1: /* crypto/engine/hw_cswift.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: #ifndef OPENSSL_NO_RSA
   66: #include <openssl/rsa.h>
   67: #endif
   68: #ifndef OPENSSL_NO_DSA
   69: #include <openssl/dsa.h>
   70: #endif
   71: #ifndef OPENSSL_NO_DH
   72: #include <openssl/dh.h>
   73: #endif
   74: #include <openssl/rand.h>
   75: #include <openssl/bn.h>
   76: 
   77: #ifndef OPENSSL_NO_HW
   78: #ifndef OPENSSL_NO_HW_CSWIFT
   79: 
   80: /* Attribution notice: Rainbow have generously allowed me to reproduce
   81:  * the necessary definitions here from their API. This means the support
   82:  * can build independently of whether application builders have the
   83:  * API or hardware. This will allow developers to easily produce software
   84:  * that has latent hardware support for any users that have accelerators
   85:  * installed, without the developers themselves needing anything extra.
   86:  *
   87:  * I have only clipped the parts from the CryptoSwift header files that
   88:  * are (or seem) relevant to the CryptoSwift support code. This is
   89:  * simply to keep the file sizes reasonable.
   90:  * [Geoff]
   91:  */
   92: #ifdef FLAT_INC
   93: #include "cswift.h"
   94: #else
   95: #include "vendor_defns/cswift.h"
   96: #endif
   97: 
   98: #define CSWIFT_LIB_NAME "cswift engine"
   99: #include "e_cswift_err.c"
  100: 
  101: #define DECIMAL_SIZE(type)      ((sizeof(type)*8+2)/3+1)
  102: 
  103: static int cswift_destroy(ENGINE *e);
  104: static int cswift_init(ENGINE *e);
  105: static int cswift_finish(ENGINE *e);
  106: static int cswift_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f)(void));
  107: #ifndef OPENSSL_NO_RSA
  108: static int cswift_bn_32copy(SW_LARGENUMBER * out, const BIGNUM * in);
  109: #endif
  110: 
  111: /* BIGNUM stuff */
  112: static int cswift_mod_exp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
  113:                 const BIGNUM *m, BN_CTX *ctx);
  114: #ifndef OPENSSL_NO_RSA
  115: static int cswift_mod_exp_crt(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
  116:                 const BIGNUM *q, const BIGNUM *dmp1, const BIGNUM *dmq1,
  117:                 const BIGNUM *iqmp, BN_CTX *ctx);
  118: #endif
  119: 
  120: #ifndef OPENSSL_NO_RSA
  121: /* RSA stuff */
  122: static int cswift_rsa_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx);
  123: /* This function is aliased to mod_exp (with the mont stuff dropped). */
  124: static int cswift_mod_exp_mont(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
  125:                 const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx);
  126: #endif
  127: 
  128: #ifndef OPENSSL_NO_DSA
  129: /* DSA stuff */
  130: static DSA_SIG *cswift_dsa_sign(const unsigned char *dgst, int dlen, DSA *dsa);
  131: static int cswift_dsa_verify(const unsigned char *dgst, int dgst_len,
  132:                                 DSA_SIG *sig, DSA *dsa);
  133: #endif
  134: 
  135: #ifndef OPENSSL_NO_DH
  136: /* DH stuff */
  137: /* This function is alised to mod_exp (with the DH and mont dropped). */
  138: static int cswift_mod_exp_dh(const DH *dh, BIGNUM *r,
  139:                 const BIGNUM *a, const BIGNUM *p,
  140:                 const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx);
  141: #endif
  142: 
  143: /* RAND stuff */
  144: static int cswift_rand_bytes(unsigned char *buf, int num);
  145: static int cswift_rand_status(void);
  146: 
  147: /* The definitions for control commands specific to this engine */
  148: #define CSWIFT_CMD_SO_PATH              ENGINE_CMD_BASE
  149: static const ENGINE_CMD_DEFN cswift_cmd_defns[] = {
  150:         {CSWIFT_CMD_SO_PATH,
  151:                 "SO_PATH",
  152:                 "Specifies the path to the 'cswift' shared library",
  153:                 ENGINE_CMD_FLAG_STRING},
  154:         {0, NULL, NULL, 0}
  155:         };
  156: 
  157: #ifndef OPENSSL_NO_RSA
  158: /* Our internal RSA_METHOD that we provide pointers to */
  159: static RSA_METHOD cswift_rsa =
  160:         {
  161:         "CryptoSwift RSA method",
  162:         NULL,
  163:         NULL,
  164:         NULL,
  165:         NULL,
  166:         cswift_rsa_mod_exp,
  167:         cswift_mod_exp_mont,
  168:         NULL,
  169:         NULL,
  170:         0,
  171:         NULL,
  172:         NULL,
  173:         NULL,
  174:         NULL
  175:         };
  176: #endif
  177: 
  178: #ifndef OPENSSL_NO_DSA
  179: /* Our internal DSA_METHOD that we provide pointers to */
  180: static DSA_METHOD cswift_dsa =
  181:         {
  182:         "CryptoSwift DSA method",
  183:         cswift_dsa_sign,
  184:         NULL, /* dsa_sign_setup */
  185:         cswift_dsa_verify,
  186:         NULL, /* dsa_mod_exp */
  187:         NULL, /* bn_mod_exp */
  188:         NULL, /* init */
  189:         NULL, /* finish */
  190:         0, /* flags */
  191:         NULL, /* app_data */
  192:         NULL, /* dsa_paramgen */
  193:         NULL /* dsa_keygen */
  194:         };
  195: #endif
  196: 
  197: #ifndef OPENSSL_NO_DH
  198: /* Our internal DH_METHOD that we provide pointers to */
  199: static DH_METHOD cswift_dh =
  200:         {
  201:         "CryptoSwift DH method",
  202:         NULL,
  203:         NULL,
  204:         cswift_mod_exp_dh,
  205:         NULL,
  206:         NULL,
  207:         0,
  208:         NULL,
  209:         NULL
  210:         };
  211: #endif
  212: 
  213: static RAND_METHOD cswift_random =
  214:     {
  215:     /* "CryptoSwift RAND method", */
  216:     NULL,
  217:     cswift_rand_bytes,
  218:     NULL,
  219:     NULL,
  220:     cswift_rand_bytes,
  221:     cswift_rand_status,
  222:     };
  223: 
  224: 
  225: /* Constants used when creating the ENGINE */
  226: static const char *engine_cswift_id = "cswift";
  227: static const char *engine_cswift_name = "CryptoSwift hardware engine support";
  228: 
  229: /* This internal function is used by ENGINE_cswift() and possibly by the
  230:  * "dynamic" ENGINE support too */
  231: static int bind_helper(ENGINE *e)
  232:         {
  233: #ifndef OPENSSL_NO_RSA
  234:         const RSA_METHOD *meth1;
  235: #endif
  236: #ifndef OPENSSL_NO_DH
  237:         const DH_METHOD *meth2;
  238: #endif
  239:         if(!ENGINE_set_id(e, engine_cswift_id) ||
  240:                         !ENGINE_set_name(e, engine_cswift_name) ||
  241: #ifndef OPENSSL_NO_RSA
  242:                         !ENGINE_set_RSA(e, &cswift_rsa) ||
  243: #endif
  244: #ifndef OPENSSL_NO_DSA
  245:                         !ENGINE_set_DSA(e, &cswift_dsa) ||
  246: #endif
  247: #ifndef OPENSSL_NO_DH
  248:                         !ENGINE_set_DH(e, &cswift_dh) ||
  249: #endif
  250:                         !ENGINE_set_RAND(e, &cswift_random) ||
  251:                         !ENGINE_set_destroy_function(e, cswift_destroy) ||
  252:                         !ENGINE_set_init_function(e, cswift_init) ||
  253:                         !ENGINE_set_finish_function(e, cswift_finish) ||
  254:                         !ENGINE_set_ctrl_function(e, cswift_ctrl) ||
  255:                         !ENGINE_set_cmd_defns(e, cswift_cmd_defns))
  256:                 return 0;
  257: 
  258: #ifndef OPENSSL_NO_RSA
  259:         /* We know that the "PKCS1_SSLeay()" functions hook properly
  260:          * to the cswift-specific mod_exp and mod_exp_crt so we use
  261:          * those functions. NB: We don't use ENGINE_openssl() or
  262:          * anything "more generic" because something like the RSAref
  263:          * code may not hook properly, and if you own one of these
  264:          * cards then you have the right to do RSA operations on it
  265:          * anyway! */ 
  266:         meth1 = RSA_PKCS1_SSLeay();
  267:         cswift_rsa.rsa_pub_enc = meth1->rsa_pub_enc;
  268:         cswift_rsa.rsa_pub_dec = meth1->rsa_pub_dec;
  269:         cswift_rsa.rsa_priv_enc = meth1->rsa_priv_enc;
  270:         cswift_rsa.rsa_priv_dec = meth1->rsa_priv_dec;
  271: #endif
  272: 
  273: #ifndef OPENSSL_NO_DH
  274:         /* Much the same for Diffie-Hellman */
  275:         meth2 = DH_OpenSSL();
  276:         cswift_dh.generate_key = meth2->generate_key;
  277:         cswift_dh.compute_key = meth2->compute_key;
  278: #endif
  279: 
  280:         /* Ensure the cswift error handling is set up */
  281:         ERR_load_CSWIFT_strings();
  282:         return 1;
  283:         }
  284: 
  285: #ifdef OPENSSL_NO_DYNAMIC_ENGINE
  286: static ENGINE *engine_cswift(void)
  287:         {
  288:         ENGINE *ret = ENGINE_new();
  289:         if(!ret)
  290:                 return NULL;
  291:         if(!bind_helper(ret))
  292:                 {
  293:                 ENGINE_free(ret);
  294:                 return NULL;
  295:                 }
  296:         return ret;
  297:         }
  298: 
  299: void ENGINE_load_cswift(void)
  300:         {
  301:         /* Copied from eng_[openssl|dyn].c */
  302:         ENGINE *toadd = engine_cswift();
  303:         if(!toadd) return;
  304:         ENGINE_add(toadd);
  305:         ENGINE_free(toadd);
  306:         ERR_clear_error();
  307:         }
  308: #endif
  309: 
  310: /* This is a process-global DSO handle used for loading and unloading
  311:  * the CryptoSwift library. NB: This is only set (or unset) during an
  312:  * init() or finish() call (reference counts permitting) and they're
  313:  * operating with global locks, so this should be thread-safe
  314:  * implicitly. */
  315: static DSO *cswift_dso = NULL;
  316: 
  317: /* These are the function pointers that are (un)set when the library has
  318:  * successfully (un)loaded. */
  319: t_swAcquireAccContext *p_CSwift_AcquireAccContext = NULL;
  320: t_swAttachKeyParam *p_CSwift_AttachKeyParam = NULL;
  321: t_swSimpleRequest *p_CSwift_SimpleRequest = NULL;
  322: t_swReleaseAccContext *p_CSwift_ReleaseAccContext = NULL;
  323: 
  324: /* Used in the DSO operations. */
  325: static const char *CSWIFT_LIBNAME = NULL;
  326: static const char *get_CSWIFT_LIBNAME(void)
  327:         {
  328:         if(CSWIFT_LIBNAME)
  329:                 return CSWIFT_LIBNAME;
  330:         return "swift";
  331:         }
  332: static void free_CSWIFT_LIBNAME(void)
  333:         {
  334:         if(CSWIFT_LIBNAME)
  335:                 OPENSSL_free((void*)CSWIFT_LIBNAME);
  336:         CSWIFT_LIBNAME = NULL;
  337:         }
  338: static long set_CSWIFT_LIBNAME(const char *name)
  339:         {
  340:         free_CSWIFT_LIBNAME();
  341:         return (((CSWIFT_LIBNAME = BUF_strdup(name)) != NULL) ? 1 : 0);
  342:         }
  343: static const char *CSWIFT_F1 = "swAcquireAccContext";
  344: static const char *CSWIFT_F2 = "swAttachKeyParam";
  345: static const char *CSWIFT_F3 = "swSimpleRequest";
  346: static const char *CSWIFT_F4 = "swReleaseAccContext";
  347: 
  348: 
  349: /* CryptoSwift library functions and mechanics - these are used by the
  350:  * higher-level functions further down. NB: As and where there's no
  351:  * error checking, take a look lower down where these functions are
  352:  * called, the checking and error handling is probably down there. */
  353: 
  354: /* utility function to obtain a context */
  355: static int get_context(SW_CONTEXT_HANDLE *hac)
  356:         {
  357:         SW_STATUS status;
  358:  
  359:         status = p_CSwift_AcquireAccContext(hac);
  360:         if(status != SW_OK)
  361:                 return 0;
  362:         return 1;
  363:         }
  364:  
  365: /* similarly to release one. */
  366: static void release_context(SW_CONTEXT_HANDLE hac)
  367:         {
  368:         p_CSwift_ReleaseAccContext(hac);
  369:         }
  370: 
  371: /* Destructor (complements the "ENGINE_cswift()" constructor) */
  372: static int cswift_destroy(ENGINE *e)
  373:         {
  374:         free_CSWIFT_LIBNAME();
  375:         ERR_unload_CSWIFT_strings();
  376:         return 1;
  377:         }
  378: 
  379: /* (de)initialisation functions. */
  380: static int cswift_init(ENGINE *e)
  381:         {
  382:         SW_CONTEXT_HANDLE hac;
  383:         t_swAcquireAccContext *p1;
  384:         t_swAttachKeyParam *p2;
  385:         t_swSimpleRequest *p3;
  386:         t_swReleaseAccContext *p4;
  387: 
  388:         if(cswift_dso != NULL)
  389:                 {
  390:                 CSWIFTerr(CSWIFT_F_CSWIFT_INIT,CSWIFT_R_ALREADY_LOADED);
  391:                 goto err;
  392:                 }
  393:         /* Attempt to load libswift.so/swift.dll/whatever. */
  394:         cswift_dso = DSO_load(NULL, get_CSWIFT_LIBNAME(), NULL, 0);
  395:         if(cswift_dso == NULL)
  396:                 {
  397:                 CSWIFTerr(CSWIFT_F_CSWIFT_INIT,CSWIFT_R_NOT_LOADED);
  398:                 goto err;
  399:                 }
  400:         if(!(p1 = (t_swAcquireAccContext *)
  401:                                 DSO_bind_func(cswift_dso, CSWIFT_F1)) ||
  402:                         !(p2 = (t_swAttachKeyParam *)
  403:                                 DSO_bind_func(cswift_dso, CSWIFT_F2)) ||
  404:                         !(p3 = (t_swSimpleRequest *)
  405:                                 DSO_bind_func(cswift_dso, CSWIFT_F3)) ||
  406:                         !(p4 = (t_swReleaseAccContext *)
  407:                                 DSO_bind_func(cswift_dso, CSWIFT_F4)))
  408:                 {
  409:                 CSWIFTerr(CSWIFT_F_CSWIFT_INIT,CSWIFT_R_NOT_LOADED);
  410:                 goto err;
  411:                 }
  412:         /* Copy the pointers */
  413:         p_CSwift_AcquireAccContext = p1;
  414:         p_CSwift_AttachKeyParam = p2;
  415:         p_CSwift_SimpleRequest = p3;
  416:         p_CSwift_ReleaseAccContext = p4;
  417:         /* Try and get a context - if not, we may have a DSO but no
  418:          * accelerator! */
  419:         if(!get_context(&hac))
  420:                 {
  421:                 CSWIFTerr(CSWIFT_F_CSWIFT_INIT,CSWIFT_R_UNIT_FAILURE);
  422:                 goto err;
  423:                 }
  424:         release_context(hac);
  425:         /* Everything's fine. */
  426:         return 1;
  427: err:
  428:         if(cswift_dso)
  429:         {
  430:                 DSO_free(cswift_dso);
  431:                 cswift_dso = NULL;
  432:         }
  433:         p_CSwift_AcquireAccContext = NULL;
  434:         p_CSwift_AttachKeyParam = NULL;
  435:         p_CSwift_SimpleRequest = NULL;
  436:         p_CSwift_ReleaseAccContext = NULL;
  437:         return 0;
  438:         }
  439: 
  440: static int cswift_finish(ENGINE *e)
  441:         {
  442:         free_CSWIFT_LIBNAME();
  443:         if(cswift_dso == NULL)
  444:                 {
  445:                 CSWIFTerr(CSWIFT_F_CSWIFT_FINISH,CSWIFT_R_NOT_LOADED);
  446:                 return 0;
  447:                 }
  448:         if(!DSO_free(cswift_dso))
  449:                 {
  450:                 CSWIFTerr(CSWIFT_F_CSWIFT_FINISH,CSWIFT_R_UNIT_FAILURE);
  451:                 return 0;
  452:                 }
  453:         cswift_dso = NULL;
  454:         p_CSwift_AcquireAccContext = NULL;
  455:         p_CSwift_AttachKeyParam = NULL;
  456:         p_CSwift_SimpleRequest = NULL;
  457:         p_CSwift_ReleaseAccContext = NULL;
  458:         return 1;
  459:         }
  460: 
  461: static int cswift_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f)(void))
  462:         {
  463:         int initialised = ((cswift_dso == NULL) ? 0 : 1);
  464:         switch(cmd)
  465:                 {
  466:         case CSWIFT_CMD_SO_PATH:
  467:                 if(p == NULL)
  468:                         {
  469:                         CSWIFTerr(CSWIFT_F_CSWIFT_CTRL,ERR_R_PASSED_NULL_PARAMETER);
  470:                         return 0;
  471:                         }
  472:                 if(initialised)
  473:                         {
  474:                         CSWIFTerr(CSWIFT_F_CSWIFT_CTRL,CSWIFT_R_ALREADY_LOADED);
  475:                         return 0;
  476:                         }
  477:                 return set_CSWIFT_LIBNAME((const char *)p);
  478:         default:
  479:                 break;
  480:                 }
  481:         CSWIFTerr(CSWIFT_F_CSWIFT_CTRL,CSWIFT_R_CTRL_COMMAND_NOT_IMPLEMENTED);
  482:         return 0;
  483:         }
  484: 
  485: /* Un petit mod_exp */
  486: static int cswift_mod_exp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
  487:                         const BIGNUM *m, BN_CTX *ctx)
  488:         {
  489:         /* I need somewhere to store temporary serialised values for
  490:          * use with the CryptoSwift API calls. A neat cheat - I'll use
  491:          * BIGNUMs from the BN_CTX but access their arrays directly as
  492:          * byte arrays <grin>. This way I don't have to clean anything
  493:          * up. */
  494:         BIGNUM *modulus;
  495:         BIGNUM *exponent;
  496:         BIGNUM *argument;
  497:         BIGNUM *result;
  498:         SW_STATUS sw_status;
  499:         SW_LARGENUMBER arg, res;
  500:         SW_PARAM sw_param;
  501:         SW_CONTEXT_HANDLE hac;
  502:         int to_return, acquired;
  503:  
  504:         modulus = exponent = argument = result = NULL;
  505:         to_return = 0; /* expect failure */
  506:         acquired = 0;
  507:  
  508:         if(!get_context(&hac))
  509:                 {
  510:                 CSWIFTerr(CSWIFT_F_CSWIFT_MOD_EXP,CSWIFT_R_UNIT_FAILURE);
  511:                 goto err;
  512:                 }
  513:         acquired = 1;
  514:         /* Prepare the params */
  515:         BN_CTX_start(ctx);
  516:         modulus = BN_CTX_get(ctx);
  517:         exponent = BN_CTX_get(ctx);
  518:         argument = BN_CTX_get(ctx);
  519:         result = BN_CTX_get(ctx);
  520:         if(!result)
  521:                 {
  522:                 CSWIFTerr(CSWIFT_F_CSWIFT_MOD_EXP,CSWIFT_R_BN_CTX_FULL);
  523:                 goto err;
  524:                 }
  525:         if(!bn_wexpand(modulus, m->top) || !bn_wexpand(exponent, p->top) ||
  526:                 !bn_wexpand(argument, a->top) || !bn_wexpand(result, m->top))
  527:                 {
  528:                 CSWIFTerr(CSWIFT_F_CSWIFT_MOD_EXP,CSWIFT_R_BN_EXPAND_FAIL);
  529:                 goto err;
  530:                 }
  531:         sw_param.type = SW_ALG_EXP;
  532:         sw_param.up.exp.modulus.nbytes = BN_bn2bin(m,
  533:                 (unsigned char *)modulus->d);
  534:         sw_param.up.exp.modulus.value = (unsigned char *)modulus->d;
  535:         sw_param.up.exp.exponent.nbytes = BN_bn2bin(p,
  536:                 (unsigned char *)exponent->d);
  537:         sw_param.up.exp.exponent.value = (unsigned char *)exponent->d;
  538:         /* Attach the key params */
  539:         sw_status = p_CSwift_AttachKeyParam(hac, &sw_param);
  540:         switch(sw_status)
  541:                 {
  542:         case SW_OK:
  543:                 break;
  544:         case SW_ERR_INPUT_SIZE:
  545:                 CSWIFTerr(CSWIFT_F_CSWIFT_MOD_EXP,CSWIFT_R_BAD_KEY_SIZE);
  546:                 goto err;
  547:         default:
  548:                 {
  549:                 char tmpbuf[DECIMAL_SIZE(sw_status)+1];
  550:                 CSWIFTerr(CSWIFT_F_CSWIFT_MOD_EXP,CSWIFT_R_REQUEST_FAILED);
  551:                 sprintf(tmpbuf, "%ld", sw_status);
  552:                 ERR_add_error_data(2, "CryptoSwift error number is ",tmpbuf);