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git.ipfire.org Git - thirdparty/openssl.git/blob - crypto/rsa/rsa_gen.c
1 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
4 * This package is an SSL implementation written
5 * by Eric Young (eay@cryptsoft.com).
6 * The implementation was written so as to conform with Netscapes SSL.
8 * This library is free for commercial and non-commercial use as long as
9 * the following conditions are aheared to. The following conditions
10 * apply to all code found in this distribution, be it the RC4, RSA,
11 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
12 * included with this distribution is covered by the same copyright terms
13 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
15 * Copyright remains Eric Young's, and as such any Copyright notices in
16 * the code are not to be removed.
17 * If this package is used in a product, Eric Young should be given attribution
18 * as the author of the parts of the library used.
19 * This can be in the form of a textual message at program startup or
20 * in documentation (online or textual) provided with the package.
22 * Redistribution and use in source and binary forms, with or without
23 * modification, are permitted provided that the following conditions
25 * 1. Redistributions of source code must retain the copyright
26 * notice, this list of conditions and the following disclaimer.
27 * 2. Redistributions in binary form must reproduce the above copyright
28 * notice, this list of conditions and the following disclaimer in the
29 * documentation and/or other materials provided with the distribution.
30 * 3. All advertising materials mentioning features or use of this software
31 * must display the following acknowledgement:
32 * "This product includes cryptographic software written by
33 * Eric Young (eay@cryptsoft.com)"
34 * The word 'cryptographic' can be left out if the rouines from the library
35 * being used are not cryptographic related :-).
36 * 4. If you include any Windows specific code (or a derivative thereof) from
37 * the apps directory (application code) you must include an acknowledgement:
38 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
41 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
44 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
52 * The licence and distribution terms for any publically available version or
53 * derivative of this code cannot be changed. i.e. this code cannot simply be
54 * copied and put under another distribution licence
55 * [including the GNU Public Licence.]
59 * NB: these functions have been "upgraded", the deprecated versions (which
60 * are compatibility wrappers using these functions) are in rsa_depr.c. -
66 #include "internal/cryptlib.h"
67 #include <openssl/bn.h>
68 #include <openssl/rsa.h>
70 static int rsa_builtin_keygen(RSA
*rsa
, int bits
, BIGNUM
*e_value
,
74 * NB: this wrapper would normally be placed in rsa_lib.c and the static
75 * implementation would probably be in rsa_eay.c. Nonetheless, is kept here
76 * so that we don't introduce a new linker dependency. Eg. any application
77 * that wasn't previously linking object code related to key-generation won't
78 * have to now just because key-generation is part of RSA_METHOD.
80 int RSA_generate_key_ex(RSA
*rsa
, int bits
, BIGNUM
*e_value
, BN_GENCB
*cb
)
82 if (rsa
->meth
->rsa_keygen
)
83 return rsa
->meth
->rsa_keygen(rsa
, bits
, e_value
, cb
);
84 return rsa_builtin_keygen(rsa
, bits
, e_value
, cb
);
87 static int rsa_builtin_keygen(RSA
*rsa
, int bits
, BIGNUM
*e_value
,
90 BIGNUM
*r0
= NULL
, *r1
= NULL
, *r2
= NULL
, *r3
= NULL
, *tmp
;
91 int bitsp
, bitsq
, ok
= -1, n
= 0;
100 r2
= BN_CTX_get(ctx
);
101 r3
= BN_CTX_get(ctx
);
105 bitsp
= (bits
+ 1) / 2;
106 bitsq
= bits
- bitsp
;
108 /* We need the RSA components non-NULL */
109 if (!rsa
->n
&& ((rsa
->n
= BN_new()) == NULL
))
111 if (!rsa
->d
&& ((rsa
->d
= BN_secure_new()) == NULL
))
113 if (!rsa
->e
&& ((rsa
->e
= BN_new()) == NULL
))
115 if (!rsa
->p
&& ((rsa
->p
= BN_secure_new()) == NULL
))
117 if (!rsa
->q
&& ((rsa
->q
= BN_secure_new()) == NULL
))
119 if (!rsa
->dmp1
&& ((rsa
->dmp1
= BN_secure_new()) == NULL
))
121 if (!rsa
->dmq1
&& ((rsa
->dmq1
= BN_secure_new()) == NULL
))
123 if (!rsa
->iqmp
&& ((rsa
->iqmp
= BN_secure_new()) == NULL
))
126 BN_copy(rsa
->e
, e_value
);
128 /* generate p and q */
130 if (!BN_generate_prime_ex(rsa
->p
, bitsp
, 0, NULL
, NULL
, cb
))
132 if (!BN_sub(r2
, rsa
->p
, BN_value_one()))
134 if (!BN_gcd(r1
, r2
, rsa
->e
, ctx
))
138 if (!BN_GENCB_call(cb
, 2, n
++))
141 if (!BN_GENCB_call(cb
, 3, 0))
145 * When generating ridiculously small keys, we can get stuck
146 * continually regenerating the same prime values. Check for this and
147 * bail if it happens 3 times.
149 unsigned int degenerate
= 0;
151 if (!BN_generate_prime_ex(rsa
->q
, bitsq
, 0, NULL
, NULL
, cb
))
153 } while ((BN_cmp(rsa
->p
, rsa
->q
) == 0) && (++degenerate
< 3));
154 if (degenerate
== 3) {
155 ok
= 0; /* we set our own err */
156 RSAerr(RSA_F_RSA_BUILTIN_KEYGEN
, RSA_R_KEY_SIZE_TOO_SMALL
);
159 if (!BN_sub(r2
, rsa
->q
, BN_value_one()))
161 if (!BN_gcd(r1
, r2
, rsa
->e
, ctx
))
165 if (!BN_GENCB_call(cb
, 2, n
++))
168 if (!BN_GENCB_call(cb
, 3, 1))
170 if (BN_cmp(rsa
->p
, rsa
->q
) < 0) {
177 if (!BN_mul(rsa
->n
, rsa
->p
, rsa
->q
, ctx
))
181 if (!BN_sub(r1
, rsa
->p
, BN_value_one()))
183 if (!BN_sub(r2
, rsa
->q
, BN_value_one()))
185 if (!BN_mul(r0
, r1
, r2
, ctx
))
186 goto err
; /* (p-1)(q-1) */
188 BIGNUM
*local_r0
= NULL
, *pr0
;
189 if (!(rsa
->flags
& RSA_FLAG_NO_CONSTTIME
)) {
190 pr0
= local_r0
= BN_new();
191 if (local_r0
== NULL
)
193 BN_with_flags(pr0
, r0
, BN_FLG_CONSTTIME
);
197 if (!BN_mod_inverse(rsa
->d
, rsa
->e
, pr0
, ctx
)) {
201 /* We MUST free local_r0 before any further use of r0 */
206 BIGNUM
*local_d
= NULL
, *d
;
207 /* set up d for correct BN_FLG_CONSTTIME flag */
208 if (!(rsa
->flags
& RSA_FLAG_NO_CONSTTIME
)) {
209 d
= local_d
= BN_new();
212 BN_with_flags(d
, rsa
->d
, BN_FLG_CONSTTIME
);
217 if ( /* calculate d mod (p-1) */
218 !BN_mod(rsa
->dmp1
, d
, r1
, ctx
)
219 /* calculate d mod (q-1) */
220 || !BN_mod(rsa
->dmq1
, d
, r2
, ctx
)) {
224 /* We MUST free local_d before any further use of rsa->d */
229 BIGNUM
*local_p
= NULL
, *p
;
231 /* calculate inverse of q mod p */
232 if (!(rsa
->flags
& RSA_FLAG_NO_CONSTTIME
)) {
233 p
= local_p
= BN_new();
236 BN_with_flags(p
, rsa
->p
, BN_FLG_CONSTTIME
);
240 if (!BN_mod_inverse(rsa
->iqmp
, rsa
->q
, p
, ctx
)) {
244 /* We MUST free local_p before any further use of rsa->p */
251 RSAerr(RSA_F_RSA_BUILTIN_KEYGEN
, ERR_LIB_BN
);