crypto/md5/md5.c

	md5.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (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 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * Cleaned-up and optimized version of MD5, based on the reference
 * implementation provided in RFC 1321.  See RSA Copyright information
 * below.
 *
 * NOTE:  All compiler data was gathered with SC4.2, and verified with SC5.x,
 *    as used to build Solaris 2.7.  Hopefully the compiler behavior won't
 *    change for the worse in subsequent Solaris builds.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

/*
 * MD5C.C - RSA Data Security, Inc., MD5 message-digest algorithm
 */

/*
 * Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All
 * rights reserved.
 *
 * License to copy and use this software is granted provided that it
 * is identified as the "RSA Data Security, Inc. MD5 Message-Digest
 * Algorithm" in all material mentioning or referencing this software
 * or this function.
 *
 * License is also granted to make and use derivative works provided
 * that such works are identified as "derived from the RSA Data
 * Security, Inc. MD5 Message-Digest Algorithm" in all material
 * mentioning or referencing the derived work.
 *
 * RSA Data Security, Inc. makes no representations concerning either
 * the merchantability of this software or the suitability of this
 * software for any particular purpose. It is provided "as is"
 * without express or implied warranty of any kind.
 *
 * These notices must be retained in any copies of any part of this
 * documentation and/or software.
 */

#include <sys/types.h>
#include <sys/md5.h>
#include <sys/md5_consts.h> /* MD5_CONST() optimization */
#if !defined(_KERNEL) || defined(_BOOT)
#include <strings.h>
#endif /* !_KERNEL || _BOOT */

#if defined(_KERNEL) && !defined(_BOOT)

/*
 * In kernel module, the md5 module is created with two modlinkages:
 * - a modlmisc that allows consumers to directly call the entry points
 *   MD5Init, MD5Update, and MD5Final.
 * - a modlcrypto that allows the module to register with the Kernel
 *   Cryptographic Framework (KCF) as a software provider for the MD5
 *   mechanisms.
 */

#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>

extern struct mod_ops mod_miscops;
extern struct mod_ops mod_cryptoops;

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

static struct modlmisc modlmisc = {
    &mod_miscops,
    "MD5 Message-Digest Algorithm"
};

static struct modlcrypto modlcrypto = {
    &mod_cryptoops,
    "MD5 Kernel SW Provider %I%"
};

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

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

typedef enum md5_mech_type {
    MD5_MECH_INFO_TYPE,     /* SUN_CKM_MD5 */
    MD5_HMAC_MECH_INFO_TYPE,    /* SUN_CKM_MD5_HMAC */
    MD5_HMAC_GEN_MECH_INFO_TYPE /* SUN_CKM_MD5_HMAC_GENERAL */
} md5_mech_type_t;

#define MD5_DIGEST_LENGTH   16  /* MD5 digest length in bytes */
#define MD5_HMAC_BLOCK_SIZE 64  /* MD5 block size */
#define MD5_HMAC_MIN_KEY_LEN    8   /* MD5-HMAC min key length in bits */
#define MD5_HMAC_MAX_KEY_LEN    INT_MAX /* MD5-HMAC max key length in bits */
#define MD5_HMAC_INTS_PER_BLOCK (MD5_HMAC_BLOCK_SIZE/sizeof (uint32_t))

/*
 * Context for MD5 mechanism.
 */
typedef struct md5_ctx {
    md5_mech_type_t     mc_mech_type;   /* type of context */
    MD5_CTX         mc_md5_ctx; /* MD5 context */
} md5_ctx_t;

/*
 * Context for MD5-HMAC and MD5-HMAC-GENERAL mechanisms.
 */
typedef struct md5_hmac_ctx {
    md5_mech_type_t     hc_mech_type;   /* type of context */
    uint32_t        hc_digest_len;  /* digest len in bytes */
    MD5_CTX         hc_icontext;    /* inner MD5 context */
    MD5_CTX         hc_ocontext;    /* outer MD5 context */
} md5_hmac_ctx_t;

/*
 * Macros to access the MD5 or MD5-HMAC contexts from a context passed
 * by KCF to one of the entry points.
 */

#define PROV_MD5_CTX(ctx)   ((md5_ctx_t *)(ctx)->cc_provider_private)
#define PROV_MD5_HMAC_CTX(ctx)  ((md5_hmac_ctx_t *)(ctx)->cc_provider_private)
/* to extract the digest length passed as mechanism parameter */

#define PROV_MD5_GET_DIGEST_LEN(m, len) {               \
    if (IS_P2ALIGNED((m)->cm_param, sizeof (ulong_t)))      \
        (len) = (uint32_t)*((ulong_t *)mechanism->cm_param);    \
    else {                              \
        ulong_t tmp_ulong;                  \
        bcopy((m)->cm_param, &tmp_ulong, sizeof (ulong_t)); \
        (len) = (uint32_t)tmp_ulong;                \
    }                               \
}

#define PROV_MD5_DIGEST_KEY(ctx, key, len, digest) {    \
    MD5Init(ctx);                   \
    MD5Update(ctx, key, len);           \
    MD5Final(digest, ctx);              \
}

/*
 * Mechanism info structure passed to KCF during registration.
 */
static crypto_mech_info_t md5_mech_info_tab[] = {
    /* MD5 */
    {SUN_CKM_MD5, MD5_MECH_INFO_TYPE,
        CRYPTO_FG_DIGEST | CRYPTO_FG_DIGEST_ATOMIC,
        0, 0, CRYPTO_KEYSIZE_UNIT_IN_BITS},
    /* MD5-HMAC */
    {SUN_CKM_MD5_HMAC, MD5_HMAC_MECH_INFO_TYPE,
        CRYPTO_FG_MAC | CRYPTO_FG_MAC_ATOMIC,
        MD5_HMAC_MIN_KEY_LEN, MD5_HMAC_MAX_KEY_LEN,
        CRYPTO_KEYSIZE_UNIT_IN_BITS},
    /* MD5-HMAC GENERAL */
    {SUN_CKM_MD5_HMAC_GENERAL, MD5_HMAC_GEN_MECH_INFO_TYPE,
        CRYPTO_FG_MAC | CRYPTO_FG_MAC_ATOMIC,
        MD5_HMAC_MIN_KEY_LEN, MD5_HMAC_MAX_KEY_LEN,
        CRYPTO_KEYSIZE_UNIT_IN_BITS}
};

static void md5_provider_status(crypto_provider_handle_t, uint_t *);

static crypto_control_ops_t md5_control_ops = {
    md5_provider_status
};

static int md5_digest_init(crypto_ctx_t *, crypto_mechanism_t *,
    crypto_req_handle_t);
static int md5_digest(crypto_ctx_t *, crypto_data_t *, crypto_data_t *,
    crypto_req_handle_t);
static int md5_digest_update(crypto_ctx_t *, crypto_data_t *,
    crypto_req_handle_t);
static int md5_digest_final(crypto_ctx_t *, crypto_data_t *,
    crypto_req_handle_t);
static int md5_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 md5_digest_ops = {
    md5_digest_init,
    md5_digest,
    md5_digest_update,
    NULL,
    md5_digest_final,
    md5_digest_atomic
};

static int md5_mac_init(crypto_ctx_t *, crypto_mechanism_t *, crypto_key_t *,
    crypto_spi_ctx_template_t, crypto_req_handle_t);
static int md5_mac_update(crypto_ctx_t *, crypto_data_t *, crypto_req_handle_t);
static int md5_mac_final(crypto_ctx_t *, crypto_data_t *, crypto_req_handle_t);
static int md5_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 md5_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 md5_mac_ops = {
    md5_mac_init,
    NULL,
    md5_mac_update,
    md5_mac_final,
    md5_mac_atomic,
    md5_mac_verify_atomic
};

static int md5_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 md5_free_context(crypto_ctx_t *);

static crypto_ctx_ops_t md5_ctx_ops = {
    md5_create_ctx_template,
    md5_free_context
};

static crypto_ops_t md5_crypto_ops = {
    &md5_control_ops,
    &md5_digest_ops,
    NULL,
    &md5_mac_ops,
    NULL,
    NULL,
    NULL,
    NULL,
    NULL,
    NULL,
    NULL,
    NULL,
    NULL,
    &md5_ctx_ops
};

static crypto_provider_info_t md5_prov_info = {
    CRYPTO_SPI_VERSION_1,
    "MD5 Software Provider",
    CRYPTO_SW_PROVIDER,
    {&modlinkage},
    NULL,
    &md5_crypto_ops,
    sizeof (md5_mech_info_tab)/sizeof (crypto_mech_info_t),
    md5_mech_info_tab
};

static crypto_kcf_provider_handle_t md5_prov_handle = NULL;

int
_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/md5 should still be available.
     */
    if ((ret = crypto_register_provider(&md5_prov_info,
        &md5_prov_handle)) != CRYPTO_SUCCESS)
        cmn_err(CE_WARN, "md5 _init: "
            "crypto_register_provider() failed (0x%x)", ret);

    return (0);
}

int
_fini(void)
{
    int ret;

    /*
     * Unregister from KCF if previous registration succeeded.
     */
    if (md5_prov_handle != NULL) {
        if ((ret = crypto_unregister_provider(md5_prov_handle)) !=
            CRYPTO_SUCCESS) {
            cmn_err(CE_WARN, "md5 _fini: "
                "crypto_unregister_provider() failed (0x%x)", ret);
            return (EBUSY);
        }
        md5_prov_handle = NULL;
    }

    return (mod_remove(&modlinkage));
}

int
_info(struct modinfo *modinfop)
{
    return (mod_info(&modlinkage, modinfop));
}
#endif  /* _KERNEL && !_BOOT */

static void Encode(uint8_t *, uint32_t *, size_t);
static void MD5Transform(uint32_t, uint32_t, uint32_t, uint32_t, MD5_CTX *,
    const uint8_t [64]);

static uint8_t PADDING[64] = { 0x80, /* all zeros */ };

/*
 * F, G, H and I are the basic MD5 functions.
 */
#define F(b, c, d)  (((b) & (c)) | ((~b) & (d)))
#define G(b, c, d)  (((b) & (d)) | ((c) & (~d)))
#define H(b, c, d)  ((b) ^ (c) ^ (d))
#define I(b, c, d)  ((c) ^ ((b) | (~d)))

/*
 * ROTATE_LEFT rotates x left n bits.
 */
#define ROTATE_LEFT(x, n)   \
    (((x) << (n)) | ((x) >> ((sizeof (x) << 3) - (n))))

/*
 * FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
 * Rotation is separate from addition to prevent recomputation.
 */

#define FF(a, b, c, d, x, s, ac) { \
    (a) += F((b), (c), (d)) + (x) + (uint32_t)(ac); \
    (a) = ROTATE_LEFT((a), (s)); \
    (a) += (b); \
    }

#define GG(a, b, c, d, x, s, ac) { \
    (a) += G((b), (c), (d)) + (x) + (uint32_t)(ac); \
    (a) = ROTATE_LEFT((a), (s)); \
    (a) += (b); \
    }

#define HH(a, b, c, d, x, s, ac) { \
    (a) += H((b), (c), (d)) + (x) + (uint32_t)(ac); \
    (a) = ROTATE_LEFT((a), (s)); \
    (a) += (b); \
    }

#define II(a, b, c, d, x, s, ac) { \
    (a) += I((b), (c), (d)) + (x) + (uint32_t)(ac); \
    (a) = ROTATE_LEFT((a), (s)); \
    (a) += (b); \
    }

/*
 * Loading 32-bit constants on a RISC is expensive since it involves both a
 * `sethi' and an `or'.  thus, we instead have the compiler generate `ld's to
 * load the constants from an array called `md5_consts'.  however, on intel
 * (and other CISC processors), it is cheaper to load the constant
 * directly.  thus, the c code in MD5Transform() uses the macro MD5_CONST()
 * which either expands to a constant or an array reference, depending on the
 * architecture the code is being compiled for.
 *
 * Right now, i386 and amd64 are the CISC exceptions.
 * If we get another CISC ISA, we'll have to change the ifdef.
 */

#if defined(__i386) || defined(__amd64)

#define MD5_CONST(x)        (MD5_CONST_ ## x)

#else
/*
 * sparc/RISC optimization:
 *
 * while it is somewhat counter-intuitive, on sparc (and presumably other RISC
 * machines), it is more efficient to place all the constants used in this
 * function in an array and load the values out of the array than to manually
 * load the constants.  this is because setting a register to a 32-bit value
 * takes two ops in most cases: a `sethi' and an `or', but loading a 32-bit
 * value from memory only takes one `ld' (or `lduw' on v9).  while this
 * increases memory usage, the compiler can find enough other things to do
 * while waiting to keep the pipeline does not stall.  additionally, it is
 * likely that many of these constants are cached so that later accesses do
 * not even go out to the bus.
 *
 * this array is declared `static' to keep the compiler from having to
 * bcopy() this array onto the stack frame of MD5Transform() each time it is
 * called -- which is unacceptably expensive.
 *
 * the `const' is to ensure that callers are good citizens and do not try to
 * munge the array.  since these routines are going to be called from inside
 * multithreaded kernelland, this is a good safety check. -- `constants' will
 * end up in .rodata.
 *
 * unfortunately, loading from an array in this manner hurts performance under
 * intel (and presumably other CISC machines).  so, there is a macro,
 * MD5_CONST(), used in MD5Transform(), that either expands to a reference to
 * this array, or to the actual constant, depending on what platform this code
 * is compiled for.
 */

static const uint32_t md5_consts[] = {
    MD5_CONST_0,    MD5_CONST_1,    MD5_CONST_2,    MD5_CONST_3,
    MD5_CONST_4,    MD5_CONST_5,    MD5_CONST_6,    MD5_CONST_7,
    MD5_CONST_8,    MD5_CONST_9,    MD5_CONST_10,   MD5_CONST_11,
    MD5_CONST_12,   MD5_CONST_13,   MD5_CONST_14,   MD5_CONST_15,
    MD5_CONST_16,   MD5_CONST_17,   MD5_CONST_18,   MD5_CONST_19,
    MD5_CONST_20,   MD5_CONST_21,   MD5_CONST_22,   MD5_CONST_23,
    MD5_CONST_24,   MD5_CONST_25,   MD5_CONST_26,   MD5_CONST_27,
    MD5_CONST_28,   MD5_CONST_29,   MD5_CONST_30,   MD5_CONST_31,
    MD5_CONST_32,   MD5_CONST_33,   MD5_CONST_34,   MD5_CONST_35,
    MD5_CONST_36,   MD5_CONST_37,   MD5_CONST_38,   MD5_CONST_39,
    MD5_CONST_40,   MD5_CONST_41,   MD5_CONST_42,   MD5_CONST_43,
    MD5_CONST_44,   MD5_CONST_45,   MD5_CONST_46,   MD5_CONST_47,
    MD5_CONST_48,   MD5_CONST_49,   MD5_CONST_50,   MD5_CONST_51,
    MD5_CONST_52,   MD5_CONST_53,   MD5_CONST_54,   MD5_CONST_55,
    MD5_CONST_56,   MD5_CONST_57,   MD5_CONST_58,   MD5_CONST_59,
    MD5_CONST_60,   MD5_CONST_61,   MD5_CONST_62,   MD5_CONST_63
};

#define MD5_CONST(x)        (md5_consts[x])

#endif

/*
 * MD5Init()
 *
 * purpose: initializes the md5 context and begins and md5 digest operation
 *   input: MD5_CTX *   : the context to initialize.
 *  output: void
 */

void
MD5Init(MD5_CTX *ctx)
{
    ctx->count[0] = ctx->count[1] = 0;

    /* load magic initialization constants */
    ctx->state[0] = MD5_INIT_CONST_1;
    ctx->state[1] = MD5_INIT_CONST_2;
    ctx->state[2] = MD5_INIT_CONST_3;
    ctx->state[3] = MD5_INIT_CONST_4;
}

/*
 * MD5Update()
 *
 * purpose: continues an md5 digest operation, using the message block
 *          to update the context.
 *   input: MD5_CTX *   : the context to update
 *          uint8_t *   : the message block
 *          uint32_t    : the length of the message block in bytes
 *  output: void
 *
 * MD5 crunches in 64-byte blocks.  All numeric constants here are related to
 * that property of MD5.
 */

void
MD5Update(MD5_CTX *ctx, const void *inpp, unsigned int input_len)
{
    uint32_t        i, buf_index, buf_len;
    const unsigned char     *input = (const unsigned char *)inpp;

    /* compute (number of bytes computed so far) mod 64 */
    buf_index = (ctx->count[0] >> 3) & 0x3F;

    /* update number of bits hashed into this MD5 computation so far */
    if ((ctx->count[0] += (input_len << 3)) < (input_len << 3))
        ctx->count[1]++;
    ctx->count[1] += (input_len >> 29);

    buf_len = 64 - buf_index;

    /* transform as many times as possible */
    i = 0;
    if (input_len >= buf_len) {

        /*
         * general optimization:
         *
         * only do initial bcopy() and MD5Transform() if
         * buf_index != 0.  if buf_index == 0, we're just
         * wasting our time doing the bcopy() since there
         * wasn't any data left over from a previous call to
         * MD5Update().
         */

        if (buf_index) {
            bcopy(input, &ctx->buf_un.buf8[buf_index], buf_len);

            MD5Transform(ctx->state[0], ctx->state[1],
                ctx->state[2], ctx->state[3], ctx,
                ctx->buf_un.buf8);

            i = buf_len;
        }

        for (; i + 63 < input_len; i += 64)
            MD5Transform(ctx->state[0], ctx->state[1],
                ctx->state[2], ctx->state[3], ctx, &input[i]);

        /*
         * general optimization:
         *
         * if i and input_len are the same, return now instead
         * of calling bcopy(), since the bcopy() in this
         * case will be an expensive nop.
         */

        if (input_len == i)
            return;

        buf_index = 0;
    }

    /* buffer remaining input */
    bcopy(&input[i], &ctx->buf_un.buf8[buf_index], input_len - i);
}

/*
 * MD5Final()
 *
 * purpose: ends an md5 digest operation, finalizing the message digest and
 *          zeroing the context.
 *   input: uint8_t *   : a buffer to store the digest in
 *          MD5_CTX *   : the context to finalize, save, and zero
 *  output: void
 */

void
MD5Final(unsigned char *digest, MD5_CTX *ctx)
{
    uint8_t     bitcount_le[sizeof (ctx->count)];
    uint32_t    index = (ctx->count[0] >> 3) & 0x3f;

    /* store bit count, little endian */
    Encode(bitcount_le, ctx->count, sizeof (bitcount_le));

    /* pad out to 56 mod 64 */
    MD5Update(ctx, PADDING, ((index < 56) ? 56 : 120) - index);

    /* append length (before padding) */
    MD5Update(ctx, bitcount_le, sizeof (bitcount_le));

    /* store state in digest */
    Encode(digest, ctx->state, sizeof (ctx->state));
}

#ifndef _KERNEL

void
md5_calc(unsigned char *output, unsigned char *input, unsigned int inlen)
{
    MD5_CTX context;

    MD5Init(&context);
    MD5Update(&context, input, inlen);
    MD5Final(output, &context);
}

#endif  /* !_KERNEL */

/*
 * Little-endian optimization:  I don't need to do any weirdness.   On
 * some little-endian boxen, I'll have to do alignment checks, but I can do
 * that below.
 */

#ifdef _LITTLE_ENDIAN

#if !defined(__i386) && !defined(__amd64)
/*
 * i386 and amd64 don't require aligned 4-byte loads.  The symbol
 * _MD5_CHECK_ALIGNMENT indicates below whether the MD5Transform function
 * requires alignment checking.
 */
#define _MD5_CHECK_ALIGNMENT
#endif /* !__i386 && !__amd64 */

#define LOAD_LITTLE_32(addr)    (*(uint32_t *)(addr))

/*
 * sparc v9/v8plus optimization:
 *
 * on the sparc v9/v8plus, we can load data little endian.  however, since
 * the compiler doesn't have direct support for little endian, we
 * link to an assembly-language routine `load_little_32' to do
 * the magic.  note that special care must be taken to ensure the
 * address is 32-bit aligned -- in the interest of speed, we don't
 * check to make sure, since careful programming can guarantee this
 * for us.
 */

#elif   defined(sun4u)

/* Define alignment check because we can 4-byte load as little endian. */
#define _MD5_CHECK_ALIGNMENT
extern  uint32_t load_little_32(uint32_t *);
#define LOAD_LITTLE_32(addr)    load_little_32((uint32_t *)(addr))

/* Placate lint */
#if defined(__lint)
uint32_t
load_little_32(uint32_t *addr)
{
    return (*addr);
}
#endif

#else   /* big endian -- will work on little endian, but slowly */

/* Since we do byte operations, we don't have to check for alignment. */
#define LOAD_LITTLE_32(addr)    \
    ((addr)[0] | ((addr)[1] << 8) | ((addr)[2] << 16) | ((addr)[3] << 24))
#endif

/*
 * sparc register window optimization:
 *
 * `a', `b', `c', and `d' are passed into MD5Transform explicitly
 * since it increases the number of registers available to the
 * compiler.  under this scheme, these variables can be held in
 * %i0 - %i3, which leaves more local and out registers available.
 */

/*
 * MD5Transform()
 *
 * purpose: md5 transformation -- updates the digest based on `block'
 *   input: uint32_t    : bytes  1 -  4 of the digest
 *          uint32_t    : bytes  5 -  8 of the digest
 *          uint32_t    : bytes  9 - 12 of the digest
 *          uint32_t    : bytes 12 - 16 of the digest
 *          MD5_CTX *   : the context to update
 *          uint8_t [64]: the block to use to update the digest
 *  output: void
 */

static void
MD5Transform(uint32_t a, uint32_t b, uint32_t c, uint32_t d,
    MD5_CTX *ctx, const uint8_t block[64])
{
    /*
     * general optimization:
     *
     * use individual integers instead of using an array.  this is a
     * win, although the amount it wins by seems to vary quite a bit.
     */

    register uint32_t   x_0, x_1, x_2,  x_3,  x_4,  x_5,  x_6,  x_7;
    register uint32_t   x_8, x_9, x_10, x_11, x_12, x_13, x_14, x_15;

    /*
     * general optimization:
     *
     * the compiler (at least SC4.2/5.x) generates better code if
     * variable use is localized.  in this case, swapping the integers in
     * this order allows `x_0 'to be swapped nearest to its first use in
     * FF(), and likewise for `x_1' and up.  note that the compiler
     * prefers this to doing each swap right before the FF() that
     * uses it.
     */

    /*
     * sparc v9/v8plus optimization:
     *
     * if `block' is already aligned on a 4-byte boundary, use the
     * optimized load_little_32() directly.  otherwise, bcopy()
     * into a buffer that *is* aligned on a 4-byte boundary and
     * then do the load_little_32() on that buffer.  benchmarks
     * have shown that using the bcopy() is better than loading
     * the bytes individually and doing the endian-swap by hand.
     *
     * even though it's quite tempting to assign to do:
     *
     * blk = bcopy(blk, ctx->buf_un.buf32, sizeof (ctx->buf_un.buf32));
     *
     * and only have one set of LOAD_LITTLE_32()'s, the compiler (at least
     * SC4.2/5.x) *does not* like that, so please resist the urge.
     */

#ifdef _MD5_CHECK_ALIGNMENT
    if ((uintptr_t)block & 0x3) {       /* not 4-byte aligned? */
        bcopy(block, ctx->buf_un.buf32, sizeof (ctx->buf_un.buf32));
        x_15 = LOAD_LITTLE_32(ctx->buf_un.buf32 + 15);
        x_14 = LOAD_LITTLE_32(ctx->buf_un.buf32 + 14);
        x_13 = LOAD_LITTLE_32(ctx->buf_un.buf32 + 13);
        x_12 = LOAD_LITTLE_32(ctx->buf_un.buf32 + 12);
        x_11 = LOAD_LITTLE_32(ctx->buf_un.buf32 + 11);
        x_10 = LOAD_LITTLE_32(ctx->buf_un.buf32 + 10);
        x_9  = LOAD_LITTLE_32(ctx->buf_un.buf32 +  9);
        x_8  = LOAD_LITTLE_32(ctx->buf_un.buf32 +  8);
        x_7  = LOAD_LITTLE_32(ctx->buf_un.buf32 +  7);
        x_6  = LOAD_LITTLE_32(ctx->buf_un.buf32 +  6);
        x_5  = LOAD_LITTLE_32(ctx->buf_un.buf32 +  5);
        x_4  = LOAD_LITTLE_32(ctx->buf_un.buf32 +  4);
        x_3  = LOAD_LITTLE_32(ctx->buf_un.buf32 +  3);
        x_2  = LOAD_LITTLE_32(ctx->buf_un.buf32 +  2);
        x_1  = LOAD_LITTLE_32(ctx->buf_un.buf32 +  1);
        x_0  = LOAD_LITTLE_32(ctx->buf_un.buf32 +  0);
    } else
#endif
    {
        x_15 = LOAD_LITTLE_32(block + 60);
        x_14 = LOAD_LITTLE_32(block + 56);
        x_13 = LOAD_LITTLE_32(block + 52);
        x_12 = LOAD_LITTLE_32(block + 48);
        x_11 = LOAD_LITTLE_32(block + 44);
        x_10 = LOAD_LITTLE_32(block + 40);
        x_9  = LOAD_LITTLE_32(block + 36);
        x_8  = LOAD_LITTLE_32(block + 32);
        x_7  = LOAD_LITTLE_32(block + 28);
        x_6  = LOAD_LITTLE_32(block + 24);
        x_5  = LOAD_LITTLE_32(block + 20);
        x_4  = LOAD_LITTLE_32(block + 16);
        x_3  = LOAD_LITTLE_32(block + 12);
        x_2  = LOAD_LITTLE_32(block +  8);
        x_1  = LOAD_LITTLE_32(block +  4);
        x_0  = LOAD_LITTLE_32(block +  0);
    }

    /* round 1 */
    FF(a, b, c, d,  x_0, MD5_SHIFT_11, MD5_CONST(0));  /* 1 */
    FF(d, a, b, c,  x_1, MD5_SHIFT_12, MD5_CONST(1));  /* 2 */
    FF(c, d, a, b,  x_2, MD5_SHIFT_13, MD5_CONST(2));  /* 3 */
    FF(b, c, d, a,  x_3, MD5_SHIFT_14, MD5_CONST(3));  /* 4 */
    FF(a, b, c, d,  x_4, MD5_SHIFT_11, MD5_CONST(4));  /* 5 */
    FF(d, a, b, c,  x_5, MD5_SHIFT_12, MD5_CONST(5));  /* 6 */
    FF(c, d, a, b,  x_6, MD5_SHIFT_13, MD5_CONST(6));  /* 7 */
    FF(b, c, d, a,  x_7, MD5_SHIFT_14, MD5_CONST(7));  /* 8 */
    FF(a, b, c, d,  x_8, MD5_SHIFT_11, MD5_CONST(8));  /* 9 */
    FF(d, a, b, c,  x_9, MD5_SHIFT_12, MD5_CONST(9));  /* 10 */
    FF(c, d, a, b, x_10, MD5_SHIFT_13, MD5_CONST(10)); /* 11 */
    FF(b, c, d, a, x_11, MD5_SHIFT_14, MD5_CONST(11)); /* 12 */
    FF(a, b, c, d, x_12, MD5_SHIFT_11, MD5_CONST(12)); /* 13 */
    FF(d, a, b, c, x_13, MD5_SHIFT_12, MD5_CONST(13)); /* 14 */
    FF(c, d, a, b, x_14, MD5_SHIFT_13, MD5_CONST(14)); /* 15 */
    FF(b, c, d, a, x_15, MD5_SHIFT_14, MD5_CONST(15)); /* 16 */

    /* round 2 */
    GG(a, b, c, d,  x_1, MD5_SHIFT_21, MD5_CONST(16)); /* 17 */
    GG(d, a, b, c,  x_6, MD5_SHIFT_22, MD5_CONST(17)); /* 18 */
    GG(c, d, a, b, x_11, MD5_SHIFT_23, MD5_CONST(18)); /* 19 */
    GG(b, c, d, a,  x_0, MD5_SHIFT_24, MD5_CONST(19)); /* 20 */
    GG(a, b, c, d,  x_5, MD5_SHIFT_21, MD5_CONST(20)); /* 21 */
    GG(d, a, b, c, x_10, MD5_SHIFT_22, MD5_CONST(21)); /* 22 */
    GG(c, d, a, b, x_15, MD5_SHIFT_23, MD5_CONST(22)); /* 23 */
    GG(b, c, d, a,  x_4, MD5_SHIFT_24, MD5_CONST(23)); /* 24 */
    GG(a, b, c, d,  x_9, MD5_SHIFT_21, MD5_CONST(24)); /* 25 */
    GG(d, a, b, c, x_14, MD5_SHIFT_22, MD5_CONST(25)); /* 26 */
    GG(c, d, a, b,  x_3, MD5_SHIFT_23, MD5_CONST(26)); /* 27 */
    GG(b, c, d, a,  x_8, MD5_SHIFT_24, MD5_CONST(27)); /* 28 */
    GG(a, b, c, d, x_13, MD5_SHIFT_21, MD5_CONST(28)); /* 29 */
    GG(d, a, b, c,  x_2, MD5_SHIFT_22, MD5_CONST(29)); /* 30 */
    GG(c, d, a, b,  x_7, MD5_SHIFT_23, MD5_CONST(30)); /* 31 */
    GG(b, c, d, a, x_12, MD5_SHIFT_24, MD5_CONST(31)); /* 32 */

    /* round 3 */
    HH(a, b, c, d,  x_5, MD5_SHIFT_31, MD5_CONST(32)); /* 33 */
    HH(d, a, b, c,  x_8, MD5_SHIFT_32, MD5_CONST(33)); /* 34 */
    HH(c, d, a, b, x_11, MD5_SHIFT_33, MD5_CONST(34)); /* 35 */
    HH(b, c, d, a, x_14, MD5_SHIFT_34, MD5_CONST(35)); /* 36 */
    HH(a, b, c, d,  x_1, MD5_SHIFT_31, MD5_CONST(36)); /* 37 */
    HH(d, a, b, c,  x_4, MD5_SHIFT_32, MD5_CONST(37)); /* 38 */
    HH(c, d, a, b,  x_7, MD5_SHIFT_33, MD5_CONST(38)); /* 39 */
    HH(b, c, d, a, x_10, MD5_SHIFT_34, MD5_CONST(39)); /* 40 */
    HH(a, b, c, d, x_13, MD5_SHIFT_31, MD5_CONST(40)); /* 41 */
    HH(d, a, b, c,  x_0, MD5_SHIFT_32, MD5_CONST(41)); /* 42 */
    HH(c, d, a, b,  x_3, MD5_SHIFT_33, MD5_CONST(42)); /* 43 */
    HH(b, c, d, a,  x_6, MD5_SHIFT_34, MD5_CONST(43)); /* 44 */
    HH(a, b, c, d,  x_9, MD5_SHIFT_31, MD5_CONST(44)); /* 45 */
    HH(d, a, b, c, x_12, MD5_SHIFT_32, MD5_CONST(45)); /* 46 */
    HH(c, d, a, b, x_15, MD5_SHIFT_33, MD5_CONST(46)); /* 47 */
    HH(b, c, d, a,  x_2, MD5_SHIFT_34, MD5_CONST(47)); /* 48 */

    /* round 4 */
    II(a, b, c, d,  x_0, MD5_SHIFT_41, MD5_CONST(48)); /* 49 */
    II(d, a, b, c,  x_7, MD5_SHIFT_42, MD5_CONST(49)); /* 50 */
    II(c, d, a, b, x_14, MD5_SHIFT_43, MD5_CONST(50)); /* 51 */
    II(b, c, d, a,  x_5, MD5_SHIFT_44, MD5_CONST(51)); /* 52 */
    II(a, b, c, d, x_12, MD5_SHIFT_41, MD5_CONST(52)); /* 53 */
    II(d, a, b, c,  x_3, MD5_SHIFT_42, MD5_CONST(53)); /* 54 */
    II(c, d, a, b, x_10, MD5_SHIFT_43, MD5_CONST(54)); /* 55 */
    II(b, c, d, a,  x_1, MD5_SHIFT_44, MD5_CONST(55)); /* 56 */
    II(a, b, c, d,  x_8, MD5_SHIFT_41, MD5_CONST(56)); /* 57 */
    II(d, a, b, c, x_15, MD5_SHIFT_42, MD5_CONST(57)); /* 58 */
    II(c, d, a, b,  x_6, MD5_SHIFT_43, MD5_CONST(58)); /* 59 */
    II(b, c, d, a, x_13, MD5_SHIFT_44, MD5_CONST(59)); /* 60 */
    II(a, b, c, d,  x_4, MD5_SHIFT_41, MD5_CONST(60)); /* 61 */
    II(d, a, b, c, x_11, MD5_SHIFT_42, MD5_CONST(61)); /* 62 */
    II(c, d, a, b,  x_2, MD5_SHIFT_43, MD5_CONST(62)); /* 63 */
    II(b, c, d, a,  x_9, MD5_SHIFT_44, MD5_CONST(63)); /* 64 */

    ctx->state[0] += a;
    ctx->state[1] += b;
    ctx->state[2] += c;
    ctx->state[3] += d;

    /*
     * zeroize sensitive information -- compiler will optimize
     * this out if everything is kept in registers
     */

    x_0 = x_1  = x_2  = x_3  = x_4  = x_5  = x_6  = x_7 = x_8 = 0;
    x_9 = x_10 = x_11 = x_12 = x_13 = x_14 = x_15 = 0;
}

/*
 * devpro compiler optimization:
 *
 * the compiler can generate better code if it knows that `input' and
 * `output' do not point to the same source.  there is no portable
 * way to tell the compiler this, but the devpro compiler recognizes the
 * `_Restrict' keyword to indicate this condition.  use it if possible.
 */

#if defined(__RESTRICT) && !defined(__GNUC__)
#define restrict    _Restrict
#else
#define restrict    /* nothing */
#endif

/*
 * Encode()
 *
 * purpose: to convert a list of numbers from big endian to little endian
 *   input: uint8_t *   : place to store the converted little endian numbers
 *      uint32_t *  : place to get numbers to convert from
 *          size_t  : the length of the input in bytes
 *  output: void
 */

static void
Encode(uint8_t *restrict output, uint32_t *restrict input, size_t input_len)
{
    size_t      i, j;

    for (i = 0, j = 0; j < input_len; i++, j += sizeof (uint32_t)) {

#ifdef _LITTLE_ENDIAN

#ifdef _MD5_CHECK_ALIGNMENT
        if ((uintptr_t)output & 0x3)    /* Not 4-byte aligned */
            bcopy(input + i, output + j, 4);
        else *(uint32_t *)(output + j) = input[i];
#else
        *(uint32_t *)(output + j) = input[i];
#endif /* _MD5_CHECK_ALIGNMENT */

#else   /* big endian -- will work on little endian, but slowly */

        output[j] = input[i] & 0xff;
        output[j + 1] = (input[i] >> 8)  & 0xff;
        output[j + 2] = (input[i] >> 16) & 0xff;
        output[j + 3] = (input[i] >> 24) & 0xff;
#endif
    }
}

#if defined(_KERNEL) && !defined(_BOOT)

/*
 * KCF software provider control entry points.
 */
/* ARGSUSED */
static void
md5_provider_status(crypto_provider_handle_t provider, uint_t *status)
{
    *status = CRYPTO_PROVIDER_READY;
}

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

static int
md5_digest_init(crypto_ctx_t *ctx, crypto_mechanism_t *mechanism,
    crypto_req_handle_t req)
{
    if (mechanism->cm_type != MD5_MECH_INFO_TYPE)
        return (CRYPTO_MECHANISM_INVALID);

    /*
     * Allocate and initialize MD5 context.
     */
    ctx->cc_provider_private = kmem_alloc(sizeof (md5_ctx_t),
        crypto_kmflag(req));
    if (ctx->cc_provider_private == NULL)
        return (CRYPTO_HOST_MEMORY);

    PROV_MD5_CTX(ctx)->mc_mech_type = MD5_MECH_INFO_TYPE;
    MD5Init(&PROV_MD5_CTX(ctx)->mc_md5_ctx);

    return (CRYPTO_SUCCESS);
}

/*
 * Helper MD5 digest update function for uio data.
 */
static int
md5_digest_update_uio(MD5_CTX *md5_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);

        MD5Update(md5_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 MD5 digest final function for uio data.
 * digest_len is the length of the desired digest. If digest_len
 * is smaller than the default MD5 digest length, the caller
 * must pass a scratch buffer, digest_scratch, which must
 * be at least MD5_DIGEST_LENGTH bytes.
 */
static int
md5_digest_final_uio(MD5_CTX *md5_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 MD5 digest will fit in the current
         * iovec.
         */
        if (digest_len != MD5_DIGEST_LENGTH) {
            /*
             * The caller requested a short digest. Digest
             * into a scratch buffer and return to
             * the user only what was requested.
             */
            MD5Final(digest_scratch, md5_ctx);
            bcopy(digest_scratch, (uchar_t *)digest->
                cd_uio->uio_iov[vec_idx].iov_base + offset,
                digest_len);
        } else {
            MD5Final((uchar_t *)digest->
                cd_uio->uio_iov[vec_idx].iov_base + offset,
                md5_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[MD5_DIGEST_LENGTH];
        off_t scratch_offset = 0;
        size_t length = digest_len;
        size_t cur_len;

        MD5Final(digest_tmp, md5_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 MD5 digest update for mblk's.
 */
static int
md5_digest_update_mblk(MD5_CTX *md5_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);
        MD5Update(md5_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 MD5 digest final for mblk's.
 * digest_len is the length of the desired digest. If digest_len
 * is smaller than the default MD5 digest length, the caller
 * must pass a scratch buffer, digest_scratch, which must
 * be at least MD5_DIGEST_LENGTH bytes.
 */
static int
md5_digest_final_mblk(MD5_CTX *md5_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 MD5 digest will fit in the current mblk.
         * Do the MD5Final() in-place.
         */
        if (digest_len != MD5_DIGEST_LENGTH) {
            /*
             * The caller requested a short digest. Digest
             * into a scratch buffer and return to
             * the user only what was requested.
             */
            MD5Final(digest_scratch, md5_ctx);
            bcopy(digest_scratch, mp->b_rptr + offset, digest_len);
        } else {
            MD5Final(mp->b_rptr + offset, md5_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[MD5_DIGEST_LENGTH];
        off_t scratch_offset = 0;
        size_t length = digest_len;
        size_t cur_len;

        MD5Final(digest_tmp, md5_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
md5_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 < MD5_DIGEST_LENGTH)) {
        digest->cd_length = MD5_DIGEST_LENGTH;
        return (CRYPTO_BUFFER_TOO_SMALL);
    }

    /*
     * Do the MD5 update on the specified input data.
     */
    switch (data->cd_format) {
    case CRYPTO_DATA_RAW:
        MD5Update(&PROV_MD5_CTX(ctx)->mc_md5_ctx,
            data->cd_raw.iov_base + data->cd_offset,
            data->cd_length);
        break;
    case CRYPTO_DATA_UIO:
        ret = md5_digest_update_uio(&PROV_MD5_CTX(ctx)->mc_md5_ctx,
            data);
        break;
    case CRYPTO_DATA_MBLK:
        ret = md5_digest_update_mblk(&PROV_MD5_CTX(ctx)->mc_md5_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 (md5_ctx_t));
        ctx->cc_provider_private = NULL;
        digest->cd_length = 0;
        return (ret);
    }

    /*
     * Do an MD5 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:
        MD5Final((unsigned char *)digest->cd_raw.iov_base +
            digest->cd_offset, &PROV_MD5_CTX(ctx)->mc_md5_ctx);
        break;
    case CRYPTO_DATA_UIO:
        ret = md5_digest_final_uio(&PROV_MD5_CTX(ctx)->mc_md5_ctx,
            digest, MD5_DIGEST_LENGTH, NULL);
        break;
    case CRYPTO_DATA_MBLK:
        ret = md5_digest_final_mblk(&PROV_MD5_CTX(ctx)->mc_md5_ctx,
            digest, MD5_DIGEST_LENGTH, NULL);
        break;
    default:
        ret = CRYPTO_ARGUMENTS_BAD;
    }

    /* all done, free context and return */

    if (ret == CRYPTO_SUCCESS) {
        digest->cd_length = MD5_DIGEST_LENGTH;
    } else {
        digest->cd_length = 0;
    }

    kmem_free(ctx->cc_provider_private, sizeof (md5_ctx_t));
    ctx->cc_provider_private = NULL;
    return (ret);
}

/* ARGSUSED */
static int
md5_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 MD5 update on the specified input data.
     */
    switch (data->cd_format) {
    case CRYPTO_DATA_RAW:
        MD5Update(&PROV_MD5_CTX(ctx)->mc_md5_ctx,
            data->cd_raw.iov_base + data->cd_offset,
            data->cd_length);
        break;
    case CRYPTO_DATA_UIO:
        ret = md5_digest_update_uio(&PROV_MD5_CTX(ctx)->mc_md5_ctx,
            data);
        break;
    case CRYPTO_DATA_MBLK:
        ret = md5_digest_update_mblk(&PROV_MD5_CTX(ctx)->mc_md5_ctx,
            data);
        break;
    default:
        ret = CRYPTO_ARGUMENTS_BAD;
    }

    return (ret);
}

/* ARGSUSED */
static int
md5_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 < MD5_DIGEST_LENGTH)) {
        digest->cd_length = MD5_DIGEST_LENGTH;
        return (CRYPTO_BUFFER_TOO_SMALL);
    }

    /*
     * Do an MD5 final.
     */
    switch (digest->cd_format) {
    case CRYPTO_DATA_RAW:
        MD5Final((unsigned char *)digest->cd_raw.iov_base +
            digest->cd_offset, &PROV_MD5_CTX(ctx)->mc_md5_ctx);
        break;
    case CRYPTO_DATA_UIO:
        ret = md5_digest_final_uio(&PROV_MD5_CTX(ctx)->mc_md5_ctx,
            digest, MD5_DIGEST_LENGTH, NULL);
        break;
    case CRYPTO_DATA_MBLK:
        ret = md5_digest_final_mblk(&PROV_MD5_CTX(ctx)->mc_md5_ctx,
            digest, MD5_DIGEST_LENGTH, NULL);
        break;
    default:
        ret = CRYPTO_ARGUMENTS_BAD;
    }

    /* all done, free context and return */

    if (ret == CRYPTO_SUCCESS) {
        digest->cd_length = MD5_DIGEST_LENGTH;
    } else {
        digest->cd_length = 0;
    }

    kmem_free(ctx->cc_provider_private, sizeof (md5_ctx_t));
    ctx->cc_provider_private = NULL;

    return (ret);
}

/* ARGSUSED */
static int
md5_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;
    MD5_CTX md5_ctx;

    if (mechanism->cm_type != MD5_MECH_INFO_TYPE)
        return (CRYPTO_MECHANISM_INVALID);

    /*
     * Do the MD5 init.
     */
    MD5Init(&md5_ctx);

    /*
     * Do the MD5 update on the specified input data.
     */
    switch (data->cd_format) {
    case CRYPTO_DATA_RAW:
        MD5Update(&md5_ctx, data->cd_raw.iov_base + data->cd_offset,
            data->cd_length);
        break;
    case CRYPTO_DATA_UIO:
        ret = md5_digest_update_uio(&md5_ctx, data);
        break;
    case CRYPTO_DATA_MBLK:
        ret = md5_digest_update_mblk(&md5_ctx, data);
        break;
    default:
        ret = CRYPTO_ARGUMENTS_BAD;
    }

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

    /*
     * Do an MD5 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:
        MD5Final((unsigned char *)digest->cd_raw.iov_base +
            digest->cd_offset, &md5_ctx);
        break;
    case CRYPTO_DATA_UIO:
        ret = md5_digest_final_uio(&md5_ctx, digest,
            MD5_DIGEST_LENGTH, NULL);
        break;
    case CRYPTO_DATA_MBLK:
        ret = md5_digest_final_mblk(&md5_ctx, digest,
            MD5_DIGEST_LENGTH, NULL);
        break;
    default:
        ret = CRYPTO_ARGUMENTS_BAD;
    }

    if (ret == CRYPTO_SUCCESS) {
        digest->cd_length = MD5_DIGEST_LENGTH;
    } else {
        digest->cd_length = 0;
    }

    return (ret);
}

/*
 * KCF software provider mac entry points.
 *
 * MD5 HMAC is: MD5(key XOR opad, MD5(key XOR ipad, text))
 *
 * Init:
 * The initialization routine initializes what we denote
 * as the inner and outer contexts by doing
 * - for inner context: MD5(key XOR ipad)
 * - for outer context: MD5(key XOR opad)
 *
 * Update:
 * Each subsequent MD5 HMAC update will result in an
 * update of the inner context with the specified data.
 *
 * Final:
 * The MD5 HMAC final will do a MD5 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, an MD5 final on the outer context will
 * be performed to obtain the MD5 HMAC digest to return
 * to the user.
 */

/*
 * Initialize a MD5-HMAC context.
 */
static void
md5_mac_init_ctx(md5_hmac_ctx_t *ctx, void *keyval, uint_t length_in_bytes)
{
    uint32_t ipad[MD5_HMAC_INTS_PER_BLOCK];
    uint32_t opad[MD5_HMAC_INTS_PER_BLOCK];
    uint_t i;

    bzero(ipad, MD5_HMAC_BLOCK_SIZE);
    bzero(opad, MD5_HMAC_BLOCK_SIZE);

    bcopy(keyval, ipad, length_in_bytes);
    bcopy(keyval, opad, length_in_bytes);

    /* XOR key with ipad (0x36) and opad (0x5c) */
    for (i = 0; i < MD5_HMAC_INTS_PER_BLOCK; i++) {
        ipad[i] ^= 0x36363636;
        opad[i] ^= 0x5c5c5c5c;
    }

    /* perform MD5 on ipad */
    MD5Init(&ctx->hc_icontext);
    MD5Update(&ctx->hc_icontext, ipad, MD5_HMAC_BLOCK_SIZE);

    /* perform MD5 on opad */
    MD5Init(&ctx->hc_ocontext);
    MD5Update(&ctx->hc_ocontext, opad, MD5_HMAC_BLOCK_SIZE);
}

/*
 * Initializes a multi-part MAC operation.
 */
static int
md5_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);

    if (mechanism->cm_type != MD5_HMAC_MECH_INFO_TYPE &&
        mechanism->cm_type != MD5_HMAC_GEN_MECH_INFO_TYPE)
        return (CRYPTO_MECHANISM_INVALID);

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

    ctx->cc_provider_private = kmem_alloc(sizeof (md5_hmac_ctx_t),
        crypto_kmflag(req));
    if (ctx->cc_provider_private == NULL)
        return (CRYPTO_HOST_MEMORY);

    if (ctx_template != NULL) {
        /* reuse context template */
        bcopy(ctx_template, PROV_MD5_HMAC_CTX(ctx),
            sizeof (md5_hmac_ctx_t));
    } else {
        /* no context template, compute context */
        if (keylen_in_bytes > MD5_HMAC_BLOCK_SIZE) {
            uchar_t digested_key[MD5_DIGEST_LENGTH];
            md5_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_MD5_DIGEST_KEY(&hmac_ctx->hc_icontext,
                key->ck_data, keylen_in_bytes, digested_key);
            md5_mac_init_ctx(PROV_MD5_HMAC_CTX(ctx),
                digested_key, MD5_DIGEST_LENGTH);
        } else {
            md5_mac_init_ctx(PROV_MD5_HMAC_CTX(ctx),
                key->ck_data, keylen_in_bytes);
        }
    }

    /*
     * Get the mechanism parameters, if applicable.
     */
    PROV_MD5_HMAC_CTX(ctx)->hc_mech_type = mechanism->cm_type;
    if (mechanism->cm_type == MD5_HMAC_GEN_MECH_INFO_TYPE) {
        if (mechanism->cm_param == NULL ||
            mechanism->cm_param_len != sizeof (ulong_t))
            ret = CRYPTO_MECHANISM_PARAM_INVALID;
        PROV_MD5_GET_DIGEST_LEN(mechanism,
            PROV_MD5_HMAC_CTX(ctx)->hc_digest_len);
        if (PROV_MD5_HMAC_CTX(ctx)->hc_digest_len >
            MD5_DIGEST_LENGTH)
            ret = CRYPTO_MECHANISM_PARAM_INVALID;
    }

    if (ret != CRYPTO_SUCCESS) {
        bzero(ctx->cc_provider_private, sizeof (md5_hmac_ctx_t));
        kmem_free(ctx->cc_provider_private, sizeof (md5_hmac_ctx_t));
        ctx->cc_provider_private = NULL;
    }

    return (ret);
}


/* ARGSUSED */
static int
md5_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 an MD5 update of the inner context using the specified
     * data.
     */
    switch (data->cd_format) {
    case CRYPTO_DATA_RAW:
        MD5Update(&PROV_MD5_HMAC_CTX(ctx)->hc_icontext,
            data->cd_raw.iov_base + data->cd_offset,
            data->cd_length);
        break;
    case CRYPTO_DATA_UIO:
        ret = md5_digest_update_uio(
            &PROV_MD5_HMAC_CTX(ctx)->hc_icontext, data);
        break;
    case CRYPTO_DATA_MBLK:
        ret = md5_digest_update_mblk(
            &PROV_MD5_HMAC_CTX(ctx)->hc_icontext, data);
        break;
    default:
        ret = CRYPTO_ARGUMENTS_BAD;
    }

    return (ret);
}

/* ARGSUSED */
static int
md5_mac_final(crypto_ctx_t *ctx, crypto_data_t *mac, crypto_req_handle_t req)
{
    int ret = CRYPTO_SUCCESS;
    uchar_t digest[MD5_DIGEST_LENGTH];
    uint32_t digest_len = MD5_DIGEST_LENGTH;

    ASSERT(ctx->cc_provider_private != NULL);

    if (PROV_MD5_HMAC_CTX(ctx)->hc_mech_type == MD5_HMAC_GEN_MECH_INFO_TYPE)
        digest_len = PROV_MD5_HMAC_CTX(ctx)->hc_digest_len;

    /*
     * 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 an MD5 final on the inner context.
     */
    MD5Final(digest, &PROV_MD5_HMAC_CTX(ctx)->hc_icontext);

    /*
     * Do an MD5 update on the outer context, feeding the inner
     * digest as data.
     */
    MD5Update(&PROV_MD5_HMAC_CTX(ctx)->hc_ocontext, digest,
        MD5_DIGEST_LENGTH);

    /*
     * Do an MD5 final on the outer context, storing the computing
     * digest in the users buffer.
     */
    switch (mac->cd_format) {
    case CRYPTO_DATA_RAW:
        if (digest_len != MD5_DIGEST_LENGTH) {
            /*
             * The caller requested a short digest. Digest
             * into a scratch buffer and return to
             * the user only what was requested.
             */
            MD5Final(digest,
                &PROV_MD5_HMAC_CTX(ctx)->hc_ocontext);
            bcopy(digest, (unsigned char *)mac->cd_raw.iov_base +
                mac->cd_offset, digest_len);
        } else {
            MD5Final((unsigned char *)mac->cd_raw.iov_base +
                mac->cd_offset,
                &PROV_MD5_HMAC_CTX(ctx)->hc_ocontext);
        }
        break;
    case CRYPTO_DATA_UIO:
        ret = md5_digest_final_uio(
            &PROV_MD5_HMAC_CTX(ctx)->hc_ocontext, mac,
            digest_len, digest);
        break;
    case CRYPTO_DATA_MBLK:
        ret = md5_digest_final_mblk(
            &PROV_MD5_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 (md5_hmac_ctx_t));
    kmem_free(ctx->cc_provider_private, sizeof (md5_hmac_ctx_t));
    ctx->cc_provider_private = NULL;

    return (ret);
}

#define MD5_MAC_UPDATE(data, ctx, ret) {                \
    switch (data->cd_format) {                  \
    case CRYPTO_DATA_RAW:                       \
        MD5Update(&(ctx).hc_icontext,               \
            data->cd_raw.iov_base + data->cd_offset,        \
            data->cd_length);                   \
        break;                          \
    case CRYPTO_DATA_UIO:                       \
        ret = md5_digest_update_uio(&(ctx).hc_icontext, data);  \
        break;                          \
    case CRYPTO_DATA_MBLK:                      \
        ret = md5_digest_update_mblk(&(ctx).hc_icontext,    \
            data);                      \
        break;                          \
    default:                            \
        ret = CRYPTO_ARGUMENTS_BAD;             \
    }                               \
}


/* ARGSUSED */
static int
md5_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[MD5_DIGEST_LENGTH];
    md5_hmac_ctx_t md5_hmac_ctx;
    uint32_t digest_len = MD5_DIGEST_LENGTH;
    uint_t keylen_in_bytes = CRYPTO_BITS2BYTES(key->ck_length);

    if (mechanism->cm_type != MD5_HMAC_MECH_INFO_TYPE &&
        mechanism->cm_type != MD5_HMAC_GEN_MECH_INFO_TYPE)
        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, &md5_hmac_ctx, sizeof (md5_hmac_ctx_t));
    } else {
        /* no context template, compute context */
        if (keylen_in_bytes > MD5_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_MD5_DIGEST_KEY(&md5_hmac_ctx.hc_icontext,
                key->ck_data, keylen_in_bytes, digest);
            md5_mac_init_ctx(&md5_hmac_ctx, digest,
                MD5_DIGEST_LENGTH);
        } else {
            md5_mac_init_ctx(&md5_hmac_ctx, key->ck_data,
                keylen_in_bytes);
        }
    }

    /*
     * Get the mechanism parameters, if applicable.
     */
    if (mechanism->cm_type == MD5_HMAC_GEN_MECH_INFO_TYPE) {
        if (mechanism->cm_param == NULL ||
            mechanism->cm_param_len != sizeof (ulong_t)) {
            ret = CRYPTO_MECHANISM_PARAM_INVALID;
            goto bail;
        }
        PROV_MD5_GET_DIGEST_LEN(mechanism, digest_len);
        if (digest_len > MD5_DIGEST_LENGTH) {
            ret = CRYPTO_MECHANISM_PARAM_INVALID;
            goto bail;
        }
    }

    /* do an MD5 update of the inner context using the specified data */
    MD5_MAC_UPDATE(data, md5_hmac_ctx, ret);
    if (ret != CRYPTO_SUCCESS)
        /* the update failed, free context and bail */
        goto bail;

    /* do an MD5 final on the inner context */
    MD5Final(digest, &md5_hmac_ctx.hc_icontext);

    /*
     * Do an MD5 update on the outer context, feeding the inner
     * digest as data.
     */
    MD5Update(&md5_hmac_ctx.hc_ocontext, digest, MD5_DIGEST_LENGTH);

    /*
     * Do an MD5 final on the outer context, storing the computed
     * digest in the users buffer.
     */
    switch (mac->cd_format) {
    case CRYPTO_DATA_RAW:
        if (digest_len != MD5_DIGEST_LENGTH) {
            /*
             * The caller requested a short digest. Digest
             * into a scratch buffer and return to
             * the user only what was requested.
             */
            MD5Final(digest, &md5_hmac_ctx.hc_ocontext);
            bcopy(digest, (unsigned char *)mac->cd_raw.iov_base +
                mac->cd_offset, digest_len);
        } else {
            MD5Final((unsigned char *)mac->cd_raw.iov_base +
                mac->cd_offset, &md5_hmac_ctx.hc_ocontext);
        }
        break;
    case CRYPTO_DATA_UIO:
        ret = md5_digest_final_uio(&md5_hmac_ctx.hc_ocontext, mac,
            digest_len, digest);
        break;
    case CRYPTO_DATA_MBLK:
        ret = md5_digest_final_mblk(&md5_hmac_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;
    }
    /* Extra paranoia: zeroizing the local context on the stack */
    bzero(&md5_hmac_ctx, sizeof (md5_hmac_ctx_t));

    return (ret);
bail:
    bzero(&md5_hmac_ctx, sizeof (md5_hmac_ctx_t));
    mac->cd_length = 0;
    return (ret);
}

/* ARGSUSED */
static int
md5_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[MD5_DIGEST_LENGTH];
    md5_hmac_ctx_t md5_hmac_ctx;
    uint32_t digest_len = MD5_DIGEST_LENGTH;
    uint_t keylen_in_bytes = CRYPTO_BITS2BYTES(key->ck_length);

    if (mechanism->cm_type != MD5_HMAC_MECH_INFO_TYPE &&
        mechanism->cm_type != MD5_HMAC_GEN_MECH_INFO_TYPE)
        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, &md5_hmac_ctx, sizeof (md5_hmac_ctx_t));
    } else {
        /* no context template, compute context */
        if (keylen_in_bytes > MD5_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_MD5_DIGEST_KEY(&md5_hmac_ctx.hc_icontext,
                key->ck_data, keylen_in_bytes, digest);
            md5_mac_init_ctx(&md5_hmac_ctx, digest,
                MD5_DIGEST_LENGTH);
        } else {
            md5_mac_init_ctx(&md5_hmac_ctx, key->ck_data,
                keylen_in_bytes);
        }
    }

    /*
     * Get the mechanism parameters, if applicable.
     */
    if (mechanism->cm_type == MD5_HMAC_GEN_MECH_INFO_TYPE) {
        if (mechanism->cm_param == NULL ||
            mechanism->cm_param_len != sizeof (ulong_t)) {
            ret = CRYPTO_MECHANISM_PARAM_INVALID;
            goto bail;
        }
        PROV_MD5_GET_DIGEST_LEN(mechanism, digest_len);
        if (digest_len > MD5_DIGEST_LENGTH) {
            ret = CRYPTO_MECHANISM_PARAM_INVALID;
            goto bail;
        }
    }

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

    /* do an MD5 update of the inner context using the specified data */
    MD5_MAC_UPDATE(data, md5_hmac_ctx, ret);
    if (ret != CRYPTO_SUCCESS)
        /* the update failed, free context and bail */
        goto bail;

    /* do an MD5 final on the inner context */
    MD5Final(digest, &md5_hmac_ctx.hc_icontext);

    /*
     * Do an MD5 update on the outer context, feeding the inner
     * digest as data.
     */
    MD5Update(&md5_hmac_ctx.hc_ocontext, digest, MD5_DIGEST_LENGTH);

    /*
     * Do an MD5 final on the outer context, storing the computed
     * digest in the local digest buffer.
     */
    MD5Final(digest, &md5_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;
    }

    case CRYPTO_DATA_MBLK: {
        off_t offset = mac->cd_offset;
        mblk_t *mp;
        off_t scratch_offset = 0;
        size_t length = digest_len;
        size_t cur_len;

        /* jump to the first mblk_t containing the expected digest */
        for (mp = mac->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.
             */
            ret = CRYPTO_DATA_LEN_RANGE;
            break;
        }

        while (mp != NULL && length > 0) {
            cur_len = MIN(MBLKL(mp) - offset, length);
            if (bcmp(digest + scratch_offset,
                mp->b_rptr + offset, cur_len) != 0) {
                ret = CRYPTO_INVALID_MAC;
                break;
            }

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

    default:
        ret = CRYPTO_ARGUMENTS_BAD;
    }

    bzero(&md5_hmac_ctx, sizeof (md5_hmac_ctx_t));
    return (ret);
bail:
    bzero(&md5_hmac_ctx, sizeof (md5_hmac_ctx_t));
    mac->cd_length = 0;
    return (ret);
}

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

/* ARGSUSED */
static int
md5_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)
{
    md5_hmac_ctx_t *md5_hmac_ctx_tmpl;
    uint_t keylen_in_bytes = CRYPTO_BITS2BYTES(key->ck_length);

    if ((mechanism->cm_type != MD5_HMAC_MECH_INFO_TYPE) &&
        (mechanism->cm_type != MD5_HMAC_GEN_MECH_INFO_TYPE))
        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 MD5 context.
     */
    md5_hmac_ctx_tmpl = kmem_alloc(sizeof (md5_hmac_ctx_t),
        crypto_kmflag(req));
    if (md5_hmac_ctx_tmpl == NULL)
        return (CRYPTO_HOST_MEMORY);

    if (keylen_in_bytes > MD5_HMAC_BLOCK_SIZE) {
        uchar_t digested_key[MD5_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_MD5_DIGEST_KEY(&md5_hmac_ctx_tmpl->hc_icontext,
            key->ck_data, keylen_in_bytes, digested_key);
        md5_mac_init_ctx(md5_hmac_ctx_tmpl, digested_key,
            MD5_DIGEST_LENGTH);
    } else {
        md5_mac_init_ctx(md5_hmac_ctx_tmpl, key->ck_data,
            keylen_in_bytes);
    }

    md5_hmac_ctx_tmpl->hc_mech_type = mechanism->cm_type;
    *ctx_template = (crypto_spi_ctx_template_t)md5_hmac_ctx_tmpl;
    *ctx_template_size = sizeof (md5_hmac_ctx_t);

    return (CRYPTO_SUCCESS);
}

static int
md5_free_context(crypto_ctx_t *ctx)
{
    uint_t ctx_len;
    md5_mech_type_t mech_type;

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

    /*
     * We have to free either MD5 or MD5-HMAC contexts, which
     * have different lengths.
     */

    mech_type = PROV_MD5_CTX(ctx)->mc_mech_type;
    if (mech_type == MD5_MECH_INFO_TYPE)
        ctx_len = sizeof (md5_ctx_t);
    else {
        ASSERT(mech_type == MD5_HMAC_MECH_INFO_TYPE ||
            mech_type == MD5_HMAC_GEN_MECH_INFO_TYPE);
        ctx_len = sizeof (md5_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);
}

#endif  /* _KERNEL && !_BOOT */