2 * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
11 * NB: these functions have been "upgraded", the deprecated versions (which
12 * are compatibility wrappers using these functions) are in rsa_depr.c. -
18 #include "internal/cryptlib.h"
19 #include <openssl/bn.h>
22 static int rsa_builtin_keygen(RSA *rsa, int bits, BIGNUM *e_value,
26 * NB: this wrapper would normally be placed in rsa_lib.c and the static
27 * implementation would probably be in rsa_eay.c. Nonetheless, is kept here
28 * so that we don't introduce a new linker dependency. Eg. any application
29 * that wasn't previously linking object code related to key-generation won't
30 * have to now just because key-generation is part of RSA_METHOD.
32 int RSA_generate_key_ex(RSA *rsa, int bits, BIGNUM *e_value, BN_GENCB *cb)
34 if (rsa->meth->rsa_keygen)
35 return rsa->meth->rsa_keygen(rsa, bits, e_value, cb);
36 return rsa_builtin_keygen(rsa, bits, e_value, cb);
39 static int rsa_builtin_keygen(RSA *rsa, int bits, BIGNUM *e_value,
42 BIGNUM *r0 = NULL, *r1 = NULL, *r2 = NULL, *r3 = NULL, *tmp;
43 int bitsp, bitsq, ok = -1, n = 0;
57 bitsp = (bits + 1) / 2;
60 /* We need the RSA components non-NULL */
61 if (!rsa->n && ((rsa->n = BN_new()) == NULL))
63 if (!rsa->d && ((rsa->d = BN_secure_new()) == NULL))
65 if (!rsa->e && ((rsa->e = BN_new()) == NULL))
67 if (!rsa->p && ((rsa->p = BN_secure_new()) == NULL))
69 if (!rsa->q && ((rsa->q = BN_secure_new()) == NULL))
71 if (!rsa->dmp1 && ((rsa->dmp1 = BN_secure_new()) == NULL))
73 if (!rsa->dmq1 && ((rsa->dmq1 = BN_secure_new()) == NULL))
75 if (!rsa->iqmp && ((rsa->iqmp = BN_secure_new()) == NULL))
78 BN_copy(rsa->e, e_value);
80 /* generate p and q */
82 if (!BN_generate_prime_ex(rsa->p, bitsp, 0, NULL, NULL, cb))
84 if (!BN_sub(r2, rsa->p, BN_value_one()))
86 if (!BN_gcd(r1, r2, rsa->e, ctx))
90 if (!BN_GENCB_call(cb, 2, n++))
93 if (!BN_GENCB_call(cb, 3, 0))
97 * When generating ridiculously small keys, we can get stuck
98 * continually regenerating the same prime values. Check for this and
99 * bail if it happens 3 times.
101 unsigned int degenerate = 0;
103 if (!BN_generate_prime_ex(rsa->q, bitsq, 0, NULL, NULL, cb))
105 } while ((BN_cmp(rsa->p, rsa->q) == 0) && (++degenerate < 3));
106 if (degenerate == 3) {
107 ok = 0; /* we set our own err */
108 RSAerr(RSA_F_RSA_BUILTIN_KEYGEN, RSA_R_KEY_SIZE_TOO_SMALL);
111 if (!BN_sub(r2, rsa->q, BN_value_one()))
113 if (!BN_gcd(r1, r2, rsa->e, ctx))
117 if (!BN_GENCB_call(cb, 2, n++))
120 if (!BN_GENCB_call(cb, 3, 1))
122 if (BN_cmp(rsa->p, rsa->q) < 0) {
129 if (!BN_mul(rsa->n, rsa->p, rsa->q, ctx))
133 if (!BN_sub(r1, rsa->p, BN_value_one()))
135 if (!BN_sub(r2, rsa->q, BN_value_one()))
137 if (!BN_mul(r0, r1, r2, ctx))
138 goto err; /* (p-1)(q-1) */
140 BIGNUM *pr0 = BN_new();
144 BN_with_flags(pr0, r0, BN_FLG_CONSTTIME);
145 if (!BN_mod_inverse(rsa->d, rsa->e, pr0, ctx)) {
149 /* We MUST free pr0 before any further use of r0 */
154 BIGNUM *d = BN_new();
158 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
160 if ( /* calculate d mod (p-1) */
161 !BN_mod(rsa->dmp1, d, r1, ctx)
162 /* calculate d mod (q-1) */
163 || !BN_mod(rsa->dmq1, d, r2, ctx)) {
167 /* We MUST free d before any further use of rsa->d */
172 BIGNUM *p = BN_new();
176 BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME);
178 /* calculate inverse of q mod p */
179 if (!BN_mod_inverse(rsa->iqmp, rsa->q, p, ctx)) {
183 /* We MUST free p before any further use of rsa->p */
190 RSAerr(RSA_F_RSA_BUILTIN_KEYGEN, ERR_LIB_BN);