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 are
  61  * compatibility wrappers using these functions) are in rsa_depr.c.
  62  * - Geoff
  63  */
  64
  65 #define OPENSSL_FIPSAPI
  66
  67 #include <stdio.h>
  68 #include <time.h>
  69 #include "cryptlib.h"
  70 #include <openssl/bn.h>
  71 #include <openssl/rsa.h>
  72
  73 #ifdef OPENSSL_FIPS
  74
  75
  76 #include <openssl/fips.h>
  77 #include <openssl/fips_rand.h>
  78 #include <openssl/evp.h>
  79
  80 /* Check PRNG has sufficient security level to handle an RSA operation */
  81
  82 int fips_check_rsa_prng(RSA *rsa, int bits)
  83         {
  84         int strength;
  85         if (!FIPS_mode())
  86                 return 1;
  87
  88         if (rsa->flags & (RSA_FLAG_NON_FIPS_ALLOW|RSA_FLAG_CHECKED))
  89                 return 1;
  90
  91         if (bits == 0)
  92                 bits = BN_num_bits(rsa->n);
  93
  94         /* Should never happen */
  95         if (bits < 1024)
  96                 {
  97                 FIPSerr(FIPS_F_FIPS_CHECK_RSA_PRNG,FIPS_R_KEY_TOO_SHORT);
  98                 return 0;
  99                 }
 100         /* From SP800-57 */
 101         if (bits < 2048)
 102                 strength = 80;
 103         else if (bits < 3072)
 104                 strength = 112;
 105         else if (bits < 7680)
 106                 strength = 128;
 107         else if (bits < 15360)
 108                 strength = 192;
 109         else
 110                 strength = 256;
 111
 112         if (FIPS_rand_strength() >= strength)
 113                 return 1;
 114
 115         FIPSerr(FIPS_F_FIPS_CHECK_RSA_PRNG,FIPS_R_PRNG_STRENGTH_TOO_LOW);
 116         return 0;
 117         }
 118
 119
 120 int fips_check_rsa(RSA *rsa)
 121         {
 122         const unsigned char tbs[] = "RSA Pairwise Check Data";
 123         unsigned char *ctbuf = NULL, *ptbuf = NULL;
 124         int len, ret = 0;
 125         EVP_PKEY pk;
 126         pk.type = EVP_PKEY_RSA;
 127         pk.pkey.rsa = rsa;
 128
 129         /* Perform pairwise consistency signature test */
 130         if (!fips_pkey_signature_test(FIPS_TEST_PAIRWISE, &pk, tbs, 0,
 131                         NULL, 0, NULL, RSA_PKCS1_PADDING, NULL)
 132                 || !fips_pkey_signature_test(FIPS_TEST_PAIRWISE, &pk, tbs, 0,
 133                         NULL, 0, NULL, RSA_X931_PADDING, NULL)
 134                 || !fips_pkey_signature_test(FIPS_TEST_PAIRWISE, &pk, tbs, 0,
 135                         NULL, 0, NULL, RSA_PKCS1_PSS_PADDING, NULL))
 136                 goto err;
 137         /* Now perform pairwise consistency encrypt/decrypt test */
 138         ctbuf = OPENSSL_malloc(RSA_size(rsa));
 139         if (!ctbuf)
 140                 goto err;
 141
 142         len = RSA_public_encrypt(sizeof(tbs) - 1, tbs, ctbuf, rsa, RSA_PKCS1_PADDING);
 143         if (len <= 0)
 144                 goto err;
 145         /* Check ciphertext doesn't match plaintext */
 146         if ((len == (sizeof(tbs) - 1)) && !memcmp(tbs, ctbuf, len))
 147                 goto err;
 148         ptbuf = OPENSSL_malloc(RSA_size(rsa));
 149
 150         if (!ptbuf)
 151                 goto err;
 152         len = RSA_private_decrypt(len, ctbuf, ptbuf, rsa, RSA_PKCS1_PADDING);
 153         if (len != (sizeof(tbs) - 1))
 154                 goto err;
 155         if (memcmp(ptbuf, tbs, len))
 156                 goto err;
 157
 158         ret = 1;
 159
 160         if (!ptbuf)
 161                 goto err;
 162
 163         err:
 164         if (ret == 0)
 165                 {
 166                 fips_set_selftest_fail();
 167                 FIPSerr(FIPS_F_FIPS_CHECK_RSA,FIPS_R_PAIRWISE_TEST_FAILED);
 168                 }
 169
 170         if (ctbuf)
 171                 OPENSSL_free(ctbuf);
 172         if (ptbuf)
 173                 OPENSSL_free(ptbuf);
 174
 175         return ret;
 176         }
 177 #endif
 178
 179 static int rsa_builtin_keygen(RSA *rsa, int bits, BIGNUM *e_value, BN_GENCB *cb);
 180
 181 /* NB: this wrapper would normally be placed in rsa_lib.c and the static
 182  * implementation would probably be in rsa_eay.c. Nonetheless, is kept here so
 183  * that we don't introduce a new linker dependency. Eg. any application that
 184  * wasn't previously linking object code related to key-generation won't have to
 185  * now just because key-generation is part of RSA_METHOD. */
 186 int RSA_generate_key_ex(RSA *rsa, int bits, BIGNUM *e_value, BN_GENCB *cb)
 187         {
 188         if(rsa->meth->rsa_keygen)
 189                 return rsa->meth->rsa_keygen(rsa, bits, e_value, cb);
 190         return rsa_builtin_keygen(rsa, bits, e_value, cb);
 191         }
 192
 193 static int rsa_builtin_keygen(RSA *rsa, int bits, BIGNUM *e_value, BN_GENCB *cb)
 194         {
 195         BIGNUM *r0=NULL,*r1=NULL,*r2=NULL,*r3=NULL,*tmp;
 196         BIGNUM local_r0,local_d,local_p;
 197         BIGNUM *pr0,*d,*p;
 198         int bitsp,bitsq,ok= -1,n=0;
 199         BN_CTX *ctx=NULL;
 200
 201 #ifdef OPENSSL_FIPS
 202         if(FIPS_selftest_failed())
 203             {
 204             FIPSerr(FIPS_F_RSA_BUILTIN_KEYGEN,FIPS_R_FIPS_SELFTEST_FAILED);
 205             return 0;
 206             }
 207
 208         if (FIPS_mode() && !(rsa->flags & RSA_FLAG_NON_FIPS_ALLOW)
 209                 && (bits < OPENSSL_RSA_FIPS_MIN_MODULUS_BITS))
 210             {
 211             FIPSerr(FIPS_F_RSA_BUILTIN_KEYGEN,FIPS_R_KEY_TOO_SHORT);
 212             return 0;
 213             }
 214         if (!fips_check_rsa_prng(rsa, bits))
 215             return 0;
 216 #endif
 217
 218         ctx=BN_CTX_new();
 219         if (ctx == NULL) goto err;
 220         BN_CTX_start(ctx);
 221         r0 = BN_CTX_get(ctx);
 222         r1 = BN_CTX_get(ctx);
 223         r2 = BN_CTX_get(ctx);
 224         r3 = BN_CTX_get(ctx);
 225         if (r3 == NULL) goto err;
 226
 227         bitsp=(bits+1)/2;
 228         bitsq=bits-bitsp;
 229
 230         /* We need the RSA components non-NULL */
 231         if(!rsa->n && ((rsa->n=BN_new()) == NULL)) goto err;
 232         if(!rsa->d && ((rsa->d=BN_new()) == NULL)) goto err;
 233         if(!rsa->e && ((rsa->e=BN_new()) == NULL)) goto err;
 234         if(!rsa->p && ((rsa->p=BN_new()) == NULL)) goto err;
 235         if(!rsa->q && ((rsa->q=BN_new()) == NULL)) goto err;
 236         if(!rsa->dmp1 && ((rsa->dmp1=BN_new()) == NULL)) goto err;
 237         if(!rsa->dmq1 && ((rsa->dmq1=BN_new()) == NULL)) goto err;
 238         if(!rsa->iqmp && ((rsa->iqmp=BN_new()) == NULL)) goto err;
 239
 240         BN_copy(rsa->e, e_value);
 241
 242         /* generate p and q */
 243         for (;;)
 244                 {
 245                 if(!BN_generate_prime_ex(rsa->p, bitsp, 0, NULL, NULL, cb))
 246                         goto err;
 247                 if (!BN_sub(r2,rsa->p,BN_value_one())) goto err;
 248                 if (!BN_gcd(r1,r2,rsa->e,ctx)) goto err;
 249                 if (BN_is_one(r1)) break;
 250                 if(!BN_GENCB_call(cb, 2, n++))
 251                         goto err;
 252                 }
 253         if(!BN_GENCB_call(cb, 3, 0))
 254                 goto err;
 255         for (;;)
 256                 {
 257                 /* When generating ridiculously small keys, we can get stuck
 258                  * continually regenerating the same prime values. Check for
 259                  * this and bail if it happens 3 times. */
 260                 unsigned int degenerate = 0;
 261                 do
 262                         {
 263                         if(!BN_generate_prime_ex(rsa->q, bitsq, 0, NULL, NULL, cb))
 264                                 goto err;
 265                         } while((BN_cmp(rsa->p, rsa->q) == 0) && (++degenerate < 3));
 266                 if(degenerate == 3)
 267                         {
 268                         ok = 0; /* we set our own err */
 269                         RSAerr(RSA_F_RSA_BUILTIN_KEYGEN,RSA_R_KEY_SIZE_TOO_SMALL);
 270                         goto err;
 271                         }
 272                 if (!BN_sub(r2,rsa->q,BN_value_one())) goto err;
 273                 if (!BN_gcd(r1,r2,rsa->e,ctx)) goto err;
 274                 if (BN_is_one(r1))
 275                         break;
 276                 if(!BN_GENCB_call(cb, 2, n++))
 277                         goto err;
 278                 }
 279         if(!BN_GENCB_call(cb, 3, 1))
 280                 goto err;
 281         if (BN_cmp(rsa->p,rsa->q) < 0)
 282                 {
 283                 tmp=rsa->p;
 284                 rsa->p=rsa->q;
 285                 rsa->q=tmp;
 286                 }
 287
 288         /* calculate n */
 289         if (!BN_mul(rsa->n,rsa->p,rsa->q,ctx)) goto err;
 290
 291         /* calculate d */
 292         if (!BN_sub(r1,rsa->p,BN_value_one())) goto err;        /* p-1 */
 293         if (!BN_sub(r2,rsa->q,BN_value_one())) goto err;        /* q-1 */
 294         if (!BN_mul(r0,r1,r2,ctx)) goto err;    /* (p-1)(q-1) */
 295         if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
 296                 {
 297                   pr0 = &local_r0;
 298                   BN_with_flags(pr0, r0, BN_FLG_CONSTTIME);
 299                 }
 300         else
 301           pr0 = r0;
 302         if (!BN_mod_inverse(rsa->d,rsa->e,pr0,ctx)) goto err;   /* d */
 303
 304         /* set up d for correct BN_FLG_CONSTTIME flag */
 305         if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
 306                 {
 307                 d = &local_d;
 308                 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
 309                 }
 310         else
 311                 d = rsa->d;
 312
 313         /* calculate d mod (p-1) */
 314         if (!BN_mod(rsa->dmp1,d,r1,ctx)) goto err;
 315
 316         /* calculate d mod (q-1) */
 317         if (!BN_mod(rsa->dmq1,d,r2,ctx)) goto err;
 318
 319         /* calculate inverse of q mod p */
 320         if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
 321                 {
 322                 p = &local_p;
 323                 BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME);
 324                 }
 325         else
 326                 p = rsa->p;
 327         if (!BN_mod_inverse(rsa->iqmp,rsa->q,p,ctx)) goto err;
 328
 329 #ifdef OPENSSL_FIPS
 330         if(!fips_check_rsa(rsa))
 331             goto err;
 332 #endif
 333
 334         ok=1;
 335 err:
 336         if (ok == -1)
 337                 {
 338                 RSAerr(RSA_F_RSA_BUILTIN_KEYGEN,ERR_LIB_BN);
 339                 ok=0;
 340                 }
 341         if (ctx != NULL)
 342                 {
 343                 BN_CTX_end(ctx);
 344                 BN_CTX_free(ctx);
 345                 }
 346
 347         return ok;
 348         }
 349