common/des/des_crypt.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 *
 */
/*
 * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*  Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
/*    All Rights Reserved   */

/*
 * Portions of this source code were derived from Berkeley 4.3 BSD
 * under license from the Regents of the University of California.
 */

/*
 * des_crypt.c, DES encryption library routines
 */

#include <sys/errno.h>
#include <sys/modctl.h>

#include <sys/systm.h>
#include <sys/cmn_err.h>
#include <sys/ddi.h>
#include <sys/crypto/common.h>
#include <sys/crypto/spi.h>
#include <sys/sysmacros.h>
#include <sys/strsun.h>
#include <sys/note.h>
#include <modes/modes.h>
#define _DES_IMPL
#include <des/des_impl.h>

#include <sys/types.h>
#include <rpc/des_crypt.h>
#include <des/des.h>

#ifdef sun_hardware
#include <sys/ioctl.h>
#ifdef _KERNEL
#include <sys/conf.h>
static int g_desfd = -1;
#define getdesfd()  (cdevsw[11].d_open(0, 0) ? -1 : 0)
#define ioctl(a, b, c)  (cdevsw[11].d_ioctl(0, b, c, 0) ? -1 : 0)
#else
#define getdesfd()  (open("/dev/des", 0, 0))
#endif  /* _KERNEL */
#endif  /* sun */

static int common_crypt(char *key, char *buf, size_t len,
    unsigned int mode, struct desparams *desp);

extern int _des_crypt(char *buf, size_t len, struct desparams *desp);

extern struct mod_ops mod_cryptoops;

/*
 * Module linkage information for the kernel.
 */
static struct modlmisc modlmisc = {
    &mod_miscops,
    "des encryption",
};

static struct modlcrypto modlcrypto = {
    &mod_cryptoops,
    "DES Kernel SW Provider"
};

static struct modlinkage modlinkage = {
    MODREV_1,
    &modlmisc,
    &modlcrypto,
    NULL
};

#define DES_MIN_KEY_LEN     DES_MINBYTES
#define DES_MAX_KEY_LEN     DES_MAXBYTES
#define DES3_MIN_KEY_LEN    DES3_MAXBYTES   /* no CKK_DES2 support */
#define DES3_MAX_KEY_LEN    DES3_MAXBYTES

#ifndef DES_MIN_KEY_LEN
#define DES_MIN_KEY_LEN     0
#endif

#ifndef DES_MAX_KEY_LEN
#define DES_MAX_KEY_LEN     0
#endif

#ifndef DES3_MIN_KEY_LEN
#define DES3_MIN_KEY_LEN    0
#endif

#ifndef DES3_MAX_KEY_LEN
#define DES3_MAX_KEY_LEN    0
#endif


/*
 * Mechanism info structure passed to KCF during registration.
 */
static crypto_mech_info_t des_mech_info_tab[] = {
    /* DES_ECB */
    {SUN_CKM_DES_ECB, DES_ECB_MECH_INFO_TYPE,
        CRYPTO_FG_ENCRYPT | CRYPTO_FG_ENCRYPT_ATOMIC |
        CRYPTO_FG_DECRYPT | CRYPTO_FG_DECRYPT_ATOMIC,
        DES_MIN_KEY_LEN, DES_MAX_KEY_LEN, CRYPTO_KEYSIZE_UNIT_IN_BYTES},
    /* DES_CBC */
    {SUN_CKM_DES_CBC, DES_CBC_MECH_INFO_TYPE,
        CRYPTO_FG_ENCRYPT | CRYPTO_FG_ENCRYPT_ATOMIC |
        CRYPTO_FG_DECRYPT | CRYPTO_FG_DECRYPT_ATOMIC,
        DES_MIN_KEY_LEN, DES_MAX_KEY_LEN, CRYPTO_KEYSIZE_UNIT_IN_BYTES},
    /* DES3_ECB */
    {SUN_CKM_DES3_ECB, DES3_ECB_MECH_INFO_TYPE,
        CRYPTO_FG_ENCRYPT | CRYPTO_FG_ENCRYPT_ATOMIC |
        CRYPTO_FG_DECRYPT | CRYPTO_FG_DECRYPT_ATOMIC,
        DES3_MIN_KEY_LEN, DES3_MAX_KEY_LEN, CRYPTO_KEYSIZE_UNIT_IN_BYTES},
    /* DES3_CBC */
    {SUN_CKM_DES3_CBC, DES3_CBC_MECH_INFO_TYPE,
        CRYPTO_FG_ENCRYPT | CRYPTO_FG_ENCRYPT_ATOMIC |
        CRYPTO_FG_DECRYPT | CRYPTO_FG_DECRYPT_ATOMIC,
        DES3_MIN_KEY_LEN, DES3_MAX_KEY_LEN, CRYPTO_KEYSIZE_UNIT_IN_BYTES}
};

/* operations are in-place if the output buffer is NULL */
#define DES_ARG_INPLACE(input, output)              \
    if ((output) == NULL)                   \
        (output) = (input);

static void des_provider_status(crypto_provider_handle_t, uint_t *);

static crypto_control_ops_t des_control_ops = {
    des_provider_status
};

static int
des_common_init(crypto_ctx_t *, crypto_mechanism_t *, crypto_key_t *,
    crypto_spi_ctx_template_t, crypto_req_handle_t);
static int des_common_init_ctx(des_ctx_t *, crypto_spi_ctx_template_t *,
    crypto_mechanism_t *, crypto_key_t *, des_strength_t, int);
static int des_encrypt_final(crypto_ctx_t *, crypto_data_t *,
    crypto_req_handle_t);
static int des_decrypt_final(crypto_ctx_t *, crypto_data_t *,
    crypto_req_handle_t);

static int des_encrypt(crypto_ctx_t *, crypto_data_t *, crypto_data_t *,
    crypto_req_handle_t);
static int des_encrypt_update(crypto_ctx_t *, crypto_data_t *,
    crypto_data_t *, crypto_req_handle_t);
static int des_encrypt_atomic(crypto_provider_handle_t, crypto_session_id_t,
    crypto_mechanism_t *, crypto_key_t *, crypto_data_t *,
    crypto_data_t *, crypto_spi_ctx_template_t, crypto_req_handle_t);

static int des_decrypt(crypto_ctx_t *, crypto_data_t *, crypto_data_t *,
    crypto_req_handle_t);
static int des_decrypt_update(crypto_ctx_t *, crypto_data_t *,
    crypto_data_t *, crypto_req_handle_t);
static int des_decrypt_atomic(crypto_provider_handle_t, crypto_session_id_t,
    crypto_mechanism_t *, crypto_key_t *, crypto_data_t *,
    crypto_data_t *, crypto_spi_ctx_template_t, crypto_req_handle_t);

static crypto_cipher_ops_t des_cipher_ops = {
    des_common_init,
    des_encrypt,
    des_encrypt_update,
    des_encrypt_final,
    des_encrypt_atomic,
    des_common_init,
    des_decrypt,
    des_decrypt_update,
    des_decrypt_final,
    des_decrypt_atomic
};

static int des_create_ctx_template(crypto_provider_handle_t,
    crypto_mechanism_t *, crypto_key_t *, crypto_spi_ctx_template_t *,
    size_t *, crypto_req_handle_t);
static int des_free_context(crypto_ctx_t *);

static crypto_ctx_ops_t des_ctx_ops = {
    des_create_ctx_template,
    des_free_context
};

static int des_key_check(crypto_provider_handle_t, crypto_mechanism_t *,
    crypto_key_t *);

static crypto_key_ops_t des_key_ops = {
    NULL,
    NULL,
    NULL,
    NULL,
    NULL,
    des_key_check
};

static crypto_ops_t des_crypto_ops = {
    &des_control_ops,
    NULL,
    &des_cipher_ops,
    NULL,
    NULL,
    NULL,
    NULL,
    NULL,
    NULL,
    NULL,
    NULL,
    &des_key_ops,
    NULL,
    &des_ctx_ops,
    NULL,
    NULL,
    NULL
};

static crypto_provider_info_t des_prov_info = {
    CRYPTO_SPI_VERSION_4,
    "DES Software Provider",
    CRYPTO_SW_PROVIDER,
    {&modlinkage},
    NULL,
    &des_crypto_ops,
    sizeof (des_mech_info_tab)/sizeof (crypto_mech_info_t),
    des_mech_info_tab
};

static crypto_kcf_provider_handle_t des_prov_handle = NULL;

int
_init(void)
{
    int ret;

    if ((ret = mod_install(&modlinkage)) != 0)
        return (ret);

    /*
     * Register with KCF. If the registration fails, kcf will log an
     * error but do not uninstall the module, since the functionality
     * provided by misc/des should still be available.
     *
     */
    (void) crypto_register_provider(&des_prov_info, &des_prov_handle);

    return (0);
}


int
_info(struct modinfo *modinfop)
{
    return (mod_info(&modlinkage, modinfop));
}

/*
 * Copy 8 bytes
 */
#define COPY8(src, dst) { \
    char *a = (char *)dst; \
    char *b = (char *)src; \
    *a++ = *b++; *a++ = *b++; *a++ = *b++; *a++ = *b++; \
    *a++ = *b++; *a++ = *b++; *a++ = *b++; *a++ = *b++; \
}

/*
 * Copy multiple of 8 bytes
 */
#define DESCOPY(src, dst, len) { \
    char *a = (char *)dst; \
    char *b = (char *)src; \
    int i; \
    for (i = (size_t)len; i > 0; i -= 8) { \
        *a++ = *b++; *a++ = *b++; *a++ = *b++; *a++ = *b++; \
        *a++ = *b++; *a++ = *b++; *a++ = *b++; *a++ = *b++; \
    } \
}

/*
 * CBC mode encryption
 */
/* ARGSUSED */
int
cbc_crypt(char *key, char *buf, size_t len, unsigned int mode, char *ivec)
{
    int err = 0;
    struct desparams dp;

    dp.des_mode = CBC;
    COPY8(ivec, dp.des_ivec);
    err = common_crypt(key, buf, len, mode, &dp);
    COPY8(dp.des_ivec, ivec);
    return (err);
}


/*
 * ECB mode encryption
 */
/* ARGSUSED */
int
ecb_crypt(char *key, char *buf, size_t len, unsigned int mode)
{
    int err = 0;
    struct desparams dp;

    dp.des_mode = ECB;
    err = common_crypt(key, buf, len, mode, &dp);
    return (err);
}


/*
 * Common code to cbc_crypt() & ecb_crypt()
 */
static int
common_crypt(char *key, char *buf, size_t len, unsigned int mode,
    struct desparams *desp)
{
    int desdev;

    if ((len % 8) != 0 || len > DES_MAXDATA)
        return (DESERR_BADPARAM);

    desp->des_dir =
        ((mode & DES_DIRMASK) == DES_ENCRYPT) ? ENCRYPT : DECRYPT;

    desdev = mode & DES_DEVMASK;
    COPY8(key, desp->des_key);

#ifdef sun_hardware
    if (desdev == DES_HW) {
        int res;

        if (g_desfd < 0 &&
            (g_desfd == -1 || (g_desfd = getdesfd()) < 0))
                goto software;  /* no hardware device */

        /*
         * hardware
         */
        desp->des_len = len;
        if (len <= DES_QUICKLEN) {
            DESCOPY(buf, desp->des_data, len);
            res = ioctl(g_desfd, DESIOCQUICK, (char *)desp);
            DESCOPY(desp->des_data, buf, len);
        } else {
            desp->des_buf = (uchar_t *)buf;
            res = ioctl(g_desfd, DESIOCBLOCK, (char *)desp);
        }
        return (res == 0 ? DESERR_NONE : DESERR_HWERROR);
    }
software:
#endif
    /*
     * software
     */
    if (!_des_crypt(buf, len, desp))
        return (DESERR_HWERROR);

    return (desdev == DES_SW ? DESERR_NONE : DESERR_NOHWDEVICE);
}

/*
 * Initialize key schedules for DES and DES3
 */
static int
init_keysched(crypto_key_t *key, void *newbie, des_strength_t strength)
{
    uint8_t corrected_key[DES3_KEYSIZE];

    /*
     * Only keys by value are supported by this module.
     */
    switch (key->ck_format) {
    case CRYPTO_KEY_RAW:
        if (strength == DES && key->ck_length != DES_MAXBITS)
            return (CRYPTO_KEY_SIZE_RANGE);
        if (strength == DES3 && key->ck_length != DES3_MAXBITS)
            return (CRYPTO_KEY_SIZE_RANGE);
        break;
    default:
        return (CRYPTO_KEY_TYPE_INCONSISTENT);
    }

    /*
     * Fix parity bits.
     * Initialize key schedule even if key is weak.
     */
    if (key->ck_data == NULL)
        return (CRYPTO_ARGUMENTS_BAD);

    des_parity_fix(key->ck_data, strength, corrected_key);
    des_init_keysched(corrected_key, strength, newbie);
    return (CRYPTO_SUCCESS);
}

/*
 * KCF software provider control entry points.
 */
/* ARGSUSED */
static void
des_provider_status(crypto_provider_handle_t provider, uint_t *status)
{
    *status = CRYPTO_PROVIDER_READY;
}

/*
 * KCF software provider encrypt entry points.
 */
static int
des_common_init(crypto_ctx_t *ctx, crypto_mechanism_t *mechanism,
    crypto_key_t *key, crypto_spi_ctx_template_t template,
    crypto_req_handle_t req)
{

    des_strength_t strength;
    des_ctx_t *des_ctx = NULL;
    int rv;
    int kmflag;

    /*
     * Only keys by value are supported by this module.
     */
    if (key->ck_format != CRYPTO_KEY_RAW) {
        return (CRYPTO_KEY_TYPE_INCONSISTENT);
    }

    kmflag = crypto_kmflag(req);
    /* Check mechanism type and parameter length */
    switch (mechanism->cm_type) {
    case DES_ECB_MECH_INFO_TYPE:
        des_ctx = ecb_alloc_ctx(kmflag);
        /* FALLTHRU */
    case DES_CBC_MECH_INFO_TYPE:
        if (mechanism->cm_param != NULL &&
            mechanism->cm_param_len != DES_BLOCK_LEN)
            return (CRYPTO_MECHANISM_PARAM_INVALID);
        if (key->ck_length != DES_MAXBITS)
            return (CRYPTO_KEY_SIZE_RANGE);
        strength = DES;
        if (des_ctx == NULL)
            des_ctx = cbc_alloc_ctx(kmflag);
        break;
    case DES3_ECB_MECH_INFO_TYPE:
        des_ctx = ecb_alloc_ctx(kmflag);
        /* FALLTHRU */
    case DES3_CBC_MECH_INFO_TYPE:
        if (mechanism->cm_param != NULL &&
            mechanism->cm_param_len != DES_BLOCK_LEN)
            return (CRYPTO_MECHANISM_PARAM_INVALID);
        if (key->ck_length != DES3_MAXBITS)
            return (CRYPTO_KEY_SIZE_RANGE);
        strength = DES3;
        if (des_ctx == NULL)
            des_ctx = cbc_alloc_ctx(kmflag);
        break;
    default:
        return (CRYPTO_MECHANISM_INVALID);
    }

    if ((rv = des_common_init_ctx(des_ctx, template, mechanism, key,
        strength, kmflag)) != CRYPTO_SUCCESS) {
        crypto_free_mode_ctx(des_ctx);
        return (rv);
    }

    ctx->cc_provider_private = des_ctx;

    return (CRYPTO_SUCCESS);
}

static void
des_copy_block64(uint8_t *in, uint64_t *out)
{
    if (IS_P2ALIGNED(in, sizeof (uint64_t))) {
        /* LINTED: pointer alignment */
        out[0] = *(uint64_t *)&in[0];
    } else {
        uint64_t tmp64;

#ifdef _BIG_ENDIAN
        tmp64 = (((uint64_t)in[0] << 56) |
            ((uint64_t)in[1] << 48) |
            ((uint64_t)in[2] << 40) |
            ((uint64_t)in[3] << 32) |
            ((uint64_t)in[4] << 24) |
            ((uint64_t)in[5] << 16) |
            ((uint64_t)in[6] << 8) |
            (uint64_t)in[7]);
#else
        tmp64 = (((uint64_t)in[7] << 56) |
            ((uint64_t)in[6] << 48) |
            ((uint64_t)in[5] << 40) |
            ((uint64_t)in[4] << 32) |
            ((uint64_t)in[3] << 24) |
            ((uint64_t)in[2] << 16) |
            ((uint64_t)in[1] << 8) |
            (uint64_t)in[0]);
#endif /* _BIG_ENDIAN */

        out[0] = tmp64;
    }
}

/* ARGSUSED */
static int
des_encrypt(crypto_ctx_t *ctx, crypto_data_t *plaintext,
    crypto_data_t *ciphertext, crypto_req_handle_t req)
{
    int ret;

    des_ctx_t *des_ctx;

    /*
     * Plaintext must be a multiple of the block size.
     * This test only works for non-padded mechanisms
     * when blocksize is 2^N.
     */
    if ((plaintext->cd_length & (DES_BLOCK_LEN - 1)) != 0)
        return (CRYPTO_DATA_LEN_RANGE);

    ASSERT(ctx->cc_provider_private != NULL);
    des_ctx = ctx->cc_provider_private;

    DES_ARG_INPLACE(plaintext, ciphertext);

    /*
     * We need to just return the length needed to store the output.
     * We should not destroy the context for the following case.
     */
    if (ciphertext->cd_length < plaintext->cd_length) {
        ciphertext->cd_length = plaintext->cd_length;
        return (CRYPTO_BUFFER_TOO_SMALL);
    }

    /*
     * Do an update on the specified input data.
     */
    ret = des_encrypt_update(ctx, plaintext, ciphertext, req);
    ASSERT(des_ctx->dc_remainder_len == 0);
    (void) des_free_context(ctx);

    /* LINTED */
    return (ret);
}

/* ARGSUSED */
static int
des_decrypt(crypto_ctx_t *ctx, crypto_data_t *ciphertext,
    crypto_data_t *plaintext, crypto_req_handle_t req)
{
    int ret;

    des_ctx_t *des_ctx;

    /*
     * Ciphertext must be a multiple of the block size.
     * This test only works for non-padded mechanisms
     * when blocksize is 2^N.
     */
    if ((ciphertext->cd_length & (DES_BLOCK_LEN - 1)) != 0)
        return (CRYPTO_ENCRYPTED_DATA_LEN_RANGE);

    ASSERT(ctx->cc_provider_private != NULL);
    des_ctx = ctx->cc_provider_private;

    DES_ARG_INPLACE(ciphertext, plaintext);

    /*
     * We need to just return the length needed to store the output.
     * We should not destroy the context for the following case.
     */
    if (plaintext->cd_length < ciphertext->cd_length) {
        plaintext->cd_length = ciphertext->cd_length;
        return (CRYPTO_BUFFER_TOO_SMALL);
    }

    /*
     * Do an update on the specified input data.
     */
    ret = des_decrypt_update(ctx, ciphertext, plaintext, req);
    ASSERT(des_ctx->dc_remainder_len == 0);
    (void) des_free_context(ctx);

    /* LINTED */
    return (ret);
}

/* ARGSUSED */
static int
des_encrypt_update(crypto_ctx_t *ctx, crypto_data_t *plaintext,
    crypto_data_t *ciphertext, crypto_req_handle_t req)
{
    off_t saved_offset;
    size_t saved_length, out_len;
    int ret = CRYPTO_SUCCESS;

    ASSERT(ctx->cc_provider_private != NULL);

    DES_ARG_INPLACE(plaintext, ciphertext);

    /* compute number of bytes that will hold the ciphertext */
    out_len = ((des_ctx_t *)ctx->cc_provider_private)->dc_remainder_len;
    out_len += plaintext->cd_length;
    out_len &= ~(DES_BLOCK_LEN - 1);

    /* return length needed to store the output */
    if (ciphertext->cd_length < out_len) {
        ciphertext->cd_length = out_len;
        return (CRYPTO_BUFFER_TOO_SMALL);
    }

    saved_offset = ciphertext->cd_offset;
    saved_length = ciphertext->cd_length;

    /*
     * Do the DES update on the specified input data.
     */
    switch (plaintext->cd_format) {
    case CRYPTO_DATA_RAW:
        ret = crypto_update_iov(ctx->cc_provider_private,
            plaintext, ciphertext, des_encrypt_contiguous_blocks,
            des_copy_block64);
        break;
    case CRYPTO_DATA_UIO:
        ret = crypto_update_uio(ctx->cc_provider_private,
            plaintext, ciphertext, des_encrypt_contiguous_blocks,
            des_copy_block64);
        break;
    case CRYPTO_DATA_MBLK:
        ret = crypto_update_mp(ctx->cc_provider_private,
            plaintext, ciphertext, des_encrypt_contiguous_blocks,
            des_copy_block64);
        break;
    default:
        ret = CRYPTO_ARGUMENTS_BAD;
    }

    if (ret == CRYPTO_SUCCESS) {
        if (plaintext != ciphertext)
            ciphertext->cd_length =
                ciphertext->cd_offset - saved_offset;
    } else {
        ciphertext->cd_length = saved_length;
    }
    ciphertext->cd_offset = saved_offset;

    return (ret);
}

/* ARGSUSED */
static int
des_decrypt_update(crypto_ctx_t *ctx, crypto_data_t *ciphertext,
    crypto_data_t *plaintext, crypto_req_handle_t req)
{
    off_t saved_offset;
    size_t saved_length, out_len;
    int ret = CRYPTO_SUCCESS;

    ASSERT(ctx->cc_provider_private != NULL);

    DES_ARG_INPLACE(ciphertext, plaintext);

    /* compute number of bytes that will hold the plaintext */
    out_len = ((des_ctx_t *)ctx->cc_provider_private)->dc_remainder_len;
    out_len += ciphertext->cd_length;
    out_len &= ~(DES_BLOCK_LEN - 1);

    /* return length needed to store the output */
    if (plaintext->cd_length < out_len) {
        plaintext->cd_length = out_len;
        return (CRYPTO_BUFFER_TOO_SMALL);
    }

    saved_offset = plaintext->cd_offset;
    saved_length = plaintext->cd_length;

    /*
     * Do the DES update on the specified input data.
     */
    switch (ciphertext->cd_format) {
    case CRYPTO_DATA_RAW:
        ret = crypto_update_iov(ctx->cc_provider_private,
            ciphertext, plaintext, des_decrypt_contiguous_blocks,
            des_copy_block64);
        break;
    case CRYPTO_DATA_UIO:
        ret = crypto_update_uio(ctx->cc_provider_private,
            ciphertext, plaintext, des_decrypt_contiguous_blocks,
            des_copy_block64);
        break;
    case CRYPTO_DATA_MBLK:
        ret = crypto_update_mp(ctx->cc_provider_private,
            ciphertext, plaintext, des_decrypt_contiguous_blocks,
            des_copy_block64);
        break;
    default:
        ret = CRYPTO_ARGUMENTS_BAD;
    }

    if (ret == CRYPTO_SUCCESS) {
        if (ciphertext != plaintext)
            plaintext->cd_length =
                plaintext->cd_offset - saved_offset;
    } else {
        plaintext->cd_length = saved_length;
    }
    plaintext->cd_offset = saved_offset;

    return (ret);
}

/* ARGSUSED */
static int
des_encrypt_final(crypto_ctx_t *ctx, crypto_data_t *ciphertext,
    crypto_req_handle_t req)
{
    des_ctx_t *des_ctx;

    ASSERT(ctx->cc_provider_private != NULL);
    des_ctx = ctx->cc_provider_private;

    /*
     * There must be no unprocessed plaintext.
     * This happens if the length of the last data is
     * not a multiple of the DES block length.
     */
    if (des_ctx->dc_remainder_len > 0)
        return (CRYPTO_DATA_LEN_RANGE);

    (void) des_free_context(ctx);
    ciphertext->cd_length = 0;

    return (CRYPTO_SUCCESS);
}

/* ARGSUSED */
static int
des_decrypt_final(crypto_ctx_t *ctx, crypto_data_t *plaintext,
    crypto_req_handle_t req)
{
    des_ctx_t *des_ctx;

    ASSERT(ctx->cc_provider_private != NULL);
    des_ctx = ctx->cc_provider_private;

    /*
     * There must be no unprocessed ciphertext.
     * This happens if the length of the last ciphertext is
     * not a multiple of the DES block length.
     */
    if (des_ctx->dc_remainder_len > 0)
        return (CRYPTO_ENCRYPTED_DATA_LEN_RANGE);

    (void) des_free_context(ctx);
    plaintext->cd_length = 0;

    return (CRYPTO_SUCCESS);
}

/* ARGSUSED */
static int
des_encrypt_atomic(crypto_provider_handle_t provider,
    crypto_session_id_t session_id, crypto_mechanism_t *mechanism,
    crypto_key_t *key, crypto_data_t *plaintext, crypto_data_t *ciphertext,
    crypto_spi_ctx_template_t template, crypto_req_handle_t req)
{
    int ret;

    des_ctx_t des_ctx;      /* on the stack */
    des_strength_t strength;
    off_t saved_offset;
    size_t saved_length;

    DES_ARG_INPLACE(plaintext, ciphertext);

    /*
     * Plaintext must be a multiple of the block size.
     * This test only works for non-padded mechanisms
     * when blocksize is 2^N.
     */
    if ((plaintext->cd_length & (DES_BLOCK_LEN - 1)) != 0)
        return (CRYPTO_DATA_LEN_RANGE);

    /* return length needed to store the output */
    if (ciphertext->cd_length < plaintext->cd_length) {
        ciphertext->cd_length = plaintext->cd_length;
        return (CRYPTO_BUFFER_TOO_SMALL);
    }

    /* Check mechanism type and parameter length */
    switch (mechanism->cm_type) {
    case DES_ECB_MECH_INFO_TYPE:
    case DES_CBC_MECH_INFO_TYPE:
        if (mechanism->cm_param_len > 0 &&
            mechanism->cm_param_len != DES_BLOCK_LEN)
            return (CRYPTO_MECHANISM_PARAM_INVALID);
        if (key->ck_length != DES_MINBITS)
            return (CRYPTO_KEY_SIZE_RANGE);
        strength = DES;
        break;
    case DES3_ECB_MECH_INFO_TYPE:
    case DES3_CBC_MECH_INFO_TYPE:
        if (mechanism->cm_param_len > 0 &&
            mechanism->cm_param_len != DES_BLOCK_LEN)
            return (CRYPTO_MECHANISM_PARAM_INVALID);
        if (key->ck_length != DES3_MAXBITS)
            return (CRYPTO_KEY_SIZE_RANGE);
        strength = DES3;
        break;
    default:
        return (CRYPTO_MECHANISM_INVALID);
    }

    bzero(&des_ctx, sizeof (des_ctx_t));

    if ((ret = des_common_init_ctx(&des_ctx, template, mechanism, key,
        strength, crypto_kmflag(req))) != CRYPTO_SUCCESS) {
        return (ret);
    }

    saved_offset = ciphertext->cd_offset;
    saved_length = ciphertext->cd_length;

    /*
     * Do the update on the specified input data.
     */
    switch (plaintext->cd_format) {
    case CRYPTO_DATA_RAW:
        ret = crypto_update_iov(&des_ctx, plaintext, ciphertext,
            des_encrypt_contiguous_blocks, des_copy_block64);
        break;
    case CRYPTO_DATA_UIO:
        ret = crypto_update_uio(&des_ctx, plaintext, ciphertext,
            des_encrypt_contiguous_blocks, des_copy_block64);
        break;
    case CRYPTO_DATA_MBLK:
        ret = crypto_update_mp(&des_ctx, plaintext, ciphertext,
            des_encrypt_contiguous_blocks, des_copy_block64);
        break;
    default:
        ret = CRYPTO_ARGUMENTS_BAD;
    }

    if (des_ctx.dc_flags & PROVIDER_OWNS_KEY_SCHEDULE) {
        bzero(des_ctx.dc_keysched, des_ctx.dc_keysched_len);
        kmem_free(des_ctx.dc_keysched, des_ctx.dc_keysched_len);
    }

    if (ret == CRYPTO_SUCCESS) {
        ASSERT(des_ctx.dc_remainder_len == 0);
        if (plaintext != ciphertext)
            ciphertext->cd_length =
                ciphertext->cd_offset - saved_offset;
    } else {
        ciphertext->cd_length = saved_length;
    }
    ciphertext->cd_offset = saved_offset;

    /* LINTED */
    return (ret);
}

/* ARGSUSED */
static int
des_decrypt_atomic(crypto_provider_handle_t provider,
    crypto_session_id_t session_id, crypto_mechanism_t *mechanism,
    crypto_key_t *key, crypto_data_t *ciphertext, crypto_data_t *plaintext,
    crypto_spi_ctx_template_t template, crypto_req_handle_t req)
{
    int ret;

    des_ctx_t des_ctx;  /* on the stack */
    des_strength_t strength;
    off_t saved_offset;
    size_t saved_length;

    DES_ARG_INPLACE(ciphertext, plaintext);

    /*
     * Ciphertext must be a multiple of the block size.
     * This test only works for non-padded mechanisms
     * when blocksize is 2^N.
     */
    if ((ciphertext->cd_length & (DES_BLOCK_LEN - 1)) != 0)
        return (CRYPTO_DATA_LEN_RANGE);

    /* return length needed to store the output */
    if (plaintext->cd_length < ciphertext->cd_length) {
        plaintext->cd_length = ciphertext->cd_length;
        return (CRYPTO_BUFFER_TOO_SMALL);
    }

    /* Check mechanism type and parameter length */
    switch (mechanism->cm_type) {
    case DES_ECB_MECH_INFO_TYPE:
    case DES_CBC_MECH_INFO_TYPE:
        if (mechanism->cm_param_len > 0 &&
            mechanism->cm_param_len != DES_BLOCK_LEN)
            return (CRYPTO_MECHANISM_PARAM_INVALID);
        if (key->ck_length != DES_MINBITS)
            return (CRYPTO_KEY_SIZE_RANGE);
        strength = DES;
        break;
    case DES3_ECB_MECH_INFO_TYPE:
    case DES3_CBC_MECH_INFO_TYPE:
        if (mechanism->cm_param_len > 0 &&
            mechanism->cm_param_len != DES_BLOCK_LEN)
            return (CRYPTO_MECHANISM_PARAM_INVALID);
        if (key->ck_length != DES3_MAXBITS)
            return (CRYPTO_KEY_SIZE_RANGE);
        strength = DES3;
        break;
    default:
        return (CRYPTO_MECHANISM_INVALID);
    }

    bzero(&des_ctx, sizeof (des_ctx_t));

    if ((ret = des_common_init_ctx(&des_ctx, template, mechanism, key,
        strength, crypto_kmflag(req))) != CRYPTO_SUCCESS) {
        return (ret);
    }

    saved_offset = plaintext->cd_offset;
    saved_length = plaintext->cd_length;

    /*
     * Do the update on the specified input data.
     */
    switch (ciphertext->cd_format) {
    case CRYPTO_DATA_RAW:
        ret = crypto_update_iov(&des_ctx, ciphertext, plaintext,
            des_decrypt_contiguous_blocks, des_copy_block64);
        break;
    case CRYPTO_DATA_UIO:
        ret = crypto_update_uio(&des_ctx, ciphertext, plaintext,
            des_decrypt_contiguous_blocks, des_copy_block64);
        break;
    case CRYPTO_DATA_MBLK:
        ret = crypto_update_mp(&des_ctx, ciphertext, plaintext,
            des_decrypt_contiguous_blocks, des_copy_block64);
        break;
    default:
        ret = CRYPTO_ARGUMENTS_BAD;
    }

    if (des_ctx.dc_flags & PROVIDER_OWNS_KEY_SCHEDULE) {
        bzero(des_ctx.dc_keysched, des_ctx.dc_keysched_len);
        kmem_free(des_ctx.dc_keysched, des_ctx.dc_keysched_len);
    }

    if (ret == CRYPTO_SUCCESS) {
        ASSERT(des_ctx.dc_remainder_len == 0);
        if (ciphertext != plaintext)
            plaintext->cd_length =
                plaintext->cd_offset - saved_offset;
    } else {
        plaintext->cd_length = saved_length;
    }
    plaintext->cd_offset = saved_offset;

    /* LINTED */
    return (ret);
}

/*
 * KCF software provider context template entry points.
 */
/* ARGSUSED */
static int
des_create_ctx_template(crypto_provider_handle_t provider,
    crypto_mechanism_t *mechanism, crypto_key_t *key,
    crypto_spi_ctx_template_t *tmpl, size_t *tmpl_size, crypto_req_handle_t req)
{

    des_strength_t strength;
    void *keysched;
    size_t size;
    int rv;

    switch (mechanism->cm_type) {
    case DES_ECB_MECH_INFO_TYPE:
        strength = DES;
        break;
    case DES_CBC_MECH_INFO_TYPE:
        strength = DES;
        break;
    case DES3_ECB_MECH_INFO_TYPE:
        strength = DES3;
        break;
    case DES3_CBC_MECH_INFO_TYPE:
        strength = DES3;
        break;
    default:
        return (CRYPTO_MECHANISM_INVALID);
    }

    if ((keysched = des_alloc_keysched(&size, strength,
        crypto_kmflag(req))) == NULL) {
        return (CRYPTO_HOST_MEMORY);
    }

    /*
     * Initialize key schedule.  Key length information is stored
     * in the key.
     */
    if ((rv = init_keysched(key, keysched, strength)) != CRYPTO_SUCCESS) {
        bzero(keysched, size);
        kmem_free(keysched, size);
        return (rv);
    }

    *tmpl = keysched;
    *tmpl_size = size;

    return (CRYPTO_SUCCESS);
}

/* ARGSUSED */
static int
des_free_context(crypto_ctx_t *ctx)
{
    des_ctx_t *des_ctx = ctx->cc_provider_private;

    if (des_ctx != NULL) {
        if (des_ctx->dc_flags & PROVIDER_OWNS_KEY_SCHEDULE) {
            ASSERT(des_ctx->dc_keysched_len != 0);
            bzero(des_ctx->dc_keysched, des_ctx->dc_keysched_len);
            kmem_free(des_ctx->dc_keysched,
                des_ctx->dc_keysched_len);
        }
        crypto_free_mode_ctx(des_ctx);
        ctx->cc_provider_private = NULL;
    }

    return (CRYPTO_SUCCESS);
}

/*
 * Pass it to des_keycheck() which will
 * fix it (parity bits), and check if the fixed key is weak.
 */
/* ARGSUSED */
static int
des_key_check(crypto_provider_handle_t pd, crypto_mechanism_t *mech,
    crypto_key_t *key)
{
    int expectedkeylen;
    des_strength_t strength;
    uint8_t keydata[DES3_MAX_KEY_LEN];

    if ((mech == NULL) || (key == NULL))
        return (CRYPTO_ARGUMENTS_BAD);

    switch (mech->cm_type) {
    case DES_ECB_MECH_INFO_TYPE:
    case DES_CBC_MECH_INFO_TYPE:
        expectedkeylen = DES_MINBITS;
        strength = DES;
        break;
    case DES3_ECB_MECH_INFO_TYPE:
    case DES3_CBC_MECH_INFO_TYPE:
        expectedkeylen = DES3_MAXBITS;
        strength = DES3;
        break;
    default:
        return (CRYPTO_MECHANISM_INVALID);
    }

    if (key->ck_format != CRYPTO_KEY_RAW)
        return (CRYPTO_KEY_TYPE_INCONSISTENT);

    if (key->ck_length != expectedkeylen)
        return (CRYPTO_KEY_SIZE_RANGE);

    bcopy(key->ck_data, keydata, CRYPTO_BITS2BYTES(expectedkeylen));

    if (des_keycheck(keydata, strength, key->ck_data) == B_FALSE)
        return (CRYPTO_WEAK_KEY);

    return (CRYPTO_SUCCESS);
}

/* ARGSUSED */
static int
des_common_init_ctx(des_ctx_t *des_ctx, crypto_spi_ctx_template_t *template,
    crypto_mechanism_t *mechanism, crypto_key_t *key, des_strength_t strength,
    int kmflag)
{
    int rv = CRYPTO_SUCCESS;

    void *keysched;
    size_t size;

    if (template == NULL) {
        if ((keysched = des_alloc_keysched(&size, strength,
            kmflag)) == NULL)
            return (CRYPTO_HOST_MEMORY);
        /*
         * Initialize key schedule.
         * Key length is stored in the key.
         */
        if ((rv = init_keysched(key, keysched,
            strength)) != CRYPTO_SUCCESS)
            kmem_free(keysched, size);

        des_ctx->dc_flags |= PROVIDER_OWNS_KEY_SCHEDULE;
        des_ctx->dc_keysched_len = size;
    } else {
        keysched = template;
    }
    des_ctx->dc_keysched = keysched;

    if (strength == DES3) {
        des_ctx->dc_flags |= DES3_STRENGTH;
    }

    switch (mechanism->cm_type) {
    case DES_CBC_MECH_INFO_TYPE:
    case DES3_CBC_MECH_INFO_TYPE:
        rv = cbc_init_ctx((cbc_ctx_t *)des_ctx, mechanism->cm_param,
            mechanism->cm_param_len, DES_BLOCK_LEN, des_copy_block64);
        break;
    case DES_ECB_MECH_INFO_TYPE:
    case DES3_ECB_MECH_INFO_TYPE:
        des_ctx->dc_flags |= ECB_MODE;
    }

    if (rv != CRYPTO_SUCCESS) {
        if (des_ctx->dc_flags & PROVIDER_OWNS_KEY_SCHEDULE) {
            bzero(keysched, size);
            kmem_free(keysched, size);
        }
    }

    return (rv);
}