2 * Copyright 1995-2023 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
14 #include "internal/nelem.h"
16 #include <openssl/bio.h>
17 #include <openssl/bn.h>
18 #include <openssl/rand.h>
19 #include <openssl/err.h>
23 #define NUM_BITS (BN_BITS2 * 4)
25 #define BN_print_var(v) test_output_bignum(#v, v)
28 * Test that r == 0 in test_exp_mod_zero(). Returns one on success,
29 * returns zero and prints debug output otherwise.
31 static int a_is_zero_mod_one(const char *method, const BIGNUM *r,
35 TEST_error("%s failed: a ** 0 mod 1 = r (should be 0)", method);
44 * test_mod_exp_zero tests that x**0 mod 1 == 0. It returns zero on success.
46 static int test_mod_exp_zero(void)
48 BIGNUM *a = NULL, *p = NULL, *m = NULL;
50 BN_ULONG one_word = 1;
51 BN_CTX *ctx = BN_CTX_new();
52 int ret = 0, failed = 0;
53 BN_MONT_CTX *mont = NULL;
55 if (!TEST_ptr(m = BN_new())
56 || !TEST_ptr(a = BN_new())
57 || !TEST_ptr(p = BN_new())
58 || !TEST_ptr(r = BN_new()))
65 if (!TEST_true(BN_rand(a, 1024, BN_RAND_TOP_ONE, BN_RAND_BOTTOM_ANY)))
68 if (!TEST_true(BN_mod_exp(r, a, p, m, ctx)))
71 if (!TEST_true(a_is_zero_mod_one("BN_mod_exp", r, a)))
74 if (!TEST_true(BN_mod_exp_recp(r, a, p, m, ctx)))
77 if (!TEST_true(a_is_zero_mod_one("BN_mod_exp_recp", r, a)))
80 if (!TEST_true(BN_mod_exp_simple(r, a, p, m, ctx)))
83 if (!TEST_true(a_is_zero_mod_one("BN_mod_exp_simple", r, a)))
86 if (!TEST_true(BN_mod_exp_mont(r, a, p, m, ctx, NULL)))
89 if (!TEST_true(a_is_zero_mod_one("BN_mod_exp_mont", r, a)))
92 if (!TEST_true(BN_mod_exp_mont_consttime(r, a, p, m, ctx, NULL)))
95 if (!TEST_true(a_is_zero_mod_one("BN_mod_exp_mont_consttime", r, a)))
98 if (!TEST_ptr(mont = BN_MONT_CTX_new()))
102 /* mont is not set but passed in */
103 if (!TEST_false(BN_mod_exp_mont_consttime(r, p, a, m, ctx, mont)))
105 if (!TEST_false(BN_mod_exp_mont(r, p, a, m, ctx, mont)))
109 if (!TEST_true(BN_MONT_CTX_set(mont, m, ctx)))
112 /* we compute 0 ** a mod 1 here, to execute code that uses mont */
113 if (!TEST_true(BN_mod_exp_mont_consttime(r, p, a, m, ctx, mont)))
116 if (!TEST_true(a_is_zero_mod_one("BN_mod_exp_mont_consttime", r, a)))
119 if (!TEST_true(BN_mod_exp_mont(r, p, a, m, ctx, mont)))
122 if (!TEST_true(a_is_zero_mod_one("BN_mod_exp_mont", r, a)))
126 * A different codepath exists for single word multiplication
127 * in non-constant-time only.
129 if (!TEST_true(BN_mod_exp_mont_word(r, one_word, p, m, ctx, NULL)))
132 if (!TEST_BN_eq_zero(r)) {
133 TEST_error("BN_mod_exp_mont_word failed: "
134 "1 ** 0 mod 1 = r (should be 0)");
145 BN_MONT_CTX_free(mont);
151 static int test_mod_exp(int round)
156 BIGNUM *r_mont = NULL;
157 BIGNUM *r_mont_const = NULL;
158 BIGNUM *r_recp = NULL;
159 BIGNUM *r_simple = NULL;
164 if (!TEST_ptr(ctx = BN_CTX_new()))
167 if (!TEST_ptr(r_mont = BN_new())
168 || !TEST_ptr(r_mont_const = BN_new())
169 || !TEST_ptr(r_recp = BN_new())
170 || !TEST_ptr(r_simple = BN_new())
171 || !TEST_ptr(a = BN_new())
172 || !TEST_ptr(b = BN_new())
173 || !TEST_ptr(m = BN_new()))
176 if (!TEST_int_gt(RAND_bytes(&c, 1), 0))
178 c = (c % BN_BITS) - BN_BITS2;
179 if (!TEST_true(BN_rand(a, NUM_BITS + c, BN_RAND_TOP_ONE,
180 BN_RAND_BOTTOM_ANY)))
183 if (!TEST_int_gt(RAND_bytes(&c, 1), 0))
185 c = (c % BN_BITS) - BN_BITS2;
186 if (!TEST_true(BN_rand(b, NUM_BITS + c, BN_RAND_TOP_ONE,
187 BN_RAND_BOTTOM_ANY)))
190 if (!TEST_int_gt(RAND_bytes(&c, 1), 0))
192 c = (c % BN_BITS) - BN_BITS2;
193 if (!TEST_true(BN_rand(m, NUM_BITS + c, BN_RAND_TOP_ONE,
194 BN_RAND_BOTTOM_ODD)))
197 if (!TEST_true(BN_mod(a, a, m, ctx))
198 || !TEST_true(BN_mod(b, b, m, ctx))
199 || !TEST_true(BN_mod_exp_mont(r_mont, a, b, m, ctx, NULL))
200 || !TEST_true(BN_mod_exp_recp(r_recp, a, b, m, ctx))
201 || !TEST_true(BN_mod_exp_simple(r_simple, a, b, m, ctx))
202 || !TEST_true(BN_mod_exp_mont_consttime(r_mont_const, a, b, m, ctx, NULL)))
205 if (!TEST_BN_eq(r_simple, r_mont)
206 || !TEST_BN_eq(r_simple, r_recp)
207 || !TEST_BN_eq(r_simple, r_mont_const)) {
208 if (BN_cmp(r_simple, r_mont) != 0)
209 TEST_info("simple and mont results differ");
210 if (BN_cmp(r_simple, r_mont_const) != 0)
211 TEST_info("simple and mont const time results differ");
212 if (BN_cmp(r_simple, r_recp) != 0)
213 TEST_info("simple and recp results differ");
218 BN_print_var(r_simple);
219 BN_print_var(r_recp);
220 BN_print_var(r_mont);
221 BN_print_var(r_mont_const);
228 BN_free(r_mont_const);
239 static int test_mod_exp_x2(int idx)
243 BIGNUM *r_mont_const_x2_1 = NULL;
244 BIGNUM *r_mont_const_x2_2 = NULL;
245 BIGNUM *r_simple1 = NULL;
246 BIGNUM *r_simple2 = NULL;
262 if (!TEST_ptr(ctx = BN_CTX_new()))
265 if (!TEST_ptr(r_mont_const_x2_1 = BN_new())
266 || !TEST_ptr(r_mont_const_x2_2 = BN_new())
267 || !TEST_ptr(r_simple1 = BN_new())
268 || !TEST_ptr(r_simple2 = BN_new())
269 || !TEST_ptr(a1 = BN_new())
270 || !TEST_ptr(b1 = BN_new())
271 || !TEST_ptr(m1 = BN_new())
272 || !TEST_ptr(a2 = BN_new())
273 || !TEST_ptr(b2 = BN_new())
274 || !TEST_ptr(m2 = BN_new()))
277 BN_rand(a1, factor_size, BN_RAND_TOP_ONE, BN_RAND_BOTTOM_ANY);
278 BN_rand(b1, factor_size, BN_RAND_TOP_ONE, BN_RAND_BOTTOM_ANY);
279 BN_rand(m1, factor_size, BN_RAND_TOP_ONE, BN_RAND_BOTTOM_ODD);
280 BN_rand(a2, factor_size, BN_RAND_TOP_ONE, BN_RAND_BOTTOM_ANY);
281 BN_rand(b2, factor_size, BN_RAND_TOP_ONE, BN_RAND_BOTTOM_ANY);
282 BN_rand(m2, factor_size, BN_RAND_TOP_ONE, BN_RAND_BOTTOM_ODD);
284 if (!TEST_true(BN_mod(a1, a1, m1, ctx))
285 || !TEST_true(BN_mod(b1, b1, m1, ctx))
286 || !TEST_true(BN_mod(a2, a2, m2, ctx))
287 || !TEST_true(BN_mod(b2, b2, m2, ctx))
288 || !TEST_true(BN_mod_exp_simple(r_simple1, a1, b1, m1, ctx))
289 || !TEST_true(BN_mod_exp_simple(r_simple2, a2, b2, m2, ctx))
290 || !TEST_true(BN_mod_exp_mont_consttime_x2(r_mont_const_x2_1, a1, b1, m1, NULL,
291 r_mont_const_x2_2, a2, b2, m2, NULL,
295 if (!TEST_BN_eq(r_simple1, r_mont_const_x2_1)
296 || !TEST_BN_eq(r_simple2, r_mont_const_x2_2)) {
297 if (BN_cmp(r_simple1, r_mont_const_x2_1) != 0)
298 TEST_info("simple and mont const time x2 (#1) results differ");
299 if (BN_cmp(r_simple2, r_mont_const_x2_2) != 0)
300 TEST_info("simple and mont const time x2 (#2) results differ");
308 BN_print_var(r_simple1);
309 BN_print_var(r_simple2);
310 BN_print_var(r_mont_const_x2_1);
311 BN_print_var(r_mont_const_x2_2);
317 BN_free(r_mont_const_x2_1);
318 BN_free(r_mont_const_x2_2);
332 int setup_tests(void)
334 ADD_TEST(test_mod_exp_zero);
335 ADD_ALL_TESTS(test_mod_exp, 200);
336 ADD_ALL_TESTS(test_mod_exp_x2, 300);