retain the copyright
27 *    notice, this list of conditions and the following disclaimer.
28 * 2. Redistributions in binary form must reproduce the above copyright
29 *    notice, this list of conditions and the following disclaimer in the
30 *    documentation and/or other materials provided with the distribution.
31 * 3. All advertising materials mentioning features or use of this software
32 *    must display the following acknowledgement:
33 *    "This product includes cryptographic software written by
34 *     Eric Young (eay@cryptsoft.com)"
35 *    The word 'cryptographic' can be left out if the rouines from the library
36 *    being used are not cryptographic related :-).
37 * 4. If you include any Windows specific code (or a derivative thereof) from
38 *    the apps directory (application code) you must include an acknowledgement:
39 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40 *
41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51 * SUCH DAMAGE.
52 *
53 * The licence and distribution terms for any publically available version or
54 * derivative of this code cannot be changed.  i.e. this code cannot simply be
55 * copied and put under another distribution licence
56 * [including the GNU Public Licence.]
57 */
58
59#include <stdio.h>
60#include <stdlib.h>
61#include <string.h>
62
63#include "../e_os.h"
64
65#include <openssl/bio.h>
66#include <openssl/bn.h>
67#include <openssl/rand.h>
68#include <openssl/err.h>
69
70#define NUM_BITS        (BN_BITS*2)
71
72static const char rnd_seed[] =
73    "string to make the random number generator think it has entropy";
74
75/*
76 * Test that r == 0 in test_exp_mod_zero(). Returns one on success,
77 * returns zero and prints debug output otherwise.
78 */
79static int a_is_zero_mod_one(const char *method, const BIGNUM *r,
80                             const BIGNUM *a) {
81    if (!BN_is_zero(r)) {
82        fprintf(stderr, "%s failed:\n", method);
83        fprintf(stderr, "a ** 0 mod 1 = r (should be 0)\n");
84        fprintf(stderr, "a = ");
85        BN_print_fp(stderr, a);
86        fprintf(stderr, "\nr = ");
87        BN_print_fp(stderr, r);
88        fprintf(stderr, "\n");
89        return 0;
90    }
91    return 1;
92}
93
94/*
95 * test_exp_mod_zero tests that x**0 mod 1 == 0. It returns zero on success.
96 */
97static int test_exp_mod_zero()
98{
99    BIGNUM a, p, m;
100    BIGNUM r;
101    BN_ULONG one_word = 1;
102    BN_CTX *ctx = BN_CTX_new();
103    int ret = 1, failed = 0;
104
105    BN_init(&m);
106    BN_one(&m);
107
108    BN_init(&a);
109    BN_one(&a);
110
111    BN_init(&p);
112    BN_zero(&p);
113
114    BN_init(&r);
115
116    if (!BN_rand(&a, 1024, 0, 0))
117        goto err;
118
119    if (!BN_mod_exp(&r, &a, &p, &m, ctx))
120        goto err;
121
122    if (!a_is_zero_mod_one("BN_mod_exp", &r, &a))
123        failed = 1;
124
125    if (!BN_mod_exp_recp(&r, &a, &p, &m, ctx))
126        goto err;
127
128    if (!a_is_zero_mod_one("BN_mod_exp_recp", &r, &a))
129        failed = 1;
130
131    if (!BN_mod_exp_simple(&r, &a, &p, &m, ctx))
132        goto err;
133
134    if (!a_is_zero_mod_one("BN_mod_exp_simple", &r, &a))
135        failed = 1;
136
137    if (!BN_mod_exp_mont(&r, &a, &p, &m, ctx, NULL))
138        goto err;
139
140    if (!a_is_zero_mod_one("BN_mod_exp_mont", &r, &a))
141        failed = 1;
142
143    if (!BN_mod_exp_mont_consttime(&r, &a, &p, &m, ctx, NULL)) {
144        goto err;
145    }
146
147    if (!a_is_zero_mod_one("BN_mod_exp_mont_consttime", &r, &a))
148        failed = 1;
149
150    /*
151     * A different codepath exists for single word multiplication
152     * in non-constant-time only.
153     */
154    if (!BN_mod_exp_mont_word(&r, one_word, &p, &m, ctx, NULL))
155        goto err;
156
157    if (!BN_is_zero(&r)) {
158        fprintf(stderr, "BN_mod_exp_mont_word failed:\n");
159        fprintf(stderr, "1 ** 0 mod 1 = r (should be 0)\n");
160        fprintf(stderr, "r = ");
161        BN_print_fp(stderr, &r);
162        fprintf(stderr, "\n");
163        return 0;
164    }
165
166    ret = failed;
167
168 err:
169    BN_free(&r);
170    BN_free(&a);
171    BN_free(&p);
172    BN_free(&m);
173    BN_CTX_free(ctx);
174
175    return ret;
176}
177
178int main(int argc, char *argv[])
179{
180    BN_CTX *ctx;
181    BIO *out = NULL;
182    int i, ret;
183    unsigned char c;
184    BIGNUM *r_mont, *r_mont_const, *r_recp, *r_simple, *a, *b, *m;
185
186    RAND_seed(rnd_seed, sizeof rnd_seed); /* or BN_rand may fail, and we
187                                           * don't even check its return
188                                           * value (which we should) */
189
190    ERR_load_BN_strings();
191
192    ctx = BN_CTX_new();
193    if (ctx == NULL)
194        EXIT(1);
195    r_mont = BN_new();
196    r_mont_const = BN_new();
197    r_recp = BN_new();
198    r_simple = BN_new();
199    a = BN_new();
200    b = BN_new();
201    m = BN_new();
202    if ((r_mont == NULL) || (r_recp == NULL) || (a == NULL) || (b == NULL))
203        goto err;
204
205    out = BIO_new(BIO_s_file());
206
207    if (out == NULL)
208        EXIT(1);
209    BIO_set_fp(out, stdout, BIO_NOCLOSE);
210
211    for (i = 0; i < 200; i++) {
212        RAND_bytes(&c, 1);
213        c = (c % BN_BITS) - BN_BITS2;
214        BN_rand(a, NUM_BITS + c, 0, 0);
215
216        RAND_bytes(&c, 1);
217        c = (c % BN_BITS) - BN_BITS2;
218        BN_rand(b, NUM_BITS + c, 0, 0);
219
220        RAND_bytes(&c, 1);
221        c = (c % BN_BITS) - BN_BITS2;
222        BN_rand(m, NUM_BITS + c, 0, 1);
223
224        BN_mod(a, a, m, ctx);
225        BN_mod(b, b, m, ctx);
226
227        ret = BN_mod_exp_mont(r_mont, a, b, m, ctx, NULL);
228        if (ret <= 0) {
229            printf("BN_mod_exp_mont() problems\n");
230            ERR_print_errors(out);
231            EXIT(1);
232        }
233
234        ret = BN_mod_exp_recp(r_recp, a, b, m, ctx);
235        if (ret <= 0) {
236            printf("BN_mod_exp_recp() problems\n");
237            ERR_print_errors(out);
238            EXIT(1);
239        }
240
241        ret = BN_mod_exp_simple(r_simple, a, b, m, ctx);
242        if (ret <= 0) {
243            printf("BN_mod_exp_simple() problems\n");
244            ERR_print_errors(out);
245            EXIT(1);
246        }
247
248        ret = BN_mod_exp_mont_consttime(r_mont_const, a, b, m, ctx, NULL);
249        if (ret <= 0) {
250            printf("BN_mod_exp_mont_consttime() problems\n");
251            ERR_print_errors(out);
252            EXIT(1);
253        }
254
255        if (BN_cmp(r_simple, r_mont) == 0
256            && BN_cmp(r_simple, r_recp) == 0
257            && BN_cmp(r_simple, r_mont_const) == 0) {
258            printf(".");
259            fflush(stdout);
260        } else {
261            if (BN_cmp(r_simple, r_mont) != 0)
262                printf("\nsimple and mont results differ\n");
263            if (BN_cmp(r_simple, r_mont_const) != 0)
264                printf("\nsimple and mont const time results differ\n");
265            if (BN_cmp(r_simple, r_recp) != 0)
266                printf("\nsimple and recp results differ\n");
267
268            printf("a (%3d) = ", BN_num_bits(a));
269            BN_print(out, a);
270            printf("\nb (%3d) = ", BN_num_bits(b));
271            BN_print(out, b);
272            printf("\nm (%3d) = ", BN_num_bits(m));
273            BN_print(out, m);
274            printf("\nsimple   =");
275            BN_print(out, r_simple);
276            printf("\nrecp     =");
277            BN_print(out, r_recp);
278            printf("\nmont     =");
279            BN_print(out, r_mont);
280            printf("\nmont_ct  =");
281            BN_print(out, r_mont_const);
282            printf("\n");
283            EXIT(1);
284        }
285    }
286    BN_free(r_mont);
287    BN_free(r_mont_const);
288    BN_free(r_recp);
289    BN_free(r_simple);
290    BN_free(a);
291    BN_free(b);
292    BN_free(m);
293    BN_CTX_free(ctx);
294    ERR_remove_thread_state(NULL);
295    CRYPTO_mem_leaks(out);
296    BIO_free(out);
297    printf("\n");
298
299    if (test_exp_mod_zero() != 0)
300        goto err;
301
302    printf("done\n");
303
304    EXIT(0);
305 err:
306    ERR_load_crypto_strings();
307    ERR_print_errors(out);
308#ifdef OPENSSL_SYS_NETWARE
309    printf("ERROR\n");
310#endif
311    EXIT(1);
312    return (1);
313}
314