/* crypto/engine/hw_cswift.c */

/*

 * Written by Geoff Thorpe (geoff@geoffthorpe.net) for the OpenSSL project

 * 2000.

 */

/* ====================================================================

 * Copyright (c) 1999-2001 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/rand.h>

#include <openssl/bn.h>

#ifndef OPENSSL_NO_HW

# ifndef OPENSSL_NO_HW_CSWIFT

/*

 * Attribution notice: Rainbow have generously allowed me to reproduce the

 * necessary definitions here from their API. This means the support can

 * build independently of whether application builders have the API or

 * hardware. This will allow developers to easily produce software that has

 * latent hardware support for any users that have accelerators installed,

 * without the developers themselves needing anything extra. I have only

 * clipped the parts from the CryptoSwift header files that are (or seem)

 * relevant to the CryptoSwift support code. This is simply to keep the file

 * sizes reasonable. [Geoff]

 */

#  ifdef FLAT_INC

#   include "cswift.h"

#  else

#   include "vendor_defns/cswift.h"

#  endif

#  define CSWIFT_LIB_NAME "cswift engine"

#  include "e_cswift_err.c"

#  define DECIMAL_SIZE(type)      ((sizeof(type)*8+2)/3+1)

static int cswift_destroy(ENGINE *e);

static int cswift_init(ENGINE *e);

static int cswift_finish(ENGINE *e);

static int cswift_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f) (void));

#  ifndef OPENSSL_NO_RSA

static int cswift_bn_32copy(SW_LARGENUMBER *out, const BIGNUM *in);

#  endif

/* BIGNUM stuff */

static int cswift_mod_exp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,

                          const BIGNUM *m, BN_CTX *ctx);

#  ifndef OPENSSL_NO_RSA

static int cswift_mod_exp_crt(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,

                              const BIGNUM *q, const BIGNUM *dmp1,

                              const BIGNUM *dmq1, const BIGNUM *iqmp,

                              BN_CTX *ctx);

#  endif

#  ifndef OPENSSL_NO_RSA

/* RSA stuff */

static int cswift_rsa_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa,

                              BN_CTX *ctx);

/* This function is aliased to mod_exp (with the mont stuff dropped). */

static int cswift_mod_exp_mont(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,

                               const BIGNUM *m, BN_CTX *ctx,

                               BN_MONT_CTX *m_ctx);

#  endif

#  ifndef OPENSSL_NO_DSA

/* DSA stuff */

static DSA_SIG *cswift_dsa_sign(const unsigned char *dgst, int dlen,

                                DSA *dsa);

static int cswift_dsa_verify(const unsigned char *dgst, int dgst_len,

                             DSA_SIG *sig, DSA *dsa);

#  endif

#  ifndef OPENSSL_NO_DH

/* DH stuff */

/* This function is alised to mod_exp (with the DH and mont dropped). */

static int cswift_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);

#  endif

/* RAND stuff */

static int cswift_rand_bytes(unsigned char *buf, int num);

static int cswift_rand_status(void);

/* The definitions for control commands specific to this engine */

#  define CSWIFT_CMD_SO_PATH              ENGINE_CMD_BASE

static const ENGINE_CMD_DEFN cswift_cmd_defns[] = {

    {CSWIFT_CMD_SO_PATH,

     "SO_PATH",

     "Specifies the path to the 'cswift' shared library",

     ENGINE_CMD_FLAG_STRING},

    {0, NULL, NULL, 0}

};

#  ifndef OPENSSL_NO_RSA

/* Our internal RSA_METHOD that we provide pointers to */

static RSA_METHOD cswift_rsa = {

    "CryptoSwift RSA method",

    NULL,

    NULL,

    NULL,

    NULL,

    cswift_rsa_mod_exp,

    cswift_mod_exp_mont,

    NULL,

    NULL,

    0,

    NULL,

    NULL,

    NULL,

    NULL

};

#  endif

#  ifndef OPENSSL_NO_DSA

/* Our internal DSA_METHOD that we provide pointers to */

static DSA_METHOD cswift_dsa = {

    "CryptoSwift DSA method",

    cswift_dsa_sign,

    NULL,                       /* dsa_sign_setup */

    cswift_dsa_verify,

    NULL,                       /* dsa_mod_exp */

    NULL,                       /* bn_mod_exp */

    NULL,                       /* init */

    NULL,                       /* finish */

    0,                          /* flags */

    NULL,                       /* app_data */

    NULL,                       /* dsa_paramgen */

    NULL                        /* dsa_keygen */

};

#  endif

#  ifndef OPENSSL_NO_DH

/* Our internal DH_METHOD that we provide pointers to */

static DH_METHOD cswift_dh = {

    "CryptoSwift DH method",

    NULL,

    NULL,

    cswift_mod_exp_dh,

    NULL,

    NULL,

    0,

    NULL,

    NULL

};

#  endif

static RAND_METHOD cswift_random = {

    /* "CryptoSwift RAND method", */

    NULL,

    cswift_rand_bytes,

    NULL,

    NULL,

    cswift_rand_bytes,

    cswift_rand_status,

};

/* Constants used when creating the ENGINE */

static const char *engine_cswift_id = "cswift";

static const char *engine_cswift_name = "CryptoSwift hardware engine support";

/*

 * This internal function is used by ENGINE_cswift() 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_cswift_id) ||

        !ENGINE_set_name(e, engine_cswift_name) ||

#  ifndef OPENSSL_NO_RSA

        !ENGINE_set_RSA(e, &cswift_rsa) ||

#  endif

#  ifndef OPENSSL_NO_DSA

        !ENGINE_set_DSA(e, &cswift_dsa) ||

#  endif

#  ifndef OPENSSL_NO_DH

        !ENGINE_set_DH(e, &cswift_dh) ||

#  endif

        !ENGINE_set_RAND(e, &cswift_random) ||

        !ENGINE_set_destroy_function(e, cswift_destroy) ||

        !ENGINE_set_init_function(e, cswift_init) ||

        !ENGINE_set_finish_function(e, cswift_finish) ||

        !ENGINE_set_ctrl_function(e, cswift_ctrl) ||

        !ENGINE_set_cmd_defns(e, cswift_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();

    cswift_rsa.rsa_pub_enc = meth1->rsa_pub_enc;

    cswift_rsa.rsa_pub_dec = meth1->rsa_pub_dec;

    cswift_rsa.rsa_priv_enc = meth1->rsa_priv_enc;

    cswift_rsa.rsa_priv_dec = meth1->rsa_priv_dec;

#  endif

#  ifndef OPENSSL_NO_DH

    /* Much the same for Diffie-Hellman */

    meth2 = DH_OpenSSL();

    cswift_dh.generate_key = meth2->generate_key;

    cswift_dh.compute_key = meth2->compute_key;

#  endif

    /* Ensure the cswift error handling is set up */

    ERR_load_CSWIFT_strings();

    return 1;

}

#  ifdef OPENSSL_NO_DYNAMIC_ENGINE

static ENGINE *engine_cswift(void)

{

    ENGINE *ret = ENGINE_new();

    if (!ret)

        return NULL;

    if (!bind_helper(ret)) {

        ENGINE_free(ret);

        return NULL;

    }

    return ret;

}

void ENGINE_load_cswift(void)

{

    /* Copied from eng_[openssl|dyn].c */

    ENGINE *toadd = engine_cswift();

    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

 * CryptoSwift 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 *cswift_dso = NULL;

/*

 * These are the function pointers that are (un)set when the library has

 * successfully (un)loaded.

 */

t_swAcquireAccContext *p_CSwift_AcquireAccContext = NULL;

t_swAttachKeyParam *p_CSwift_AttachKeyParam = NULL;

t_swSimpleRequest *p_CSwift_SimpleRequest = NULL;

t_swReleaseAccContext *p_CSwift_ReleaseAccContext = NULL;

/* Used in the DSO operations. */

static const char *CSWIFT_LIBNAME = NULL;

static const char *get_CSWIFT_LIBNAME(void)

{

    if (CSWIFT_LIBNAME)

        return CSWIFT_LIBNAME;

    return "swift";

}

static void free_CSWIFT_LIBNAME(void)

{

    if (CSWIFT_LIBNAME)

        OPENSSL_free((void *)CSWIFT_LIBNAME);

    CSWIFT_LIBNAME = NULL;

}

static long set_CSWIFT_LIBNAME(const char *name)

{

    free_CSWIFT_LIBNAME();

    return (((CSWIFT_LIBNAME = BUF_strdup(name)) != NULL) ? 1 : 0);

}

static const char *CSWIFT_F1 = "swAcquireAccContext";

static const char *CSWIFT_F2 = "swAttachKeyParam";

static const char *CSWIFT_F3 = "swSimpleRequest";

static const char *CSWIFT_F4 = "swReleaseAccContext";

/*

 * CryptoSwift 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.

 */

/* utility function to obtain a context */

static int get_context(SW_CONTEXT_HANDLE *hac)

{

    SW_STATUS status;

    status = p_CSwift_AcquireAccContext(hac);

    if (status != SW_OK)

        return 0;

    return 1;

}

/* similarly to release one. */

static void release_context(SW_CONTEXT_HANDLE hac)

{

    p_CSwift_ReleaseAccContext(hac);

}

/* Destructor (complements the "ENGINE_cswift()" constructor) */

static int cswift_destroy(ENGINE *e)

{

    free_CSWIFT_LIBNAME();

    ERR_unload_CSWIFT_strings();

    return 1;

}

/* (de)initialisation functions. */

static int cswift_init(ENGINE *e)

{

    SW_CONTEXT_HANDLE hac;

    t_swAcquireAccContext *p1;

    t_swAttachKeyParam *p2;

    t_swSimpleRequest *p3;

    t_swReleaseAccContext *p4;

    if (cswift_dso != NULL) {

        CSWIFTerr(CSWIFT_F_CSWIFT_INIT, CSWIFT_R_ALREADY_LOADED);

        goto err;

    }

    /* Attempt to load libswift.so/swift.dll/whatever. */

    cswift_dso = DSO_load(NULL, get_CSWIFT_LIBNAME(), NULL, 0);

    if (cswift_dso == NULL) {

        CSWIFTerr(CSWIFT_F_CSWIFT_INIT, CSWIFT_R_NOT_LOADED);

        goto err;

    }

    if (!(p1 = (t_swAcquireAccContext *)

          DSO_bind_func(cswift_dso, CSWIFT_F1)) ||

        !(p2 = (t_swAttachKeyParam *)

          DSO_bind_func(cswift_dso, CSWIFT_F2)) ||

        !(p3 = (t_swSimpleRequest *)

          DSO_bind_func(cswift_dso, CSWIFT_F3)) ||

        !(p4 = (t_swReleaseAccContext *)

          DSO_bind_func(cswift_dso, CSWIFT_F4))) {

        CSWIFTerr(CSWIFT_F_CSWIFT_INIT, CSWIFT_R_NOT_LOADED);

        goto err;

    }

    /* Copy the pointers */

    p_CSwift_AcquireAccContext = p1;

    p_CSwift_AttachKeyParam = p2;

    p_CSwift_SimpleRequest = p3;

    p_CSwift_ReleaseAccContext = p4;

    /*

     * Try and get a context - if not, we may have a DSO but no accelerator!

     */

    if (!get_context(&hac)) {

        CSWIFTerr(CSWIFT_F_CSWIFT_INIT, CSWIFT_R_UNIT_FAILURE);

        goto err;

    }

    release_context(hac);

    /* Everything's fine. */

    return 1;

 err:

    if (cswift_dso) {

        DSO_free(cswift_dso);

        cswift_dso = NULL;

    }

    p_CSwift_AcquireAccContext = NULL;

    p_CSwift_AttachKeyParam = NULL;

    p_CSwift_SimpleRequest = NULL;

    p_CSwift_ReleaseAccContext = NULL;

    return 0;

}

static int cswift_finish(ENGINE *e)

{

    free_CSWIFT_LIBNAME();

    if (cswift_dso == NULL) {

        CSWIFTerr(CSWIFT_F_CSWIFT_FINISH, CSWIFT_R_NOT_LOADED);

        return 0;

    }

    if (!DSO_free(cswift_dso)) {

        CSWIFTerr(CSWIFT_F_CSWIFT_FINISH, CSWIFT_R_UNIT_FAILURE);

        return 0;

    }

    cswift_dso = NULL;

    p_CSwift_AcquireAccContext = NULL;

    p_CSwift_AttachKeyParam = NULL;

    p_CSwift_SimpleRequest = NULL;

    p_CSwift_ReleaseAccContext = NULL;

    return 1;

}

static int cswift_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f) (void))

{

    int initialised = ((cswift_dso == NULL) ? 0 : 1);

    switch (cmd) {

    case CSWIFT_CMD_SO_PATH:

        if (p == NULL) {

            CSWIFTerr(CSWIFT_F_CSWIFT_CTRL, ERR_R_PASSED_NULL_PARAMETER);

            return 0;

        }

        if (initialised) {

            CSWIFTerr(CSWIFT_F_CSWIFT_CTRL, CSWIFT_R_ALREADY_LOADED);

            return 0;

        }

        return set_CSWIFT_LIBNAME((const char *)p);

    default:

        break;

    }

    CSWIFTerr(CSWIFT_F_CSWIFT_CTRL, CSWIFT_R_CTRL_COMMAND_NOT_IMPLEMENTED);

    return 0;

}

/* Un petit mod_exp */

static int cswift_mod_exp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,

                          const BIGNUM *m, BN_CTX *ctx)

{

    /*

     * I need somewhere to store temporary serialised values for use with the

     * CryptoSwift API calls. A neat cheat - I'll use BIGNUMs from the BN_CTX

     * but access their arrays directly as byte arrays <grin>. This way I

     * don't have to clean anything up.

     */

    BIGNUM *modulus;

    BIGNUM *exponent;

    BIGNUM *argument;

    BIGNUM *result;

    SW_STATUS sw_status;

    SW_LARGENUMBER arg, res;

    SW_PARAM sw_param;

    SW_CONTEXT_HANDLE hac;

    int to_return, acquired;

    modulus = exponent = argument = result = NULL;

    to_return = 0;              /* expect failure */

    acquired = 0;

    if (!get_context(&hac)) {

        CSWIFTerr(CSWIFT_F_CSWIFT_MOD_EXP, CSWIFT_R_UNIT_FAILURE);

        goto err;

    }

    acquired = 1;

    /* Prepare the params */

    BN_CTX_start(ctx);

    modulus = BN_CTX_get(ctx);

    exponent = BN_CTX_get(ctx);

    argument = BN_CTX_get(ctx);

    result = BN_CTX_get(ctx);

    if (!result) {

        CSWIFTerr(CSWIFT_F_CSWIFT_MOD_EXP, CSWIFT_R_BN_CTX_FULL);

        goto err;

    }

    if (!bn_wexpand(modulus, m->top) || !bn_wexpand(exponent, p->top) ||

        !bn_wexpand(argument, a->top) || !bn_wexpand(result, m->top)) {

        CSWIFTerr(CSWIFT_F_CSWIFT_MOD_EXP, CSWIFT_R_BN_EXPAND_FAIL);

        goto err;

    }

    sw_param.type = SW_ALG_EXP;

    sw_param.up.exp.modulus.nbytes = BN_bn2bin(m,

                                               (unsigned char *)modulus->d);

    sw_param.up.exp.modulus.value = (unsigned char *)modulus->d;

    sw_param.up.exp.exponent.nbytes = BN_bn2bin(p,

                                                (unsigned char *)exponent->d);

    sw_param.up.exp.exponent.value = (unsigned char *)exponent->d;

    /* Attach the key params */

    sw_status = p_CSwift_AttachKeyParam(hac, &sw_param);

    switch (sw_status) {

    case SW_OK:

        break;

    case SW_ERR_INPUT_SIZE:

        CSWIFTerr(CSWIFT_F_CSWIFT_MOD_EXP, CSWIFT_R_BAD_KEY_SIZE);

        goto err;

    default:

        {

            char tmpbuf[DECIMAL_SIZE(sw_status) + 1];

            CSWIFTerr(CSWIFT_F_CSWIFT_MOD_EXP, CSWIFT_R_REQUEST_FAILED);

            sprintf(tmpbuf, "%ld", sw_status);

            ERR_add_error_data(2, "CryptoSwift error number is ", tmpbuf);

        }

        goto err;

    }

    /* Prepare the argument and response */

    arg.nbytes = BN_bn2bin(a, (unsigned char *)argument->d);

    arg.value = (unsigned char *)argument->d;

    res.nbytes = BN_num_bytes(m);

    memset(result->d, 0, res.nbytes);

    res.value = (unsigned char *)result->d;

    /* Perform the operation */

    if ((sw_status = p_CSwift_SimpleRequest(hac, SW_CMD_MODEXP, &arg, 1,

                                            &res, 1)) != SW_OK) {

        char tmpbuf[DECIMAL_SIZE(sw_status) + 1];

        CSWIFTerr(CSWIFT_F_CSWIFT_MOD_EXP, CSWIFT_R_REQUEST_FAILED);

        sprintf(tmpbuf, "%ld", sw_status);

        ERR_add_error_data(2, "CryptoSwift error number is ", tmpbuf);

        goto err;

    }

    /* Convert the response */

    BN_bin2bn((unsigned char *)result->d, res.nbytes, r);

    to_return = 1;

 err:

    if (acquired)

        release_context(hac);

    BN_CTX_end(ctx);

    return to_return;

}

#  ifndef OPENSSL_NO_RSA

int cswift_bn_32copy(SW_LARGENUMBER *out, const BIGNUM *in)

{

    int mod;

    int numbytes = BN_num_bytes(in);

    mod = 0;

    while (((out->nbytes = (numbytes + mod)) % 32)) {

        mod++;

    }

    out->value = (unsigned char *)OPENSSL_malloc(out->nbytes);

    if (!out->value) {

        return 0;

    }

    BN_bn2bin(in, &out->value[mod]);

    if (mod)

        memset(out->value, 0, mod);

    return 1;

}

#  endif

#  ifndef OPENSSL_NO_RSA

/* Un petit mod_exp chinois */

static int cswift_mod_exp_crt(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,

                              const BIGNUM *q, const BIGNUM *dmp1,

                              const BIGNUM *dmq1, const BIGNUM *iqmp,

                              BN_CTX *ctx)

{

    SW_STATUS sw_status;

    SW_LARGENUMBER arg, res;

    SW_PARAM sw_param;

    SW_CONTEXT_HANDLE hac;

    BIGNUM *result = NULL;

    BIGNUM *argument = NULL;

    int to_return = 0;          /* expect failure */

    int acquired = 0;

    sw_param.up.crt.p.value = NULL;

    sw_param.up.crt.q.value = NULL;

    sw_param.up.crt.dmp1.value = NULL;

    sw_param.up.crt.dmq1.value = NULL;

    sw_param.up.crt.iqmp.value = NULL;

    if (!get_context(&hac)) {

        CSWIFTerr(CSWIFT_F_CSWIFT_MOD_EXP_CRT, CSWIFT_R_UNIT_FAILURE);

        goto err;

    }

    acquired = 1;

    /* Prepare the params */

    argument = BN_new();

    result = BN_new();

    if (!result || !argument) {

        CSWIFTerr(CSWIFT_F_CSWIFT_MOD_EXP_CRT, CSWIFT_R_BN_CTX_FULL);

        goto err;

    }

    sw_param.type = SW_ALG_CRT;

        /************************************************************************/

    /*

     * 04/02/2003

     */

    /*

     * Modified by Frederic Giudicelli (deny-all.com) to overcome the

     */

    /*

     * limitation of cswift with values not a multiple of 32

     */

        /************************************************************************/

    if (!cswift_bn_32copy(&sw_param.up.crt.p, p)) {

        CSWIFTerr(CSWIFT_F_CSWIFT_MOD_EXP_CRT, CSWIFT_R_BN_EXPAND_FAIL);

        goto err;

    }

    if (!cswift_bn_32copy(&sw_param.up.crt.q, q)) {

        CSWIFTerr(CSWIFT_F_CSWIFT_MOD_EXP_CRT, CSWIFT_R_BN_EXPAND_FAIL);

        goto err;

    }

    if (!cswift_bn_32copy(&sw_param.up.crt.dmp1, dmp1)) {

        CSWIFTerr(CSWIFT_F_CSWIFT_MOD_EXP_CRT, CSWIFT_R_BN_EXPAND_FAIL);

        goto err;

    }

    if (!cswift_bn_32copy(&sw_param.up.crt.dmq1, dmq1)) {

        CSWIFTerr(CSWIFT_F_CSWIFT_MOD_EXP_CRT, CSWIFT_R_BN_EXPAND_FAIL);

        goto err;

    }

    if (!cswift_bn_32copy(&sw_param.up.crt.iqmp, iqmp)) {

        CSWIFTerr(CSWIFT_F_CSWIFT_MOD_EXP_CRT, CSWIFT_R_BN_EXPAND_FAIL);

        goto err;

    }

    if (!bn_wexpand(argument, a->top) || !bn_wexpand(result, p->top + q->top)) {

        CSWIFTerr(CSWIFT_F_CSWIFT_MOD_EXP_CRT, CSWIFT_R_BN_EXPAND_FAIL);

        goto err;

    }

    /* Attach the key params */

    sw_status = p_CSwift_AttachKeyParam(hac, &sw_param);

    switch (sw_status) {

    case SW_OK:

        break;

    case SW_ERR_INPUT_SIZE:

        CSWIFTerr(CSWIFT_F_CSWIFT_MOD_EXP_CRT, CSWIFT_R_BAD_KEY_SIZE);

        goto err;

    default:

        {

            char tmpbuf[DECIMAL_SIZE(sw_status) + 1];

            CSWIFTerr(CSWIFT_F_CSWIFT_MOD_EXP_CRT, CSWIFT_R_REQUEST_FAILED);

            sprintf(tmpbuf, "%ld", sw_status);

            ERR_add_error_data(2, "CryptoSwift error number is ", tmpbuf);

        }

        goto err;

    }

    /* Prepare the argument and response */

    arg.nbytes = BN_bn2bin(a, (unsigned char *)argument->d);

    arg.value = (unsigned char *)argument->d;

    res.nbytes = 2 * BN_num_bytes(p);

    memset(result->d, 0, res.nbytes);

    res.value = (unsigned char *)result->d;

    /* Perform the operation */

    if ((sw_status = p_CSwift_SimpleRequest(hac, SW_CMD_MODEXP_CRT, &arg, 1,

                                            &res, 1)) != SW_OK) {

        char tmpbuf[DECIMAL_SIZE(sw_status) + 1];

        CSWIFTerr(CSWIFT_F_CSWIFT_MOD_EXP_CRT, CSWIFT_R_REQUEST_FAILED);

        sprintf(tmpbuf, "%ld", sw_status);

        ERR_add_error_data(2, "CryptoSwift error number is ", tmpbuf);

        goto err;

    }

    /* Convert the response */

    BN_bin2bn((unsigned char *)result->d, res.nbytes, r);

    to_return = 1;

 err:

    if (sw_param.up.crt.p.value)

        OPENSSL_free(sw_param.up.crt.p.value);

    if (sw_param.up.crt.q.value)

        OPENSSL_free(sw_param.up.crt.q.value);

    if (sw_param.up.crt.dmp1.value)

        OPENSSL_free(sw_param.up.crt.dmp1.value);

    if (sw_param.up.crt.dmq1.value)

        OPENSSL_free(sw_param.up.crt.dmq1.value);

    if (sw_param.up.crt.iqmp.value)

        OPENSSL_free(sw_param.up.crt.iqmp.value);

    if (result)

        BN_free(result);

    if (argument)

        BN_free(argument);

    if (acquired)

        release_context(hac);

    return to_return;

}

#  endif

#  ifndef OPENSSL_NO_RSA

static int cswift_rsa_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa,

                              BN_CTX *ctx)

{

    int to_return = 0;

    const RSA_METHOD *def_rsa_method;

    if (!rsa->p || !rsa->q || !rsa->dmp1 || !rsa->dmq1 || !rsa->iqmp) {

        CSWIFTerr(CSWIFT_F_CSWIFT_RSA_MOD_EXP,

                  CSWIFT_R_MISSING_KEY_COMPONENTS);

        goto err;

    }

    /* Try the limits of RSA (2048 bits) */

    if (BN_num_bytes(rsa->p) > 128 ||

        BN_num_bytes(rsa->q) > 128 ||

        BN_num_bytes(rsa->dmp1) > 128 ||

        BN_num_bytes(rsa->dmq1) > 128 || BN_num_bytes(rsa->iqmp) > 128) {

#   ifdef RSA_NULL

        def_rsa_method = RSA_null_method();

#   else

#    if 0

        def_rsa_method = RSA_PKCS1_RSAref();

#    else

        def_rsa_method = RSA_PKCS1_SSLeay();

#    endif

#   endif

        if (def_rsa_method)

            return def_rsa_method->rsa_mod_exp(r0, I, rsa, ctx);

    }

    to_return = cswift_mod_exp_crt(r0, I, rsa->p, rsa->q, rsa->dmp1,

                                   rsa->dmq1, rsa->iqmp, ctx);

 err:

    return to_return;

}

/* This function is aliased to mod_exp (with the mont stuff dropped). */

static int cswift_mod_exp_mont(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,

                               const BIGNUM *m, BN_CTX *ctx,

                               BN_MONT_CTX *m_ctx)

{

    const RSA_METHOD *def_rsa_method;

    /* Try the limits of RSA (2048 bits) */

    if (BN_num_bytes(r) > 256 ||

        BN_num_bytes(a) > 256 || BN_num_bytes(m) > 256) {

#   ifdef RSA_NULL

        def_rsa_method = RSA_null_method();

#   else

#    if 0

        def_rsa_method = RSA_PKCS1_RSAref();

#    else

        def_rsa_method = RSA_PKCS1_SSLeay();

#    endif

#   endif

        if (def_rsa_method)

            return def_rsa_method->bn_mod_exp(r, a, p, m, ctx, m_ctx);

    }

    return cswift_mod_exp(r, a, p, m, ctx);

}

#  endif                        /* OPENSSL_NO_RSA */

#  ifndef OPENSSL_NO_DSA

static DSA_SIG *cswift_dsa_sign(const unsigned char *dgst, int dlen, DSA *dsa)

{

    SW_CONTEXT_HANDLE hac;

    SW_PARAM sw_param;

    SW_STATUS sw_status;

    SW_LARGENUMBER arg, res;

    BN_CTX *ctx;

    BIGNUM *dsa_p = NULL;

    BIGNUM *dsa_q = NULL;

    BIGNUM *dsa_g = NULL;

    BIGNUM *dsa_key = NULL;

    BIGNUM *result = NULL;

    DSA_SIG *to_return = NULL;

    int acquired = 0;

    if ((ctx = BN_CTX_new()) == NULL)

        goto err;

    if (!get_context(&hac)) {

        CSWIFTerr(CSWIFT_F_CSWIFT_DSA_SIGN, CSWIFT_R_UNIT_FAILURE);

        goto err;

    }

    acquired = 1;

    /* Prepare the params */

    BN_CTX_start(ctx);

    dsa_p = BN_CTX_get(ctx);

    dsa_q = BN_CTX_get(ctx);

    dsa_g = BN_CTX_get(ctx);

    dsa_key = BN_CTX_get(ctx);

    result = BN_CTX_get(ctx);

    if (!result) {

        CSWIFTerr(CSWIFT_F_CSWIFT_DSA_SIGN, CSWIFT_R_BN_CTX_FULL);

        goto err;

    }

    if (!bn_wexpand(dsa_p, dsa->p->top) ||

        !bn_wexpand(dsa_q, dsa->q->top) ||

        !bn_wexpand(dsa_g, dsa->g->top) ||

        !bn_wexpand(dsa_key, dsa->priv_key->top) ||

        !bn_wexpand(result, dsa->p->top)) {

        CSWIFTerr(CSWIFT_F_CSWIFT_DSA_SIGN, CSWIFT_R_BN_EXPAND_FAIL);

        goto err;

    }

    sw_param.type = SW_ALG_DSA;

    sw_param.up.dsa.p.nbytes = BN_bn2bin(dsa->p, (unsigned char *)dsa_p->d);

    sw_param.up.dsa.p.value = (unsigned char *)dsa_p->d;

    sw_param.up.dsa.q.nbytes = BN_bn2bin(dsa->q, (unsigned char *)dsa_q->d);

    sw_param.up.dsa.q.value = (unsigned char *)dsa_q->d;

    sw_param.up.dsa.g.nbytes = BN_bn2bin(dsa->g, (unsigned char *)dsa_g->d);

    sw_param.up.dsa.g.value = (unsigned char *)dsa_g->d;

    sw_param.up.dsa.key.nbytes = BN_bn2bin(dsa->priv_key,

                                           (unsigned char *)dsa_key->d);

    sw_param.up.dsa.key.value = (unsigned char *)dsa_key->d;

    /* Attach the key params */

    sw_status = p_CSwift_AttachKeyParam(hac, &sw_param);

    switch (sw_status) {

    case SW_OK:

        break;

    case SW_ERR_INPUT_SIZE:

        CSWIFTerr(CSWIFT_F_CSWIFT_DSA_SIGN, CSWIFT_R_BAD_KEY_SIZE);

        goto err;

    default:

        {

            char tmpbuf[DECIMAL_SIZE(sw_status) + 1];

            CSWIFTerr(CSWIFT_F_CSWIFT_DSA_SIGN, CSWIFT_R_REQUEST_FAILED);

            sprintf(tmpbuf, "%ld", sw_status);

            ERR_add_error_data(2, "CryptoSwift error number is ", tmpbuf);

        }

        goto err;

    }

    /* Prepare the argument and response */

    arg.nbytes = dlen;

    arg.value = (unsigned char *)dgst;

    res.nbytes = BN_num_bytes(dsa->p);

    memset(result->d, 0, res.nbytes);

    res.value = (unsigned char *)result->d;

    /* Perform the operation */

    sw_status = p_CSwift_SimpleRequest(hac, SW_CMD_DSS_SIGN, &arg, 1,

                                       &res, 1);

    if (sw_status != SW_OK) {

        char tmpbuf[DECIMAL_SIZE(sw_status) + 1];

        CSWIFTerr(CSWIFT_F_CSWIFT_DSA_SIGN, CSWIFT_R_REQUEST_FAILED);

        sprintf(tmpbuf, "%ld", sw_status);

        ERR_add_error_data(2, "CryptoSwift error number is ", tmpbuf);

        goto err;

    }

    /* Convert the response */

    if ((to_return = DSA_SIG_new()) == NULL)

        goto err;

    to_return->r = BN_bin2bn((unsigned char *)result->d, 20, NULL);

    to_return->s = BN_bin2bn((unsigned char *)result->d + 20, 20, NULL);

 err:

    if (acquired)

        release_context(hac);

    if (ctx) {

        BN_CTX_end(ctx);

        BN_CTX_free(ctx);

    }

    return to_return;

}

static int cswift_dsa_verify(const unsigned char *dgst, int dgst_len,

                             DSA_SIG *sig, DSA *dsa)

{

    SW_CONTEXT_HANDLE hac;

    SW_PARAM sw_param;

    SW_STATUS sw_status;

    SW_LARGENUMBER arg[2], res;

    unsigned long sig_result;

    BN_CTX *ctx;

    BIGNUM *dsa_p = NULL;

    BIGNUM *dsa_q = NULL;

    BIGNUM *dsa_g = NULL;

    BIGNUM *dsa_key = NULL;

    BIGNUM *argument = NULL;

    int to_return = -1;

    int acquired = 0;

    if ((ctx = BN_CTX_new()) == NULL)

        goto err;

    if (!get_context(&hac)) {

        CSWIFTerr(CSWIFT_F_CSWIFT_DSA_VERIFY, CSWIFT_R_UNIT_FAILURE);

        goto err;

    }

    acquired = 1;

    /* Prepare the params */

    BN_CTX_start(ctx);

    dsa_p = BN_CTX_get(ctx);

    dsa_q = BN_CTX_get(ctx);

    dsa_g = BN_CTX_get(ctx);

    dsa_key = BN_CTX_get(ctx);

    argument = BN_CTX_get(ctx);

    if (!argument) {

        CSWIFTerr(CSWIFT_F_CSWIFT_DSA_VERIFY, CSWIFT_R_BN_CTX_FULL);

        goto err;

    }

    if (!bn_wexpand(dsa_p, dsa->p->top) ||

        !bn_wexpand(dsa_q, dsa->q->top) ||

        !bn_wexpand(dsa_g, dsa->g->top) ||

        !bn_wexpand(dsa_key, dsa->pub_key->top) ||

        !bn_wexpand(argument, 40)) {

        CSWIFTerr(CSWIFT_F_CSWIFT_DSA_VERIFY, CSWIFT_R_BN_EXPAND_FAIL);

        goto err;