/src/openssl/providers/implementations/kdfs/sshkdf.c

Source (jump to first uncovered line)
/*
 * Copyright 2018-2024 The OpenSSL Project Authors. 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
 */

#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <openssl/evp.h>
#include <openssl/kdf.h>
#include <openssl/core_names.h>
#include <openssl/proverr.h>
#include "internal/cryptlib.h"
#include "internal/numbers.h"
#include "crypto/evp.h"
#include "prov/provider_ctx.h"
#include "prov/providercommon.h"
#include "prov/implementations.h"
#include "prov/provider_util.h"
#include "prov/securitycheck.h"

/* See RFC 4253, Section 7.2 */
static OSSL_FUNC_kdf_newctx_fn kdf_sshkdf_new;
static OSSL_FUNC_kdf_dupctx_fn kdf_sshkdf_dup;
static OSSL_FUNC_kdf_freectx_fn kdf_sshkdf_free;
static OSSL_FUNC_kdf_reset_fn kdf_sshkdf_reset;
static OSSL_FUNC_kdf_derive_fn kdf_sshkdf_derive;
static OSSL_FUNC_kdf_settable_ctx_params_fn kdf_sshkdf_settable_ctx_params;
static OSSL_FUNC_kdf_set_ctx_params_fn kdf_sshkdf_set_ctx_params;
static OSSL_FUNC_kdf_gettable_ctx_params_fn kdf_sshkdf_gettable_ctx_params;
static OSSL_FUNC_kdf_get_ctx_params_fn kdf_sshkdf_get_ctx_params;

static int SSHKDF(const EVP_MD *evp_md,
                  const unsigned char *key, size_t key_len,
                  const unsigned char *xcghash, size_t xcghash_len,
                  const unsigned char *session_id, size_t session_id_len,
                  char type, unsigned char *okey, size_t okey_len);

typedef struct {
    void *provctx;
    PROV_DIGEST digest;
    unsigned char *key; /* K */
    size_t key_len;
    unsigned char *xcghash; /* H */
    size_t xcghash_len;
    char type; /* X */
    unsigned char *session_id;
    size_t session_id_len;
    OSSL_FIPS_IND_DECLARE
} KDF_SSHKDF;

static void *kdf_sshkdf_new(void *provctx)
{
    KDF_SSHKDF *ctx;

    if (!ossl_prov_is_running())
        return NULL;

    if ((ctx = OPENSSL_zalloc(sizeof(*ctx))) != NULL) {
        ctx->provctx = provctx;
        OSSL_FIPS_IND_INIT(ctx)
    }
    return ctx;
}

static void kdf_sshkdf_free(void *vctx)
{
    KDF_SSHKDF *ctx = (KDF_SSHKDF *)vctx;

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

static void kdf_sshkdf_reset(void *vctx)
{
    KDF_SSHKDF *ctx = (KDF_SSHKDF *)vctx;
    void *provctx = ctx->provctx;

    ossl_prov_digest_reset(&ctx->digest);
    OPENSSL_clear_free(ctx->key, ctx->key_len);
    OPENSSL_clear_free(ctx->xcghash, ctx->xcghash_len);
    OPENSSL_clear_free(ctx->session_id, ctx->session_id_len);
    memset(ctx, 0, sizeof(*ctx));
    ctx->provctx = provctx;
}

static void *kdf_sshkdf_dup(void *vctx)
{
    const KDF_SSHKDF *src = (const KDF_SSHKDF *)vctx;
    KDF_SSHKDF *dest;

    dest = kdf_sshkdf_new(src->provctx);
    if (dest != NULL) {
        if (!ossl_prov_memdup(src->key, src->key_len,
                              &dest->key, &dest->key_len)
                || !ossl_prov_memdup(src->xcghash, src->xcghash_len,
                                     &dest->xcghash , &dest->xcghash_len)
                || !ossl_prov_memdup(src->session_id, src->session_id_len,
                                     &dest->session_id , &dest->session_id_len)
                || !ossl_prov_digest_copy(&dest->digest, &src->digest))
            goto err;
        dest->type = src->type;
        OSSL_FIPS_IND_COPY(dest, src)
    }
    return dest;

 err:
    kdf_sshkdf_free(dest);
    return NULL;
}

static int sshkdf_set_membuf(unsigned char **dst, size_t *dst_len,
                             const OSSL_PARAM *p)
{
    OPENSSL_clear_free(*dst, *dst_len);
    *dst = NULL;
    *dst_len = 0;
    return OSSL_PARAM_get_octet_string(p, (void **)dst, 0, dst_len);
}

#ifdef FIPS_MODULE
static int fips_digest_check_passed(KDF_SSHKDF *ctx, const EVP_MD *md)
{
    OSSL_LIB_CTX *libctx = PROV_LIBCTX_OF(ctx->provctx);
    /*
     * Perform digest check
     *
     * According to NIST SP 800-135r1 section 5.2, the valid hash functions are
     * specified in FIPS 180-3. ACVP also only lists the same set of hash
     * functions.
     */
    int digest_unapproved = !EVP_MD_is_a(md, SN_sha1)
        && !EVP_MD_is_a(md, SN_sha224)
        && !EVP_MD_is_a(md, SN_sha256)
        && !EVP_MD_is_a(md, SN_sha384)
        && !EVP_MD_is_a(md, SN_sha512);

    if (digest_unapproved) {
        if (!OSSL_FIPS_IND_ON_UNAPPROVED(ctx, OSSL_FIPS_IND_SETTABLE0,
                                         libctx, "SSHKDF", "Digest",
                                         ossl_fips_config_sshkdf_digest_check)) {
            ERR_raise(ERR_LIB_PROV, PROV_R_DIGEST_NOT_ALLOWED);
            return 0;
        }
    }
    return 1;
}

static int fips_key_check_passed(KDF_SSHKDF *ctx)
{
    OSSL_LIB_CTX *libctx = PROV_LIBCTX_OF(ctx->provctx);
    int key_approved = ossl_kdf_check_key_size(ctx->key_len);

    if (!key_approved) {
        if (!OSSL_FIPS_IND_ON_UNAPPROVED(ctx, OSSL_FIPS_IND_SETTABLE1,
                                         libctx, "SSHKDF", "Key size",
                                         ossl_fips_config_sshkdf_key_check)) {
            ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH);
            return 0;
        }
    }
    return 1;
}
#endif

static int kdf_sshkdf_derive(void *vctx, unsigned char *key, size_t keylen,
                             const OSSL_PARAM params[])
{
    KDF_SSHKDF *ctx = (KDF_SSHKDF *)vctx;
    const EVP_MD *md;

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

    md = ossl_prov_digest_md(&ctx->digest);
    if (md == NULL) {
        ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MESSAGE_DIGEST);
        return 0;
    }
    if (ctx->key == NULL) {
        ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_KEY);
        return 0;
    }
    if (ctx->xcghash == NULL) {
        ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_XCGHASH);
        return 0;
    }
    if (ctx->session_id == NULL) {
        ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_SESSION_ID);
        return 0;
    }
    if (ctx->type == 0) {
        ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_TYPE);
        return 0;
    }

    return SSHKDF(md, ctx->key, ctx->key_len,
                  ctx->xcghash, ctx->xcghash_len,
                  ctx->session_id, ctx->session_id_len,
                  ctx->type, key, keylen);
}

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

    if (ossl_param_is_empty(params))
        return 1;

    if (!OSSL_FIPS_IND_SET_CTX_PARAM(ctx, OSSL_FIPS_IND_SETTABLE0, params,
                                     OSSL_KDF_PARAM_FIPS_DIGEST_CHECK))
        return 0;
    if (!OSSL_FIPS_IND_SET_CTX_PARAM(ctx, OSSL_FIPS_IND_SETTABLE1, params,
                                     OSSL_KDF_PARAM_FIPS_KEY_CHECK))
        return 0;

    if (OSSL_PARAM_locate_const(params, OSSL_ALG_PARAM_DIGEST) != NULL) {
        const EVP_MD *md = NULL;

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

        md = ossl_prov_digest_md(&ctx->digest);
        if (EVP_MD_xof(md)) {
            ERR_raise(ERR_LIB_PROV, PROV_R_XOF_DIGESTS_NOT_ALLOWED);
            return 0;
        }

#ifdef FIPS_MODULE
        if (!fips_digest_check_passed(ctx, md))
            return 0;
#endif
    }

    if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_KEY)) != NULL) {
        if (!sshkdf_set_membuf(&ctx->key, &ctx->key_len, p))
            return 0;

#ifdef FIPS_MODULE
        if (!fips_key_check_passed(ctx))
            return 0;
#endif
    }

    if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SSHKDF_XCGHASH))
        != NULL)
        if (!sshkdf_set_membuf(&ctx->xcghash, &ctx->xcghash_len, p))
            return 0;

    if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SSHKDF_SESSION_ID))
        != NULL)
        if (!sshkdf_set_membuf(&ctx->session_id, &ctx->session_id_len, p))
            return 0;

    if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SSHKDF_TYPE))
        != NULL) {
        const char *kdftype;

        if (!OSSL_PARAM_get_utf8_string_ptr(p, &kdftype))
            return 0;
        /* Expect one character (byte in this case) */
        if (kdftype == NULL || p->data_size != 1)
            return 0;
        if (kdftype[0] < 65 || kdftype[0] > 70) {
            ERR_raise(ERR_LIB_PROV, PROV_R_VALUE_ERROR);
            return 0;
        }
        ctx->type = kdftype[0];
    }
    return 1;
}

static const OSSL_PARAM *kdf_sshkdf_settable_ctx_params(ossl_unused void *ctx,
                                                        ossl_unused void *p_ctx)
{
    static const OSSL_PARAM known_settable_ctx_params[] = {
        OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_PROPERTIES, NULL, 0),
        OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_DIGEST, NULL, 0),
        OSSL_PARAM_octet_string(OSSL_KDF_PARAM_KEY, NULL, 0),
        OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SSHKDF_XCGHASH, NULL, 0),
        OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SSHKDF_SESSION_ID, NULL, 0),
        OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_SSHKDF_TYPE, NULL, 0),
        OSSL_FIPS_IND_SETTABLE_CTX_PARAM(OSSL_KDF_PARAM_FIPS_DIGEST_CHECK)
        OSSL_FIPS_IND_SETTABLE_CTX_PARAM(OSSL_KDF_PARAM_FIPS_KEY_CHECK)
        OSSL_PARAM_END
    };
    return known_settable_ctx_params;
}

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

    if ((p = OSSL_PARAM_locate(params, OSSL_KDF_PARAM_SIZE)) != NULL) {
        if (!OSSL_PARAM_set_size_t(p, SIZE_MAX))
            return 0;
    }
    if (!OSSL_FIPS_IND_GET_CTX_PARAM(((KDF_SSHKDF *)vctx), params))
        return 0;
    return 1;
}

static const OSSL_PARAM *kdf_sshkdf_gettable_ctx_params(ossl_unused void *ctx,
                                                        ossl_unused void *p_ctx)
{
    static const OSSL_PARAM known_gettable_ctx_params[] = {
        OSSL_PARAM_size_t(OSSL_KDF_PARAM_SIZE, NULL),
        OSSL_FIPS_IND_GETTABLE_CTX_PARAM()
        OSSL_PARAM_END
    };
    return known_gettable_ctx_params;
}

const OSSL_DISPATCH ossl_kdf_sshkdf_functions[] = {
    { OSSL_FUNC_KDF_NEWCTX, (void(*)(void))kdf_sshkdf_new },
    { OSSL_FUNC_KDF_DUPCTX, (void(*)(void))kdf_sshkdf_dup },
    { OSSL_FUNC_KDF_FREECTX, (void(*)(void))kdf_sshkdf_free },
    { OSSL_FUNC_KDF_RESET, (void(*)(void))kdf_sshkdf_reset },
    { OSSL_FUNC_KDF_DERIVE, (void(*)(void))kdf_sshkdf_derive },
    { OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS,
      (void(*)(void))kdf_sshkdf_settable_ctx_params },
    { OSSL_FUNC_KDF_SET_CTX_PARAMS, (void(*)(void))kdf_sshkdf_set_ctx_params },
    { OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS,
      (void(*)(void))kdf_sshkdf_gettable_ctx_params },
    { OSSL_FUNC_KDF_GET_CTX_PARAMS, (void(*)(void))kdf_sshkdf_get_ctx_params },
    OSSL_DISPATCH_END
};

static int SSHKDF(const EVP_MD *evp_md,
                  const unsigned char *key, size_t key_len,
                  const unsigned char *xcghash, size_t xcghash_len,
                  const unsigned char *session_id, size_t session_id_len,
                  char type, unsigned char *okey, size_t okey_len)
{
    EVP_MD_CTX *md = NULL;
    unsigned char digest[EVP_MAX_MD_SIZE];
    unsigned int dsize = 0;
    size_t cursize = 0;
    int ret = 0;

    md = EVP_MD_CTX_new();
    if (md == NULL)
        return 0;

    if (!EVP_DigestInit_ex(md, evp_md, NULL))
        goto out;

    if (!EVP_DigestUpdate(md, key, key_len))
        goto out;

    if (!EVP_DigestUpdate(md, xcghash, xcghash_len))
        goto out;

    if (!EVP_DigestUpdate(md, &type, 1))
        goto out;

    if (!EVP_DigestUpdate(md, session_id, session_id_len))
        goto out;

    if (!EVP_DigestFinal_ex(md, digest, &dsize))
        goto out;

    if (okey_len < dsize) {
        memcpy(okey, digest, okey_len);
        ret = 1;
        goto out;
    }

    memcpy(okey, digest, dsize);

    for (cursize = dsize; cursize < okey_len; cursize += dsize) {

        if (!EVP_DigestInit_ex(md, evp_md, NULL))
            goto out;

        if (!EVP_DigestUpdate(md, key, key_len))
            goto out;

        if (!EVP_DigestUpdate(md, xcghash, xcghash_len))
            goto out;

        if (!EVP_DigestUpdate(md, okey, cursize))
            goto out;

        if (!EVP_DigestFinal_ex(md, digest, &dsize))
            goto out;

        if (okey_len < cursize + dsize) {
            memcpy(okey + cursize, digest, okey_len - cursize);
            ret = 1;
            goto out;
        }

        memcpy(okey + cursize, digest, dsize);
    }

    ret = 1;

out:
    EVP_MD_CTX_free(md);
    OPENSSL_cleanse(digest, EVP_MAX_MD_SIZE);
    return ret;
}

Coverage Report

Created: 2025-06-13 06:55

Line	Count	Source (jump to first uncovered line)
1		/*
2		* Copyright 2018-2024 The OpenSSL Project Authors. All Rights Reserved.
3		*
4		* Licensed under the Apache License 2.0 (the "License"). You may not use
5		* this file except in compliance with the License. You can obtain a copy
6		* in the file LICENSE in the source distribution or at
7		* https://www.openssl.org/source/license.html
8		*/
9
10		#include <stdlib.h>
11		#include <stdarg.h>
12		#include <string.h>
13		#include <openssl/evp.h>
14		#include <openssl/kdf.h>
15		#include <openssl/core_names.h>
16		#include <openssl/proverr.h>
17		#include "internal/cryptlib.h"
18		#include "internal/numbers.h"
19		#include "crypto/evp.h"
20		#include "prov/provider_ctx.h"
21		#include "prov/providercommon.h"
22		#include "prov/implementations.h"
23		#include "prov/provider_util.h"
24		#include "prov/securitycheck.h"
25
26		/* See RFC 4253, Section 7.2 */
27		static OSSL_FUNC_kdf_newctx_fn kdf_sshkdf_new;
28		static OSSL_FUNC_kdf_dupctx_fn kdf_sshkdf_dup;
29		static OSSL_FUNC_kdf_freectx_fn kdf_sshkdf_free;
30		static OSSL_FUNC_kdf_reset_fn kdf_sshkdf_reset;
31		static OSSL_FUNC_kdf_derive_fn kdf_sshkdf_derive;
32		static OSSL_FUNC_kdf_settable_ctx_params_fn kdf_sshkdf_settable_ctx_params;
33		static OSSL_FUNC_kdf_set_ctx_params_fn kdf_sshkdf_set_ctx_params;
34		static OSSL_FUNC_kdf_gettable_ctx_params_fn kdf_sshkdf_gettable_ctx_params;
35		static OSSL_FUNC_kdf_get_ctx_params_fn kdf_sshkdf_get_ctx_params;
36
37		static int SSHKDF(const EVP_MD *evp_md,
38		const unsigned char *key, size_t key_len,
39		const unsigned char *xcghash, size_t xcghash_len,
40		const unsigned char *session_id, size_t session_id_len,
41		char type, unsigned char *okey, size_t okey_len);
42
43		typedef struct {
44		void *provctx;
45		PROV_DIGEST digest;
46		unsigned char key; / K */
47		size_t key_len;
48		unsigned char xcghash; / H */
49		size_t xcghash_len;
50		char type; /* X */
51		unsigned char *session_id;
52		size_t session_id_len;
53		OSSL_FIPS_IND_DECLARE
54		} KDF_SSHKDF;
55
56		static void kdf_sshkdf_new(void provctx)
57	0	{
58	0	KDF_SSHKDF *ctx;
59
60	0	if (!ossl_prov_is_running())
61	0	return NULL;
62
63	0	if ((ctx = OPENSSL_zalloc(sizeof(*ctx))) != NULL) {
64	0	ctx->provctx = provctx;
65	0	OSSL_FIPS_IND_INIT(ctx)
66	0	}
67	0	return ctx;
68	0	}
69
70		static void kdf_sshkdf_free(void *vctx)
71	0	{
72	0	KDF_SSHKDF ctx = (KDF_SSHKDF )vctx;
73
74	0	if (ctx != NULL) {
75	0	kdf_sshkdf_reset(ctx);
76	0	OPENSSL_free(ctx);
77	0	}
78	0	}
79
80		static void kdf_sshkdf_reset(void *vctx)
81	0	{
82	0	KDF_SSHKDF ctx = (KDF_SSHKDF )vctx;
83	0	void *provctx = ctx->provctx;
84
85	0	ossl_prov_digest_reset(&ctx->digest);
86	0	OPENSSL_clear_free(ctx->key, ctx->key_len);
87	0	OPENSSL_clear_free(ctx->xcghash, ctx->xcghash_len);
88	0	OPENSSL_clear_free(ctx->session_id, ctx->session_id_len);
89	0	memset(ctx, 0, sizeof(*ctx));
90	0	ctx->provctx = provctx;
91	0	}
92
93		static void kdf_sshkdf_dup(void vctx)
94	0	{
95	0	const KDF_SSHKDF src = (const KDF_SSHKDF )vctx;
96	0	KDF_SSHKDF *dest;
97
98	0	dest = kdf_sshkdf_new(src->provctx);
99	0	if (dest != NULL) {
100	0	if (!ossl_prov_memdup(src->key, src->key_len,
101	0	&dest->key, &dest->key_len)
102	0	\|\| !ossl_prov_memdup(src->xcghash, src->xcghash_len,
103	0	&dest->xcghash , &dest->xcghash_len)
104	0	\|\| !ossl_prov_memdup(src->session_id, src->session_id_len,
105	0	&dest->session_id , &dest->session_id_len)
106	0	\|\| !ossl_prov_digest_copy(&dest->digest, &src->digest))
107	0	goto err;
108	0	dest->type = src->type;
109	0	OSSL_FIPS_IND_COPY(dest, src)
110	0	}
111	0	return dest;
112
113	0	err:
114	0	kdf_sshkdf_free(dest);
115	0	return NULL;
116	0	}
117
118		static int sshkdf_set_membuf(unsigned char *dst, size_t dst_len,
119		const OSSL_PARAM *p)
120	0	{
121	0	OPENSSL_clear_free(dst, dst_len);
122	0	*dst = NULL;
123	0	*dst_len = 0;
124	0	return OSSL_PARAM_get_octet_string(p, (void **)dst, 0, dst_len);
125	0	}
126
127		#ifdef FIPS_MODULE
128		static int fips_digest_check_passed(KDF_SSHKDF ctx, const EVP_MD md)
129		{
130		OSSL_LIB_CTX *libctx = PROV_LIBCTX_OF(ctx->provctx);
131		/*
132		* Perform digest check
133		*
134		* According to NIST SP 800-135r1 section 5.2, the valid hash functions are
135		* specified in FIPS 180-3. ACVP also only lists the same set of hash
136		* functions.
137		*/
138		int digest_unapproved = !EVP_MD_is_a(md, SN_sha1)
139		&& !EVP_MD_is_a(md, SN_sha224)
140		&& !EVP_MD_is_a(md, SN_sha256)
141		&& !EVP_MD_is_a(md, SN_sha384)
142		&& !EVP_MD_is_a(md, SN_sha512);
143
144		if (digest_unapproved) {
145		if (!OSSL_FIPS_IND_ON_UNAPPROVED(ctx, OSSL_FIPS_IND_SETTABLE0,
146		libctx, "SSHKDF", "Digest",
147		ossl_fips_config_sshkdf_digest_check)) {
148		ERR_raise(ERR_LIB_PROV, PROV_R_DIGEST_NOT_ALLOWED);
149		return 0;
150		}
151		}
152		return 1;
153		}
154
155		static int fips_key_check_passed(KDF_SSHKDF *ctx)
156		{
157		OSSL_LIB_CTX *libctx = PROV_LIBCTX_OF(ctx->provctx);
158		int key_approved = ossl_kdf_check_key_size(ctx->key_len);
159
160		if (!key_approved) {
161		if (!OSSL_FIPS_IND_ON_UNAPPROVED(ctx, OSSL_FIPS_IND_SETTABLE1,
162		libctx, "SSHKDF", "Key size",
163		ossl_fips_config_sshkdf_key_check)) {
164		ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH);
165		return 0;
166		}
167		}
168		return 1;
169		}
170		#endif
171
172		static int kdf_sshkdf_derive(void vctx, unsigned char key, size_t keylen,
173		const OSSL_PARAM params[])
174	0	{
175	0	KDF_SSHKDF ctx = (KDF_SSHKDF )vctx;
176	0	const EVP_MD *md;
177
178	0	if (!ossl_prov_is_running() \|\| !kdf_sshkdf_set_ctx_params(ctx, params))
179	0	return 0;
180
181	0	md = ossl_prov_digest_md(&ctx->digest);
182	0	if (md == NULL) {
183	0	ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MESSAGE_DIGEST);
184	0	return 0;
185	0	}
186	0	if (ctx->key == NULL) {
187	0	ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_KEY);
188	0	return 0;
189	0	}
190	0	if (ctx->xcghash == NULL) {
191	0	ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_XCGHASH);
192	0	return 0;
193	0	}
194	0	if (ctx->session_id == NULL) {
195	0	ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_SESSION_ID);
196	0	return 0;
197	0	}
198	0	if (ctx->type == 0) {
199	0	ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_TYPE);
200	0	return 0;
201	0	}
202
203	0	return SSHKDF(md, ctx->key, ctx->key_len,
204	0	ctx->xcghash, ctx->xcghash_len,
205	0	ctx->session_id, ctx->session_id_len,
206	0	ctx->type, key, keylen);
207	0	}
208
209		static int kdf_sshkdf_set_ctx_params(void *vctx, const OSSL_PARAM params[])
210	0	{
211	0	const OSSL_PARAM *p;
212	0	KDF_SSHKDF *ctx = vctx;
213	0	OSSL_LIB_CTX *provctx = PROV_LIBCTX_OF(ctx->provctx);
214
215	0	if (ossl_param_is_empty(params))
216	0	return 1;
217
218	0	if (!OSSL_FIPS_IND_SET_CTX_PARAM(ctx, OSSL_FIPS_IND_SETTABLE0, params,
219	0	OSSL_KDF_PARAM_FIPS_DIGEST_CHECK))
220	0	return 0;
221	0	if (!OSSL_FIPS_IND_SET_CTX_PARAM(ctx, OSSL_FIPS_IND_SETTABLE1, params,
222	0	OSSL_KDF_PARAM_FIPS_KEY_CHECK))
223	0	return 0;
224
225	0	if (OSSL_PARAM_locate_const(params, OSSL_ALG_PARAM_DIGEST) != NULL) {
226	0	const EVP_MD *md = NULL;
227
228	0	if (!ossl_prov_digest_load_from_params(&ctx->digest, params, provctx))
229	0	return 0;
230
231	0	md = ossl_prov_digest_md(&ctx->digest);
232	0	if (EVP_MD_xof(md)) {
233	0	ERR_raise(ERR_LIB_PROV, PROV_R_XOF_DIGESTS_NOT_ALLOWED);
234	0	return 0;
235	0	}
236
237		#ifdef FIPS_MODULE
238		if (!fips_digest_check_passed(ctx, md))
239		return 0;
240		#endif
241	0	}
242
243	0	if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_KEY)) != NULL) {
244	0	if (!sshkdf_set_membuf(&ctx->key, &ctx->key_len, p))
245	0	return 0;
246
247		#ifdef FIPS_MODULE
248		if (!fips_key_check_passed(ctx))
249		return 0;
250		#endif
251	0	}
252
253	0	if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SSHKDF_XCGHASH))
254	0	!= NULL)
255	0	if (!sshkdf_set_membuf(&ctx->xcghash, &ctx->xcghash_len, p))
256	0	return 0;
257
258	0	if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SSHKDF_SESSION_ID))
259	0	!= NULL)
260	0	if (!sshkdf_set_membuf(&ctx->session_id, &ctx->session_id_len, p))
261	0	return 0;
262
263	0	if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SSHKDF_TYPE))
264	0	!= NULL) {
265	0	const char *kdftype;
266
267	0	if (!OSSL_PARAM_get_utf8_string_ptr(p, &kdftype))
268	0	return 0;
269		/* Expect one character (byte in this case) */
270	0	if (kdftype == NULL \|\| p->data_size != 1)
271	0	return 0;
272	0	if (kdftype[0] < 65 \|\| kdftype[0] > 70) {
273	0	ERR_raise(ERR_LIB_PROV, PROV_R_VALUE_ERROR);
274	0	return 0;
275	0	}
276	0	ctx->type = kdftype[0];
277	0	}
278	0	return 1;
279	0	}
280
281		static const OSSL_PARAM kdf_sshkdf_settable_ctx_params(ossl_unused void ctx,
282		ossl_unused void *p_ctx)
283	0	{
284	0	static const OSSL_PARAM known_settable_ctx_params[] = {
285	0	OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_PROPERTIES, NULL, 0),
286	0	OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_DIGEST, NULL, 0),
287	0	OSSL_PARAM_octet_string(OSSL_KDF_PARAM_KEY, NULL, 0),
288	0	OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SSHKDF_XCGHASH, NULL, 0),
289	0	OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SSHKDF_SESSION_ID, NULL, 0),
290	0	OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_SSHKDF_TYPE, NULL, 0),
291	0	OSSL_FIPS_IND_SETTABLE_CTX_PARAM(OSSL_KDF_PARAM_FIPS_DIGEST_CHECK)
292	0	OSSL_FIPS_IND_SETTABLE_CTX_PARAM(OSSL_KDF_PARAM_FIPS_KEY_CHECK)
293	0	OSSL_PARAM_END
294	0	};
295	0	return known_settable_ctx_params;
296	0	}
297
298		static int kdf_sshkdf_get_ctx_params(void *vctx, OSSL_PARAM params[])
299	0	{
300	0	OSSL_PARAM *p;
301
302	0	if ((p = OSSL_PARAM_locate(params, OSSL_KDF_PARAM_SIZE)) != NULL) {
303	0	if (!OSSL_PARAM_set_size_t(p, SIZE_MAX))
304	0	return 0;
305	0	}
306	0	if (!OSSL_FIPS_IND_GET_CTX_PARAM(((KDF_SSHKDF *)vctx), params))
307	0	return 0;
308	0	return 1;
309	0	}
310
311		static const OSSL_PARAM kdf_sshkdf_gettable_ctx_params(ossl_unused void ctx,
312		ossl_unused void *p_ctx)
313	0	{
314	0	static const OSSL_PARAM known_gettable_ctx_params[] = {
315	0	OSSL_PARAM_size_t(OSSL_KDF_PARAM_SIZE, NULL),
316	0	OSSL_FIPS_IND_GETTABLE_CTX_PARAM()
317	0	OSSL_PARAM_END
318	0	};
319	0	return known_gettable_ctx_params;
320	0	}
321
322		const OSSL_DISPATCH ossl_kdf_sshkdf_functions[] = {
323		{ OSSL_FUNC_KDF_NEWCTX, (void(*)(void))kdf_sshkdf_new },
324		{ OSSL_FUNC_KDF_DUPCTX, (void(*)(void))kdf_sshkdf_dup },
325		{ OSSL_FUNC_KDF_FREECTX, (void(*)(void))kdf_sshkdf_free },
326		{ OSSL_FUNC_KDF_RESET, (void(*)(void))kdf_sshkdf_reset },
327		{ OSSL_FUNC_KDF_DERIVE, (void(*)(void))kdf_sshkdf_derive },
328		{ OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS,
329		(void(*)(void))kdf_sshkdf_settable_ctx_params },
330		{ OSSL_FUNC_KDF_SET_CTX_PARAMS, (void(*)(void))kdf_sshkdf_set_ctx_params },
331		{ OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS,
332		(void(*)(void))kdf_sshkdf_gettable_ctx_params },
333		{ OSSL_FUNC_KDF_GET_CTX_PARAMS, (void(*)(void))kdf_sshkdf_get_ctx_params },
334		OSSL_DISPATCH_END
335		};
336
337		static int SSHKDF(const EVP_MD *evp_md,
338		const unsigned char *key, size_t key_len,
339		const unsigned char *xcghash, size_t xcghash_len,
340		const unsigned char *session_id, size_t session_id_len,
341		char type, unsigned char *okey, size_t okey_len)
342	0	{
343	0	EVP_MD_CTX *md = NULL;
344	0	unsigned char digest[EVP_MAX_MD_SIZE];
345	0	unsigned int dsize = 0;
346	0	size_t cursize = 0;
347	0	int ret = 0;
348
349	0	md = EVP_MD_CTX_new();
350	0	if (md == NULL)
351	0	return 0;
352
353	0	if (!EVP_DigestInit_ex(md, evp_md, NULL))
354	0	goto out;
355
356	0	if (!EVP_DigestUpdate(md, key, key_len))
357	0	goto out;
358
359	0	if (!EVP_DigestUpdate(md, xcghash, xcghash_len))
360	0	goto out;
361
362	0	if (!EVP_DigestUpdate(md, &type, 1))
363	0	goto out;
364
365	0	if (!EVP_DigestUpdate(md, session_id, session_id_len))
366	0	goto out;
367
368	0	if (!EVP_DigestFinal_ex(md, digest, &dsize))
369	0	goto out;
370
371	0	if (okey_len < dsize) {
372	0	memcpy(okey, digest, okey_len);
373	0	ret = 1;
374	0	goto out;
375	0	}
376
377	0	memcpy(okey, digest, dsize);
378
379	0	for (cursize = dsize; cursize < okey_len; cursize += dsize) {
380
381	0	if (!EVP_DigestInit_ex(md, evp_md, NULL))
382	0	goto out;
383
384	0	if (!EVP_DigestUpdate(md, key, key_len))
385	0	goto out;
386
387	0	if (!EVP_DigestUpdate(md, xcghash, xcghash_len))
388	0	goto out;
389
390	0	if (!EVP_DigestUpdate(md, okey, cursize))
391	0	goto out;
392
393	0	if (!EVP_DigestFinal_ex(md, digest, &dsize))
394	0	goto out;
395
396	0	if (okey_len < cursize + dsize) {
397	0	memcpy(okey + cursize, digest, okey_len - cursize);
398	0	ret = 1;
399	0	goto out;
400	0	}
401
402	0	memcpy(okey + cursize, digest, dsize);
403	0	}
404
405	0	ret = 1;
406
407	0	out:
408	0	EVP_MD_CTX_free(md);
409	0	OPENSSL_cleanse(digest, EVP_MAX_MD_SIZE);
410	0	return ret;
411	0	}