/*
 * 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.
 */

/*
 * In kernel module, the md4 module is created with one modlinkage,
 * this is different to md5 and sha1 modules which have a legacy misc
 * variant for direct calls to the Init/Update/Final routines.
 *
 * - a modlcrypto that allows the module to register with the Kernel
 *   Cryptographic Framework (KCF) as a software provider for the MD4
 *   mechanisms.
 */

#include <sys/types.h>
#include <sys/systm.h>
#include <sys/modctl.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 <sys/md4.h>

extern struct mod_ops mod_miscops;
extern struct mod_ops mod_cryptoops;

/*
 * Module linkage information for the kernel.
 */

static struct modlcrypto modlcrypto = {
        &mod_cryptoops,
        "MD4 Kernel SW Provider"
};

static struct modlinkage modlinkage = {
        MODREV_1,
        (void *)&modlcrypto,
        NULL
};

/*
 * CSPI information (entry points, provider info, etc.)
 */

typedef enum md4_mech_type {
        MD4_MECH_INFO_TYPE,             /* SUN_CKM_MD4 */
} md4_mech_type_t;

#define MD4_DIGEST_LENGTH       16      /* MD4 digest length in bytes */

/*
 * Context for MD4 mechanism.
 */
typedef struct md4_ctx {
        md4_mech_type_t         mc_mech_type;   /* type of context */
        MD4_CTX                 mc_md4_ctx;     /* MD4 context */
} md4_ctx_t;

/*
 * Macros to access the MD4 contexts from a context passed
 * by KCF to one of the entry points.
 */

#define PROV_MD4_CTX(ctx)       ((md4_ctx_t *)(ctx)->cc_provider_private)

/*
 * Mechanism info structure passed to KCF during registration.
 */
static crypto_mech_info_t md4_mech_info_tab[] = {
        /* MD4 */
        {SUN_CKM_MD4, MD4_MECH_INFO_TYPE,
            CRYPTO_FG_DIGEST | CRYPTO_FG_DIGEST_ATOMIC,
            0, 0, CRYPTO_KEYSIZE_UNIT_IN_BITS},
};

static void md4_provider_status(crypto_provider_handle_t, uint_t *);

static crypto_control_ops_t md4_control_ops = {
        md4_provider_status
};

static int md4_digest_init(crypto_ctx_t *, crypto_mechanism_t *,
    crypto_req_handle_t);
static int md4_digest(crypto_ctx_t *, crypto_data_t *, crypto_data_t *,
    crypto_req_handle_t);
static int md4_digest_update(crypto_ctx_t *, crypto_data_t *,
    crypto_req_handle_t);
static int md4_digest_final(crypto_ctx_t *, crypto_data_t *,
    crypto_req_handle_t);
static int md4_digest_atomic(crypto_provider_handle_t, crypto_session_id_t,
    crypto_mechanism_t *, crypto_data_t *, crypto_data_t *,
    crypto_req_handle_t);

static crypto_digest_ops_t md4_digest_ops = {
        md4_digest_init,
        md4_digest,
        md4_digest_update,
        NULL,
        md4_digest_final,
        md4_digest_atomic
};

static crypto_ops_t md4_crypto_ops = {
        &md4_control_ops,
        &md4_digest_ops,
        NULL,
        NULL,
        NULL,
        NULL,
        NULL,
        NULL,
        NULL,
        NULL,
        NULL,
        NULL,
        NULL,
        NULL,
};

static crypto_provider_info_t md4_prov_info = {
        CRYPTO_SPI_VERSION_1,
        "MD4 Software Provider",
        CRYPTO_SW_PROVIDER,
        {&modlinkage},
        NULL,
        &md4_crypto_ops,
        sizeof (md4_mech_info_tab)/sizeof (crypto_mech_info_t),
        md4_mech_info_tab
};

static crypto_kcf_provider_handle_t md4_prov_handle = 0;

int
_init(void)
{
        int ret;

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

        /* Register with KCF.  If the registration fails, remove the module. */
        if (crypto_register_provider(&md4_prov_info, &md4_prov_handle)) {
                (void) mod_remove(&modlinkage);
                return (EACCES);
        }

        return (0);
}

int
_fini(void)
{
        /* Unregister from KCF if module is registered */
        if (md4_prov_handle != 0) {
                if (crypto_unregister_provider(md4_prov_handle))
                        return (EBUSY);

                md4_prov_handle = 0;
        }

        return (mod_remove(&modlinkage));
}

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

/*
 * KCF software provider control entry points.
 */
/* ARGSUSED */
static void
md4_provider_status(crypto_provider_handle_t provider, uint_t *status)
{
        *status = CRYPTO_PROVIDER_READY;
}

/*
 * KCF software provider digest entry points.
 */

static int
md4_digest_init(crypto_ctx_t *ctx, crypto_mechanism_t *mechanism,
    crypto_req_handle_t req)
{
        if (mechanism->cm_type != MD4_MECH_INFO_TYPE)
                return (CRYPTO_MECHANISM_INVALID);

        /*
         * Allocate and initialize MD4 context.
         */
        ctx->cc_provider_private = kmem_alloc(sizeof (md4_ctx_t),
            crypto_kmflag(req));
        if (ctx->cc_provider_private == NULL)
                return (CRYPTO_HOST_MEMORY);

        PROV_MD4_CTX(ctx)->mc_mech_type = MD4_MECH_INFO_TYPE;
        MD4Init(&PROV_MD4_CTX(ctx)->mc_md4_ctx);

        return (CRYPTO_SUCCESS);
}

/*
 * Helper MD4 digest update function for uio data.
 */
static int
md4_digest_update_uio(MD4_CTX *md4_ctx, crypto_data_t *data)
{
        off_t offset = data->cd_offset;
        size_t length = data->cd_length;
        uint_t vec_idx;
        size_t cur_len;

        /* we support only kernel buffer */
        if (data->cd_uio->uio_segflg != UIO_SYSSPACE)
                return (CRYPTO_ARGUMENTS_BAD);

        /*
         * Jump to the first iovec containing data to be
         * digested.
         */
        for (vec_idx = 0; vec_idx < data->cd_uio->uio_iovcnt &&
            offset >= data->cd_uio->uio_iov[vec_idx].iov_len;
            offset -= data->cd_uio->uio_iov[vec_idx++].iov_len)
                ;
        if (vec_idx == data->cd_uio->uio_iovcnt) {
                /*
                 * The caller specified an offset that is larger than the
                 * total size of the buffers it provided.
                 */
                return (CRYPTO_DATA_LEN_RANGE);
        }

        /*
         * Now do the digesting on the iovecs.
         */
        while (vec_idx < data->cd_uio->uio_iovcnt && length > 0) {
                cur_len = MIN(data->cd_uio->uio_iov[vec_idx].iov_len -
                    offset, length);

                MD4Update(md4_ctx, data->cd_uio->uio_iov[vec_idx].iov_base +
                    offset, cur_len);

                length -= cur_len;
                vec_idx++;
                offset = 0;
        }

        if (vec_idx == data->cd_uio->uio_iovcnt && length > 0) {
                /*
                 * The end of the specified iovec's was reached but
                 * the length requested could not be processed, i.e.
                 * The caller requested to digest more data than it provided.
                 */
                return (CRYPTO_DATA_LEN_RANGE);
        }

        return (CRYPTO_SUCCESS);
}

/*
 * Helper MD4 digest final function for uio data.
 * digest_len is the length of the desired digest. If digest_len
 * is smaller than the default MD4 digest length, the caller
 * must pass a scratch buffer, digest_scratch, which must
 * be at least MD4_DIGEST_LENGTH bytes.
 */
static int
md4_digest_final_uio(MD4_CTX *md4_ctx, crypto_data_t *digest,
    ulong_t digest_len, uchar_t *digest_scratch)
{
        off_t offset = digest->cd_offset;
        uint_t vec_idx;

        /* we support only kernel buffer */
        if (digest->cd_uio->uio_segflg != UIO_SYSSPACE)
                return (CRYPTO_ARGUMENTS_BAD);

        /*
         * Jump to the first iovec containing ptr to the digest to
         * be returned.
         */
        for (vec_idx = 0; offset >= digest->cd_uio->uio_iov[vec_idx].iov_len &&
            vec_idx < digest->cd_uio->uio_iovcnt;
            offset -= digest->cd_uio->uio_iov[vec_idx++].iov_len)
                ;
        if (vec_idx == digest->cd_uio->uio_iovcnt) {
                /*
                 * The caller specified an offset that is
                 * larger than the total size of the buffers
                 * it provided.
                 */
                return (CRYPTO_DATA_LEN_RANGE);
        }

        if (offset + digest_len <=
            digest->cd_uio->uio_iov[vec_idx].iov_len) {
                /*
                 * The computed MD4 digest will fit in the current
                 * iovec.
                 */
                if (digest_len != MD4_DIGEST_LENGTH) {
                        /*
                         * The caller requested a short digest. Digest
                         * into a scratch buffer and return to
                         * the user only what was requested.
                         */
                        MD4Final(digest_scratch, md4_ctx);
                        bcopy(digest_scratch, (uchar_t *)digest->
                            cd_uio->uio_iov[vec_idx].iov_base + offset,
                            digest_len);
                } else {
                        MD4Final((uchar_t *)digest->
                            cd_uio->uio_iov[vec_idx].iov_base + offset,
                            md4_ctx);
                }
        } else {
                /*
                 * The computed digest will be crossing one or more iovec's.
                 * This is bad performance-wise but we need to support it.
                 * Allocate a small scratch buffer on the stack and
                 * copy it piece meal to the specified digest iovec's.
                 */
                uchar_t digest_tmp[MD4_DIGEST_LENGTH];
                off_t scratch_offset = 0;
                size_t length = digest_len;
                size_t cur_len;

                MD4Final(digest_tmp, md4_ctx);

                while (vec_idx < digest->cd_uio->uio_iovcnt && length > 0) {
                        cur_len = MIN(digest->cd_uio->uio_iov[vec_idx].iov_len -
                            offset, length);
                        bcopy(digest_tmp + scratch_offset,
                            digest->cd_uio->uio_iov[vec_idx].iov_base + offset,
                            cur_len);

                        length -= cur_len;
                        vec_idx++;
                        scratch_offset += cur_len;
                        offset = 0;
                }

                if (vec_idx == digest->cd_uio->uio_iovcnt && length > 0) {
                        /*
                         * The end of the specified iovec's was reached but
                         * the length requested could not be processed, i.e.
                         * The caller requested to digest more data than it
                         * provided.
                         */
                        return (CRYPTO_DATA_LEN_RANGE);
                }
        }

        return (CRYPTO_SUCCESS);
}

/*
 * Helper MD4 digest update for mblk's.
 */
static int
md4_digest_update_mblk(MD4_CTX *md4_ctx, crypto_data_t *data)
{
        off_t offset = data->cd_offset;
        size_t length = data->cd_length;
        mblk_t *mp;
        size_t cur_len;

        /*
         * Jump to the first mblk_t containing data to be digested.
         */
        for (mp = data->cd_mp; mp != NULL && offset >= MBLKL(mp);
            offset -= MBLKL(mp), mp = mp->b_cont)
                ;
        if (mp == NULL) {
                /*
                 * The caller specified an offset that is larger than the
                 * total size of the buffers it provided.
                 */
                return (CRYPTO_DATA_LEN_RANGE);
        }

        /*
         * Now do the digesting on the mblk chain.
         */
        while (mp != NULL && length > 0) {
                cur_len = MIN(MBLKL(mp) - offset, length);
                MD4Update(md4_ctx, mp->b_rptr + offset, cur_len);
                length -= cur_len;
                offset = 0;
                mp = mp->b_cont;
        }

        if (mp == NULL && length > 0) {
                /*
                 * The end of the mblk was reached but the length requested
                 * could not be processed, i.e. The caller requested
                 * to digest more data than it provided.
                 */
                return (CRYPTO_DATA_LEN_RANGE);
        }

        return (CRYPTO_SUCCESS);
}

/*
 * Helper MD4 digest final for mblk's.
 * digest_len is the length of the desired digest. If digest_len
 * is smaller than the default MD4 digest length, the caller
 * must pass a scratch buffer, digest_scratch, which must
 * be at least MD4_DIGEST_LENGTH bytes.
 */
static int
md4_digest_final_mblk(MD4_CTX *md4_ctx, crypto_data_t *digest,
    ulong_t digest_len, uchar_t *digest_scratch)
{
        off_t offset = digest->cd_offset;
        mblk_t *mp;

        /*
         * Jump to the first mblk_t that will be used to store the digest.
         */
        for (mp = digest->cd_mp; mp != NULL && offset >= MBLKL(mp);
            offset -= MBLKL(mp), mp = mp->b_cont)
                ;
        if (mp == NULL) {
                /*
                 * The caller specified an offset that is larger than the
                 * total size of the buffers it provided.
                 */
                return (CRYPTO_DATA_LEN_RANGE);
        }

        if (offset + digest_len <= MBLKL(mp)) {
                /*
                 * The computed MD4 digest will fit in the current mblk.
                 * Do the MD4Final() in-place.
                 */
                if (digest_len != MD4_DIGEST_LENGTH) {
                        /*
                         * The caller requested a short digest. Digest
                         * into a scratch buffer and return to
                         * the user only what was requested.
                         */
                        MD4Final(digest_scratch, md4_ctx);
                        bcopy(digest_scratch, mp->b_rptr + offset, digest_len);
                } else {
                        MD4Final(mp->b_rptr + offset, md4_ctx);
                }
        } else {
                /*
                 * The computed digest will be crossing one or more mblk's.
                 * This is bad performance-wise but we need to support it.
                 * Allocate a small scratch buffer on the stack and
                 * copy it piece meal to the specified digest iovec's.
                 */
                uchar_t digest_tmp[MD4_DIGEST_LENGTH];
                off_t scratch_offset = 0;
                size_t length = digest_len;
                size_t cur_len;

                MD4Final(digest_tmp, md4_ctx);

                while (mp != NULL && length > 0) {
                        cur_len = MIN(MBLKL(mp) - offset, length);
                        bcopy(digest_tmp + scratch_offset,
                            mp->b_rptr + offset, cur_len);

                        length -= cur_len;
                        mp = mp->b_cont;
                        scratch_offset += cur_len;
                        offset = 0;
                }

                if (mp == NULL && length > 0) {
                        /*
                         * The end of the specified mblk was reached but
                         * the length requested could not be processed, i.e.
                         * The caller requested to digest more data than it
                         * provided.
                         */
                        return (CRYPTO_DATA_LEN_RANGE);
                }
        }

        return (CRYPTO_SUCCESS);
}

/* ARGSUSED */
static int
md4_digest(crypto_ctx_t *ctx, crypto_data_t *data, crypto_data_t *digest,
    crypto_req_handle_t req)
{
        int ret = CRYPTO_SUCCESS;

        ASSERT(ctx->cc_provider_private != NULL);

        /*
         * We need to just return the length needed to store the output.
         * We should not destroy the context for the following cases.
         */
        if ((digest->cd_length == 0) ||
            (digest->cd_length < MD4_DIGEST_LENGTH)) {
                digest->cd_length = MD4_DIGEST_LENGTH;
                return (CRYPTO_BUFFER_TOO_SMALL);
        }

        /*
         * Do the MD4 update on the specified input data.
         */
        switch (data->cd_format) {
        case CRYPTO_DATA_RAW:
                MD4Update(&PROV_MD4_CTX(ctx)->mc_md4_ctx,
                    data->cd_raw.iov_base + data->cd_offset,
                    data->cd_length);
                break;
        case CRYPTO_DATA_UIO:
                ret = md4_digest_update_uio(&PROV_MD4_CTX(ctx)->mc_md4_ctx,
                    data);
                break;
        case CRYPTO_DATA_MBLK:
                ret = md4_digest_update_mblk(&PROV_MD4_CTX(ctx)->mc_md4_ctx,
                    data);
                break;
        default:
                ret = CRYPTO_ARGUMENTS_BAD;
        }

        if (ret != CRYPTO_SUCCESS) {
                /* the update failed, free context and bail */
                kmem_free(ctx->cc_provider_private, sizeof (md4_ctx_t));
                ctx->cc_provider_private = NULL;
                digest->cd_length = 0;
                return (ret);
        }

        /*
         * Do an MD4 final, must be done separately since the digest
         * type can be different than the input data type.
         */
        switch (digest->cd_format) {
        case CRYPTO_DATA_RAW:
                MD4Final((unsigned char *)digest->cd_raw.iov_base +
                    digest->cd_offset, &PROV_MD4_CTX(ctx)->mc_md4_ctx);
                break;
        case CRYPTO_DATA_UIO:
                ret = md4_digest_final_uio(&PROV_MD4_CTX(ctx)->mc_md4_ctx,
                    digest, MD4_DIGEST_LENGTH, NULL);
                break;
        case CRYPTO_DATA_MBLK:
                ret = md4_digest_final_mblk(&PROV_MD4_CTX(ctx)->mc_md4_ctx,
                    digest, MD4_DIGEST_LENGTH, NULL);
                break;
        default:
                ret = CRYPTO_ARGUMENTS_BAD;
        }

        /* all done, free context and return */

        if (ret == CRYPTO_SUCCESS) {
                digest->cd_length = MD4_DIGEST_LENGTH;
        } else {
                digest->cd_length = 0;
        }

        kmem_free(ctx->cc_provider_private, sizeof (md4_ctx_t));
        ctx->cc_provider_private = NULL;
        return (ret);
}

/* ARGSUSED */
static int
md4_digest_update(crypto_ctx_t *ctx, crypto_data_t *data,
    crypto_req_handle_t req)
{
        int ret = CRYPTO_SUCCESS;

        ASSERT(ctx->cc_provider_private != NULL);

        /*
         * Do the MD4 update on the specified input data.
         */
        switch (data->cd_format) {
        case CRYPTO_DATA_RAW:
                MD4Update(&PROV_MD4_CTX(ctx)->mc_md4_ctx,
                    data->cd_raw.iov_base + data->cd_offset,
                    data->cd_length);
                break;
        case CRYPTO_DATA_UIO:
                ret = md4_digest_update_uio(&PROV_MD4_CTX(ctx)->mc_md4_ctx,
                    data);
                break;
        case CRYPTO_DATA_MBLK:
                ret = md4_digest_update_mblk(&PROV_MD4_CTX(ctx)->mc_md4_ctx,
                    data);
                break;
        default:
                ret = CRYPTO_ARGUMENTS_BAD;
        }

        return (ret);
}

/* ARGSUSED */
static int
md4_digest_final(crypto_ctx_t *ctx, crypto_data_t *digest,
    crypto_req_handle_t req)
{
        int ret = CRYPTO_SUCCESS;

        ASSERT(ctx->cc_provider_private != NULL);

        /*
         * We need to just return the length needed to store the output.
         * We should not destroy the context for the following cases.
         */
        if ((digest->cd_length == 0) ||
            (digest->cd_length < MD4_DIGEST_LENGTH)) {
                digest->cd_length = MD4_DIGEST_LENGTH;
                return (CRYPTO_BUFFER_TOO_SMALL);
        }

        /*
         * Do an MD4 final.
         */
        switch (digest->cd_format) {
        case CRYPTO_DATA_RAW:
                MD4Final((unsigned char *)digest->cd_raw.iov_base +
                    digest->cd_offset, &PROV_MD4_CTX(ctx)->mc_md4_ctx);
                break;
        case CRYPTO_DATA_UIO:
                ret = md4_digest_final_uio(&PROV_MD4_CTX(ctx)->mc_md4_ctx,
                    digest, MD4_DIGEST_LENGTH, NULL);
                break;
        case CRYPTO_DATA_MBLK:
                ret = md4_digest_final_mblk(&PROV_MD4_CTX(ctx)->mc_md4_ctx,
                    digest, MD4_DIGEST_LENGTH, NULL);
                break;
        default:
                ret = CRYPTO_ARGUMENTS_BAD;
        }

        /* all done, free context and return */

        if (ret == CRYPTO_SUCCESS) {
                digest->cd_length = MD4_DIGEST_LENGTH;
        } else {
                digest->cd_length = 0;
        }

        kmem_free(ctx->cc_provider_private, sizeof (md4_ctx_t));
        ctx->cc_provider_private = NULL;

        return (ret);
}

/* ARGSUSED */
static int
md4_digest_atomic(crypto_provider_handle_t provider,
    crypto_session_id_t session_id, crypto_mechanism_t *mechanism,
    crypto_data_t *data, crypto_data_t *digest,
    crypto_req_handle_t req)
{
        int ret = CRYPTO_SUCCESS;
        MD4_CTX md4_ctx;

        if (mechanism->cm_type != MD4_MECH_INFO_TYPE)
                return (CRYPTO_MECHANISM_INVALID);

        /*
         * Do the MD4 init.
         */
        MD4Init(&md4_ctx);

        /*
         * Do the MD4 update on the specified input data.
         */
        switch (data->cd_format) {
        case CRYPTO_DATA_RAW:
                MD4Update(&md4_ctx, data->cd_raw.iov_base + data->cd_offset,
                    data->cd_length);
                break;
        case CRYPTO_DATA_UIO:
                ret = md4_digest_update_uio(&md4_ctx, data);
                break;
        case CRYPTO_DATA_MBLK:
                ret = md4_digest_update_mblk(&md4_ctx, data);
                break;
        default:
                ret = CRYPTO_ARGUMENTS_BAD;
        }

        if (ret != CRYPTO_SUCCESS) {
                /* the update failed, bail */
                digest->cd_length = 0;
                return (ret);
        }

        /*
         * Do an MD4 final, must be done separately since the digest
         * type can be different than the input data type.
         */
        switch (digest->cd_format) {
        case CRYPTO_DATA_RAW:
                MD4Final((unsigned char *)digest->cd_raw.iov_base +
                    digest->cd_offset, &md4_ctx);
                break;
        case CRYPTO_DATA_UIO:
                ret = md4_digest_final_uio(&md4_ctx, digest,
                    MD4_DIGEST_LENGTH, NULL);
                break;
        case CRYPTO_DATA_MBLK:
                ret = md4_digest_final_mblk(&md4_ctx, digest,
                    MD4_DIGEST_LENGTH, NULL);
                break;
        default:
                ret = CRYPTO_ARGUMENTS_BAD;
        }

        if (ret == CRYPTO_SUCCESS) {
                digest->cd_length = MD4_DIGEST_LENGTH;
        } else {
                digest->cd_length = 0;
        }

        return (ret);
}