engines/e_atalla.c

   1 /* crypto/engine/hw_atalla.c */
   2 /* Written by Geoff Thorpe (geoff@geoffthorpe.net) for the OpenSSL
   3  * project 2000.
   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 #include <stdio.h>
  60 #include <string.h>
  61 #include <openssl/crypto.h>
  62 #include <openssl/buffer.h>
  63 #include <openssl/dso.h>
  64 #include <openssl/engine.h>
  65 #include <openssl/rsa.h>
  66 #include <openssl/dsa.h>
  67 #include <openssl/dh.h>
  68 #include <openssl/bn.h>
  69
  70 #ifndef OPENSSL_NO_HW
  71 #ifndef OPENSSL_NO_HW_ATALLA
  72
  73 #ifdef FLAT_INC
  74 #include "atalla.h"
  75 #else
  76 #include "vendor_defns/atalla.h"
  77 #endif
  78
  79 #define ATALLA_LIB_NAME "atalla engine"
  80 #include "e_atalla_err.c"
  81
  82 static int atalla_destroy(ENGINE *e);
  83 static int atalla_init(ENGINE *e);
  84 static int atalla_finish(ENGINE *e);
  85 static int atalla_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f)(void));
  86
  87 /* BIGNUM stuff */
  88 static int atalla_mod_exp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
  89                 const BIGNUM *m, BN_CTX *ctx);
  90
  91 #ifndef OPENSSL_NO_RSA
  92 /* RSA stuff */
  93 static int atalla_rsa_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx);
  94 #endif
  95 /* This function is aliased to mod_exp (with the mont stuff dropped). */
  96 static int atalla_mod_exp_mont(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
  97                 const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx);
  98
  99 #ifndef OPENSSL_NO_DSA
 100 /* DSA stuff */
 101 static int atalla_dsa_mod_exp(DSA *dsa, BIGNUM *rr, BIGNUM *a1,
 102                 BIGNUM *p1, BIGNUM *a2, BIGNUM *p2, BIGNUM *m,
 103                 BN_CTX *ctx, BN_MONT_CTX *in_mont);
 104 static int atalla_mod_exp_dsa(DSA *dsa, BIGNUM *r, BIGNUM *a,
 105                 const BIGNUM *p, const BIGNUM *m, BN_CTX *ctx,
 106                 BN_MONT_CTX *m_ctx);
 107 #endif
 108
 109 #ifndef OPENSSL_NO_DH
 110 /* DH stuff */
 111 /* This function is alised to mod_exp (with the DH and mont dropped). */
 112 static int atalla_mod_exp_dh(const DH *dh, BIGNUM *r,
 113                 const BIGNUM *a, const BIGNUM *p,
 114                 const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx);
 115 #endif
 116
 117 /* The definitions for control commands specific to this engine */
 118 #define ATALLA_CMD_SO_PATH              ENGINE_CMD_BASE
 119 static const ENGINE_CMD_DEFN atalla_cmd_defns[] = {
 120         {ATALLA_CMD_SO_PATH,
 121                 "SO_PATH",
 122                 "Specifies the path to the 'atasi' shared library",
 123                 ENGINE_CMD_FLAG_STRING},
 124         {0, NULL, NULL, 0}
 125         };
 126
 127 #ifndef OPENSSL_NO_RSA
 128 /* Our internal RSA_METHOD that we provide pointers to */
 129 static RSA_METHOD atalla_rsa =
 130         {
 131         "Atalla RSA method",
 132         NULL,
 133         NULL,
 134         NULL,
 135         NULL,
 136         atalla_rsa_mod_exp,
 137         atalla_mod_exp_mont,
 138         NULL,
 139         NULL,
 140         0,
 141         NULL,
 142         NULL,
 143         NULL,
 144         NULL
 145         };
 146 #endif
 147
 148 #ifndef OPENSSL_NO_DSA
 149 /* Our internal DSA_METHOD that we provide pointers to */
 150 static DSA_METHOD atalla_dsa =
 151         {
 152         "Atalla DSA method",
 153         NULL, /* dsa_do_sign */
 154         NULL, /* dsa_sign_setup */
 155         NULL, /* dsa_do_verify */
 156         atalla_dsa_mod_exp, /* dsa_mod_exp */
 157         atalla_mod_exp_dsa, /* bn_mod_exp */
 158         NULL, /* init */
 159         NULL, /* finish */
 160         0, /* flags */
 161         NULL, /* app_data */
 162         NULL, /* dsa_paramgen */
 163         NULL /* dsa_keygen */
 164         };
 165 #endif
 166
 167 #ifndef OPENSSL_NO_DH
 168 /* Our internal DH_METHOD that we provide pointers to */
 169 static DH_METHOD atalla_dh =
 170         {
 171         "Atalla DH method",
 172         NULL,
 173         NULL,
 174         atalla_mod_exp_dh,
 175         NULL,
 176         NULL,
 177         0,
 178         NULL,
 179         NULL
 180         };
 181 #endif
 182
 183 /* Constants used when creating the ENGINE */
 184 static const char *engine_atalla_id = "atalla";
 185 static const char *engine_atalla_name = "Atalla hardware engine support";
 186
 187 /* This internal function is used by ENGINE_atalla() and possibly by the
 188  * "dynamic" ENGINE support too */
 189 static int bind_helper(ENGINE *e)
 190         {
 191 #ifndef OPENSSL_NO_RSA
 192         const RSA_METHOD *meth1;
 193 #endif
 194 #ifndef OPENSSL_NO_DSA
 195         const DSA_METHOD *meth2;
 196 #endif
 197 #ifndef OPENSSL_NO_DH
 198         const DH_METHOD *meth3;
 199 #endif
 200         if(!ENGINE_set_id(e, engine_atalla_id) ||
 201                         !ENGINE_set_name(e, engine_atalla_name) ||
 202 #ifndef OPENSSL_NO_RSA
 203                         !ENGINE_set_RSA(e, &atalla_rsa) ||
 204 #endif
 205 #ifndef OPENSSL_NO_DSA
 206                         !ENGINE_set_DSA(e, &atalla_dsa) ||
 207 #endif
 208 #ifndef OPENSSL_NO_DH
 209                         !ENGINE_set_DH(e, &atalla_dh) ||
 210 #endif
 211                         !ENGINE_set_destroy_function(e, atalla_destroy) ||
 212                         !ENGINE_set_init_function(e, atalla_init) ||
 213                         !ENGINE_set_finish_function(e, atalla_finish) ||
 214                         !ENGINE_set_ctrl_function(e, atalla_ctrl) ||
 215                         !ENGINE_set_cmd_defns(e, atalla_cmd_defns))
 216                 return 0;
 217
 218 #ifndef OPENSSL_NO_RSA
 219         /* We know that the "PKCS1_SSLeay()" functions hook properly
 220          * to the atalla-specific mod_exp and mod_exp_crt so we use
 221          * those functions. NB: We don't use ENGINE_openssl() or
 222          * anything "more generic" because something like the RSAref
 223          * code may not hook properly, and if you own one of these
 224          * cards then you have the right to do RSA operations on it
 225          * anyway! */
 226         meth1 = RSA_PKCS1_SSLeay();
 227         atalla_rsa.rsa_pub_enc = meth1->rsa_pub_enc;
 228         atalla_rsa.rsa_pub_dec = meth1->rsa_pub_dec;
 229         atalla_rsa.rsa_priv_enc = meth1->rsa_priv_enc;
 230         atalla_rsa.rsa_priv_dec = meth1->rsa_priv_dec;
 231 #endif
 232
 233 #ifndef OPENSSL_NO_DSA
 234         /* Use the DSA_OpenSSL() method and just hook the mod_exp-ish
 235          * bits. */
 236         meth2 = DSA_OpenSSL();
 237         atalla_dsa.dsa_do_sign = meth2->dsa_do_sign;
 238         atalla_dsa.dsa_sign_setup = meth2->dsa_sign_setup;
 239         atalla_dsa.dsa_do_verify = meth2->dsa_do_verify;
 240 #endif
 241
 242 #ifndef OPENSSL_NO_DH
 243         /* Much the same for Diffie-Hellman */
 244         meth3 = DH_OpenSSL();
 245         atalla_dh.generate_key = meth3->generate_key;
 246         atalla_dh.compute_key = meth3->compute_key;
 247 #endif
 248
 249         /* Ensure the atalla error handling is set up */
 250         ERR_load_ATALLA_strings();
 251         return 1;
 252         }
 253
 254 #ifdef OPENSSL_NO_DYNAMIC_ENGINE
 255 static ENGINE *engine_atalla(void)
 256         {
 257         ENGINE *ret = ENGINE_new();
 258         if(!ret)
 259                 return NULL;
 260         if(!bind_helper(ret))
 261                 {
 262                 ENGINE_free(ret);
 263                 return NULL;
 264                 }
 265         return ret;
 266         }
 267
 268 void ENGINE_load_atalla(void)
 269         {
 270         /* Copied from eng_[openssl|dyn].c */
 271         ENGINE *toadd = engine_atalla();
 272         if(!toadd) return;
 273         ENGINE_add(toadd);
 274         ENGINE_free(toadd);
 275         ERR_clear_error();
 276         }
 277 #endif
 278
 279 /* This is a process-global DSO handle used for loading and unloading
 280  * the Atalla library. NB: This is only set (or unset) during an
 281  * init() or finish() call (reference counts permitting) and they're
 282  * operating with global locks, so this should be thread-safe
 283  * implicitly. */
 284 static DSO *atalla_dso = NULL;
 285
 286 /* These are the function pointers that are (un)set when the library has
 287  * successfully (un)loaded. */
 288 static tfnASI_GetHardwareConfig *p_Atalla_GetHardwareConfig = NULL;
 289 static tfnASI_RSAPrivateKeyOpFn *p_Atalla_RSAPrivateKeyOpFn = NULL;
 290 static tfnASI_GetPerformanceStatistics *p_Atalla_GetPerformanceStatistics = NULL;
 291
 292 /* These are the static string constants for the DSO file name and the function
 293  * symbol names to bind to. Regrettably, the DSO name on *nix appears to be
 294  * "atasi.so" rather than something more consistent like "libatasi.so". At the
 295  * time of writing, I'm not sure what the file name on win32 is but clearly
 296  * native name translation is not possible (eg libatasi.so on *nix, and
 297  * atasi.dll on win32). For the purposes of testing, I have created a symbollic
 298  * link called "libatasi.so" so that we can use native name-translation - a
 299  * better solution will be needed. */
 300 static const char *ATALLA_LIBNAME = NULL;
 301 static const char *get_ATALLA_LIBNAME(void)
 302         {
 303                 if(ATALLA_LIBNAME)
 304                         return ATALLA_LIBNAME;
 305                 return "atasi";
 306         }
 307 static void free_ATALLA_LIBNAME(void)
 308         {
 309                 if(ATALLA_LIBNAME)
 310                         OPENSSL_free((void*)ATALLA_LIBNAME);
 311                 ATALLA_LIBNAME = NULL;
 312         }
 313 static long set_ATALLA_LIBNAME(const char *name)
 314         {
 315         free_ATALLA_LIBNAME();
 316         return (((ATALLA_LIBNAME = BUF_strdup(name)) != NULL) ? 1 : 0);
 317         }
 318 static const char *ATALLA_F1 = "ASI_GetHardwareConfig";
 319 static const char *ATALLA_F2 = "ASI_RSAPrivateKeyOpFn";
 320 static const char *ATALLA_F3 = "ASI_GetPerformanceStatistics";
 321
 322 /* Destructor (complements the "ENGINE_atalla()" constructor) */
 323 static int atalla_destroy(ENGINE *e)
 324         {
 325         free_ATALLA_LIBNAME();
 326         /* Unload the atalla error strings so any error state including our
 327          * functs or reasons won't lead to a segfault (they simply get displayed
 328          * without corresponding string data because none will be found). */
 329         ERR_unload_ATALLA_strings();
 330         return 1;
 331         }
 332
 333 /* (de)initialisation functions. */
 334 static int atalla_init(ENGINE *e)
 335         {
 336         tfnASI_GetHardwareConfig *p1;
 337         tfnASI_RSAPrivateKeyOpFn *p2;
 338         tfnASI_GetPerformanceStatistics *p3;
 339         /* Not sure of the origin of this magic value, but Ben's code had it
 340          * and it seemed to have been working for a few people. :-) */
 341         unsigned int config_buf[1024];
 342
 343         if(atalla_dso != NULL)
 344                 {
 345                 ATALLAerr(ATALLA_F_ATALLA_INIT,ATALLA_R_ALREADY_LOADED);
 346                 goto err;
 347                 }
 348         /* Attempt to load libatasi.so/atasi.dll/whatever. Needs to be
 349          * changed unfortunately because the Atalla drivers don't have
 350          * standard library names that can be platform-translated well. */
 351         /* TODO: Work out how to actually map to the names the Atalla
 352          * drivers really use - for now a symbollic link needs to be
 353          * created on the host system from libatasi.so to atasi.so on
 354          * unix variants. */
 355         atalla_dso = DSO_load(NULL, get_ATALLA_LIBNAME(), NULL, 0);
 356         if(atalla_dso == NULL)
 357                 {
 358                 ATALLAerr(ATALLA_F_ATALLA_INIT,ATALLA_R_NOT_LOADED);
 359                 goto err;
 360                 }
 361         if(!(p1 = (tfnASI_GetHardwareConfig *)DSO_bind_func(
 362                                 atalla_dso, ATALLA_F1)) ||
 363                         !(p2 = (tfnASI_RSAPrivateKeyOpFn *)DSO_bind_func(
 364                                 atalla_dso, ATALLA_F2)) ||
 365                         !(p3 = (tfnASI_GetPerformanceStatistics *)DSO_bind_func(
 366                                 atalla_dso, ATALLA_F3)))
 367                 {
 368                 ATALLAerr(ATALLA_F_ATALLA_INIT,ATALLA_R_NOT_LOADED);
 369                 goto err;
 370                 }
 371         /* Copy the pointers */
 372         p_Atalla_GetHardwareConfig = p1;
 373         p_Atalla_RSAPrivateKeyOpFn = p2;
 374         p_Atalla_GetPerformanceStatistics = p3;
 375         /* Perform a basic test to see if there's actually any unit
 376          * running. */
 377         if(p1(0L, config_buf) != 0)
 378                 {
 379                 ATALLAerr(ATALLA_F_ATALLA_INIT,ATALLA_R_UNIT_FAILURE);
 380                 goto err;
 381                 }
 382         /* Everything's fine. */
 383         return 1;
 384 err:
 385         if(atalla_dso)
 386                 DSO_free(atalla_dso);
 387         p_Atalla_GetHardwareConfig = NULL;
 388         p_Atalla_RSAPrivateKeyOpFn = NULL;
 389         p_Atalla_GetPerformanceStatistics = NULL;
 390         return 0;
 391         }
 392
 393 static int atalla_finish(ENGINE *e)
 394         {
 395         free_ATALLA_LIBNAME();
 396         if(atalla_dso == NULL)
 397                 {
 398                 ATALLAerr(ATALLA_F_ATALLA_FINISH,ATALLA_R_NOT_LOADED);
 399                 return 0;
 400                 }
 401         if(!DSO_free(atalla_dso))
 402                 {
 403                 ATALLAerr(ATALLA_F_ATALLA_FINISH,ATALLA_R_UNIT_FAILURE);
 404                 return 0;
 405                 }
 406         atalla_dso = NULL;
 407         p_Atalla_GetHardwareConfig = NULL;
 408         p_Atalla_RSAPrivateKeyOpFn = NULL;
 409         p_Atalla_GetPerformanceStatistics = NULL;
 410         return 1;
 411         }
 412
 413 static int atalla_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f)(void))
 414         {
 415         int initialised = ((atalla_dso == NULL) ? 0 : 1);
 416         switch(cmd)
 417                 {
 418         case ATALLA_CMD_SO_PATH:
 419                 if(p == NULL)
 420                         {
 421                         ATALLAerr(ATALLA_F_ATALLA_CTRL,ERR_R_PASSED_NULL_PARAMETER);
 422                         return 0;
 423                         }
 424                 if(initialised)
 425                         {
 426                         ATALLAerr(ATALLA_F_ATALLA_CTRL,ATALLA_R_ALREADY_LOADED);
 427                         return 0;
 428                         }
 429                 return set_ATALLA_LIBNAME((const char *)p);
 430         default:
 431                 break;
 432                 }
 433         ATALLAerr(ATALLA_F_ATALLA_CTRL,ATALLA_R_CTRL_COMMAND_NOT_IMPLEMENTED);
 434         return 0;
 435         }
 436
 437 static int atalla_mod_exp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
 438                         const BIGNUM *m, BN_CTX *ctx)
 439         {
 440         /* I need somewhere to store temporary serialised values for
 441          * use with the Atalla API calls. A neat cheat - I'll use
 442          * BIGNUMs from the BN_CTX but access their arrays directly as
 443          * byte arrays <grin>. This way I don't have to clean anything
 444          * up. */
 445         BIGNUM *modulus;
 446         BIGNUM *exponent;
 447         BIGNUM *argument;
 448         BIGNUM *result;
 449         RSAPrivateKey keydata;
 450         int to_return, numbytes;
 451
 452         modulus = exponent = argument = result = NULL;
 453         to_return = 0; /* expect failure */
 454
 455         if(!atalla_dso)
 456                 {
 457                 ATALLAerr(ATALLA_F_ATALLA_MOD_EXP,ATALLA_R_NOT_LOADED);
 458                 goto err;
 459                 }
 460         /* Prepare the params */
 461         BN_CTX_start(ctx);
 462         modulus = BN_CTX_get(ctx);
 463         exponent = BN_CTX_get(ctx);
 464         argument = BN_CTX_get(ctx);
 465         result = BN_CTX_get(ctx);
 466         if (!result)
 467                 {
 468                 ATALLAerr(ATALLA_F_ATALLA_MOD_EXP,ATALLA_R_BN_CTX_FULL);
 469                 goto err;
 470                 }
 471         if(!bn_wexpand(modulus, m->top) || !bn_wexpand(exponent, m->top) ||
 472            !bn_wexpand(argument, m->top) || !bn_wexpand(result, m->top))
 473                 {
 474                 ATALLAerr(ATALLA_F_ATALLA_MOD_EXP,ATALLA_R_BN_EXPAND_FAIL);
 475                 goto err;
 476                 }
 477         /* Prepare the key-data */
 478         memset(&keydata, 0,sizeof keydata);
 479         numbytes = BN_num_bytes(m);
 480         memset(exponent->d, 0, numbytes);
 481         memset(modulus->d, 0, numbytes);
 482         BN_bn2bin(p, (unsigned char *)exponent->d + numbytes - BN_num_bytes(p));
 483         BN_bn2bin(m, (unsigned char *)modulus->d + numbytes - BN_num_bytes(m));
 484         keydata.privateExponent.data = (unsigned char *)exponent->d;
 485         keydata.privateExponent.len = numbytes;
 486         keydata.modulus.data = (unsigned char *)modulus->d;
 487         keydata.modulus.len = numbytes;
 488         /* Prepare the argument */
 489         memset(argument->d, 0, numbytes);
 490         memset(result->d, 0, numbytes);
 491         BN_bn2bin(a, (unsigned char *)argument->d + numbytes - BN_num_bytes(a));
 492         /* Perform the operation */
 493         if(p_Atalla_RSAPrivateKeyOpFn(&keydata, (unsigned char *)result->d,
 494                         (unsigned char *)argument->d,
 495                         keydata.modulus.len) != 0)
 496                 {
 497                 ATALLAerr(ATALLA_F_ATALLA_MOD_EXP,ATALLA_R_REQUEST_FAILED);
 498                 goto err;
 499                 }
 500         /* Convert the response */
 501         BN_bin2bn((unsigned char *)result->d, numbytes, r);
 502         to_return = 1;
 503 err:
 504         BN_CTX_end(ctx);
 505         return to_return;
 506         }
 507
 508 #ifndef OPENSSL_NO_RSA
 509 static int atalla_rsa_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)
 510         {
 511         int to_return = 0;
 512
 513         if(!atalla_dso)
 514                 {
 515                 ATALLAerr(ATALLA_F_ATALLA_RSA_MOD_EXP,ATALLA_R_NOT_LOADED);
 516                 goto err;
 517                 }
 518         if(!rsa->d || !rsa->n)
 519                 {
 520                 ATALLAerr(ATALLA_F_ATALLA_RSA_MOD_EXP,ATALLA_R_MISSING_KEY_COMPONENTS);
 521                 goto err;
 522                 }
 523         to_return = atalla_mod_exp(r0, I, rsa->d, rsa->n, ctx);
 524 err:
 525         return to_return;
 526         }
 527 #endif
 528
 529 #ifndef OPENSSL_NO_DSA
 530 /* This code was liberated and adapted from the commented-out code in
 531  * dsa_ossl.c. Because of the unoptimised form of the Atalla acceleration
 532  * (it doesn't have a CRT form for RSA), this function means that an
 533  * Atalla system running with a DSA server certificate can handshake
 534  * around 5 or 6 times faster/more than an equivalent system running with
 535  * RSA. Just check out the "signs" statistics from the RSA and DSA parts
 536  * of "openssl speed -engine atalla dsa1024 rsa1024". */
 537 static int atalla_dsa_mod_exp(DSA *dsa, BIGNUM *rr, BIGNUM *a1,
 538                 BIGNUM *p1, BIGNUM *a2, BIGNUM *p2, BIGNUM *m,
 539                 BN_CTX *ctx, BN_MONT_CTX *in_mont)
 540         {
 541         BIGNUM t;
 542         int to_return = 0;
 543
 544         BN_init(&t);
 545         /* let rr = a1 ^ p1 mod m */
 546         if (!atalla_mod_exp(rr,a1,p1,m,ctx)) goto end;
 547         /* let t = a2 ^ p2 mod m */
 548         if (!atalla_mod_exp(&t,a2,p2,m,ctx)) goto end;
 549         /* let rr = rr * t mod m */
 550         if (!BN_mod_mul(rr,rr,&t,m,ctx)) goto end;
 551         to_return = 1;
 552 end:
 553         BN_free(&t);
 554         return to_return;
 555         }
 556
 557 static int atalla_mod_exp_dsa(DSA *dsa, BIGNUM *r, BIGNUM *a,
 558                 const BIGNUM *p, const BIGNUM *m, BN_CTX *ctx,
 559                 BN_MONT_CTX *m_ctx)
 560         {
 561         return atalla_mod_exp(r, a, p, m, ctx);
 562         }
 563 #endif
 564
 565 /* This function is aliased to mod_exp (with the mont stuff dropped). */
 566 static int atalla_mod_exp_mont(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
 567                 const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx)
 568         {
 569         return atalla_mod_exp(r, a, p, m, ctx);
 570         }
 571
 572 #ifndef OPENSSL_NO_DH
 573 /* This function is aliased to mod_exp (with the dh and mont dropped). */
 574 static int atalla_mod_exp_dh(const DH *dh, BIGNUM *r,
 575                 const BIGNUM *a, const BIGNUM *p,
 576                 const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx)
 577         {
 578         return atalla_mod_exp(r, a, p, m, ctx);
 579         }
 580 #endif
 581
 582 /* This stuff is needed if this ENGINE is being compiled into a self-contained
 583  * shared-library. */
 584 #ifndef OPENSSL_NO_DYNAMIC_ENGINE
 585 static int bind_fn(ENGINE *e, const char *id)
 586         {
 587         if(id && (strcmp(id, engine_atalla_id) != 0))
 588                 return 0;
 589         if(!bind_helper(e))
 590                 return 0;
 591         return 1;
 592         }
 593 IMPLEMENT_DYNAMIC_CHECK_FN()
 594 IMPLEMENT_DYNAMIC_BIND_FN(bind_fn)
 595 #endif /* OPENSSL_NO_DYNAMIC_ENGINE */
 596
 597 #endif /* !OPENSSL_NO_HW_ATALLA */
 598 #endif /* !OPENSSL_NO_HW */