1 /* crypto/rsa/rsa_chk.c -*- Mode: C; c-file-style: "eay" -*- */
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 r;
60 int ret = 1;
61
62 if (!key->p || !key->q || !key->n || !key->e || !key->d) {
63 RSAerr(RSA_F_RSA_CHECK_KEY, RSA_R_VALUE_MISSING);
64 return 0;
65 }
66
67 i = BN_new();
68 j = BN_new();
69 k = BN_new();
70 l = BN_new();
71 m = BN_new();
72 ctx = BN_CTX_new();
73 if (i == NULL || j == NULL || k == NULL || l == NULL ||
74 m == NULL || ctx == NULL) {
75 ret = -1;
76 RSAerr(RSA_F_RSA_CHECK_KEY, ERR_R_MALLOC_FAILURE);
77 goto err;
78 }
79
80 /* p prime? */
81 r = BN_is_prime_ex(key->p, BN_prime_checks, NULL, NULL);
82 if (r != 1) {
83 ret = r;
84 if (r != 0)
85 goto err;
86 RSAerr(RSA_F_RSA_CHECK_KEY, RSA_R_P_NOT_PRIME);
87 }
88
89 /* q prime? */
90 r = BN_is_prime_ex(key->q, BN_prime_checks, NULL, NULL);
91 if (r != 1) {
92 ret = r;
93 if (r != 0)
94 goto err;
95 RSAerr(RSA_F_RSA_CHECK_KEY, RSA_R_Q_NOT_PRIME);
96 }
97
98 /* n = p*q? */
99 r = BN_mul(i, key->p, key->q, ctx);
100 if (!r) {
101 ret = -1;
102 goto err;
103 }
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
112 r = BN_sub(i, key->p, BN_value_one());
113 if (!r) {
114 ret = -1;
115 goto err;
116 }
117 r = BN_sub(j, key->q, BN_value_one());
118 if (!r) {
119 ret = -1;
120 goto err;
121 }
122
123 /* now compute k = lcm(i,j) */
124 r = BN_mul(l, i, j, ctx);
125 if (!r) {
126 ret = -1;
127 goto err;
128 }
129 r = BN_gcd(m, i, j, ctx);
130 if (!r) {
131 ret = -1;
132 goto err;
133 }
134 r = BN_div(k, NULL, l, m, ctx); /* remainder is 0 */
135 if (!r) {
136 ret = -1;
137 goto err;
138 }
139
140 r = BN_mod_mul(i, key->d, key->e, k, ctx);
141 if (!r) {
142 ret = -1;
143 goto err;
144 }
145
146 if (!BN_is_one(i)) {
147 ret = 0;
148 RSAerr(RSA_F_RSA_CHECK_KEY, RSA_R_D_E_NOT_CONGRUENT_TO_1);
149 }
150
151 if (key->dmp1 != NULL && key->dmq1 != NULL && key->iqmp != NULL) {
152 /* dmp1 = d mod (p-1)? */
153 r = BN_sub(i, key->p, BN_value_one());
154 if (!r) {
155 ret = -1;
156 goto err;
157 }
158
159 r = BN_mod(j, key->d, i, ctx);
160 if (!r) {
161 ret = -1;
162 goto err;
163 }
164
165 if (BN_cmp(j, key->dmp1) != 0) {
166 ret = 0;
167 RSAerr(RSA_F_RSA_CHECK_KEY, RSA_R_DMP1_NOT_CONGRUENT_TO_D);
168 }
169
170 /* dmq1 = d mod (q-1)? */
171 r = BN_sub(i, key->q, BN_value_one());
172 if (!r) {
173 ret = -1;
174 goto err;
175 }
176
177 r = BN_mod(j, key->d, i, ctx);
178 if (!r) {
179 ret = -1;
180 goto err;
181 }
182
183 if (BN_cmp(j, key->dmq1) != 0) {
184 ret = 0;
185 RSAerr(RSA_F_RSA_CHECK_KEY, RSA_R_DMQ1_NOT_CONGRUENT_TO_D);
186 }
187
188 /* iqmp = q^-1 mod p? */
189 if (!BN_mod_inverse(i, key->q, key->p, ctx)) {
190 ret = -1;
191 goto err;
192 }
193
194 if (BN_cmp(i, key->iqmp) != 0) {
195 ret = 0;
196 RSAerr(RSA_F_RSA_CHECK_KEY, RSA_R_IQMP_NOT_INVERSE_OF_Q);
197 }
198 }
199
200 err:
201 if (i != NULL)
202 BN_free(i);
203 if (j != NULL)
204 BN_free(j);
205 if (k != NULL)
206 BN_free(k);
207 if (l != NULL)
208 BN_free(l);
209 if (m != NULL)
210 BN_free(m);
211 if (ctx != NULL)
212 BN_CTX_free(ctx);
213 return (ret);
214 }
215