openssl/crypto/engine/hw_ubsec.c

/* crypto/engine/hw_ubsec.c */
/* Written by Geoff Thorpe (geoff@geoffthorpe.net) for the OpenSSL
 * project 2000.
 *
 * Cloned shamelessly by Joe Tardo. 
 */
/* ====================================================================
 * Copyright (c) 1999 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 <openssl/crypto.h>
#include "cryptlib.h"
#include <openssl/dso.h>
#include "engine_int.h"
#include <openssl/engine.h>

#ifndef OPENSSL_NO_HW
#ifndef OPENSSL_NO_HW_UBSEC

#ifdef FLAT_INC
#include "hw_ubsec.h"
#else
#include "vendor_defns/hw_ubsec.h"
#endif

static int ubsec_init(ENGINE *e);
static int ubsec_finish(ENGINE *e);
static int ubsec_mod_exp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
		const BIGNUM *m, BN_CTX *ctx);
static int ubsec_mod_exp_crt(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
			const BIGNUM *q, const BIGNUM *dp,
			const BIGNUM *dq, const BIGNUM *qinv, BN_CTX *ctx);
static int ubsec_rsa_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa);
static int ubsec_mod_exp_mont(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
		const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx);
#if NOT_USED
static int ubsec_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);
static int ubsec_mod_exp_dsa(DSA *dsa, BIGNUM *r, BIGNUM *a,
		const BIGNUM *p, const BIGNUM *m, BN_CTX *ctx,
		BN_MONT_CTX *m_ctx);
#endif
static DSA_SIG *ubsec_dsa_do_sign(const unsigned char *dgst, int dlen, DSA *dsa);
static int ubsec_dsa_verify(const unsigned char *dgst, int dgst_len,
                                DSA_SIG *sig, DSA *dsa);
static int ubsec_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);
static int ubsec_dh_compute_key(unsigned char *key,const BIGNUM *pub_key,DH *dh);
static int ubsec_dh_generate_key(DH *dh);

#if NOT_USED
static int ubsec_rand_bytes(unsigned char *buf, int num);
static int ubsec_rand_status(void);
#endif
 
/* Our internal RSA_METHOD that we provide pointers to */

static RSA_METHOD ubsec_rsa =
	{
	"UBSEC RSA method",
	NULL,
	NULL,
	NULL,
	NULL,
	ubsec_rsa_mod_exp,
	ubsec_mod_exp_mont,
	NULL,
	NULL,
	0,
	NULL,
	NULL,
	NULL
	};

/* Our internal DSA_METHOD that we provide pointers to */
static DSA_METHOD ubsec_dsa =
	{
	"UBSEC DSA method",
	ubsec_dsa_do_sign, /* dsa_do_sign */
	NULL, /* dsa_sign_setup */
	ubsec_dsa_verify, /* dsa_do_verify */
	NULL, /* ubsec_dsa_mod_exp */ /* dsa_mod_exp */
	NULL, /* ubsec_mod_exp_dsa */ /* bn_mod_exp */
	NULL, /* init */
	NULL, /* finish */
	0, /* flags */
	NULL /* app_data */
	};

/* Our internal DH_METHOD that we provide pointers to */
static DH_METHOD ubsec_dh =
	{
	"UBSEC DH method",
	ubsec_dh_generate_key,
	ubsec_dh_compute_key,
	ubsec_mod_exp_dh,
	NULL,
	NULL,
	0,
	NULL
	};

/* Our ENGINE structure. */
static ENGINE engine_ubsec =
        {
	"ubsec",
	"UBSEC hardware engine support",
	&ubsec_rsa,
	&ubsec_dsa,
	&ubsec_dh,
	NULL,
	ubsec_mod_exp,
	ubsec_mod_exp_crt,
	ubsec_init,
	ubsec_finish,
	NULL, /* no ctrl() */
	NULL, /* no load_privkey() */
	NULL, /* no load_pubkey() */
	0, /* no flags */
	0, 0, /* no references */
	NULL, NULL /* unlinked */
        };

/* As this is only ever called once, there's no need for locking
 * (indeed - the lock will already be held by our caller!!!) */
ENGINE *ENGINE_ubsec()
	{
	const RSA_METHOD *meth1;
#ifndef HAVE_UBSEC_DH
	const DH_METHOD *meth3;
#endif /* HAVE_UBSEC_DH */

	/* We know that the "PKCS1_SSLeay()" 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_SSLeay();
	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;

#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 */

	return &engine_ubsec;
	}

/* This is a process-global DSO handle used for loading and unloading
 * the UBSEC 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 *ubsec_dso = NULL;

/* These are the function pointers that are (un)set when the library has
 * successfully (un)loaded. */

static t_UBSEC_ubsec_bytes_to_bits *p_UBSEC_ubsec_bytes_to_bits = NULL;
static t_UBSEC_ubsec_bits_to_bytes *p_UBSEC_ubsec_bits_to_bytes = NULL;
static t_UBSEC_ubsec_open *p_UBSEC_ubsec_open = NULL;
static t_UBSEC_ubsec_close *p_UBSEC_ubsec_close = NULL;
static t_UBSEC_diffie_hellman_generate_ioctl 
	*p_UBSEC_diffie_hellman_generate_ioctl = NULL;
static t_UBSEC_diffie_hellman_agree_ioctl *p_UBSEC_diffie_hellman_agree_ioctl = NULL;
static t_UBSEC_rsa_mod_exp_ioctl *p_UBSEC_rsa_mod_exp_ioctl = NULL;
static t_UBSEC_rsa_mod_exp_crt_ioctl *p_UBSEC_rsa_mod_exp_crt_ioctl = NULL;
static t_UBSEC_dsa_sign_ioctl *p_UBSEC_dsa_sign_ioctl = NULL;
static t_UBSEC_dsa_verify_ioctl *p_UBSEC_dsa_verify_ioctl = NULL;
static t_UBSEC_math_accelerate_ioctl *p_UBSEC_math_accelerate_ioctl = NULL;
static t_UBSEC_rng_ioctl *p_UBSEC_rng_ioctl = NULL;

/* 
 * These are the static string constants for the DSO file name and the function
 * symbol names to bind to. 
 */

static const char *UBSEC_LIBNAME = "ubsec";
static const char *UBSEC_F1 = "ubsec_bytes_to_bits";
static const char *UBSEC_F2 = "ubsec_bits_to_bytes";
static const char *UBSEC_F3 = "ubsec_open";
static const char *UBSEC_F4 = "ubsec_close";
static const char *UBSEC_F5 = "diffie_hellman_generate_ioctl";
static const char *UBSEC_F6 = "diffie_hellman_agree_ioctl";
static const char *UBSEC_F7 = "rsa_mod_exp_ioctl";
static const char *UBSEC_F8 = "rsa_mod_exp_crt_ioctl";
static const char *UBSEC_F9 = "dsa_sign_ioctl";
static const char *UBSEC_F10 = "dsa_verify_ioctl";
static const char *UBSEC_F11 = "math_accelerate_ioctl";
static const char *UBSEC_F12 = "rng_ioctl";

/* (de)initialisation functions. */
static int ubsec_init(ENGINE *e)
	{
	t_UBSEC_ubsec_bytes_to_bits *p1;
	t_UBSEC_ubsec_bits_to_bytes *p2;
	t_UBSEC_ubsec_open *p3;
	t_UBSEC_ubsec_close *p4;
	t_UBSEC_diffie_hellman_generate_ioctl *p5;
	t_UBSEC_diffie_hellman_agree_ioctl *p6;
	t_UBSEC_rsa_mod_exp_ioctl *p7;
	t_UBSEC_rsa_mod_exp_crt_ioctl *p8;
	t_UBSEC_dsa_sign_ioctl *p9;
	t_UBSEC_dsa_verify_ioctl *p10;
	t_UBSEC_math_accelerate_ioctl *p11;
	t_UBSEC_rng_ioctl *p12;
	int fd = 0;

	if(ubsec_dso != NULL)
		{
		ENGINEerr(ENGINE_F_UBSEC_INIT, ENGINE_R_ALREADY_LOADED);
		goto err;
		}
	/* 
	 * Attempt to load libubsec.so/ubsec.dll/whatever. 
	 */
	ubsec_dso = DSO_load(NULL, UBSEC_LIBNAME, NULL, 0);
	if(ubsec_dso == NULL)
		{
		ENGINEerr(ENGINE_F_UBSEC_INIT, ENGINE_R_DSO_FAILURE);
		goto err;
		}

	if (
	!(p1 = (t_UBSEC_ubsec_bytes_to_bits *) DSO_bind_func(ubsec_dso, UBSEC_F1)) ||
	!(p2 = (t_UBSEC_ubsec_bits_to_bytes *) DSO_bind_func(ubsec_dso, UBSEC_F2)) ||
	!(p3 = (t_UBSEC_ubsec_open *) DSO_bind_func(ubsec_dso, UBSEC_F3)) ||
	!(p4 = (t_UBSEC_ubsec_close *) DSO_bind_func(ubsec_dso, UBSEC_F4)) ||
	!(p5 = (t_UBSEC_diffie_hellman_generate_ioctl *) 
				DSO_bind_func(ubsec_dso, UBSEC_F5)) ||
	!(p6 = (t_UBSEC_diffie_hellman_agree_ioctl *) 
				DSO_bind_func(ubsec_dso, UBSEC_F6)) ||
	!(p7 = (t_UBSEC_rsa_mod_exp_ioctl *) DSO_bind_func(ubsec_dso, UBSEC_F7)) ||
	!(p8 = (t_UBSEC_rsa_mod_exp_crt_ioctl *) DSO_bind_func(ubsec_dso, UBSEC_F8)) ||
	!(p9 = (t_UBSEC_dsa_sign_ioctl *) DSO_bind_func(ubsec_dso, UBSEC_F9)) ||
	!(p10 = (t_UBSEC_dsa_verify_ioctl *) DSO_bind_func(ubsec_dso, UBSEC_F10)) ||
	!(p11 = (t_UBSEC_math_accelerate_ioctl *) 
				DSO_bind_func(ubsec_dso, UBSEC_F11)) ||
	!(p12 = (t_UBSEC_rng_ioctl *) DSO_bind_func(ubsec_dso, UBSEC_F12)))
		{
		ENGINEerr(ENGINE_F_UBSEC_INIT, ENGINE_R_DSO_FAILURE);
		goto err;
		}

	/* Copy the pointers */
	p_UBSEC_ubsec_bytes_to_bits = p1;
	p_UBSEC_ubsec_bits_to_bytes = p2;
	p_UBSEC_ubsec_open = p3;
	p_UBSEC_ubsec_close = p4;
	p_UBSEC_diffie_hellman_generate_ioctl = p5;
	p_UBSEC_diffie_hellman_agree_ioctl = p6;
	p_UBSEC_rsa_mod_exp_ioctl = p7;
	p_UBSEC_rsa_mod_exp_crt_ioctl = p8;
	p_UBSEC_dsa_sign_ioctl = p9;
	p_UBSEC_dsa_verify_ioctl = p10;
	p_UBSEC_math_accelerate_ioctl = p11;
	p_UBSEC_rng_ioctl = p12;

	/* Perform an open to see if there's actually any unit running. */
	if ((fd = p_UBSEC_ubsec_open(UBSEC_KEY_DEVICE_NAME)) > 0)
		{
		p_UBSEC_ubsec_close(fd);
		return 1;
		}
	else
		{
		ENGINEerr(ENGINE_F_UBSEC_INIT, ENGINE_R_UNIT_FAILURE);
		}

err:
	if(ubsec_dso)
		DSO_free(ubsec_dso);
	p_UBSEC_ubsec_bytes_to_bits = NULL;
	p_UBSEC_ubsec_bits_to_bytes = NULL;
	p_UBSEC_ubsec_open = NULL;
	p_UBSEC_ubsec_close = NULL;
	p_UBSEC_diffie_hellman_generate_ioctl = NULL;
	p_UBSEC_diffie_hellman_agree_ioctl = NULL;
	p_UBSEC_rsa_mod_exp_ioctl = NULL;
	p_UBSEC_rsa_mod_exp_crt_ioctl = NULL;
	p_UBSEC_dsa_sign_ioctl = NULL;
	p_UBSEC_dsa_verify_ioctl = NULL;
	p_UBSEC_math_accelerate_ioctl = NULL;
	p_UBSEC_rng_ioctl = NULL;

	return 0;
	}

static int ubsec_finish(ENGINE *e)
	{
	if(ubsec_dso == NULL)
		{
		ENGINEerr(ENGINE_F_UBSEC_FINISH, ENGINE_R_NOT_LOADED);
		return 0;
		}
	if(!DSO_free(ubsec_dso))
		{
		ENGINEerr(ENGINE_F_UBSEC_FINISH, ENGINE_R_DSO_FAILURE);
		return 0;
		}
	ubsec_dso = NULL;
	p_UBSEC_ubsec_bytes_to_bits = NULL;
	p_UBSEC_ubsec_bits_to_bytes = NULL;
	p_UBSEC_ubsec_open = NULL;
	p_UBSEC_ubsec_close = NULL;
	p_UBSEC_diffie_hellman_generate_ioctl = NULL;
	p_UBSEC_diffie_hellman_agree_ioctl = NULL;
	p_UBSEC_rsa_mod_exp_ioctl = NULL;
	p_UBSEC_rsa_mod_exp_crt_ioctl = NULL;
	p_UBSEC_dsa_sign_ioctl = NULL;
	p_UBSEC_dsa_verify_ioctl = NULL;
	p_UBSEC_math_accelerate_ioctl = NULL;
	p_UBSEC_rng_ioctl = NULL;
	return 1;
	}

static int ubsec_mod_exp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
		const BIGNUM *m, BN_CTX *ctx)
	{
	int 	y_len = 0;
	int 	fd;

	if(ubsec_dso == NULL)
	{
		ENGINEerr(ENGINE_F_UBSEC_MOD_EXP, ENGINE_R_NOT_LOADED);
		return 0;
	}

	/* Check if hardware can't handle this argument. */
	y_len = BN_num_bits(m);
	if (y_len > 1024) {
		ENGINEerr(ENGINE_F_UBSEC_MOD_EXP, ENGINE_R_SIZE_TOO_LARGE_OR_TOO_SMALL);
		return 0;
	} 

	if(!bn_wexpand(r, m->top))
	{
		ENGINEerr(ENGINE_F_UBSEC_MOD_EXP, ENGINE_R_BN_EXPAND_FAIL);
		return 0;
	}
	memset(r->d, 0, BN_num_bytes(m));

	if ((fd = p_UBSEC_ubsec_open(UBSEC_KEY_DEVICE_NAME)) <= 0) {
		fd = 0;
		ENGINEerr(ENGINE_F_UBSEC_INIT, ENGINE_R_UNIT_FAILURE);
		return 0;
	}

	if (p_UBSEC_rsa_mod_exp_ioctl(fd, (unsigned char *)a->d, BN_num_bits(a),
		(unsigned char *)m->d, BN_num_bits(m), (unsigned char *)p->d, 
		BN_num_bits(p), (unsigned char *)r->d, &y_len) != 0)
	{
		ENGINEerr(ENGINE_F_UBSEC_MOD_EXP, ENGINE_R_REQUEST_FAILED);
		return 0;
	}

	p_UBSEC_ubsec_close(fd);

	r->top = (BN_num_bits(m)+BN_BITS2-1)/BN_BITS2;
	return 1;
	}

static int ubsec_rsa_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa)
	{
	BN_CTX *ctx;
	int to_return = 0;

	if((ctx = BN_CTX_new()) == NULL)
		goto err;

	if(!rsa->p || !rsa->q || !rsa->dmp1 || !rsa->dmq1 || !rsa->iqmp)
		{
		ENGINEerr(ENGINE_F_UBSEC_RSA_MOD_EXP, ENGINE_R_MISSING_KEY_COMPONENTS);
		goto err;
		}

	/*
	 * Do in software if argument is too large for hardware.
	 */
	if ((BN_num_bits(rsa->p)+BN_num_bits(rsa->q)) > 1024) {
		const RSA_METHOD *meth = RSA_PKCS1_SSLeay();
		to_return = (*meth->rsa_mod_exp)(r0, I, rsa);
	} else {
		to_return = ubsec_mod_exp_crt(r0, I, rsa->p, rsa->q, rsa->dmp1,
			rsa->dmq1, rsa->iqmp, ctx);
	}
err:
	if(ctx)
		BN_CTX_free(ctx);
	return to_return;
	}

static int ubsec_mod_exp_crt(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
			const BIGNUM *q, const BIGNUM *dp,
			const BIGNUM *dq, const BIGNUM *qinv, BN_CTX *ctx)
	{
	int	y_len,
		m_len,
		fd;

	m_len = BN_num_bytes(p) + BN_num_bytes(q) + 1;
	y_len = BN_num_bits(p) + BN_num_bits(q);

	/* Check if hardware can't handle this argument. */
	if (y_len > 1024) {
		ENGINEerr(ENGINE_F_UBSEC_MOD_EXP, ENGINE_R_SIZE_TOO_LARGE_OR_TOO_SMALL);
		return 0;
	} 

	if (!bn_wexpand(r, p->top + q->top + 1)) {
		ENGINEerr(ENGINE_F_UBSEC_RSA_MOD_EXP_CRT, ENGINE_R_BN_EXPAND_FAIL);
		return 0;
	}

	if ((fd = p_UBSEC_ubsec_open(UBSEC_KEY_DEVICE_NAME)) <= 0) {
		fd = 0;
		ENGINEerr(ENGINE_F_UBSEC_INIT, ENGINE_R_UNIT_FAILURE);
		return 0;
	}

	if (p_UBSEC_rsa_mod_exp_crt_ioctl(fd,
		(unsigned char *)a->d, BN_num_bits(a), 
		(unsigned char *)qinv->d, BN_num_bits(qinv),
		(unsigned char *)dp->d, BN_num_bits(dp),
		(unsigned char *)p->d, BN_num_bits(p),
		(unsigned char *)dq->d, BN_num_bits(dq),
		(unsigned char *)q->d, BN_num_bits(q),
		(unsigned char *)r->d,  &y_len) != 0) {
		ENGINEerr(ENGINE_F_UBSEC_MOD_EXP, ENGINE_R_REQUEST_FAILED);
		return 0;
	}

	p_UBSEC_ubsec_close(fd);

	r->top = (BN_num_bits(p) + BN_num_bits(q) + BN_BITS2 - 1)/BN_BITS2;
	return 1;
}

#if NOT_USED
static int ubsec_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 (!ubsec_mod_exp(rr,a1,p1,m,ctx)) goto end;
	/* let t = a2 ^ p2 mod m */
	if (!ubsec_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 ubsec_mod_exp_dsa(DSA *dsa, BIGNUM *r, BIGNUM *a,
		const BIGNUM *p, const BIGNUM *m, BN_CTX *ctx,
		BN_MONT_CTX *m_ctx)
	{
	return ubsec_mod_exp(r, a, p, m, ctx);
	}
#endif

/*
 * This function is aliased to mod_exp (with the mont stuff dropped).
 */
static int ubsec_mod_exp_mont(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
		const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx)
{
	int ret = 0;

 	/* Do in software if the key is too large for the hardware. */
	if (BN_num_bits(m) > 1024) {
		const RSA_METHOD *meth = RSA_PKCS1_SSLeay();
		ret = (*meth->bn_mod_exp)(r, a, p, m, ctx, m_ctx);
	} else {
		ret = ubsec_mod_exp(r, a, p, m, ctx);
	}
	
	return ret;
}

/* This function is aliased to mod_exp (with the dh and mont dropped). */
static int ubsec_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 ubsec_mod_exp(r, a, p, m, ctx);
	}

static DSA_SIG *ubsec_dsa_do_sign(const unsigned char *dgst, int dlen, DSA *dsa)
	{
	DSA_SIG *to_return = NULL;
	int s_len = 160, r_len = 160, d_len, fd;
	BIGNUM m, *r=NULL, *s=NULL;

	BN_init(&m);

	s = BN_new();
	r = BN_new();
	if ((s == NULL) || (r==NULL))
		goto err;

	d_len = p_UBSEC_ubsec_bytes_to_bits((unsigned char *)dgst, dlen);

        if(!bn_wexpand(r, (160+BN_BITS2-1)/BN_BITS2) ||
       	   (!bn_wexpand(s, (160+BN_BITS2-1)/BN_BITS2))) {
		ENGINEerr(ENGINE_F_UBSEC_DSA_SIGN, ENGINE_R_BN_EXPAND_FAIL);
		goto err;
	}

	if (BN_bin2bn(dgst,dlen,&m) == NULL) {
		ENGINEerr(ENGINE_F_UBSEC_DSA_SIGN, ENGINE_R_BN_EXPAND_FAIL);
		goto err;
	} 

	if ((fd = p_UBSEC_ubsec_open(UBSEC_KEY_DEVICE_NAME)) <= 0) {
		fd = 0;
		ENGINEerr(ENGINE_F_UBSEC_INIT, ENGINE_R_UNIT_FAILURE);
		return 0;
	}

	if (p_UBSEC_dsa_sign_ioctl(fd, 0, /* compute hash before signing */
		(unsigned char *)dgst, d_len,
		NULL, 0,  /* compute random value */
		(unsigned char *)dsa->p->d, BN_num_bits(dsa->p), 
		(unsigned char *)dsa->q->d, BN_num_bits(dsa->q),
		(unsigned char *)dsa->g->d, BN_num_bits(dsa->g),
		(unsigned char *)dsa->priv_key->d, BN_num_bits(dsa->priv_key),
		(unsigned char *)r->d, &r_len,
		(unsigned char *)s->d, &s_len ) != 0) {
		ENGINEerr(ENGINE_F_UBSEC_DSA_SIGN, ENGINE_R_REQUEST_FAILED);
		goto err;
	}

	p_UBSEC_ubsec_close(fd);

	r->top = (160+BN_BITS2-1)/BN_BITS2;
	s->top = (160+BN_BITS2-1)/BN_BITS2;

	to_return = DSA_SIG_new();
	if(to_return == NULL) {
		ENGINEerr(ENGINE_F_UBSEC_DSA_SIGN, ENGINE_R_BN_EXPAND_FAIL);
		goto err;
	}

	to_return->r = r;
	to_return->s = s;

err:
	if (!to_return) {
		if (r) BN_free(r);
		if (s) BN_free(s);
	}                                 
	BN_clear_free(&m);
	return to_return;
}

static int ubsec_dsa_verify(const unsigned char *dgst, int dgst_len,
                                DSA_SIG *sig, DSA *dsa)
	{
	int v_len, d_len;
	int to_return = 0;
	int fd;
	BIGNUM v;

	BN_init(&v);

	if(!bn_wexpand(&v, dsa->p->top)) {
		ENGINEerr(ENGINE_F_UBSEC_DSA_VERIFY ,ENGINE_R_BN_EXPAND_FAIL);
		goto err;
	}

	v_len = BN_num_bits(dsa->p);

	d_len = p_UBSEC_ubsec_bytes_to_bits((unsigned char *)dgst, dgst_len);

	if ((fd = p_UBSEC_ubsec_open(UBSEC_KEY_DEVICE_NAME)) <= 0) {
		fd = 0;
		ENGINEerr(ENGINE_F_UBSEC_INIT, ENGINE_R_UNIT_FAILURE);
		return 0;
	}

	if (p_UBSEC_dsa_verify_ioctl(fd, 0, /* compute hash before signing */
		(unsigned char *)dgst, d_len,
		(unsigned char *)dsa->p->d, BN_num_bits(dsa->p), 
		(unsigned char *)dsa->q->d, BN_num_bits(dsa->q),
		(unsigned char *)dsa->g->d, BN_num_bits(dsa->g),
		(unsigned char *)dsa->pub_key->d, BN_num_bits(dsa->pub_key),
		(unsigned char *)sig->r->d, BN_num_bits(sig->r),
		(unsigned char *)sig->s->d, BN_num_bits(sig->s),
		(unsigned char *)v.d, &v_len) != 0) {
		ENGINEerr(ENGINE_F_UBSEC_DSA_VERIFY , ENGINE_R_REQUEST_FAILED);
		goto err;
	}

	p_UBSEC_ubsec_close(fd);

	to_return = 1;
err:
	BN_clear_free(&v);
	return to_return;
	}

static int ubsec_dh_compute_key (unsigned char *key,const BIGNUM *pub_key,DH *dh)
	{
	return 0;
	}

static int ubsec_dh_generate_key (DH *dh)
	{
	return 0;
	}

#ifdef NOT_USED
static int ubsec_rand_bytes(unsigned char *buf, int num)
	{
	return 0;
	}

static int ubsec_rand_status(void)
	{
	return 0;
	}
#endif

#endif /* !OPENSSL_NO_HW_UBSEC */
#endif /* !OPENSSL_NO_HW */