1 /* crypto/rsa/rsa_chk.c */
2 /* ====================================================================
3 * Copyright (c) 1999 The OpenSSL Project. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 *
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in
14 * the documentation and/or other materials provided with the
15 * distribution.
16 *
17 * 3. All advertising materials mentioning features or use of this
18 * software must display the following acknowledgment:
19 * "This product includes software developed by the OpenSSL Project
20 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
21 *
22 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
23 * endorse or promote products derived from this software without
24 * prior written permission. For written permission, please contact
25 * openssl-core@OpenSSL.org.
26 *
27 * 5. Products derived from this software may not be called "OpenSSL"
28 * nor may "OpenSSL" appear in their names without prior written
29 * permission of the OpenSSL Project.
30 *
31 * 6. Redistributions of any form whatsoever must retain the following
32 * acknowledgment:
33 * "This product includes software developed by the OpenSSL Project
34 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
35 *
36 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
37 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
38 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
39 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
40 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
41 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
42 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
43 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
44 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
45 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
46 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
47 * OF THE POSSIBILITY OF SUCH DAMAGE.
48 * ====================================================================
49 */
50
51 #include <openssl/bn.h>
52 #include <openssl/err.h>
53 #include <openssl/rsa.h>
54
RSA_check_key(const RSA * key)55 int RSA_check_key(const RSA *key)
56 {
57 BIGNUM *i, *j, *k, *l, *m;
58 BN_CTX *ctx;
59 int ret = 1;
60
61 if (!key->p || !key->q || !key->n || !key->e || !key->d) {
62 RSAerr(RSA_F_RSA_CHECK_KEY, RSA_R_VALUE_MISSING);
63 return 0;
64 }
65
66 i = BN_new();
67 j = BN_new();
68 k = BN_new();
69 l = BN_new();
70 m = BN_new();
71 ctx = BN_CTX_new();
72 if (i == NULL || j == NULL || k == NULL || l == NULL
73 || m == NULL || ctx == NULL) {
74 ret = -1;
75 RSAerr(RSA_F_RSA_CHECK_KEY, ERR_R_MALLOC_FAILURE);
76 goto err;
77 }
78
79 if (BN_is_one(key->e)) {
80 ret = 0;
81 RSAerr(RSA_F_RSA_CHECK_KEY, RSA_R_BAD_E_VALUE);
82 }
83 if (!BN_is_odd(key->e)) {
84 ret = 0;
85 RSAerr(RSA_F_RSA_CHECK_KEY, RSA_R_BAD_E_VALUE);
86 }
87
88 /* p prime? */
89 if (BN_is_prime_ex(key->p, BN_prime_checks, NULL, NULL) != 1) {
90 ret = 0;
91 RSAerr(RSA_F_RSA_CHECK_KEY, RSA_R_P_NOT_PRIME);
92 }
93
94 /* q prime? */
95 if (BN_is_prime_ex(key->q, BN_prime_checks, NULL, NULL) != 1) {
96 ret = 0;
97 RSAerr(RSA_F_RSA_CHECK_KEY, RSA_R_Q_NOT_PRIME);
98 }
99
100 /* n = p*q? */
101 if (!BN_mul(i, key->p, key->q, ctx)) {
102 ret = -1;
103 goto err;
104 }
105 if (BN_cmp(i, key->n) != 0) {
106 ret = 0;
107 RSAerr(RSA_F_RSA_CHECK_KEY, RSA_R_N_DOES_NOT_EQUAL_P_Q);
108 }
109
110 /* d*e = 1 mod lcm(p-1,q-1)? */
111 if (!BN_sub(i, key->p, BN_value_one())) {
112 ret = -1;
113 goto err;
114 }
115 if (!BN_sub(j, key->q, BN_value_one())) {
116 ret = -1;
117 goto err;
118 }
119
120 /* now compute k = lcm(i,j) */
121 if (!BN_mul(l, i, j, ctx)) {
122 ret = -1;
123 goto err;
124 }
125 if (!BN_gcd(m, i, j, ctx)) {
126 ret = -1;
127 goto err;
128 }
129 if (!BN_div(k, NULL, l, m, ctx)) { /* remainder is 0 */
130 ret = -1;
131 goto err;
132 }
133 if (!BN_mod_mul(i, key->d, key->e, k, ctx)) {
134 ret = -1;
135 goto err;
136 }
137
138 if (!BN_is_one(i)) {
139 ret = 0;
140 RSAerr(RSA_F_RSA_CHECK_KEY, RSA_R_D_E_NOT_CONGRUENT_TO_1);
141 }
142
143 if (key->dmp1 != NULL && key->dmq1 != NULL && key->iqmp != NULL) {
144 /* dmp1 = d mod (p-1)? */
145 if (!BN_sub(i, key->p, BN_value_one())) {
146 ret = -1;
147 goto err;
148 }
149 if (!BN_mod(j, key->d, i, ctx)) {
150 ret = -1;
151 goto err;
152 }
153 if (BN_cmp(j, key->dmp1) != 0) {
154 ret = 0;
155 RSAerr(RSA_F_RSA_CHECK_KEY, RSA_R_DMP1_NOT_CONGRUENT_TO_D);
156 }
157
158 /* dmq1 = d mod (q-1)? */
159 if (!BN_sub(i, key->q, BN_value_one())) {
160 ret = -1;
161 goto err;
162 }
163 if (!BN_mod(j, key->d, i, ctx)) {
164 ret = -1;
165 goto err;
166 }
167 if (BN_cmp(j, key->dmq1) != 0) {
168 ret = 0;
169 RSAerr(RSA_F_RSA_CHECK_KEY, RSA_R_DMQ1_NOT_CONGRUENT_TO_D);
170 }
171
172 /* iqmp = q^-1 mod p? */
173 if (!BN_mod_inverse(i, key->q, key->p, ctx)) {
174 ret = -1;
175 goto err;
176 }
177 if (BN_cmp(i, key->iqmp) != 0) {
178 ret = 0;
179 RSAerr(RSA_F_RSA_CHECK_KEY, RSA_R_IQMP_NOT_INVERSE_OF_Q);
180 }
181 }
182
183 err:
184 BN_free(i);
185 BN_free(j);
186 BN_free(k);
187 BN_free(l);
188 BN_free(m);
189 BN_CTX_free(ctx);
190 return ret;
191 }
192