engines/e_gmp.c

   1 /* crypto/engine/e_gmp.c */
   2 /* Written by Geoff Thorpe (geoff@geoffthorpe.net) for the OpenSSL
   3  * project 2003.
   4  */
   5 /* ====================================================================
   6  * Copyright (c) 1999-2001 The OpenSSL Project.  All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  *
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in
  17  *    the documentation and/or other materials provided with the
  18  *    distribution.
  19  *
  20  * 3. All advertising materials mentioning features or use of this
  21  *    software must display the following acknowledgment:
  22  *    "This product includes software developed by the OpenSSL Project
  23  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
  24  *
  25  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  26  *    endorse or promote products derived from this software without
  27  *    prior written permission. For written permission, please contact
  28  *    licensing@OpenSSL.org.
  29  *
  30  * 5. Products derived from this software may not be called "OpenSSL"
  31  *    nor may "OpenSSL" appear in their names without prior written
  32  *    permission of the OpenSSL Project.
  33  *
  34  * 6. Redistributions of any form whatsoever must retain the following
  35  *    acknowledgment:
  36  *    "This product includes software developed by the OpenSSL Project
  37  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
  38  *
  39  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  40  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  41  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  42  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  43  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  44  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  45  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  46  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  48  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  49  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  50  * OF THE POSSIBILITY OF SUCH DAMAGE.
  51  * ====================================================================
  52  *
  53  * This product includes cryptographic software written by Eric Young
  54  * (eay@cryptsoft.com).  This product includes software written by Tim
  55  * Hudson (tjh@cryptsoft.com).
  56  *
  57  */
  58
  59 /* This engine is not (currently) compiled in by default. Do enable it,
  60  * reconfigure OpenSSL with "enable-gmp -lgmp". The GMP libraries and
  61  * headers must reside in one of the paths searched by the compiler/linker,
  62  * otherwise paths must be specified - eg. try configuring with
  63  * "enable-gmp -I<includepath> -L<libpath> -lgmp". YMMV. */
  64
  65 /* As for what this does - it's a largely unoptimised implementation of an
  66  * ENGINE that uses the GMP library to perform RSA private key operations. To
  67  * obtain more information about what "unoptimised" means, see my original mail
  68  * on the subject (though ignore the build instructions which have since
  69  * changed);
  70  *
  71  *    http://www.mail-archive.com/openssl-dev@openssl.org/msg12227.html
  72  *
  73  * On my athlon system at least, it appears the builtin OpenSSL code is now
  74  * slightly faster, which is to say that the RSA-related MPI performance
  75  * between OpenSSL's BIGNUM and GMP's mpz implementations is probably pretty
  76  * balanced for this chip, and so the performance degradation in this ENGINE by
  77  * having to convert to/from GMP formats (and not being able to cache
  78  * montgomery forms) is probably the difference. However, if some unconfirmed
  79  * reports from users is anything to go by, the situation on some other
  80  * chipsets might be a good deal more favourable to the GMP version (eg. PPC).
  81  * Feedback welcome. */
  82
  83 #include <stdio.h>
  84 #include <string.h>
  85 #include <openssl/crypto.h>
  86 #include <openssl/buffer.h>
  87 #include <openssl/engine.h>
  88 #ifndef OPENSSL_NO_RSA
  89 #include <openssl/rsa.h>
  90 #endif
  91 #include <openssl/bn.h>
  92
  93 #ifndef OPENSSL_NO_HW
  94 #ifndef OPENSSL_NO_GMP
  95
  96 #include <gmp.h>
  97
  98 #define E_GMP_LIB_NAME "gmp engine"
  99 #include "e_gmp_err.c"
 100
 101 static int e_gmp_destroy(ENGINE *e);
 102 static int e_gmp_init(ENGINE *e);
 103 static int e_gmp_finish(ENGINE *e);
 104 static int e_gmp_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f)(void));
 105
 106 #ifndef OPENSSL_NO_RSA
 107 /* RSA stuff */
 108 static int e_gmp_rsa_mod_exp(BIGNUM *r, const BIGNUM *I, RSA *rsa, BN_CTX *ctx);
 109 static int e_gmp_rsa_finish(RSA *r);
 110 #endif
 111
 112 /* The definitions for control commands specific to this engine */
 113 /* #define E_GMP_CMD_SO_PATH            ENGINE_CMD_BASE */
 114 static const ENGINE_CMD_DEFN e_gmp_cmd_defns[] = {
 115 #if 0
 116         {E_GMP_CMD_SO_PATH,
 117                 "SO_PATH",
 118                 "Specifies the path to the 'e_gmp' shared library",
 119                 ENGINE_CMD_FLAG_STRING},
 120 #endif
 121         {0, NULL, NULL, 0}
 122         };
 123
 124 #ifndef OPENSSL_NO_RSA
 125 /* Our internal RSA_METHOD that we provide pointers to */
 126 static RSA_METHOD e_gmp_rsa =
 127         {
 128         "GMP RSA method",
 129         NULL,
 130         NULL,
 131         NULL,
 132         NULL,
 133         e_gmp_rsa_mod_exp,
 134         NULL,
 135         NULL,
 136         e_gmp_rsa_finish,
 137         /* These flags initialise montgomery crud that GMP ignores, however it
 138          * makes sure the public key ops (which are done in openssl) don't seem
 139          * *slower* than usual :-) */
 140         RSA_FLAG_CACHE_PUBLIC|RSA_FLAG_CACHE_PRIVATE,
 141         NULL,
 142         NULL,
 143         NULL
 144         };
 145 #endif
 146
 147 /* Constants used when creating the ENGINE */
 148 static const char *engine_e_gmp_id = "gmp";
 149 static const char *engine_e_gmp_name = "GMP engine support";
 150
 151 /* This internal function is used by ENGINE_gmp() and possibly by the
 152  * "dynamic" ENGINE support too */
 153 static int bind_helper(ENGINE *e)
 154         {
 155 #ifndef OPENSSL_NO_RSA
 156         const RSA_METHOD *meth1;
 157 #endif
 158         if(!ENGINE_set_id(e, engine_e_gmp_id) ||
 159                         !ENGINE_set_name(e, engine_e_gmp_name) ||
 160 #ifndef OPENSSL_NO_RSA
 161                         !ENGINE_set_RSA(e, &e_gmp_rsa) ||
 162 #endif
 163                         !ENGINE_set_destroy_function(e, e_gmp_destroy) ||
 164                         !ENGINE_set_init_function(e, e_gmp_init) ||
 165                         !ENGINE_set_finish_function(e, e_gmp_finish) ||
 166                         !ENGINE_set_ctrl_function(e, e_gmp_ctrl) ||
 167                         !ENGINE_set_cmd_defns(e, e_gmp_cmd_defns))
 168                 return 0;
 169
 170 #ifndef OPENSSL_NO_RSA
 171         meth1 = RSA_PKCS1_SSLeay();
 172         e_gmp_rsa.rsa_pub_enc = meth1->rsa_pub_enc;
 173         e_gmp_rsa.rsa_pub_dec = meth1->rsa_pub_dec;
 174         e_gmp_rsa.rsa_priv_enc = meth1->rsa_priv_enc;
 175         e_gmp_rsa.rsa_priv_dec = meth1->rsa_priv_dec;
 176         e_gmp_rsa.bn_mod_exp = meth1->bn_mod_exp;
 177 #endif
 178
 179         /* Ensure the e_gmp error handling is set up */
 180         ERR_load_GMP_strings();
 181         return 1;
 182         }
 183
 184 static ENGINE *engine_gmp(void)
 185         {
 186         ENGINE *ret = ENGINE_new();
 187         if(!ret)
 188                 return NULL;
 189         if(!bind_helper(ret))
 190                 {
 191                 ENGINE_free(ret);
 192                 return NULL;
 193                 }
 194         return ret;
 195         }
 196
 197 void ENGINE_load_gmp(void)
 198         {
 199         /* Copied from eng_[openssl|dyn].c */
 200         ENGINE *toadd = engine_gmp();
 201         if(!toadd) return;
 202         ENGINE_add(toadd);
 203         ENGINE_free(toadd);
 204         ERR_clear_error();
 205         }
 206
 207 #ifndef OPENSSL_NO_RSA
 208 /* Used to attach our own key-data to an RSA structure */
 209 static int hndidx_rsa = -1;
 210 #endif
 211
 212 static int e_gmp_destroy(ENGINE *e)
 213         {
 214         ERR_unload_GMP_strings();
 215         return 1;
 216         }
 217
 218 /* (de)initialisation functions. */
 219 static int e_gmp_init(ENGINE *e)
 220         {
 221 #ifndef OPENSSL_NO_RSA
 222         if (hndidx_rsa == -1)
 223                 hndidx_rsa = RSA_get_ex_new_index(0,
 224                         "GMP-based RSA key handle",
 225                         NULL, NULL, NULL);
 226 #endif
 227         if (hndidx_rsa == -1)
 228                 return 0;
 229         return 1;
 230         }
 231
 232 static int e_gmp_finish(ENGINE *e)
 233         {
 234         return 1;
 235         }
 236
 237 static int e_gmp_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f)(void))
 238         {
 239         int to_return = 1;
 240
 241         switch(cmd)
 242                 {
 243 #if 0
 244         case E_GMP_CMD_SO_PATH:
 245                 /* ... */
 246 #endif
 247         /* The command isn't understood by this engine */
 248         default:
 249                 GMPerr(GMP_F_E_GMP_CTRL,
 250                         GMP_R_CTRL_COMMAND_NOT_IMPLEMENTED);
 251                 to_return = 0;
 252                 break;
 253                 }
 254
 255         return to_return;
 256         }
 257
 258
 259 /* Most often limb sizes will be the same. If not, we use hex conversion
 260  * which is neat, but extremely inefficient. */
 261 static int bn2gmp(const BIGNUM *bn, mpz_t g)
 262         {
 263         bn_check_top(bn);
 264         if(((sizeof(bn->d[0]) * 8) == GMP_NUMB_BITS) &&
 265                         (BN_BITS2 == GMP_NUMB_BITS))
 266                 {
 267                 /* The common case */
 268                 if(!_mpz_realloc (g, bn->top))
 269                         return 0;
 270                 memcpy(&g->_mp_d[0], &bn->d[0], bn->top * sizeof(bn->d[0]));
 271                 g->_mp_size = bn->top;
 272                 if(bn->neg)
 273                         g->_mp_size = -g->_mp_size;
 274                 return 1;
 275                 }
 276         else
 277                 {
 278                 int toret;
 279                 char *tmpchar = BN_bn2hex(bn);
 280                 if(!tmpchar) return 0;
 281                 toret = (mpz_set_str(g, tmpchar, 16) == 0 ? 1 : 0);
 282                 OPENSSL_free(tmpchar);
 283                 return toret;
 284                 }
 285         }
 286
 287 static int gmp2bn(mpz_t g, BIGNUM *bn)
 288         {
 289         if(((sizeof(bn->d[0]) * 8) == GMP_NUMB_BITS) &&
 290                         (BN_BITS2 == GMP_NUMB_BITS))
 291                 {
 292                 /* The common case */
 293                 int s = (g->_mp_size >= 0) ? g->_mp_size : -g->_mp_size;
 294                 BN_zero(bn);
 295                 if(bn_expand2 (bn, s) == NULL)
 296                         return 0;
 297                 bn->top = s;
 298                 memcpy(&bn->d[0], &g->_mp_d[0], s * sizeof(bn->d[0]));
 299                 bn_correct_top(bn);
 300                 bn->neg = g->_mp_size >= 0 ? 0 : 1;
 301                 return 1;
 302                 }
 303         else
 304                 {
 305                 int toret;
 306                 char *tmpchar = OPENSSL_malloc(mpz_sizeinbase(g, 16) + 10);
 307                 if(!tmpchar) return 0;
 308                 mpz_get_str(tmpchar, 16, g);
 309                 toret = BN_hex2bn(&bn, tmpchar);
 310                 OPENSSL_free(tmpchar);
 311                 return toret;
 312                 }
 313         }
 314
 315 #ifndef OPENSSL_NO_RSA
 316 typedef struct st_e_gmp_rsa_ctx
 317         {
 318         int public_only;
 319         mpz_t n;
 320         mpz_t d;
 321         mpz_t e;
 322         mpz_t p;
 323         mpz_t q;
 324         mpz_t dmp1;
 325         mpz_t dmq1;
 326         mpz_t iqmp;
 327         mpz_t r0, r1, I0, m1;
 328         } E_GMP_RSA_CTX;
 329
 330 static E_GMP_RSA_CTX *e_gmp_get_rsa(RSA *rsa)
 331         {
 332         E_GMP_RSA_CTX *hptr = RSA_get_ex_data(rsa, hndidx_rsa);
 333         if(hptr) return hptr;
 334         hptr = OPENSSL_malloc(sizeof(E_GMP_RSA_CTX));
 335         if(!hptr) return NULL;
 336         /* These inits could probably be replaced by more intelligent
 337          * mpz_init2() versions, to reduce malloc-thrashing. */
 338         mpz_init(hptr->n);
 339         mpz_init(hptr->d);
 340         mpz_init(hptr->e);
 341         mpz_init(hptr->p);
 342         mpz_init(hptr->q);
 343         mpz_init(hptr->dmp1);
 344         mpz_init(hptr->dmq1);
 345         mpz_init(hptr->iqmp);
 346         mpz_init(hptr->r0);
 347         mpz_init(hptr->r1);
 348         mpz_init(hptr->I0);
 349         mpz_init(hptr->m1);
 350         if(!bn2gmp(rsa->n, hptr->n) || !bn2gmp(rsa->e, hptr->e))
 351                 goto err;
 352         if(!rsa->p || !rsa->q || !rsa->d || !rsa->dmp1 || !rsa->dmq1 || !rsa->iqmp)
 353                 {
 354                 hptr->public_only = 1;
 355                 return hptr;
 356                 }
 357         if(!bn2gmp(rsa->d, hptr->d) || !bn2gmp(rsa->p, hptr->p) ||
 358                         !bn2gmp(rsa->q, hptr->q) || !bn2gmp(rsa->dmp1, hptr->dmp1) ||
 359                         !bn2gmp(rsa->dmq1, hptr->dmq1) || !bn2gmp(rsa->iqmp, hptr->iqmp))
 360                 goto err;
 361         hptr->public_only = 0;
 362         RSA_set_ex_data(rsa, hndidx_rsa, hptr);
 363         return hptr;
 364 err:
 365         mpz_clear(hptr->n);
 366         mpz_clear(hptr->d);
 367         mpz_clear(hptr->e);
 368         mpz_clear(hptr->p);
 369         mpz_clear(hptr->q);
 370         mpz_clear(hptr->dmp1);
 371         mpz_clear(hptr->dmq1);
 372         mpz_clear(hptr->iqmp);
 373         mpz_clear(hptr->r0);
 374         mpz_clear(hptr->r1);
 375         mpz_clear(hptr->I0);
 376         mpz_clear(hptr->m1);
 377         OPENSSL_free(hptr);
 378         return NULL;
 379         }
 380
 381 static int e_gmp_rsa_finish(RSA *rsa)
 382         {
 383         E_GMP_RSA_CTX *hptr = RSA_get_ex_data(rsa, hndidx_rsa);
 384         if(!hptr) return 0;
 385         mpz_clear(hptr->n);
 386         mpz_clear(hptr->d);
 387         mpz_clear(hptr->e);
 388         mpz_clear(hptr->p);
 389         mpz_clear(hptr->q);
 390         mpz_clear(hptr->dmp1);
 391         mpz_clear(hptr->dmq1);
 392         mpz_clear(hptr->iqmp);
 393         mpz_clear(hptr->r0);
 394         mpz_clear(hptr->r1);
 395         mpz_clear(hptr->I0);
 396         mpz_clear(hptr->m1);
 397         OPENSSL_free(hptr);
 398         RSA_set_ex_data(rsa, hndidx_rsa, NULL);
 399         return 1;
 400         }
 401
 402 static int e_gmp_rsa_mod_exp(BIGNUM *r, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)
 403         {
 404         E_GMP_RSA_CTX *hptr;
 405         int to_return = 0;
 406
 407         hptr = e_gmp_get_rsa(rsa);
 408         if(!hptr)
 409                 {
 410                 GMPerr(GMP_F_E_GMP_RSA_MOD_EXP,
 411                                 GMP_R_KEY_CONTEXT_ERROR);
 412                 return 0;
 413                 }
 414         if(hptr->public_only)
 415                 {
 416                 GMPerr(GMP_F_E_GMP_RSA_MOD_EXP,
 417                                 GMP_R_MISSING_KEY_COMPONENTS);
 418                 return 0;
 419                 }
 420
 421         /* ugh!!! */
 422         if(!bn2gmp(I, hptr->I0))
 423                 return 0;
 424
 425         /* This is basically the CRT logic in crypto/rsa/rsa_eay.c reworded into
 426          * GMP-speak. It may be that GMP's API facilitates cleaner formulations
 427          * of this stuff, eg. better handling of negatives, or functions that
 428          * combine operations. */
 429
 430         mpz_mod(hptr->r1, hptr->I0, hptr->q);
 431         mpz_powm(hptr->m1, hptr->r1, hptr->dmq1, hptr->q);
 432
 433         mpz_mod(hptr->r1, hptr->I0, hptr->p);
 434         mpz_powm(hptr->r0, hptr->r1, hptr->dmp1, hptr->p);
 435
 436         mpz_sub(hptr->r0, hptr->r0, hptr->m1);
 437
 438         if(mpz_sgn(hptr->r0) < 0)
 439                 mpz_add(hptr->r0, hptr->r0, hptr->p);
 440         mpz_mul(hptr->r1, hptr->r0, hptr->iqmp);
 441         mpz_mod(hptr->r0, hptr->r1, hptr->p);
 442
 443         if(mpz_sgn(hptr->r0) < 0)
 444                 mpz_add(hptr->r0, hptr->r0, hptr->p);
 445         mpz_mul(hptr->r1, hptr->r0, hptr->q);
 446         mpz_add(hptr->r0, hptr->r1, hptr->m1);
 447
 448         /* ugh!!! */
 449         if(gmp2bn(hptr->r0, r))
 450                 to_return = 1;
 451
 452         return 1;
 453         }
 454 #endif
 455
 456 #endif /* !OPENSSL_NO_GMP */
 457
 458 /* This stuff is needed if this ENGINE is being compiled into a self-contained
 459  * shared-library. */
 460 #ifndef OPENSSL_NO_DYNAMIC_ENGINE
 461 IMPLEMENT_DYNAMIC_CHECK_FN()
 462 #ifndef OPENSSL_NO_GMP
 463 static int bind_fn(ENGINE *e, const char *id)
 464         {
 465         if(id && (strcmp(id, engine_e_gmp_id) != 0))
 466                 return 0;
 467         if(!bind_helper(e))
 468                 return 0;
 469         return 1;
 470         }
 471 IMPLEMENT_DYNAMIC_BIND_FN(bind_fn)
 472 #else
 473 OPENSSL_EXPORT
 474 int bind_engine(ENGINE *e, const char *id, const dynamic_fns *fns);
 475 OPENSSL_EXPORT
 476 int bind_engine(ENGINE *e, const char *id, const dynamic_fns *fns) { return 0; }
 477 #endif
 478 #endif /* !OPENSSL_NO_DYNAMIC_ENGINE */
 479
 480 #endif /* !OPENSSL_NO_HW */