rsa_chk.c revision 295016 
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
55int 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