1 /* crypto/rsa/rsa_gen.c */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
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.
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).
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.
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
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)"
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
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.]
60 * NB: these functions have been "upgraded", the deprecated versions (which
61 * are compatibility wrappers using these functions) are in rsa_depr.c. -
67 #include "internal/cryptlib.h"
68 #include <openssl/bn.h>
69 #include <openssl/rsa.h>
71 static int rsa_builtin_keygen(RSA *rsa, int bits, BIGNUM *e_value,
75 * NB: this wrapper would normally be placed in rsa_lib.c and the static
76 * implementation would probably be in rsa_eay.c. Nonetheless, is kept here
77 * so that we don't introduce a new linker dependency. Eg. any application
78 * that wasn't previously linking object code related to key-generation won't
79 * have to now just because key-generation is part of RSA_METHOD.
81 int RSA_generate_key_ex(RSA *rsa, int bits, BIGNUM *e_value, BN_GENCB *cb)
83 if (rsa->meth->rsa_keygen)
84 return rsa->meth->rsa_keygen(rsa, bits, e_value, cb);
85 return rsa_builtin_keygen(rsa, bits, e_value, cb);
88 static int rsa_builtin_keygen(RSA *rsa, int bits, BIGNUM *e_value,
91 BIGNUM *r0 = NULL, *r1 = NULL, *r2 = NULL, *r3 = NULL, *tmp;
92 BIGNUM *local_r0, *local_d, *local_p;
94 int bitsp, bitsq, ok = -1, n = 0;
100 if (!local_r0 || !local_d || !local_p)
107 r0 = BN_CTX_get(ctx);
108 r1 = BN_CTX_get(ctx);
109 r2 = BN_CTX_get(ctx);
110 r3 = BN_CTX_get(ctx);
114 bitsp = (bits + 1) / 2;
115 bitsq = bits - bitsp;
117 /* We need the RSA components non-NULL */
118 if (!rsa->n && ((rsa->n = BN_new()) == NULL))
120 if (!rsa->d && ((rsa->d = BN_secure_new()) == NULL))
122 if (!rsa->e && ((rsa->e = BN_new()) == NULL))
124 if (!rsa->p && ((rsa->p = BN_secure_new()) == NULL))
126 if (!rsa->q && ((rsa->q = BN_secure_new()) == NULL))
128 if (!rsa->dmp1 && ((rsa->dmp1 = BN_secure_new()) == NULL))
130 if (!rsa->dmq1 && ((rsa->dmq1 = BN_secure_new()) == NULL))
132 if (!rsa->iqmp && ((rsa->iqmp = BN_secure_new()) == NULL))
135 BN_copy(rsa->e, e_value);
137 /* generate p and q */
139 if (!BN_generate_prime_ex(rsa->p, bitsp, 0, NULL, NULL, cb))
141 if (!BN_sub(r2, rsa->p, BN_value_one()))
143 if (!BN_gcd(r1, r2, rsa->e, ctx))
147 if (!BN_GENCB_call(cb, 2, n++))
150 if (!BN_GENCB_call(cb, 3, 0))
154 * When generating ridiculously small keys, we can get stuck
155 * continually regenerating the same prime values. Check for this and
156 * bail if it happens 3 times.
158 unsigned int degenerate = 0;
160 if (!BN_generate_prime_ex(rsa->q, bitsq, 0, NULL, NULL, cb))
162 } while ((BN_cmp(rsa->p, rsa->q) == 0) && (++degenerate < 3));
163 if (degenerate == 3) {
164 ok = 0; /* we set our own err */
165 RSAerr(RSA_F_RSA_BUILTIN_KEYGEN, RSA_R_KEY_SIZE_TOO_SMALL);
168 if (!BN_sub(r2, rsa->q, BN_value_one()))
170 if (!BN_gcd(r1, r2, rsa->e, ctx))
174 if (!BN_GENCB_call(cb, 2, n++))
177 if (!BN_GENCB_call(cb, 3, 1))
179 if (BN_cmp(rsa->p, rsa->q) < 0) {
186 if (!BN_mul(rsa->n, rsa->p, rsa->q, ctx))
190 if (!BN_sub(r1, rsa->p, BN_value_one()))
192 if (!BN_sub(r2, rsa->q, BN_value_one()))
194 if (!BN_mul(r0, r1, r2, ctx))
195 goto err; /* (p-1)(q-1) */
196 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
198 BN_with_flags(pr0, r0, BN_FLG_CONSTTIME);
201 if (!BN_mod_inverse(rsa->d, rsa->e, pr0, ctx))
204 /* set up d for correct BN_FLG_CONSTTIME flag */
205 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
207 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
211 /* calculate d mod (p-1) */
212 if (!BN_mod(rsa->dmp1, d, r1, ctx))
215 /* calculate d mod (q-1) */
216 if (!BN_mod(rsa->dmq1, d, r2, ctx))
219 /* calculate inverse of q mod p */
220 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
222 BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME);
225 if (!BN_mod_inverse(rsa->iqmp, rsa->q, p, ctx))
234 RSAerr(RSA_F_RSA_BUILTIN_KEYGEN, ERR_LIB_BN);