rsa_chk.c revision 296465 
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
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    i = BN_new();
63    j = BN_new();
64    k = BN_new();
65    l = BN_new();
66    m = BN_new();
67    ctx = BN_CTX_new();
68    if (i == NULL || j == NULL || k == NULL || l == NULL ||
69        m == NULL || ctx == NULL) {
70        ret = -1;
71        RSAerr(RSA_F_RSA_CHECK_KEY, ERR_R_MALLOC_FAILURE);
72        goto err;
73    }
74
75    /* p prime? */
76    r = BN_is_prime_ex(key->p, BN_prime_checks, NULL, NULL);
77    if (r != 1) {
78        ret = r;
79        if (r != 0)
80            goto err;
81        RSAerr(RSA_F_RSA_CHECK_KEY, RSA_R_P_NOT_PRIME);
82    }
83
84    /* q prime? */
85    r = BN_is_prime_ex(key->q, BN_prime_checks, NULL, NULL);
86    if (r != 1) {
87        ret = r;
88        if (r != 0)
89            goto err;
90        RSAerr(RSA_F_RSA_CHECK_KEY, RSA_R_Q_NOT_PRIME);
91    }
92
93    /* n = p*q? */
94    r = BN_mul(i, key->p, key->q, ctx);
95    if (!r) {
96        ret = -1;
97        goto err;
98    }
99
100    if (BN_cmp(i, key->n) != 0) {
101        ret = 0;
102        RSAerr(RSA_F_RSA_CHECK_KEY, RSA_R_N_DOES_NOT_EQUAL_P_Q);
103    }
104
105    /* d*e = 1  mod lcm(p-1,q-1)? */
106
107    r = BN_sub(i, key->p, BN_value_one());
108    if (!r) {
109        ret = -1;
110        goto err;
111    }
112    r = BN_sub(j, key->q, BN_value_one());
113    if (!r) {
114        ret = -1;
115        goto err;
116    }
117
118    /* now compute k = lcm(i,j) */
119    r = BN_mul(l, i, j, ctx);
120    if (!r) {
121        ret = -1;
122        goto err;
123    }
124    r = BN_gcd(m, i, j, ctx);
125    if (!r) {
126        ret = -1;
127        goto err;
128    }
129    r = BN_div(k, NULL, l, m, ctx); /* remainder is 0 */
130    if (!r) {
131        ret = -1;
132        goto err;
133    }
134
135    r = BN_mod_mul(i, key->d, key->e, k, ctx);
136    if (!r) {
137        ret = -1;
138        goto err;
139    }
140
141    if (!BN_is_one(i)) {
142        ret = 0;
143        RSAerr(RSA_F_RSA_CHECK_KEY, RSA_R_D_E_NOT_CONGRUENT_TO_1);
144    }
145
146    if (key->dmp1 != NULL && key->dmq1 != NULL && key->iqmp != NULL) {
147        /* dmp1 = d mod (p-1)? */
148        r = BN_sub(i, key->p, BN_value_one());
149        if (!r) {
150            ret = -1;
151            goto err;
152        }
153
154        r = BN_mod(j, key->d, i, ctx);
155        if (!r) {
156            ret = -1;
157            goto err;
158        }
159
160        if (BN_cmp(j, key->dmp1) != 0) {
161            ret = 0;
162            RSAerr(RSA_F_RSA_CHECK_KEY, RSA_R_DMP1_NOT_CONGRUENT_TO_D);
163        }
164
165        /* dmq1 = d mod (q-1)? */
166        r = BN_sub(i, key->q, BN_value_one());
167        if (!r) {
168            ret = -1;
169            goto err;
170        }
171
172        r = BN_mod(j, key->d, i, ctx);
173        if (!r) {
174            ret = -1;
175            goto err;
176        }
177
178        if (BN_cmp(j, key->dmq1) != 0) {
179            ret = 0;
180            RSAerr(RSA_F_RSA_CHECK_KEY, RSA_R_DMQ1_NOT_CONGRUENT_TO_D);
181        }
182
183        /* iqmp = q^-1 mod p? */
184        if (!BN_mod_inverse(i, key->q, key->p, ctx)) {
185            ret = -1;
186            goto err;
187        }
188
189        if (BN_cmp(i, key->iqmp) != 0) {
190            ret = 0;
191            RSAerr(RSA_F_RSA_CHECK_KEY, RSA_R_IQMP_NOT_INVERSE_OF_Q);
192        }
193    }
194
195 err:
196    if (i != NULL)
197        BN_free(i);
198    if (j != NULL)
199        BN_free(j);
200    if (k != NULL)
201        BN_free(k);
202    if (l != NULL)
203        BN_free(l);
204    if (m != NULL)
205        BN_free(m);
206    if (ctx != NULL)
207        BN_CTX_free(ctx);
208    return (ret);
209}
210