fips_rsa_gen.c revision 296465 
1/* crypto/rsa/rsa_gen.c */
2/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3 * All rights reserved.
4 *
5 * This package is an SSL implementation written
6 * by Eric Young (eay@cryptsoft.com).
7 * The implementation was written so as to conform with Netscapes SSL.
8 *
9 * This library is free for commercial and non-commercial use as long as
10 * the following conditions are aheared to.  The following conditions
11 * apply to all code found in this distribution, be it the RC4, RSA,
12 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
13 * included with this distribution is covered by the same copyright terms
14 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
15 *
16 * Copyright remains Eric Young's, and as such any Copyright notices in
17 * the code are not to be removed.
18 * If this package is used in a product, Eric Young should be given attribution
19 * as the author of the parts of the library used.
20 * This can be in the form of a textual message at program startup or
21 * in documentation (online or textual) provided with the package.
22 *
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
25 * are met:
26 * 1. Redistributions of source code must retain the copyright
27 *    notice, this list of conditions and the following disclaimer.
28 * 2. Redistributions in binary form must reproduce the above copyright
29 *    notice, this list of conditions and the following disclaimer in the
30 *    documentation and/or other materials provided with the distribution.
31 * 3. All advertising materials mentioning features or use of this software
32 *    must display the following acknowledgement:
33 *    "This product includes cryptographic software written by
34 *     Eric Young (eay@cryptsoft.com)"
35 *    The word 'cryptographic' can be left out if the rouines from the library
36 *    being used are not cryptographic related :-).
37 * 4. If you include any Windows specific code (or a derivative thereof) from
38 *    the apps directory (application code) you must include an acknowledgement:
39 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40 *
41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51 * SUCH DAMAGE.
52 *
53 * The licence and distribution terms for any publically available version or
54 * derivative of this code cannot be changed.  i.e. this code cannot simply be
55 * copied and put under another distribution licence
56 * [including the GNU Public Licence.]
57 */
58
59/*
60 * NB: these functions have been "upgraded", the deprecated versions (which
61 * are compatibility wrappers using these functions) are in rsa_depr.c. -
62 * Geoff
63 */
64
65#include <stdio.h>
66#include <time.h>
67#include <string.h>
68#include <openssl/crypto.h>
69#include <openssl/bn.h>
70#include <openssl/rsa.h>
71#include <openssl/err.h>
72#include <openssl/evp.h>
73#include <openssl/fips.h>
74#include "fips_locl.h"
75
76#ifdef OPENSSL_FIPS
77
78static int fips_rsa_pairwise_fail = 0;
79
80void FIPS_corrupt_rsa_keygen(void)
81{
82    fips_rsa_pairwise_fail = 1;
83}
84
85int fips_check_rsa(RSA *rsa)
86{
87    const unsigned char tbs[] = "RSA Pairwise Check Data";
88    unsigned char *ctbuf = NULL, *ptbuf = NULL;
89    int len, ret = 0;
90    EVP_PKEY pk;
91    pk.type = EVP_PKEY_RSA;
92    pk.pkey.rsa = rsa;
93
94    /* Perform pairwise consistency signature test */
95    if (!fips_pkey_signature_test(&pk, tbs, -1,
96                                  NULL, 0, EVP_sha1(),
97                                  EVP_MD_CTX_FLAG_PAD_PKCS1, NULL)
98        || !fips_pkey_signature_test(&pk, tbs, -1, NULL, 0, EVP_sha1(),
99                                     EVP_MD_CTX_FLAG_PAD_X931, NULL)
100        || !fips_pkey_signature_test(&pk, tbs, -1, NULL, 0, EVP_sha1(),
101                                     EVP_MD_CTX_FLAG_PAD_PSS, NULL))
102        goto err;
103    /* Now perform pairwise consistency encrypt/decrypt test */
104    ctbuf = OPENSSL_malloc(RSA_size(rsa));
105    if (!ctbuf)
106        goto err;
107
108    len =
109        RSA_public_encrypt(sizeof(tbs) - 1, tbs, ctbuf, rsa,
110                           RSA_PKCS1_PADDING);
111    if (len <= 0)
112        goto err;
113    /* Check ciphertext doesn't match plaintext */
114    if ((len == (sizeof(tbs) - 1)) && !memcmp(tbs, ctbuf, len))
115        goto err;
116    ptbuf = OPENSSL_malloc(RSA_size(rsa));
117
118    if (!ptbuf)
119        goto err;
120    len = RSA_private_decrypt(len, ctbuf, ptbuf, rsa, RSA_PKCS1_PADDING);
121    if (len != (sizeof(tbs) - 1))
122        goto err;
123    if (memcmp(ptbuf, tbs, len))
124        goto err;
125
126    ret = 1;
127
128    if (!ptbuf)
129        goto err;
130
131 err:
132    if (ret == 0) {
133        fips_set_selftest_fail();
134        FIPSerr(FIPS_F_FIPS_CHECK_RSA, FIPS_R_PAIRWISE_TEST_FAILED);
135    }
136
137    if (ctbuf)
138        OPENSSL_free(ctbuf);
139    if (ptbuf)
140        OPENSSL_free(ptbuf);
141
142    return ret;
143}
144
145static int rsa_builtin_keygen(RSA *rsa, int bits, BIGNUM *e_value,
146                              BN_GENCB *cb);
147
148/*
149 * NB: this wrapper would normally be placed in rsa_lib.c and the static
150 * implementation would probably be in rsa_eay.c. Nonetheless, is kept here
151 * so that we don't introduce a new linker dependency. Eg. any application
152 * that wasn't previously linking object code related to key-generation won't
153 * have to now just because key-generation is part of RSA_METHOD.
154 */
155int RSA_generate_key_ex(RSA *rsa, int bits, BIGNUM *e_value, BN_GENCB *cb)
156{
157    if (rsa->meth->rsa_keygen)
158        return rsa->meth->rsa_keygen(rsa, bits, e_value, cb);
159    return rsa_builtin_keygen(rsa, bits, e_value, cb);
160}
161
162static int rsa_builtin_keygen(RSA *rsa, int bits, BIGNUM *e_value,
163                              BN_GENCB *cb)
164{
165    BIGNUM *r0 = NULL, *r1 = NULL, *r2 = NULL, *r3 = NULL, *tmp;
166    BIGNUM local_r0, local_d, local_p;
167    BIGNUM *pr0, *d, *p;
168    int bitsp, bitsq, ok = -1, n = 0;
169    BN_CTX *ctx = NULL;
170
171    if (FIPS_selftest_failed()) {
172        FIPSerr(FIPS_F_RSA_BUILTIN_KEYGEN, FIPS_R_FIPS_SELFTEST_FAILED);
173        return 0;
174    }
175
176    if (FIPS_mode() && (bits < OPENSSL_RSA_FIPS_MIN_MODULUS_BITS)) {
177        FIPSerr(FIPS_F_RSA_BUILTIN_KEYGEN, FIPS_R_KEY_TOO_SHORT);
178        return 0;
179    }
180
181    ctx = BN_CTX_new();
182    if (ctx == NULL)
183        goto err;
184    BN_CTX_start(ctx);
185    r0 = BN_CTX_get(ctx);
186    r1 = BN_CTX_get(ctx);
187    r2 = BN_CTX_get(ctx);
188    r3 = BN_CTX_get(ctx);
189    if (r3 == NULL)
190        goto err;
191
192    bitsp = (bits + 1) / 2;
193    bitsq = bits - bitsp;
194
195    /* We need the RSA components non-NULL */
196    if (!rsa->n && ((rsa->n = BN_new()) == NULL))
197        goto err;
198    if (!rsa->d && ((rsa->d = BN_new()) == NULL))
199        goto err;
200    if (!rsa->e && ((rsa->e = BN_new()) == NULL))
201        goto err;
202    if (!rsa->p && ((rsa->p = BN_new()) == NULL))
203        goto err;
204    if (!rsa->q && ((rsa->q = BN_new()) == NULL))
205        goto err;
206    if (!rsa->dmp1 && ((rsa->dmp1 = BN_new()) == NULL))
207        goto err;
208    if (!rsa->dmq1 && ((rsa->dmq1 = BN_new()) == NULL))
209        goto err;
210    if (!rsa->iqmp && ((rsa->iqmp = BN_new()) == NULL))
211        goto err;
212
213    BN_copy(rsa->e, e_value);
214
215    /* generate p and q */
216    for (;;) {
217        if (!BN_generate_prime_ex(rsa->p, bitsp, 0, NULL, NULL, cb))
218            goto err;
219        if (!BN_sub(r2, rsa->p, BN_value_one()))
220            goto err;
221        if (!BN_gcd(r1, r2, rsa->e, ctx))
222            goto err;
223        if (BN_is_one(r1))
224            break;
225        if (!BN_GENCB_call(cb, 2, n++))
226            goto err;
227    }
228    if (!BN_GENCB_call(cb, 3, 0))
229        goto err;
230    for (;;) {
231        /*
232         * When generating ridiculously small keys, we can get stuck
233         * continually regenerating the same prime values. Check for this and
234         * bail if it happens 3 times.
235         */
236        unsigned int degenerate = 0;
237        do {
238            if (!BN_generate_prime_ex(rsa->q, bitsq, 0, NULL, NULL, cb))
239                goto err;
240        } while ((BN_cmp(rsa->p, rsa->q) == 0) && (++degenerate < 3));
241        if (degenerate == 3) {
242            ok = 0;             /* we set our own err */
243            RSAerr(RSA_F_RSA_BUILTIN_KEYGEN, RSA_R_KEY_SIZE_TOO_SMALL);
244            goto err;
245        }
246        if (!BN_sub(r2, rsa->q, BN_value_one()))
247            goto err;
248        if (!BN_gcd(r1, r2, rsa->e, ctx))
249            goto err;
250        if (BN_is_one(r1))
251            break;
252        if (!BN_GENCB_call(cb, 2, n++))
253            goto err;
254    }
255    if (!BN_GENCB_call(cb, 3, 1))
256        goto err;
257    if (BN_cmp(rsa->p, rsa->q) < 0) {
258        tmp = rsa->p;
259        rsa->p = rsa->q;
260        rsa->q = tmp;
261    }
262
263    /* calculate n */
264    if (!BN_mul(rsa->n, rsa->p, rsa->q, ctx))
265        goto err;
266
267    /* calculate d */
268    if (!BN_sub(r1, rsa->p, BN_value_one()))
269        goto err;               /* p-1 */
270    if (!BN_sub(r2, rsa->q, BN_value_one()))
271        goto err;               /* q-1 */
272    if (!BN_mul(r0, r1, r2, ctx))
273        goto err;               /* (p-1)(q-1) */
274    if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
275        pr0 = &local_r0;
276        BN_with_flags(pr0, r0, BN_FLG_CONSTTIME);
277    } else
278        pr0 = r0;
279    if (!BN_mod_inverse(rsa->d, rsa->e, pr0, ctx))
280        goto err;               /* d */
281
282    /* set up d for correct BN_FLG_CONSTTIME flag */
283    if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
284        d = &local_d;
285        BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
286    } else
287        d = rsa->d;
288
289    /* calculate d mod (p-1) */
290    if (!BN_mod(rsa->dmp1, d, r1, ctx))
291        goto err;
292
293    /* calculate d mod (q-1) */
294    if (!BN_mod(rsa->dmq1, d, r2, ctx))
295        goto err;
296
297    /* calculate inverse of q mod p */
298    if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
299        p = &local_p;
300        BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME);
301    } else
302        p = rsa->p;
303    if (!BN_mod_inverse(rsa->iqmp, rsa->q, p, ctx))
304        goto err;
305
306    if (fips_rsa_pairwise_fail)
307        BN_add_word(rsa->n, 1);
308
309    if (!fips_check_rsa(rsa))
310        goto err;
311
312    ok = 1;
313 err:
314    if (ok == -1) {
315        RSAerr(RSA_F_RSA_BUILTIN_KEYGEN, ERR_LIB_BN);
316        ok = 0;
317    }
318    if (ctx != NULL) {
319        BN_CTX_end(ctx);
320        BN_CTX_free(ctx);
321    }
322
323    return ok;
324}
325
326#endif
327