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

Source
/*
 * Copyright 2018-2025 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"
#include "providers/implementations/kdfs/sshkdf.inc"

/* 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[])
{
    struct sshkdf_set_ctx_params_st p;
    KDF_SSHKDF *ctx = vctx;
    OSSL_LIB_CTX *provctx;

    if (ctx == NULL || !sshkdf_set_ctx_params_decoder(params, &p))
        return 0;

    provctx = PROV_LIBCTX_OF(ctx->provctx);

    if (!OSSL_FIPS_IND_SET_CTX_FROM_PARAM(ctx, OSSL_FIPS_IND_SETTABLE0, p.ind_d))
        return 0;
    if (!OSSL_FIPS_IND_SET_CTX_FROM_PARAM(ctx, OSSL_FIPS_IND_SETTABLE1, p.ind_k))
        return 0;

    if (p.digest != NULL) {
        const EVP_MD *md = NULL;

        if (!ossl_prov_digest_load(&ctx->digest, p.digest,
                                   p.propq, p.engine, 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.key != NULL) {
        if (!sshkdf_set_membuf(&ctx->key, &ctx->key_len, p.key))
            return 0;

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

    if (p.xcg != NULL
            && !sshkdf_set_membuf(&ctx->xcghash, &ctx->xcghash_len, p.xcg))
        return 0;

    if (p.sid != NULL
            && !sshkdf_set_membuf(&ctx->session_id, &ctx->session_id_len, p.sid))
        return 0;

    if (p.type != NULL) {
        const char *kdftype;

        if (!OSSL_PARAM_get_utf8_string_ptr(p.type, &kdftype))
            return 0;
        /* Expect one character (byte in this case) */
        if (kdftype == NULL || p.type->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)
{
    return sshkdf_set_ctx_params_list;
}

static int kdf_sshkdf_get_ctx_params(void *vctx, OSSL_PARAM params[])
{
    KDF_SSHKDF *ctx = (KDF_SSHKDF *)vctx;
    struct sshkdf_get_ctx_params_st p;

    if (ctx == NULL || !sshkdf_get_ctx_params_decoder(params, &p))
        return 0;

    if (p.size != NULL && !OSSL_PARAM_set_size_t(p.size, SIZE_MAX))
        return 0;

    if (!OSSL_FIPS_IND_GET_CTX_FROM_PARAM(ctx, p.ind))
        return 0;
    return 1;
}

static const OSSL_PARAM *kdf_sshkdf_gettable_ctx_params(ossl_unused void *ctx,
                                                        ossl_unused void *p_ctx)
{
    return sshkdf_get_ctx_params_list;
}

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: 2025-10-28 06:56

Line	Count	Source
1		/*
2		* Copyright 2018-2025 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		#include "providers/implementations/kdfs/sshkdf.inc"
26
27		/* See RFC 4253, Section 7.2 */
28		static OSSL_FUNC_kdf_newctx_fn kdf_sshkdf_new;
29		static OSSL_FUNC_kdf_dupctx_fn kdf_sshkdf_dup;
30		static OSSL_FUNC_kdf_freectx_fn kdf_sshkdf_free;
31		static OSSL_FUNC_kdf_reset_fn kdf_sshkdf_reset;
32		static OSSL_FUNC_kdf_derive_fn kdf_sshkdf_derive;
33		static OSSL_FUNC_kdf_settable_ctx_params_fn kdf_sshkdf_settable_ctx_params;
34		static OSSL_FUNC_kdf_set_ctx_params_fn kdf_sshkdf_set_ctx_params;
35		static OSSL_FUNC_kdf_gettable_ctx_params_fn kdf_sshkdf_gettable_ctx_params;
36		static OSSL_FUNC_kdf_get_ctx_params_fn kdf_sshkdf_get_ctx_params;
37
38		static int SSHKDF(const EVP_MD *evp_md,
39		const unsigned char *key, size_t key_len,
40		const unsigned char *xcghash, size_t xcghash_len,
41		const unsigned char *session_id, size_t session_id_len,
42		char type, unsigned char *okey, size_t okey_len);
43
44		typedef struct {
45		void *provctx;
46		PROV_DIGEST digest;
47		unsigned char key; / K */
48		size_t key_len;
49		unsigned char xcghash; / H */
50		size_t xcghash_len;
51		char type; /* X */
52		unsigned char *session_id;
53		size_t session_id_len;
54		OSSL_FIPS_IND_DECLARE
55		} KDF_SSHKDF;
56
57		static void kdf_sshkdf_new(void provctx)
58	0	{
59	0	KDF_SSHKDF *ctx;
60
61	0	if (!ossl_prov_is_running())
62	0	return NULL;
63
64	0	if ((ctx = OPENSSL_zalloc(sizeof(*ctx))) != NULL) {
65	0	ctx->provctx = provctx;
66	0	OSSL_FIPS_IND_INIT(ctx)
67	0	}
68	0	return ctx;
69	0	}
70
71		static void kdf_sshkdf_free(void *vctx)
72	0	{
73	0	KDF_SSHKDF ctx = (KDF_SSHKDF )vctx;
74
75	0	if (ctx != NULL) {
76	0	kdf_sshkdf_reset(ctx);
77	0	OPENSSL_free(ctx);
78	0	}
79	0	}
80
81		static void kdf_sshkdf_reset(void *vctx)
82	0	{
83	0	KDF_SSHKDF ctx = (KDF_SSHKDF )vctx;
84	0	void *provctx = ctx->provctx;
85
86	0	ossl_prov_digest_reset(&ctx->digest);
87	0	OPENSSL_clear_free(ctx->key, ctx->key_len);
88	0	OPENSSL_clear_free(ctx->xcghash, ctx->xcghash_len);
89	0	OPENSSL_clear_free(ctx->session_id, ctx->session_id_len);
90	0	memset(ctx, 0, sizeof(*ctx));
91	0	ctx->provctx = provctx;
92	0	}
93
94		static void kdf_sshkdf_dup(void vctx)
95	0	{
96	0	const KDF_SSHKDF src = (const KDF_SSHKDF )vctx;
97	0	KDF_SSHKDF *dest;
98
99	0	dest = kdf_sshkdf_new(src->provctx);
100	0	if (dest != NULL) {
101	0	if (!ossl_prov_memdup(src->key, src->key_len,
102	0	&dest->key, &dest->key_len)
103	0	\|\| !ossl_prov_memdup(src->xcghash, src->xcghash_len,
104	0	&dest->xcghash , &dest->xcghash_len)
105	0	\|\| !ossl_prov_memdup(src->session_id, src->session_id_len,
106	0	&dest->session_id , &dest->session_id_len)
107	0	\|\| !ossl_prov_digest_copy(&dest->digest, &src->digest))
108	0	goto err;
109	0	dest->type = src->type;
110	0	OSSL_FIPS_IND_COPY(dest, src)
111	0	}
112	0	return dest;
113
114	0	err:
115	0	kdf_sshkdf_free(dest);
116	0	return NULL;
117	0	}
118
119		static int sshkdf_set_membuf(unsigned char *dst, size_t dst_len,
120		const OSSL_PARAM *p)
121	0	{
122	0	OPENSSL_clear_free(dst, dst_len);
123	0	*dst = NULL;
124	0	*dst_len = 0;
125	0	return OSSL_PARAM_get_octet_string(p, (void **)dst, 0, dst_len);
126	0	}
127
128		#ifdef FIPS_MODULE
129		static int fips_digest_check_passed(KDF_SSHKDF ctx, const EVP_MD md)
130		{
131		OSSL_LIB_CTX *libctx = PROV_LIBCTX_OF(ctx->provctx);
132		/*
133		* Perform digest check
134		*
135		* According to NIST SP 800-135r1 section 5.2, the valid hash functions are
136		* specified in FIPS 180-3. ACVP also only lists the same set of hash
137		* functions.
138		*/
139		int digest_unapproved = !EVP_MD_is_a(md, SN_sha1)
140		&& !EVP_MD_is_a(md, SN_sha224)
141		&& !EVP_MD_is_a(md, SN_sha256)
142		&& !EVP_MD_is_a(md, SN_sha384)
143		&& !EVP_MD_is_a(md, SN_sha512);
144
145		if (digest_unapproved) {
146		if (!OSSL_FIPS_IND_ON_UNAPPROVED(ctx, OSSL_FIPS_IND_SETTABLE0,
147		libctx, "SSHKDF", "Digest",
148		ossl_fips_config_sshkdf_digest_check)) {
149		ERR_raise(ERR_LIB_PROV, PROV_R_DIGEST_NOT_ALLOWED);
150		return 0;
151		}
152		}
153		return 1;
154		}
155
156		static int fips_key_check_passed(KDF_SSHKDF *ctx)
157		{
158		OSSL_LIB_CTX *libctx = PROV_LIBCTX_OF(ctx->provctx);
159		int key_approved = ossl_kdf_check_key_size(ctx->key_len);
160
161		if (!key_approved) {
162		if (!OSSL_FIPS_IND_ON_UNAPPROVED(ctx, OSSL_FIPS_IND_SETTABLE1,
163		libctx, "SSHKDF", "Key size",
164		ossl_fips_config_sshkdf_key_check)) {
165		ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_KEY_LENGTH);
166		return 0;
167		}
168		}
169		return 1;
170		}
171		#endif
172
173		static int kdf_sshkdf_derive(void vctx, unsigned char key, size_t keylen,
174		const OSSL_PARAM params[])
175	0	{
176	0	KDF_SSHKDF ctx = (KDF_SSHKDF )vctx;
177	0	const EVP_MD *md;
178
179	0	if (!ossl_prov_is_running() \|\| !kdf_sshkdf_set_ctx_params(ctx, params))
180	0	return 0;
181
182	0	md = ossl_prov_digest_md(&ctx->digest);
183	0	if (md == NULL) {
184	0	ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MESSAGE_DIGEST);
185	0	return 0;
186	0	}
187	0	if (ctx->key == NULL) {
188	0	ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_KEY);
189	0	return 0;
190	0	}
191	0	if (ctx->xcghash == NULL) {
192	0	ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_XCGHASH);
193	0	return 0;
194	0	}
195	0	if (ctx->session_id == NULL) {
196	0	ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_SESSION_ID);
197	0	return 0;
198	0	}
199	0	if (ctx->type == 0) {
200	0	ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_TYPE);
201	0	return 0;
202	0	}
203
204	0	return SSHKDF(md, ctx->key, ctx->key_len,
205	0	ctx->xcghash, ctx->xcghash_len,
206	0	ctx->session_id, ctx->session_id_len,
207	0	ctx->type, key, keylen);
208	0	}
209
210		static int kdf_sshkdf_set_ctx_params(void *vctx, const OSSL_PARAM params[])
211	0	{
212	0	struct sshkdf_set_ctx_params_st p;
213	0	KDF_SSHKDF *ctx = vctx;
214	0	OSSL_LIB_CTX *provctx;
215
216	0	if (ctx == NULL \|\| !sshkdf_set_ctx_params_decoder(params, &p))
217	0	return 0;
218
219	0	provctx = PROV_LIBCTX_OF(ctx->provctx);
220
221	0	if (!OSSL_FIPS_IND_SET_CTX_FROM_PARAM(ctx, OSSL_FIPS_IND_SETTABLE0, p.ind_d))
222	0	return 0;
223	0	if (!OSSL_FIPS_IND_SET_CTX_FROM_PARAM(ctx, OSSL_FIPS_IND_SETTABLE1, p.ind_k))
224	0	return 0;
225
226	0	if (p.digest != NULL) {
227	0	const EVP_MD *md = NULL;
228
229	0	if (!ossl_prov_digest_load(&ctx->digest, p.digest,
230	0	p.propq, p.engine, provctx))
231	0	return 0;
232
233	0	md = ossl_prov_digest_md(&ctx->digest);
234	0	if (EVP_MD_xof(md)) {
235	0	ERR_raise(ERR_LIB_PROV, PROV_R_XOF_DIGESTS_NOT_ALLOWED);
236	0	return 0;
237	0	}
238
239		#ifdef FIPS_MODULE
240		if (!fips_digest_check_passed(ctx, md))
241		return 0;
242		#endif
243	0	}
244
245	0	if (p.key != NULL) {
246	0	if (!sshkdf_set_membuf(&ctx->key, &ctx->key_len, p.key))
247	0	return 0;
248
249		#ifdef FIPS_MODULE
250		if (!fips_key_check_passed(ctx))
251		return 0;
252		#endif
253	0	}
254
255	0	if (p.xcg != NULL
256	0	&& !sshkdf_set_membuf(&ctx->xcghash, &ctx->xcghash_len, p.xcg))
257	0	return 0;
258
259	0	if (p.sid != NULL
260	0	&& !sshkdf_set_membuf(&ctx->session_id, &ctx->session_id_len, p.sid))
261	0	return 0;
262
263	0	if (p.type != NULL) {
264	0	const char *kdftype;
265
266	0	if (!OSSL_PARAM_get_utf8_string_ptr(p.type, &kdftype))
267	0	return 0;
268		/* Expect one character (byte in this case) */
269	0	if (kdftype == NULL \|\| p.type->data_size != 1)
270	0	return 0;
271	0	if (kdftype[0] < 65 \|\| kdftype[0] > 70) {
272	0	ERR_raise(ERR_LIB_PROV, PROV_R_VALUE_ERROR);
273	0	return 0;
274	0	}
275	0	ctx->type = kdftype[0];
276	0	}
277	0	return 1;
278	0	}
279
280		static const OSSL_PARAM kdf_sshkdf_settable_ctx_params(ossl_unused void ctx,
281		ossl_unused void *p_ctx)
282	0	{
283	0	return sshkdf_set_ctx_params_list;
284	0	}
285
286		static int kdf_sshkdf_get_ctx_params(void *vctx, OSSL_PARAM params[])
287	0	{
288	0	KDF_SSHKDF ctx = (KDF_SSHKDF )vctx;
289	0	struct sshkdf_get_ctx_params_st p;
290
291	0	if (ctx == NULL \|\| !sshkdf_get_ctx_params_decoder(params, &p))
292	0	return 0;
293
294	0	if (p.size != NULL && !OSSL_PARAM_set_size_t(p.size, SIZE_MAX))
295	0	return 0;
296
297	0	if (!OSSL_FIPS_IND_GET_CTX_FROM_PARAM(ctx, p.ind))
298	0	return 0;
299	0	return 1;
300	0	}
301
302		static const OSSL_PARAM kdf_sshkdf_gettable_ctx_params(ossl_unused void ctx,
303		ossl_unused void *p_ctx)
304	0	{
305	0	return sshkdf_get_ctx_params_list;
306	0	}
307
308		const OSSL_DISPATCH ossl_kdf_sshkdf_functions[] = {
309		{ OSSL_FUNC_KDF_NEWCTX, (void(*)(void))kdf_sshkdf_new },
310		{ OSSL_FUNC_KDF_DUPCTX, (void(*)(void))kdf_sshkdf_dup },
311		{ OSSL_FUNC_KDF_FREECTX, (void(*)(void))kdf_sshkdf_free },
312		{ OSSL_FUNC_KDF_RESET, (void(*)(void))kdf_sshkdf_reset },
313		{ OSSL_FUNC_KDF_DERIVE, (void(*)(void))kdf_sshkdf_derive },
314		{ OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS,
315		(void(*)(void))kdf_sshkdf_settable_ctx_params },
316		{ OSSL_FUNC_KDF_SET_CTX_PARAMS, (void(*)(void))kdf_sshkdf_set_ctx_params },
317		{ OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS,
318		(void(*)(void))kdf_sshkdf_gettable_ctx_params },
319		{ OSSL_FUNC_KDF_GET_CTX_PARAMS, (void(*)(void))kdf_sshkdf_get_ctx_params },
320		OSSL_DISPATCH_END
321		};
322
323		static int SSHKDF(const EVP_MD *evp_md,
324		const unsigned char *key, size_t key_len,
325		const unsigned char *xcghash, size_t xcghash_len,
326		const unsigned char *session_id, size_t session_id_len,
327		char type, unsigned char *okey, size_t okey_len)
328	0	{
329	0	EVP_MD_CTX *md = NULL;
330	0	unsigned char digest[EVP_MAX_MD_SIZE];
331	0	unsigned int dsize = 0;
332	0	size_t cursize = 0;
333	0	int ret = 0;
334
335	0	md = EVP_MD_CTX_new();
336	0	if (md == NULL)
337	0	return 0;
338
339	0	if (!EVP_DigestInit_ex(md, evp_md, NULL))
340	0	goto out;
341
342	0	if (!EVP_DigestUpdate(md, key, key_len))
343	0	goto out;
344
345	0	if (!EVP_DigestUpdate(md, xcghash, xcghash_len))
346	0	goto out;
347
348	0	if (!EVP_DigestUpdate(md, &type, 1))
349	0	goto out;
350
351	0	if (!EVP_DigestUpdate(md, session_id, session_id_len))
352	0	goto out;
353
354	0	if (!EVP_DigestFinal_ex(md, digest, &dsize))
355	0	goto out;
356
357	0	if (okey_len < dsize) {
358	0	memcpy(okey, digest, okey_len);
359	0	ret = 1;
360	0	goto out;
361	0	}
362
363	0	memcpy(okey, digest, dsize);
364
365	0	for (cursize = dsize; cursize < okey_len; cursize += dsize) {
366
367	0	if (!EVP_DigestInit_ex(md, evp_md, NULL))
368	0	goto out;
369
370	0	if (!EVP_DigestUpdate(md, key, key_len))
371	0	goto out;
372
373	0	if (!EVP_DigestUpdate(md, xcghash, xcghash_len))
374	0	goto out;
375
376	0	if (!EVP_DigestUpdate(md, okey, cursize))
377	0	goto out;
378
379	0	if (!EVP_DigestFinal_ex(md, digest, &dsize))
380	0	goto out;
381
382	0	if (okey_len < cursize + dsize) {
383	0	memcpy(okey + cursize, digest, okey_len - cursize);
384	0	ret = 1;
385	0	goto out;
386	0	}
387
388	0	memcpy(okey + cursize, digest, dsize);
389	0	}
390
391	0	ret = 1;
392
393	0	out:
394	0	EVP_MD_CTX_free(md);
395	0	OPENSSL_cleanse(digest, EVP_MAX_MD_SIZE);
396	0	return ret;
397	0	}