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

Source (jump to first uncovered line)
/*
 * Copyright 2018-2023 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 "prov/fipscommon.h"
#include "prov/fipsindicator.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",
                                         FIPS_sshkdf_digest_check)) {
            ERR_raise(ERR_LIB_PROV, PROV_R_DIGEST_NOT_ALLOWED);
            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 (params == NULL)
        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_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_get_flags(md) & EVP_MD_FLAG_XOF) != 0) {
            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;

    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_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: 2024-07-27 06:35

Line	Count	Source (jump to first uncovered line)
1		/*
2		* Copyright 2018-2023 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 "prov/fipscommon.h"
26		#include "prov/fipsindicator.h"
27
28		/* See RFC 4253, Section 7.2 */
29		static OSSL_FUNC_kdf_newctx_fn kdf_sshkdf_new;
30		static OSSL_FUNC_kdf_dupctx_fn kdf_sshkdf_dup;
31		static OSSL_FUNC_kdf_freectx_fn kdf_sshkdf_free;
32		static OSSL_FUNC_kdf_reset_fn kdf_sshkdf_reset;
33		static OSSL_FUNC_kdf_derive_fn kdf_sshkdf_derive;
34		static OSSL_FUNC_kdf_settable_ctx_params_fn kdf_sshkdf_settable_ctx_params;
35		static OSSL_FUNC_kdf_set_ctx_params_fn kdf_sshkdf_set_ctx_params;
36		static OSSL_FUNC_kdf_gettable_ctx_params_fn kdf_sshkdf_gettable_ctx_params;
37		static OSSL_FUNC_kdf_get_ctx_params_fn kdf_sshkdf_get_ctx_params;
38
39		static int SSHKDF(const EVP_MD *evp_md,
40		const unsigned char *key, size_t key_len,
41		const unsigned char *xcghash, size_t xcghash_len,
42		const unsigned char *session_id, size_t session_id_len,
43		char type, unsigned char *okey, size_t okey_len);
44
45		typedef struct {
46		void *provctx;
47		PROV_DIGEST digest;
48		unsigned char key; / K */
49		size_t key_len;
50		unsigned char xcghash; / H */
51		size_t xcghash_len;
52		char type; /* X */
53		unsigned char *session_id;
54		size_t session_id_len;
55		OSSL_FIPS_IND_DECLARE
56		} KDF_SSHKDF;
57
58		static void kdf_sshkdf_new(void provctx)
59	0	{
60	0	KDF_SSHKDF *ctx;
61
62	0	if (!ossl_prov_is_running())
63	0	return NULL;
64
65	0	if ((ctx = OPENSSL_zalloc(sizeof(*ctx))) != NULL) {
66	0	ctx->provctx = provctx;
67	0	OSSL_FIPS_IND_INIT(ctx)
68	0	}
69	0	return ctx;
70	0	}
71
72		static void kdf_sshkdf_free(void *vctx)
73	0	{
74	0	KDF_SSHKDF ctx = (KDF_SSHKDF )vctx;
75
76	0	if (ctx != NULL) {
77	0	kdf_sshkdf_reset(ctx);
78	0	OPENSSL_free(ctx);
79	0	}
80	0	}
81
82		static void kdf_sshkdf_reset(void *vctx)
83	0	{
84	0	KDF_SSHKDF ctx = (KDF_SSHKDF )vctx;
85	0	void *provctx = ctx->provctx;
86
87	0	ossl_prov_digest_reset(&ctx->digest);
88	0	OPENSSL_clear_free(ctx->key, ctx->key_len);
89	0	OPENSSL_clear_free(ctx->xcghash, ctx->xcghash_len);
90	0	OPENSSL_clear_free(ctx->session_id, ctx->session_id_len);
91	0	memset(ctx, 0, sizeof(*ctx));
92	0	ctx->provctx = provctx;
93	0	}
94
95		static void kdf_sshkdf_dup(void vctx)
96	0	{
97	0	const KDF_SSHKDF src = (const KDF_SSHKDF )vctx;
98	0	KDF_SSHKDF *dest;
99
100	0	dest = kdf_sshkdf_new(src->provctx);
101	0	if (dest != NULL) {
102	0	if (!ossl_prov_memdup(src->key, src->key_len,
103	0	&dest->key, &dest->key_len)
104	0	\|\| !ossl_prov_memdup(src->xcghash, src->xcghash_len,
105	0	&dest->xcghash , &dest->xcghash_len)
106	0	\|\| !ossl_prov_memdup(src->session_id, src->session_id_len,
107	0	&dest->session_id , &dest->session_id_len)
108	0	\|\| !ossl_prov_digest_copy(&dest->digest, &src->digest))
109	0	goto err;
110	0	dest->type = src->type;
111	0	OSSL_FIPS_IND_COPY(dest, src)
112	0	}
113	0	return dest;
114
115	0	err:
116	0	kdf_sshkdf_free(dest);
117	0	return NULL;
118	0	}
119
120		static int sshkdf_set_membuf(unsigned char *dst, size_t dst_len,
121		const OSSL_PARAM *p)
122	0	{
123	0	OPENSSL_clear_free(dst, dst_len);
124	0	*dst = NULL;
125	0	*dst_len = 0;
126	0	return OSSL_PARAM_get_octet_string(p, (void **)dst, 0, dst_len);
127	0	}
128
129		#ifdef FIPS_MODULE
130		static int fips_digest_check_passed(KDF_SSHKDF ctx, const EVP_MD md)
131		{
132		OSSL_LIB_CTX *libctx = PROV_LIBCTX_OF(ctx->provctx);
133		/*
134		* Perform digest check
135		*
136		* According to NIST SP 800-135r1 section 5.2, the valid hash functions are
137		* specified in FIPS 180-3. ACVP also only lists the same set of hash
138		* functions.
139		*/
140		int digest_unapproved = !EVP_MD_is_a(md, SN_sha1)
141		&& !EVP_MD_is_a(md, SN_sha224)
142		&& !EVP_MD_is_a(md, SN_sha256)
143		&& !EVP_MD_is_a(md, SN_sha384)
144		&& !EVP_MD_is_a(md, SN_sha512);
145
146		if (digest_unapproved) {
147		if (!OSSL_FIPS_IND_ON_UNAPPROVED(ctx, OSSL_FIPS_IND_SETTABLE0,
148		libctx, "SSHKDF", "Digest",
149		FIPS_sshkdf_digest_check)) {
150		ERR_raise(ERR_LIB_PROV, PROV_R_DIGEST_NOT_ALLOWED);
151		return 0;
152		}
153		}
154		return 1;
155		}
156		#endif
157
158		static int kdf_sshkdf_derive(void vctx, unsigned char key, size_t keylen,
159		const OSSL_PARAM params[])
160	0	{
161	0	KDF_SSHKDF ctx = (KDF_SSHKDF )vctx;
162	0	const EVP_MD *md;
163
164	0	if (!ossl_prov_is_running() \|\| !kdf_sshkdf_set_ctx_params(ctx, params))
165	0	return 0;
166
167	0	md = ossl_prov_digest_md(&ctx->digest);
168	0	if (md == NULL) {
169	0	ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_MESSAGE_DIGEST);
170	0	return 0;
171	0	}
172	0	if (ctx->key == NULL) {
173	0	ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_KEY);
174	0	return 0;
175	0	}
176	0	if (ctx->xcghash == NULL) {
177	0	ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_XCGHASH);
178	0	return 0;
179	0	}
180	0	if (ctx->session_id == NULL) {
181	0	ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_SESSION_ID);
182	0	return 0;
183	0	}
184	0	if (ctx->type == 0) {
185	0	ERR_raise(ERR_LIB_PROV, PROV_R_MISSING_TYPE);
186	0	return 0;
187	0	}
188
189	0	return SSHKDF(md, ctx->key, ctx->key_len,
190	0	ctx->xcghash, ctx->xcghash_len,
191	0	ctx->session_id, ctx->session_id_len,
192	0	ctx->type, key, keylen);
193	0	}
194
195		static int kdf_sshkdf_set_ctx_params(void *vctx, const OSSL_PARAM params[])
196	0	{
197	0	const OSSL_PARAM *p;
198	0	KDF_SSHKDF *ctx = vctx;
199	0	OSSL_LIB_CTX *provctx = PROV_LIBCTX_OF(ctx->provctx);
200
201	0	if (params == NULL)
202	0	return 1;
203
204	0	if (!OSSL_FIPS_IND_SET_CTX_PARAM(ctx, OSSL_FIPS_IND_SETTABLE0, params,
205	0	OSSL_KDF_PARAM_FIPS_DIGEST_CHECK))
206	0	return 0;
207
208	0	if (OSSL_PARAM_locate_const(params, OSSL_ALG_PARAM_DIGEST) != NULL) {
209	0	const EVP_MD *md = NULL;
210
211	0	if (!ossl_prov_digest_load_from_params(&ctx->digest, params, provctx))
212	0	return 0;
213
214	0	md = ossl_prov_digest_md(&ctx->digest);
215	0	if ((EVP_MD_get_flags(md) & EVP_MD_FLAG_XOF) != 0) {
216	0	ERR_raise(ERR_LIB_PROV, PROV_R_XOF_DIGESTS_NOT_ALLOWED);
217	0	return 0;
218	0	}
219
220		#ifdef FIPS_MODULE
221		if (!fips_digest_check_passed(ctx, md))
222		return 0;
223		#endif
224	0	}
225
226	0	if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_KEY)) != NULL)
227	0	if (!sshkdf_set_membuf(&ctx->key, &ctx->key_len, p))
228	0	return 0;
229
230	0	if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SSHKDF_XCGHASH))
231	0	!= NULL)
232	0	if (!sshkdf_set_membuf(&ctx->xcghash, &ctx->xcghash_len, p))
233	0	return 0;
234
235	0	if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SSHKDF_SESSION_ID))
236	0	!= NULL)
237	0	if (!sshkdf_set_membuf(&ctx->session_id, &ctx->session_id_len, p))
238	0	return 0;
239
240	0	if ((p = OSSL_PARAM_locate_const(params, OSSL_KDF_PARAM_SSHKDF_TYPE))
241	0	!= NULL) {
242	0	const char *kdftype;
243
244	0	if (!OSSL_PARAM_get_utf8_string_ptr(p, &kdftype))
245	0	return 0;
246		/* Expect one character (byte in this case) */
247	0	if (kdftype == NULL \|\| p->data_size != 1)
248	0	return 0;
249	0	if (kdftype[0] < 65 \|\| kdftype[0] > 70) {
250	0	ERR_raise(ERR_LIB_PROV, PROV_R_VALUE_ERROR);
251	0	return 0;
252	0	}
253	0	ctx->type = kdftype[0];
254	0	}
255	0	return 1;
256	0	}
257
258		static const OSSL_PARAM kdf_sshkdf_settable_ctx_params(ossl_unused void ctx,
259		ossl_unused void *p_ctx)
260	0	{
261	0	static const OSSL_PARAM known_settable_ctx_params[] = {
262	0	OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_PROPERTIES, NULL, 0),
263	0	OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_DIGEST, NULL, 0),
264	0	OSSL_PARAM_octet_string(OSSL_KDF_PARAM_KEY, NULL, 0),
265	0	OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SSHKDF_XCGHASH, NULL, 0),
266	0	OSSL_PARAM_octet_string(OSSL_KDF_PARAM_SSHKDF_SESSION_ID, NULL, 0),
267	0	OSSL_PARAM_utf8_string(OSSL_KDF_PARAM_SSHKDF_TYPE, NULL, 0),
268	0	OSSL_FIPS_IND_SETTABLE_CTX_PARAM(OSSL_KDF_PARAM_FIPS_DIGEST_CHECK)
269	0	OSSL_PARAM_END
270	0	};
271	0	return known_settable_ctx_params;
272	0	}
273
274		static int kdf_sshkdf_get_ctx_params(void *vctx, OSSL_PARAM params[])
275	0	{
276	0	OSSL_PARAM *p;
277
278	0	if ((p = OSSL_PARAM_locate(params, OSSL_KDF_PARAM_SIZE)) != NULL) {
279	0	if (!OSSL_PARAM_set_size_t(p, SIZE_MAX))
280	0	return 0;
281	0	}
282	0	if (!OSSL_FIPS_IND_GET_CTX_PARAM(((KDF_SSHKDF *)vctx), params))
283	0	return 0;
284	0	return 1;
285	0	}
286
287		static const OSSL_PARAM kdf_sshkdf_gettable_ctx_params(ossl_unused void ctx,
288		ossl_unused void *p_ctx)
289	0	{
290	0	static const OSSL_PARAM known_gettable_ctx_params[] = {
291	0	OSSL_PARAM_size_t(OSSL_KDF_PARAM_SIZE, NULL),
292	0	OSSL_FIPS_IND_GETTABLE_CTX_PARAM()
293	0	OSSL_PARAM_END
294	0	};
295	0	return known_gettable_ctx_params;
296	0	}
297
298		const OSSL_DISPATCH ossl_kdf_sshkdf_functions[] = {
299		{ OSSL_FUNC_KDF_NEWCTX, (void(*)(void))kdf_sshkdf_new },
300		{ OSSL_FUNC_KDF_DUPCTX, (void(*)(void))kdf_sshkdf_dup },
301		{ OSSL_FUNC_KDF_FREECTX, (void(*)(void))kdf_sshkdf_free },
302		{ OSSL_FUNC_KDF_RESET, (void(*)(void))kdf_sshkdf_reset },
303		{ OSSL_FUNC_KDF_DERIVE, (void(*)(void))kdf_sshkdf_derive },
304		{ OSSL_FUNC_KDF_SETTABLE_CTX_PARAMS,
305		(void(*)(void))kdf_sshkdf_settable_ctx_params },
306		{ OSSL_FUNC_KDF_SET_CTX_PARAMS, (void(*)(void))kdf_sshkdf_set_ctx_params },
307		{ OSSL_FUNC_KDF_GETTABLE_CTX_PARAMS,
308		(void(*)(void))kdf_sshkdf_gettable_ctx_params },
309		{ OSSL_FUNC_KDF_GET_CTX_PARAMS, (void(*)(void))kdf_sshkdf_get_ctx_params },
310		OSSL_DISPATCH_END
311		};
312
313		static int SSHKDF(const EVP_MD *evp_md,
314		const unsigned char *key, size_t key_len,
315		const unsigned char *xcghash, size_t xcghash_len,
316		const unsigned char *session_id, size_t session_id_len,
317		char type, unsigned char *okey, size_t okey_len)
318	0	{
319	0	EVP_MD_CTX *md = NULL;
320	0	unsigned char digest[EVP_MAX_MD_SIZE];
321	0	unsigned int dsize = 0;
322	0	size_t cursize = 0;
323	0	int ret = 0;
324
325	0	md = EVP_MD_CTX_new();
326	0	if (md == NULL)
327	0	return 0;
328
329	0	if (!EVP_DigestInit_ex(md, evp_md, NULL))
330	0	goto out;
331
332	0	if (!EVP_DigestUpdate(md, key, key_len))
333	0	goto out;
334
335	0	if (!EVP_DigestUpdate(md, xcghash, xcghash_len))
336	0	goto out;
337
338	0	if (!EVP_DigestUpdate(md, &type, 1))
339	0	goto out;
340
341	0	if (!EVP_DigestUpdate(md, session_id, session_id_len))
342	0	goto out;
343
344	0	if (!EVP_DigestFinal_ex(md, digest, &dsize))
345	0	goto out;
346
347	0	if (okey_len < dsize) {
348	0	memcpy(okey, digest, okey_len);
349	0	ret = 1;
350	0	goto out;
351	0	}
352
353	0	memcpy(okey, digest, dsize);
354
355	0	for (cursize = dsize; cursize < okey_len; cursize += dsize) {
356
357	0	if (!EVP_DigestInit_ex(md, evp_md, NULL))
358	0	goto out;
359
360	0	if (!EVP_DigestUpdate(md, key, key_len))
361	0	goto out;
362
363	0	if (!EVP_DigestUpdate(md, xcghash, xcghash_len))
364	0	goto out;
365
366	0	if (!EVP_DigestUpdate(md, okey, cursize))
367	0	goto out;
368
369	0	if (!EVP_DigestFinal_ex(md, digest, &dsize))
370	0	goto out;
371
372	0	if (okey_len < cursize + dsize) {
373	0	memcpy(okey + cursize, digest, okey_len - cursize);
374	0	ret = 1;
375	0	goto out;
376	0	}
377
378	0	memcpy(okey + cursize, digest, dsize);
379	0	}
380
381	0	ret = 1;
382
383	0	out:
384	0	EVP_MD_CTX_free(md);
385	0	OPENSSL_cleanse(digest, EVP_MAX_MD_SIZE);
386	0	return ret;
387	0	}