[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_init = EVP_MAC_CTX_new(kdf_mac);
    if (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);

        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))
                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;
        }
        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 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.
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>
	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
9537fe57	205	ctx_init = EVP_MAC_CTX_new(kdf_mac);
be5fc053	206	if (ctx_init == NULL)
9537fe57 SL	207	goto end;
9537fe57 SL	208	if (hmac_md != NULL &&
17838470	209	EVP_MAC_ctrl(ctx_init, EVP_MAC_CTRL_SET_MD, hmac_md) <= 0)
9537fe57 SL	210	goto end;
9537fe57 SL	211
17838470	212	if (EVP_MAC_ctrl(ctx_init, EVP_MAC_CTRL_SET_KEY, salt, salt_len) <= 0)
9537fe57 SL	213	goto end;
	214
	215	if (!kmac_init(ctx_init, kmac_custom, kmac_custom_len, kmac_out_len,
	216	derived_key_len, &kmac_buffer))
	217	goto end;
	218	if (kmac_buffer != NULL)
	219	mac = kmac_buffer;
	220
	221	if (!EVP_MAC_init(ctx_init))
	222	goto end;
	223
	224	out_len = EVP_MAC_size(ctx_init); /* output size */
	225	if (out_len <= 0)
	226	goto end;
	227	len = derived_key_len;
	228
	229	for (counter = 1;; counter++) {
	230	c[0] = (unsigned char)((counter >> 24) & 0xff);
	231	c[1] = (unsigned char)((counter >> 16) & 0xff);
	232	c[2] = (unsigned char)((counter >> 8) & 0xff);
	233	c[3] = (unsigned char)(counter & 0xff);
	234
be5fc053 KR	235	ctx = EVP_MAC_CTX_dup(ctx_init);
be5fc053 KR	236	if (!(ctx != NULL
9537fe57 SL	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	}
be5fc053 KR	254	EVP_MAC_CTX_free(ctx);
be5fc053 KR	255	ctx = NULL;
9537fe57 SL	256	}
	257	ret = 1;
	258	end:
a3c62426 SL	259	if (kmac_buffer != NULL)
	260	OPENSSL_clear_free(kmac_buffer, kmac_out_len);
	261	else
	262	OPENSSL_cleanse(mac_buf, sizeof(mac_buf));
	263
9537fe57 SL	264	EVP_MAC_CTX_free(ctx);
9537fe57 SL	265	EVP_MAC_CTX_free(ctx_init);
9537fe57 SL	266	return ret;
	267	}
	268
	269	static EVP_KDF_IMPL *sskdf_new(void)
	270	{
	271	EVP_KDF_IMPL *impl;
	272
	273	if ((impl = OPENSSL_zalloc(sizeof(*impl))) == NULL)
	274	KDFerr(KDF_F_SSKDF_NEW, ERR_R_MALLOC_FAILURE);
	275	return impl;
	276	}
	277
	278	static void sskdf_reset(EVP_KDF_IMPL *impl)
	279	{
	280	OPENSSL_clear_free(impl->secret, impl->secret_len);
	281	OPENSSL_clear_free(impl->info, impl->info_len);
	282	OPENSSL_clear_free(impl->salt, impl->salt_len);
	283	memset(impl, 0, sizeof(*impl));
	284	}
	285
	286	static void sskdf_free(EVP_KDF_IMPL *impl)
	287	{
	288	sskdf_reset(impl);
	289	OPENSSL_free(impl);
	290	}
	291
	292	static int sskdf_set_buffer(va_list args, unsigned char *out, size_t out_len)
	293	{
	294	const unsigned char *p;
	295	size_t len;
	296
	297	p = va_arg(args, const unsigned char *);
	298	len = va_arg(args, size_t);
	299	if (len == 0 \|\| p == NULL)
	300	return 1;
	301
	302	OPENSSL_free(*out);
	303	*out = OPENSSL_memdup(p, len);
	304	if (*out == NULL)
	305	return 0;
	306
	307	*out_len = len;
	308	return 1;
	309	}
	310
	311	static int sskdf_ctrl(EVP_KDF_IMPL *impl, int cmd, va_list args)
	312	{
	313	const EVP_MD *md;
	314	const EVP_MAC *mac;
	315
	316	switch (cmd) {
	317	case EVP_KDF_CTRL_SET_KEY:
	318	return sskdf_set_buffer(args, &impl->secret, &impl->secret_len);
	319
	320	case EVP_KDF_CTRL_SET_SSKDF_INFO:
	321	return sskdf_set_buffer(args, &impl->info, &impl->info_len);
	322
	323	case EVP_KDF_CTRL_SET_MD:
	324	md = va_arg(args, const EVP_MD *);
	325	if (md == NULL)
	326	return 0;
	327
	328	impl->md = md;
	329	return 1;
330
331	case EVP_KDF_CTRL_SET_MAC:
332	mac = va_arg(args, const EVP_MAC *);
333	if (mac == NULL)
334	return 0;
335
336	impl->mac = mac;
337	return 1;
338
339	case EVP_KDF_CTRL_SET_SALT:
340	return sskdf_set_buffer(args, &impl->salt, &impl->salt_len);
341
342	case EVP_KDF_CTRL_SET_MAC_SIZE:
343	impl->out_len = va_arg(args, size_t);
344	return 1;
345
346	default:
347	return -2;
348	}
349	}
350
351	/* Pass a mac to a ctrl */
352	static int sskdf_mac2ctrl(EVP_KDF_IMPL *impl,
353	int (ctrl)(EVP_KDF_IMPL impl, int cmd, va_list args),
354	int cmd, const char *mac_name)
355	{
356	const EVP_MAC *mac;
357
358	if (mac_name == NULL \|\| (mac = EVP_get_macbyname(mac_name)) == NULL) {
359	KDFerr(KDF_F_SSKDF_MAC2CTRL, KDF_R_INVALID_MAC_TYPE);
360	return 0;
361	}
362	return call_ctrl(ctrl, impl, cmd, mac);
363	}
364
365	static int sskdf_ctrl_str(EVP_KDF_IMPL impl, const char type,
366	const char *value)
367	{
368	if (strcmp(type, "secret") == 0 \|\| strcmp(type, "key") == 0)
369	return kdf_str2ctrl(impl, sskdf_ctrl, EVP_KDF_CTRL_SET_KEY,
370	value);
371
372	if (strcmp(type, "hexsecret") == 0 \|\| strcmp(type, "hexkey") == 0)
373	return kdf_hex2ctrl(impl, sskdf_ctrl, EVP_KDF_CTRL_SET_KEY,
374	value);
375
376	if (strcmp(type, "info") == 0)
377	return kdf_str2ctrl(impl, sskdf_ctrl, EVP_KDF_CTRL_SET_SSKDF_INFO,
378	value);
379
380	if (strcmp(type, "hexinfo") == 0)
381	return kdf_hex2ctrl(impl, sskdf_ctrl, EVP_KDF_CTRL_SET_SSKDF_INFO,
382	value);
383
384	if (strcmp(type, "digest") == 0)
385	return kdf_md2ctrl(impl, sskdf_ctrl, EVP_KDF_CTRL_SET_MD, value);
386
387	if (strcmp(type, "mac") == 0)
388	return sskdf_mac2ctrl(impl, sskdf_ctrl, EVP_KDF_CTRL_SET_MAC, value);
389
390	if (strcmp(type, "salt") == 0)
391	return kdf_str2ctrl(impl, sskdf_ctrl, EVP_KDF_CTRL_SET_SALT, value);
392
393	if (strcmp(type, "hexsalt") == 0)
394	return kdf_hex2ctrl(impl, sskdf_ctrl, EVP_KDF_CTRL_SET_SALT, value);
395
396
397	if (strcmp(type, "maclen") == 0) {
398	int val = atoi(value);
399	if (val < 0) {
400	KDFerr(KDF_F_SSKDF_CTRL_STR, KDF_R_VALUE_ERROR);
401	return 0;
402	}
403	return call_ctrl(sskdf_ctrl, impl, EVP_KDF_CTRL_SET_MAC_SIZE,
404	(size_t)val);
405	}
406	return -2;
407	}
408
409	static size_t sskdf_size(EVP_KDF_IMPL *impl)
410	{
411	int len;
412
413	if (impl->md == NULL) {
414	KDFerr(KDF_F_SSKDF_SIZE, KDF_R_MISSING_MESSAGE_DIGEST);
415	return 0;
416	}
417	len = EVP_MD_size(impl->md);
418	return (len <= 0) ? 0 : (size_t)len;
419	}
420
421	static int sskdf_derive(EVP_KDF_IMPL impl, unsigned char key, size_t keylen)
422	{
423	if (impl->secret == NULL) {
424	KDFerr(KDF_F_SSKDF_DERIVE, KDF_R_MISSING_SECRET);
425	return 0;
426	}
427
428	if (impl->mac != NULL) {
429	/* H(x) = KMAC or H(x) = HMAC */
430	int ret;
431	const unsigned char *custom = NULL;
432	size_t custom_len = 0;
433	int nid;
434	int default_salt_len;
435
436	nid = EVP_MAC_nid(impl->mac);
437	if (nid == EVP_MAC_HMAC) {
438	/* H(x) = HMAC(x, salt, hash) */
439	if (impl->md == NULL) {
440	KDFerr(KDF_F_SSKDF_DERIVE, KDF_R_MISSING_MESSAGE_DIGEST);
441	return 0;
442	}
443	default_salt_len = EVP_MD_block_size(impl->md);
444	if (default_salt_len <= 0)
445	return 0;
446	} else if (nid == EVP_MAC_KMAC128 \|\| nid == EVP_MAC_KMAC256) {
447	/* H(x) = KMACzzz(x, salt, custom) */
448	custom = kmac_custom_str;
449	custom_len = sizeof(kmac_custom_str);
450	if (nid == EVP_MAC_KMAC128)
451	default_salt_len = SSKDF_KMAC128_DEFAULT_SALT_SIZE;
452	else
453	default_salt_len = SSKDF_KMAC256_DEFAULT_SALT_SIZE;
454	} else {
455	KDFerr(KDF_F_SSKDF_DERIVE, KDF_R_UNSUPPORTED_MAC_TYPE);
456	return 0;
457	}
458	/* If no salt is set then use a default_salt of zeros */
459	if (impl->salt == NULL \|\| impl->salt_len <= 0) {
460	impl->salt = OPENSSL_zalloc(default_salt_len);
461	if (impl->salt == NULL) {
462	KDFerr(KDF_F_SSKDF_DERIVE, ERR_R_MALLOC_FAILURE);
463	return 0;
464	}
465	impl->salt_len = default_salt_len;
466	}
467	ret = SSKDF_mac_kdm(impl->mac, impl->md,
468	custom, custom_len, impl->out_len,
469	impl->salt, impl->salt_len,
470	impl->secret, impl->secret_len,
471	impl->info, impl->info_len, key, keylen);
472	return ret;
473	} else {
474	/* H(x) = hash */
475	if (impl->md == NULL) {
476	KDFerr(KDF_F_SSKDF_DERIVE, KDF_R_MISSING_MESSAGE_DIGEST);
477	return 0;
478	}
479	return SSKDF_hash_kdm(impl->md, impl->secret, impl->secret_len,
8bbeaaa4 SL	480	impl->info, impl->info_len, 0, key, keylen);
	481	}
	482	}
	483
	484	static int x963kdf_derive(EVP_KDF_IMPL impl, unsigned char key, size_t keylen)
	485	{
	486	if (impl->secret == NULL) {
	487	KDFerr(KDF_F_X963KDF_DERIVE, KDF_R_MISSING_SECRET);
	488	return 0;
	489	}
	490
	491	if (impl->mac != NULL) {
	492	KDFerr(KDF_F_X963KDF_DERIVE, KDF_R_NOT_SUPPORTED);
	493	return 0;
	494	} else {
	495	/* H(x) = hash */
	496	if (impl->md == NULL) {
	497	KDFerr(KDF_F_X963KDF_DERIVE, KDF_R_MISSING_MESSAGE_DIGEST);
	498	return 0;
	499	}
	500	return SSKDF_hash_kdm(impl->md, impl->secret, impl->secret_len,
	501	impl->info, impl->info_len, 1, key, keylen);
9537fe57 SL	502	}
	503	}
	504
d2ba8123	505	const EVP_KDF ss_kdf_meth = {
9537fe57 SL	506	EVP_KDF_SS,
	507	sskdf_new,
	508	sskdf_free,
	509	sskdf_reset,
	510	sskdf_ctrl,
	511	sskdf_ctrl_str,
	512	sskdf_size,
	513	sskdf_derive
	514	};
8bbeaaa4 SL	515
	516	const EVP_KDF x963_kdf_meth = {
	517	EVP_KDF_X963,
	518	sskdf_new,
	519	sskdf_free,
	520	sskdf_reset,
	521	sskdf_ctrl,
	522	sskdf_ctrl_str,
	523	sskdf_size,
	524	x963kdf_derive
	525	};