/src/openssl31/providers/implementations/kdfs/kbkdf.c

Source (jump to first uncovered line)
/*
 * Copyright 2019-2024 The OpenSSL Project Authors. All Rights Reserved.
 * Copyright 2019 Red Hat, Inc.
 *
 * 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
 */

/*
 * This implements https://csrc.nist.gov/publications/detail/sp/800-108/final
 * section 5.1 ("counter mode") and section 5.2 ("feedback mode") in both HMAC
 * and CMAC.  That document does not name the KDFs it defines; the name is
 * derived from
 * https://csrc.nist.gov/Projects/Cryptographic-Algorithm-Validation-Program/Key-Derivation
 *
 * Note that section 5.3 ("double-pipeline mode") is not implemented, though
 * it would be possible to do so in the future.
 *
 * These versions all assume the counter is used.  It would be relatively
 * straightforward to expose a configuration handle should the need arise.
 *
 * Variable names attempt to match those of SP800-108.
 */

#include <stdarg.h>
#include <stdlib.h>
#include <string.h>

#include <openssl/core_names.h>
#include <openssl/evp.h>
#include <openssl/hmac.h>
#include <openssl/kdf.h>
#include <openssl/params.h>
#include <openssl/proverr.h>

#include "internal/cryptlib.h"
#include "crypto/evp.h"
#include "internal/numbers.h"
#include "internal/endian.h"
#include "prov/implementations.h"
#include "prov/provider_ctx.h"
#include "prov/provider_util.h"
#include "prov/providercommon.h"

#include "internal/e_os.h"

#define ossl_min(a, b) ((a) < (b)) ? (a) : (b)

typedef enum {
    COUNTER = 0,
    FEEDBACK
} kbkdf_mode;

/* Our context structure. */
typedef struct {
    void *provctx;
    kbkdf_mode mode;
    EVP_MAC_CTX *ctx_init;

    /* Names are lowercased versions of those found in SP800-108. */
    int r;
    unsigned char *ki;
    size_t ki_len;
    unsigned char *label;
    size_t label_len;
    unsigned char *context;
    size_t context_len;
    unsigned char *iv;
    size_t iv_len;
    int use_l;
    int is_kmac;
    int use_separator;
} KBKDF;

/* Definitions needed for typechecking. */
static OSSL_FUNC_kdf_newctx_fn kbkdf_new;
static OSSL_FUNC_kdf_dupctx_fn kbkdf_dup;
static OSSL_FUNC_kdf_freectx_fn kbkdf_free;
static OSSL_FUNC_kdf_reset_fn kbkdf_reset;
static OSSL_FUNC_kdf_derive_fn kbkdf_derive;
static OSSL_FUNC_kdf_settable_ctx_params_fn kbkdf_settable_ctx_params;
static OSSL_FUNC_kdf_set_ctx_params_fn kbkdf_set_ctx_params;
static OSSL_FUNC_kdf_gettable_ctx_params_fn kbkdf_gettable_ctx_params;
static OSSL_FUNC_kdf_get_ctx_params_fn kbkdf_get_ctx_params;

/* Not all platforms have htobe32(). */
static uint32_t be32(uint32_t host)
{
    uint32_t big = 0;
    DECLARE_IS_ENDIAN;

    if (!IS_LITTLE_ENDIAN)
        return host;

    big |= (host & 0xff000000) >> 24;
    big |= (host & 0x00ff0000) >> 8;
    big |= (host & 0x0000ff00) << 8;
    big |= (host & 0x000000ff) << 24;
    return big;
}

static void init(KBKDF *ctx)
{
    ctx->r = 32;
    ctx->use_l = 1;
    ctx->use_separator = 1;
    ctx->is_kmac = 0;
}

static void *kbkdf_new(void *provctx)
{
    KBKDF *ctx;

    if (!ossl_prov_is_running())
        return NULL;

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

    ctx->provctx = provctx;
    init(ctx);
    return ctx;
}

static void kbkdf_free(void *vctx)
{
    KBKDF *ctx = (KBKDF *)vctx;

    if (ctx != NULL) {
        kbkdf_reset(ctx);
        OPENSSL_free(ctx);
    }
}

static void kbkdf_reset(void *vctx)
{
    KBKDF *ctx = (KBKDF *)vctx;
    void *provctx = ctx->provctx;

    EVP_MAC_CTX_free(ctx->ctx_init);
    OPENSSL_clear_free(ctx->context, ctx->context_len);
    OPENSSL_clear_free(ctx->label, ctx->label_len);
    OPENSSL_clear_free(ctx->ki, ctx->ki_len);
    OPENSSL_clear_free(ctx->iv, ctx->iv_len);
    memset(ctx, 0, sizeof(*ctx));
    ctx->provctx = provctx;
    init(ctx);
}

static void *kbkdf_dup(void *vctx)
{
    const KBKDF *src = (const KBKDF *)vctx;
    KBKDF *dest;

    dest = kbkdf_new(src->provctx);
    if (dest != NULL) {
        dest->ctx_init = EVP_MAC_CTX_dup(src->ctx_init);
        if (dest->ctx_init == NULL
                || !ossl_prov_memdup(src->ki, src->ki_len,
                                     &dest->ki, &dest->ki_len)
                || !ossl_prov_memdup(src->label, src->label_len,
                                     &dest->label, &dest->label_len)
                || !ossl_prov_memdup(src->context, src->context_len,
                                     &dest->context, &dest->context_len)
                || !ossl_prov_memdup(src->iv, src->iv_len,
                                     &dest->iv, &dest->iv_len))
            goto err;
        dest->mode = src->mode;
        dest->r = src->r;
        dest->use_l = src->use_l;
        dest->use_separator = src->use_separator;
        dest->is_kmac = src->is_kmac;
    }
    return dest;

 err:
    kbkdf_free(dest);
    return NULL;
}

/* SP800-108 section 5.1 or section 5.2 depending on mode. */
static int derive(EVP_MAC_CTX *ctx_init, kbkdf_mode mode, unsigned char *iv,
                  size_t iv_len, unsigned char *label, size_t label_len,
                  unsigned char *context, size_t context_len,
                  unsigned char *k_i, size_t h, uint32_t l, int has_separator,
                  unsigned char *ko, size_t ko_len, int r)
{
    int ret = 0;
    EVP_MAC_CTX *ctx = NULL;
    size_t written = 0, to_write, k_i_len = iv_len;
    const unsigned char zero = 0;
    uint32_t counter, i;
    /*
     * From SP800-108:
     * The fixed input data is a concatenation of a Label,
     * a separation indicator 0x00, the Context, and L.
     * One or more of these fixed input data fields may be omitted.
     *
     * has_separator == 0 means that the separator is omitted.
     * Passing a value of l == 0 means that L is omitted.
     * The Context and L are omitted automatically if a NULL buffer is passed.
     */
    int has_l = (l != 0);

    /* Setup K(0) for feedback mode. */
    if (iv_len > 0)
        memcpy(k_i, iv, iv_len);

    for (counter = 1; written < ko_len; counter++) {
        i = be32(counter);

        ctx = EVP_MAC_CTX_dup(ctx_init);
        if (ctx == NULL)
            goto done;

        /* Perform feedback, if appropriate. */
        if (mode == FEEDBACK && !EVP_MAC_update(ctx, k_i, k_i_len))
            goto done;

        if (!EVP_MAC_update(ctx, 4 - (r / 8) + (unsigned char *)&i, r / 8)
            || !EVP_MAC_update(ctx, label, label_len)
            || (has_separator && !EVP_MAC_update(ctx, &zero, 1))
            || !EVP_MAC_update(ctx, context, context_len)
            || (has_l && !EVP_MAC_update(ctx, (unsigned char *)&l, 4))
            || !EVP_MAC_final(ctx, k_i, NULL, h))
            goto done;

        to_write = ko_len - written;
        memcpy(ko + written, k_i, ossl_min(to_write, h));
        written += h;

        k_i_len = h;
        EVP_MAC_CTX_free(ctx);
        ctx = NULL;
    }

    ret = 1;
done:
    EVP_MAC_CTX_free(ctx);
    return ret;
}

/* This must be run before the key is set */
static int kmac_init(EVP_MAC_CTX *ctx, const unsigned char *custom, size_t customlen)
{
    OSSL_PARAM params[2];

    if (custom == NULL || customlen == 0)
        return 1;
    params[0] = OSSL_PARAM_construct_octet_string(OSSL_MAC_PARAM_CUSTOM,
                                                  (void *)custom, customlen);
    params[1] = OSSL_PARAM_construct_end();
    return EVP_MAC_CTX_set_params(ctx, params) > 0;
}

static int kmac_derive(EVP_MAC_CTX *ctx, unsigned char *out, size_t outlen,
                       const unsigned char *context, size_t contextlen)
{
    OSSL_PARAM params[2];

    params[0] = OSSL_PARAM_construct_size_t(OSSL_MAC_PARAM_SIZE, &outlen);
    params[1] = OSSL_PARAM_construct_end();
    return EVP_MAC_CTX_set_params(ctx, params) > 0
           && EVP_MAC_update(ctx, context, contextlen)
           && EVP_MAC_final(ctx, out, NULL, outlen);
}

static int kbkdf_derive(void *vctx, unsigned char *key, size_t keylen,
                        const OSSL_PARAM params[])
{
    KBKDF *ctx = (KBKDF *)vctx;
    int ret = 0;
    unsigned char *k_i = NULL;
    uint32_t l = 0;
    size_t h = 0;
    uint64_t counter_max;

    if (!ossl_prov_is_running() || !kbkdf_set_ctx_params(ctx, params))
        return 0;

    /* label, context, and iv are permitted to be empty.  Check everything
     * else. */
    if (ctx->ctx_init == NULL) {
        if (ctx->ki_len == 0 || ctx->ki == NULL) {
            ERR_raise(ERR_LIB_PROV, PROV_R_NO_KEY_SET);
            return 0;
        }
        /* Could either be missing MAC or missing message digest or missing
         * cipher - arbitrarily, I pick this one. */
        ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MAC);
        return 0;
    }

    /* Fail if the output length is zero */
    if (keylen == 0) {
        ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH);
        return 0;
    }

    if (ctx->is_kmac) {
        ret = kmac_derive(ctx->ctx_init, key, keylen,
                          ctx->context, ctx->context_len);
        goto done;
    }

    h = EVP_MAC_CTX_get_mac_size(ctx->ctx_init);
    if (h == 0)
        goto done;

    if (ctx->iv_len != 0 && ctx->iv_len != h) {
        ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_SEED_LENGTH);
        goto done;
    }

    if (ctx->mode == COUNTER) {
        /* Fail if keylen is too large for r */
        counter_max = (uint64_t)1 << (uint64_t)ctx->r;
        if ((uint64_t)(keylen / h) >= counter_max) {
            ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH);
            goto done;
        }
    }

    if (ctx->use_l != 0)
        l = be32(keylen * 8);

    k_i = OPENSSL_zalloc(h);
    if (k_i == NULL)
        goto done;

    ret = derive(ctx->ctx_init, ctx->mode, ctx->iv, ctx->iv_len, ctx->label,
                 ctx->label_len, ctx->context, ctx->context_len, k_i, h, l,
                 ctx->use_separator, key, keylen, ctx->r);
done:
    if (ret != 1)
        OPENSSL_cleanse(key, keylen);
    OPENSSL_clear_free(k_i, h);
    return ret;
}

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

    OPENSSL_clear_free(*out, *out_len);
    *out = NULL;
    return OSSL_PARAM_get_octet_string(p, (void **)out, 0, out_len);
}

static int kbkdf_set_ctx_params(void *vctx, const OSSL_PARAM params[])
{
    KBKDF *ctx = (KBKDF *)vctx;
    OSSL_LIB_CTX *libctx = PROV_LIBCTX_OF(ctx->provctx);
    const OSSL_PARAM *p;

    if (params == NULL)
        return 1;

    if (!ossl_prov_macctx_load_from_params(&ctx->ctx_init, params, NULL,
                                           NULL, NULL, libctx))
        return 0;
    if (ctx->ctx_init != NULL) {
        ctx->is_kmac = 0;
        if (EVP_MAC_is_a(EVP_MAC_CTX_get0_mac(ctx->ctx_init),
                         OSSL_MAC_NAME_KMAC128)
            || EVP_MAC_is_a(EVP_MAC_CTX_get0_mac(ctx->ctx_init),
                            OSSL_MAC_NAME_KMAC256)) {
            ctx->is_kmac = 1;
        } else if (!EVP_MAC_is_a(EVP_MAC_CTX_get0_mac(ctx->ctx_init),
                                 OSSL_MAC_NAME_HMAC)
                   && !EVP_MAC_is_a(EVP_MAC_CTX_get0_mac(ctx->ctx_init),
                                    OSSL_MAC_NAME_CMAC)) {
            ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_MAC);
            return 0;
        }
    }

    p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_MODE);
    if (p != NULL
        && OPENSSL_strncasecmp("counter", p->data, p->data_size) == 0) {
        ctx->mode = COUNTER;
    } else if (p != NULL
               && OPENSSL_strncasecmp("feedback", p->data, p->data_size) == 0) {
        ctx->mode = FEEDBACK;
    } else if (p != NULL) {
        ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_MODE);
        return 0;
    }

    p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_KEY);
    if (p != NULL && !kbkdf_set_buffer(&ctx->ki, &ctx->ki_len, p))
        return 0;

    p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SALT);
    if (p != NULL && !kbkdf_set_buffer(&ctx->label, &ctx->label_len, p))
        return 0;

    p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_INFO);
    if (p != NULL && !kbkdf_set_buffer(&ctx->context, &ctx->context_len, p))
        return 0;

    p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SEED);
    if (p != NULL && !kbkdf_set_buffer(&ctx->iv, &ctx->iv_len, p))
        return 0;

    p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_KBKDF_USE_L);
    if (p != NULL && !OSSL_PARAM_get_int(p, &ctx->use_l))
        return 0;

    p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_KBKDF_R);
    if (p != NULL) {
        int new_r = 0;

        if (!OSSL_PARAM_get_int(p, &new_r))
            return 0;
        if (new_r != 8 && new_r != 16 && new_r != 24 && new_r != 32)
            return 0;
        ctx->r = new_r;
    }

    p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_KBKDF_USE_SEPARATOR);
    if (p != NULL && !OSSL_PARAM_get_int(p, &ctx->use_separator))
        return 0;

    /* Set up digest context, if we can. */
    if (ctx->ctx_init != NULL && ctx->ki_len != 0) {
        if ((ctx->is_kmac && !kmac_init(ctx->ctx_init, ctx->label, ctx->label_len))
            || !EVP_MAC_init(ctx->ctx_init, ctx->ki, ctx->ki_len, NULL))
            return 0;
    }
    return 1;
}

static const OSSL_PARAM *kbkdf_settable_ctx_params(ossl_unused void *ctx,
                                                   ossl_unused void *provctx)
{
    static const OSSL_PARAM known_settable_ctx_params[] = {
        OSSL_PARAM_octet_string(OSSL_KDF_PARAM_INFO, NULL, 0),
        OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SALT, NULL, 0),
        OSSL_PARAM_octet_string(OSSL_KDF_PARAM_KEY, NULL, 0),
        OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SEED, NULL, 0),
        OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_DIGEST, NULL, 0),
        OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_CIPHER, NULL, 0),
        OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_MAC, NULL, 0),
        OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_MODE, NULL, 0),
        OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_PROPERTIES, NULL, 0),
        OSSL_PARAM_int(OSSL_KDF_PARAM_KBKDF_USE_L, NULL),
        OSSL_PARAM_int(OSSL_KDF_PARAM_KBKDF_USE_SEPARATOR, NULL),
        OSSL_PARAM_int(OSSL_KDF_PARAM_KBKDF_R, NULL),
        OSSL_PARAM_END,
    };
    return known_settable_ctx_params;
}

static int kbkdf_get_ctx_params(void *vctx, OSSL_PARAM params[])
{
    OSSL_PARAM *p;

    p = OSSL_PARAM_locate(params, OSSL_KDF_PARAM_SIZE);
    if (p == NULL)
        return -2;

    /* KBKDF can produce results as large as you like. */
    return OSSL_PARAM_set_size_t(p, SIZE_MAX);
}

static const OSSL_PARAM *kbkdf_gettable_ctx_params(ossl_unused void *ctx,
                                                   ossl_unused void *provctx)
{
    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 ossl_kdf_kbkdf_functions[] = {
    { OSSL_FUNC_KDF_NEWCTX, (void(*)(void))kbkdf_new },
    { OSSL_FUNC_KDF_DUPCTX, (void(*)(void))kbkdf_dup },
    { OSSL_FUNC_KDF_FREECTX, (void(*)(void))kbkdf_free },
    { OSSL_FUNC_KDF_RESET, (void(*)(void))kbkdf_reset },
    { OSSL_FUNC_KDF_DERIVE, (void(*)(void))kbkdf_derive },
    { OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS,
      (void(*)(void))kbkdf_settable_ctx_params },
    { OSSL_FUNC_KDF_SET_CTX_PARAMS, (void(*)(void))kbkdf_set_ctx_params },
    { OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS,
      (void(*)(void))kbkdf_gettable_ctx_params },
    { OSSL_FUNC_KDF_GET_CTX_PARAMS, (void(*)(void))kbkdf_get_ctx_params },
    { 0, NULL },
};

Coverage Report

Created: 2025-06-13 06:58

Line	Count	Source (jump to first uncovered line)
1		/*
2		* Copyright 2019-2024 The OpenSSL Project Authors. All Rights Reserved.
3		* Copyright 2019 Red Hat, Inc.
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		* This implements https://csrc.nist.gov/publications/detail/sp/800-108/final
13		* section 5.1 ("counter mode") and section 5.2 ("feedback mode") in both HMAC
14		* and CMAC. That document does not name the KDFs it defines; the name is
15		* derived from
16		* https://csrc.nist.gov/Projects/Cryptographic-Algorithm-Validation-Program/Key-Derivation
17		*
18		* Note that section 5.3 ("double-pipeline mode") is not implemented, though
19		* it would be possible to do so in the future.
20		*
21		* These versions all assume the counter is used. It would be relatively
22		* straightforward to expose a configuration handle should the need arise.
23		*
24		* Variable names attempt to match those of SP800-108.
25		*/
26
27		#include <stdarg.h>
28		#include <stdlib.h>
29		#include <string.h>
30
31		#include <openssl/core_names.h>
32		#include <openssl/evp.h>
33		#include <openssl/hmac.h>
34		#include <openssl/kdf.h>
35		#include <openssl/params.h>
36		#include <openssl/proverr.h>
37
38		#include "internal/cryptlib.h"
39		#include "crypto/evp.h"
40		#include "internal/numbers.h"
41		#include "internal/endian.h"
42		#include "prov/implementations.h"
43		#include "prov/provider_ctx.h"
44		#include "prov/provider_util.h"
45		#include "prov/providercommon.h"
46
47		#include "internal/e_os.h"
48
49	19	#define ossl_min(a, b) ((a) < (b)) ? (a) : (b)
50
51		typedef enum {
52		COUNTER = 0,
53		FEEDBACK
54		} kbkdf_mode;
55
56		/* Our context structure. */
57		typedef struct {
58		void *provctx;
59		kbkdf_mode mode;
60		EVP_MAC_CTX *ctx_init;
61
62		/* Names are lowercased versions of those found in SP800-108. */
63		int r;
64		unsigned char *ki;
65		size_t ki_len;
66		unsigned char *label;
67		size_t label_len;
68		unsigned char *context;
69		size_t context_len;
70		unsigned char *iv;
71		size_t iv_len;
72		int use_l;
73		int is_kmac;
74		int use_separator;
75		} KBKDF;
76
77		/* Definitions needed for typechecking. */
78		static OSSL_FUNC_kdf_newctx_fn kbkdf_new;
79		static OSSL_FUNC_kdf_dupctx_fn kbkdf_dup;
80		static OSSL_FUNC_kdf_freectx_fn kbkdf_free;
81		static OSSL_FUNC_kdf_reset_fn kbkdf_reset;
82		static OSSL_FUNC_kdf_derive_fn kbkdf_derive;
83		static OSSL_FUNC_kdf_settable_ctx_params_fn kbkdf_settable_ctx_params;
84		static OSSL_FUNC_kdf_set_ctx_params_fn kbkdf_set_ctx_params;
85		static OSSL_FUNC_kdf_gettable_ctx_params_fn kbkdf_gettable_ctx_params;
86		static OSSL_FUNC_kdf_get_ctx_params_fn kbkdf_get_ctx_params;
87
88		/* Not all platforms have htobe32(). */
89		static uint32_t be32(uint32_t host)
90	24	{
91	24	uint32_t big = 0;
92	24	DECLARE_IS_ENDIAN;
93
94	24	if (!IS_LITTLE_ENDIAN)
95	0	return host;
96
97	24	big \|= (host & 0xff000000) >> 24;
98	24	big \|= (host & 0x00ff0000) >> 8;
99	24	big \|= (host & 0x0000ff00) << 8;
100	24	big \|= (host & 0x000000ff) << 24;
101	24	return big;
102	24	}
103
104		static void init(KBKDF *ctx)
105	180	{
106	180	ctx->r = 32;
107	180	ctx->use_l = 1;
108	180	ctx->use_separator = 1;
109	180	ctx->is_kmac = 0;
110	180	}
111
112		static void kbkdf_new(void provctx)
113	90	{
114	90	KBKDF *ctx;
115
116	90	if (!ossl_prov_is_running())
117	0	return NULL;
118
119	90	ctx = OPENSSL_zalloc(sizeof(*ctx));
120	90	if (ctx == NULL) {
121	0	ERR_raise(ERR_LIB_PROV, ERR_R_MALLOC_FAILURE);
122	0	return NULL;
123	0	}
124
125	90	ctx->provctx = provctx;
126	90	init(ctx);
127	90	return ctx;
128	90	}
129
130		static void kbkdf_free(void *vctx)
131	90	{
132	90	KBKDF ctx = (KBKDF )vctx;
133
134	90	if (ctx != NULL) {
135	90	kbkdf_reset(ctx);
136	90	OPENSSL_free(ctx);
137	90	}
138	90	}
139
140		static void kbkdf_reset(void *vctx)
141	90	{
142	90	KBKDF ctx = (KBKDF )vctx;
143	90	void *provctx = ctx->provctx;
144
145	90	EVP_MAC_CTX_free(ctx->ctx_init);
146	90	OPENSSL_clear_free(ctx->context, ctx->context_len);
147	90	OPENSSL_clear_free(ctx->label, ctx->label_len);
148	90	OPENSSL_clear_free(ctx->ki, ctx->ki_len);
149	90	OPENSSL_clear_free(ctx->iv, ctx->iv_len);
150	90	memset(ctx, 0, sizeof(*ctx));
151	90	ctx->provctx = provctx;
152	90	init(ctx);
153	90	}
154
155		static void kbkdf_dup(void vctx)
156	0	{
157	0	const KBKDF src = (const KBKDF )vctx;
158	0	KBKDF *dest;
159
160	0	dest = kbkdf_new(src->provctx);
161	0	if (dest != NULL) {
162	0	dest->ctx_init = EVP_MAC_CTX_dup(src->ctx_init);
163	0	if (dest->ctx_init == NULL
164	0	\|\| !ossl_prov_memdup(src->ki, src->ki_len,
165	0	&dest->ki, &dest->ki_len)
166	0	\|\| !ossl_prov_memdup(src->label, src->label_len,
167	0	&dest->label, &dest->label_len)
168	0	\|\| !ossl_prov_memdup(src->context, src->context_len,
169	0	&dest->context, &dest->context_len)
170	0	\|\| !ossl_prov_memdup(src->iv, src->iv_len,
171	0	&dest->iv, &dest->iv_len))
172	0	goto err;
173	0	dest->mode = src->mode;
174	0	dest->r = src->r;
175	0	dest->use_l = src->use_l;
176	0	dest->use_separator = src->use_separator;
177	0	dest->is_kmac = src->is_kmac;
178	0	}
179	0	return dest;
180
181	0	err:
182	0	kbkdf_free(dest);
183	0	return NULL;
184	0	}
185
186		/* SP800-108 section 5.1 or section 5.2 depending on mode. */
187		static int derive(EVP_MAC_CTX ctx_init, kbkdf_mode mode, unsigned char iv,
188		size_t iv_len, unsigned char *label, size_t label_len,
189		unsigned char *context, size_t context_len,
190		unsigned char *k_i, size_t h, uint32_t l, int has_separator,
191		unsigned char *ko, size_t ko_len, int r)
192	13	{
193	13	int ret = 0;
194	13	EVP_MAC_CTX *ctx = NULL;
195	13	size_t written = 0, to_write, k_i_len = iv_len;
196	13	const unsigned char zero = 0;
197	13	uint32_t counter, i;
198		/*
199		* From SP800-108:
200		* The fixed input data is a concatenation of a Label,
201		* a separation indicator 0x00, the Context, and L.
202		* One or more of these fixed input data fields may be omitted.
203		*
204		* has_separator == 0 means that the separator is omitted.
205		* Passing a value of l == 0 means that L is omitted.
206		* The Context and L are omitted automatically if a NULL buffer is passed.
207		*/
208	13	int has_l = (l != 0);
209
210		/* Setup K(0) for feedback mode. */
211	13	if (iv_len > 0)
212	4	memcpy(k_i, iv, iv_len);
213
214	32	for (counter = 1; written < ko_len; counter++) {
215	19	i = be32(counter);
216
217	19	ctx = EVP_MAC_CTX_dup(ctx_init);
218	19	if (ctx == NULL)
219	0	goto done;
220
221		/* Perform feedback, if appropriate. */
222	19	if (mode == FEEDBACK && !EVP_MAC_update(ctx, k_i, k_i_len))
223	0	goto done;
224
225	19	if (!EVP_MAC_update(ctx, 4 - (r / 8) + (unsigned char *)&i, r / 8)
226	19	\|\| !EVP_MAC_update(ctx, label, label_len)
227	19	\|\| (has_separator && !EVP_MAC_update(ctx, &zero, 1))
228	19	\|\| !EVP_MAC_update(ctx, context, context_len)
229	19	\|\| (has_l && !EVP_MAC_update(ctx, (unsigned char *)&l, 4))
230	19	\|\| !EVP_MAC_final(ctx, k_i, NULL, h))
231	0	goto done;
232
233	19	to_write = ko_len - written;
234	19	memcpy(ko + written, k_i, ossl_min(to_write, h));
235	19	written += h;
236
237	19	k_i_len = h;
238	19	EVP_MAC_CTX_free(ctx);
239	19	ctx = NULL;
240	19	}
241
242	13	ret = 1;
243	13	done:
244	13	EVP_MAC_CTX_free(ctx);
245	13	return ret;
246	13	}
247
248		/* This must be run before the key is set */
249		static int kmac_init(EVP_MAC_CTX ctx, const unsigned char custom, size_t customlen)
250	13	{
251	13	OSSL_PARAM params[2];
252
253	13	if (custom == NULL \|\| customlen == 0)
254	2	return 1;
255	11	params[0] = OSSL_PARAM_construct_octet_string(OSSL_MAC_PARAM_CUSTOM,
256	11	(void *)custom, customlen);
257	11	params[1] = OSSL_PARAM_construct_end();
258	11	return EVP_MAC_CTX_set_params(ctx, params) > 0;
259	13	}
260
261		static int kmac_derive(EVP_MAC_CTX ctx, unsigned char out, size_t outlen,
262		const unsigned char *context, size_t contextlen)
263	17	{
264	17	OSSL_PARAM params[2];
265
266	17	params[0] = OSSL_PARAM_construct_size_t(OSSL_MAC_PARAM_SIZE, &outlen);
267	17	params[1] = OSSL_PARAM_construct_end();
268	17	return EVP_MAC_CTX_set_params(ctx, params) > 0
269	17	&& EVP_MAC_update(ctx, context, contextlen)
270	17	&& EVP_MAC_final(ctx, out, NULL, outlen);
271	17	}
272
273		static int kbkdf_derive(void vctx, unsigned char key, size_t keylen,
274		const OSSL_PARAM params[])
275	68	{
276	68	KBKDF ctx = (KBKDF )vctx;
277	68	int ret = 0;
278	68	unsigned char *k_i = NULL;
279	68	uint32_t l = 0;
280	68	size_t h = 0;
281	68	uint64_t counter_max;
282
283	68	if (!ossl_prov_is_running() \|\| !kbkdf_set_ctx_params(ctx, params))
284	0	return 0;
285
286		/* label, context, and iv are permitted to be empty. Check everything
287		* else. */
288	68	if (ctx->ctx_init == NULL) {
289	0	if (ctx->ki_len == 0 \|\| ctx->ki == NULL) {
290	0	ERR_raise(ERR_LIB_PROV, PROV_R_NO_KEY_SET);
291	0	return 0;
292	0	}
293		/* Could either be missing MAC or missing message digest or missing
294		* cipher - arbitrarily, I pick this one. */
295	0	ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MAC);
296	0	return 0;
297	0	}
298
299		/* Fail if the output length is zero */
300	68	if (keylen == 0) {
301	0	ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH);
302	0	return 0;
303	0	}
304
305	68	if (ctx->is_kmac) {
306	17	ret = kmac_derive(ctx->ctx_init, key, keylen,
307	17	ctx->context, ctx->context_len);
308	17	goto done;
309	17	}
310
311	51	h = EVP_MAC_CTX_get_mac_size(ctx->ctx_init);
312	51	if (h == 0)
313	2	goto done;
314
315	49	if (ctx->iv_len != 0 && ctx->iv_len != h) {
316	36	ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_SEED_LENGTH);
317	36	goto done;
318	36	}
319
320	13	if (ctx->mode == COUNTER) {
321		/* Fail if keylen is too large for r */
322	13	counter_max = (uint64_t)1 << (uint64_t)ctx->r;
323	13	if ((uint64_t)(keylen / h) >= counter_max) {
324	0	ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH);
325	0	goto done;
326	0	}
327	13	}
328
329	13	if (ctx->use_l != 0)
330	5	l = be32(keylen * 8);
331
332	13	k_i = OPENSSL_zalloc(h);
333	13	if (k_i == NULL)
334	0	goto done;
335
336	13	ret = derive(ctx->ctx_init, ctx->mode, ctx->iv, ctx->iv_len, ctx->label,
337	13	ctx->label_len, ctx->context, ctx->context_len, k_i, h, l,
338	13	ctx->use_separator, key, keylen, ctx->r);
339	68	done:
340	68	if (ret != 1)
341	47	OPENSSL_cleanse(key, keylen);
342	68	OPENSSL_clear_free(k_i, h);
343	68	return ret;
344	13	}
345
346		static int kbkdf_set_buffer(unsigned char *out, size_t out_len,
347		const OSSL_PARAM *p)
348	0	{
349	0	if (p->data == NULL \|\| p->data_size == 0)
350	0	return 1;
351
352	0	OPENSSL_clear_free(out, out_len);
353	0	*out = NULL;
354	0	return OSSL_PARAM_get_octet_string(p, (void **)out, 0, out_len);
355	0	}
356
357		static int kbkdf_set_ctx_params(void *vctx, const OSSL_PARAM params[])
358		{
359		KBKDF ctx = (KBKDF )vctx;
360		OSSL_LIB_CTX *libctx = PROV_LIBCTX_OF(ctx->provctx);
361		const OSSL_PARAM *p;
362
363		if (params == NULL)
364		return 1;
365
366		if (!ossl_prov_macctx_load_from_params(&ctx->ctx_init, params, NULL,
367		NULL, NULL, libctx))
368		return 0;
369		if (ctx->ctx_init != NULL) {
370		ctx->is_kmac = 0;
371		if (EVP_MAC_is_a(EVP_MAC_CTX_get0_mac(ctx->ctx_init),
372		OSSL_MAC_NAME_KMAC128)
373		\|\| EVP_MAC_is_a(EVP_MAC_CTX_get0_mac(ctx->ctx_init),
374		OSSL_MAC_NAME_KMAC256)) {
375		ctx->is_kmac = 1;
376		} else if (!EVP_MAC_is_a(EVP_MAC_CTX_get0_mac(ctx->ctx_init),
377		OSSL_MAC_NAME_HMAC)
378		&& !EVP_MAC_is_a(EVP_MAC_CTX_get0_mac(ctx->ctx_init),
379		OSSL_MAC_NAME_CMAC)) {
380		ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_MAC);
381		return 0;
382		}
383		}
384
385		p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_MODE);
386		if (p != NULL
387		&& OPENSSL_strncasecmp("counter", p->data, p->data_size) == 0) {
388		ctx->mode = COUNTER;
389		} else if (p != NULL
390		&& OPENSSL_strncasecmp("feedback", p->data, p->data_size) == 0) {
391		ctx->mode = FEEDBACK;
392		} else if (p != NULL) {
393		ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_MODE);
394		return 0;
395		}
396
397		p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_KEY);
398		if (p != NULL && !kbkdf_set_buffer(&ctx->ki, &ctx->ki_len, p))
399		return 0;
400
401		p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SALT);
402		if (p != NULL && !kbkdf_set_buffer(&ctx->label, &ctx->label_len, p))
403		return 0;
404
405		p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_INFO);
406		if (p != NULL && !kbkdf_set_buffer(&ctx->context, &ctx->context_len, p))
407		return 0;
408
409		p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SEED);
410		if (p != NULL && !kbkdf_set_buffer(&ctx->iv, &ctx->iv_len, p))
411		return 0;
412
413		p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_KBKDF_USE_L);
414		if (p != NULL && !OSSL_PARAM_get_int(p, &ctx->use_l))
415		return 0;
416
417		p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_KBKDF_R);
418		if (p != NULL) {
419		int new_r = 0;
420
421		if (!OSSL_PARAM_get_int(p, &new_r))
422		return 0;
423		if (new_r != 8 && new_r != 16 && new_r != 24 && new_r != 32)
424		return 0;
425		ctx->r = new_r;
426		}
427
428		p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_KBKDF_USE_SEPARATOR);
429		if (p != NULL && !OSSL_PARAM_get_int(p, &ctx->use_separator))
430		return 0;
431
432		/* Set up digest context, if we can. */
433		if (ctx->ctx_init != NULL && ctx->ki_len != 0) {
434		if ((ctx->is_kmac && !kmac_init(ctx->ctx_init, ctx->label, ctx->label_len))
435		\|\| !EVP_MAC_init(ctx->ctx_init, ctx->ki, ctx->ki_len, NULL))
436		return 0;
437		}
438		return 1;
439		}
440
441		static const OSSL_PARAM kbkdf_settable_ctx_params(ossl_unused void ctx,
442		ossl_unused void *provctx)
443	90	{
444	90	static const OSSL_PARAM known_settable_ctx_params[] = {
445	90	OSSL_PARAM_octet_string(OSSL_KDF_PARAM_INFO, NULL, 0),
446	90	OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SALT, NULL, 0),
447	90	OSSL_PARAM_octet_string(OSSL_KDF_PARAM_KEY, NULL, 0),
448	90	OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SEED, NULL, 0),
449	90	OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_DIGEST, NULL, 0),
450	90	OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_CIPHER, NULL, 0),
451	90	OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_MAC, NULL, 0),
452	90	OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_MODE, NULL, 0),
453	90	OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_PROPERTIES, NULL, 0),
454	90	OSSL_PARAM_int(OSSL_KDF_PARAM_KBKDF_USE_L, NULL),
455	90	OSSL_PARAM_int(OSSL_KDF_PARAM_KBKDF_USE_SEPARATOR, NULL),
456	90	OSSL_PARAM_int(OSSL_KDF_PARAM_KBKDF_R, NULL),
457	90	OSSL_PARAM_END,
458	90	};
459	90	return known_settable_ctx_params;
460	90	}
461
462		static int kbkdf_get_ctx_params(void *vctx, OSSL_PARAM params[])
463	0	{
464	0	OSSL_PARAM *p;
465
466	0	p = OSSL_PARAM_locate(params, OSSL_KDF_PARAM_SIZE);
467	0	if (p == NULL)
468	0	return -2;
469
470		/* KBKDF can produce results as large as you like. */
471	0	return OSSL_PARAM_set_size_t(p, SIZE_MAX);
472	0	}
473
474		static const OSSL_PARAM kbkdf_gettable_ctx_params(ossl_unused void ctx,
475		ossl_unused void *provctx)
476	0	{
477	0	static const OSSL_PARAM known_gettable_ctx_params[] =
478	0	{ OSSL_PARAM_size_t(OSSL_KDF_PARAM_SIZE, NULL), OSSL_PARAM_END };
479	0	return known_gettable_ctx_params;
480	0	}
481
482		const OSSL_DISPATCH ossl_kdf_kbkdf_functions[] = {
483		{ OSSL_FUNC_KDF_NEWCTX, (void(*)(void))kbkdf_new },
484		{ OSSL_FUNC_KDF_DUPCTX, (void(*)(void))kbkdf_dup },
485		{ OSSL_FUNC_KDF_FREECTX, (void(*)(void))kbkdf_free },
486		{ OSSL_FUNC_KDF_RESET, (void(*)(void))kbkdf_reset },
487		{ OSSL_FUNC_KDF_DERIVE, (void(*)(void))kbkdf_derive },
488		{ OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS,
489		(void(*)(void))kbkdf_settable_ctx_params },
490		{ OSSL_FUNC_KDF_SET_CTX_PARAMS, (void(*)(void))kbkdf_set_ctx_params },
491		{ OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS,
492		(void(*)(void))kbkdf_gettable_ctx_params },
493		{ OSSL_FUNC_KDF_GET_CTX_PARAMS, (void(*)(void))kbkdf_get_ctx_params },
494		{ 0, NULL },
495		};