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. -
68 #include <openssl/bn.h>
69 #include <openssl/rsa.h>
73 static int rsa_builtin_keygen(RSA *rsa, int bits, BIGNUM *e_value,
77 * NB: this wrapper would normally be placed in rsa_lib.c and the static
78 * implementation would probably be in rsa_eay.c. Nonetheless, is kept here
79 * so that we don't introduce a new linker dependency. Eg. any application
80 * that wasn't previously linking object code related to key-generation won't
81 * have to now just because key-generation is part of RSA_METHOD.
83 int RSA_generate_key_ex(RSA *rsa, int bits, BIGNUM *e_value, BN_GENCB *cb)
85 if (rsa->meth->rsa_keygen)
86 return rsa->meth->rsa_keygen(rsa, bits, e_value, cb);
87 return rsa_builtin_keygen(rsa, bits, e_value, cb);
90 static int rsa_builtin_keygen(RSA *rsa, int bits, BIGNUM *e_value,
93 BIGNUM *r0 = NULL, *r1 = NULL, *r2 = NULL, *r3 = NULL, *tmp;
94 BIGNUM local_r0, local_d, local_p;
96 int bitsp, bitsq, ok = -1, n = 0;
103 r0 = BN_CTX_get(ctx);
104 r1 = BN_CTX_get(ctx);
105 r2 = BN_CTX_get(ctx);
106 r3 = BN_CTX_get(ctx);
110 bitsp = (bits + 1) / 2;
111 bitsq = bits - bitsp;
113 /* We need the RSA components non-NULL */
114 if (!rsa->n && ((rsa->n = BN_new()) == NULL))
116 if (!rsa->d && ((rsa->d = BN_new()) == NULL))
118 if (!rsa->e && ((rsa->e = BN_new()) == NULL))
120 if (!rsa->p && ((rsa->p = BN_new()) == NULL))
122 if (!rsa->q && ((rsa->q = BN_new()) == NULL))
124 if (!rsa->dmp1 && ((rsa->dmp1 = BN_new()) == NULL))
126 if (!rsa->dmq1 && ((rsa->dmq1 = BN_new()) == NULL))
128 if (!rsa->iqmp && ((rsa->iqmp = BN_new()) == NULL))
131 BN_copy(rsa->e, e_value);
133 /* generate p and q */
135 if (!BN_generate_prime_ex(rsa->p, bitsp, 0, NULL, NULL, cb))
137 if (!BN_sub(r2, rsa->p, BN_value_one()))
139 if (!BN_gcd(r1, r2, rsa->e, ctx))
143 if (!BN_GENCB_call(cb, 2, n++))
146 if (!BN_GENCB_call(cb, 3, 0))
150 * When generating ridiculously small keys, we can get stuck
151 * continually regenerating the same prime values. Check for this and
152 * bail if it happens 3 times.
154 unsigned int degenerate = 0;
156 if (!BN_generate_prime_ex(rsa->q, bitsq, 0, NULL, NULL, cb))
158 } while ((BN_cmp(rsa->p, rsa->q) == 0) && (++degenerate < 3));
159 if (degenerate == 3) {
160 ok = 0; /* we set our own err */
161 RSAerr(RSA_F_RSA_BUILTIN_KEYGEN, RSA_R_KEY_SIZE_TOO_SMALL);
164 if (!BN_sub(r2, rsa->q, BN_value_one()))
166 if (!BN_gcd(r1, r2, rsa->e, ctx))
170 if (!BN_GENCB_call(cb, 2, n++))
173 if (!BN_GENCB_call(cb, 3, 1))
175 if (BN_cmp(rsa->p, rsa->q) < 0) {
182 if (!BN_mul(rsa->n, rsa->p, rsa->q, ctx))
186 if (!BN_sub(r1, rsa->p, BN_value_one()))
188 if (!BN_sub(r2, rsa->q, BN_value_one()))
190 if (!BN_mul(r0, r1, r2, ctx))
191 goto err; /* (p-1)(q-1) */
192 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
194 BN_with_flags(pr0, r0, BN_FLG_CONSTTIME);
197 if (!BN_mod_inverse(rsa->d, rsa->e, pr0, ctx))
200 /* set up d for correct BN_FLG_CONSTTIME flag */
201 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
203 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
207 /* calculate d mod (p-1) */
208 if (!BN_mod(rsa->dmp1, d, r1, ctx))
211 /* calculate d mod (q-1) */
212 if (!BN_mod(rsa->dmq1, d, r2, ctx))
215 /* calculate inverse of q mod p */
216 if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
218 BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME);
221 if (!BN_mod_inverse(rsa->iqmp, rsa->q, p, ctx))
227 RSAerr(RSA_F_RSA_BUILTIN_KEYGEN, ERR_LIB_BN);