rsa_chk.c revision 306195 
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 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