static int keystore_engine_setup(ENGINE* e) {
    ALOGV("keystore_engine_setup");

    if (!ENGINE_set_id(e, KEYSTORE_ENGINE_ID)
            || !ENGINE_set_name(e, KEYSTORE_ENGINE_NAME)
            || !ENGINE_set_load_privkey_function(e, keystore_loadkey)
            || !ENGINE_set_load_pubkey_function(e, keystore_loadkey)
            || !ENGINE_set_cmd_defns(e, keystore_cmd_defns)) {
        ALOGE("Could not set up keystore engine");
        return 0;
    }

    if (!ENGINE_set_RSA(e, &keystore_rsa_meth)
            || !register_rsa_methods()) {
        ALOGE("Could not set up keystore RSA methods");
        return 0;
    }

    /* We need a handle in the RSA keys as well for keygen if it's not already initialized. */
    pthread_once(&rsa_key_handle_control, init_rsa_key_handle);
    if (rsa_key_handle < 0) {
        ALOGE("Could not set up RSA ex_data index");
        return 0;
    }

    return 1;
}

static int bind_afalg(ENGINE *e)
{
    /* Ensure the afalg error handling is set up */
    unsigned short i;
    ERR_load_AFALG_strings();

    if (!ENGINE_set_id(e, engine_afalg_id)
        || !ENGINE_set_name(e, engine_afalg_name)
        || !ENGINE_set_destroy_function(e, afalg_destroy)
        || !ENGINE_set_init_function(e, afalg_init)
        || !ENGINE_set_finish_function(e, afalg_finish)) {
        AFALGerr(AFALG_F_BIND_AFALG, AFALG_R_INIT_FAILED);
        return 0;
    }

    /*
     * Create _hidden_aes_xxx_cbc by calling afalg_aes_xxx_cbc
     * now, as bind_aflag can only be called by one thread at a
     * time.
     */
    for(i = 0; i < OSSL_NELEM(afalg_cipher_nids); i++) {
        if (afalg_aes_cbc(afalg_cipher_nids[i]) == NULL) {
            AFALGerr(AFALG_F_BIND_AFALG, AFALG_R_INIT_FAILED);
            return 0;
        }
    }

    if (!ENGINE_set_ciphers(e, afalg_ciphers)) {
        AFALGerr(AFALG_F_BIND_AFALG, AFALG_R_INIT_FAILED);
        return 0;
    }

    return 1;
}

static int bind_afalg(ENGINE *e)
{
    /* Ensure the afalg error handling is set up */
    ERR_load_AFALG_strings();

    if (!ENGINE_set_id(e, engine_afalg_id)
        || !ENGINE_set_name(e, engine_afalg_name)
        || !ENGINE_set_destroy_function(e, afalg_destroy)
        || !ENGINE_set_init_function(e, afalg_init)
        || !ENGINE_set_finish_function(e, afalg_finish)) {
        AFALGerr(AFALG_F_BIND_AFALG, AFALG_R_INIT_FAILED);
        return 0;
    }

    /*
     * Create _hidden_aes_128_cbc by calling afalg_aes_128_cbc
     * now, as bind_aflag can only be called by one thread at a
     * time.
     */
    if (afalg_aes_128_cbc() == NULL) {
        AFALGerr(AFALG_F_BIND_AFALG, AFALG_R_INIT_FAILED);
        return 0;
    }

    if (!ENGINE_set_ciphers(e, afalg_ciphers)) {
        AFALGerr(AFALG_F_BIND_AFALG, AFALG_R_INIT_FAILED);
        return 0;
    }

    return 1;
}

/* Prepare the ENGINE structure for registration */
static int padlock_bind_helper(ENGINE *e)
{
    /* Check available features */
    padlock_available();

    /*
     * RNG is currently disabled for reasons discussed in commentary just
     * before padlock_rand_bytes function.
     */
    padlock_use_rng = 0;

    /* Generate a nice engine name with available features */
    BIO_snprintf(padlock_name, sizeof(padlock_name),
                 "VIA PadLock (%s, %s)",
                 padlock_use_rng ? "RNG" : "no-RNG",
                 padlock_use_ace ? "ACE" : "no-ACE");

    /* Register everything or return with an error */
    if (!ENGINE_set_id(e, padlock_id) ||
        !ENGINE_set_name(e, padlock_name) ||
        !ENGINE_set_init_function(e, padlock_init) ||
#   ifndef OPENSSL_NO_AES
        (padlock_use_ace && !ENGINE_set_ciphers(e, padlock_ciphers)) ||
#   endif
        (padlock_use_rng && !ENGINE_set_RAND(e, &padlock_rand))) {
        return 0;
    }

    /* Everything looks good */
    return 1;
}

static int bind(ENGINE *e, const char *id)
{
  static int loaded = 0;
  int ret = 0;

  if (id && strcmp(id, engine_id)) {
    goto end;
  }

  if (loaded) {
    fprintf(stderr, "Useless engine already loaded\n");
    goto end;
  }

  loaded = 1;

  if (!ENGINE_set_id(e, engine_id)) {
    fprintf(stderr, "ENGINE_set_id failed\n");
    goto end;
  }
  if (!ENGINE_set_name(e, engine_name)) {
    printf("ENGINE_set_name failed\n");
    goto end;
  }

    ret = 1;
 end:
    return ret;
}

/* Prepare the ENGINE structure for registration */
static int
padlock_bind_helper(ENGINE *e)
{
	/* Check available features */
	padlock_available();

#if 1	/* disable RNG for now, see commentary in vicinity of RNG code */
	padlock_use_rng=0;
#endif

	/* Generate a nice engine name with available features */
	BIO_snprintf(padlock_name, sizeof(padlock_name),
		"VIA PadLock (%s, %s)", 
		 padlock_use_rng ? "RNG" : "no-RNG",
		 padlock_use_ace ? "ACE" : "no-ACE");

	/* Register everything or return with an error */ 
	if (!ENGINE_set_id(e, padlock_id) ||
	    !ENGINE_set_name(e, padlock_name) ||

	    !ENGINE_set_init_function(e, padlock_init) ||
#ifndef OPENSSL_NO_AES
	    (padlock_use_ace && !ENGINE_set_ciphers (e, padlock_ciphers)) ||
#endif
	    (padlock_use_rng && !ENGINE_set_RAND (e, &padlock_rand))) {
		return 0;
	}

	/* Everything looks good */
	return 1;
}

/* ---------------------*/
static int bind_helper(ENGINE *e)
{

    if (!ENGINE_set_id(e, engine_cluster_labs_id) ||
        !ENGINE_set_name(e, engine_cluster_labs_name) ||
#  ifndef OPENSSL_NO_RSA
        !ENGINE_set_RSA(e, &cluster_labs_rsa) ||
#  endif
#  ifndef OPENSSL_NO_DSA
        !ENGINE_set_DSA(e, &cluster_labs_dsa) ||
#  endif
#  ifndef OPENSSL_NO_DH
        !ENGINE_set_DH(e, &cluster_labs_dh) ||
#  endif
        !ENGINE_set_RAND(e, &cluster_labs_rand) ||
        !ENGINE_set_destroy_function(e, cluster_labs_destroy) ||
        !ENGINE_set_init_function(e, cluster_labs_init) ||
        !ENGINE_set_finish_function(e, cluster_labs_finish) ||
        !ENGINE_set_ctrl_function(e, cluster_labs_ctrl) ||
        !ENGINE_set_cmd_defns(e, cluster_labs_cmd_defns))
        return 0;
    /* Ensure the error handling is set up */
    ERR_load_CL_strings();
    return 1;
}

static int bind_helper(ENGINE * e) {
    if (!ENGINE_set_id(e, TEST_ENGINE_ID)
        || !ENGINE_set_name(e, TEST_ENGINE_NAME)
        || !ENGINE_set_ctrl_function(e, test_engine_ctrl)
        || !ENGINE_set_cmd_defns(e, te_cmd_defns)
        || !ENGINE_set_digests(e, te_digests)
        || !ENGINE_set_pkey_meths(e, te_pkey_meths)
        || !ENGINE_set_pkey_asn1_meths(e, te_pkey_asn1_meths) ) {
        printf("Engine init failed\n");
        return 0;
    }

    if (!register_ameth_gost(NID_hmac_sha1, &ameth_HMAC_SHA1, "hmac-sha1", "HMAC-SHA1 MAC")
        || !register_pmeth_gost(NID_hmac_sha1, &pmeth_HMAC_SHA1, 0)) {
        printf("Internal init failed\n");
        return 0;
    }

    if(!ENGINE_register_digests(e)
        || !ENGINE_register_pkey_meths(e)
        || !ENGINE_register_pkey_asn1_meths(e)
        || !EVP_add_digest(&digest_hmac_sha1)) {
        printf("Digest registration failed\n");
        return 0;
    }

    return 1;
}

static int bind_helper (ENGINE *e) {

	if (!ENGINE_set_id(e, FS_ENGINE_ID) ||
		!ENGINE_set_name (e, FS_ENGINE_NAME) ||
		!ENGINE_set_destroy_function (e, engine_fs_destroy) ||
		!ENGINE_set_finish_function (e, engine_fs_finish) ||
		!ENGINE_set_ctrl_function (e, engine_fs_ctrl) ||
		!ENGINE_set_load_privkey_function (e, engine_fs_load_private_key) ||
		!ENGINE_set_RSA (e, &engine_fs_rsa) /*||
		!ENGINE_set_load_pubkey_function (e, engine_fs_load_public_key) ||
		!ENGINE_set_init_function (e, engine_fs_init) ||
		!ENGINE_set_DSA (e, engine_fs_dsa) ||
		!ENGINE_set_ECDH (e, engine_fs_dh) ||
		!ENGINE_set_ECDSA (e, engine_fs_dh) ||
		!ENGINE_set_DH (e, engine_fs_dh) ||
		!ENGINE_set_RAND (e, engine_fs_rand) ||
		!ENGINE_set_STORE (e, asn1_i2d_ex_primitiveengine_fs_rand) ||
		!ENGINE_set_ciphers (e, engine_fs_syphers_f) ||
		!ENGINE_set_digests (e, engine_fs_digest_f) ||
		!ENGINE_set_flags (e, engine_fs_flags) ||
		!ENGINE_set_cmd_defns (e, engine_fs_cmd_defns)*/) {
		return (0);
	}
	
	if (!ENGINE_set_RSA (e, &engine_fs_rsa)
                || !register_rsa_methods ()) {
            return 0;
	}
	
	return (1);
}

/* This internal function is used by ENGINE_gmp() and possibly by the
 * "dynamic" ENGINE support too */
static int bind_helper(ENGINE *e)
	{
#ifndef OPENSSL_NO_RSA
	const RSA_METHOD *meth1;
#endif
	if(!ENGINE_set_id(e, engine_e_gmp_id) ||
			!ENGINE_set_name(e, engine_e_gmp_name) ||
#ifndef OPENSSL_NO_RSA
			!ENGINE_set_RSA(e, &e_gmp_rsa) ||
#endif
			!ENGINE_set_destroy_function(e, e_gmp_destroy) ||
			!ENGINE_set_init_function(e, e_gmp_init) ||
			!ENGINE_set_finish_function(e, e_gmp_finish) ||
			!ENGINE_set_ctrl_function(e, e_gmp_ctrl) ||
			!ENGINE_set_cmd_defns(e, e_gmp_cmd_defns))
		return 0;

#ifndef OPENSSL_NO_RSA
	meth1 = RSA_PKCS1_SSLeay();
	e_gmp_rsa.rsa_pub_enc = meth1->rsa_pub_enc;
	e_gmp_rsa.rsa_pub_dec = meth1->rsa_pub_dec;
	e_gmp_rsa.rsa_priv_enc = meth1->rsa_priv_enc;
	e_gmp_rsa.rsa_priv_dec = meth1->rsa_priv_dec;
	e_gmp_rsa.bn_mod_exp = meth1->bn_mod_exp;
#endif

	/* Ensure the e_gmp error handling is set up */
	ERR_load_GMP_strings();
	return 1;
	}

/*
 * This internal function is used by ENGINE_ubsec() and possibly by the
 * "dynamic" ENGINE support too
 */
static int bind_helper(ENGINE *e)
{
#  ifndef OPENSSL_NO_RSA
    const RSA_METHOD *meth1;
#  endif
#  ifndef OPENSSL_NO_DH
#   ifndef HAVE_UBSEC_DH
    const DH_METHOD *meth3;
#   endif                       /* HAVE_UBSEC_DH */
#  endif
    if (!ENGINE_set_id(e, engine_ubsec_id) ||
        !ENGINE_set_name(e, engine_ubsec_name) ||
#  ifndef OPENSSL_NO_RSA
        !ENGINE_set_RSA(e, &ubsec_rsa) ||
#  endif
#  ifndef OPENSSL_NO_DSA
        !ENGINE_set_DSA(e, &ubsec_dsa) ||
#  endif
#  ifndef OPENSSL_NO_DH
        !ENGINE_set_DH(e, &ubsec_dh) ||
#  endif
        !ENGINE_set_destroy_function(e, ubsec_destroy) ||
        !ENGINE_set_init_function(e, ubsec_init) ||
        !ENGINE_set_finish_function(e, ubsec_finish) ||
        !ENGINE_set_ctrl_function(e, ubsec_ctrl) ||
        !ENGINE_set_cmd_defns(e, ubsec_cmd_defns))
        return 0;

#  ifndef OPENSSL_NO_RSA
    /*
     * We know that the "PKCS1_OpenSSL()" functions hook properly to the
     * Broadcom-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_OpenSSL();
    ubsec_rsa.rsa_pub_enc = meth1->rsa_pub_enc;
    ubsec_rsa.rsa_pub_dec = meth1->rsa_pub_dec;
    ubsec_rsa.rsa_priv_enc = meth1->rsa_priv_enc;
    ubsec_rsa.rsa_priv_dec = meth1->rsa_priv_dec;
#  endif

#  ifndef OPENSSL_NO_DH
#   ifndef HAVE_UBSEC_DH
    /* Much the same for Diffie-Hellman */
    meth3 = DH_OpenSSL();
    ubsec_dh.generate_key = meth3->generate_key;
    ubsec_dh.compute_key = meth3->compute_key;
#   endif                       /* HAVE_UBSEC_DH */
#  endif

    /* Ensure the ubsec error handling is set up */
    ERR_load_UBSEC_strings();
    return 1;
}

    static ENGINE* LoadEngine()
    {
      // This function creates an engine for PKCS#11 and inspired by
      // the "ENGINE_load_dynamic" function from OpenSSL, in file
      // "crypto/engine/eng_dyn.c"

      ENGINE* engine = ENGINE_new();
      if (!engine)
      {
        LOG(ERROR) << "Cannot create an OpenSSL engine for PKCS#11";
        throw OrthancException(ErrorCode_InternalError);
      }

      // Create a PKCS#11 context using libp11
      context_ = pkcs11_new();
      if (!context_)
      {
        LOG(ERROR) << "Cannot create a libp11 context for PKCS#11";
        ENGINE_free(engine);
        throw OrthancException(ErrorCode_InternalError);
      }

      if (!ENGINE_set_id(engine, PKCS11_ENGINE_ID) ||
          !ENGINE_set_name(engine, PKCS11_ENGINE_NAME) ||
          !ENGINE_set_cmd_defns(engine, PKCS11_ENGINE_COMMANDS) ||

          // Register the callback functions
          !ENGINE_set_init_function(engine, EngineInitialize) ||
          !ENGINE_set_finish_function(engine, EngineFinalize) ||
          !ENGINE_set_destroy_function(engine, EngineDestroy) ||
          !ENGINE_set_ctrl_function(engine, EngineControl) ||
          !ENGINE_set_load_pubkey_function(engine, EngineLoadPublicKey) ||
          !ENGINE_set_load_privkey_function(engine, EngineLoadPrivateKey) ||

          !ENGINE_set_RSA(engine, PKCS11_get_rsa_method()) ||
          !ENGINE_set_ECDSA(engine, PKCS11_get_ecdsa_method()) ||
          !ENGINE_set_ECDH(engine, PKCS11_get_ecdh_method()) ||

#if OPENSSL_VERSION_NUMBER  >= 0x10100002L
          !ENGINE_set_EC(engine, PKCS11_get_ec_key_method()) ||
#endif

          // Make OpenSSL know about our PKCS#11 engine
          !ENGINE_add(engine))
      {
        LOG(ERROR) << "Cannot initialize the OpenSSL engine for PKCS#11";
        pkcs11_finish(context_);
        ENGINE_free(engine);
        throw OrthancException(ErrorCode_InternalError);
      }

      // If the "ENGINE_add" worked, it gets a structural
      // reference. We release our just-created reference.
      ENGINE_free(engine);

      return ENGINE_by_id(PKCS11_ENGINE_ID);
    }

static int bind_helper (ENGINE * e)
{
    if (!ENGINE_set_id (e, engine_e_rdrand_id) ||
        !ENGINE_set_name (e, engine_e_rdrand_name) ||
        !ENGINE_set_flags (e, ENGINE_FLAGS_NO_REGISTER_ALL) ||
        !ENGINE_set_init_function (e, rdrand_init) || !ENGINE_set_RAND (e, &rdrand_meth))
        return 0;

    return 1;
}

static int bind_helper(ENGINE *e)
	{
	if (!ENGINE_set_id(e, engine_e_rdrand_id) ||
	    !ENGINE_set_name(e, engine_e_rdrand_name) ||
	    !ENGINE_set_init_function(e, rdrand_init) ||
	    !ENGINE_set_RAND(e, &rdrand_meth) )
		return 0;

	return 1;
	}

static int bind_devcrypto(ENGINE *e) {

    if (!ENGINE_set_id(e, engine_devcrypto_id)
        || !ENGINE_set_name(e, "/dev/crypto engine")
        || !ENGINE_set_destroy_function(e, devcrypto_unload)
        || !ENGINE_set_cmd_defns(e, devcrypto_cmds)
        || !ENGINE_set_ctrl_function(e, devcrypto_ctrl))
        return 0;

    prepare_cipher_methods();
#ifdef IMPLEMENT_DIGEST
    prepare_digest_methods();
#endif

    return (ENGINE_set_ciphers(e, devcrypto_ciphers)
#ifdef IMPLEMENT_DIGEST
        && ENGINE_set_digests(e, devcrypto_digests)
#endif
/*
 * Asymmetric ciphers aren't well supported with /dev/crypto.  Among the BSD
 * implementations, it seems to only exist in FreeBSD, and regarding the
 * parameters in its crypt_kop, the manual crypto(4) has this to say:
 *
 *    The semantics of these arguments are currently undocumented.
 *
 * Reading through the FreeBSD source code doesn't give much more than
 * their CRK_MOD_EXP implementation for ubsec.
 *
 * It doesn't look much better with cryptodev-linux.  They have the crypt_kop
 * structure as well as the command (CRK_*) in cryptodev.h, but no support
 * seems to be implemented at all for the moment.
 *
 * At the time of writing, it seems impossible to write proper support for
 * FreeBSD's asym features without some very deep knowledge and access to
 * specific kernel modules.
 *
 * /Richard Levitte, 2017-05-11
 */
#if 0
# ifndef OPENSSL_NO_RSA
        && ENGINE_set_RSA(e, devcrypto_rsa)
# endif
# ifndef OPENSSL_NO_DSA
        && ENGINE_set_DSA(e, devcrypto_dsa)
# endif
# ifndef OPENSSL_NO_DH
        && ENGINE_set_DH(e, devcrypto_dh)
# endif
# ifndef OPENSSL_NO_EC
        && ENGINE_set_EC(e, devcrypto_ec)
# endif
#endif
        );
}

int bind_helper(ENGINE * e, const char *id)
{
  if (!ENGINE_set_id(e, engine_Everest_id) ||
    !ENGINE_set_name(e, engine_Everest_name) ||
    !ENGINE_set_init_function(e,Everest_init) ||
    !ENGINE_set_pkey_meths(e, Everest_pkey_meths)
  )
    return 0;

  return 1;
}

/*
 * This internal function is used by ENGINE_chil() and possibly by the
 * "dynamic" ENGINE support too
 */
static int bind_helper(ENGINE *e)
{
#  ifndef OPENSSL_NO_RSA
    const RSA_METHOD *meth1;
#  endif
#  ifndef OPENSSL_NO_DH
    const DH_METHOD *meth2;
#  endif
    if (!ENGINE_set_id(e, engine_hwcrhk_id) ||
        !ENGINE_set_name(e, engine_hwcrhk_name) ||
#  ifndef OPENSSL_NO_RSA
        !ENGINE_set_RSA(e, &hwcrhk_rsa) ||
#  endif
#  ifndef OPENSSL_NO_DH
        !ENGINE_set_DH(e, &hwcrhk_dh) ||
#  endif
        !ENGINE_set_RAND(e, &hwcrhk_rand) ||
        !ENGINE_set_destroy_function(e, hwcrhk_destroy) ||
        !ENGINE_set_init_function(e, hwcrhk_init) ||
        !ENGINE_set_finish_function(e, hwcrhk_finish) ||
        !ENGINE_set_ctrl_function(e, hwcrhk_ctrl) ||
        !ENGINE_set_load_privkey_function(e, hwcrhk_load_privkey) ||
        !ENGINE_set_load_pubkey_function(e, hwcrhk_load_pubkey) ||
        !ENGINE_set_cmd_defns(e, hwcrhk_cmd_defns))
        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();
    hwcrhk_rsa.rsa_pub_enc = meth1->rsa_pub_enc;
    hwcrhk_rsa.rsa_pub_dec = meth1->rsa_pub_dec;
    hwcrhk_rsa.rsa_priv_enc = meth1->rsa_priv_enc;
    hwcrhk_rsa.rsa_priv_dec = meth1->rsa_priv_dec;
#  endif

#  ifndef OPENSSL_NO_DH
    /* Much the same for Diffie-Hellman */
    meth2 = DH_OpenSSL();
    hwcrhk_dh.generate_key = meth2->generate_key;
    hwcrhk_dh.compute_key = meth2->compute_key;
#  endif

    /* Ensure the hwcrhk error handling is set up */
    ERR_load_HWCRHK_strings();
    return 1;
}

static int cuda_bind_helper(ENGINE * e) {
	if (!ENGINE_set_id(e, CUDA_ENGINE_ID) ||
	    !ENGINE_set_init_function(e, cuda_init) ||
	    !ENGINE_set_finish_function(e, cuda_finish) ||
	    !ENGINE_set_ctrl_function(e, cuda_engine_ctrl) ||
	    !ENGINE_set_cmd_defns(e, cuda_cmd_defns) ||
	    !ENGINE_set_name(e, CUDA_ENGINE_NAME) ||
	    !ENGINE_set_ciphers (e, cuda_ciphers)) {
		return 0;
	} else {
		return 1;
	}
}

static int openssl_engine_id(lua_State*L){
	ENGINE* eng = CHECK_OBJECT(1,ENGINE,"openssl.engine");
	const char*id = NULL;
	int ret = 0;
	if(lua_isstring(L, 2)){
		id = luaL_checkstring(L, 2);
		ret = ENGINE_set_id(eng,id);
		lua_pushboolean(L, ret);
		return 1;
	}
	lua_pushstring(L, ENGINE_get_id(eng));
	return 1;
}

static ENGINE *engine_dynamic(void)
{
    ENGINE *ret = ENGINE_new();
    if (ret == NULL)
        return NULL;
    if (!ENGINE_set_id(ret, engine_dynamic_id) ||
        !ENGINE_set_name(ret, engine_dynamic_name) ||
        !ENGINE_set_init_function(ret, dynamic_init) ||
        !ENGINE_set_finish_function(ret, dynamic_finish) ||
        !ENGINE_set_ctrl_function(ret, dynamic_ctrl) ||
        !ENGINE_set_flags(ret, ENGINE_FLAGS_BY_ID_COPY) ||
        !ENGINE_set_cmd_defns(ret, dynamic_cmd_defns)) {
        ENGINE_free(ret);
        return NULL;
    }
    return ret;
}