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 "-DOPENSSL_USE_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:  * "-DOPENSSL_USE_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: 
   89: #ifndef OPENSSL_NO_HW
   90: #if defined(OPENSSL_USE_GMP) && !defined(OPENSSL_NO_HW_GMP)
   91: 
   92: #include <gmp.h>
   93: 
   94: #define E_GMP_LIB_NAME "gmp engine"
   95: #include "e_gmp_err.c"
   96: 
   97: static int e_gmp_destroy(ENGINE *e);
   98: static int e_gmp_init(ENGINE *e);
   99: static int e_gmp_finish(ENGINE *e);
  100: static int e_gmp_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f)(void)); 
  101: 
  102: #ifndef OPENSSL_NO_RSA
  103: /* RSA stuff */
  104: static int e_gmp_rsa_mod_exp(BIGNUM *r, const BIGNUM *I, RSA *rsa, BN_CTX *ctx);
  105: static int e_gmp_rsa_finish(RSA *r);
  106: #endif
  107: 
  108: /* The definitions for control commands specific to this engine */
  109: /* #define E_GMP_CMD_SO_PATH            ENGINE_CMD_BASE */
  110: static const ENGINE_CMD_DEFN e_gmp_cmd_defns[] = {
  111: #if 0
  112:         {E_GMP_CMD_SO_PATH,
  113:                 "SO_PATH",
  114:                 "Specifies the path to the 'e_gmp' shared library",
  115:                 ENGINE_CMD_FLAG_STRING},
  116: #endif
  117:         {0, NULL, NULL, 0}
  118:         };
  119: 
  120: #ifndef OPENSSL_NO_RSA
  121: /* Our internal RSA_METHOD that we provide pointers to */
  122: static RSA_METHOD e_gmp_rsa =
  123:         {
  124:         "GMP RSA method",
  125:         NULL,
  126:         NULL,
  127:         NULL,
  128:         NULL,
  129:         e_gmp_rsa_mod_exp,
  130:         NULL,
  131:         NULL,
  132:         e_gmp_rsa_finish,
  133:         /* These flags initialise montgomery crud that GMP ignores, however it
  134:          * makes sure the public key ops (which are done in openssl) don't seem
  135:          * *slower* than usual :-) */
  136:         RSA_FLAG_CACHE_PUBLIC|RSA_FLAG_CACHE_PRIVATE,
  137:         NULL,
  138:         NULL,
  139:         NULL
  140:         };
  141: #endif
  142: 
  143: /* Constants used when creating the ENGINE */
  144: static const char *engine_e_gmp_id = "gmp";
  145: static const char *engine_e_gmp_name = "GMP engine support";
  146: 
  147: /* This internal function is used by ENGINE_gmp() and possibly by the
  148:  * "dynamic" ENGINE support too */
  149: static int bind_helper(ENGINE *e)
  150:         {
  151: #ifndef OPENSSL_NO_RSA
  152:         const RSA_METHOD *meth1;
  153: #endif
  154:         if(!ENGINE_set_id(e, engine_e_gmp_id) ||
  155:                         !ENGINE_set_name(e, engine_e_gmp_name) ||
  156: #ifndef OPENSSL_NO_RSA
  157:                         !ENGINE_set_RSA(e, &e_gmp_rsa) ||
  158: #endif
  159:                         !ENGINE_set_destroy_function(e, e_gmp_destroy) ||
  160:                         !ENGINE_set_init_function(e, e_gmp_init) ||
  161:                         !ENGINE_set_finish_function(e, e_gmp_finish) ||
  162:                         !ENGINE_set_ctrl_function(e, e_gmp_ctrl) ||
  163:                         !ENGINE_set_cmd_defns(e, e_gmp_cmd_defns))
  164:                 return 0;
  165: 
  166: #ifndef OPENSSL_NO_RSA
  167:         meth1 = RSA_PKCS1_SSLeay();
  168:         e_gmp_rsa.rsa_pub_enc = meth1->rsa_pub_enc;
  169:         e_gmp_rsa.rsa_pub_dec = meth1->rsa_pub_dec;
  170:         e_gmp_rsa.rsa_priv_enc = meth1->rsa_priv_enc;
  171:         e_gmp_rsa.rsa_priv_dec = meth1->rsa_priv_dec;
  172:         e_gmp_rsa.bn_mod_exp = meth1->bn_mod_exp;
  173: #endif
  174: 
  175:         /* Ensure the e_gmp error handling is set up */
  176:         ERR_load_GMP_strings();
  177:         return 1;
  178:         }
  179: 
  180: static ENGINE *engine_gmp(void)
  181:         {
  182:         ENGINE *ret = ENGINE_new();
  183:         if(!ret)
  184:                 return NULL;
  185:         if(!bind_helper(ret))
  186:                 {
  187:                 ENGINE_free(ret);
  188:                 return NULL;
  189:                 }
  190:         return ret;
  191:         }
  192: 
  193: void ENGINE_load_gmp(void)
  194:         {
  195:         /* Copied from eng_[openssl|dyn].c */
  196:         ENGINE *toadd = engine_gmp();
  197:         if(!toadd) return;
  198:         ENGINE_add(toadd);
  199:         ENGINE_free(toadd);
  200:         ERR_clear_error();
  201:         }
  202: 
  203: #ifndef OPENSSL_NO_RSA
  204: /* Used to attach our own key-data to an RSA structure */
  205: static int hndidx_rsa = -1;
  206: #endif
  207: 
  208: static int e_gmp_destroy(ENGINE *e)
  209:         {
  210:         ERR_unload_GMP_strings();
  211:         return 1;
  212:         }
  213: 
  214: /* (de)initialisation functions. */
  215: static int e_gmp_init(ENGINE *e)
  216:         {
  217: #ifndef OPENSSL_NO_RSA
  218:         if (hndidx_rsa == -1)
  219:                 hndidx_rsa = RSA_get_ex_new_index(0,
  220:                         "GMP-based RSA key handle",
  221:                         NULL, NULL, NULL);
  222: #endif
  223:         if (hndidx_rsa == -1)
  224:                 return 0;
  225:         return 1;
  226:         }
  227: 
  228: static int e_gmp_finish(ENGINE *e)
  229:         {
  230:         return 1;
  231:         }
  232: 
  233: static int e_gmp_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f)(void))
  234:         {
  235:         int to_return = 1;
  236: 
  237:         switch(cmd)
  238:                 {
  239: #if 0
  240:         case E_GMP_CMD_SO_PATH:
  241:                 /* ... */
  242: #endif
  243:         /* The command isn't understood by this engine */
  244:         default:
  245:                 GMPerr(GMP_F_E_GMP_CTRL,
  246:                         GMP_R_CTRL_COMMAND_NOT_IMPLEMENTED);
  247:                 to_return = 0;
  248:                 break;
  249:                 }
  250: 
  251:         return to_return;
  252:         }
  253: 
  254: /* HACK - use text I/O functions in openssl and GMP to handle conversions. This
  255:  * is vile. */
  256: static int bn2gmp(const BIGNUM *bn, mpz_t g)
  257:         {
  258:         int toret;
  259:         char *tmpchar = BN_bn2hex(bn);
  260:         if(!tmpchar) return 0;
  261:         toret = (mpz_set_str(g, tmpchar, 16) == 0 ? 1 : 0);
  262:         OPENSSL_free(tmpchar);
  263:         return toret;
  264:         }
  265: 
  266: static int gmp2bn(mpz_t g, BIGNUM *bn)
  267:         {
  268:         int toret;
  269:         char *tmpchar = OPENSSL_malloc(mpz_sizeinbase(g, 16) + 10);
  270:         if(!tmpchar) return 0;
  271:         mpz_get_str(tmpchar, 16, g);
  272:         toret = BN_hex2bn(&bn, tmpchar);
  273:         OPENSSL_free(tmpchar);
  274:         return toret;
  275:         }
  276: 
  277: #ifndef OPENSSL_NO_RSA 
  278: typedef struct st_e_gmp_rsa_ctx
  279:         {
  280:         int public_only;
  281:         mpz_t n;
  282:         mpz_t d;
  283:         mpz_t e;
  284:         mpz_t p;
  285:         mpz_t q;
  286:         mpz_t dmp1;
  287:         mpz_t dmq1;
  288:         mpz_t iqmp;
  289:         mpz_t r0, r1, I0, m1;
  290:         } E_GMP_RSA_CTX;
  291: 
  292: static E_GMP_RSA_CTX *e_gmp_get_rsa(RSA *rsa)
  293:         {
  294:         E_GMP_RSA_CTX *hptr = RSA_get_ex_data(rsa, hndidx_rsa);
  295:         if(hptr) return hptr;
  296:         hptr = OPENSSL_malloc(sizeof(E_GMP_RSA_CTX));
  297:         if(!hptr) return NULL;
  298:         /* These inits could probably be replaced by more intelligent
  299:          * mpz_init2() versions, to reduce malloc-thrashing. */
  300:         mpz_init(hptr->n);
  301:         mpz_init(hptr->d);
  302:         mpz_init(hptr->e);
  303:         mpz_init(hptr->p);
  304:         mpz_init(hptr->q);
  305:         mpz_init(hptr->dmp1);
  306:         mpz_init(hptr->dmq1);
  307:         mpz_init(hptr->iqmp);
  308:         mpz_init(hptr->r0);
  309:         mpz_init(hptr->r1);
  310:         mpz_init(hptr->I0);
  311:         mpz_init(hptr->m1);
  312:         if(!bn2gmp(rsa->n, hptr->n) || !bn2gmp(rsa->e, hptr->e))
  313:                 goto err;
  314:         if(!rsa->p || !rsa->q || !rsa->d || !rsa->dmp1 || !rsa->dmq1 || !rsa->iqmp)
  315:                 {
  316:                 hptr->public_only = 1;
  317:                 return hptr;
  318:                 }
  319:         if(!bn2gmp(rsa->d, hptr->d) || !bn2gmp(rsa->p, hptr->p) ||
  320:                         !bn2gmp(rsa->q, hptr->q) || !bn2gmp(rsa->dmp1, hptr->dmp1) ||
  321:                         !bn2gmp(rsa->dmq1, hptr->dmq1) || !bn2gmp(rsa->iqmp, hptr->iqmp))
  322:                 goto err;
  323:         hptr->public_only = 0;
  324:         RSA_set_ex_data(rsa, hndidx_rsa, hptr);
  325:         return hptr;
  326: err:
  327:         mpz_clear(hptr->n);
  328:         mpz_clear(hptr->d);
  329:         mpz_clear(hptr->e);
  330:         mpz_clear(hptr->p);
  331:         mpz_clear(hptr->q);
  332:         mpz_clear(hptr->dmp1);
  333:         mpz_clear(hptr->dmq1);
  334:         mpz_clear(hptr->iqmp);
  335:         mpz_clear(hptr->r0);
  336:         mpz_clear(hptr->r1);
  337:         mpz_clear(hptr->I0);
  338:         mpz_clear(hptr->m1);
  339:         OPENSSL_free(hptr);
  340:         return NULL;
  341:         }
  342: 
  343: static int e_gmp_rsa_finish(RSA *rsa)
  344:         {
  345:         E_GMP_RSA_CTX *hptr = RSA_get_ex_data(rsa, hndidx_rsa);
  346:         if(!hptr) return 0;
  347:         mpz_clear(hptr->n);
  348:         mpz_clear(hptr->d);
  349:         mpz_clear(hptr->e);
  350:         mpz_clear(hptr->p);
  351:         mpz_clear(hptr->q);
  352:         mpz_clear(hptr->dmp1);
  353:         mpz_clear(hptr->dmq1);
  354:         mpz_clear(hptr->iqmp);
  355:         mpz_clear(hptr->r0);
  356:         mpz_clear(hptr->r1);
  357:         mpz_clear(hptr->I0);
  358:         mpz_clear(hptr->m1);
  359:         OPENSSL_free(hptr);
  360:         RSA_set_ex_data(rsa, hndidx_rsa, NULL);
  361:         return 1;
  362:         }
  363: 
  364: static int e_gmp_rsa_mod_exp(BIGNUM *r, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)
  365:         {
  366:         E_GMP_RSA_CTX *hptr;
  367:         int to_return = 0;
  368: 
  369:         hptr = e_gmp_get_rsa(rsa);
  370:         if(!hptr)
  371:                 {
  372:                 GMPerr(GMP_F_E_GMP_RSA_MOD_EXP,
  373:                                 GMP_R_KEY_CONTEXT_ERROR);
  374:                 return 0;
  375:                 }
  376:         if(hptr->public_only)
  377:                 {
  378:                 GMPerr(GMP_F_E_GMP_RSA_MOD_EXP,
  379:                                 GMP_R_MISSING_KEY_COMPONENTS);
  380:                 return 0;
  381:                 }
  382: 
  383:         /* ugh!!! */
  384:         if(!bn2gmp(I, hptr->I0))
  385:                 return 0;
  386: 
  387:         /* This is basically the CRT logic in crypto/rsa/rsa_eay.c reworded into
  388:          * GMP-speak. It may be that GMP's API facilitates cleaner formulations
  389:          * of this stuff, eg. better handling of negatives, or functions that
  390:          * combine operations. */
  391: 
  392:         mpz_mod(hptr->r1, hptr->I0, hptr->q);
  393:         mpz_powm(hptr->m1, hptr->r1, hptr->dmq1, hptr->q);
  394: 
  395:         mpz_mod(hptr->r1, hptr->I0, hptr->p);
  396:         mpz_powm(hptr->r0, hptr->r1, hptr->dmp1, hptr->p);
  397: 
  398:         mpz_sub(hptr->r0, hptr->r0, hptr->m1);
  399: 
  400:         if(mpz_sgn(hptr->r0) < 0)
  401:                 mpz_add(hptr->r0, hptr->r0, hptr->p);
  402:         mpz_mul(hptr->r1, hptr->r0, hptr->iqmp);
  403:         mpz_mod(hptr->r0, hptr->r1, hptr->p);
  404: 
  405:         if(mpz_sgn(hptr->r0) < 0)
  406:                 mpz_add(hptr->r0, hptr->r0, hptr->p);
  407:         mpz_mul(hptr->r1, hptr->r0, hptr->q);
  408:         mpz_add(hptr->r0, hptr->r1, hptr->m1);
  409: 
  410:         /* ugh!!! */
  411:         if(gmp2bn(hptr->r0, r))
  412:                 to_return = 1;
  413: 
  414:         return 1;
  415:         }
  416: #endif
  417: 
  418: /* This stuff is needed if this ENGINE is being compiled into a self-contained
  419:  * shared-library. */      
  420: #ifdef ENGINE_DYNAMIC_SUPPORT
  421: static int bind_fn(ENGINE *e, const char *id)
  422:         {
  423:         if(id && (strcmp(id, engine_e_gmp_id) != 0))
  424:                 return 0;
  425:         if(!bind_helper(e))
  426:                 return 0;
  427:         return 1;
  428:         }       
  429: IMPLEMENT_DYNAMIC_CHECK_FN()
  430: IMPLEMENT_DYNAMIC_BIND_FN(bind_fn)
  431: #endif /* ENGINE_DYNAMIC_SUPPORT */
  432: 
  433: #endif /* !OPENSSL_NO_HW_GMP */
  434: #endif /* !OPENSSL_NO_HW */
  435: