[thirdparty/openssl.git] / providers / common / kdfs / sskdf.c

/*
 * Copyright 2019 The OpenSSL Project Authors. All Rights Reserved.
 * Copyright (c) 2019, Oracle and/or its affiliates.  All rights reserved.
 *
 * Licensed under the Apache License 2.0 (the "License").  You may not use
 * this file except in compliance with the License.  You can obtain a copy
 * in the file LICENSE in the source distribution or at
 * https://www.openssl.org/source/license.html
 */

/*
 * Refer to https://csrc.nist.gov/publications/detail/sp/800-56c/rev-1/final
 * Section 4.1.
 *
 * The Single Step KDF algorithm is given by:
 *
 * Result(0) = empty bit string (i.e., the null string).
 * For i = 1 to reps, do the following:
 *   Increment counter by 1.
 *   Result(i) = Result(i - 1) || H(counter || Z || FixedInfo).
 * DKM = LeftmostBits(Result(reps), L))
 *
 * NOTES:
 *   Z is a shared secret required to produce the derived key material.
 *   counter is a 4 byte buffer.
 *   FixedInfo is a bit string containing context specific data.
 *   DKM is the output derived key material.
 *   L is the required size of the DKM.
 *   reps = [L / H_outputBits]
 *   H(x) is the auxiliary function that can be either a hash, HMAC or KMAC.
 *   H_outputBits is the length of the output of the auxiliary function H(x).
 *
 * Currently there is not a comprehensive list of test vectors for this
 * algorithm, especially for H(x) = HMAC and H(x) = KMAC.
 * Test vectors for H(x) = Hash are indirectly used by CAVS KAS tests.
 */
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <openssl/hmac.h>
#include <openssl/evp.h>
#include <openssl/kdf.h>
#include <openssl/core_names.h>
#include <openssl/params.h>
#include "internal/cryptlib.h"
#include "internal/numbers.h"
#include "internal/evp_int.h"
#include "internal/provider_ctx.h"
#include "internal/providercommonerr.h"
#include "internal/provider_algs.h"
#include "internal/provider_util.h"

typedef struct {
    void *provctx;
    EVP_MAC_CTX *macctx;         /* H(x) = HMAC_hash OR H(x) = KMAC */
    PROV_DIGEST digest;          /* H(x) = hash(x) */
    unsigned char *secret;
    size_t secret_len;
    unsigned char *info;
    size_t info_len;
    unsigned char *salt;
    size_t salt_len;
    size_t out_len; /* optional KMAC parameter */
} KDF_SSKDF;

#define SSKDF_MAX_INLEN (1<<30)
#define SSKDF_KMAC128_DEFAULT_SALT_SIZE (168 - 4)
#define SSKDF_KMAC256_DEFAULT_SALT_SIZE (136 - 4)

/* KMAC uses a Customisation string of 'KDF' */
static const unsigned char kmac_custom_str[] = { 0x4B, 0x44, 0x46 };

static OSSL_OP_kdf_newctx_fn sskdf_new;
static OSSL_OP_kdf_freectx_fn sskdf_free;
static OSSL_OP_kdf_reset_fn sskdf_reset;
static OSSL_OP_kdf_derive_fn sskdf_derive;
static OSSL_OP_kdf_derive_fn x963kdf_derive;
static OSSL_OP_kdf_settable_ctx_params_fn sskdf_settable_ctx_params;
static OSSL_OP_kdf_set_ctx_params_fn sskdf_set_ctx_params;
static OSSL_OP_kdf_gettable_ctx_params_fn sskdf_gettable_ctx_params;
static OSSL_OP_kdf_get_ctx_params_fn sskdf_get_ctx_params;

/*
 * Refer to https://csrc.nist.gov/publications/detail/sp/800-56c/rev-1/final
 * Section 4. One-Step Key Derivation using H(x) = hash(x)
 * Note: X9.63 also uses this code with the only difference being that the
 * counter is appended to the secret 'z'.
 * i.e.
 *   result[i] = Hash(counter || z || info) for One Step OR
 *   result[i] = Hash(z || counter || info) for X9.63.
 */
static int SSKDF_hash_kdm(const EVP_MD *kdf_md,
                          const unsigned char *z, size_t z_len,
                          const unsigned char *info, size_t info_len,
                          unsigned int append_ctr,
                          unsigned char *derived_key, size_t derived_key_len)
{
    int ret = 0, hlen;
    size_t counter, out_len, len = derived_key_len;
    unsigned char c[4];
    unsigned char mac[EVP_MAX_MD_SIZE];
    unsigned char *out = derived_key;
    EVP_MD_CTX *ctx = NULL, *ctx_init = NULL;

    if (z_len > SSKDF_MAX_INLEN || info_len > SSKDF_MAX_INLEN
            || derived_key_len > SSKDF_MAX_INLEN
            || derived_key_len == 0)
        return 0;

    hlen = EVP_MD_size(kdf_md);
    if (hlen <= 0)
        return 0;
    out_len = (size_t)hlen;

    ctx = EVP_MD_CTX_create();
    ctx_init = EVP_MD_CTX_create();
    if (ctx == NULL || ctx_init == NULL)
        goto end;

    if (!EVP_DigestInit(ctx_init, kdf_md))
        goto end;

    for (counter = 1;; counter++) {
        c[0] = (unsigned char)((counter >> 24) & 0xff);
        c[1] = (unsigned char)((counter >> 16) & 0xff);
        c[2] = (unsigned char)((counter >> 8) & 0xff);
        c[3] = (unsigned char)(counter & 0xff);

        if (!(EVP_MD_CTX_copy_ex(ctx, ctx_init)
                && (append_ctr || EVP_DigestUpdate(ctx, c, sizeof(c)))
                && EVP_DigestUpdate(ctx, z, z_len)
                && (!append_ctr || EVP_DigestUpdate(ctx, c, sizeof(c)))
                && EVP_DigestUpdate(ctx, info, info_len)))
            goto end;
        if (len >= out_len) {
            if (!EVP_DigestFinal_ex(ctx, out, NULL))
                goto end;
            out += out_len;
            len -= out_len;
            if (len == 0)
                break;
        } else {
            if (!EVP_DigestFinal_ex(ctx, mac, NULL))
                goto end;
            memcpy(out, mac, len);
            break;
        }
    }
    ret = 1;
end:
    EVP_MD_CTX_destroy(ctx);
    EVP_MD_CTX_destroy(ctx_init);
    OPENSSL_cleanse(mac, sizeof(mac));
    return ret;
}

static int kmac_init(EVP_MAC_CTX *ctx, const unsigned char *custom,
                     size_t custom_len, size_t kmac_out_len,
                     size_t derived_key_len, unsigned char **out)
{
    OSSL_PARAM params[2];

    /* Only KMAC has custom data - so return if not KMAC */
    if (custom == NULL)
        return 1;

    params[0] = OSSL_PARAM_construct_octet_string(OSSL_MAC_PARAM_CUSTOM,
                                                  (void *)custom, custom_len);
    params[1] = OSSL_PARAM_construct_end();

    if (!EVP_MAC_CTX_set_params(ctx, params))
        return 0;

    /* By default only do one iteration if kmac_out_len is not specified */
    if (kmac_out_len == 0)
        kmac_out_len = derived_key_len;
    /* otherwise check the size is valid */
    else if (!(kmac_out_len == derived_key_len
            || kmac_out_len == 20
            || kmac_out_len == 28
            || kmac_out_len == 32
            || kmac_out_len == 48
            || kmac_out_len == 64))
        return 0;

    params[0] = OSSL_PARAM_construct_size_t(OSSL_MAC_PARAM_SIZE,
                                            &kmac_out_len);

    if (EVP_MAC_CTX_set_params(ctx, params) <= 0)
        return 0;

    /*
     * For kmac the output buffer can be larger than EVP_MAX_MD_SIZE: so
     * alloc a buffer for this case.
     */
    if (kmac_out_len > EVP_MAX_MD_SIZE) {
        *out = OPENSSL_zalloc(kmac_out_len);
        if (*out == NULL)
            return 0;
    }
    return 1;
}

/*
 * Refer to https://csrc.nist.gov/publications/detail/sp/800-56c/rev-1/final
 * Section 4. One-Step Key Derivation using MAC: i.e either
 *     H(x) = HMAC-hash(salt, x) OR
 *     H(x) = KMAC#(salt, x, outbits, CustomString='KDF')
 */
static int SSKDF_mac_kdm(EVP_MAC_CTX *ctx_init,
                         const unsigned char *kmac_custom,
                         size_t kmac_custom_len, size_t kmac_out_len,
                         const unsigned char *salt, size_t salt_len,
                         const unsigned char *z, size_t z_len,
                         const unsigned char *info, size_t info_len,
                         unsigned char *derived_key, size_t derived_key_len)
{
    int ret = 0;
    size_t counter, out_len, len;
    unsigned char c[4];
    unsigned char mac_buf[EVP_MAX_MD_SIZE];
    unsigned char *out = derived_key;
    EVP_MAC_CTX *ctx = NULL;
    unsigned char *mac = mac_buf, *kmac_buffer = NULL;
    OSSL_PARAM params[2], *p = params;

    if (z_len > SSKDF_MAX_INLEN || info_len > SSKDF_MAX_INLEN
            || derived_key_len > SSKDF_MAX_INLEN
            || derived_key_len == 0)
        return 0;

    *p++ = OSSL_PARAM_construct_octet_string(OSSL_MAC_PARAM_KEY,
                                             (void *)salt, salt_len);
    *p = OSSL_PARAM_construct_end();

    if (!EVP_MAC_CTX_set_params(ctx_init, params))
        goto end;

    if (!kmac_init(ctx_init, kmac_custom, kmac_custom_len, kmac_out_len,
                   derived_key_len, &kmac_buffer))
        goto end;
    if (kmac_buffer != NULL)
        mac = kmac_buffer;

    if (!EVP_MAC_init(ctx_init))
        goto end;

    out_len = EVP_MAC_size(ctx_init); /* output size */
    if (out_len <= 0)
        goto end;
    len = derived_key_len;

    for (counter = 1;; counter++) {
        c[0] = (unsigned char)((counter >> 24) & 0xff);
        c[1] = (unsigned char)((counter >> 16) & 0xff);
        c[2] = (unsigned char)((counter >> 8) & 0xff);
        c[3] = (unsigned char)(counter & 0xff);

        ctx = EVP_MAC_CTX_dup(ctx_init);
        if (!(ctx != NULL
                && EVP_MAC_update(ctx, c, sizeof(c))
                && EVP_MAC_update(ctx, z, z_len)
                && EVP_MAC_update(ctx, info, info_len)))
            goto end;
        if (len >= out_len) {
            if (!EVP_MAC_final(ctx, out, NULL, len))
                goto end;
            out += out_len;
            len -= out_len;
            if (len == 0)
                break;
        } else {
            if (!EVP_MAC_final(ctx, mac, NULL, len))
                goto end;
            memcpy(out, mac, len);
            break;
        }
        EVP_MAC_CTX_free(ctx);
        ctx = NULL;
    }
    ret = 1;
end:
    if (kmac_buffer != NULL)
        OPENSSL_clear_free(kmac_buffer, kmac_out_len);
    else
        OPENSSL_cleanse(mac_buf, sizeof(mac_buf));

    EVP_MAC_CTX_free(ctx);
    return ret;
}

static void *sskdf_new(void *provctx)
{
    KDF_SSKDF *ctx;

    if ((ctx = OPENSSL_zalloc(sizeof(*ctx))) == NULL)
        ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE);
    ctx->provctx = provctx;
    return ctx;
}

static void sskdf_reset(void *vctx)
{
    KDF_SSKDF *ctx = (KDF_SSKDF *)vctx;

    EVP_MAC_CTX_free(ctx->macctx);
    ossl_prov_digest_reset(&ctx->digest);
    OPENSSL_clear_free(ctx->secret, ctx->secret_len);
    OPENSSL_clear_free(ctx->info, ctx->info_len);
    OPENSSL_clear_free(ctx->salt, ctx->salt_len);
    memset(ctx, 0, sizeof(*ctx));
}

static void sskdf_free(void *vctx)
{
    KDF_SSKDF *ctx = (KDF_SSKDF *)vctx;

    sskdf_reset(ctx);
    OPENSSL_free(ctx);
}

static int sskdf_set_buffer(unsigned char **out, size_t *out_len,
                            const OSSL_PARAM *p)
{
    if (p->data == NULL || p->data_size == 0)
        return 1;
    OPENSSL_free(*out);
    *out = NULL;
    return OSSL_PARAM_get_octet_string(p, (void **)out, 0, out_len);
}

static size_t sskdf_size(KDF_SSKDF *ctx)
{
    int len;
    const EVP_MD *md = ossl_prov_digest_md(&ctx->digest);

    if (md == NULL) {
        ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MESSAGE_DIGEST);
        return 0;
    }
    len = EVP_MD_size(md);
    return (len <= 0) ? 0 : (size_t)len;
}

static int sskdf_derive(void *vctx, unsigned char *key, size_t keylen)
{
    KDF_SSKDF *ctx = (KDF_SSKDF *)vctx;
    const EVP_MD *md = ossl_prov_digest_md(&ctx->digest);

    if (ctx->secret == NULL) {
        ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_SECRET);
        return 0;
    }

    if (ctx->macctx != NULL) {
        /* H(x) = KMAC or H(x) = HMAC */
        int ret;
        const unsigned char *custom = NULL;
        size_t custom_len = 0;
        int default_salt_len;
        EVP_MAC *mac = EVP_MAC_CTX_mac(ctx->macctx);

        /*
         * TODO(3.0) investigate the necessity to have all these controls.
         * Why does KMAC require a salt length that's shorter than the MD
         * block size?
         */
        if (EVP_MAC_is_a(mac, OSSL_MAC_NAME_HMAC)) {
            /* H(x) = HMAC(x, salt, hash) */
            if (md == NULL) {
                ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MESSAGE_DIGEST);
                return 0;
            }
            default_salt_len = EVP_MD_size(md);
            if (default_salt_len <= 0)
                return 0;
        } else if (EVP_MAC_is_a(mac, OSSL_MAC_NAME_KMAC128)
                   || EVP_MAC_is_a(mac, OSSL_MAC_NAME_KMAC256)) {
            /* H(x) = KMACzzz(x, salt, custom) */
            custom = kmac_custom_str;
            custom_len = sizeof(kmac_custom_str);
            if (EVP_MAC_is_a(mac, OSSL_MAC_NAME_KMAC128))
                default_salt_len = SSKDF_KMAC128_DEFAULT_SALT_SIZE;
            else
                default_salt_len = SSKDF_KMAC256_DEFAULT_SALT_SIZE;
        } else {
            ERR_raise(ERR_LIB_PROV, PROV_R_UNSUPPORTED_MAC_TYPE);
            return 0;
        }
        /* If no salt is set then use a default_salt of zeros */
        if (ctx->salt == NULL || ctx->salt_len <= 0) {
            ctx->salt = OPENSSL_zalloc(default_salt_len);
            if (ctx->salt == NULL) {
                ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE);
                return 0;
            }
            ctx->salt_len = default_salt_len;
        }
        ret = SSKDF_mac_kdm(ctx->macctx,
                            custom, custom_len, ctx->out_len,
                            ctx->salt, ctx->salt_len,
                            ctx->secret, ctx->secret_len,
                            ctx->info, ctx->info_len, key, keylen);
        return ret;
    } else {
        /* H(x) = hash */
        if (md == NULL) {
            ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MESSAGE_DIGEST);
            return 0;
        }
        return SSKDF_hash_kdm(md, ctx->secret, ctx->secret_len,
                              ctx->info, ctx->info_len, 0, key, keylen);
    }
}

static int x963kdf_derive(void *vctx, unsigned char *key, size_t keylen)
{
    KDF_SSKDF *ctx = (KDF_SSKDF *)vctx;
    const EVP_MD *md = ossl_prov_digest_md(&ctx->digest);

    if (ctx->secret == NULL) {
        ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_SECRET);
        return 0;
    }

    if (ctx->macctx != NULL) {
        ERR_raise(ERR_LIB_PROV, PROV_R_NOT_SUPPORTED);
        return 0;
    }

    /* H(x) = hash */
    if (md == NULL) {
        ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MESSAGE_DIGEST);
        return 0;
    }

    return SSKDF_hash_kdm(md, ctx->secret, ctx->secret_len,
                          ctx->info, ctx->info_len, 1, key, keylen);
}

static int sskdf_set_ctx_params(void *vctx, const OSSL_PARAM params[])
{
    const OSSL_PARAM *p;
    KDF_SSKDF *ctx = vctx;
    OPENSSL_CTX *libctx = PROV_LIBRARY_CONTEXT_OF(ctx->provctx);
    size_t sz;

    if (!ossl_prov_digest_load_from_params(&ctx->digest, params, libctx))
        return 0;

    if (!ossl_prov_macctx_load_from_params(&ctx->macctx, params,
                                           NULL, NULL, NULL, libctx))
        return 0;

    if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SECRET)) != NULL
        || (p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_KEY)) != NULL)
        if (!sskdf_set_buffer(&ctx->secret, &ctx->secret_len, p))
            return 0;

    if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_INFO)) != NULL)
        if (!sskdf_set_buffer(&ctx->info, &ctx->info_len, p))
            return 0;

    if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SALT)) != NULL)
        if (!sskdf_set_buffer(&ctx->salt, &ctx->salt_len, p))
            return 0;

    if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_MAC_SIZE))
        != NULL) {
        if (!OSSL_PARAM_get_size_t(p, &sz) || sz == 0)
            return 0;
        ctx->out_len = sz;
    }
    return 1;
}

static const OSSL_PARAM *sskdf_settable_ctx_params(void)
{
    static const OSSL_PARAM known_settable_ctx_params[] = {
        OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SECRET, NULL, 0),
        OSSL_PARAM_octet_string(OSSL_KDF_PARAM_KEY, NULL, 0),
        OSSL_PARAM_octet_string(OSSL_KDF_PARAM_INFO, NULL, 0),
        OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_PROPERTIES, NULL, 0),
        OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_DIGEST, NULL, 0),
        OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_MAC, NULL, 0),
        OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SALT, NULL, 0),
        OSSL_PARAM_size_t(OSSL_KDF_PARAM_MAC_SIZE, NULL),
        OSSL_PARAM_END
    };
    return known_settable_ctx_params;
}

static int sskdf_get_ctx_params(void *vctx, OSSL_PARAM params[])
{
    KDF_SSKDF *ctx = (KDF_SSKDF *)vctx;
    OSSL_PARAM *p;

    if ((p = OSSL_PARAM_locate(params, OSSL_KDF_PARAM_SIZE)) != NULL)
        return OSSL_PARAM_set_size_t(p, sskdf_size(ctx));
    return -2;
}

static const OSSL_PARAM *sskdf_gettable_ctx_params(void)
{
    static const OSSL_PARAM known_gettable_ctx_params[] = {
        OSSL_PARAM_size_t(OSSL_KDF_PARAM_SIZE, NULL),
        OSSL_PARAM_END
    };
    return known_gettable_ctx_params;
}

const OSSL_DISPATCH kdf_sskdf_functions[] = {
    { OSSL_FUNC_KDF_NEWCTX, (void(*)(void))sskdf_new },
    { OSSL_FUNC_KDF_FREECTX, (void(*)(void))sskdf_free },
    { OSSL_FUNC_KDF_RESET, (void(*)(void))sskdf_reset },
    { OSSL_FUNC_KDF_DERIVE, (void(*)(void))sskdf_derive },
    { OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS,
      (void(*)(void))sskdf_settable_ctx_params },
    { OSSL_FUNC_KDF_SET_CTX_PARAMS, (void(*)(void))sskdf_set_ctx_params },
    { OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS,
      (void(*)(void))sskdf_gettable_ctx_params },
    { OSSL_FUNC_KDF_GET_CTX_PARAMS, (void(*)(void))sskdf_get_ctx_params },
    { 0, NULL }
};

const OSSL_DISPATCH kdf_x963_kdf_functions[] = {
    { OSSL_FUNC_KDF_NEWCTX, (void(*)(void))sskdf_new },
    { OSSL_FUNC_KDF_FREECTX, (void(*)(void))sskdf_free },
    { OSSL_FUNC_KDF_RESET, (void(*)(void))sskdf_reset },
    { OSSL_FUNC_KDF_DERIVE, (void(*)(void))x963kdf_derive },
    { OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS,
      (void(*)(void))sskdf_settable_ctx_params },
    { OSSL_FUNC_KDF_SET_CTX_PARAMS, (void(*)(void))sskdf_set_ctx_params },
    { OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS,
      (void(*)(void))sskdf_gettable_ctx_params },
    { OSSL_FUNC_KDF_GET_CTX_PARAMS, (void(*)(void))sskdf_get_ctx_params },
    { 0, NULL }
};
Commit	Line	Data
9537fe57 SL	1	/*
	2	* Copyright 2019 The OpenSSL Project Authors. All Rights Reserved.
	3	* Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
	4	*
	5	* Licensed under the Apache License 2.0 (the "License"). You may not use
	6	* this file except in compliance with the License. You can obtain a copy
	7	* in the file LICENSE in the source distribution or at
	8	* https://www.openssl.org/source/license.html
	9	*/
	10
	11	/*
	12	* Refer to https://csrc.nist.gov/publications/detail/sp/800-56c/rev-1/final
	13	* Section 4.1.
	14	*
	15	* The Single Step KDF algorithm is given by:
	16	*
	17	* Result(0) = empty bit string (i.e., the null string).
	18	* For i = 1 to reps, do the following:
	19	* Increment counter by 1.
7a228c39	20	* Result(i) = Result(i - 1) \|\| H(counter \|\| Z \|\| FixedInfo).
9537fe57 SL	21	* DKM = LeftmostBits(Result(reps), L))
	22	*
	23	* NOTES:
	24	* Z is a shared secret required to produce the derived key material.
	25	* counter is a 4 byte buffer.
	26	* FixedInfo is a bit string containing context specific data.
	27	* DKM is the output derived key material.
	28	* L is the required size of the DKM.
	29	* reps = [L / H_outputBits]
	30	* H(x) is the auxiliary function that can be either a hash, HMAC or KMAC.
	31	* H_outputBits is the length of the output of the auxiliary function H(x).
	32	*
	33	* Currently there is not a comprehensive list of test vectors for this
	34	* algorithm, especially for H(x) = HMAC and H(x) = KMAC.
	35	* Test vectors for H(x) = Hash are indirectly used by CAVS KAS tests.
	36	*/
	37	#include <stdlib.h>
	38	#include <stdarg.h>
	39	#include <string.h>
	40	#include <openssl/hmac.h>
	41	#include <openssl/evp.h>
	42	#include <openssl/kdf.h>
776796e8 RL	43	#include <openssl/core_names.h>
776796e8 RL	44	#include <openssl/params.h>
9537fe57	45	#include "internal/cryptlib.h"
e3405a4a	46	#include "internal/numbers.h"
9537fe57	47	#include "internal/evp_int.h"
e3405a4a P	48	#include "internal/provider_ctx.h"
	49	#include "internal/providercommonerr.h"
	50	#include "internal/provider_algs.h"
7e149b39	51	#include "internal/provider_util.h"
9537fe57	52
e3405a4a P	53	typedef struct {
e3405a4a P	54	void *provctx;
d3386f77 RL	55	EVP_MAC_CTX macctx; / H(x) = HMAC_hash OR H(x) = KMAC */
d3386f77 RL	56	PROV_DIGEST digest; /* H(x) = hash(x) */
9537fe57 SL	57	unsigned char *secret;
	58	size_t secret_len;
	59	unsigned char *info;
	60	size_t info_len;
	61	unsigned char *salt;
	62	size_t salt_len;
	63	size_t out_len; /* optional KMAC parameter */
e3405a4a	64	} KDF_SSKDF;
9537fe57 SL	65
	66	#define SSKDF_MAX_INLEN (1<<30)
	67	#define SSKDF_KMAC128_DEFAULT_SALT_SIZE (168 - 4)
	68	#define SSKDF_KMAC256_DEFAULT_SALT_SIZE (136 - 4)
	69
	70	/* KMAC uses a Customisation string of 'KDF' */
	71	static const unsigned char kmac_custom_str[] = { 0x4B, 0x44, 0x46 };
	72
e3405a4a P	73	static OSSL_OP_kdf_newctx_fn sskdf_new;
	74	static OSSL_OP_kdf_freectx_fn sskdf_free;
	75	static OSSL_OP_kdf_reset_fn sskdf_reset;
	76	static OSSL_OP_kdf_derive_fn sskdf_derive;
	77	static OSSL_OP_kdf_derive_fn x963kdf_derive;
	78	static OSSL_OP_kdf_settable_ctx_params_fn sskdf_settable_ctx_params;
	79	static OSSL_OP_kdf_set_ctx_params_fn sskdf_set_ctx_params;
	80	static OSSL_OP_kdf_gettable_ctx_params_fn sskdf_gettable_ctx_params;
	81	static OSSL_OP_kdf_get_ctx_params_fn sskdf_get_ctx_params;
	82
9537fe57 SL	83	/*
	84	* Refer to https://csrc.nist.gov/publications/detail/sp/800-56c/rev-1/final
	85	* Section 4. One-Step Key Derivation using H(x) = hash(x)
8bbeaaa4 SL	86	* Note: X9.63 also uses this code with the only difference being that the
	87	* counter is appended to the secret 'z'.
	88	* i.e.
	89	* result[i] = Hash(counter \|\| z \|\| info) for One Step OR
	90	* result[i] = Hash(z \|\| counter \|\| info) for X9.63.
9537fe57 SL	91	*/
	92	static int SSKDF_hash_kdm(const EVP_MD *kdf_md,
	93	const unsigned char *z, size_t z_len,
	94	const unsigned char *info, size_t info_len,
8bbeaaa4	95	unsigned int append_ctr,
9537fe57 SL	96	unsigned char *derived_key, size_t derived_key_len)
	97	{
	98	int ret = 0, hlen;
	99	size_t counter, out_len, len = derived_key_len;
	100	unsigned char c[4];
	101	unsigned char mac[EVP_MAX_MD_SIZE];
	102	unsigned char *out = derived_key;
	103	EVP_MD_CTX ctx = NULL, ctx_init = NULL;
	104
	105	if (z_len > SSKDF_MAX_INLEN \|\| info_len > SSKDF_MAX_INLEN
	106	\|\| derived_key_len > SSKDF_MAX_INLEN
	107	\|\| derived_key_len == 0)
	108	return 0;
	109
	110	hlen = EVP_MD_size(kdf_md);
	111	if (hlen <= 0)
	112	return 0;
	113	out_len = (size_t)hlen;
	114
	115	ctx = EVP_MD_CTX_create();
	116	ctx_init = EVP_MD_CTX_create();
	117	if (ctx == NULL \|\| ctx_init == NULL)
	118	goto end;
	119
	120	if (!EVP_DigestInit(ctx_init, kdf_md))
	121	goto end;
	122
	123	for (counter = 1;; counter++) {
	124	c[0] = (unsigned char)((counter >> 24) & 0xff);
	125	c[1] = (unsigned char)((counter >> 16) & 0xff);
	126	c[2] = (unsigned char)((counter >> 8) & 0xff);
	127	c[3] = (unsigned char)(counter & 0xff);
	128
	129	if (!(EVP_MD_CTX_copy_ex(ctx, ctx_init)
8bbeaaa4	130	&& (append_ctr \|\| EVP_DigestUpdate(ctx, c, sizeof(c)))
9537fe57	131	&& EVP_DigestUpdate(ctx, z, z_len)
8bbeaaa4	132	&& (!append_ctr \|\| EVP_DigestUpdate(ctx, c, sizeof(c)))
9537fe57 SL	133	&& EVP_DigestUpdate(ctx, info, info_len)))
	134	goto end;
	135	if (len >= out_len) {
	136	if (!EVP_DigestFinal_ex(ctx, out, NULL))
	137	goto end;
	138	out += out_len;
	139	len -= out_len;
	140	if (len == 0)
	141	break;
	142	} else {
	143	if (!EVP_DigestFinal_ex(ctx, mac, NULL))
	144	goto end;
	145	memcpy(out, mac, len);
	146	break;
	147	}
	148	}
	149	ret = 1;
	150	end:
	151	EVP_MD_CTX_destroy(ctx);
	152	EVP_MD_CTX_destroy(ctx_init);
	153	OPENSSL_cleanse(mac, sizeof(mac));
	154	return ret;
	155	}
	156
	157	static int kmac_init(EVP_MAC_CTX ctx, const unsigned char custom,
	158	size_t custom_len, size_t kmac_out_len,
	159	size_t derived_key_len, unsigned char **out)
	160	{
776796e8 RL	161	OSSL_PARAM params[2];
776796e8 RL	162
9537fe57 SL	163	/* Only KMAC has custom data - so return if not KMAC */
	164	if (custom == NULL)
	165	return 1;
	166
776796e8 RL	167	params[0] = OSSL_PARAM_construct_octet_string(OSSL_MAC_PARAM_CUSTOM,
	168	(void *)custom, custom_len);
	169	params[1] = OSSL_PARAM_construct_end();
	170
	171	if (!EVP_MAC_CTX_set_params(ctx, params))
9537fe57 SL	172	return 0;
	173
	174	/* By default only do one iteration if kmac_out_len is not specified */
	175	if (kmac_out_len == 0)
	176	kmac_out_len = derived_key_len;
	177	/* otherwise check the size is valid */
	178	else if (!(kmac_out_len == derived_key_len
	179	\|\| kmac_out_len == 20
	180	\|\| kmac_out_len == 28
	181	\|\| kmac_out_len == 32
	182	\|\| kmac_out_len == 48
	183	\|\| kmac_out_len == 64))
	184	return 0;
	185
703170d4	186	params[0] = OSSL_PARAM_construct_size_t(OSSL_MAC_PARAM_SIZE,
776796e8 RL	187	&kmac_out_len);
	188
	189	if (EVP_MAC_CTX_set_params(ctx, params) <= 0)
9537fe57 SL	190	return 0;
	191
	192	/*
	193	* For kmac the output buffer can be larger than EVP_MAX_MD_SIZE: so
	194	* alloc a buffer for this case.
	195	*/
	196	if (kmac_out_len > EVP_MAX_MD_SIZE) {
	197	*out = OPENSSL_zalloc(kmac_out_len);
	198	if (*out == NULL)
	199	return 0;
	200	}
	201	return 1;
	202	}
	203
	204	/*
	205	* Refer to https://csrc.nist.gov/publications/detail/sp/800-56c/rev-1/final
	206	* Section 4. One-Step Key Derivation using MAC: i.e either
	207	* H(x) = HMAC-hash(salt, x) OR
	208	* H(x) = KMAC#(salt, x, outbits, CustomString='KDF')
	209	*/
d3386f77	210	static int SSKDF_mac_kdm(EVP_MAC_CTX *ctx_init,
9537fe57 SL	211	const unsigned char *kmac_custom,
	212	size_t kmac_custom_len, size_t kmac_out_len,
	213	const unsigned char *salt, size_t salt_len,
	214	const unsigned char *z, size_t z_len,
	215	const unsigned char *info, size_t info_len,
	216	unsigned char *derived_key, size_t derived_key_len)
	217	{
	218	int ret = 0;
	219	size_t counter, out_len, len;
	220	unsigned char c[4];
	221	unsigned char mac_buf[EVP_MAX_MD_SIZE];
	222	unsigned char *out = derived_key;
d3386f77	223	EVP_MAC_CTX *ctx = NULL;
9537fe57	224	unsigned char mac = mac_buf, kmac_buffer = NULL;
d3386f77	225	OSSL_PARAM params[2], *p = params;
9537fe57 SL	226
	227	if (z_len > SSKDF_MAX_INLEN \|\| info_len > SSKDF_MAX_INLEN
	228	\|\| derived_key_len > SSKDF_MAX_INLEN
	229	\|\| derived_key_len == 0)
	230	return 0;
	231
d3386f77 RL	232	*p++ = OSSL_PARAM_construct_octet_string(OSSL_MAC_PARAM_KEY,
	233	(void *)salt, salt_len);
	234	*p = OSSL_PARAM_construct_end();
776796e8 RL	235
776796e8 RL	236	if (!EVP_MAC_CTX_set_params(ctx_init, params))
9537fe57 SL	237	goto end;
	238
	239	if (!kmac_init(ctx_init, kmac_custom, kmac_custom_len, kmac_out_len,
	240	derived_key_len, &kmac_buffer))
	241	goto end;
	242	if (kmac_buffer != NULL)
	243	mac = kmac_buffer;
	244
	245	if (!EVP_MAC_init(ctx_init))
	246	goto end;
	247
	248	out_len = EVP_MAC_size(ctx_init); /* output size */
	249	if (out_len <= 0)
	250	goto end;
	251	len = derived_key_len;
	252
	253	for (counter = 1;; counter++) {
	254	c[0] = (unsigned char)((counter >> 24) & 0xff);
	255	c[1] = (unsigned char)((counter >> 16) & 0xff);
	256	c[2] = (unsigned char)((counter >> 8) & 0xff);
	257	c[3] = (unsigned char)(counter & 0xff);
	258
be5fc053 KR	259	ctx = EVP_MAC_CTX_dup(ctx_init);
be5fc053 KR	260	if (!(ctx != NULL
9537fe57 SL	261	&& EVP_MAC_update(ctx, c, sizeof(c))
	262	&& EVP_MAC_update(ctx, z, z_len)
	263	&& EVP_MAC_update(ctx, info, info_len)))
	264	goto end;
	265	if (len >= out_len) {
776796e8	266	if (!EVP_MAC_final(ctx, out, NULL, len))
9537fe57 SL	267	goto end;
	268	out += out_len;
	269	len -= out_len;
	270	if (len == 0)
	271	break;
	272	} else {
776796e8	273	if (!EVP_MAC_final(ctx, mac, NULL, len))
9537fe57 SL	274	goto end;
	275	memcpy(out, mac, len);
	276	break;
	277	}
be5fc053 KR	278	EVP_MAC_CTX_free(ctx);
be5fc053 KR	279	ctx = NULL;
9537fe57 SL	280	}
	281	ret = 1;
	282	end:
a3c62426 SL	283	if (kmac_buffer != NULL)
	284	OPENSSL_clear_free(kmac_buffer, kmac_out_len);
	285	else
	286	OPENSSL_cleanse(mac_buf, sizeof(mac_buf));
	287
9537fe57	288	EVP_MAC_CTX_free(ctx);
9537fe57 SL	289	return ret;
	290	}
	291
e3405a4a	292	static void sskdf_new(void provctx)
9537fe57	293	{
e3405a4a	294	KDF_SSKDF *ctx;
9537fe57	295
e3405a4a P	296	if ((ctx = OPENSSL_zalloc(sizeof(*ctx))) == NULL)
	297	ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE);
	298	ctx->provctx = provctx;
	299	return ctx;
9537fe57 SL	300	}
9537fe57 SL	301
e3405a4a	302	static void sskdf_reset(void *vctx)
9537fe57	303	{
e3405a4a	304	KDF_SSKDF ctx = (KDF_SSKDF )vctx;
9537fe57	305
d3386f77	306	EVP_MAC_CTX_free(ctx->macctx);
7e149b39	307	ossl_prov_digest_reset(&ctx->digest);
e3405a4a P	308	OPENSSL_clear_free(ctx->secret, ctx->secret_len);
	309	OPENSSL_clear_free(ctx->info, ctx->info_len);
	310	OPENSSL_clear_free(ctx->salt, ctx->salt_len);
e3405a4a	311	memset(ctx, 0, sizeof(*ctx));
9537fe57 SL	312	}
9537fe57 SL	313
e3405a4a	314	static void sskdf_free(void *vctx)
9537fe57	315	{
e3405a4a	316	KDF_SSKDF ctx = (KDF_SSKDF )vctx;
9537fe57	317
e3405a4a	318	sskdf_reset(ctx);
e3405a4a	319	OPENSSL_free(ctx);
9537fe57 SL	320	}
9537fe57 SL	321
e3405a4a P	322	static int sskdf_set_buffer(unsigned char *out, size_t out_len,
e3405a4a P	323	const OSSL_PARAM *p)
9537fe57	324	{
e3405a4a	325	if (p->data == NULL \|\| p->data_size == 0)
9537fe57	326	return 1;
e3405a4a P	327	OPENSSL_free(*out);
	328	*out = NULL;
	329	return OSSL_PARAM_get_octet_string(p, (void **)out, 0, out_len);
9537fe57 SL	330	}
9537fe57 SL	331
e3405a4a	332	static size_t sskdf_size(KDF_SSKDF *ctx)
9537fe57 SL	333	{
9537fe57 SL	334	int len;
7e149b39	335	const EVP_MD *md = ossl_prov_digest_md(&ctx->digest);
9537fe57	336
7e149b39	337	if (md == NULL) {
e3405a4a	338	ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MESSAGE_DIGEST);
9537fe57 SL	339	return 0;
9537fe57 SL	340	}
7e149b39	341	len = EVP_MD_size(md);
9537fe57 SL	342	return (len <= 0) ? 0 : (size_t)len;
	343	}
	344
e3405a4a	345	static int sskdf_derive(void vctx, unsigned char key, size_t keylen)
9537fe57	346	{
e3405a4a	347	KDF_SSKDF ctx = (KDF_SSKDF )vctx;
7e149b39	348	const EVP_MD *md = ossl_prov_digest_md(&ctx->digest);
e3405a4a P	349
	350	if (ctx->secret == NULL) {
	351	ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_SECRET);
9537fe57 SL	352	return 0;
	353	}
	354
d3386f77	355	if (ctx->macctx != NULL) {
9537fe57 SL	356	/* H(x) = KMAC or H(x) = HMAC */
	357	int ret;
	358	const unsigned char *custom = NULL;
	359	size_t custom_len = 0;
9537fe57	360	int default_salt_len;
d3386f77	361	EVP_MAC *mac = EVP_MAC_CTX_mac(ctx->macctx);
9537fe57	362
776796e8 RL	363	/*
	364	* TODO(3.0) investigate the necessity to have all these controls.
	365	* Why does KMAC require a salt length that's shorter than the MD
	366	* block size?
	367	*/
d3386f77	368	if (EVP_MAC_is_a(mac, OSSL_MAC_NAME_HMAC)) {
9537fe57	369	/* H(x) = HMAC(x, salt, hash) */
7e149b39	370	if (md == NULL) {
e3405a4a	371	ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MESSAGE_DIGEST);
9537fe57 SL	372	return 0;
9537fe57 SL	373	}
d3386f77	374	default_salt_len = EVP_MD_size(md);
9537fe57 SL	375	if (default_salt_len <= 0)
9537fe57 SL	376	return 0;
d3386f77 RL	377	} else if (EVP_MAC_is_a(mac, OSSL_MAC_NAME_KMAC128)
d3386f77 RL	378	\|\| EVP_MAC_is_a(mac, OSSL_MAC_NAME_KMAC256)) {
9537fe57 SL	379	/* H(x) = KMACzzz(x, salt, custom) */
	380	custom = kmac_custom_str;
	381	custom_len = sizeof(kmac_custom_str);
d3386f77	382	if (EVP_MAC_is_a(mac, OSSL_MAC_NAME_KMAC128))
9537fe57 SL	383	default_salt_len = SSKDF_KMAC128_DEFAULT_SALT_SIZE;
	384	else
	385	default_salt_len = SSKDF_KMAC256_DEFAULT_SALT_SIZE;
	386	} else {
e3405a4a	387	ERR_raise(ERR_LIB_PROV, PROV_R_UNSUPPORTED_MAC_TYPE);
9537fe57 SL	388	return 0;
	389	}
	390	/* If no salt is set then use a default_salt of zeros */
e3405a4a P	391	if (ctx->salt == NULL \|\| ctx->salt_len <= 0) {
	392	ctx->salt = OPENSSL_zalloc(default_salt_len);
	393	if (ctx->salt == NULL) {
	394	ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE);
9537fe57 SL	395	return 0;
9537fe57 SL	396	}
e3405a4a	397	ctx->salt_len = default_salt_len;
9537fe57	398	}
d3386f77	399	ret = SSKDF_mac_kdm(ctx->macctx,
e3405a4a P	400	custom, custom_len, ctx->out_len,
	401	ctx->salt, ctx->salt_len,
	402	ctx->secret, ctx->secret_len,
	403	ctx->info, ctx->info_len, key, keylen);
9537fe57 SL	404	return ret;
	405	} else {
	406	/* H(x) = hash */
7e149b39	407	if (md == NULL) {
e3405a4a	408	ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MESSAGE_DIGEST);
9537fe57 SL	409	return 0;
9537fe57 SL	410	}
7e149b39	411	return SSKDF_hash_kdm(md, ctx->secret, ctx->secret_len,
e3405a4a	412	ctx->info, ctx->info_len, 0, key, keylen);
8bbeaaa4 SL	413	}
	414	}
	415
e3405a4a	416	static int x963kdf_derive(void vctx, unsigned char key, size_t keylen)
8bbeaaa4	417	{
e3405a4a	418	KDF_SSKDF ctx = (KDF_SSKDF )vctx;
7e149b39	419	const EVP_MD *md = ossl_prov_digest_md(&ctx->digest);
e3405a4a P	420
	421	if (ctx->secret == NULL) {
	422	ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_SECRET);
8bbeaaa4 SL	423	return 0;
	424	}
	425
d3386f77	426	if (ctx->macctx != NULL) {
e3405a4a	427	ERR_raise(ERR_LIB_PROV, PROV_R_NOT_SUPPORTED);
8bbeaaa4	428	return 0;
e3405a4a	429	}
d3386f77 RL	430
	431	/* H(x) = hash */
	432	if (md == NULL) {
	433	ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MESSAGE_DIGEST);
	434	return 0;
	435	}
	436
	437	return SSKDF_hash_kdm(md, ctx->secret, ctx->secret_len,
	438	ctx->info, ctx->info_len, 1, key, keylen);
e3405a4a P	439	}
	440
	441	static int sskdf_set_ctx_params(void *vctx, const OSSL_PARAM params[])
	442	{
	443	const OSSL_PARAM *p;
	444	KDF_SSKDF *ctx = vctx;
d3386f77	445	OPENSSL_CTX *libctx = PROV_LIBRARY_CONTEXT_OF(ctx->provctx);
e3405a4a	446	size_t sz;
e3405a4a	447
d3386f77	448	if (!ossl_prov_digest_load_from_params(&ctx->digest, params, libctx))
7e149b39	449	return 0;
e3405a4a	450
d3386f77 RL	451	if (!ossl_prov_macctx_load_from_params(&ctx->macctx, params,
	452	NULL, NULL, NULL, libctx))
	453	return 0;
e3405a4a P	454
	455	if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SECRET)) != NULL
	456	\|\| (p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_KEY)) != NULL)
	457	if (!sskdf_set_buffer(&ctx->secret, &ctx->secret_len, p))
	458	return 0;
	459
	460	if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_INFO)) != NULL)
	461	if (!sskdf_set_buffer(&ctx->info, &ctx->info_len, p))
	462	return 0;
	463
	464	if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SALT)) != NULL)
	465	if (!sskdf_set_buffer(&ctx->salt, &ctx->salt_len, p))
	466	return 0;
	467
	468	if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_MAC_SIZE))
	469	!= NULL) {
	470	if (!OSSL_PARAM_get_size_t(p, &sz) \|\| sz == 0)
	471	return 0;
	472	ctx->out_len = sz;
9537fe57	473	}
e3405a4a P	474	return 1;
	475	}
	476
	477	static const OSSL_PARAM *sskdf_settable_ctx_params(void)
	478	{
	479	static const OSSL_PARAM known_settable_ctx_params[] = {
	480	OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SECRET, NULL, 0),
	481	OSSL_PARAM_octet_string(OSSL_KDF_PARAM_KEY, NULL, 0),
	482	OSSL_PARAM_octet_string(OSSL_KDF_PARAM_INFO, NULL, 0),
	483	OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_PROPERTIES, NULL, 0),
	484	OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_DIGEST, NULL, 0),
	485	OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_MAC, NULL, 0),
	486	OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SALT, NULL, 0),
	487	OSSL_PARAM_size_t(OSSL_KDF_PARAM_MAC_SIZE, NULL),
	488	OSSL_PARAM_END
	489	};
	490	return known_settable_ctx_params;
	491	}
	492
	493	static int sskdf_get_ctx_params(void *vctx, OSSL_PARAM params[])
	494	{
	495	KDF_SSKDF ctx = (KDF_SSKDF )vctx;
	496	OSSL_PARAM *p;
	497
	498	if ((p = OSSL_PARAM_locate(params, OSSL_KDF_PARAM_SIZE)) != NULL)
	499	return OSSL_PARAM_set_size_t(p, sskdf_size(ctx));
	500	return -2;
	501	}
	502
	503	static const OSSL_PARAM *sskdf_gettable_ctx_params(void)
	504	{
	505	static const OSSL_PARAM known_gettable_ctx_params[] = {
	506	OSSL_PARAM_size_t(OSSL_KDF_PARAM_SIZE, NULL),
	507	OSSL_PARAM_END
	508	};
	509	return known_gettable_ctx_params;
9537fe57 SL	510	}
9537fe57 SL	511
e3405a4a P	512	const OSSL_DISPATCH kdf_sskdf_functions[] = {
	513	{ OSSL_FUNC_KDF_NEWCTX, (void(*)(void))sskdf_new },
	514	{ OSSL_FUNC_KDF_FREECTX, (void(*)(void))sskdf_free },
	515	{ OSSL_FUNC_KDF_RESET, (void(*)(void))sskdf_reset },
	516	{ OSSL_FUNC_KDF_DERIVE, (void(*)(void))sskdf_derive },
	517	{ OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS,
	518	(void(*)(void))sskdf_settable_ctx_params },
	519	{ OSSL_FUNC_KDF_SET_CTX_PARAMS, (void(*)(void))sskdf_set_ctx_params },
	520	{ OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS,
	521	(void(*)(void))sskdf_gettable_ctx_params },
	522	{ OSSL_FUNC_KDF_GET_CTX_PARAMS, (void(*)(void))sskdf_get_ctx_params },
	523	{ 0, NULL }
9537fe57	524	};
8bbeaaa4	525
e3405a4a P	526	const OSSL_DISPATCH kdf_x963_kdf_functions[] = {
	527	{ OSSL_FUNC_KDF_NEWCTX, (void(*)(void))sskdf_new },
	528	{ OSSL_FUNC_KDF_FREECTX, (void(*)(void))sskdf_free },
	529	{ OSSL_FUNC_KDF_RESET, (void(*)(void))sskdf_reset },
	530	{ OSSL_FUNC_KDF_DERIVE, (void(*)(void))x963kdf_derive },
	531	{ OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS,
	532	(void(*)(void))sskdf_settable_ctx_params },
	533	{ OSSL_FUNC_KDF_SET_CTX_PARAMS, (void(*)(void))sskdf_set_ctx_params },
	534	{ OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS,
	535	(void(*)(void))sskdf_gettable_ctx_params },
	536	{ OSSL_FUNC_KDF_GET_CTX_PARAMS, (void(*)(void))sskdf_get_ctx_params },
	537	{ 0, NULL }
8bbeaaa4	538	};