release/src/router/openssl/crypto/rsa/rsa_gen.c

   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 "cryptlib.h"
  68 #include <openssl/bn.h>
  69 #include <openssl/rsa.h>
  70 #ifdef OPENSSL_FIPS
  71 # include <openssl/fips.h>
  72 #endif
  73
  74 static int rsa_builtin_keygen(RSA *rsa, int bits, BIGNUM *e_value,
  75                               BN_GENCB *cb);
  76
  77 /*
  78  * NB: this wrapper would normally be placed in rsa_lib.c and the static
  79  * implementation would probably be in rsa_eay.c. Nonetheless, is kept here
  80  * so that we don't introduce a new linker dependency. Eg. any application
  81  * that wasn't previously linking object code related to key-generation won't
  82  * have to now just because key-generation is part of RSA_METHOD.
  83  */
  84 int RSA_generate_key_ex(RSA *rsa, int bits, BIGNUM *e_value, BN_GENCB *cb)
  85 {
  86 #ifdef OPENSSL_FIPS
  87     if (FIPS_mode() && !(rsa->meth->flags & RSA_FLAG_FIPS_METHOD)
  88         && !(rsa->flags & RSA_FLAG_NON_FIPS_ALLOW)) {
  89         RSAerr(RSA_F_RSA_GENERATE_KEY_EX, RSA_R_NON_FIPS_RSA_METHOD);
  90         return 0;
  91     }
  92 #endif
  93     if (rsa->meth->rsa_keygen)
  94         return rsa->meth->rsa_keygen(rsa, bits, e_value, cb);
  95 #ifdef OPENSSL_FIPS
  96     if (FIPS_mode())
  97         return FIPS_rsa_generate_key_ex(rsa, bits, e_value, cb);
  98 #endif
  99     return rsa_builtin_keygen(rsa, bits, e_value, cb);
 100 }
 101
 102 static int rsa_builtin_keygen(RSA *rsa, int bits, BIGNUM *e_value,
 103                               BN_GENCB *cb)
 104 {
 105     BIGNUM *r0 = NULL, *r1 = NULL, *r2 = NULL, *r3 = NULL, *tmp;
 106     BIGNUM local_r0, local_d, local_p;
 107     BIGNUM *pr0, *d, *p;
 108     int bitsp, bitsq, ok = -1, n = 0;
 109     BN_CTX *ctx = NULL;
 110
 111     ctx = BN_CTX_new();
 112     if (ctx == NULL)
 113         goto err;
 114     BN_CTX_start(ctx);
 115     r0 = BN_CTX_get(ctx);
 116     r1 = BN_CTX_get(ctx);
 117     r2 = BN_CTX_get(ctx);
 118     r3 = BN_CTX_get(ctx);
 119     if (r3 == NULL)
 120         goto err;
 121
 122     bitsp = (bits + 1) / 2;
 123     bitsq = bits - bitsp;
 124
 125     /* We need the RSA components non-NULL */
 126     if (!rsa->n && ((rsa->n = BN_new()) == NULL))
 127         goto err;
 128     if (!rsa->d && ((rsa->d = BN_new()) == NULL))
 129         goto err;
 130     if (!rsa->e && ((rsa->e = BN_new()) == NULL))
 131         goto err;
 132     if (!rsa->p && ((rsa->p = BN_new()) == NULL))
 133         goto err;
 134     if (!rsa->q && ((rsa->q = BN_new()) == NULL))
 135         goto err;
 136     if (!rsa->dmp1 && ((rsa->dmp1 = BN_new()) == NULL))
 137         goto err;
 138     if (!rsa->dmq1 && ((rsa->dmq1 = BN_new()) == NULL))
 139         goto err;
 140     if (!rsa->iqmp && ((rsa->iqmp = BN_new()) == NULL))
 141         goto err;
 142
 143     BN_copy(rsa->e, e_value);
 144
 145     /* generate p and q */
 146     for (;;) {
 147         if (!BN_generate_prime_ex(rsa->p, bitsp, 0, NULL, NULL, cb))
 148             goto err;
 149         if (!BN_sub(r2, rsa->p, BN_value_one()))
 150             goto err;
 151         if (!BN_gcd(r1, r2, rsa->e, ctx))
 152             goto err;
 153         if (BN_is_one(r1))
 154             break;
 155         if (!BN_GENCB_call(cb, 2, n++))
 156             goto err;
 157     }
 158     if (!BN_GENCB_call(cb, 3, 0))
 159         goto err;
 160     for (;;) {
 161         /*
 162          * When generating ridiculously small keys, we can get stuck
 163          * continually regenerating the same prime values. Check for this and
 164          * bail if it happens 3 times.
 165          */
 166         unsigned int degenerate = 0;
 167         do {
 168             if (!BN_generate_prime_ex(rsa->q, bitsq, 0, NULL, NULL, cb))
 169                 goto err;
 170         } while ((BN_cmp(rsa->p, rsa->q) == 0) && (++degenerate < 3));
 171         if (degenerate == 3) {
 172             ok = 0;             /* we set our own err */
 173             RSAerr(RSA_F_RSA_BUILTIN_KEYGEN, RSA_R_KEY_SIZE_TOO_SMALL);
 174             goto err;
 175         }
 176         if (!BN_sub(r2, rsa->q, BN_value_one()))
 177             goto err;
 178         if (!BN_gcd(r1, r2, rsa->e, ctx))
 179             goto err;
 180         if (BN_is_one(r1))
 181             break;
 182         if (!BN_GENCB_call(cb, 2, n++))
 183             goto err;
 184     }
 185     if (!BN_GENCB_call(cb, 3, 1))
 186         goto err;
 187     if (BN_cmp(rsa->p, rsa->q) < 0) {
 188         tmp = rsa->p;
 189         rsa->p = rsa->q;
 190         rsa->q = tmp;
 191     }
 192
 193     /* calculate n */
 194     if (!BN_mul(rsa->n, rsa->p, rsa->q, ctx))
 195         goto err;
 196
 197     /* calculate d */
 198     if (!BN_sub(r1, rsa->p, BN_value_one()))
 199         goto err;               /* p-1 */
 200     if (!BN_sub(r2, rsa->q, BN_value_one()))
 201         goto err;               /* q-1 */
 202     if (!BN_mul(r0, r1, r2, ctx))
 203         goto err;               /* (p-1)(q-1) */
 204     if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
 205         pr0 = &local_r0;
 206         BN_with_flags(pr0, r0, BN_FLG_CONSTTIME);
 207     } else
 208         pr0 = r0;
 209     if (!BN_mod_inverse(rsa->d, rsa->e, pr0, ctx))
 210         goto err;               /* d */
 211
 212     /* set up d for correct BN_FLG_CONSTTIME flag */
 213     if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
 214         d = &local_d;
 215         BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
 216     } else
 217         d = rsa->d;
 218
 219     /* calculate d mod (p-1) */
 220     if (!BN_mod(rsa->dmp1, d, r1, ctx))
 221         goto err;
 222
 223     /* calculate d mod (q-1) */
 224     if (!BN_mod(rsa->dmq1, d, r2, ctx))
 225         goto err;
 226
 227     /* calculate inverse of q mod p */
 228     if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
 229         p = &local_p;
 230         BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME);
 231     } else
 232         p = rsa->p;
 233     if (!BN_mod_inverse(rsa->iqmp, rsa->q, p, ctx))
 234         goto err;
 235
 236     ok = 1;
 237  err:
 238     if (ok == -1) {
 239         RSAerr(RSA_F_RSA_BUILTIN_KEYGEN, ERR_LIB_BN);
 240         ok = 0;
 241     }
 242     if (ctx != NULL) {
 243         BN_CTX_end(ctx);
 244         BN_CTX_free(ctx);
 245     }
 246
 247     return ok;
 248 }