[thirdparty/openssl.git] / crypto / kdf / 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 "internal/cryptlib.h"
#include "internal/evp_int.h"
#include "kdf_local.h"

struct evp_kdf_impl_st {
    const EVP_MAC *mac; /* H(x) = HMAC_hash OR H(x) = KMAC */
    const 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 */
};

#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 };

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

    if (EVP_MAC_ctrl(ctx, EVP_MAC_CTRL_SET_CUSTOM, custom, custom_len) <= 0)
        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;

    if (EVP_MAC_ctrl(ctx, EVP_MAC_CTRL_SET_SIZE, kmac_out_len) <= 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(const 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;

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

    ctx = EVP_MAC_CTX_new(kdf_mac);
    ctx_init = EVP_MAC_CTX_new(kdf_mac);
    if (ctx == NULL || ctx_init == NULL)
        goto end;
    if (hmac_md != NULL &&
            EVP_MAC_ctrl(ctx_init, EVP_MAC_CTRL_SET_MD, hmac_md) <= 0)
        goto end;

    if (EVP_MAC_ctrl(ctx_init, EVP_MAC_CTRL_SET_KEY, salt, salt_len) <= 0)
        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);

        if (!(EVP_MAC_CTX_copy(ctx, ctx_init)
                && 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))
                goto end;
            out += out_len;
            len -= out_len;
            if (len == 0)
                break;
        } else {
            if (!EVP_MAC_final(ctx, mac, NULL))
                goto end;
            memcpy(out, mac, len);
            break;
        }
    }
    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 EVP_KDF_IMPL *sskdf_new(void)
{
    EVP_KDF_IMPL *impl;

    if ((impl = OPENSSL_zalloc(sizeof(*impl))) == NULL)
        KDFerr(KDF_F_SSKDF_NEW, ERR_R_MALLOC_FAILURE);
    return impl;
}

static void sskdf_reset(EVP_KDF_IMPL *impl)
{
    OPENSSL_clear_free(impl->secret, impl->secret_len);
    OPENSSL_clear_free(impl->info, impl->info_len);
    OPENSSL_clear_free(impl->salt, impl->salt_len);
    memset(impl, 0, sizeof(*impl));
}

static void sskdf_free(EVP_KDF_IMPL *impl)
{
    sskdf_reset(impl);
    OPENSSL_free(impl);
}

static int sskdf_set_buffer(va_list args, unsigned char **out, size_t *out_len)
{
    const unsigned char *p;
    size_t len;

    p = va_arg(args, const unsigned char *);
    len = va_arg(args, size_t);
    if (len == 0 || p == NULL)
        return 1;

    OPENSSL_free(*out);
    *out = OPENSSL_memdup(p, len);
    if (*out == NULL)
        return 0;

    *out_len = len;
    return 1;
}

static int sskdf_ctrl(EVP_KDF_IMPL *impl, int cmd, va_list args)
{
    const EVP_MD *md;
    const EVP_MAC *mac;

    switch (cmd) {
    case EVP_KDF_CTRL_SET_KEY:
        return sskdf_set_buffer(args, &impl->secret, &impl->secret_len);

    case EVP_KDF_CTRL_SET_SSKDF_INFO:
        return sskdf_set_buffer(args, &impl->info, &impl->info_len);

    case EVP_KDF_CTRL_SET_MD:
        md = va_arg(args, const EVP_MD *);
        if (md == NULL)
            return 0;

        impl->md = md;
        return 1;

    case EVP_KDF_CTRL_SET_MAC:
        mac = va_arg(args, const EVP_MAC *);
        if (mac == NULL)
            return 0;

        impl->mac = mac;
        return 1;

    case EVP_KDF_CTRL_SET_SALT:
        return sskdf_set_buffer(args, &impl->salt, &impl->salt_len);

    case EVP_KDF_CTRL_SET_MAC_SIZE:
        impl->out_len = va_arg(args, size_t);
        return 1;

    default:
        return -2;
    }
}

/* Pass a mac to a ctrl */
static int sskdf_mac2ctrl(EVP_KDF_IMPL *impl,
                          int (*ctrl)(EVP_KDF_IMPL *impl, int cmd, va_list args),
                          int cmd, const char *mac_name)
{
    const EVP_MAC *mac;

    if (mac_name == NULL || (mac = EVP_get_macbyname(mac_name)) == NULL) {
        KDFerr(KDF_F_SSKDF_MAC2CTRL, KDF_R_INVALID_MAC_TYPE);
        return 0;
    }
    return call_ctrl(ctrl, impl, cmd, mac);
}

static int sskdf_ctrl_str(EVP_KDF_IMPL *impl, const char *type,
                          const char *value)
{
    if (strcmp(type, "secret") == 0 || strcmp(type, "key") == 0)
         return kdf_str2ctrl(impl, sskdf_ctrl, EVP_KDF_CTRL_SET_KEY,
                             value);

    if (strcmp(type, "hexsecret") == 0 || strcmp(type, "hexkey") == 0)
        return kdf_hex2ctrl(impl, sskdf_ctrl, EVP_KDF_CTRL_SET_KEY,
                            value);

    if (strcmp(type, "info") == 0)
        return kdf_str2ctrl(impl, sskdf_ctrl, EVP_KDF_CTRL_SET_SSKDF_INFO,
                            value);

    if (strcmp(type, "hexinfo") == 0)
        return kdf_hex2ctrl(impl, sskdf_ctrl, EVP_KDF_CTRL_SET_SSKDF_INFO,
                            value);

    if (strcmp(type, "digest") == 0)
        return kdf_md2ctrl(impl, sskdf_ctrl, EVP_KDF_CTRL_SET_MD, value);

    if (strcmp(type, "mac") == 0)
        return sskdf_mac2ctrl(impl, sskdf_ctrl, EVP_KDF_CTRL_SET_MAC, value);

    if (strcmp(type, "salt") == 0)
        return kdf_str2ctrl(impl, sskdf_ctrl, EVP_KDF_CTRL_SET_SALT, value);

    if (strcmp(type, "hexsalt") == 0)
        return kdf_hex2ctrl(impl, sskdf_ctrl, EVP_KDF_CTRL_SET_SALT, value);


    if (strcmp(type, "maclen") == 0) {
        int val = atoi(value);
        if (val < 0) {
            KDFerr(KDF_F_SSKDF_CTRL_STR, KDF_R_VALUE_ERROR);
            return 0;
        }
        return call_ctrl(sskdf_ctrl, impl, EVP_KDF_CTRL_SET_MAC_SIZE,
                         (size_t)val);
    }
    return -2;
}

static size_t sskdf_size(EVP_KDF_IMPL *impl)
{
    int len;

    if (impl->md == NULL) {
        KDFerr(KDF_F_SSKDF_SIZE, KDF_R_MISSING_MESSAGE_DIGEST);
        return 0;
    }
    len = EVP_MD_size(impl->md);
    return (len <= 0) ? 0 : (size_t)len;
}

static int sskdf_derive(EVP_KDF_IMPL *impl, unsigned char *key, size_t keylen)
{
    if (impl->secret == NULL) {
        KDFerr(KDF_F_SSKDF_DERIVE, KDF_R_MISSING_SECRET);
        return 0;
    }

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

        nid = EVP_MAC_nid(impl->mac);
        if (nid == EVP_MAC_HMAC) {
            /* H(x) = HMAC(x, salt, hash) */
            if (impl->md == NULL) {
                KDFerr(KDF_F_SSKDF_DERIVE, KDF_R_MISSING_MESSAGE_DIGEST);
                return 0;
            }
            default_salt_len = EVP_MD_block_size(impl->md);
            if (default_salt_len <= 0)
                return 0;
        } else if (nid == EVP_MAC_KMAC128 || nid == EVP_MAC_KMAC256) {
            /* H(x) = KMACzzz(x, salt, custom) */
            custom = kmac_custom_str;
            custom_len = sizeof(kmac_custom_str);
            if (nid == EVP_MAC_KMAC128)
                default_salt_len = SSKDF_KMAC128_DEFAULT_SALT_SIZE;
            else
                default_salt_len = SSKDF_KMAC256_DEFAULT_SALT_SIZE;
        } else {
            KDFerr(KDF_F_SSKDF_DERIVE, KDF_R_UNSUPPORTED_MAC_TYPE);
            return 0;
        }
        /* If no salt is set then use a default_salt of zeros */
        if (impl->salt == NULL || impl->salt_len <= 0) {
            impl->salt = OPENSSL_zalloc(default_salt_len);
            if (impl->salt == NULL) {
                KDFerr(KDF_F_SSKDF_DERIVE, ERR_R_MALLOC_FAILURE);
                return 0;
            }
            impl->salt_len = default_salt_len;
        }
        ret = SSKDF_mac_kdm(impl->mac, impl->md,
                            custom, custom_len, impl->out_len,
                            impl->salt, impl->salt_len,
                            impl->secret, impl->secret_len,
                            impl->info, impl->info_len, key, keylen);
        return ret;
    } else {
        /* H(x) = hash */
        if (impl->md == NULL) {
            KDFerr(KDF_F_SSKDF_DERIVE, KDF_R_MISSING_MESSAGE_DIGEST);
            return 0;
        }
        return SSKDF_hash_kdm(impl->md, impl->secret, impl->secret_len,
                              impl->info, impl->info_len, 0, key, keylen);
    }
}

static int x963kdf_derive(EVP_KDF_IMPL *impl, unsigned char *key, size_t keylen)
{
    if (impl->secret == NULL) {
        KDFerr(KDF_F_X963KDF_DERIVE, KDF_R_MISSING_SECRET);
        return 0;
    }

    if (impl->mac != NULL) {
        KDFerr(KDF_F_X963KDF_DERIVE, KDF_R_NOT_SUPPORTED);
        return 0;
    } else {
        /* H(x) = hash */
        if (impl->md == NULL) {
            KDFerr(KDF_F_X963KDF_DERIVE, KDF_R_MISSING_MESSAGE_DIGEST);
            return 0;
        }
        return SSKDF_hash_kdm(impl->md, impl->secret, impl->secret_len,
                              impl->info, impl->info_len, 1, key, keylen);
    }
}

const EVP_KDF ss_kdf_meth = {
    EVP_KDF_SS,
    sskdf_new,
    sskdf_free,
    sskdf_reset,
    sskdf_ctrl,
    sskdf_ctrl_str,
    sskdf_size,
    sskdf_derive
};

const EVP_KDF x963_kdf_meth = {
    EVP_KDF_X963,
    sskdf_new,
    sskdf_free,
    sskdf_reset,
    sskdf_ctrl,
    sskdf_ctrl_str,
    sskdf_size,
    x963kdf_derive
};
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.
	20	* Result(i) = Result(i – 1) \|\| H(counter \|\| Z \|\| FixedInfo).
	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>
	43	#include "internal/cryptlib.h"
	44	#include "internal/evp_int.h"
	45	#include "kdf_local.h"
	46
	47	struct evp_kdf_impl_st {
	48	const EVP_MAC mac; / H(x) = HMAC_hash OR H(x) = KMAC */
	49	const EVP_MD md; / H(x) = hash OR when H(x) = HMAC_hash */
	50	unsigned char *secret;
	51	size_t secret_len;
	52	unsigned char *info;
	53	size_t info_len;
	54	unsigned char *salt;
	55	size_t salt_len;
	56	size_t out_len; /* optional KMAC parameter */
	57	};
	58
	59	#define SSKDF_MAX_INLEN (1<<30)
	60	#define SSKDF_KMAC128_DEFAULT_SALT_SIZE (168 - 4)
	61	#define SSKDF_KMAC256_DEFAULT_SALT_SIZE (136 - 4)
	62
	63	/* KMAC uses a Customisation string of 'KDF' */
	64	static const unsigned char kmac_custom_str[] = { 0x4B, 0x44, 0x46 };
65
66	/*
67	* Refer to https://csrc.nist.gov/publications/detail/sp/800-56c/rev-1/final
68	* Section 4. One-Step Key Derivation using H(x) = hash(x)
8bbeaaa4 SL	69	* Note: X9.63 also uses this code with the only difference being that the
	70	* counter is appended to the secret 'z'.
	71	* i.e.
	72	* result[i] = Hash(counter \|\| z \|\| info) for One Step OR
	73	* result[i] = Hash(z \|\| counter \|\| info) for X9.63.
9537fe57 SL	74	*/
	75	static int SSKDF_hash_kdm(const EVP_MD *kdf_md,
	76	const unsigned char *z, size_t z_len,
	77	const unsigned char *info, size_t info_len,
8bbeaaa4	78	unsigned int append_ctr,
9537fe57 SL	79	unsigned char *derived_key, size_t derived_key_len)
	80	{
	81	int ret = 0, hlen;
	82	size_t counter, out_len, len = derived_key_len;
	83	unsigned char c[4];
	84	unsigned char mac[EVP_MAX_MD_SIZE];
	85	unsigned char *out = derived_key;
	86	EVP_MD_CTX ctx = NULL, ctx_init = NULL;
	87
	88	if (z_len > SSKDF_MAX_INLEN \|\| info_len > SSKDF_MAX_INLEN
	89	\|\| derived_key_len > SSKDF_MAX_INLEN
	90	\|\| derived_key_len == 0)
	91	return 0;
	92
	93	hlen = EVP_MD_size(kdf_md);
	94	if (hlen <= 0)
	95	return 0;
	96	out_len = (size_t)hlen;
	97
	98	ctx = EVP_MD_CTX_create();
	99	ctx_init = EVP_MD_CTX_create();
	100	if (ctx == NULL \|\| ctx_init == NULL)
	101	goto end;
	102
	103	if (!EVP_DigestInit(ctx_init, kdf_md))
	104	goto end;
	105
	106	for (counter = 1;; counter++) {
	107	c[0] = (unsigned char)((counter >> 24) & 0xff);
	108	c[1] = (unsigned char)((counter >> 16) & 0xff);
	109	c[2] = (unsigned char)((counter >> 8) & 0xff);
	110	c[3] = (unsigned char)(counter & 0xff);
	111
	112	if (!(EVP_MD_CTX_copy_ex(ctx, ctx_init)
8bbeaaa4	113	&& (append_ctr \|\| EVP_DigestUpdate(ctx, c, sizeof(c)))
9537fe57	114	&& EVP_DigestUpdate(ctx, z, z_len)
8bbeaaa4	115	&& (!append_ctr \|\| EVP_DigestUpdate(ctx, c, sizeof(c)))
9537fe57 SL	116	&& EVP_DigestUpdate(ctx, info, info_len)))
	117	goto end;
	118	if (len >= out_len) {
	119	if (!EVP_DigestFinal_ex(ctx, out, NULL))
	120	goto end;
	121	out += out_len;
	122	len -= out_len;
	123	if (len == 0)
	124	break;
	125	} else {
	126	if (!EVP_DigestFinal_ex(ctx, mac, NULL))
	127	goto end;
	128	memcpy(out, mac, len);
	129	break;
	130	}
	131	}
	132	ret = 1;
	133	end:
	134	EVP_MD_CTX_destroy(ctx);
	135	EVP_MD_CTX_destroy(ctx_init);
	136	OPENSSL_cleanse(mac, sizeof(mac));
	137	return ret;
	138	}
	139
	140	static int kmac_init(EVP_MAC_CTX ctx, const unsigned char custom,
	141	size_t custom_len, size_t kmac_out_len,
	142	size_t derived_key_len, unsigned char **out)
	143	{
	144	/* Only KMAC has custom data - so return if not KMAC */
	145	if (custom == NULL)
	146	return 1;
	147
17838470	148	if (EVP_MAC_ctrl(ctx, EVP_MAC_CTRL_SET_CUSTOM, custom, custom_len) <= 0)
9537fe57 SL	149	return 0;
	150
	151	/* By default only do one iteration if kmac_out_len is not specified */
	152	if (kmac_out_len == 0)
	153	kmac_out_len = derived_key_len;
	154	/* otherwise check the size is valid */
	155	else if (!(kmac_out_len == derived_key_len
	156	\|\| kmac_out_len == 20
	157	\|\| kmac_out_len == 28
	158	\|\| kmac_out_len == 32
	159	\|\| kmac_out_len == 48
	160	\|\| kmac_out_len == 64))
	161	return 0;
	162
17838470	163	if (EVP_MAC_ctrl(ctx, EVP_MAC_CTRL_SET_SIZE, kmac_out_len) <= 0)
9537fe57 SL	164	return 0;
	165
	166	/*
	167	* For kmac the output buffer can be larger than EVP_MAX_MD_SIZE: so
	168	* alloc a buffer for this case.
	169	*/
	170	if (kmac_out_len > EVP_MAX_MD_SIZE) {
	171	*out = OPENSSL_zalloc(kmac_out_len);
	172	if (*out == NULL)
	173	return 0;
	174	}
	175	return 1;
	176	}
	177
	178	/*
	179	* Refer to https://csrc.nist.gov/publications/detail/sp/800-56c/rev-1/final
	180	* Section 4. One-Step Key Derivation using MAC: i.e either
	181	* H(x) = HMAC-hash(salt, x) OR
	182	* H(x) = KMAC#(salt, x, outbits, CustomString='KDF')
	183	*/
	184	static int SSKDF_mac_kdm(const EVP_MAC kdf_mac, const EVP_MD hmac_md,
	185	const unsigned char *kmac_custom,
	186	size_t kmac_custom_len, size_t kmac_out_len,
	187	const unsigned char *salt, size_t salt_len,
	188	const unsigned char *z, size_t z_len,
	189	const unsigned char *info, size_t info_len,
	190	unsigned char *derived_key, size_t derived_key_len)
	191	{
	192	int ret = 0;
	193	size_t counter, out_len, len;
	194	unsigned char c[4];
	195	unsigned char mac_buf[EVP_MAX_MD_SIZE];
	196	unsigned char *out = derived_key;
	197	EVP_MAC_CTX ctx = NULL, ctx_init = NULL;
	198	unsigned char mac = mac_buf, kmac_buffer = NULL;
	199
	200	if (z_len > SSKDF_MAX_INLEN \|\| info_len > SSKDF_MAX_INLEN
	201	\|\| derived_key_len > SSKDF_MAX_INLEN
	202	\|\| derived_key_len == 0)
	203	return 0;
	204
	205	ctx = EVP_MAC_CTX_new(kdf_mac);
	206	ctx_init = EVP_MAC_CTX_new(kdf_mac);
	207	if (ctx == NULL \|\| ctx_init == NULL)
	208	goto end;
	209	if (hmac_md != NULL &&
17838470	210	EVP_MAC_ctrl(ctx_init, EVP_MAC_CTRL_SET_MD, hmac_md) <= 0)
9537fe57 SL	211	goto end;
9537fe57 SL	212
17838470	213	if (EVP_MAC_ctrl(ctx_init, EVP_MAC_CTRL_SET_KEY, salt, salt_len) <= 0)
9537fe57 SL	214	goto end;
	215
	216	if (!kmac_init(ctx_init, kmac_custom, kmac_custom_len, kmac_out_len,
	217	derived_key_len, &kmac_buffer))
	218	goto end;
	219	if (kmac_buffer != NULL)
	220	mac = kmac_buffer;
	221
	222	if (!EVP_MAC_init(ctx_init))
	223	goto end;
	224
	225	out_len = EVP_MAC_size(ctx_init); /* output size */
	226	if (out_len <= 0)
	227	goto end;
	228	len = derived_key_len;
	229
	230	for (counter = 1;; counter++) {
	231	c[0] = (unsigned char)((counter >> 24) & 0xff);
	232	c[1] = (unsigned char)((counter >> 16) & 0xff);
	233	c[2] = (unsigned char)((counter >> 8) & 0xff);
	234	c[3] = (unsigned char)(counter & 0xff);
	235
	236	if (!(EVP_MAC_CTX_copy(ctx, ctx_init)
	237	&& EVP_MAC_update(ctx, c, sizeof(c))
	238	&& EVP_MAC_update(ctx, z, z_len)
	239	&& EVP_MAC_update(ctx, info, info_len)))
	240	goto end;
	241	if (len >= out_len) {
	242	if (!EVP_MAC_final(ctx, out, NULL))
	243	goto end;
	244	out += out_len;
	245	len -= out_len;
	246	if (len == 0)
	247	break;
	248	} else {
	249	if (!EVP_MAC_final(ctx, mac, NULL))
	250	goto end;
	251	memcpy(out, mac, len);
	252	break;
	253	}
	254	}
	255	ret = 1;
	256	end:
a3c62426 SL	257	if (kmac_buffer != NULL)
	258	OPENSSL_clear_free(kmac_buffer, kmac_out_len);
	259	else
	260	OPENSSL_cleanse(mac_buf, sizeof(mac_buf));
	261
9537fe57 SL	262	EVP_MAC_CTX_free(ctx);
9537fe57 SL	263	EVP_MAC_CTX_free(ctx_init);
9537fe57 SL	264	return ret;
	265	}
	266
	267	static EVP_KDF_IMPL *sskdf_new(void)
	268	{
	269	EVP_KDF_IMPL *impl;
	270
	271	if ((impl = OPENSSL_zalloc(sizeof(*impl))) == NULL)
	272	KDFerr(KDF_F_SSKDF_NEW, ERR_R_MALLOC_FAILURE);
	273	return impl;
	274	}
	275
	276	static void sskdf_reset(EVP_KDF_IMPL *impl)
	277	{
	278	OPENSSL_clear_free(impl->secret, impl->secret_len);
	279	OPENSSL_clear_free(impl->info, impl->info_len);
	280	OPENSSL_clear_free(impl->salt, impl->salt_len);
	281	memset(impl, 0, sizeof(*impl));
	282	}
	283
	284	static void sskdf_free(EVP_KDF_IMPL *impl)
	285	{
	286	sskdf_reset(impl);
	287	OPENSSL_free(impl);
	288	}
	289
	290	static int sskdf_set_buffer(va_list args, unsigned char *out, size_t out_len)
	291	{
	292	const unsigned char *p;
	293	size_t len;
	294
	295	p = va_arg(args, const unsigned char *);
	296	len = va_arg(args, size_t);
	297	if (len == 0 \|\| p == NULL)
	298	return 1;
	299
	300	OPENSSL_free(*out);
	301	*out = OPENSSL_memdup(p, len);
	302	if (*out == NULL)
	303	return 0;
	304
	305	*out_len = len;
	306	return 1;
	307	}
	308
	309	static int sskdf_ctrl(EVP_KDF_IMPL *impl, int cmd, va_list args)
	310	{
	311	const EVP_MD *md;
	312	const EVP_MAC *mac;
	313
	314	switch (cmd) {
	315	case EVP_KDF_CTRL_SET_KEY:
	316	return sskdf_set_buffer(args, &impl->secret, &impl->secret_len);
	317
	318	case EVP_KDF_CTRL_SET_SSKDF_INFO:
	319	return sskdf_set_buffer(args, &impl->info, &impl->info_len);
	320
	321	case EVP_KDF_CTRL_SET_MD:
	322	md = va_arg(args, const EVP_MD *);
	323	if (md == NULL)
	324	return 0;
	325
	326	impl->md = md;
	327	return 1;
328
329	case EVP_KDF_CTRL_SET_MAC:
330	mac = va_arg(args, const EVP_MAC *);
331	if (mac == NULL)
332	return 0;
333
334	impl->mac = mac;
335	return 1;
336
337	case EVP_KDF_CTRL_SET_SALT:
338	return sskdf_set_buffer(args, &impl->salt, &impl->salt_len);
339
340	case EVP_KDF_CTRL_SET_MAC_SIZE:
341	impl->out_len = va_arg(args, size_t);
342	return 1;
343
344	default:
345	return -2;
346	}
347	}
348
349	/* Pass a mac to a ctrl */
350	static int sskdf_mac2ctrl(EVP_KDF_IMPL *impl,
351	int (ctrl)(EVP_KDF_IMPL impl, int cmd, va_list args),
352	int cmd, const char *mac_name)
353	{
354	const EVP_MAC *mac;
355
356	if (mac_name == NULL \|\| (mac = EVP_get_macbyname(mac_name)) == NULL) {
357	KDFerr(KDF_F_SSKDF_MAC2CTRL, KDF_R_INVALID_MAC_TYPE);
358	return 0;
359	}
360	return call_ctrl(ctrl, impl, cmd, mac);
361	}
362
363	static int sskdf_ctrl_str(EVP_KDF_IMPL impl, const char type,
364	const char *value)
365	{
366	if (strcmp(type, "secret") == 0 \|\| strcmp(type, "key") == 0)
367	return kdf_str2ctrl(impl, sskdf_ctrl, EVP_KDF_CTRL_SET_KEY,
368	value);
369
370	if (strcmp(type, "hexsecret") == 0 \|\| strcmp(type, "hexkey") == 0)
371	return kdf_hex2ctrl(impl, sskdf_ctrl, EVP_KDF_CTRL_SET_KEY,
372	value);
373
374	if (strcmp(type, "info") == 0)
375	return kdf_str2ctrl(impl, sskdf_ctrl, EVP_KDF_CTRL_SET_SSKDF_INFO,
376	value);
377
378	if (strcmp(type, "hexinfo") == 0)
379	return kdf_hex2ctrl(impl, sskdf_ctrl, EVP_KDF_CTRL_SET_SSKDF_INFO,
380	value);
381
382	if (strcmp(type, "digest") == 0)
383	return kdf_md2ctrl(impl, sskdf_ctrl, EVP_KDF_CTRL_SET_MD, value);
384
385	if (strcmp(type, "mac") == 0)
386	return sskdf_mac2ctrl(impl, sskdf_ctrl, EVP_KDF_CTRL_SET_MAC, value);
387
388	if (strcmp(type, "salt") == 0)
389	return kdf_str2ctrl(impl, sskdf_ctrl, EVP_KDF_CTRL_SET_SALT, value);
390
391	if (strcmp(type, "hexsalt") == 0)
392	return kdf_hex2ctrl(impl, sskdf_ctrl, EVP_KDF_CTRL_SET_SALT, value);
393
394
395	if (strcmp(type, "maclen") == 0) {
396	int val = atoi(value);
397	if (val < 0) {
398	KDFerr(KDF_F_SSKDF_CTRL_STR, KDF_R_VALUE_ERROR);
399	return 0;
400	}
401	return call_ctrl(sskdf_ctrl, impl, EVP_KDF_CTRL_SET_MAC_SIZE,
402	(size_t)val);
403	}
404	return -2;
405	}
406
407	static size_t sskdf_size(EVP_KDF_IMPL *impl)
408	{
409	int len;
410
411	if (impl->md == NULL) {
412	KDFerr(KDF_F_SSKDF_SIZE, KDF_R_MISSING_MESSAGE_DIGEST);
413	return 0;
414	}
415	len = EVP_MD_size(impl->md);
416	return (len <= 0) ? 0 : (size_t)len;
417	}
418
419	static int sskdf_derive(EVP_KDF_IMPL impl, unsigned char key, size_t keylen)
420	{
421	if (impl->secret == NULL) {
422	KDFerr(KDF_F_SSKDF_DERIVE, KDF_R_MISSING_SECRET);
423	return 0;
424	}
425
426	if (impl->mac != NULL) {
427	/* H(x) = KMAC or H(x) = HMAC */
428	int ret;
429	const unsigned char *custom = NULL;
430	size_t custom_len = 0;
431	int nid;
432	int default_salt_len;
433
434	nid = EVP_MAC_nid(impl->mac);
435	if (nid == EVP_MAC_HMAC) {
436	/* H(x) = HMAC(x, salt, hash) */
437	if (impl->md == NULL) {
438	KDFerr(KDF_F_SSKDF_DERIVE, KDF_R_MISSING_MESSAGE_DIGEST);
439	return 0;
440	}
441	default_salt_len = EVP_MD_block_size(impl->md);
442	if (default_salt_len <= 0)
443	return 0;
444	} else if (nid == EVP_MAC_KMAC128 \|\| nid == EVP_MAC_KMAC256) {
445	/* H(x) = KMACzzz(x, salt, custom) */
446	custom = kmac_custom_str;
447	custom_len = sizeof(kmac_custom_str);
448	if (nid == EVP_MAC_KMAC128)
449	default_salt_len = SSKDF_KMAC128_DEFAULT_SALT_SIZE;
450	else
451	default_salt_len = SSKDF_KMAC256_DEFAULT_SALT_SIZE;
452	} else {
453	KDFerr(KDF_F_SSKDF_DERIVE, KDF_R_UNSUPPORTED_MAC_TYPE);
454	return 0;
455	}
456	/* If no salt is set then use a default_salt of zeros */
457	if (impl->salt == NULL \|\| impl->salt_len <= 0) {
458	impl->salt = OPENSSL_zalloc(default_salt_len);
459	if (impl->salt == NULL) {
460	KDFerr(KDF_F_SSKDF_DERIVE, ERR_R_MALLOC_FAILURE);
461	return 0;
462	}
463	impl->salt_len = default_salt_len;
464	}
465	ret = SSKDF_mac_kdm(impl->mac, impl->md,
466	custom, custom_len, impl->out_len,
467	impl->salt, impl->salt_len,
468	impl->secret, impl->secret_len,
469	impl->info, impl->info_len, key, keylen);
470	return ret;
471	} else {
472	/* H(x) = hash */
473	if (impl->md == NULL) {
474	KDFerr(KDF_F_SSKDF_DERIVE, KDF_R_MISSING_MESSAGE_DIGEST);
475	return 0;
476	}
477	return SSKDF_hash_kdm(impl->md, impl->secret, impl->secret_len,
8bbeaaa4 SL	478	impl->info, impl->info_len, 0, key, keylen);
	479	}
	480	}
	481
	482	static int x963kdf_derive(EVP_KDF_IMPL impl, unsigned char key, size_t keylen)
	483	{
	484	if (impl->secret == NULL) {
	485	KDFerr(KDF_F_X963KDF_DERIVE, KDF_R_MISSING_SECRET);
	486	return 0;
	487	}
	488
	489	if (impl->mac != NULL) {
	490	KDFerr(KDF_F_X963KDF_DERIVE, KDF_R_NOT_SUPPORTED);
	491	return 0;
	492	} else {
	493	/* H(x) = hash */
	494	if (impl->md == NULL) {
	495	KDFerr(KDF_F_X963KDF_DERIVE, KDF_R_MISSING_MESSAGE_DIGEST);
	496	return 0;
	497	}
	498	return SSKDF_hash_kdm(impl->md, impl->secret, impl->secret_len,
	499	impl->info, impl->info_len, 1, key, keylen);
9537fe57 SL	500	}
	501	}
	502
d2ba8123	503	const EVP_KDF ss_kdf_meth = {
9537fe57 SL	504	EVP_KDF_SS,
	505	sskdf_new,
	506	sskdf_free,
	507	sskdf_reset,
	508	sskdf_ctrl,
	509	sskdf_ctrl_str,
	510	sskdf_size,
	511	sskdf_derive
	512	};
8bbeaaa4 SL	513
	514	const EVP_KDF x963_kdf_meth = {
	515	EVP_KDF_X963,
	516	sskdf_new,
	517	sskdf_free,
	518	sskdf_reset,
	519	sskdf_ctrl,
	520	sskdf_ctrl_str,
	521	sskdf_size,
	522	x963kdf_derive
	523	};