OpenZFS 4185 - add new cryptographic checksums to ZFS: SHA-512, Skein, Edon-R

[mirror_zfs.git] / module / icp / io / sha2_mod.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.
 */

#include <sys/zfs_context.h>
#include <sys/modctl.h>
#include <sys/crypto/common.h>
#include <sys/crypto/spi.h>
#include <sys/crypto/icp.h>
#define _SHA2_IMPL
#include <sys/sha2.h>
#include <sha2/sha2_impl.h>

/*
 * The sha2 module is created with two modlinkages:
 * - a modlmisc that allows consumers to directly call the entry points
 *   SHA2Init, SHA2Update, and SHA2Final.
 * - a modlcrypto that allows the module to register with the Kernel
 *   Cryptographic Framework (KCF) as a software provider for the SHA2
 *   mechanisms.
 */

static struct modlcrypto modlcrypto = {
        &mod_cryptoops,
        "SHA2 Kernel SW Provider"
};

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

/*
 * Macros to access the SHA2 or SHA2-HMAC contexts from a context passed
 * by KCF to one of the entry points.
 */

#define PROV_SHA2_CTX(ctx)      ((sha2_ctx_t *)(ctx)->cc_provider_private)
#define PROV_SHA2_HMAC_CTX(ctx) ((sha2_hmac_ctx_t *)(ctx)->cc_provider_private)

/* to extract the digest length passed as mechanism parameter */
#define PROV_SHA2_GET_DIGEST_LEN(m, len) {                              \
        if (IS_P2ALIGNED((m)->cm_param, sizeof (ulong_t)))              \
                (len) = (uint32_t)*((ulong_t *)(m)->cm_param);  \
        else {                                                          \
                ulong_t tmp_ulong;                                      \
                bcopy((m)->cm_param, &tmp_ulong, sizeof (ulong_t));     \
                (len) = (uint32_t)tmp_ulong;                            \
        }                                                               \
}

#define PROV_SHA2_DIGEST_KEY(mech, ctx, key, len, digest) {     \
        SHA2Init(mech, ctx);                            \
        SHA2Update(ctx, key, len);                      \
        SHA2Final(digest, ctx);                         \
}

/*
 * Mechanism info structure passed to KCF during registration.
 */
static crypto_mech_info_t sha2_mech_info_tab[] = {
        /* SHA256 */
        {SUN_CKM_SHA256, SHA256_MECH_INFO_TYPE,
            CRYPTO_FG_DIGEST | CRYPTO_FG_DIGEST_ATOMIC,
            0, 0, CRYPTO_KEYSIZE_UNIT_IN_BITS},
        /* SHA256-HMAC */
        {SUN_CKM_SHA256_HMAC, SHA256_HMAC_MECH_INFO_TYPE,
            CRYPTO_FG_MAC | CRYPTO_FG_MAC_ATOMIC,
            SHA2_HMAC_MIN_KEY_LEN, SHA2_HMAC_MAX_KEY_LEN,
            CRYPTO_KEYSIZE_UNIT_IN_BYTES},
        /* SHA256-HMAC GENERAL */
        {SUN_CKM_SHA256_HMAC_GENERAL, SHA256_HMAC_GEN_MECH_INFO_TYPE,
            CRYPTO_FG_MAC | CRYPTO_FG_MAC_ATOMIC,
            SHA2_HMAC_MIN_KEY_LEN, SHA2_HMAC_MAX_KEY_LEN,
            CRYPTO_KEYSIZE_UNIT_IN_BYTES}
};

static void sha2_provider_status(crypto_provider_handle_t, uint_t *);

static crypto_control_ops_t sha2_control_ops = {
        sha2_provider_status
};

static int sha2_digest_init(crypto_ctx_t *, crypto_mechanism_t *,
    crypto_req_handle_t);
static int sha2_digest(crypto_ctx_t *, crypto_data_t *, crypto_data_t *,
    crypto_req_handle_t);
static int sha2_digest_update(crypto_ctx_t *, crypto_data_t *,
    crypto_req_handle_t);
static int sha2_digest_final(crypto_ctx_t *, crypto_data_t *,
    crypto_req_handle_t);
static int sha2_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 sha2_digest_ops = {
        sha2_digest_init,
        sha2_digest,
        sha2_digest_update,
        NULL,
        sha2_digest_final,
        sha2_digest_atomic
};

static int sha2_mac_init(crypto_ctx_t *, crypto_mechanism_t *, crypto_key_t *,
    crypto_spi_ctx_template_t, crypto_req_handle_t);
static int sha2_mac_update(crypto_ctx_t *, crypto_data_t *,
    crypto_req_handle_t);
static int sha2_mac_final(crypto_ctx_t *, crypto_data_t *, crypto_req_handle_t);
static int sha2_mac_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 sha2_mac_verify_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_mac_ops_t sha2_mac_ops = {
        sha2_mac_init,
        NULL,
        sha2_mac_update,
        sha2_mac_final,
        sha2_mac_atomic,
        sha2_mac_verify_atomic
};

static int sha2_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 sha2_free_context(crypto_ctx_t *);

static crypto_ctx_ops_t sha2_ctx_ops = {
        sha2_create_ctx_template,
        sha2_free_context
};

static crypto_ops_t sha2_crypto_ops = {{{{{
        &sha2_control_ops,
        &sha2_digest_ops,
        NULL,
        &sha2_mac_ops,
        NULL,
        NULL,
        NULL,
        NULL,
        NULL,
        NULL,
        NULL,
        NULL,
        NULL,
        &sha2_ctx_ops
}}}}};

static crypto_provider_info_t sha2_prov_info = {{{{
        CRYPTO_SPI_VERSION_1,
        "SHA2 Software Provider",
        CRYPTO_SW_PROVIDER,
        NULL,
        &sha2_crypto_ops,
        sizeof (sha2_mech_info_tab)/sizeof (crypto_mech_info_t),
        sha2_mech_info_tab
}}}};

static crypto_kcf_provider_handle_t sha2_prov_handle = 0;

int
sha2_mod_init(void)
{
        int ret;

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

        /*
         * Register with KCF. If the registration fails, log an
         * error but do not uninstall the module, since the functionality
         * provided by misc/sha2 should still be available.
         */
        if ((ret = crypto_register_provider(&sha2_prov_info,
            &sha2_prov_handle)) != CRYPTO_SUCCESS)
                cmn_err(CE_WARN, "sha2 _init: "
                    "crypto_register_provider() failed (0x%x)", ret);

        return (0);
}

int
sha2_mod_fini(void)
{
        int ret;

        if (sha2_prov_handle != 0) {
                if ((ret = crypto_unregister_provider(sha2_prov_handle)) !=
                    CRYPTO_SUCCESS) {
                        cmn_err(CE_WARN,
                            "sha2 _fini: crypto_unregister_provider() "
                            "failed (0x%x)", ret);
                        return (EBUSY);
                }
                sha2_prov_handle = 0;
        }

        return (mod_remove(&modlinkage));
}

/*
 * KCF software provider control entry points.
 */
/* ARGSUSED */
static void
sha2_provider_status(crypto_provider_handle_t provider, uint_t *status)
{
        *status = CRYPTO_PROVIDER_READY;
}

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

static int
sha2_digest_init(crypto_ctx_t *ctx, crypto_mechanism_t *mechanism,
    crypto_req_handle_t req)
{

        /*
         * Allocate and initialize SHA2 context.
         */
        ctx->cc_provider_private = kmem_alloc(sizeof (sha2_ctx_t),
            crypto_kmflag(req));
        if (ctx->cc_provider_private == NULL)
                return (CRYPTO_HOST_MEMORY);

        PROV_SHA2_CTX(ctx)->sc_mech_type = mechanism->cm_type;
        SHA2Init(mechanism->cm_type, &PROV_SHA2_CTX(ctx)->sc_sha2_ctx);

        return (CRYPTO_SUCCESS);
}

/*
 * Helper SHA2 digest update function for uio data.
 */
static int
sha2_digest_update_uio(SHA2_CTX *sha2_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);

                SHA2Update(sha2_ctx, (uint8_t *)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 SHA2 digest final function for uio data.
 * digest_len is the length of the desired digest. If digest_len
 * is smaller than the default SHA2 digest length, the caller
 * must pass a scratch buffer, digest_scratch, which must
 * be at least the algorithm's digest length bytes.
 */
static int
sha2_digest_final_uio(SHA2_CTX *sha2_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 SHA2 digest will fit in the current
                 * iovec.
                 */
                if (((sha2_ctx->algotype <= SHA256_HMAC_GEN_MECH_INFO_TYPE) &&
                    (digest_len != SHA256_DIGEST_LENGTH))) {
                        /*
                         * The caller requested a short digest. Digest
                         * into a scratch buffer and return to
                         * the user only what was requested.
                         */
                        SHA2Final(digest_scratch, sha2_ctx);

                        bcopy(digest_scratch, (uchar_t *)digest->
                            cd_uio->uio_iov[vec_idx].iov_base + offset,
                            digest_len);
                } else {
                        SHA2Final((uchar_t *)digest->
                            cd_uio->uio_iov[vec_idx].iov_base + offset,
                            sha2_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[SHA256_DIGEST_LENGTH];
                off_t scratch_offset = 0;
                size_t length = digest_len;
                size_t cur_len;

                SHA2Final(digest_tmp, sha2_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);
}

/* ARGSUSED */
static int
sha2_digest(crypto_ctx_t *ctx, crypto_data_t *data, crypto_data_t *digest,
    crypto_req_handle_t req)
{
        int ret = CRYPTO_SUCCESS;
        uint_t sha_digest_len;

        ASSERT(ctx->cc_provider_private != NULL);

        switch (PROV_SHA2_CTX(ctx)->sc_mech_type) {
        case SHA256_MECH_INFO_TYPE:
                sha_digest_len = SHA256_DIGEST_LENGTH;
                break;
        default:
                return (CRYPTO_MECHANISM_INVALID);
        }

        /*
         * 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 < sha_digest_len)) {
                digest->cd_length = sha_digest_len;
                return (CRYPTO_BUFFER_TOO_SMALL);
        }

        /*
         * Do the SHA2 update on the specified input data.
         */
        switch (data->cd_format) {
        case CRYPTO_DATA_RAW:
                SHA2Update(&PROV_SHA2_CTX(ctx)->sc_sha2_ctx,
                    (uint8_t *)data->cd_raw.iov_base + data->cd_offset,
                    data->cd_length);
                break;
        case CRYPTO_DATA_UIO:
                ret = sha2_digest_update_uio(&PROV_SHA2_CTX(ctx)->sc_sha2_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 (sha2_ctx_t));
                ctx->cc_provider_private = NULL;
                digest->cd_length = 0;
                return (ret);
        }

        /*
         * Do a SHA2 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:
                SHA2Final((unsigned char *)digest->cd_raw.iov_base +
                    digest->cd_offset, &PROV_SHA2_CTX(ctx)->sc_sha2_ctx);
                break;
        case CRYPTO_DATA_UIO:
                ret = sha2_digest_final_uio(&PROV_SHA2_CTX(ctx)->sc_sha2_ctx,
                    digest, sha_digest_len, NULL);
                break;
        default:
                ret = CRYPTO_ARGUMENTS_BAD;
        }

        /* all done, free context and return */

        if (ret == CRYPTO_SUCCESS)
                digest->cd_length = sha_digest_len;
        else
                digest->cd_length = 0;

        kmem_free(ctx->cc_provider_private, sizeof (sha2_ctx_t));
        ctx->cc_provider_private = NULL;
        return (ret);
}

/* ARGSUSED */
static int
sha2_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 SHA2 update on the specified input data.
         */
        switch (data->cd_format) {
        case CRYPTO_DATA_RAW:
                SHA2Update(&PROV_SHA2_CTX(ctx)->sc_sha2_ctx,
                    (uint8_t *)data->cd_raw.iov_base + data->cd_offset,
                    data->cd_length);
                break;
        case CRYPTO_DATA_UIO:
                ret = sha2_digest_update_uio(&PROV_SHA2_CTX(ctx)->sc_sha2_ctx,
                    data);
                break;
        default:
                ret = CRYPTO_ARGUMENTS_BAD;
        }

        return (ret);
}

/* ARGSUSED */
static int
sha2_digest_final(crypto_ctx_t *ctx, crypto_data_t *digest,
    crypto_req_handle_t req)
{
        int ret = CRYPTO_SUCCESS;
        uint_t sha_digest_len;

        ASSERT(ctx->cc_provider_private != NULL);

        switch (PROV_SHA2_CTX(ctx)->sc_mech_type) {
        case SHA256_MECH_INFO_TYPE:
                sha_digest_len = SHA256_DIGEST_LENGTH;
                break;
        default:
                return (CRYPTO_MECHANISM_INVALID);
        }

        /*
         * 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 < sha_digest_len)) {
                digest->cd_length = sha_digest_len;
                return (CRYPTO_BUFFER_TOO_SMALL);
        }

        /*
         * Do a SHA2 final.
         */
        switch (digest->cd_format) {
        case CRYPTO_DATA_RAW:
                SHA2Final((unsigned char *)digest->cd_raw.iov_base +
                    digest->cd_offset, &PROV_SHA2_CTX(ctx)->sc_sha2_ctx);
                break;
        case CRYPTO_DATA_UIO:
                ret = sha2_digest_final_uio(&PROV_SHA2_CTX(ctx)->sc_sha2_ctx,
                    digest, sha_digest_len, NULL);
                break;
        default:
                ret = CRYPTO_ARGUMENTS_BAD;
        }

        /* all done, free context and return */

        if (ret == CRYPTO_SUCCESS)
                digest->cd_length = sha_digest_len;
        else
                digest->cd_length = 0;

        kmem_free(ctx->cc_provider_private, sizeof (sha2_ctx_t));
        ctx->cc_provider_private = NULL;

        return (ret);
}

/* ARGSUSED */
static int
sha2_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;
        SHA2_CTX sha2_ctx;
        uint32_t sha_digest_len;

        /*
         * Do the SHA inits.
         */

        SHA2Init(mechanism->cm_type, &sha2_ctx);

        switch (data->cd_format) {
        case CRYPTO_DATA_RAW:
                SHA2Update(&sha2_ctx, (uint8_t *)data->
                    cd_raw.iov_base + data->cd_offset, data->cd_length);
                break;
        case CRYPTO_DATA_UIO:
                ret = sha2_digest_update_uio(&sha2_ctx, data);
                break;
        default:
                ret = CRYPTO_ARGUMENTS_BAD;
        }

        /*
         * Do the SHA updates on the specified input data.
         */

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

        if (mechanism->cm_type <= SHA256_HMAC_GEN_MECH_INFO_TYPE)
                sha_digest_len = SHA256_DIGEST_LENGTH;

        /*
         * Do a SHA2 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:
                SHA2Final((unsigned char *)digest->cd_raw.iov_base +
                    digest->cd_offset, &sha2_ctx);
                break;
        case CRYPTO_DATA_UIO:
                ret = sha2_digest_final_uio(&sha2_ctx, digest,
                    sha_digest_len, NULL);
                break;
        default:
                ret = CRYPTO_ARGUMENTS_BAD;
        }

        if (ret == CRYPTO_SUCCESS)
                digest->cd_length = sha_digest_len;
        else
                digest->cd_length = 0;

        return (ret);
}

/*
 * KCF software provider mac entry points.
 *
 * SHA2 HMAC is: SHA2(key XOR opad, SHA2(key XOR ipad, text))
 *
 * Init:
 * The initialization routine initializes what we denote
 * as the inner and outer contexts by doing
 * - for inner context: SHA2(key XOR ipad)
 * - for outer context: SHA2(key XOR opad)
 *
 * Update:
 * Each subsequent SHA2 HMAC update will result in an
 * update of the inner context with the specified data.
 *
 * Final:
 * The SHA2 HMAC final will do a SHA2 final operation on the
 * inner context, and the resulting digest will be used
 * as the data for an update on the outer context. Last
 * but not least, a SHA2 final on the outer context will
 * be performed to obtain the SHA2 HMAC digest to return
 * to the user.
 */

/*
 * Initialize a SHA2-HMAC context.
 */
static void
sha2_mac_init_ctx(sha2_hmac_ctx_t *ctx, void *keyval, uint_t length_in_bytes)
{
        uint64_t ipad[SHA256_HMAC_BLOCK_SIZE / sizeof (uint64_t)];
        uint64_t opad[SHA256_HMAC_BLOCK_SIZE / sizeof (uint64_t)];
        int i, block_size = 0, blocks_per_int64 = 0;

        /* Determine the block size */
        if (ctx->hc_mech_type <= SHA256_HMAC_GEN_MECH_INFO_TYPE) {
                block_size = SHA256_HMAC_BLOCK_SIZE;
                blocks_per_int64 = SHA256_HMAC_BLOCK_SIZE / sizeof (uint64_t);
        }

        (void) bzero(ipad, block_size);
        (void) bzero(opad, block_size);
        (void) bcopy(keyval, ipad, length_in_bytes);
        (void) bcopy(keyval, opad, length_in_bytes);

        /* XOR key with ipad (0x36) and opad (0x5c) */
        for (i = 0; i < blocks_per_int64; i ++) {
                ipad[i] ^= 0x3636363636363636;
                opad[i] ^= 0x5c5c5c5c5c5c5c5c;
        }

        /* perform SHA2 on ipad */
        SHA2Init(ctx->hc_mech_type, &ctx->hc_icontext);
        SHA2Update(&ctx->hc_icontext, (uint8_t *)ipad, block_size);

        /* perform SHA2 on opad */
        SHA2Init(ctx->hc_mech_type, &ctx->hc_ocontext);
        SHA2Update(&ctx->hc_ocontext, (uint8_t *)opad, block_size);

}

/*
 */
static int
sha2_mac_init(crypto_ctx_t *ctx, crypto_mechanism_t *mechanism,
    crypto_key_t *key, crypto_spi_ctx_template_t ctx_template,
    crypto_req_handle_t req)
{
        int ret = CRYPTO_SUCCESS;
        uint_t keylen_in_bytes = CRYPTO_BITS2BYTES(key->ck_length);
        uint_t sha_digest_len, sha_hmac_block_size;

        /*
         * Set the digest length and block size to values approriate to the
         * mechanism
         */
        switch (mechanism->cm_type) {
        case SHA256_HMAC_MECH_INFO_TYPE:
        case SHA256_HMAC_GEN_MECH_INFO_TYPE:
                sha_digest_len = SHA256_DIGEST_LENGTH;
                sha_hmac_block_size = SHA256_HMAC_BLOCK_SIZE;
                break;
        default:
                return (CRYPTO_MECHANISM_INVALID);
        }

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

        ctx->cc_provider_private = kmem_alloc(sizeof (sha2_hmac_ctx_t),
            crypto_kmflag(req));
        if (ctx->cc_provider_private == NULL)
                return (CRYPTO_HOST_MEMORY);

        PROV_SHA2_HMAC_CTX(ctx)->hc_mech_type = mechanism->cm_type;
        if (ctx_template != NULL) {
                /* reuse context template */
                bcopy(ctx_template, PROV_SHA2_HMAC_CTX(ctx),
                    sizeof (sha2_hmac_ctx_t));
        } else {
                /* no context template, compute context */
                if (keylen_in_bytes > sha_hmac_block_size) {
                        uchar_t digested_key[SHA256_DIGEST_LENGTH];
                        sha2_hmac_ctx_t *hmac_ctx = ctx->cc_provider_private;

                        /*
                         * Hash the passed-in key to get a smaller key.
                         * The inner context is used since it hasn't been
                         * initialized yet.
                         */
                        PROV_SHA2_DIGEST_KEY(mechanism->cm_type / 3,
                            &hmac_ctx->hc_icontext,
                            key->ck_data, keylen_in_bytes, digested_key);
                        sha2_mac_init_ctx(PROV_SHA2_HMAC_CTX(ctx),
                            digested_key, sha_digest_len);
                } else {
                        sha2_mac_init_ctx(PROV_SHA2_HMAC_CTX(ctx),
                            key->ck_data, keylen_in_bytes);
                }
        }

        /*
         * Get the mechanism parameters, if applicable.
         */
        if (mechanism->cm_type % 3 == 2) {
                if (mechanism->cm_param == NULL ||
                    mechanism->cm_param_len != sizeof (ulong_t))
                        ret = CRYPTO_MECHANISM_PARAM_INVALID;
                PROV_SHA2_GET_DIGEST_LEN(mechanism,
                    PROV_SHA2_HMAC_CTX(ctx)->hc_digest_len);
                if (PROV_SHA2_HMAC_CTX(ctx)->hc_digest_len > sha_digest_len)
                        ret = CRYPTO_MECHANISM_PARAM_INVALID;
        }

        if (ret != CRYPTO_SUCCESS) {
                bzero(ctx->cc_provider_private, sizeof (sha2_hmac_ctx_t));
                kmem_free(ctx->cc_provider_private, sizeof (sha2_hmac_ctx_t));
                ctx->cc_provider_private = NULL;
        }

        return (ret);
}

/* ARGSUSED */
static int
sha2_mac_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 a SHA2 update of the inner context using the specified
         * data.
         */
        switch (data->cd_format) {
        case CRYPTO_DATA_RAW:
                SHA2Update(&PROV_SHA2_HMAC_CTX(ctx)->hc_icontext,
                    (uint8_t *)data->cd_raw.iov_base + data->cd_offset,
                    data->cd_length);
                break;
        case CRYPTO_DATA_UIO:
                ret = sha2_digest_update_uio(
                    &PROV_SHA2_HMAC_CTX(ctx)->hc_icontext, data);
                break;
        default:
                ret = CRYPTO_ARGUMENTS_BAD;
        }

        return (ret);
}

/* ARGSUSED */
static int
sha2_mac_final(crypto_ctx_t *ctx, crypto_data_t *mac, crypto_req_handle_t req)
{
        int ret = CRYPTO_SUCCESS;
        uchar_t digest[SHA256_DIGEST_LENGTH];
        uint32_t digest_len = 0, sha_digest_len = 0;

        ASSERT(ctx->cc_provider_private != NULL);

        /* Set the digest lengths to values approriate to the mechanism */
        switch (PROV_SHA2_HMAC_CTX(ctx)->hc_mech_type) {
        case SHA256_HMAC_MECH_INFO_TYPE:
                sha_digest_len = digest_len = SHA256_DIGEST_LENGTH;
                break;
        case SHA256_HMAC_GEN_MECH_INFO_TYPE:
                sha_digest_len = SHA256_DIGEST_LENGTH;
                digest_len = PROV_SHA2_HMAC_CTX(ctx)->hc_digest_len;
                break;
        default:
                break;
        }

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

        /*
         * Do a SHA2 final on the inner context.
         */
        SHA2Final(digest, &PROV_SHA2_HMAC_CTX(ctx)->hc_icontext);

        /*
         * Do a SHA2 update on the outer context, feeding the inner
         * digest as data.
         */
        SHA2Update(&PROV_SHA2_HMAC_CTX(ctx)->hc_ocontext, digest,
            sha_digest_len);

        /*
         * Do a SHA2 final on the outer context, storing the computing
         * digest in the users buffer.
         */
        switch (mac->cd_format) {
        case CRYPTO_DATA_RAW:
                if (digest_len != sha_digest_len) {
                        /*
                         * The caller requested a short digest. Digest
                         * into a scratch buffer and return to
                         * the user only what was requested.
                         */
                        SHA2Final(digest,
                            &PROV_SHA2_HMAC_CTX(ctx)->hc_ocontext);
                        bcopy(digest, (unsigned char *)mac->cd_raw.iov_base +
                            mac->cd_offset, digest_len);
                } else {
                        SHA2Final((unsigned char *)mac->cd_raw.iov_base +
                            mac->cd_offset,
                            &PROV_SHA2_HMAC_CTX(ctx)->hc_ocontext);
                }
                break;
        case CRYPTO_DATA_UIO:
                ret = sha2_digest_final_uio(
                    &PROV_SHA2_HMAC_CTX(ctx)->hc_ocontext, mac,
                    digest_len, digest);
                break;
        default:
                ret = CRYPTO_ARGUMENTS_BAD;
        }

        if (ret == CRYPTO_SUCCESS)
                mac->cd_length = digest_len;
        else
                mac->cd_length = 0;

        bzero(ctx->cc_provider_private, sizeof (sha2_hmac_ctx_t));
        kmem_free(ctx->cc_provider_private, sizeof (sha2_hmac_ctx_t));
        ctx->cc_provider_private = NULL;

        return (ret);
}

#define SHA2_MAC_UPDATE(data, ctx, ret) {                               \
        switch (data->cd_format) {                                      \
        case CRYPTO_DATA_RAW:                                           \
                SHA2Update(&(ctx).hc_icontext,                          \
                    (uint8_t *)data->cd_raw.iov_base +                  \
                    data->cd_offset, data->cd_length);                  \
                break;                                                  \
        case CRYPTO_DATA_UIO:                                           \
                ret = sha2_digest_update_uio(&(ctx).hc_icontext, data); \
                break;                                                  \
        default:                                                        \
                ret = CRYPTO_ARGUMENTS_BAD;                             \
        }                                                               \
}

/* ARGSUSED */
static int
sha2_mac_atomic(crypto_provider_handle_t provider,
    crypto_session_id_t session_id, crypto_mechanism_t *mechanism,
    crypto_key_t *key, crypto_data_t *data, crypto_data_t *mac,
    crypto_spi_ctx_template_t ctx_template, crypto_req_handle_t req)
{
        int ret = CRYPTO_SUCCESS;
        uchar_t digest[SHA256_DIGEST_LENGTH];
        sha2_hmac_ctx_t sha2_hmac_ctx;
        uint32_t sha_digest_len, digest_len, sha_hmac_block_size;
        uint_t keylen_in_bytes = CRYPTO_BITS2BYTES(key->ck_length);

        /*
         * Set the digest length and block size to values appropriate to the
         * mechanism
         */
        switch (mechanism->cm_type) {
        case SHA256_HMAC_MECH_INFO_TYPE:
        case SHA256_HMAC_GEN_MECH_INFO_TYPE:
                sha_digest_len = digest_len = SHA256_DIGEST_LENGTH;
                sha_hmac_block_size = SHA256_HMAC_BLOCK_SIZE;
                break;
        default:
                return (CRYPTO_MECHANISM_INVALID);
        }

        /* Add support for key by attributes (RFE 4706552) */
        if (key->ck_format != CRYPTO_KEY_RAW)
                return (CRYPTO_ARGUMENTS_BAD);

        if (ctx_template != NULL) {
                /* reuse context template */
                bcopy(ctx_template, &sha2_hmac_ctx, sizeof (sha2_hmac_ctx_t));
        } else {
                sha2_hmac_ctx.hc_mech_type = mechanism->cm_type;
                /* no context template, initialize context */
                if (keylen_in_bytes > sha_hmac_block_size) {
                        /*
                         * Hash the passed-in key to get a smaller key.
                         * The inner context is used since it hasn't been
                         * initialized yet.
                         */
                        PROV_SHA2_DIGEST_KEY(mechanism->cm_type / 3,
                            &sha2_hmac_ctx.hc_icontext,
                            key->ck_data, keylen_in_bytes, digest);
                        sha2_mac_init_ctx(&sha2_hmac_ctx, digest,
                            sha_digest_len);
                } else {
                        sha2_mac_init_ctx(&sha2_hmac_ctx, key->ck_data,
                            keylen_in_bytes);
                }
        }

        /* get the mechanism parameters, if applicable */
        if ((mechanism->cm_type % 3) == 2) {
                if (mechanism->cm_param == NULL ||
                    mechanism->cm_param_len != sizeof (ulong_t)) {
                        ret = CRYPTO_MECHANISM_PARAM_INVALID;
                        goto bail;
                }
                PROV_SHA2_GET_DIGEST_LEN(mechanism, digest_len);
                if (digest_len > sha_digest_len) {
                        ret = CRYPTO_MECHANISM_PARAM_INVALID;
                        goto bail;
                }
        }

        /* do a SHA2 update of the inner context using the specified data */
        SHA2_MAC_UPDATE(data, sha2_hmac_ctx, ret);
        if (ret != CRYPTO_SUCCESS)
                /* the update failed, free context and bail */
                goto bail;

        /*
         * Do a SHA2 final on the inner context.
         */
        SHA2Final(digest, &sha2_hmac_ctx.hc_icontext);

        /*
         * Do an SHA2 update on the outer context, feeding the inner
         * digest as data.
         */
        SHA2Update(&sha2_hmac_ctx.hc_ocontext, digest, sha_digest_len);

        /*
         * Do a SHA2 final on the outer context, storing the computed
         * digest in the users buffer.
         */
        switch (mac->cd_format) {
        case CRYPTO_DATA_RAW:
                if (digest_len != sha_digest_len) {
                        /*
                         * The caller requested a short digest. Digest
                         * into a scratch buffer and return to
                         * the user only what was requested.
                         */
                        SHA2Final(digest, &sha2_hmac_ctx.hc_ocontext);
                        bcopy(digest, (unsigned char *)mac->cd_raw.iov_base +
                            mac->cd_offset, digest_len);
                } else {
                        SHA2Final((unsigned char *)mac->cd_raw.iov_base +
                            mac->cd_offset, &sha2_hmac_ctx.hc_ocontext);
                }
                break;
        case CRYPTO_DATA_UIO:
                ret = sha2_digest_final_uio(&sha2_hmac_ctx.hc_ocontext, mac,
                    digest_len, digest);
                break;
        default:
                ret = CRYPTO_ARGUMENTS_BAD;
        }

        if (ret == CRYPTO_SUCCESS) {
                mac->cd_length = digest_len;
                return (CRYPTO_SUCCESS);
        }
bail:
        bzero(&sha2_hmac_ctx, sizeof (sha2_hmac_ctx_t));
        mac->cd_length = 0;
        return (ret);
}

/* ARGSUSED */
static int
sha2_mac_verify_atomic(crypto_provider_handle_t provider,
    crypto_session_id_t session_id, crypto_mechanism_t *mechanism,
    crypto_key_t *key, crypto_data_t *data, crypto_data_t *mac,
    crypto_spi_ctx_template_t ctx_template, crypto_req_handle_t req)
{
        int ret = CRYPTO_SUCCESS;
        uchar_t digest[SHA256_DIGEST_LENGTH];
        sha2_hmac_ctx_t sha2_hmac_ctx;
        uint32_t sha_digest_len, digest_len, sha_hmac_block_size;
        uint_t keylen_in_bytes = CRYPTO_BITS2BYTES(key->ck_length);

        /*
         * Set the digest length and block size to values appropriate to the
         * mechanism
         */
        switch (mechanism->cm_type) {
        case SHA256_HMAC_MECH_INFO_TYPE:
        case SHA256_HMAC_GEN_MECH_INFO_TYPE:
                sha_digest_len = digest_len = SHA256_DIGEST_LENGTH;
                sha_hmac_block_size = SHA256_HMAC_BLOCK_SIZE;
                break;
        default:
                return (CRYPTO_MECHANISM_INVALID);
        }

        /* Add support for key by attributes (RFE 4706552) */
        if (key->ck_format != CRYPTO_KEY_RAW)
                return (CRYPTO_ARGUMENTS_BAD);

        if (ctx_template != NULL) {
                /* reuse context template */
                bcopy(ctx_template, &sha2_hmac_ctx, sizeof (sha2_hmac_ctx_t));
        } else {
                sha2_hmac_ctx.hc_mech_type = mechanism->cm_type;
                /* no context template, initialize context */
                if (keylen_in_bytes > sha_hmac_block_size) {
                        /*
                         * Hash the passed-in key to get a smaller key.
                         * The inner context is used since it hasn't been
                         * initialized yet.
                         */
                        PROV_SHA2_DIGEST_KEY(mechanism->cm_type / 3,
                            &sha2_hmac_ctx.hc_icontext,
                            key->ck_data, keylen_in_bytes, digest);
                        sha2_mac_init_ctx(&sha2_hmac_ctx, digest,
                            sha_digest_len);
                } else {
                        sha2_mac_init_ctx(&sha2_hmac_ctx, key->ck_data,
                            keylen_in_bytes);
                }
        }

        /* get the mechanism parameters, if applicable */
        if (mechanism->cm_type % 3 == 2) {
                if (mechanism->cm_param == NULL ||
                    mechanism->cm_param_len != sizeof (ulong_t)) {
                        ret = CRYPTO_MECHANISM_PARAM_INVALID;
                        goto bail;
                }
                PROV_SHA2_GET_DIGEST_LEN(mechanism, digest_len);
                if (digest_len > sha_digest_len) {
                        ret = CRYPTO_MECHANISM_PARAM_INVALID;
                        goto bail;
                }
        }

        if (mac->cd_length != digest_len) {
                ret = CRYPTO_INVALID_MAC;
                goto bail;
        }

        /* do a SHA2 update of the inner context using the specified data */
        SHA2_MAC_UPDATE(data, sha2_hmac_ctx, ret);
        if (ret != CRYPTO_SUCCESS)
                /* the update failed, free context and bail */
                goto bail;

        /* do a SHA2 final on the inner context */
        SHA2Final(digest, &sha2_hmac_ctx.hc_icontext);

        /*
         * Do an SHA2 update on the outer context, feeding the inner
         * digest as data.
         */
        SHA2Update(&sha2_hmac_ctx.hc_ocontext, digest, sha_digest_len);

        /*
         * Do a SHA2 final on the outer context, storing the computed
         * digest in the users buffer.
         */
        SHA2Final(digest, &sha2_hmac_ctx.hc_ocontext);

        /*
         * Compare the computed digest against the expected digest passed
         * as argument.
         */

        switch (mac->cd_format) {

        case CRYPTO_DATA_RAW:
                if (bcmp(digest, (unsigned char *)mac->cd_raw.iov_base +
                    mac->cd_offset, digest_len) != 0)
                        ret = CRYPTO_INVALID_MAC;
                break;

        case CRYPTO_DATA_UIO: {
                off_t offset = mac->cd_offset;
                uint_t vec_idx;
                off_t scratch_offset = 0;
                size_t length = digest_len;
                size_t cur_len;

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

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

                /* do the comparison of computed digest vs specified one */
                while (vec_idx < mac->cd_uio->uio_iovcnt && length > 0) {
                        cur_len = MIN(mac->cd_uio->uio_iov[vec_idx].iov_len -
                            offset, length);

                        if (bcmp(digest + scratch_offset,
                            mac->cd_uio->uio_iov[vec_idx].iov_base + offset,
                            cur_len) != 0) {
                                ret = CRYPTO_INVALID_MAC;
                                break;
                        }

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

        default:
                ret = CRYPTO_ARGUMENTS_BAD;
        }

        return (ret);
bail:
        bzero(&sha2_hmac_ctx, sizeof (sha2_hmac_ctx_t));
        mac->cd_length = 0;
        return (ret);
}

/*
 * KCF software provider context management entry points.
 */

/* ARGSUSED */
static int
sha2_create_ctx_template(crypto_provider_handle_t provider,
    crypto_mechanism_t *mechanism, crypto_key_t *key,
    crypto_spi_ctx_template_t *ctx_template, size_t *ctx_template_size,
    crypto_req_handle_t req)
{
        sha2_hmac_ctx_t *sha2_hmac_ctx_tmpl;
        uint_t keylen_in_bytes = CRYPTO_BITS2BYTES(key->ck_length);
        uint32_t sha_digest_len, sha_hmac_block_size;

        /*
         * Set the digest length and block size to values appropriate to the
         * mechanism
         */
        switch (mechanism->cm_type) {
        case SHA256_HMAC_MECH_INFO_TYPE:
        case SHA256_HMAC_GEN_MECH_INFO_TYPE:
                sha_digest_len = SHA256_DIGEST_LENGTH;
                sha_hmac_block_size = SHA256_HMAC_BLOCK_SIZE;
                break;
        default:
                return (CRYPTO_MECHANISM_INVALID);
        }

        /* Add support for key by attributes (RFE 4706552) */
        if (key->ck_format != CRYPTO_KEY_RAW)
                return (CRYPTO_ARGUMENTS_BAD);

        /*
         * Allocate and initialize SHA2 context.
         */
        sha2_hmac_ctx_tmpl = kmem_alloc(sizeof (sha2_hmac_ctx_t),
            crypto_kmflag(req));
        if (sha2_hmac_ctx_tmpl == NULL)
                return (CRYPTO_HOST_MEMORY);

        sha2_hmac_ctx_tmpl->hc_mech_type = mechanism->cm_type;

        if (keylen_in_bytes > sha_hmac_block_size) {
                uchar_t digested_key[SHA256_DIGEST_LENGTH];

                /*
                 * Hash the passed-in key to get a smaller key.
                 * The inner context is used since it hasn't been
                 * initialized yet.
                 */
                PROV_SHA2_DIGEST_KEY(mechanism->cm_type / 3,
                    &sha2_hmac_ctx_tmpl->hc_icontext,
                    key->ck_data, keylen_in_bytes, digested_key);
                sha2_mac_init_ctx(sha2_hmac_ctx_tmpl, digested_key,
                    sha_digest_len);
        } else {
                sha2_mac_init_ctx(sha2_hmac_ctx_tmpl, key->ck_data,
                    keylen_in_bytes);
        }

        *ctx_template = (crypto_spi_ctx_template_t)sha2_hmac_ctx_tmpl;
        *ctx_template_size = sizeof (sha2_hmac_ctx_t);

        return (CRYPTO_SUCCESS);
}

static int
sha2_free_context(crypto_ctx_t *ctx)
{
        uint_t ctx_len;

        if (ctx->cc_provider_private == NULL)
                return (CRYPTO_SUCCESS);

        /*
         * We have to free either SHA2 or SHA2-HMAC contexts, which
         * have different lengths.
         *
         * Note: Below is dependent on the mechanism ordering.
         */

        if (PROV_SHA2_CTX(ctx)->sc_mech_type % 3 == 0)
                ctx_len = sizeof (sha2_ctx_t);
        else
                ctx_len = sizeof (sha2_hmac_ctx_t);

        bzero(ctx->cc_provider_private, ctx_len);
        kmem_free(ctx->cc_provider_private, ctx_len);
        ctx->cc_provider_private = NULL;

        return (CRYPTO_SUCCESS);
}