text: /*-
  *  Written by Corinne Dive-Reclus(cdive@baltimore.com)
  *
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  *
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in
  *    the documentation and/or other materials provided with the
  *    distribution.
  *
  * 3. All advertising materials mentioning features or use of this
  *    software must display the following acknowledgment:
  *    "This product includes software developed by the OpenSSL Project
  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
  *
  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  *    endorse or promote products derived from this software without
  *    prior written permission. For written permission, please contact
  *    licensing@OpenSSL.org.
  *
  * 5. Products derived from this software may not be called "OpenSSL"
  *    nor may "OpenSSL" appear in their names without prior written
  *    permission of the OpenSSL Project.
  *
  * 6. Redistributions of any form whatsoever must retain the following
  *    acknowledgment:
  *    "This product includes software developed by the OpenSSL Project
  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
  *
  * Written by Corinne Dive-Reclus(cdive@baltimore.com)
  *
  * Copyright@2001 Baltimore Technologies Ltd.
  * All right Reserved.
  *                                                                                      *
  *        THIS FILE IS PROVIDED BY BALTIMORE TECHNOLOGIES ``AS IS'' AND                 *
  *        ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE         *
  *        IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE    *
  *        ARE DISCLAIMED.  IN NO EVENT SHALL BALTIMORE TECHNOLOGIES BE LIABLE           *
  *        FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL    *
  *        DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS       *
  *        OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)         *
  *        HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT    *
  *        LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY     *
  *        OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF        *
  *        SUCH DAMAGE.                                                                  *
  ====================================================================*/
  
  #include <stdio.h>
  #include <string.h>
  #include <openssl/crypto.h>
  #include <openssl/pem.h>
  #include <openssl/dso.h>
  #include <openssl/engine.h>
  #include <openssl/rand.h>
  #ifndef OPENSSL_NO_RSA
  # include <openssl/rsa.h>
  #endif
  #ifndef OPENSSL_NO_DSA
  # include <openssl/dsa.h>
  #endif
  #ifndef OPENSSL_NO_DH
  # include <openssl/dh.h>
  #endif
  #include <openssl/bn.h>
  
  #ifndef OPENSSL_NO_HW
  # ifndef OPENSSL_NO_HW_SUREWARE
  
  #  ifdef FLAT_INC
  #   include "sureware.h"
  #  else
  #   include "vendor_defns/sureware.h"
  #  endif
  
  #  define SUREWARE_LIB_NAME "sureware engine"
  #  include "e_sureware_err.c"
  
  static int surewarehk_ctrl(ENGINE *e, int cmd, long i, void *p,
                             void (*f) (void));
  static int surewarehk_destroy(ENGINE *e);
  static int surewarehk_init(ENGINE *e);
  static int surewarehk_finish(ENGINE *e);
  static int surewarehk_modexp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
                               const BIGNUM *m, BN_CTX *ctx);
  
  /* RSA stuff */
  #  ifndef OPENSSL_NO_RSA
  static int surewarehk_rsa_priv_dec(int flen, const unsigned char *from,
                                     unsigned char *to, RSA *rsa, int padding);
  static int surewarehk_rsa_sign(int flen, const unsigned char *from,
                                 unsigned char *to, RSA *rsa, int padding);
  #  endif
  
  /* RAND stuff */
  static int surewarehk_rand_bytes(unsigned char *buf, int num);
  static void surewarehk_rand_seed(const void *buf, int num);
  static void surewarehk_rand_add(const void *buf, int num, double entropy);
  
  /* KM stuff */
  static EVP_PKEY *surewarehk_load_privkey(ENGINE *e, const char *key_id,
                                           UI_METHOD *ui_method,
                                           void *callback_data);
  static EVP_PKEY *surewarehk_load_pubkey(ENGINE *e, const char *key_id,
                                          UI_METHOD *ui_method,
                                          void *callback_data);
  static void surewarehk_ex_free(void *obj, void *item, CRYPTO_EX_DATA *ad,
                                 int idx, long argl, void *argp);
  #  if 0
  static void surewarehk_dh_ex_free(void *obj, void *item, CRYPTO_EX_DATA *ad,
                                    int idx, long argl, void *argp);
  #  endif
  
  #  ifndef OPENSSL_NO_RSA
  /* This function is aliased to mod_exp (with the mont stuff dropped). */
  static int surewarehk_mod_exp_mont(BIGNUM *r, const BIGNUM *a,
                                     const BIGNUM *p, const BIGNUM *m,
                                     BN_CTX *ctx, BN_MONT_CTX *m_ctx)
  {
      return surewarehk_modexp(r, a, p, m, ctx);
  }
  
  /* Our internal RSA_METHOD that we provide pointers to */
  static RSA_METHOD surewarehk_rsa = {
      "SureWare RSA method",
      NULL,                       /* pub_enc */
      NULL,                       /* pub_dec */
      surewarehk_rsa_sign,        /* our rsa_sign is OpenSSL priv_enc */
      surewarehk_rsa_priv_dec,    /* priv_dec */
      NULL,                       /* mod_exp */
      surewarehk_mod_exp_mont,    /* mod_exp_mongomery */
      NULL,                       /* init */
      NULL,                       /* finish */
      0,                          /* RSA flag */
      NULL,
      NULL,                       /* OpenSSL sign */
      NULL,                       /* OpenSSL verify */
      NULL                        /* keygen */
  };
  #  endif
  
  #  ifndef OPENSSL_NO_DH
  /* Our internal DH_METHOD that we provide pointers to */
  /* This function is aliased to mod_exp (with the dh and mont dropped). */
  static int surewarehk_modexp_dh(const DH *dh, BIGNUM *r, const BIGNUM *a,
                                  const BIGNUM *p, const BIGNUM *m, BN_CTX *ctx,
                                  BN_MONT_CTX *m_ctx)
  {
      return surewarehk_modexp(r, a, p, m, ctx);
  }
  
  static DH_METHOD surewarehk_dh = {
      "SureWare DH method",
      NULL,                       /* gen_key */
      NULL,                       /* agree, */
      surewarehk_modexp_dh,       /* dh mod exp */
      NULL,                       /* init */
      NULL,                       /* finish */
      0,                          /* flags */
      NULL,
      NULL
  };
  #  endif
  
  static RAND_METHOD surewarehk_rand = {
      /* "SureWare RAND method", */
      surewarehk_rand_seed,
      surewarehk_rand_bytes,
      NULL,                       /* cleanup */
      surewarehk_rand_add,
      surewarehk_rand_bytes,
      NULL,                       /* rand_status */
  };
  
  #  ifndef OPENSSL_NO_DSA
  /* DSA stuff */
  static DSA_SIG *surewarehk_dsa_do_sign(const unsigned char *dgst, int dlen,
                                         DSA *dsa);
  static int surewarehk_dsa_mod_exp(DSA *dsa, BIGNUM *rr, BIGNUM *a1,
                                    BIGNUM *p1, BIGNUM *a2, BIGNUM *p2,
                                    BIGNUM *m, BN_CTX *ctx,
                                    BN_MONT_CTX *in_mont)
  {
      BIGNUM t;
      int to_return = 0;
      BN_init(&t);
      /* let rr = a1 ^ p1 mod m */
      if (!surewarehk_modexp(rr, a1, p1, m, ctx))
          goto end;
      /* let t = a2 ^ p2 mod m */
      if (!surewarehk_modexp(&t, a2, p2, m, ctx))
          goto end;
      /* let rr = rr * t mod m */
      if (!BN_mod_mul(rr, rr, &t, m, ctx))
          goto end;
      to_return = 1;
   end:
      BN_free(&t);
      return to_return;
  }
  
  static DSA_METHOD surewarehk_dsa = {
      "SureWare DSA method",
      surewarehk_dsa_do_sign,
      NULL,                       /* sign setup */
      NULL,                       /* verify, */
      surewarehk_dsa_mod_exp,     /* mod exp */
      NULL,                       /* bn mod exp */
      NULL,                       /* init */
      NULL,                       /* finish */
      0,
      NULL,
      NULL,
      NULL
  };
  #  endif
  
  static const char *engine_sureware_id = "sureware";
  static const char *engine_sureware_name = "SureWare hardware engine support";
  
  /* Now, to our own code */
  
  /*
   * As this is only ever called once, there's no need for locking (indeed -
   * the lock will already be held by our caller!!!)
   */
  static int bind_sureware(ENGINE *e)
  {
  #  ifndef OPENSSL_NO_RSA
      const RSA_METHOD *meth1;
  #  endif
  #  ifndef OPENSSL_NO_DSA
      const DSA_METHOD *meth2;
  #  endif
  #  ifndef OPENSSL_NO_DH
      const DH_METHOD *meth3;
  #  endif
  
      if (!ENGINE_set_id(e, engine_sureware_id) ||
          !ENGINE_set_name(e, engine_sureware_name) ||
  #  ifndef OPENSSL_NO_RSA
          !ENGINE_set_RSA(e, &surewarehk_rsa) ||
  #  endif
  #  ifndef OPENSSL_NO_DSA
          !ENGINE_set_DSA(e, &surewarehk_dsa) ||
  #  endif
  #  ifndef OPENSSL_NO_DH
          !ENGINE_set_DH(e, &surewarehk_dh) ||
  #  endif
          !ENGINE_set_RAND(e, &surewarehk_rand) ||
          !ENGINE_set_destroy_function(e, surewarehk_destroy) ||
          !ENGINE_set_init_function(e, surewarehk_init) ||
          !ENGINE_set_finish_function(e, surewarehk_finish) ||
          !ENGINE_set_ctrl_function(e, surewarehk_ctrl) ||
          !ENGINE_set_load_privkey_function(e, surewarehk_load_privkey) ||
          !ENGINE_set_load_pubkey_function(e, surewarehk_load_pubkey))
          return 0;
  
  #  ifndef OPENSSL_NO_RSA
      /*
       * We know that the "PKCS1_SSLeay()" functions hook properly to the
       * cswift-specific mod_exp and mod_exp_crt so we use those functions. NB:
       * We don't use ENGINE_openssl() or anything "more generic" because
       * something like the RSAref code may not hook properly, and if you own
       * one of these cards then you have the right to do RSA operations on it
       * anyway!
       */
      meth1 = RSA_PKCS1_SSLeay();
      if (meth1) {
          surewarehk_rsa.rsa_pub_enc = meth1->rsa_pub_enc;
          surewarehk_rsa.rsa_pub_dec = meth1->rsa_pub_dec;
      }
  #  endif
  
  #  ifndef OPENSSL_NO_DSA
      /*
       * Use the DSA_OpenSSL() method and just hook the mod_exp-ish bits.
       */
      meth2 = DSA_OpenSSL();
      if (meth2) {
          surewarehk_dsa.dsa_do_verify = meth2->dsa_do_verify;
      }
  #  endif
  
  #  ifndef OPENSSL_NO_DH
      /* Much the same for Diffie-Hellman */
      meth3 = DH_OpenSSL();
      if (meth3) {
          surewarehk_dh.generate_key = meth3->generate_key;
          surewarehk_dh.compute_key = meth3->compute_key;
      }
  #  endif
  
      /* Ensure the sureware error handling is set up */
      ERR_load_SUREWARE_strings();
      return 1;
  }
  
  #  ifndef OPENSSL_NO_DYNAMIC_ENGINE
  static int bind_helper(ENGINE *e, const char *id)
  {
      if (id && (strcmp(id, engine_sureware_id) != 0))
          return 0;
      if (!bind_sureware(e))
          return 0;
      return 1;
  }
  
  IMPLEMENT_DYNAMIC_CHECK_FN()
      IMPLEMENT_DYNAMIC_BIND_FN(bind_helper)
  #  else
  static ENGINE *engine_sureware(void)
  {
      ENGINE *ret = ENGINE_new();
      if (!ret)
          return NULL;
      if (!bind_sureware(ret)) {
          ENGINE_free(ret);
          return NULL;
      }
      return ret;
  }
  
  void ENGINE_load_sureware(void)
  {
      /* Copied from eng_[openssl|dyn].c */
      ENGINE *toadd = engine_sureware();
      if (!toadd)
          return;
      ENGINE_add(toadd);
      ENGINE_free(toadd);
      ERR_clear_error();
  }
  #  endif
  
  /*
   * This is a process-global DSO handle used for loading and unloading the
   * SureWareHook library. NB: This is only set (or unset) during an init() or
   * finish() call (reference counts permitting) and they're operating with
   * global locks, so this should be thread-safe implicitly.
   */
  static DSO *surewarehk_dso = NULL;
  #  ifndef OPENSSL_NO_RSA
  /* Index for KM handle.  Not really used yet. */
  static int rsaHndidx = -1;
  #  endif
  #  ifndef OPENSSL_NO_DSA
  /* Index for KM handle.  Not really used yet. */
  static int dsaHndidx = -1;
  #  endif
  
  /*
   * These are the function pointers that are (un)set when the library has
   * successfully (un)loaded.
   */
  static SureWareHook_Init_t *p_surewarehk_Init = NULL;
  static SureWareHook_Finish_t *p_surewarehk_Finish = NULL;
  static SureWareHook_Rand_Bytes_t *p_surewarehk_Rand_Bytes = NULL;
  static SureWareHook_Rand_Seed_t *p_surewarehk_Rand_Seed = NULL;
  static SureWareHook_Load_Privkey_t *p_surewarehk_Load_Privkey = NULL;
  static SureWareHook_Info_Pubkey_t *p_surewarehk_Info_Pubkey = NULL;
  static SureWareHook_Load_Rsa_Pubkey_t *p_surewarehk_Load_Rsa_Pubkey = NULL;
  static SureWareHook_Load_Dsa_Pubkey_t *p_surewarehk_Load_Dsa_Pubkey = NULL;
  static SureWareHook_Free_t *p_surewarehk_Free = NULL;
  static SureWareHook_Rsa_Priv_Dec_t *p_surewarehk_Rsa_Priv_Dec = NULL;
  static SureWareHook_Rsa_Sign_t *p_surewarehk_Rsa_Sign = NULL;
  static SureWareHook_Dsa_Sign_t *p_surewarehk_Dsa_Sign = NULL;
  static SureWareHook_Mod_Exp_t *p_surewarehk_Mod_Exp = NULL;
  
  /* Used in the DSO operations. */
  static const char *surewarehk_LIBNAME = "SureWareHook";
  static const char *n_surewarehk_Init = "SureWareHook_Init";
  static const char *n_surewarehk_Finish = "SureWareHook_Finish";
  static const char *n_surewarehk_Rand_Bytes = "SureWareHook_Rand_Bytes";
  static const char *n_surewarehk_Rand_Seed = "SureWareHook_Rand_Seed";
  static const char *n_surewarehk_Load_Privkey = "SureWareHook_Load_Privkey";
  static const char *n_surewarehk_Info_Pubkey = "SureWareHook_Info_Pubkey";
  static const char *n_surewarehk_Load_Rsa_Pubkey =
      "SureWareHook_Load_Rsa_Pubkey";
  static const char *n_surewarehk_Load_Dsa_Pubkey =
      "SureWareHook_Load_Dsa_Pubkey";
  static const char *n_surewarehk_Free = "SureWareHook_Free";
  static const char *n_surewarehk_Rsa_Priv_Dec = "SureWareHook_Rsa_Priv_Dec";
  static const char *n_surewarehk_Rsa_Sign = "SureWareHook_Rsa_Sign";
  static const char *n_surewarehk_Dsa_Sign = "SureWareHook_Dsa_Sign";
  static const char *n_surewarehk_Mod_Exp = "SureWareHook_Mod_Exp";
  static BIO *logstream = NULL;
  
  /*
   * SureWareHook library functions and mechanics - these are used by the
   * higher-level functions further down. NB: As and where there's no error
   * checking, take a look lower down where these functions are called, the
   * checking and error handling is probably down there.
   */
  static int threadsafe = 1;
  static int surewarehk_ctrl(ENGINE *e, int cmd, long i, void *p,
                             void (*f) (void))
  {
      int to_return = 1;
  
      switch (cmd) {
      case ENGINE_CTRL_SET_LOGSTREAM:
          {
              BIO *bio = (BIO *)p;
              CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
              if (logstream) {
                  BIO_free(logstream);
                  logstream = NULL;
              }
              if (CRYPTO_add(&bio->references, 1, CRYPTO_LOCK_BIO) > 1)
                  logstream = bio;
              else
                  SUREWAREerr(SUREWARE_F_SUREWAREHK_CTRL,
                              SUREWARE_R_BIO_WAS_FREED);
          }
          CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
          break;
          /*
           * This will prevent the initialisation function from "installing"
           * the mutex-handling callbacks, even if they are available from
           * within the library (or were provided to the library from the
           * calling application). This is to remove any baggage for
           * applications not using multithreading.
           */
      case ENGINE_CTRL_CHIL_NO_LOCKING:
          CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
          threadsafe = 0;
          CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
          break;
  
          /* The command isn't understood by this engine */
      default:
          SUREWAREerr(SUREWARE_F_SUREWAREHK_CTRL,
                      ENGINE_R_CTRL_COMMAND_NOT_IMPLEMENTED);
          to_return = 0;
          break;
      }
  
      return to_return;
  }
  
  /* Destructor (complements the "ENGINE_surewarehk()" constructor) */
  static int surewarehk_destroy(ENGINE *e)
  {
      ERR_unload_SUREWARE_strings();
      return 1;
  }
  
  /* (de)initialisation functions. */
  static int surewarehk_init(ENGINE *e)
  {
      char msg[64] = "ENGINE_init";
      SureWareHook_Init_t *p1 = NULL;
      SureWareHook_Finish_t *p2 = NULL;
      SureWareHook_Rand_Bytes_t *p3 = NULL;
      SureWareHook_Rand_Seed_t *p4 = NULL;
      SureWareHook_Load_Privkey_t *p5 = NULL;
      SureWareHook_Load_Rsa_Pubkey_t *p6 = NULL;
      SureWareHook_Free_t *p7 = NULL;
      SureWareHook_Rsa_Priv_Dec_t *p8 = NULL;
      SureWareHook_Rsa_Sign_t *p9 = NULL;
      SureWareHook_Dsa_Sign_t *p12 = NULL;
      SureWareHook_Info_Pubkey_t *p13 = NULL;
      SureWareHook_Load_Dsa_Pubkey_t *p14 = NULL;
      SureWareHook_Mod_Exp_t *p15 = NULL;
  
      if (surewarehk_dso != NULL) {
          SUREWAREerr(SUREWARE_F_SUREWAREHK_INIT, ENGINE_R_ALREADY_LOADED);
          goto err;
      }
      /* Attempt to load libsurewarehk.so/surewarehk.dll/whatever. */
      surewarehk_dso = DSO_load(NULL, surewarehk_LIBNAME, NULL, 0);
      if (surewarehk_dso == NULL) {
          SUREWAREerr(SUREWARE_F_SUREWAREHK_INIT, ENGINE_R_DSO_FAILURE);
          goto err;
      }
      if (!
          (p1 =
           (SureWareHook_Init_t *) DSO_bind_func(surewarehk_dso,
                                                 n_surewarehk_Init))
  || !(p2 =
       (SureWareHook_Finish_t *) DSO_bind_func(surewarehk_dso,
                                               n_surewarehk_Finish))
  || !(p3 =
       (SureWareHook_Rand_Bytes_t *) DSO_bind_func(surewarehk_dso,
                                                   n_surewarehk_Rand_Bytes))
  || !(p4 =
       (SureWareHook_Rand_Seed_t *) DSO_bind_func(surewarehk_dso,
                                                  n_surewarehk_Rand_Seed))
  || !(p5 =
       (SureWareHook_Load_Privkey_t *) DSO_bind_func(surewarehk_dso,
                                                     n_surewarehk_Load_Privkey))
  || !(p6 =
       (SureWareHook_Load_Rsa_Pubkey_t *) DSO_bind_func(surewarehk_dso,
                                                        n_surewarehk_Load_Rsa_Pubkey))
  || !(p7 =
       (SureWareHook_Free_t *) DSO_bind_func(surewarehk_dso, n_surewarehk_Free))
  || !(p8 =
       (SureWareHook_Rsa_Priv_Dec_t *) DSO_bind_func(surewarehk_dso,
                                                     n_surewarehk_Rsa_Priv_Dec))
  || !(p9 =
       (SureWareHook_Rsa_Sign_t *) DSO_bind_func(surewarehk_dso,
                                                 n_surewarehk_Rsa_Sign))
  || !(p12 =
       (SureWareHook_Dsa_Sign_t *) DSO_bind_func(surewarehk_dso,
                                                 n_surewarehk_Dsa_Sign))
  || !(p13 =
       (SureWareHook_Info_Pubkey_t *) DSO_bind_func(surewarehk_dso,
                                                    n_surewarehk_Info_Pubkey))
  || !(p14 =
       (SureWareHook_Load_Dsa_Pubkey_t *) DSO_bind_func(surewarehk_dso,
                                                        n_surewarehk_Load_Dsa_Pubkey))
  || !(p15 =
       (SureWareHook_Mod_Exp_t *) DSO_bind_func(surewarehk_dso,
                                                n_surewarehk_Mod_Exp))) {
          SUREWAREerr(SUREWARE_F_SUREWAREHK_INIT, ENGINE_R_DSO_FAILURE);
          goto err;
      }
      /* Copy the pointers */
      p_surewarehk_Init = p1;
      p_surewarehk_Finish = p2;
      p_surewarehk_Rand_Bytes = p3;
      p_surewarehk_Rand_Seed = p4;
      p_surewarehk_Load_Privkey = p5;
      p_surewarehk_Load_Rsa_Pubkey = p6;
      p_surewarehk_Free = p7;
      p_surewarehk_Rsa_Priv_Dec = p8;
      p_surewarehk_Rsa_Sign = p9;
      p_surewarehk_Dsa_Sign = p12;
      p_surewarehk_Info_Pubkey = p13;
      p_surewarehk_Load_Dsa_Pubkey = p14;
      p_surewarehk_Mod_Exp = p15;
      /* Contact the hardware and initialises it. */
      if (p_surewarehk_Init(msg, threadsafe) == SUREWAREHOOK_ERROR_UNIT_FAILURE) {
          SUREWAREerr(SUREWARE_F_SUREWAREHK_INIT, SUREWARE_R_UNIT_FAILURE);
          goto err;
      }
      if (p_surewarehk_Init(msg, threadsafe) == SUREWAREHOOK_ERROR_UNIT_FAILURE) {
          SUREWAREerr(SUREWARE_F_SUREWAREHK_INIT, SUREWARE_R_UNIT_FAILURE);
          goto err;
      }
      /*
       * try to load the default private key, if failed does not return a
       * failure but wait for an explicit ENGINE_load_privakey
       */
      surewarehk_load_privkey(e, NULL, NULL, NULL);
  
      /* Everything's fine. */
  #  ifndef OPENSSL_NO_RSA
      if (rsaHndidx == -1)
          rsaHndidx = RSA_get_ex_new_index(0,
                                           "SureWareHook RSA key handle",
                                           NULL, NULL, surewarehk_ex_free);
  #  endif
  #  ifndef OPENSSL_NO_DSA
      if (dsaHndidx == -1)
          dsaHndidx = DSA_get_ex_new_index(0,
                                           "SureWareHook DSA key handle",
                                           NULL, NULL, surewarehk_ex_free);
  #  endif
  
      return 1;
   err:
      if (surewarehk_dso)
          DSO_free(surewarehk_dso);
      surewarehk_dso = NULL;
      p_surewarehk_Init = NULL;
      p_surewarehk_Finish = NULL;
      p_surewarehk_Rand_Bytes = NULL;
      p_surewarehk_Rand_Seed = NULL;
      p_surewarehk_Load_Privkey = NULL;
      p_surewarehk_Load_Rsa_Pubkey = NULL;
      p_surewarehk_Free = NULL;
      p_surewarehk_Rsa_Priv_Dec = NULL;
      p_surewarehk_Rsa_Sign = NULL;
      p_surewarehk_Dsa_Sign = NULL;
      p_surewarehk_Info_Pubkey = NULL;
      p_surewarehk_Load_Dsa_Pubkey = NULL;
      p_surewarehk_Mod_Exp = NULL;
      return 0;
  }
  
  static int surewarehk_finish(ENGINE *e)
  {
      int to_return = 1;
      if (surewarehk_dso == NULL) {
          SUREWAREerr(SUREWARE_F_SUREWAREHK_FINISH, ENGINE_R_NOT_LOADED);
          to_return = 0;
          goto err;
      }
      p_surewarehk_Finish();
      if (!DSO_free(surewarehk_dso)) {
          SUREWAREerr(SUREWARE_F_SUREWAREHK_FINISH, ENGINE_R_DSO_FAILURE);
          to_return = 0;
          goto err;
      }
   err:
      if (logstream)
          BIO_free(logstream);
      surewarehk_dso = NULL;
      p_surewarehk_Init = NULL;
      p_surewarehk_Finish = NULL;
      p_surewarehk_Rand_Bytes = NULL;
      p_surewarehk_Rand_Seed = NULL;
      p_surewarehk_Load_Privkey = NULL;
      p_surewarehk_Load_Rsa_Pubkey = NULL;
      p_surewarehk_Free = NULL;
      p_surewarehk_Rsa_Priv_Dec = NULL;
      p_surewarehk_Rsa_Sign = NULL;
      p_surewarehk_Dsa_Sign = NULL;
      p_surewarehk_Info_Pubkey = NULL;
      p_surewarehk_Load_Dsa_Pubkey = NULL;
      p_surewarehk_Mod_Exp = NULL;
      return to_return;
  }
  
  static void surewarehk_error_handling(char *const msg, int func, int ret)
  {
      switch (ret) {
      case SUREWAREHOOK_ERROR_UNIT_FAILURE:
          ENGINEerr(func, SUREWARE_R_UNIT_FAILURE);
          break;
      case SUREWAREHOOK_ERROR_FALLBACK:
          ENGINEerr(func, SUREWARE_R_REQUEST_FALLBACK);
          break;
      case SUREWAREHOOK_ERROR_DATA_SIZE:
          ENGINEerr(func, SUREWARE_R_SIZE_TOO_LARGE_OR_TOO_SMALL);
          break;
      case SUREWAREHOOK_ERROR_INVALID_PAD:
          ENGINEerr(func, SUREWARE_R_PADDING_CHECK_FAILED);
          break;
      default:
          ENGINEerr(func, SUREWARE_R_REQUEST_FAILED);
          break;
      case 1:                    /* nothing */
          msg[0] = '\0';
      }
      if (*msg) {
          ERR_add_error_data(1, msg);
          if (logstream) {
              CRYPTO_w_lock(CRYPTO_LOCK_BIO);
              BIO_write(logstream, msg, strlen(msg));
              CRYPTO_w_unlock(CRYPTO_LOCK_BIO);
          }
      }
  }
  
  static int surewarehk_rand_bytes(unsigned char *buf, int num)
  {
      int ret = 0;
      char msg[64] = "ENGINE_rand_bytes";
      if (!p_surewarehk_Rand_Bytes) {
          SUREWAREerr(SUREWARE_F_SUREWAREHK_RAND_BYTES,
                      ENGINE_R_NOT_INITIALISED);
      } else {
          ret = p_surewarehk_Rand_Bytes(msg, buf, num);
          surewarehk_error_handling(msg, SUREWARE_F_SUREWAREHK_RAND_BYTES, ret);
      }
      return ret == 1 ? 1 : 0;
  }
  
  static void surewarehk_rand_seed(const void *buf, int num)
  {
      int ret = 0;
      char msg[64] = "ENGINE_rand_seed";
      if (!p_surewarehk_Rand_Seed) {
          SUREWAREerr(SUREWARE_F_SUREWAREHK_RAND_SEED,
                      ENGINE_R_NOT_INITIALISED);
      } else {
          ret = p_surewarehk_Rand_Seed(msg, buf, num);
          surewarehk_error_handling(msg, SUREWARE_F_SUREWAREHK_RAND_SEED, ret);
      }
  }
  
  static void surewarehk_rand_add(const void *buf, int num, double entropy)
  {
      surewarehk_rand_seed(buf, num);
  }
  
  static EVP_PKEY *sureware_load_public(ENGINE *e, const char *key_id,
                                        char *hptr, unsigned long el,
                                        char keytype)
  {
      EVP_PKEY *res = NULL;
  #  ifndef OPENSSL_NO_RSA
      RSA *rsatmp = NULL;
  #  endif
  #  ifndef OPENSSL_NO_DSA
      DSA *dsatmp = NULL;
  #  endif
      char msg[64] = "sureware_load_public";
      int ret = 0;
      if (!p_surewarehk_Load_Rsa_Pubkey || !p_surewarehk_Load_Dsa_Pubkey) {
          SUREWAREerr(SUREWARE_F_SUREWARE_LOAD_PUBLIC,
                      ENGINE_R_NOT_INITIALISED);
          goto err;
      }
      switch (keytype) {
  #  ifndef OPENSSL_NO_RSA
      case 1:
           /*RSA*/
              /* set private external reference */
              rsatmp = RSA_new_method(e);
          RSA_set_ex_data(rsatmp, rsaHndidx, hptr);
          rsatmp->flags |= RSA_FLAG_EXT_PKEY;
  
          /* set public big nums */
          rsatmp->e = BN_new();
          rsatmp->n = BN_new();
          bn_expand2(rsatmp->e, el / sizeof(BN_ULONG));
          bn_expand2(rsatmp->n, el / sizeof(BN_ULONG));
          if (!rsatmp->e || rsatmp->e->dmax != (int)(el / sizeof(BN_ULONG)) ||
              !rsatmp->n || rsatmp->n->dmax != (int)(el / sizeof(BN_ULONG)))
              goto err;
          ret = p_surewarehk_Load_Rsa_Pubkey(msg, key_id, el,
                                             (unsigned long *)rsatmp->n->d,
                                             (unsigned long *)rsatmp->e->d);
          surewarehk_error_handling(msg, SUREWARE_F_SUREWARE_LOAD_PUBLIC, ret);
          if (ret != 1) {
              SUREWAREerr(SUREWARE_F_SUREWARE_LOAD_PUBLIC,
                          ENGINE_R_FAILED_LOADING_PUBLIC_KEY);
              goto err;
          }
          /* normalise pub e and pub n */
          rsatmp->e->top = el / sizeof(BN_ULONG);
          bn_fix_top(rsatmp->e);
          rsatmp->n->top = el / sizeof(BN_ULONG);
          bn_fix_top(rsatmp->n);
          /* create an EVP object: engine + rsa key */
          res = EVP_PKEY_new();
          EVP_PKEY_assign_RSA(res, rsatmp);
          break;
  #  endif
  
  #  ifndef OPENSSL_NO_DSA
      case 2:
           /*DSA*/
              /* set private/public external reference */
              dsatmp = DSA_new_method(e);
          DSA_set_ex_data(dsatmp, dsaHndidx, hptr);
          /*
           * dsatmp->flags |= DSA_FLAG_EXT_PKEY;
           */
  
          /* set public key */
          dsatmp->pub_key = BN_new();
          dsatmp->p = BN_new();
          dsatmp->q = BN_new();
          dsatmp->g = BN_new();
          bn_expand2(dsatmp->pub_key, el / sizeof(BN_ULONG));
          bn_expand2(dsatmp->p, el / sizeof(BN_ULONG));
          bn_expand2(dsatmp->q, 20 / sizeof(BN_ULONG));
          bn_expand2(dsatmp->g, el / sizeof(BN_ULONG));
          if (!dsatmp->pub_key
              || dsatmp->pub_key->dmax != (int)(el / sizeof(BN_ULONG))
              || !dsatmp->p || dsatmp->p->dmax != (int)(el / sizeof(BN_ULONG))
              || !dsatmp->q || dsatmp->q->dmax != 20 / sizeof(BN_ULONG)
              || !dsatmp->g || dsatmp->g->dmax != (int)(el / sizeof(BN_ULONG)))
              goto err;
  
          ret = p_surewarehk_Load_Dsa_Pubkey(msg, key_id, el,
                                             (unsigned long *)dsatmp->
                                             pub_key->d,
                                             (unsigned long *)dsatmp->p->d,
                                             (unsigned long *)dsatmp->q->d,
                                             (unsigned long *)dsatmp->g->d);
          surewarehk_error_handling(msg, SUREWARE_F_SUREWARE_LOAD_PUBLIC, ret);
          if (ret != 1) {
              SUREWAREerr(SUREWARE_F_SUREWARE_LOAD_PUBLIC,
                          ENGINE_R_FAILED_LOADING_PUBLIC_KEY);
              goto err;
          }
          /* set parameters */
          /* normalise pubkey and parameters in case of */
          dsatmp->pub_key->top = el / sizeof(BN_ULONG);
          bn_fix_top(dsatmp->pub_key);
          dsatmp->p->top = el / sizeof(BN_ULONG);
          bn_fix_top(dsatmp->p);
          dsatmp->q->top = 20 / sizeof(BN_ULONG);
          bn_fix_top(dsatmp->q);
          dsatmp->g->top = el / sizeof(BN_ULONG);
          bn_fix_top(dsatmp->g);
  
          /* create an EVP object: engine + rsa key */
          res = EVP_PKEY_new();
          EVP_PKEY_assign_DSA(res, dsatmp);
          break;
  #  endif
  
      default:
          SUREWAREerr(SUREWARE_F_SUREWARE_LOAD_PUBLIC,
                      ENGINE_R_FAILED_LOADING_PRIVATE_KEY);
          goto err;
      }
      return res;
   err:
      if (res)
          EVP_PKEY_free(res);
  #  ifndef OPENSSL_NO_RSA
      if (rsatmp)
          RSA_free(rsatmp);
  #  endif
  #  ifndef OPENSSL_NO_DSA
      if (dsatmp)
          DSA_free(dsatmp);
  #  endif
      return NULL;
  }
  
  static EVP_PKEY *surewarehk_load_privkey(ENGINE *e, const char *key_id,
                                           UI_METHOD *ui_method,
                                           void *callback_data)
  {
      EVP_PKEY *res = NULL;
      int ret = 0;
      unsigned long el = 0;
      char *hptr = NULL;
      char keytype = 0;
      char msg[64] = "ENGINE_load_privkey";
  
      if (!p_surewarehk_Load_Privkey) {
          SUREWAREerr(SUREWARE_F_SUREWAREHK_LOAD_PRIVKEY,
                      ENGINE_R_NOT_INITIALISED);
      } else {
          ret = p_surewarehk_Load_Privkey(msg, key_id, &hptr, &el, &keytype);
          if (ret != 1) {
              SUREWAREerr(SUREWARE_F_SUREWAREHK_LOAD_PRIVKEY,
                          ENGINE_R_FAILED_LOADING_PRIVATE_KEY);
              ERR_add_error_data(1, msg);
          } else
              res = sureware_load_public(e, key_id, hptr, el, keytype);
      }
      return res;
  }
  
  static EVP_PKEY *surewarehk_load_pubkey(ENGINE *e, const char *key_id,
                                          UI_METHOD *ui_method,
                                          void *callback_data)
  {
      EVP_PKEY *res = NULL;
      int ret = 0;
      unsigned long el = 0;
      char *hptr = NULL;
      char keytype = 0;
      char msg[64] = "ENGINE_load_pubkey";
  
      if (!p_surewarehk_Info_Pubkey) {
          SUREWAREerr(SUREWARE_F_SUREWAREHK_LOAD_PUBKEY,
                      ENGINE_R_NOT_INITIALISED);
      } else {
          /* call once to identify if DSA or RSA */
          ret = p_surewarehk_Info_Pubkey(msg, key_id, &el, &keytype);
          if (ret != 1) {
              SUREWAREerr(SUREWARE_F_SUREWAREHK_LOAD_PUBKEY,
                          ENGINE_R_FAILED_LOADING_PUBLIC_KEY);
              ERR_add_error_data(1, msg);
          } else
              res = sureware_load_public(e, key_id, hptr, el, keytype);
      }
      return res;
  }
  
  /*
   * This cleans up an RSA/DSA KM key(do not destroy the key into the hardware)
   * , called when ex_data is freed
   */
  static void surewarehk_ex_free(void *obj, void *item, CRYPTO_EX_DATA *ad,
                                 int idx, long argl, void *argp)
  {
      if (!p_surewarehk_Free) {
          SUREWAREerr(SUREWARE_F_SUREWAREHK_EX_FREE, ENGINE_R_NOT_INITIALISED);
      } else
          p_surewarehk_Free((char *)item, 0);
  }
  
  #  if 0
  /* not currently used (bug?) */
  /*
   * This cleans up an DH KM key (destroys the key into hardware), called when
   * ex_data is freed
   */
  static void surewarehk_dh_ex_free(void *obj, void *item, CRYPTO_EX_DATA *ad,
                                    int idx, long argl, void *argp)
  {
      if (!p_surewarehk_Free) {
          SUREWAREerr(SUREWARE_F_SUREWAREHK_DH_EX_FREE,
                      ENGINE_R_NOT_INITIALISED);
      } else
          p_surewarehk_Free((char *)item, 1);
  }
  #  endif
  
  /*
   * return number of decrypted bytes
   */
  #  ifndef OPENSSL_NO_RSA
  static int surewarehk_rsa_priv_dec(int flen, const unsigned char *from,
                                     unsigned char *to, RSA *rsa, int padding)
  {
      int ret = 0, tlen;
      char *buf = NULL, *hptr = NULL;
      char msg[64] = "ENGINE_rsa_priv_dec";
      if (!p_surewarehk_Rsa_Priv_Dec) {
          SUREWAREerr(SUREWARE_F_SUREWAREHK_RSA_PRIV_DEC,
                      ENGINE_R_NOT_INITIALISED);
      }
      /* extract ref to private key */
      else if (!(hptr = RSA_get_ex_data(rsa, rsaHndidx))) {
          SUREWAREerr(SUREWARE_F_SUREWAREHK_RSA_PRIV_DEC,
                      SUREWARE_R_MISSING_KEY_COMPONENTS);
          goto err;
      }
      /* analyse what padding we can do into the hardware */
      if (padding == RSA_PKCS1_PADDING) {
          /* do it one shot */
          ret =
              p_surewarehk_Rsa_Priv_Dec(msg, flen, (unsigned char *)from, &tlen,
                                        to, hptr, SUREWARE_PKCS1_PAD);
          surewarehk_error_handling(msg, SUREWARE_F_SUREWAREHK_RSA_PRIV_DEC,
                                    ret);
          if (ret != 1)
              goto err;
          ret = tlen;
      } else {                    /* do with no padding into hardware */
  
          ret =
              p_surewarehk_Rsa_Priv_Dec(msg, flen, (unsigned char *)from, &tlen,
                                        to, hptr, SUREWARE_NO_PAD);
          surewarehk_error_handling(msg, SUREWARE_F_SUREWAREHK_RSA_PRIV_DEC,
                                    ret);
          if (ret != 1)
              goto err;
          /* intermediate buffer for padding */
          if ((buf = OPENSSL_malloc(tlen)) == NULL) {
              SUREWAREerr(SUREWARE_F_SUREWAREHK_RSA_PRIV_DEC,
                          ERR_R_MALLOC_FAILURE);
              goto err;
          }
          memcpy(buf, to, tlen);  /* transfert to into buf */
          switch (padding) {      /* check padding in software */
  #   ifndef OPENSSL_NO_SHA
          case RSA_PKCS1_OAEP_PADDING:
              ret =
                  RSA_padding_check_PKCS1_OAEP(to, tlen, (unsigned char *)buf,
                                               tlen, tlen, NULL, 0);
              break;
  #   endif
          case RSA_SSLV23_PADDING:
              ret =
                  RSA_padding_check_SSLv23(to, tlen, (unsigned char *)buf, flen,
                                           tlen);
              break;
          case RSA_NO_PADDING:
              ret =
                  RSA_padding_check_none(to, tlen, (unsigned char *)buf, flen,
                                         tlen);
              break;
          default:
              SUREWAREerr(SUREWARE_F_SUREWAREHK_RSA_PRIV_DEC,
                          SUREWARE_R_UNKNOWN_PADDING_TYPE);
              goto err;
          }
          if (ret < 0)
              SUREWAREerr(SUREWARE_F_SUREWAREHK_RSA_PRIV_DEC,
                          SUREWARE_R_PADDING_CHECK_FAILED);
      }
   err:
      if (buf) {
          OPENSSL_cleanse(buf, tlen);
          OPENSSL_free(buf);
      }
      return ret;
  }
  
  /*
   * Does what OpenSSL rsa_priv_enc does.
   */
  static int surewarehk_rsa_sign(int flen, const unsigned char *from,
                                 unsigned char *to, RSA *rsa, int padding)
  {
      int ret = 0, tlen;
      char *hptr = NULL;
      char msg[64] = "ENGINE_rsa_sign";
      if (!p_surewarehk_Rsa_Sign) {
          SUREWAREerr(SUREWARE_F_SUREWAREHK_RSA_SIGN, ENGINE_R_NOT_INITIALISED);
      }
      /* extract ref to private key */
      else if (!(hptr = RSA_get_ex_data(rsa, rsaHndidx))) {
          SUREWAREerr(SUREWARE_F_SUREWAREHK_RSA_SIGN,
                      SUREWARE_R_MISSING_KEY_COMPONENTS);
      } else {
          switch (padding) {
          case RSA_PKCS1_PADDING: /* do it in one shot */
              ret =
                  p_surewarehk_Rsa_Sign(msg, flen, (unsigned char *)from, &tlen,
                                        to, hptr, SUREWARE_PKCS1_PAD);
              surewarehk_error_handling(msg, SUREWARE_F_SUREWAREHK_RSA_SIGN,
                                        ret);
              break;
          case RSA_NO_PADDING:
          default:
              SUREWAREerr(SUREWARE_F_SUREWAREHK_RSA_SIGN,
                          SUREWARE_R_UNKNOWN_PADDING_TYPE);
          }
      }
      return ret == 1 ? tlen : ret;
  }
  
  #  endif
  
  #  ifndef OPENSSL_NO_DSA
  /* DSA sign and verify */
  static DSA_SIG *surewarehk_dsa_do_sign(const unsigned char *from, int flen,
                                         DSA *dsa)
  {
      int ret = 0;
      char *hptr = NULL;
      DSA_SIG *psign = NULL;
      char msg[64] = "ENGINE_dsa_do_sign";
      if (!p_surewarehk_Dsa_Sign) {
          SUREWAREerr(SUREWARE_F_SUREWAREHK_DSA_DO_SIGN,
                      ENGINE_R_NOT_INITIALISED);
          goto err;
      }
      /* extract ref to private key */
      else if (!(hptr = DSA_get_ex_data(dsa, dsaHndidx))) {
          SUREWAREerr(SUREWARE_F_SUREWAREHK_DSA_DO_SIGN,
                      SUREWARE_R_MISSING_KEY_COMPONENTS);
          goto err;
      } else {
          if ((psign = DSA_SIG_new()) == NULL) {
              SUREWAREerr(SUREWARE_F_SUREWAREHK_DSA_DO_SIGN,
                          ERR_R_MALLOC_FAILURE);
              goto err;
          }
          psign->r = BN_new();
          psign->s = BN_new();
          bn_expand2(psign->r, 20 / sizeof(BN_ULONG));
          bn_expand2(psign->s, 20 / sizeof(BN_ULONG));
          if (!psign->r || psign->r->dmax != 20 / sizeof(BN_ULONG) ||
              !psign->s || psign->s->dmax != 20 / sizeof(BN_ULONG))
              goto err;
          ret = p_surewarehk_Dsa_Sign(msg, flen, from,
                                      (unsigned long *)psign->r->d,
                                      (unsigned long *)psign->s->d, hptr);
          surewarehk_error_handling(msg, SUREWARE_F_SUREWAREHK_DSA_DO_SIGN,
                                    ret);
      }
      psign->r->top = 20 / sizeof(BN_ULONG);
      bn_fix_top(psign->r);
      psign->s->top = 20 / sizeof(BN_ULONG);
      bn_fix_top(psign->s);
  
   err:
      if (psign) {
          DSA_SIG_free(psign);
          psign = NULL;
      }
      return psign;
  }
  #  endif
  
  static int surewarehk_modexp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
                               const BIGNUM *m, BN_CTX *ctx)
  {
      int ret = 0;
      char msg[64] = "ENGINE_modexp";
      if (!p_surewarehk_Mod_Exp) {
          SUREWAREerr(SUREWARE_F_SUREWAREHK_MODEXP, ENGINE_R_NOT_INITIALISED);
      } else {
          bn_expand2(r, m->top);
          if (r && r->dmax == m->top) {
              /* do it */
              ret = p_surewarehk_Mod_Exp(msg,
                                         m->top * sizeof(BN_ULONG),
                                         (unsigned long *)m->d,
                                         p->top * sizeof(BN_ULONG),
                                         (unsigned long *)p->d,
                                         a->top * sizeof(BN_ULONG),
                                         (unsigned long *)a->d,
                                         (unsigned long *)r->d);
              surewarehk_error_handling(msg, SUREWARE_F_SUREWAREHK_MODEXP, ret);
              if (ret == 1) {
                  /* normalise result */
                  r->top = m->top;
                  bn_fix_top(r);
              }
          }
      }
      return ret;
  }
  # endif                         /* !OPENSSL_NO_HW_SureWare */
  #endif                          /* !OPENSSL_NO_HW */
  