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/evp.h>
  78
  79 static int fips_rsa_pairwise_fail = 0;
  80
  81 void FIPS_corrupt_rsa_keygen(void)
  82         {
  83         fips_rsa_pairwise_fail = 1;
  84         }
  85
  86 int fips_check_rsa(RSA *rsa)
  87         {
  88         const unsigned char tbs[] = "RSA Pairwise Check Data";
  89         unsigned char *ctbuf = NULL, *ptbuf = NULL;
  90         int len, ret = 0;
  91         EVP_PKEY pk;
  92         pk.type = EVP_PKEY_RSA;
  93         pk.pkey.rsa = rsa;
  94
  95         /* Perform pairwise consistency signature test */
  96         if (!fips_pkey_signature_test(&pk, tbs, -1,
  97                         NULL, 0, NULL, RSA_PKCS1_PADDING, NULL)
  98                 || !fips_pkey_signature_test(&pk, tbs, -1,
  99                         NULL, 0, NULL, RSA_X931_PADDING, NULL)
 100                 || !fips_pkey_signature_test(&pk, tbs, -1,
 101                         NULL, 0, NULL, RSA_PKCS1_PSS_PADDING, NULL))
 102                 goto err;
 103         /* Now perform pairwise consistency encrypt/decrypt test */
 104         ctbuf = OPENSSL_malloc(RSA_size(rsa));
 105         if (!ctbuf)
 106                 goto err;
 107
 108         len = RSA_public_encrypt(sizeof(tbs) - 1, tbs, ctbuf, rsa, RSA_PKCS1_PADDING);
 109         if (len <= 0)
 110                 goto err;
 111         /* Check ciphertext doesn't match plaintext */
 112         if ((len == (sizeof(tbs) - 1)) && !memcmp(tbs, ctbuf, len))
 113                 goto err;
 114         ptbuf = OPENSSL_malloc(RSA_size(rsa));
 115
 116         if (!ptbuf)
 117                 goto err;
 118         len = RSA_private_decrypt(len, ctbuf, ptbuf, rsa, RSA_PKCS1_PADDING);
 119         if (len != (sizeof(tbs) - 1))
 120                 goto err;
 121         if (memcmp(ptbuf, tbs, len))
 122                 goto err;
 123
 124         ret = 1;
 125
 126         if (!ptbuf)
 127                 goto err;
 128
 129         err:
 130         if (ret == 0)
 131                 {
 132                 fips_set_selftest_fail();
 133                 FIPSerr(FIPS_F_FIPS_CHECK_RSA,FIPS_R_PAIRWISE_TEST_FAILED);
 134                 }
 135
 136         if (ctbuf)
 137                 OPENSSL_free(ctbuf);
 138         if (ptbuf)
 139                 OPENSSL_free(ptbuf);
 140
 141         return ret;
 142         }
 143 #endif
 144
 145 static int rsa_builtin_keygen(RSA *rsa, int bits, BIGNUM *e_value, BN_GENCB *cb);
 146
 147 /* NB: this wrapper would normally be placed in rsa_lib.c and the static
 148  * implementation would probably be in rsa_eay.c. Nonetheless, is kept here so
 149  * that we don't introduce a new linker dependency. Eg. any application that
 150  * wasn't previously linking object code related to key-generation won't have to
 151  * now just because key-generation is part of RSA_METHOD. */
 152 int RSA_generate_key_ex(RSA *rsa, int bits, BIGNUM *e_value, BN_GENCB *cb)
 153         {
 154         if(rsa->meth->rsa_keygen)
 155                 return rsa->meth->rsa_keygen(rsa, bits, e_value, cb);
 156         return rsa_builtin_keygen(rsa, bits, e_value, cb);
 157         }
 158
 159 static int rsa_builtin_keygen(RSA *rsa, int bits, BIGNUM *e_value, BN_GENCB *cb)
 160         {
 161         BIGNUM *r0=NULL,*r1=NULL,*r2=NULL,*r3=NULL,*tmp;
 162         BIGNUM local_r0,local_d,local_p;
 163         BIGNUM *pr0,*d,*p;
 164         int bitsp,bitsq,ok= -1,n=0;
 165         BN_CTX *ctx=NULL;
 166
 167 #ifdef OPENSSL_FIPS
 168         if(FIPS_selftest_failed())
 169             {
 170             FIPSerr(FIPS_F_RSA_BUILTIN_KEYGEN,FIPS_R_FIPS_SELFTEST_FAILED);
 171             return 0;
 172             }
 173
 174         if (FIPS_mode() && (bits < OPENSSL_RSA_FIPS_MIN_MODULUS_BITS))
 175             {
 176             FIPSerr(FIPS_F_RSA_BUILTIN_KEYGEN,FIPS_R_KEY_TOO_SHORT);
 177             return 0;
 178             }
 179 #endif
 180
 181         ctx=BN_CTX_new();
 182         if (ctx == NULL) goto err;
 183         BN_CTX_start(ctx);
 184         r0 = BN_CTX_get(ctx);
 185         r1 = BN_CTX_get(ctx);
 186         r2 = BN_CTX_get(ctx);
 187         r3 = BN_CTX_get(ctx);
 188         if (r3 == NULL) goto err;
 189
 190         bitsp=(bits+1)/2;
 191         bitsq=bits-bitsp;
 192
 193         /* We need the RSA components non-NULL */
 194         if(!rsa->n && ((rsa->n=BN_new()) == NULL)) goto err;
 195         if(!rsa->d && ((rsa->d=BN_new()) == NULL)) goto err;
 196         if(!rsa->e && ((rsa->e=BN_new()) == NULL)) goto err;
 197         if(!rsa->p && ((rsa->p=BN_new()) == NULL)) goto err;
 198         if(!rsa->q && ((rsa->q=BN_new()) == NULL)) goto err;
 199         if(!rsa->dmp1 && ((rsa->dmp1=BN_new()) == NULL)) goto err;
 200         if(!rsa->dmq1 && ((rsa->dmq1=BN_new()) == NULL)) goto err;
 201         if(!rsa->iqmp && ((rsa->iqmp=BN_new()) == NULL)) goto err;
 202
 203         BN_copy(rsa->e, e_value);
 204
 205         /* generate p and q */
 206         for (;;)
 207                 {
 208                 if(!BN_generate_prime_ex(rsa->p, bitsp, 0, NULL, NULL, cb))
 209                         goto err;
 210                 if (!BN_sub(r2,rsa->p,BN_value_one())) goto err;
 211                 if (!BN_gcd(r1,r2,rsa->e,ctx)) goto err;
 212                 if (BN_is_one(r1)) break;
 213                 if(!BN_GENCB_call(cb, 2, n++))
 214                         goto err;
 215                 }
 216         if(!BN_GENCB_call(cb, 3, 0))
 217                 goto err;
 218         for (;;)
 219                 {
 220                 /* When generating ridiculously small keys, we can get stuck
 221                  * continually regenerating the same prime values. Check for
 222                  * this and bail if it happens 3 times. */
 223                 unsigned int degenerate = 0;
 224                 do
 225                         {
 226                         if(!BN_generate_prime_ex(rsa->q, bitsq, 0, NULL, NULL, cb))
 227                                 goto err;
 228                         } while((BN_cmp(rsa->p, rsa->q) == 0) && (++degenerate < 3));
 229                 if(degenerate == 3)
 230                         {
 231                         ok = 0; /* we set our own err */
 232                         RSAerr(RSA_F_RSA_BUILTIN_KEYGEN,RSA_R_KEY_SIZE_TOO_SMALL);
 233                         goto err;
 234                         }
 235                 if (!BN_sub(r2,rsa->q,BN_value_one())) goto err;
 236                 if (!BN_gcd(r1,r2,rsa->e,ctx)) goto err;
 237                 if (BN_is_one(r1))
 238                         break;
 239                 if(!BN_GENCB_call(cb, 2, n++))
 240                         goto err;
 241                 }
 242         if(!BN_GENCB_call(cb, 3, 1))
 243                 goto err;
 244         if (BN_cmp(rsa->p,rsa->q) < 0)
 245                 {
 246                 tmp=rsa->p;
 247                 rsa->p=rsa->q;
 248                 rsa->q=tmp;
 249                 }
 250
 251         /* calculate n */
 252         if (!BN_mul(rsa->n,rsa->p,rsa->q,ctx)) goto err;
 253
 254         /* calculate d */
 255         if (!BN_sub(r1,rsa->p,BN_value_one())) goto err;        /* p-1 */
 256         if (!BN_sub(r2,rsa->q,BN_value_one())) goto err;        /* q-1 */
 257         if (!BN_mul(r0,r1,r2,ctx)) goto err;    /* (p-1)(q-1) */
 258         if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
 259                 {
 260                   pr0 = &local_r0;
 261                   BN_with_flags(pr0, r0, BN_FLG_CONSTTIME);
 262                 }
 263         else
 264           pr0 = r0;
 265         if (!BN_mod_inverse(rsa->d,rsa->e,pr0,ctx)) goto err;   /* d */
 266
 267         /* set up d for correct BN_FLG_CONSTTIME flag */
 268         if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
 269                 {
 270                 d = &local_d;
 271                 BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
 272                 }
 273         else
 274                 d = rsa->d;
 275
 276         /* calculate d mod (p-1) */
 277         if (!BN_mod(rsa->dmp1,d,r1,ctx)) goto err;
 278
 279         /* calculate d mod (q-1) */
 280         if (!BN_mod(rsa->dmq1,d,r2,ctx)) goto err;
 281
 282         /* calculate inverse of q mod p */
 283         if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME))
 284                 {
 285                 p = &local_p;
 286                 BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME);
 287                 }
 288         else
 289                 p = rsa->p;
 290         if (!BN_mod_inverse(rsa->iqmp,rsa->q,p,ctx)) goto err;
 291
 292 #ifdef OPENSSL_FIPS
 293         if (fips_rsa_pairwise_fail)
 294                 BN_add_word(rsa->n, 1);
 295
 296         if(!fips_check_rsa(rsa))
 297             goto err;
 298 #endif
 299
 300         ok=1;
 301 err:
 302         if (ok == -1)
 303                 {
 304                 RSAerr(RSA_F_RSA_BUILTIN_KEYGEN,ERR_LIB_BN);
 305                 ok=0;
 306                 }
 307         if (ctx != NULL)
 308                 {
 309                 BN_CTX_end(ctx);
 310                 BN_CTX_free(ctx);
 311                 }
 312
 313         return ok;
 314         }
 315