eng_cryptodev.c

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/*
 * Copyright (c) 2002 Bob Beck <[email protected]>
 * Copyright (c) 2002 Theo de Raadt
 * Copyright (c) 2002 Markus Friedl
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 THE AUTHOR OR 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.
 *
 */

#include <openssl/objects.h>
#include <openssl/engine.h>
#include <openssl/evp.h>
#include <openssl/bn.h>

#if (defined(__unix__) || defined(unix)) && !defined(USG) && \
    (defined(OpenBSD) || defined(__FreeBSD__))
#include <sys/param.h>
# if (OpenBSD >= 200112) || ((__FreeBSD_version >= 470101 && __FreeBSD_version < 500000) || __FreeBSD_version >= 500041)
#  define HAVE_CRYPTODEV
# endif
# if (OpenBSD >= 200110)
#  define HAVE_SYSLOG_R
# endif
#endif

#ifndef HAVE_CRYPTODEV

void
ENGINE_load_cryptodev(void)
{
    /* This is a NOP on platforms without /dev/crypto */
    return;
}

#else 
 
#include <sys/types.h>
#include <crypto/cryptodev.h>
#include <crypto/dh/dh.h>
#include <crypto/dsa/dsa.h>
#include <crypto/err/err.h>
#include <crypto/rsa/rsa.h>
#include <sys/ioctl.h>
#include <errno.h>
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdarg.h>
#include <syslog.h>
#include <errno.h>
#include <string.h>

struct dev_crypto_state {
    struct session_op d_sess;
    int d_fd;

#ifdef USE_CRYPTODEV_DIGESTS
    char dummy_mac_key[HASH_MAX_LEN];

    unsigned char digest_res[HASH_MAX_LEN];
    char *mac_data;
    int mac_len;
#endif
};

static u_int32_t cryptodev_asymfeat = 0;

static int get_asym_dev_crypto(void);
static int open_dev_crypto(void);
static int get_dev_crypto(void);
static int get_cryptodev_ciphers(const int **cnids);
#ifdef USE_CRYPTODEV_DIGESTS
static int get_cryptodev_digests(const int **cnids);
#endif
static int cryptodev_usable_ciphers(const int **nids);
static int cryptodev_usable_digests(const int **nids);
static int cryptodev_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
    const unsigned char *in, size_t inl);
static int cryptodev_init_key(EVP_CIPHER_CTX *ctx, const unsigned char *key,
    const unsigned char *iv, int enc);
static int cryptodev_cleanup(EVP_CIPHER_CTX *ctx);
static int cryptodev_engine_ciphers(ENGINE *e, const EVP_CIPHER **cipher,
    const int **nids, int nid);
static int cryptodev_engine_digests(ENGINE *e, const EVP_MD **digest,
    const int **nids, int nid);
static int bn2crparam(const BIGNUM *a, struct crparam *crp);
static int crparam2bn(struct crparam *crp, BIGNUM *a);
static void zapparams(struct crypt_kop *kop);
static int cryptodev_asym(struct crypt_kop *kop, int rlen, BIGNUM *r,
    int slen, BIGNUM *s);

static int cryptodev_bn_mod_exp(BIGNUM *r, const BIGNUM *a,
    const BIGNUM *p, const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx);
static int cryptodev_rsa_nocrt_mod_exp(BIGNUM *r0, const BIGNUM *I,
    RSA *rsa, BN_CTX *ctx);
static int cryptodev_rsa_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx);
static int cryptodev_dsa_bn_mod_exp(DSA *dsa, BIGNUM *r, BIGNUM *a,
    const BIGNUM *p, const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx);
static int cryptodev_dsa_dsa_mod_exp(DSA *dsa, BIGNUM *t1, BIGNUM *g,
    BIGNUM *u1, BIGNUM *pub_key, BIGNUM *u2, BIGNUM *p,
    BN_CTX *ctx, BN_MONT_CTX *mont);
static DSA_SIG *cryptodev_dsa_do_sign(const unsigned char *dgst,
    int dlen, DSA *dsa);
static int cryptodev_dsa_verify(const unsigned char *dgst, int dgst_len,
    DSA_SIG *sig, DSA *dsa);
static int cryptodev_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 cryptodev_dh_compute_key(unsigned char *key,
    const BIGNUM *pub_key, DH *dh);
static int cryptodev_ctrl(ENGINE *e, int cmd, long i, void *p,
    void (*f)(void));
void ENGINE_load_cryptodev(void);

static const ENGINE_CMD_DEFN cryptodev_defns[] = {
    { 0, NULL, NULL, 0 }
};

static struct {
    int id;
    int nid;
    int ivmax;
    int keylen;
} ciphers[] = {
    { CRYPTO_ARC4,          NID_rc4,        0,  16, },
    { CRYPTO_DES_CBC,       NID_des_cbc,        8,   8, },
    { CRYPTO_3DES_CBC,      NID_des_ede3_cbc,   8,  24, },
    { CRYPTO_AES_CBC,       NID_aes_128_cbc,    16, 16, },
    { CRYPTO_AES_CBC,       NID_aes_192_cbc,    16, 24, },
    { CRYPTO_AES_CBC,       NID_aes_256_cbc,    16, 32, },
    { CRYPTO_BLF_CBC,       NID_bf_cbc,     8,  16, },
    { CRYPTO_CAST_CBC,      NID_cast5_cbc,      8,  16, },
    { CRYPTO_SKIPJACK_CBC,      NID_undef,      0,   0, },
    { 0,                NID_undef,      0,   0, },
};

#ifdef USE_CRYPTODEV_DIGESTS
static struct {
    int id;
    int nid;
    int     keylen;
} digests[] = {
    { CRYPTO_MD5_HMAC,      NID_hmacWithMD5,    16},
    { CRYPTO_SHA1_HMAC,     NID_hmacWithSHA1,   20},
    { CRYPTO_RIPEMD160_HMAC,    NID_ripemd160,      16/*?*/},
    { CRYPTO_MD5_KPDK,      NID_undef,      0},
    { CRYPTO_SHA1_KPDK,     NID_undef,      0},
    { CRYPTO_MD5,           NID_md5,        16},
    { CRYPTO_SHA1,          NID_sha1,       20},
    { 0,                NID_undef,      0},
};
#endif

/*
 * Return a fd if /dev/crypto seems usable, 0 otherwise.
 */
static int
open_dev_crypto(void)
{
    static int fd = -1;

    if (fd == -1) {
        if ((fd = open("/dev/crypto", O_RDWR, 0)) == -1)
            return (-1);
        /* close on exec */
        if (fcntl(fd, F_SETFD, 1) == -1) {
            close(fd);
            fd = -1;
            return (-1);
        }
    }
    return (fd);
}

static int
get_dev_crypto(void)
{
    int fd, retfd;

    if ((fd = open_dev_crypto()) == -1)
        return (-1);
#ifndef CRIOGET_NOT_NEEDED
    if (ioctl(fd, CRIOGET, &retfd) == -1)
        return (-1);

    /* close on exec */
    if (fcntl(retfd, F_SETFD, 1) == -1) {
        close(retfd);
        return (-1);
    }
#else
        retfd = fd;
#endif
    return (retfd);
}

static void put_dev_crypto(int fd)
{
#ifndef CRIOGET_NOT_NEEDED
    close(fd);
#endif
}

/* Caching version for asym operations */
static int
get_asym_dev_crypto(void)
{
    static int fd = -1;

    if (fd == -1)
        fd = get_dev_crypto();
    return fd;
}

/*
 * Find out what ciphers /dev/crypto will let us have a session for.
 * XXX note, that some of these openssl doesn't deal with yet!
 * returning them here is harmless, as long as we return NULL
 * when asked for a handler in the cryptodev_engine_ciphers routine
 */
static int
get_cryptodev_ciphers(const int **cnids)
{
    static int nids[CRYPTO_ALGORITHM_MAX];
    struct session_op sess;
    int fd, i, count = 0;

    if ((fd = get_dev_crypto()) < 0) {
        *cnids = NULL;
        return (0);
    }
    memset(&sess, 0, sizeof(sess));
    sess.key = (caddr_t)"123456789abcdefghijklmno";

    for (i = 0; ciphers[i].id && count < CRYPTO_ALGORITHM_MAX; i++) {
        if (ciphers[i].nid == NID_undef)
            continue;
        sess.cipher = ciphers[i].id;
        sess.keylen = ciphers[i].keylen;
        sess.mac = 0;
        if (ioctl(fd, CIOCGSESSION, &sess) != -1 &&
            ioctl(fd, CIOCFSESSION, &sess.ses) != -1)
            nids[count++] = ciphers[i].nid;
    }
    put_dev_crypto(fd);

    if (count > 0)
        *cnids = nids;
    else
        *cnids = NULL;
    return (count);
}

#ifdef USE_CRYPTODEV_DIGESTS
/*
 * Find out what digests /dev/crypto will let us have a session for.
 * XXX note, that some of these openssl doesn't deal with yet!
 * returning them here is harmless, as long as we return NULL
 * when asked for a handler in the cryptodev_engine_digests routine
 */
static int
get_cryptodev_digests(const int **cnids)
{
    static int nids[CRYPTO_ALGORITHM_MAX];
    struct session_op sess;
    int fd, i, count = 0;

    if ((fd = get_dev_crypto()) < 0) {
        *cnids = NULL;
        return (0);
    }
    memset(&sess, 0, sizeof(sess));
    sess.mackey = (caddr_t)"123456789abcdefghijklmno";
    for (i = 0; digests[i].id && count < CRYPTO_ALGORITHM_MAX; i++) {
        if (digests[i].nid == NID_undef)
            continue;
        sess.mac = digests[i].id;
        sess.mackeylen = digests[i].keylen;
        sess.cipher = 0;
        if (ioctl(fd, CIOCGSESSION, &sess) != -1 &&
            ioctl(fd, CIOCFSESSION, &sess.ses) != -1)
            nids[count++] = digests[i].nid;
    }
    put_dev_crypto(fd);

    if (count > 0)
        *cnids = nids;
    else
        *cnids = NULL;
    return (count);
}
#endif  /* 0 */

/*
 * Find the useable ciphers|digests from dev/crypto - this is the first
 * thing called by the engine init crud which determines what it
 * can use for ciphers from this engine. We want to return
 * only what we can do, anythine else is handled by software.
 *
 * If we can't initialize the device to do anything useful for
 * any reason, we want to return a NULL array, and 0 length,
 * which forces everything to be done is software. By putting
 * the initalization of the device in here, we ensure we can
 * use this engine as the default, and if for whatever reason
 * /dev/crypto won't do what we want it will just be done in
 * software
 *
 * This can (should) be greatly expanded to perhaps take into
 * account speed of the device, and what we want to do.
 * (although the disabling of particular alg's could be controlled
 * by the device driver with sysctl's.) - this is where we
 * want most of the decisions made about what we actually want
 * to use from /dev/crypto.
 */
static int
cryptodev_usable_ciphers(const int **nids)
{
    return (get_cryptodev_ciphers(nids));
}

static int
cryptodev_usable_digests(const int **nids)
{
#ifdef USE_CRYPTODEV_DIGESTS
    return (get_cryptodev_digests(nids));
#else
    /*
     * XXXX just disable all digests for now, because it sucks.
     * we need a better way to decide this - i.e. I may not
     * want digests on slow cards like hifn on fast machines,
     * but might want them on slow or loaded machines, etc.
     * will also want them when using crypto cards that don't
     * suck moose gonads - would be nice to be able to decide something
     * as reasonable default without having hackery that's card dependent.
     * of course, the default should probably be just do everything,
     * with perhaps a sysctl to turn algoritms off (or have them off
     * by default) on cards that generally suck like the hifn.
     */
    *nids = NULL;
    return (0);
#endif
}

static int
cryptodev_cipher(EVP_CIPHER_CTX *ctx, unsigned char *out,
    const unsigned char *in, size_t inl)
{
    struct crypt_op cryp;
    struct dev_crypto_state *state = ctx->cipher_data;
    struct session_op *sess = &state->d_sess;
    const void *iiv;
    unsigned char save_iv[EVP_MAX_IV_LENGTH];

    if (state->d_fd < 0)
        return (0);
    if (!inl)
        return (1);
    if ((inl % ctx->cipher->block_size) != 0)
        return (0);

    memset(&cryp, 0, sizeof(cryp));

    cryp.ses = sess->ses;
    cryp.flags = 0;
    cryp.len = inl;
    cryp.src = (caddr_t) in;
    cryp.dst = (caddr_t) out;
    cryp.mac = 0;

    cryp.op = ctx->encrypt ? COP_ENCRYPT : COP_DECRYPT;

    if (ctx->cipher->iv_len) {
        cryp.iv = (caddr_t) ctx->iv;
        if (!ctx->encrypt) {
            iiv = in + inl - ctx->cipher->iv_len;
            memcpy(save_iv, iiv, ctx->cipher->iv_len);
        }
    } else
        cryp.iv = NULL;

    if (ioctl(state->d_fd, CIOCCRYPT, &cryp) == -1) {
        /* XXX need better errror handling
         * this can fail for a number of different reasons.
         */
        return (0);
    }

    if (ctx->cipher->iv_len) {
        if (ctx->encrypt)
            iiv = out + inl - ctx->cipher->iv_len;
        else
            iiv = save_iv;
        memcpy(ctx->iv, iiv, ctx->cipher->iv_len);
    }
    return (1);
}

static int
cryptodev_init_key(EVP_CIPHER_CTX *ctx, const unsigned char *key,
    const unsigned char *iv, int enc)
{
    struct dev_crypto_state *state = ctx->cipher_data;
    struct session_op *sess = &state->d_sess;
    int cipher = -1, i;

    for (i = 0; ciphers[i].id; i++)
        if (ctx->cipher->nid == ciphers[i].nid &&
            ctx->cipher->iv_len <= ciphers[i].ivmax &&
            ctx->key_len == ciphers[i].keylen) {
            cipher = ciphers[i].id;
            break;
        }

    if (!ciphers[i].id) {
        state->d_fd = -1;
        return (0);
    }

    memset(sess, 0, sizeof(struct session_op));

    if ((state->d_fd = get_dev_crypto()) < 0)
        return (0);

    sess->key = (caddr_t)key;
    sess->keylen = ctx->key_len;
    sess->cipher = cipher;

    if (ioctl(state->d_fd, CIOCGSESSION, sess) == -1) {
        put_dev_crypto(state->d_fd);
        state->d_fd = -1;
        return (0);
    }
    return (1);
}

/*
 * free anything we allocated earlier when initting a
 * session, and close the session.
 */
static int
cryptodev_cleanup(EVP_CIPHER_CTX *ctx)
{
    int ret = 0;
    struct dev_crypto_state *state = ctx->cipher_data;
    struct session_op *sess = &state->d_sess;

    if (state->d_fd < 0)
        return (0);

    /* XXX if this ioctl fails, someting's wrong. the invoker
     * may have called us with a bogus ctx, or we could
     * have a device that for whatever reason just doesn't
     * want to play ball - it's not clear what's right
     * here - should this be an error? should it just
     * increase a counter, hmm. For right now, we return
     * 0 - I don't believe that to be "right". we could
     * call the gorpy openssl lib error handlers that
     * print messages to users of the library. hmm..
     */

    if (ioctl(state->d_fd, CIOCFSESSION, &sess->ses) == -1) {
        ret = 0;
    } else {
        ret = 1;
    }
    put_dev_crypto(state->d_fd);
    state->d_fd = -1;

    return (ret);
}

/*
 * libcrypto EVP stuff - this is how we get wired to EVP so the engine
 * gets called when libcrypto requests a cipher NID.
 */

/* RC4 */
const EVP_CIPHER cryptodev_rc4 = {
    NID_rc4,
    1, 16, 0,
    EVP_CIPH_VARIABLE_LENGTH,
    cryptodev_init_key,
    cryptodev_cipher,
    cryptodev_cleanup,
    sizeof(struct dev_crypto_state),
    NULL,
    NULL,
    NULL
};

/* DES CBC EVP */
const EVP_CIPHER cryptodev_des_cbc = {
    NID_des_cbc,
    8, 8, 8,
    EVP_CIPH_CBC_MODE,
    cryptodev_init_key,
    cryptodev_cipher,
    cryptodev_cleanup,
    sizeof(struct dev_crypto_state),
    EVP_CIPHER_set_asn1_iv,
    EVP_CIPHER_get_asn1_iv,
    NULL
};

/* 3DES CBC EVP */
const EVP_CIPHER cryptodev_3des_cbc = {
    NID_des_ede3_cbc,
    8, 24, 8,
    EVP_CIPH_CBC_MODE,
    cryptodev_init_key,
    cryptodev_cipher,
    cryptodev_cleanup,
    sizeof(struct dev_crypto_state),
    EVP_CIPHER_set_asn1_iv,
    EVP_CIPHER_get_asn1_iv,
    NULL
};

const EVP_CIPHER cryptodev_bf_cbc = {
    NID_bf_cbc,
    8, 16, 8,
    EVP_CIPH_CBC_MODE,
    cryptodev_init_key,
    cryptodev_cipher,
    cryptodev_cleanup,
    sizeof(struct dev_crypto_state),
    EVP_CIPHER_set_asn1_iv,
    EVP_CIPHER_get_asn1_iv,
    NULL
};

const EVP_CIPHER cryptodev_cast_cbc = {
    NID_cast5_cbc,
    8, 16, 8,
    EVP_CIPH_CBC_MODE,
    cryptodev_init_key,
    cryptodev_cipher,
    cryptodev_cleanup,
    sizeof(struct dev_crypto_state),
    EVP_CIPHER_set_asn1_iv,
    EVP_CIPHER_get_asn1_iv,
    NULL
};

const EVP_CIPHER cryptodev_aes_cbc = {
    NID_aes_128_cbc,
    16, 16, 16,
    EVP_CIPH_CBC_MODE,
    cryptodev_init_key,
    cryptodev_cipher,
    cryptodev_cleanup,
    sizeof(struct dev_crypto_state),
    EVP_CIPHER_set_asn1_iv,
    EVP_CIPHER_get_asn1_iv,
    NULL
};

const EVP_CIPHER cryptodev_aes_192_cbc = {
    NID_aes_192_cbc,
    16, 24, 16,
    EVP_CIPH_CBC_MODE,
    cryptodev_init_key,
    cryptodev_cipher,
    cryptodev_cleanup,
    sizeof(struct dev_crypto_state),
    EVP_CIPHER_set_asn1_iv,
    EVP_CIPHER_get_asn1_iv,
    NULL
};

const EVP_CIPHER cryptodev_aes_256_cbc = {
    NID_aes_256_cbc,
    16, 32, 16,
    EVP_CIPH_CBC_MODE,
    cryptodev_init_key,
    cryptodev_cipher,
    cryptodev_cleanup,
    sizeof(struct dev_crypto_state),
    EVP_CIPHER_set_asn1_iv,
    EVP_CIPHER_get_asn1_iv,
    NULL
};

/*
 * Registered by the ENGINE when used to find out how to deal with
 * a particular NID in the ENGINE. this says what we'll do at the
 * top level - note, that list is restricted by what we answer with
 */
static int
cryptodev_engine_ciphers(ENGINE *e, const EVP_CIPHER **cipher,
    const int **nids, int nid)
{
    if (!cipher)
        return (cryptodev_usable_ciphers(nids));

    switch (nid) {
    case NID_rc4:
        *cipher = &cryptodev_rc4;
        break;
    case NID_des_ede3_cbc:
        *cipher = &cryptodev_3des_cbc;
        break;
    case NID_des_cbc:
        *cipher = &cryptodev_des_cbc;
        break;
    case NID_bf_cbc:
        *cipher = &cryptodev_bf_cbc;
        break;
    case NID_cast5_cbc:
        *cipher = &cryptodev_cast_cbc;
        break;
    case NID_aes_128_cbc:
        *cipher = &cryptodev_aes_cbc;
        break;
    case NID_aes_192_cbc:
        *cipher = &cryptodev_aes_192_cbc;
        break;
    case NID_aes_256_cbc:
        *cipher = &cryptodev_aes_256_cbc;
        break;
    default:
        *cipher = NULL;
        break;
    }
    return (*cipher != NULL);
}


#ifdef USE_CRYPTODEV_DIGESTS

/* convert digest type to cryptodev */
static int
digest_nid_to_cryptodev(int nid)
{
    int i;

    for (i = 0; digests[i].id; i++)
        if (digests[i].nid == nid)
            return (digests[i].id);
    return (0);
}


static int
digest_key_length(int nid)
{
    int i;

    for (i = 0; digests[i].id; i++)
        if (digests[i].nid == nid)
            return digests[i].keylen;
    return (0);
}


static int cryptodev_digest_init(EVP_MD_CTX *ctx)
{
    struct dev_crypto_state *state = ctx->md_data;
    struct session_op *sess = &state->d_sess;
    int digest;

    if ((digest = digest_nid_to_cryptodev(ctx->digest->type)) == NID_undef){
        printf("cryptodev_digest_init: Can't get digest \n");
        return (0);
    }

    memset(state, 0, sizeof(struct dev_crypto_state));

    if ((state->d_fd = get_dev_crypto()) < 0) {
        printf("cryptodev_digest_init: Can't get Dev \n");
        return (0);
    }

    sess->mackey = state->dummy_mac_key;
    sess->mackeylen = digest_key_length(ctx->digest->type);
    sess->mac = digest;

    if (ioctl(state->d_fd, CIOCGSESSION, sess) < 0) {
        put_dev_crypto(state->d_fd);
        state->d_fd = -1;
        printf("cryptodev_digest_init: Open session failed\n");
        return (0);
    }

    return (1);
}

static int cryptodev_digest_update(EVP_MD_CTX *ctx, const void *data,
        size_t count)
{
    struct crypt_op cryp;
    struct dev_crypto_state *state = ctx->md_data;
    struct session_op *sess = &state->d_sess;

    if (!data || state->d_fd < 0) {
        printf("cryptodev_digest_update: illegal inputs \n");
        return (0);
    }

    if (!count) {
        return (0);
    }

    if (!(ctx->flags & EVP_MD_CTX_FLAG_ONESHOT)) {
        /* if application doesn't support one buffer */
        state->mac_data = OPENSSL_realloc(state->mac_data, state->mac_len + count);

        if (!state->mac_data) {
            printf("cryptodev_digest_update: realloc failed\n");
            return (0);
        }

        memcpy(state->mac_data + state->mac_len, data, count);
        state->mac_len += count;
    
        return (1);
    }

    memset(&cryp, 0, sizeof(cryp));

    cryp.ses = sess->ses;
    cryp.flags = 0;
    cryp.len = count;
    cryp.src = (caddr_t) data;
    cryp.dst = NULL;
    cryp.mac = (caddr_t) state->digest_res;
    if (ioctl(state->d_fd, CIOCCRYPT, &cryp) < 0) {
        printf("cryptodev_digest_update: digest failed\n");
        return (0);
    }
    return (1);
}


static int cryptodev_digest_final(EVP_MD_CTX *ctx, unsigned char *md)
{
    struct crypt_op cryp;
    struct dev_crypto_state *state = ctx->md_data;
    struct session_op *sess = &state->d_sess;

    int ret = 1;

    if (!md || state->d_fd < 0) {
        printf("cryptodev_digest_final: illegal input\n");
        return(0);
    }

    if (! (ctx->flags & EVP_MD_CTX_FLAG_ONESHOT) ) {
        /* if application doesn't support one buffer */
        memset(&cryp, 0, sizeof(cryp));
        cryp.ses = sess->ses;
        cryp.flags = 0;
        cryp.len = state->mac_len;
        cryp.src = state->mac_data;
        cryp.dst = NULL;
        cryp.mac = (caddr_t)md;
        if (ioctl(state->d_fd, CIOCCRYPT, &cryp) < 0) {
            printf("cryptodev_digest_final: digest failed\n");
            return (0);
        }

        return 1;
    }

    memcpy(md, state->digest_res, ctx->digest->md_size);

    return (ret);
}


static int cryptodev_digest_cleanup(EVP_MD_CTX *ctx)
{
    int ret = 1;
    struct dev_crypto_state *state = ctx->md_data;
    struct session_op *sess = &state->d_sess;

    if (state == NULL)
      return 0;

    if (state->d_fd < 0) {
        printf("cryptodev_digest_cleanup: illegal input\n");
        return (0);
    }

    if (state->mac_data) {
        OPENSSL_free(state->mac_data);
        state->mac_data = NULL;
        state->mac_len = 0;
    }

    if (ioctl(state->d_fd, CIOCFSESSION, &sess->ses) < 0) {
        printf("cryptodev_digest_cleanup: failed to close session\n");
        ret = 0;
    } else {
        ret = 1;
    }
    put_dev_crypto(state->d_fd);    
    state->d_fd = -1;

    return (ret);
}

static int cryptodev_digest_copy(EVP_MD_CTX *to,const EVP_MD_CTX *from)
{
    struct dev_crypto_state *fstate = from->md_data;
    struct dev_crypto_state *dstate = to->md_data;
    struct session_op *sess;
    int digest;

    if (dstate == NULL || fstate == NULL)
      return 1;

        memcpy(dstate, fstate, sizeof(struct dev_crypto_state));

    sess = &dstate->d_sess;

    digest = digest_nid_to_cryptodev(to->digest->type);

    sess->mackey = dstate->dummy_mac_key;
    sess->mackeylen = digest_key_length(to->digest->type);
    sess->mac = digest;

    dstate->d_fd = get_dev_crypto();

    if (ioctl(dstate->d_fd, CIOCGSESSION, sess) < 0) {
        put_dev_crypto(dstate->d_fd);
        dstate->d_fd = -1;
        printf("cryptodev_digest_init: Open session failed\n");
        return (0);
    }

    if (fstate->mac_len != 0) {
            if (fstate->mac_data != NULL)
                    {
                dstate->mac_data = OPENSSL_malloc(fstate->mac_len);
                memcpy(dstate->mac_data, fstate->mac_data, fstate->mac_len);
                dstate->mac_len = fstate->mac_len;
                }
    }

    return 1;
}


const EVP_MD cryptodev_sha1 = {
    NID_sha1,
    NID_undef, 
    SHA_DIGEST_LENGTH, 
    EVP_MD_FLAG_ONESHOT,
    cryptodev_digest_init,
    cryptodev_digest_update,
    cryptodev_digest_final,
    cryptodev_digest_copy,
    cryptodev_digest_cleanup,
    EVP_PKEY_NULL_method,
    SHA_CBLOCK,
    sizeof(struct dev_crypto_state),
};

const EVP_MD cryptodev_md5 = {
    NID_md5,
    NID_undef, 
    16 /* MD5_DIGEST_LENGTH */, 
    EVP_MD_FLAG_ONESHOT,
    cryptodev_digest_init,
    cryptodev_digest_update,
    cryptodev_digest_final,
    cryptodev_digest_copy,
    cryptodev_digest_cleanup,
    EVP_PKEY_NULL_method,
    64 /* MD5_CBLOCK */,
    sizeof(struct dev_crypto_state),
};

#endif /* USE_CRYPTODEV_DIGESTS */


static int
cryptodev_engine_digests(ENGINE *e, const EVP_MD **digest,
    const int **nids, int nid)
{
    if (!digest)
        return (cryptodev_usable_digests(nids));

    switch (nid) {
#ifdef USE_CRYPTODEV_DIGESTS
    case NID_md5:
        *digest = &cryptodev_md5; 
        break;
    case NID_sha1:
        *digest = &cryptodev_sha1;
        break;
    default:
#endif /* USE_CRYPTODEV_DIGESTS */
        *digest = NULL;
        break;
    }
    return (*digest != NULL);
}

/*
 * Convert a BIGNUM to the representation that /dev/crypto needs.
 * Upon completion of use, the caller is responsible for freeing
 * crp->crp_p.
 */
static int
bn2crparam(const BIGNUM *a, struct crparam *crp)
{
    int i, j, k;
    ssize_t bytes, bits;
    u_char *b;

    crp->crp_p = NULL;
    crp->crp_nbits = 0;

    bits = BN_num_bits(a);
    bytes = (bits + 7) / 8;

    b = malloc(bytes);
    if (b == NULL)
        return (1);
    memset(b, 0, bytes);

    crp->crp_p = (caddr_t) b;
    crp->crp_nbits = bits;

    for (i = 0, j = 0; i < a->top; i++) {
        for (k = 0; k < BN_BITS2 / 8; k++) {
            if ((j + k) >= bytes)
                return (0);
            b[j + k] = a->d[i] >> (k * 8);
        }
        j += BN_BITS2 / 8;
    }
    return (0);
}

/* Convert a /dev/crypto parameter to a BIGNUM */
static int
crparam2bn(struct crparam *crp, BIGNUM *a)
{
    u_int8_t *pd;
    int i, bytes;

    bytes = (crp->crp_nbits + 7) / 8;

    if (bytes == 0)
        return (-1);

    if ((pd = (u_int8_t *) malloc(bytes)) == NULL)
        return (-1);

    for (i = 0; i < bytes; i++)
        pd[i] = crp->crp_p[bytes - i - 1];

    BN_bin2bn(pd, bytes, a);
    free(pd);

    return (0);
}

static void
zapparams(struct crypt_kop *kop)
{
    int i;

    for (i = 0; i < kop->crk_iparams + kop->crk_oparams; i++) {
        if (kop->crk_param[i].crp_p)
            free(kop->crk_param[i].crp_p);
        kop->crk_param[i].crp_p = NULL;
        kop->crk_param[i].crp_nbits = 0;
    }
}

static int
cryptodev_asym(struct crypt_kop *kop, int rlen, BIGNUM *r, int slen, BIGNUM *s)
{
    int fd, ret = -1;

    if ((fd = get_asym_dev_crypto()) < 0)
        return (ret);

    if (r) {
        kop->crk_param[kop->crk_iparams].crp_p = calloc(rlen, sizeof(char));
        kop->crk_param[kop->crk_iparams].crp_nbits = rlen * 8;
        kop->crk_oparams++;
    }
    if (s) {
        kop->crk_param[kop->crk_iparams+1].crp_p = calloc(slen, sizeof(char));
        kop->crk_param[kop->crk_iparams+1].crp_nbits = slen * 8;
        kop->crk_oparams++;
    }

    if (ioctl(fd, CIOCKEY, kop) == 0) {
        if (r)
            crparam2bn(&kop->crk_param[kop->crk_iparams], r);
        if (s)
            crparam2bn(&kop->crk_param[kop->crk_iparams+1], s);
        ret = 0;
    }

    return (ret);
}

static int
cryptodev_bn_mod_exp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
    const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *in_mont)
{
    struct crypt_kop kop;
    int ret = 1;

    /* Currently, we know we can do mod exp iff we can do any
     * asymmetric operations at all.
     */
    if (cryptodev_asymfeat == 0) {
        ret = BN_mod_exp(r, a, p, m, ctx);
        return (ret);
    }

    memset(&kop, 0, sizeof kop);
    kop.crk_op = CRK_MOD_EXP;

    /* inputs: a^p % m */
    if (bn2crparam(a, &kop.crk_param[0]))
        goto err;
    if (bn2crparam(p, &kop.crk_param[1]))
        goto err;
    if (bn2crparam(m, &kop.crk_param[2]))
        goto err;
    kop.crk_iparams = 3;

    if (cryptodev_asym(&kop, BN_num_bytes(m), r, 0, NULL)) {
        const RSA_METHOD *meth = RSA_PKCS1_SSLeay();
        printf("OCF asym process failed, Running in software\n");
        ret = meth->bn_mod_exp(r, a, p, m, ctx, in_mont);

    } else if (ECANCELED == kop.crk_status) {
        const RSA_METHOD *meth = RSA_PKCS1_SSLeay();
        printf("OCF hardware operation cancelled. Running in Software\n");
        ret = meth->bn_mod_exp(r, a, p, m, ctx, in_mont);
    }
    /* else cryptodev operation worked ok ==> ret = 1*/

err:
    zapparams(&kop);
    return (ret);
}

static int
cryptodev_rsa_nocrt_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)
{
    int r;
    ctx = BN_CTX_new();
    r = cryptodev_bn_mod_exp(r0, I, rsa->d, rsa->n, ctx, NULL);
    BN_CTX_free(ctx);
    return (r);
}

static int
cryptodev_rsa_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)
{
    struct crypt_kop kop;
    int ret = 1;

    if (!rsa->p || !rsa->q || !rsa->dmp1 || !rsa->dmq1 || !rsa->iqmp) {
        /* XXX 0 means failure?? */
        return (0);
    }

    memset(&kop, 0, sizeof kop);
    kop.crk_op = CRK_MOD_EXP_CRT;
    /* inputs: rsa->p rsa->q I rsa->dmp1 rsa->dmq1 rsa->iqmp */
    if (bn2crparam(rsa->p, &kop.crk_param[0]))
        goto err;
    if (bn2crparam(rsa->q, &kop.crk_param[1]))
        goto err;
    if (bn2crparam(I, &kop.crk_param[2]))
        goto err;
    if (bn2crparam(rsa->dmp1, &kop.crk_param[3]))
        goto err;
    if (bn2crparam(rsa->dmq1, &kop.crk_param[4]))
        goto err;
    if (bn2crparam(rsa->iqmp, &kop.crk_param[5]))
        goto err;
    kop.crk_iparams = 6;

    if (cryptodev_asym(&kop, BN_num_bytes(rsa->n), r0, 0, NULL)) {
        const RSA_METHOD *meth = RSA_PKCS1_SSLeay();
        printf("OCF asym process failed, running in Software\n");
        ret = (*meth->rsa_mod_exp)(r0, I, rsa, ctx);

    } else if (ECANCELED == kop.crk_status) {
        const RSA_METHOD *meth = RSA_PKCS1_SSLeay();
        printf("OCF hardware operation cancelled. Running in Software\n");
        ret = (*meth->rsa_mod_exp)(r0, I, rsa, ctx);
    }
    /* else cryptodev operation worked ok ==> ret = 1*/

err:
    zapparams(&kop);
    return (ret);
}

static RSA_METHOD cryptodev_rsa = {
    "cryptodev RSA method",
    NULL,               /* rsa_pub_enc */
    NULL,               /* rsa_pub_dec */
    NULL,               /* rsa_priv_enc */
    NULL,               /* rsa_priv_dec */
    NULL,
    NULL,
    NULL,               /* init */
    NULL,               /* finish */
    0,              /* flags */
    NULL,               /* app_data */
    NULL,               /* rsa_sign */
    NULL                /* rsa_verify */
};

static int
cryptodev_dsa_bn_mod_exp(DSA *dsa, BIGNUM *r, BIGNUM *a, const BIGNUM *p,
    const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx)
{
    return (cryptodev_bn_mod_exp(r, a, p, m, ctx, m_ctx));
}

static int
cryptodev_dsa_dsa_mod_exp(DSA *dsa, BIGNUM *t1, BIGNUM *g,
    BIGNUM *u1, BIGNUM *pub_key, BIGNUM *u2, BIGNUM *p,
    BN_CTX *ctx, BN_MONT_CTX *mont)
{
    BIGNUM t2;
    int ret = 0;

    BN_init(&t2);

    /* v = ( g^u1 * y^u2 mod p ) mod q */
    /* let t1 = g ^ u1 mod p */
    ret = 0;

    if (!dsa->meth->bn_mod_exp(dsa,t1,dsa->g,u1,dsa->p,ctx,mont))
        goto err;

    /* let t2 = y ^ u2 mod p */
    if (!dsa->meth->bn_mod_exp(dsa,&t2,dsa->pub_key,u2,dsa->p,ctx,mont))
        goto err;
    /* let u1 = t1 * t2 mod p */
    if (!BN_mod_mul(u1,t1,&t2,dsa->p,ctx))
        goto err;

    BN_copy(t1,u1);

    ret = 1;
err:
    BN_free(&t2);
    return(ret);
}

static DSA_SIG *
cryptodev_dsa_do_sign(const unsigned char *dgst, int dlen, DSA *dsa)
{
    struct crypt_kop kop;
    BIGNUM *r = NULL, *s = NULL;
    DSA_SIG *dsaret = NULL;

    if ((r = BN_new()) == NULL)
        goto err;
    if ((s = BN_new()) == NULL) {
        BN_free(r);
        goto err;
    }

    memset(&kop, 0, sizeof kop);
    kop.crk_op = CRK_DSA_SIGN;

    /* inputs: dgst dsa->p dsa->q dsa->g dsa->priv_key */
    kop.crk_param[0].crp_p = (caddr_t)dgst;
    kop.crk_param[0].crp_nbits = dlen * 8;
    if (bn2crparam(dsa->p, &kop.crk_param[1]))
        goto err;
    if (bn2crparam(dsa->q, &kop.crk_param[2]))
        goto err;
    if (bn2crparam(dsa->g, &kop.crk_param[3]))
        goto err;
    if (bn2crparam(dsa->priv_key, &kop.crk_param[4]))
        goto err;
    kop.crk_iparams = 5;

    if (cryptodev_asym(&kop, BN_num_bytes(dsa->q), r,
        BN_num_bytes(dsa->q), s) == 0) {
        dsaret = DSA_SIG_new();
        dsaret->r = r;
        dsaret->s = s;
    } else {
        const DSA_METHOD *meth = DSA_OpenSSL();
        BN_free(r);
        BN_free(s);
        dsaret = (meth->dsa_do_sign)(dgst, dlen, dsa);
    }
err:
    kop.crk_param[0].crp_p = NULL;
    zapparams(&kop);
    return (dsaret);
}

static int
cryptodev_dsa_verify(const unsigned char *dgst, int dlen,
    DSA_SIG *sig, DSA *dsa)
{
    struct crypt_kop kop;
    int dsaret = 1;

    memset(&kop, 0, sizeof kop);
    kop.crk_op = CRK_DSA_VERIFY;

    /* inputs: dgst dsa->p dsa->q dsa->g dsa->pub_key sig->r sig->s */
    kop.crk_param[0].crp_p = (caddr_t)dgst;
    kop.crk_param[0].crp_nbits = dlen * 8;
    if (bn2crparam(dsa->p, &kop.crk_param[1]))
        goto err;
    if (bn2crparam(dsa->q, &kop.crk_param[2]))
        goto err;
    if (bn2crparam(dsa->g, &kop.crk_param[3]))
        goto err;
    if (bn2crparam(dsa->pub_key, &kop.crk_param[4]))
        goto err;
    if (bn2crparam(sig->r, &kop.crk_param[5]))
        goto err;
    if (bn2crparam(sig->s, &kop.crk_param[6]))
        goto err;
    kop.crk_iparams = 7;

    if (cryptodev_asym(&kop, 0, NULL, 0, NULL) == 0) {
/*OCF success value is 0, if not zero, change dsaret to fail*/
        if(0 != kop.crk_status) dsaret  = 0;
    } else {
        const DSA_METHOD *meth = DSA_OpenSSL();

        dsaret = (meth->dsa_do_verify)(dgst, dlen, sig, dsa);
    }
err:
    kop.crk_param[0].crp_p = NULL;
    zapparams(&kop);
    return (dsaret);
}

static DSA_METHOD cryptodev_dsa = {
    "cryptodev DSA method",
    NULL,
    NULL,               /* dsa_sign_setup */
    NULL,
    NULL,               /* dsa_mod_exp */
    NULL,
    NULL,               /* init */
    NULL,               /* finish */
    0,  /* flags */
    NULL    /* app_data */
};

static int
cryptodev_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 (cryptodev_bn_mod_exp(r, a, p, m, ctx, m_ctx));
}

static int
cryptodev_dh_compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh)
{
    struct crypt_kop kop;
    int dhret = 1;
    int fd, keylen;

    if ((fd = get_asym_dev_crypto()) < 0) {
        const DH_METHOD *meth = DH_OpenSSL();

        return ((meth->compute_key)(key, pub_key, dh));
    }

    keylen = BN_num_bits(dh->p);

    memset(&kop, 0, sizeof kop);
    kop.crk_op = CRK_DH_COMPUTE_KEY;

    /* inputs: dh->priv_key pub_key dh->p key */
    if (bn2crparam(dh->priv_key, &kop.crk_param[0]))
        goto err;
    if (bn2crparam(pub_key, &kop.crk_param[1]))
        goto err;
    if (bn2crparam(dh->p, &kop.crk_param[2]))
        goto err;
    kop.crk_iparams = 3;

    kop.crk_param[3].crp_p = (caddr_t) key;
    kop.crk_param[3].crp_nbits = keylen * 8;
    kop.crk_oparams = 1;

    if (ioctl(fd, CIOCKEY, &kop) == -1) {
        const DH_METHOD *meth = DH_OpenSSL();

        dhret = (meth->compute_key)(key, pub_key, dh);
    }
err:
    kop.crk_param[3].crp_p = NULL;
    zapparams(&kop);
    return (dhret);
}

static DH_METHOD cryptodev_dh = {
    "cryptodev DH method",
    NULL,               /* cryptodev_dh_generate_key */
    NULL,
    NULL,
    NULL,
    NULL,
    0,  /* flags */
    NULL    /* app_data */
};

/*
 * ctrl right now is just a wrapper that doesn't do much
 * but I expect we'll want some options soon.
 */
static int
cryptodev_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f)(void))
{
#ifdef HAVE_SYSLOG_R
    struct syslog_data sd = SYSLOG_DATA_INIT;
#endif

    switch (cmd) {
    default:
#ifdef HAVE_SYSLOG_R
        syslog_r(LOG_ERR, &sd,
            "cryptodev_ctrl: unknown command %d", cmd);
#else
        syslog(LOG_ERR, "cryptodev_ctrl: unknown command %d", cmd);
#endif
        break;
    }
    return (1);
}

void
ENGINE_load_cryptodev(void)
{
    ENGINE *engine = ENGINE_new();
    int fd;

    if (engine == NULL)
        return;
    if ((fd = get_dev_crypto()) < 0) {
        ENGINE_free(engine);
        return;
    }

    /*
     * find out what asymmetric crypto algorithms we support
     */
    if (ioctl(fd, CIOCASYMFEAT, &cryptodev_asymfeat) == -1) {
        put_dev_crypto(fd);
        ENGINE_free(engine);
        return;
    }
    put_dev_crypto(fd);

    if (!ENGINE_set_id(engine, "cryptodev") ||
        !ENGINE_set_name(engine, "BSD cryptodev engine") ||
        !ENGINE_set_ciphers(engine, cryptodev_engine_ciphers) ||
        !ENGINE_set_digests(engine, cryptodev_engine_digests) ||
        !ENGINE_set_ctrl_function(engine, cryptodev_ctrl) ||
        !ENGINE_set_cmd_defns(engine, cryptodev_defns)) {
        ENGINE_free(engine);
        return;
    }

    if (ENGINE_set_RSA(engine, &cryptodev_rsa)) {
        const RSA_METHOD *rsa_meth = RSA_PKCS1_SSLeay();

        cryptodev_rsa.bn_mod_exp = rsa_meth->bn_mod_exp;
        cryptodev_rsa.rsa_mod_exp = rsa_meth->rsa_mod_exp;
        cryptodev_rsa.rsa_pub_enc = rsa_meth->rsa_pub_enc;
        cryptodev_rsa.rsa_pub_dec = rsa_meth->rsa_pub_dec;
        cryptodev_rsa.rsa_priv_enc = rsa_meth->rsa_priv_enc;
        cryptodev_rsa.rsa_priv_dec = rsa_meth->rsa_priv_dec;
        if (cryptodev_asymfeat & CRF_MOD_EXP) {
            cryptodev_rsa.bn_mod_exp = cryptodev_bn_mod_exp;
            if (cryptodev_asymfeat & CRF_MOD_EXP_CRT)
                cryptodev_rsa.rsa_mod_exp =
                    cryptodev_rsa_mod_exp;
            else
                cryptodev_rsa.rsa_mod_exp =
                    cryptodev_rsa_nocrt_mod_exp;
        }
    }

    if (ENGINE_set_DSA(engine, &cryptodev_dsa)) {
        const DSA_METHOD *meth = DSA_OpenSSL();

        memcpy(&cryptodev_dsa, meth, sizeof(DSA_METHOD));
        if (cryptodev_asymfeat & CRF_DSA_SIGN)
            cryptodev_dsa.dsa_do_sign = cryptodev_dsa_do_sign;
        if (cryptodev_asymfeat & CRF_MOD_EXP) {
            cryptodev_dsa.bn_mod_exp = cryptodev_dsa_bn_mod_exp;
            cryptodev_dsa.dsa_mod_exp = cryptodev_dsa_dsa_mod_exp;
        }
        if (cryptodev_asymfeat & CRF_DSA_VERIFY)
            cryptodev_dsa.dsa_do_verify = cryptodev_dsa_verify;
    }

    if (ENGINE_set_DH(engine, &cryptodev_dh)){
        const DH_METHOD *dh_meth = DH_OpenSSL();

        cryptodev_dh.generate_key = dh_meth->generate_key;
        cryptodev_dh.compute_key = dh_meth->compute_key;
        cryptodev_dh.bn_mod_exp = dh_meth->bn_mod_exp;
        if (cryptodev_asymfeat & CRF_MOD_EXP) {
            cryptodev_dh.bn_mod_exp = cryptodev_mod_exp_dh;
            if (cryptodev_asymfeat & CRF_DH_COMPUTE_KEY)
                cryptodev_dh.compute_key =
                    cryptodev_dh_compute_key;
        }
    }

    ENGINE_add(engine);
    ENGINE_free(engine);
    ERR_clear_error();
}

#endif /* HAVE_CRYPTODEV */