[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"

typedef struct {
    void *provctx;
    EVP_MAC *mac;       /* H(x) = HMAC_hash OR H(x) = KMAC */
    EVP_MD *md;         /* H(x) = hash OR when H(x) = HMAC_hash */
    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 *kdf_mac, const EVP_MD *hmac_md,
                         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, *ctx_init = NULL;
    unsigned char *mac = mac_buf, *kmac_buffer = NULL;
    OSSL_PARAM params[3];
    size_t params_n = 0;

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

    ctx_init = EVP_MAC_CTX_new(kdf_mac);
    if (ctx_init == NULL)
        goto end;

    if (hmac_md != NULL) {
        const char *mdname = EVP_MD_name(hmac_md);
        params[params_n++] =
            OSSL_PARAM_construct_utf8_string(OSSL_MAC_PARAM_DIGEST,
                                             (char *)mdname, 0);
    }
    params[params_n++] =
        OSSL_PARAM_construct_octet_string(OSSL_MAC_PARAM_KEY, (void *)salt,
                                          salt_len);
    params[params_n] = 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);
    EVP_MAC_CTX_free(ctx_init);
    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;

    OPENSSL_clear_free(ctx->secret, ctx->secret_len);
    OPENSSL_clear_free(ctx->info, ctx->info_len);
    OPENSSL_clear_free(ctx->salt, ctx->salt_len);
    EVP_MAC_free(ctx->mac);
    memset(ctx, 0, sizeof(*ctx));
}

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

    sskdf_reset(ctx);
    EVP_MD_meth_free(ctx->md);
    EVP_MAC_free(ctx->mac);
    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;

    if (ctx->md == NULL) {
        ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MESSAGE_DIGEST);
        return 0;
    }
    len = EVP_MD_size(ctx->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;

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

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

        /*
         * 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?
         */
        macname = EVP_MAC_name(ctx->mac);
        if (strcmp(macname, OSSL_MAC_NAME_HMAC) == 0) {
            /* H(x) = HMAC(x, salt, hash) */
            if (ctx->md == NULL) {
                ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MESSAGE_DIGEST);
                return 0;
            }
            default_salt_len = EVP_MD_block_size(ctx->md);
            if (default_salt_len <= 0)
                return 0;
        } else if (strcmp(macname, OSSL_MAC_NAME_KMAC128) == 0
                   || strcmp(macname, OSSL_MAC_NAME_KMAC256) == 0) {
            /* H(x) = KMACzzz(x, salt, custom) */
            custom = kmac_custom_str;
            custom_len = sizeof(kmac_custom_str);
            if (strcmp(macname, OSSL_MAC_NAME_KMAC128) == 0)
                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->mac, ctx->md,
                            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 (ctx->md == NULL) {
            ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MESSAGE_DIGEST);
            return 0;
        }
        return SSKDF_hash_kdm(ctx->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;

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

    if (ctx->mac != NULL) {
        ERR_raise(ERR_LIB_PROV, PROV_R_NOT_SUPPORTED);
        return 0;
    } else {
        /* H(x) = hash */
        if (ctx->md == NULL) {
            ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MESSAGE_DIGEST);
            return 0;
        }
        return SSKDF_hash_kdm(ctx->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;
    EVP_MD *md;
    EVP_MAC *mac;
    size_t sz;
    const char *properties = NULL;

    /* Grab search properties, should be before the digest and mac lookups */
    if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_PROPERTIES))
        != NULL) {
        if (p->data_type != OSSL_PARAM_UTF8_STRING)
            return 0;
        properties = p->data;
    }
    /* Handle aliasing of digest parameter names */
    if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_DIGEST)) != NULL) {
        if (p->data_type != OSSL_PARAM_UTF8_STRING)
            return 0;
        md = EVP_MD_fetch(PROV_LIBRARY_CONTEXT_OF(ctx->provctx), p->data,
                          properties);
        if (md == NULL) {
            ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_DIGEST);
            return 0;
        }
        EVP_MD_meth_free(ctx->md);
        ctx->md = md;
    }

    if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_MAC)) != NULL) {
        EVP_MAC_free(ctx->mac);
        ctx->mac = NULL;

        mac = EVP_MAC_fetch(PROV_LIBRARY_CONTEXT_OF(ctx->provctx), p->data,
                            properties);
        if (mac == NULL)
            return 0;
        EVP_MAC_free(ctx->mac);
        ctx->mac = mac;
    }

    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"
9537fe57	51
e3405a4a P	52	typedef struct {
e3405a4a P	53	void *provctx;
776796e8	54	EVP_MAC mac; / H(x) = HMAC_hash OR H(x) = KMAC */
e3405a4a	55	EVP_MD md; / H(x) = hash OR when H(x) = HMAC_hash */
9537fe57 SL	56	unsigned char *secret;
	57	size_t secret_len;
	58	unsigned char *info;
	59	size_t info_len;
	60	unsigned char *salt;
	61	size_t salt_len;
	62	size_t out_len; /* optional KMAC parameter */
e3405a4a	63	} KDF_SSKDF;
9537fe57 SL	64
	65	#define SSKDF_MAX_INLEN (1<<30)
	66	#define SSKDF_KMAC128_DEFAULT_SALT_SIZE (168 - 4)
	67	#define SSKDF_KMAC256_DEFAULT_SALT_SIZE (136 - 4)
	68
	69	/* KMAC uses a Customisation string of 'KDF' */
	70	static const unsigned char kmac_custom_str[] = { 0x4B, 0x44, 0x46 };
	71
e3405a4a P	72	static OSSL_OP_kdf_newctx_fn sskdf_new;
	73	static OSSL_OP_kdf_freectx_fn sskdf_free;
	74	static OSSL_OP_kdf_reset_fn sskdf_reset;
	75	static OSSL_OP_kdf_derive_fn sskdf_derive;
	76	static OSSL_OP_kdf_derive_fn x963kdf_derive;
	77	static OSSL_OP_kdf_settable_ctx_params_fn sskdf_settable_ctx_params;
	78	static OSSL_OP_kdf_set_ctx_params_fn sskdf_set_ctx_params;
	79	static OSSL_OP_kdf_gettable_ctx_params_fn sskdf_gettable_ctx_params;
	80	static OSSL_OP_kdf_get_ctx_params_fn sskdf_get_ctx_params;
	81
9537fe57 SL	82	/*
	83	* Refer to https://csrc.nist.gov/publications/detail/sp/800-56c/rev-1/final
	84	* Section 4. One-Step Key Derivation using H(x) = hash(x)
8bbeaaa4 SL	85	* Note: X9.63 also uses this code with the only difference being that the
	86	* counter is appended to the secret 'z'.
	87	* i.e.
	88	* result[i] = Hash(counter \|\| z \|\| info) for One Step OR
	89	* result[i] = Hash(z \|\| counter \|\| info) for X9.63.
9537fe57 SL	90	*/
	91	static int SSKDF_hash_kdm(const EVP_MD *kdf_md,
	92	const unsigned char *z, size_t z_len,
	93	const unsigned char *info, size_t info_len,
8bbeaaa4	94	unsigned int append_ctr,
9537fe57 SL	95	unsigned char *derived_key, size_t derived_key_len)
	96	{
	97	int ret = 0, hlen;
	98	size_t counter, out_len, len = derived_key_len;
	99	unsigned char c[4];
	100	unsigned char mac[EVP_MAX_MD_SIZE];
	101	unsigned char *out = derived_key;
	102	EVP_MD_CTX ctx = NULL, ctx_init = NULL;
	103
	104	if (z_len > SSKDF_MAX_INLEN \|\| info_len > SSKDF_MAX_INLEN
	105	\|\| derived_key_len > SSKDF_MAX_INLEN
	106	\|\| derived_key_len == 0)
	107	return 0;
	108
	109	hlen = EVP_MD_size(kdf_md);
	110	if (hlen <= 0)
	111	return 0;
	112	out_len = (size_t)hlen;
	113
	114	ctx = EVP_MD_CTX_create();
	115	ctx_init = EVP_MD_CTX_create();
	116	if (ctx == NULL \|\| ctx_init == NULL)
	117	goto end;
	118
	119	if (!EVP_DigestInit(ctx_init, kdf_md))
	120	goto end;
	121
	122	for (counter = 1;; counter++) {
	123	c[0] = (unsigned char)((counter >> 24) & 0xff);
	124	c[1] = (unsigned char)((counter >> 16) & 0xff);
	125	c[2] = (unsigned char)((counter >> 8) & 0xff);
	126	c[3] = (unsigned char)(counter & 0xff);
	127
	128	if (!(EVP_MD_CTX_copy_ex(ctx, ctx_init)
8bbeaaa4	129	&& (append_ctr \|\| EVP_DigestUpdate(ctx, c, sizeof(c)))
9537fe57	130	&& EVP_DigestUpdate(ctx, z, z_len)
8bbeaaa4	131	&& (!append_ctr \|\| EVP_DigestUpdate(ctx, c, sizeof(c)))
9537fe57 SL	132	&& EVP_DigestUpdate(ctx, info, info_len)))
	133	goto end;
	134	if (len >= out_len) {
	135	if (!EVP_DigestFinal_ex(ctx, out, NULL))
	136	goto end;
	137	out += out_len;
	138	len -= out_len;
	139	if (len == 0)
	140	break;
	141	} else {
	142	if (!EVP_DigestFinal_ex(ctx, mac, NULL))
	143	goto end;
	144	memcpy(out, mac, len);
	145	break;
	146	}
	147	}
	148	ret = 1;
	149	end:
	150	EVP_MD_CTX_destroy(ctx);
	151	EVP_MD_CTX_destroy(ctx_init);
	152	OPENSSL_cleanse(mac, sizeof(mac));
	153	return ret;
	154	}
	155
	156	static int kmac_init(EVP_MAC_CTX ctx, const unsigned char custom,
	157	size_t custom_len, size_t kmac_out_len,
	158	size_t derived_key_len, unsigned char **out)
	159	{
776796e8 RL	160	OSSL_PARAM params[2];
776796e8 RL	161
9537fe57 SL	162	/* Only KMAC has custom data - so return if not KMAC */
	163	if (custom == NULL)
	164	return 1;
	165
776796e8 RL	166	params[0] = OSSL_PARAM_construct_octet_string(OSSL_MAC_PARAM_CUSTOM,
	167	(void *)custom, custom_len);
	168	params[1] = OSSL_PARAM_construct_end();
	169
	170	if (!EVP_MAC_CTX_set_params(ctx, params))
9537fe57 SL	171	return 0;
	172
	173	/* By default only do one iteration if kmac_out_len is not specified */
	174	if (kmac_out_len == 0)
	175	kmac_out_len = derived_key_len;
	176	/* otherwise check the size is valid */
	177	else if (!(kmac_out_len == derived_key_len
	178	\|\| kmac_out_len == 20
	179	\|\| kmac_out_len == 28
	180	\|\| kmac_out_len == 32
	181	\|\| kmac_out_len == 48
	182	\|\| kmac_out_len == 64))
	183	return 0;
	184
703170d4	185	params[0] = OSSL_PARAM_construct_size_t(OSSL_MAC_PARAM_SIZE,
776796e8 RL	186	&kmac_out_len);
	187
	188	if (EVP_MAC_CTX_set_params(ctx, params) <= 0)
9537fe57 SL	189	return 0;
	190
	191	/*
	192	* For kmac the output buffer can be larger than EVP_MAX_MD_SIZE: so
	193	* alloc a buffer for this case.
	194	*/
	195	if (kmac_out_len > EVP_MAX_MD_SIZE) {
	196	*out = OPENSSL_zalloc(kmac_out_len);
	197	if (*out == NULL)
	198	return 0;
	199	}
	200	return 1;
	201	}
	202
	203	/*
	204	* Refer to https://csrc.nist.gov/publications/detail/sp/800-56c/rev-1/final
	205	* Section 4. One-Step Key Derivation using MAC: i.e either
	206	* H(x) = HMAC-hash(salt, x) OR
	207	* H(x) = KMAC#(salt, x, outbits, CustomString='KDF')
	208	*/
776796e8	209	static int SSKDF_mac_kdm(EVP_MAC kdf_mac, const EVP_MD hmac_md,
9537fe57 SL	210	const unsigned char *kmac_custom,
	211	size_t kmac_custom_len, size_t kmac_out_len,
	212	const unsigned char *salt, size_t salt_len,
	213	const unsigned char *z, size_t z_len,
	214	const unsigned char *info, size_t info_len,
	215	unsigned char *derived_key, size_t derived_key_len)
	216	{
	217	int ret = 0;
	218	size_t counter, out_len, len;
	219	unsigned char c[4];
	220	unsigned char mac_buf[EVP_MAX_MD_SIZE];
	221	unsigned char *out = derived_key;
	222	EVP_MAC_CTX ctx = NULL, ctx_init = NULL;
	223	unsigned char mac = mac_buf, kmac_buffer = NULL;
776796e8 RL	224	OSSL_PARAM params[3];
776796e8 RL	225	size_t params_n = 0;
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
9537fe57	232	ctx_init = EVP_MAC_CTX_new(kdf_mac);
be5fc053	233	if (ctx_init == NULL)
9537fe57	234	goto end;
9537fe57	235
776796e8 RL	236	if (hmac_md != NULL) {
	237	const char *mdname = EVP_MD_name(hmac_md);
	238	params[params_n++] =
703170d4	239	OSSL_PARAM_construct_utf8_string(OSSL_MAC_PARAM_DIGEST,
7f588d20	240	(char *)mdname, 0);
776796e8 RL	241	}
	242	params[params_n++] =
	243	OSSL_PARAM_construct_octet_string(OSSL_MAC_PARAM_KEY, (void *)salt,
	244	salt_len);
	245	params[params_n] = OSSL_PARAM_construct_end();
	246
	247	if (!EVP_MAC_CTX_set_params(ctx_init, params))
9537fe57 SL	248	goto end;
	249
	250	if (!kmac_init(ctx_init, kmac_custom, kmac_custom_len, kmac_out_len,
	251	derived_key_len, &kmac_buffer))
	252	goto end;
	253	if (kmac_buffer != NULL)
	254	mac = kmac_buffer;
	255
	256	if (!EVP_MAC_init(ctx_init))
	257	goto end;
	258
	259	out_len = EVP_MAC_size(ctx_init); /* output size */
	260	if (out_len <= 0)
	261	goto end;
	262	len = derived_key_len;
	263
	264	for (counter = 1;; counter++) {
	265	c[0] = (unsigned char)((counter >> 24) & 0xff);
	266	c[1] = (unsigned char)((counter >> 16) & 0xff);
	267	c[2] = (unsigned char)((counter >> 8) & 0xff);
	268	c[3] = (unsigned char)(counter & 0xff);
	269
be5fc053 KR	270	ctx = EVP_MAC_CTX_dup(ctx_init);
be5fc053 KR	271	if (!(ctx != NULL
9537fe57 SL	272	&& EVP_MAC_update(ctx, c, sizeof(c))
	273	&& EVP_MAC_update(ctx, z, z_len)
	274	&& EVP_MAC_update(ctx, info, info_len)))
	275	goto end;
	276	if (len >= out_len) {
776796e8	277	if (!EVP_MAC_final(ctx, out, NULL, len))
9537fe57 SL	278	goto end;
	279	out += out_len;
	280	len -= out_len;
	281	if (len == 0)
	282	break;
	283	} else {
776796e8	284	if (!EVP_MAC_final(ctx, mac, NULL, len))
9537fe57 SL	285	goto end;
	286	memcpy(out, mac, len);
	287	break;
	288	}
be5fc053 KR	289	EVP_MAC_CTX_free(ctx);
be5fc053 KR	290	ctx = NULL;
9537fe57 SL	291	}
	292	ret = 1;
	293	end:
a3c62426 SL	294	if (kmac_buffer != NULL)
	295	OPENSSL_clear_free(kmac_buffer, kmac_out_len);
	296	else
	297	OPENSSL_cleanse(mac_buf, sizeof(mac_buf));
	298
9537fe57 SL	299	EVP_MAC_CTX_free(ctx);
9537fe57 SL	300	EVP_MAC_CTX_free(ctx_init);
9537fe57 SL	301	return ret;
	302	}
	303
e3405a4a	304	static void sskdf_new(void provctx)
9537fe57	305	{
e3405a4a	306	KDF_SSKDF *ctx;
9537fe57	307
e3405a4a P	308	if ((ctx = OPENSSL_zalloc(sizeof(*ctx))) == NULL)
	309	ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE);
	310	ctx->provctx = provctx;
	311	return ctx;
9537fe57 SL	312	}
9537fe57 SL	313
e3405a4a	314	static void sskdf_reset(void *vctx)
9537fe57	315	{
e3405a4a	316	KDF_SSKDF ctx = (KDF_SSKDF )vctx;
9537fe57	317
e3405a4a P	318	OPENSSL_clear_free(ctx->secret, ctx->secret_len);
	319	OPENSSL_clear_free(ctx->info, ctx->info_len);
	320	OPENSSL_clear_free(ctx->salt, ctx->salt_len);
	321	EVP_MAC_free(ctx->mac);
	322	memset(ctx, 0, sizeof(*ctx));
9537fe57 SL	323	}
9537fe57 SL	324
e3405a4a	325	static void sskdf_free(void *vctx)
9537fe57	326	{
e3405a4a	327	KDF_SSKDF ctx = (KDF_SSKDF )vctx;
9537fe57	328
e3405a4a P	329	sskdf_reset(ctx);
	330	EVP_MD_meth_free(ctx->md);
	331	EVP_MAC_free(ctx->mac);
	332	OPENSSL_free(ctx);
9537fe57 SL	333	}
9537fe57 SL	334
e3405a4a P	335	static int sskdf_set_buffer(unsigned char *out, size_t out_len,
e3405a4a P	336	const OSSL_PARAM *p)
9537fe57	337	{
e3405a4a	338	if (p->data == NULL \|\| p->data_size == 0)
9537fe57	339	return 1;
e3405a4a P	340	OPENSSL_free(*out);
	341	*out = NULL;
	342	return OSSL_PARAM_get_octet_string(p, (void **)out, 0, out_len);
9537fe57 SL	343	}
9537fe57 SL	344
e3405a4a	345	static size_t sskdf_size(KDF_SSKDF *ctx)
9537fe57 SL	346	{
	347	int len;
	348
e3405a4a P	349	if (ctx->md == NULL) {
e3405a4a P	350	ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MESSAGE_DIGEST);
9537fe57 SL	351	return 0;
9537fe57 SL	352	}
e3405a4a	353	len = EVP_MD_size(ctx->md);
9537fe57 SL	354	return (len <= 0) ? 0 : (size_t)len;
	355	}
	356
e3405a4a	357	static int sskdf_derive(void vctx, unsigned char key, size_t keylen)
9537fe57	358	{
e3405a4a P	359	KDF_SSKDF ctx = (KDF_SSKDF )vctx;
	360
	361	if (ctx->secret == NULL) {
	362	ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_SECRET);
9537fe57 SL	363	return 0;
	364	}
	365
e3405a4a	366	if (ctx->mac != NULL) {
9537fe57 SL	367	/* H(x) = KMAC or H(x) = HMAC */
	368	int ret;
	369	const unsigned char *custom = NULL;
	370	size_t custom_len = 0;
776796e8	371	const char *macname;
9537fe57 SL	372	int default_salt_len;
9537fe57 SL	373
776796e8 RL	374	/*
	375	* TODO(3.0) investigate the necessity to have all these controls.
	376	* Why does KMAC require a salt length that's shorter than the MD
	377	* block size?
	378	*/
e3405a4a	379	macname = EVP_MAC_name(ctx->mac);
81ff9eeb	380	if (strcmp(macname, OSSL_MAC_NAME_HMAC) == 0) {
9537fe57	381	/* H(x) = HMAC(x, salt, hash) */
e3405a4a P	382	if (ctx->md == NULL) {
e3405a4a P	383	ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MESSAGE_DIGEST);
9537fe57 SL	384	return 0;
9537fe57 SL	385	}
e3405a4a	386	default_salt_len = EVP_MD_block_size(ctx->md);
9537fe57 SL	387	if (default_salt_len <= 0)
9537fe57 SL	388	return 0;
81ff9eeb RL	389	} else if (strcmp(macname, OSSL_MAC_NAME_KMAC128) == 0
81ff9eeb RL	390	\|\| strcmp(macname, OSSL_MAC_NAME_KMAC256) == 0) {
9537fe57 SL	391	/* H(x) = KMACzzz(x, salt, custom) */
	392	custom = kmac_custom_str;
	393	custom_len = sizeof(kmac_custom_str);
81ff9eeb	394	if (strcmp(macname, OSSL_MAC_NAME_KMAC128) == 0)
9537fe57 SL	395	default_salt_len = SSKDF_KMAC128_DEFAULT_SALT_SIZE;
	396	else
	397	default_salt_len = SSKDF_KMAC256_DEFAULT_SALT_SIZE;
	398	} else {
e3405a4a	399	ERR_raise(ERR_LIB_PROV, PROV_R_UNSUPPORTED_MAC_TYPE);
9537fe57 SL	400	return 0;
	401	}
	402	/* If no salt is set then use a default_salt of zeros */
e3405a4a P	403	if (ctx->salt == NULL \|\| ctx->salt_len <= 0) {
	404	ctx->salt = OPENSSL_zalloc(default_salt_len);
	405	if (ctx->salt == NULL) {
	406	ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE);
9537fe57 SL	407	return 0;
9537fe57 SL	408	}
e3405a4a	409	ctx->salt_len = default_salt_len;
9537fe57	410	}
e3405a4a P	411	ret = SSKDF_mac_kdm(ctx->mac, ctx->md,
	412	custom, custom_len, ctx->out_len,
	413	ctx->salt, ctx->salt_len,
	414	ctx->secret, ctx->secret_len,
	415	ctx->info, ctx->info_len, key, keylen);
9537fe57 SL	416	return ret;
	417	} else {
	418	/* H(x) = hash */
e3405a4a P	419	if (ctx->md == NULL) {
e3405a4a P	420	ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MESSAGE_DIGEST);
9537fe57 SL	421	return 0;
9537fe57 SL	422	}
e3405a4a P	423	return SSKDF_hash_kdm(ctx->md, ctx->secret, ctx->secret_len,
e3405a4a P	424	ctx->info, ctx->info_len, 0, key, keylen);
8bbeaaa4 SL	425	}
	426	}
	427
e3405a4a	428	static int x963kdf_derive(void vctx, unsigned char key, size_t keylen)
8bbeaaa4	429	{
e3405a4a P	430	KDF_SSKDF ctx = (KDF_SSKDF )vctx;
	431
	432	if (ctx->secret == NULL) {
	433	ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_SECRET);
8bbeaaa4 SL	434	return 0;
	435	}
	436
e3405a4a P	437	if (ctx->mac != NULL) {
e3405a4a P	438	ERR_raise(ERR_LIB_PROV, PROV_R_NOT_SUPPORTED);
8bbeaaa4 SL	439	return 0;
	440	} else {
	441	/* H(x) = hash */
e3405a4a P	442	if (ctx->md == NULL) {
	443	ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MESSAGE_DIGEST);
	444	return 0;
	445	}
	446	return SSKDF_hash_kdm(ctx->md, ctx->secret, ctx->secret_len,
	447	ctx->info, ctx->info_len, 1, key, keylen);
	448	}
	449	}
	450
	451	static int sskdf_set_ctx_params(void *vctx, const OSSL_PARAM params[])
	452	{
	453	const OSSL_PARAM *p;
	454	KDF_SSKDF *ctx = vctx;
	455	EVP_MD *md;
	456	EVP_MAC *mac;
	457	size_t sz;
	458	const char *properties = NULL;
	459
	460	/* Grab search properties, should be before the digest and mac lookups */
	461	if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_PROPERTIES))
	462	!= NULL) {
	463	if (p->data_type != OSSL_PARAM_UTF8_STRING)
	464	return 0;
	465	properties = p->data;
	466	}
	467	/* Handle aliasing of digest parameter names */
	468	if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_DIGEST)) != NULL) {
	469	if (p->data_type != OSSL_PARAM_UTF8_STRING)
	470	return 0;
	471	md = EVP_MD_fetch(PROV_LIBRARY_CONTEXT_OF(ctx->provctx), p->data,
	472	properties);
	473	if (md == NULL) {
	474	ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_DIGEST);
8bbeaaa4 SL	475	return 0;
8bbeaaa4 SL	476	}
e3405a4a P	477	EVP_MD_meth_free(ctx->md);
	478	ctx->md = md;
	479	}
	480
	481	if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_MAC)) != NULL) {
	482	EVP_MAC_free(ctx->mac);
	483	ctx->mac = NULL;
	484
	485	mac = EVP_MAC_fetch(PROV_LIBRARY_CONTEXT_OF(ctx->provctx), p->data,
	486	properties);
	487	if (mac == NULL)
	488	return 0;
	489	EVP_MAC_free(ctx->mac);
	490	ctx->mac = mac;
	491	}
	492
	493	if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SECRET)) != NULL
	494	\|\| (p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_KEY)) != NULL)
	495	if (!sskdf_set_buffer(&ctx->secret, &ctx->secret_len, p))
	496	return 0;
	497
	498	if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_INFO)) != NULL)
	499	if (!sskdf_set_buffer(&ctx->info, &ctx->info_len, p))
	500	return 0;
	501
	502	if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SALT)) != NULL)
	503	if (!sskdf_set_buffer(&ctx->salt, &ctx->salt_len, p))
	504	return 0;
	505
	506	if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_MAC_SIZE))
	507	!= NULL) {
	508	if (!OSSL_PARAM_get_size_t(p, &sz) \|\| sz == 0)
	509	return 0;
	510	ctx->out_len = sz;
9537fe57	511	}
e3405a4a P	512	return 1;
	513	}
	514
	515	static const OSSL_PARAM *sskdf_settable_ctx_params(void)
	516	{
	517	static const OSSL_PARAM known_settable_ctx_params[] = {
	518	OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SECRET, NULL, 0),
	519	OSSL_PARAM_octet_string(OSSL_KDF_PARAM_KEY, NULL, 0),
	520	OSSL_PARAM_octet_string(OSSL_KDF_PARAM_INFO, NULL, 0),
	521	OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_PROPERTIES, NULL, 0),
	522	OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_DIGEST, NULL, 0),
	523	OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_MAC, NULL, 0),
	524	OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SALT, NULL, 0),
	525	OSSL_PARAM_size_t(OSSL_KDF_PARAM_MAC_SIZE, NULL),
	526	OSSL_PARAM_END
	527	};
	528	return known_settable_ctx_params;
	529	}
	530
	531	static int sskdf_get_ctx_params(void *vctx, OSSL_PARAM params[])
	532	{
	533	KDF_SSKDF ctx = (KDF_SSKDF )vctx;
	534	OSSL_PARAM *p;
	535
	536	if ((p = OSSL_PARAM_locate(params, OSSL_KDF_PARAM_SIZE)) != NULL)
	537	return OSSL_PARAM_set_size_t(p, sskdf_size(ctx));
	538	return -2;
	539	}
	540
	541	static const OSSL_PARAM *sskdf_gettable_ctx_params(void)
	542	{
	543	static const OSSL_PARAM known_gettable_ctx_params[] = {
	544	OSSL_PARAM_size_t(OSSL_KDF_PARAM_SIZE, NULL),
	545	OSSL_PARAM_END
	546	};
	547	return known_gettable_ctx_params;
9537fe57 SL	548	}
9537fe57 SL	549
e3405a4a P	550	const OSSL_DISPATCH kdf_sskdf_functions[] = {
	551	{ OSSL_FUNC_KDF_NEWCTX, (void(*)(void))sskdf_new },
	552	{ OSSL_FUNC_KDF_FREECTX, (void(*)(void))sskdf_free },
	553	{ OSSL_FUNC_KDF_RESET, (void(*)(void))sskdf_reset },
	554	{ OSSL_FUNC_KDF_DERIVE, (void(*)(void))sskdf_derive },
	555	{ OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS,
	556	(void(*)(void))sskdf_settable_ctx_params },
	557	{ OSSL_FUNC_KDF_SET_CTX_PARAMS, (void(*)(void))sskdf_set_ctx_params },
	558	{ OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS,
	559	(void(*)(void))sskdf_gettable_ctx_params },
	560	{ OSSL_FUNC_KDF_GET_CTX_PARAMS, (void(*)(void))sskdf_get_ctx_params },
	561	{ 0, NULL }
9537fe57	562	};
8bbeaaa4	563
e3405a4a P	564	const OSSL_DISPATCH kdf_x963_kdf_functions[] = {
	565	{ OSSL_FUNC_KDF_NEWCTX, (void(*)(void))sskdf_new },
	566	{ OSSL_FUNC_KDF_FREECTX, (void(*)(void))sskdf_free },
	567	{ OSSL_FUNC_KDF_RESET, (void(*)(void))sskdf_reset },
	568	{ OSSL_FUNC_KDF_DERIVE, (void(*)(void))x963kdf_derive },
	569	{ OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS,
	570	(void(*)(void))sskdf_settable_ctx_params },
	571	{ OSSL_FUNC_KDF_SET_CTX_PARAMS, (void(*)(void))sskdf_set_ctx_params },
	572	{ OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS,
	573	(void(*)(void))sskdf_gettable_ctx_params },
	574	{ OSSL_FUNC_KDF_GET_CTX_PARAMS, (void(*)(void))sskdf_get_ctx_params },
	575	{ 0, NULL }
8bbeaaa4	576	};