/* crypto/engine/hw_nuron.c */
/*
 * Written by Ben Laurie for the OpenSSL Project, leaning heavily on Geoff
 * Thorpe's Atalla implementation.
 */
/* ====================================================================
 * Copyright (c) 2000-2001 The OpenSSL Project.  All rights reserved.
 *
 * 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/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED 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 THE OpenSSL PROJECT OR
 * ITS CONTRIBUTORS 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.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * (eay@cryptsoft.com).  This product includes software written by Tim
 * Hudson (tjh@cryptsoft.com).
 *
 */

#include <stdio.h>
#include <string.h>
#include <openssl/crypto.h>
#include <openssl/buffer.h>
#include <openssl/dso.h>
#include <openssl/engine.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_NURON

#  define NURON_LIB_NAME "nuron engine"
#  include "e_nuron_err.c"

static const char *NURON_LIBNAME = NULL;
static const char *get_NURON_LIBNAME(void)
{
    if (NURON_LIBNAME)
        return NURON_LIBNAME;
    return "nuronssl";
}

static void free_NURON_LIBNAME(void)
{
    if (NURON_LIBNAME)
        OPENSSL_free((void *)NURON_LIBNAME);
    NURON_LIBNAME = NULL;
}

static long set_NURON_LIBNAME(const char *name)
{
    free_NURON_LIBNAME();
    return (((NURON_LIBNAME = BUF_strdup(name)) != NULL) ? 1 : 0);
}

static const char *NURON_F1 = "nuron_mod_exp";

/* The definitions for control commands specific to this engine */
#  define NURON_CMD_SO_PATH               ENGINE_CMD_BASE
static const ENGINE_CMD_DEFN nuron_cmd_defns[] = {
    {NURON_CMD_SO_PATH,
     "SO_PATH",
     "Specifies the path to the 'nuronssl' shared library",
     ENGINE_CMD_FLAG_STRING},
    {0, NULL, NULL, 0}
};

typedef int tfnModExp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
                      const BIGNUM *m);
static tfnModExp *pfnModExp = NULL;

static DSO *pvDSOHandle = NULL;

static int nuron_destroy(ENGINE *e)
{
    free_NURON_LIBNAME();
    ERR_unload_NURON_strings();
    return 1;
}

static int nuron_init(ENGINE *e)
{
    if (pvDSOHandle != NULL) {
        NURONerr(NURON_F_NURON_INIT, NURON_R_ALREADY_LOADED);
        return 0;
    }

    pvDSOHandle = DSO_load(NULL, get_NURON_LIBNAME(), NULL,
                           DSO_FLAG_NAME_TRANSLATION_EXT_ONLY);
    if (!pvDSOHandle) {
        NURONerr(NURON_F_NURON_INIT, NURON_R_DSO_NOT_FOUND);
        return 0;
    }

    pfnModExp = (tfnModExp *) DSO_bind_func(pvDSOHandle, NURON_F1);
    if (!pfnModExp) {
        NURONerr(NURON_F_NURON_INIT, NURON_R_DSO_FUNCTION_NOT_FOUND);
        return 0;
    }

    return 1;
}

static int nuron_finish(ENGINE *e)
{
    free_NURON_LIBNAME();
    if (pvDSOHandle == NULL) {
        NURONerr(NURON_F_NURON_FINISH, NURON_R_NOT_LOADED);
        return 0;
    }
    if (!DSO_free(pvDSOHandle)) {
        NURONerr(NURON_F_NURON_FINISH, NURON_R_DSO_FAILURE);
        return 0;
    }
    pvDSOHandle = NULL;
    pfnModExp = NULL;
    return 1;
}

static int nuron_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f) (void))
{
    int initialised = ((pvDSOHandle == NULL) ? 0 : 1);
    switch (cmd) {
    case NURON_CMD_SO_PATH:
        if (p == NULL) {
            NURONerr(NURON_F_NURON_CTRL, ERR_R_PASSED_NULL_PARAMETER);
            return 0;
        }
        if (initialised) {
            NURONerr(NURON_F_NURON_CTRL, NURON_R_ALREADY_LOADED);
            return 0;
        }
        return set_NURON_LIBNAME((const char *)p);
    default:
        break;
    }
    NURONerr(NURON_F_NURON_CTRL, NURON_R_CTRL_COMMAND_NOT_IMPLEMENTED);
    return 0;
}

static int nuron_mod_exp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
                         const BIGNUM *m, BN_CTX *ctx)
{
    if (!pvDSOHandle) {
        NURONerr(NURON_F_NURON_MOD_EXP, NURON_R_NOT_LOADED);
        return 0;
    }
    return pfnModExp(r, a, p, m);
}

#  ifndef OPENSSL_NO_RSA
static int nuron_rsa_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa,
                             BN_CTX *ctx)
{
    return nuron_mod_exp(r0, I, rsa->d, rsa->n, ctx);
}
#  endif

#  ifndef OPENSSL_NO_DSA
/*
 * This code was liberated and adapted from the commented-out code in
 * dsa_ossl.c. Because of the unoptimised form of the Atalla acceleration (it
 * doesn't have a CRT form for RSA), this function means that an Atalla
 * system running with a DSA server certificate can handshake around 5 or 6
 * times faster/more than an equivalent system running with RSA. Just check
 * out the "signs" statistics from the RSA and DSA parts of "openssl speed
 * -engine atalla dsa1024 rsa1024".
 */
static int nuron_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 (!nuron_mod_exp(rr, a1, p1, m, ctx))
        goto end;
    /* let t = a2 ^ p2 mod m */
    if (!nuron_mod_exp(&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 int nuron_mod_exp_dsa(DSA *dsa, BIGNUM *r, BIGNUM *a,
                             const BIGNUM *p, const BIGNUM *m, BN_CTX *ctx,
                             BN_MONT_CTX *m_ctx)
{
    return nuron_mod_exp(r, a, p, m, ctx);
}
#  endif

/* This function is aliased to mod_exp (with the mont stuff dropped). */
#  ifndef OPENSSL_NO_RSA
static int nuron_mod_exp_mont(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
                              const BIGNUM *m, BN_CTX *ctx,
                              BN_MONT_CTX *m_ctx)
{
    return nuron_mod_exp(r, a, p, m, ctx);
}
#  endif

#  ifndef OPENSSL_NO_DH
/* This function is aliased to mod_exp (with the dh and mont dropped). */
static int nuron_mod_exp_dh(const DH *dh, BIGNUM *r,
                            const BIGNUM *a, const BIGNUM *p,
                            const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx)
{
    return nuron_mod_exp(r, a, p, m, ctx);
}
#  endif

#  ifndef OPENSSL_NO_RSA
static RSA_METHOD nuron_rsa = {
    "Nuron RSA method",
    NULL,
    NULL,
    NULL,
    NULL,
    nuron_rsa_mod_exp,
    nuron_mod_exp_mont,
    NULL,
    NULL,
    0,
    NULL,
    NULL,
    NULL,
    NULL
};
#  endif

#  ifndef OPENSSL_NO_DSA
static DSA_METHOD nuron_dsa = {
    "Nuron DSA method",
    NULL,                       /* dsa_do_sign */
    NULL,                       /* dsa_sign_setup */
    NULL,                       /* dsa_do_verify */
    nuron_dsa_mod_exp,          /* dsa_mod_exp */
    nuron_mod_exp_dsa,          /* bn_mod_exp */
    NULL,                       /* init */
    NULL,                       /* finish */
    0,                          /* flags */
    NULL,                       /* app_data */
    NULL,                       /* dsa_paramgen */
    NULL                        /* dsa_keygen */
};
#  endif

#  ifndef OPENSSL_NO_DH
static DH_METHOD nuron_dh = {
    "Nuron DH method",
    NULL,
    NULL,
    nuron_mod_exp_dh,
    NULL,
    NULL,
    0,
    NULL,
    NULL
};
#  endif

/* Constants used when creating the ENGINE */
static const char *engine_nuron_id = "nuron";
static const char *engine_nuron_name = "Nuron hardware engine support";

/*
 * This internal function is used by ENGINE_nuron() 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_DSA
    const DSA_METHOD *meth2;
#  endif
#  ifndef OPENSSL_NO_DH
    const DH_METHOD *meth3;
#  endif
    if (!ENGINE_set_id(e, engine_nuron_id) ||
        !ENGINE_set_name(e, engine_nuron_name) ||
#  ifndef OPENSSL_NO_RSA
        !ENGINE_set_RSA(e, &nuron_rsa) ||
#  endif
#  ifndef OPENSSL_NO_DSA
        !ENGINE_set_DSA(e, &nuron_dsa) ||
#  endif
#  ifndef OPENSSL_NO_DH
        !ENGINE_set_DH(e, &nuron_dh) ||
#  endif
        !ENGINE_set_destroy_function(e, nuron_destroy) ||
        !ENGINE_set_init_function(e, nuron_init) ||
        !ENGINE_set_finish_function(e, nuron_finish) ||
        !ENGINE_set_ctrl_function(e, nuron_ctrl) ||
        !ENGINE_set_cmd_defns(e, nuron_cmd_defns))
        return 0;

#  ifndef OPENSSL_NO_RSA
    /*
     * We know that the "PKCS1_SSLeay()" functions hook properly to the
     * nuron-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();
    nuron_rsa.rsa_pub_enc = meth1->rsa_pub_enc;
    nuron_rsa.rsa_pub_dec = meth1->rsa_pub_dec;
    nuron_rsa.rsa_priv_enc = meth1->rsa_priv_enc;
    nuron_rsa.rsa_priv_dec = meth1->rsa_priv_dec;
#  endif

#  ifndef OPENSSL_NO_DSA
    /*
     * Use the DSA_OpenSSL() method and just hook the mod_exp-ish bits.
     */
    meth2 = DSA_OpenSSL();
    nuron_dsa.dsa_do_sign = meth2->dsa_do_sign;
    nuron_dsa.dsa_sign_setup = meth2->dsa_sign_setup;
    nuron_dsa.dsa_do_verify = meth2->dsa_do_verify;
#  endif

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

    /* Ensure the nuron error handling is set up */
    ERR_load_NURON_strings();
    return 1;
}

#  ifdef OPENSSL_NO_DYNAMIC_ENGINE
static ENGINE *engine_nuron(void)
{
    ENGINE *ret = ENGINE_new();
    if (!ret)
        return NULL;
    if (!bind_helper(ret)) {
        ENGINE_free(ret);
        return NULL;
    }
    return ret;
}

void ENGINE_load_nuron(void)
{
    /* Copied from eng_[openssl|dyn].c */
    ENGINE *toadd = engine_nuron();
    if (!toadd)
        return;
    ENGINE_add(toadd);
    ENGINE_free(toadd);
    ERR_clear_error();
}
#  endif

/*
 * This stuff is needed if this ENGINE is being compiled into a
 * self-contained shared-library.
 */
#  ifndef OPENSSL_NO_DYNAMIC_ENGINE
static int bind_fn(ENGINE *e, const char *id)
{
    if (id && (strcmp(id, engine_nuron_id) != 0))
        return 0;
    if (!bind_helper(e))
        return 0;
    return 1;
}

IMPLEMENT_DYNAMIC_CHECK_FN()
    IMPLEMENT_DYNAMIC_BIND_FN(bind_fn)
#  endif                        /* OPENSSL_NO_DYNAMIC_ENGINE */
# endif                         /* !OPENSSL_NO_HW_NURON */
#endif                          /* !OPENSSL_NO_HW */