/src/openssl/crypto/dh/dh_check.c

Source (jump to first uncovered line)
/*
 * Copyright 1995-2024 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
 */

/*
 * DH low level APIs are deprecated for public use, but still ok for
 * internal use.
 */
#include "internal/deprecated.h"

#include <stdio.h>
#include "internal/cryptlib.h"
#include <openssl/bn.h>
#include <openssl/self_test.h>
#include "dh_local.h"
#include "crypto/dh.h"

/*-
 * Check that p and g are suitable enough
 *
 * p is odd
 * 1 < g < p - 1
 */
int DH_check_params_ex(const DH *dh)
{
    int errflags = 0;

    if (!DH_check_params(dh, &errflags))
        return 0;

    if ((errflags & DH_CHECK_P_NOT_PRIME) != 0)
        ERR_raise(ERR_LIB_DH, DH_R_CHECK_P_NOT_PRIME);
    if ((errflags & DH_NOT_SUITABLE_GENERATOR) != 0)
        ERR_raise(ERR_LIB_DH, DH_R_NOT_SUITABLE_GENERATOR);
    if ((errflags & DH_MODULUS_TOO_SMALL) != 0)
        ERR_raise(ERR_LIB_DH, DH_R_MODULUS_TOO_SMALL);
    if ((errflags & DH_MODULUS_TOO_LARGE) != 0)
        ERR_raise(ERR_LIB_DH, DH_R_MODULUS_TOO_LARGE);

    return errflags == 0;
}

#ifdef FIPS_MODULE
int DH_check_params(const DH *dh, int *ret)
{
    int nid;

    *ret = 0;
    /*
     * SP800-56A R3 Section 5.5.2 Assurances of Domain Parameter Validity
     * (1a) The domain parameters correspond to any approved safe prime group.
     */
    nid = DH_get_nid((DH *)dh);
    if (nid != NID_undef)
        return 1;
    /*
     * OR
     * (2b) FFC domain params conform to FIPS-186-4 explicit domain param
     * validity tests.
     */
    return ossl_ffc_params_FIPS186_4_validate(dh->libctx, &dh->params,
                                              FFC_PARAM_TYPE_DH, ret, NULL);
}
#else
int DH_check_params(const DH *dh, int *ret)
{
    int ok = 0;
    BIGNUM *tmp = NULL;
    BN_CTX *ctx = NULL;

    *ret = 0;
    ctx = BN_CTX_new_ex(dh->libctx);
    if (ctx == NULL)
        goto err;
    BN_CTX_start(ctx);
    tmp = BN_CTX_get(ctx);
    if (tmp == NULL)
        goto err;

    if (!BN_is_odd(dh->params.p))
        *ret |= DH_CHECK_P_NOT_PRIME;
    if (BN_is_negative(dh->params.g)
        || BN_is_zero(dh->params.g)
        || BN_is_one(dh->params.g))
        *ret |= DH_NOT_SUITABLE_GENERATOR;
    if (BN_copy(tmp, dh->params.p) == NULL || !BN_sub_word(tmp, 1))
        goto err;
    if (BN_cmp(dh->params.g, tmp) >= 0)
        *ret |= DH_NOT_SUITABLE_GENERATOR;
    if (BN_num_bits(dh->params.p) < DH_MIN_MODULUS_BITS)
        *ret |= DH_MODULUS_TOO_SMALL;
    if (BN_num_bits(dh->params.p) > OPENSSL_DH_MAX_MODULUS_BITS)
        *ret |= DH_MODULUS_TOO_LARGE;

    ok = 1;
 err:
    BN_CTX_end(ctx);
    BN_CTX_free(ctx);
    return ok;
}
#endif /* FIPS_MODULE */

/*-
 * Check that p is a safe prime and
 * g is a suitable generator.
 */
int DH_check_ex(const DH *dh)
{
    int errflags = 0;

    if (!DH_check(dh, &errflags))
        return 0;

    if ((errflags & DH_NOT_SUITABLE_GENERATOR) != 0)
        ERR_raise(ERR_LIB_DH, DH_R_NOT_SUITABLE_GENERATOR);
    if ((errflags & DH_CHECK_Q_NOT_PRIME) != 0)
        ERR_raise(ERR_LIB_DH, DH_R_CHECK_Q_NOT_PRIME);
    if ((errflags & DH_CHECK_INVALID_Q_VALUE) != 0)
        ERR_raise(ERR_LIB_DH, DH_R_CHECK_INVALID_Q_VALUE);
    if ((errflags & DH_CHECK_INVALID_J_VALUE) != 0)
        ERR_raise(ERR_LIB_DH, DH_R_CHECK_INVALID_J_VALUE);
    if ((errflags & DH_UNABLE_TO_CHECK_GENERATOR) != 0)
        ERR_raise(ERR_LIB_DH, DH_R_UNABLE_TO_CHECK_GENERATOR);
    if ((errflags & DH_CHECK_P_NOT_PRIME) != 0)
        ERR_raise(ERR_LIB_DH, DH_R_CHECK_P_NOT_PRIME);
    if ((errflags & DH_CHECK_P_NOT_SAFE_PRIME) != 0)
        ERR_raise(ERR_LIB_DH, DH_R_CHECK_P_NOT_SAFE_PRIME);
    if ((errflags & DH_MODULUS_TOO_SMALL) != 0)
        ERR_raise(ERR_LIB_DH, DH_R_MODULUS_TOO_SMALL);
    if ((errflags & DH_MODULUS_TOO_LARGE) != 0)
        ERR_raise(ERR_LIB_DH, DH_R_MODULUS_TOO_LARGE);

    return errflags == 0;
}

/* Note: according to documentation - this only checks the params */
int DH_check(const DH *dh, int *ret)
{
#ifdef FIPS_MODULE
    return DH_check_params(dh, ret);
#else
    int ok = 0, r, q_good = 0;
    BN_CTX *ctx = NULL;
    BIGNUM *t1 = NULL, *t2 = NULL;
    int nid = DH_get_nid((DH *)dh);

    *ret = 0;
    if (nid != NID_undef)
        return 1;

    /* Don't do any checks at all with an excessively large modulus */
    if (BN_num_bits(dh->params.p) > OPENSSL_DH_CHECK_MAX_MODULUS_BITS) {
        ERR_raise(ERR_LIB_DH, DH_R_MODULUS_TOO_LARGE);
        *ret = DH_MODULUS_TOO_LARGE | DH_CHECK_P_NOT_PRIME;
        return 0;
    }

    if (!DH_check_params(dh, ret))
        return 0;

    ctx = BN_CTX_new_ex(dh->libctx);
    if (ctx == NULL)
        goto err;
    BN_CTX_start(ctx);
    t1 = BN_CTX_get(ctx);
    t2 = BN_CTX_get(ctx);
    if (t2 == NULL)
        goto err;

    if (dh->params.q != NULL) {
        if (BN_ucmp(dh->params.p, dh->params.q) > 0)
            q_good = 1;
        else
            *ret |= DH_CHECK_INVALID_Q_VALUE;
    }

    if (q_good) {
        if (BN_cmp(dh->params.g, BN_value_one()) <= 0)
            *ret |= DH_NOT_SUITABLE_GENERATOR;
        else if (BN_cmp(dh->params.g, dh->params.p) >= 0)
            *ret |= DH_NOT_SUITABLE_GENERATOR;
        else {
            /* Check g^q == 1 mod p */
            if (!BN_mod_exp(t1, dh->params.g, dh->params.q, dh->params.p, ctx))
                goto err;
            if (!BN_is_one(t1))
                *ret |= DH_NOT_SUITABLE_GENERATOR;
        }
        r = BN_check_prime(dh->params.q, ctx, NULL);
        if (r < 0)
            goto err;
        if (!r)
            *ret |= DH_CHECK_Q_NOT_PRIME;
        /* Check p == 1 mod q  i.e. q divides p - 1 */
        if (!BN_div(t1, t2, dh->params.p, dh->params.q, ctx))
            goto err;
        if (!BN_is_one(t2))
            *ret |= DH_CHECK_INVALID_Q_VALUE;
        if (dh->params.j != NULL
            && BN_cmp(dh->params.j, t1))
            *ret |= DH_CHECK_INVALID_J_VALUE;
    }

    r = BN_check_prime(dh->params.p, ctx, NULL);
    if (r < 0)
        goto err;
    if (!r)
        *ret |= DH_CHECK_P_NOT_PRIME;
    else if (dh->params.q == NULL) {
        if (!BN_rshift1(t1, dh->params.p))
            goto err;
        r = BN_check_prime(t1, ctx, NULL);
        if (r < 0)
            goto err;
        if (!r)
            *ret |= DH_CHECK_P_NOT_SAFE_PRIME;
    }
    ok = 1;
 err:
    BN_CTX_end(ctx);
    BN_CTX_free(ctx);
    return ok;
#endif /* FIPS_MODULE */
}

int DH_check_pub_key_ex(const DH *dh, const BIGNUM *pub_key)
{
    int errflags = 0;

    if (!DH_check_pub_key(dh, pub_key, &errflags))
        return 0;

    if ((errflags & DH_CHECK_PUBKEY_TOO_SMALL) != 0)
        ERR_raise(ERR_LIB_DH, DH_R_CHECK_PUBKEY_TOO_SMALL);
    if ((errflags & DH_CHECK_PUBKEY_TOO_LARGE) != 0)
        ERR_raise(ERR_LIB_DH, DH_R_CHECK_PUBKEY_TOO_LARGE);
    if ((errflags & DH_CHECK_PUBKEY_INVALID) != 0)
        ERR_raise(ERR_LIB_DH, DH_R_CHECK_PUBKEY_INVALID);

    return errflags == 0;
}

/*
 * See SP800-56Ar3 Section 5.6.2.3.1 : FFC Full public key validation.
 */
int DH_check_pub_key(const DH *dh, const BIGNUM *pub_key, int *ret)
{
    /* Don't do any checks at all with an excessively large modulus */
    if (BN_num_bits(dh->params.p) > OPENSSL_DH_CHECK_MAX_MODULUS_BITS) {
        ERR_raise(ERR_LIB_DH, DH_R_MODULUS_TOO_LARGE);
        *ret = DH_MODULUS_TOO_LARGE | DH_CHECK_PUBKEY_INVALID;
        return 0;
    }

    if (dh->params.q != NULL && BN_ucmp(dh->params.p, dh->params.q) < 0) {
        *ret |= DH_CHECK_INVALID_Q_VALUE | DH_CHECK_PUBKEY_INVALID;
        return 1;
    }

    return ossl_ffc_validate_public_key(&dh->params, pub_key, ret);
}

/*
 * See SP800-56Ar3 Section 5.6.2.3.1 : FFC Partial public key validation.
 * To only be used with ephemeral FFC public keys generated using the approved
 * safe-prime groups.
 */
int ossl_dh_check_pub_key_partial(const DH *dh, const BIGNUM *pub_key, int *ret)
{
    return ossl_ffc_validate_public_key_partial(&dh->params, pub_key, ret)
           && *ret == 0;
}

int ossl_dh_check_priv_key(const DH *dh, const BIGNUM *priv_key, int *ret)
{
    int ok = 0;
    BIGNUM *two_powN = NULL, *upper;

    *ret = 0;
    two_powN = BN_new();
    if (two_powN == NULL)
        return 0;

    if (dh->params.q != NULL) {
        upper = dh->params.q;
#ifndef FIPS_MODULE
    } else if (dh->params.p != NULL) {
        /*
         * We do not have q so we just check the key is within some
         * reasonable range, or the number of bits is equal to dh->length.
         */
        int length = dh->length;

        if (length == 0) {
            length = BN_num_bits(dh->params.p) - 1;
            if (BN_num_bits(priv_key) <= length
                && BN_num_bits(priv_key) > 1)
                ok = 1;
        } else if (BN_num_bits(priv_key) == length) {
            ok = 1;
        }
        goto end;
#endif
    } else {
        goto end;
    }

    /* Is it from an approved Safe prime group ?*/
    if (DH_get_nid((DH *)dh) != NID_undef && dh->length != 0) {
        if (!BN_lshift(two_powN, BN_value_one(), dh->length))
            goto end;
        if (BN_cmp(two_powN, dh->params.q) < 0)
            upper = two_powN;
    }
    if (!ossl_ffc_validate_private_key(upper, priv_key, ret))
        goto end;

    ok = 1;
end:
    BN_free(two_powN);
    return ok;
}

/*
 * FFC pairwise check from SP800-56A R3.
 *    Section 5.6.2.1.4 Owner Assurance of Pair-wise Consistency
 */
int ossl_dh_check_pairwise(const DH *dh, int return_on_null_numbers)
{
    int ret = 0;
    BN_CTX *ctx = NULL;
    BIGNUM *pub_key = NULL;
    OSSL_SELF_TEST *st = NULL;
    OSSL_CALLBACK *stcb = NULL;
    void *stcbarg = NULL;

    if (dh->params.p == NULL
        || dh->params.g == NULL
        || dh->priv_key == NULL
        || dh->pub_key == NULL)
        return return_on_null_numbers;

    OSSL_SELF_TEST_get_callback(dh->libctx, &stcb, &stcbarg);
    st = OSSL_SELF_TEST_new(stcb, stcbarg);
    if (st == NULL)
        goto err;
    OSSL_SELF_TEST_onbegin(st, OSSL_SELF_TEST_TYPE_PCT,
                           OSSL_SELF_TEST_DESC_PCT_DH);

    ctx = BN_CTX_new_ex(dh->libctx);
    if (ctx == NULL)
        goto err;
    pub_key = BN_new();
    if (pub_key == NULL)
        goto err;

    /* recalculate the public key = (g ^ priv) mod p */
    if (!ossl_dh_generate_public_key(ctx, dh, dh->priv_key, pub_key))
        goto err;

#ifdef FIPS_MODULE
    {
        int len;
        unsigned char bytes[1024] = {0};    /* Max key size of 8192 bits */

        if (BN_num_bytes(pub_key) > (int)sizeof(bytes))
            goto err;
        len = BN_bn2bin(pub_key, bytes);
        OSSL_SELF_TEST_oncorrupt_byte(st, bytes);
        if (BN_bin2bn(bytes, len, pub_key) == NULL)
            goto err;
    }
#endif
    /* check it matches the existing public_key */
    ret = BN_cmp(pub_key, dh->pub_key) == 0;
 err:
    BN_free(pub_key);
    BN_CTX_free(ctx);

    OSSL_SELF_TEST_onend(st, ret);
    OSSL_SELF_TEST_free(st);
    return ret;
}

Coverage Report

Created: 2025-08-25 06:30

Line	Count	Source (jump to first uncovered line)
1		/*
2		* Copyright 1995-2024 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		/*
11		* DH low level APIs are deprecated for public use, but still ok for
12		* internal use.
13		*/
14		#include "internal/deprecated.h"
15
16		#include <stdio.h>
17		#include "internal/cryptlib.h"
18		#include <openssl/bn.h>
19		#include <openssl/self_test.h>
20		#include "dh_local.h"
21		#include "crypto/dh.h"
22
23		/*-
24		* Check that p and g are suitable enough
25		*
26		* p is odd
27		* 1 < g < p - 1
28		*/
29		int DH_check_params_ex(const DH *dh)
30	0	{
31	0	int errflags = 0;
32
33	0	if (!DH_check_params(dh, &errflags))
34	0	return 0;
35
36	0	if ((errflags & DH_CHECK_P_NOT_PRIME) != 0)
37	0	ERR_raise(ERR_LIB_DH, DH_R_CHECK_P_NOT_PRIME);
38	0	if ((errflags & DH_NOT_SUITABLE_GENERATOR) != 0)
39	0	ERR_raise(ERR_LIB_DH, DH_R_NOT_SUITABLE_GENERATOR);
40	0	if ((errflags & DH_MODULUS_TOO_SMALL) != 0)
41	0	ERR_raise(ERR_LIB_DH, DH_R_MODULUS_TOO_SMALL);
42	0	if ((errflags & DH_MODULUS_TOO_LARGE) != 0)
43	0	ERR_raise(ERR_LIB_DH, DH_R_MODULUS_TOO_LARGE);
44
45	0	return errflags == 0;
46	0	}
47
48		#ifdef FIPS_MODULE
49		int DH_check_params(const DH dh, int ret)
50		{
51		int nid;
52
53		*ret = 0;
54		/*
55		* SP800-56A R3 Section 5.5.2 Assurances of Domain Parameter Validity
56		* (1a) The domain parameters correspond to any approved safe prime group.
57		*/
58		nid = DH_get_nid((DH *)dh);
59		if (nid != NID_undef)
60		return 1;
61		/*
62		* OR
63		* (2b) FFC domain params conform to FIPS-186-4 explicit domain param
64		* validity tests.
65		*/
66		return ossl_ffc_params_FIPS186_4_validate(dh->libctx, &dh->params,
67		FFC_PARAM_TYPE_DH, ret, NULL);
68		}
69		#else
70		int DH_check_params(const DH dh, int ret)
71	0	{
72	0	int ok = 0;
73	0	BIGNUM *tmp = NULL;
74	0	BN_CTX *ctx = NULL;
75
76	0	*ret = 0;
77	0	ctx = BN_CTX_new_ex(dh->libctx);
78	0	if (ctx == NULL)
79	0	goto err;
80	0	BN_CTX_start(ctx);
81	0	tmp = BN_CTX_get(ctx);
82	0	if (tmp == NULL)
83	0	goto err;
84
85	0	if (!BN_is_odd(dh->params.p))
86	0	*ret \|= DH_CHECK_P_NOT_PRIME;
87	0	if (BN_is_negative(dh->params.g)
88	0	\|\| BN_is_zero(dh->params.g)
89	0	\|\| BN_is_one(dh->params.g))
90	0	*ret \|= DH_NOT_SUITABLE_GENERATOR;
91	0	if (BN_copy(tmp, dh->params.p) == NULL \|\| !BN_sub_word(tmp, 1))
92	0	goto err;
93	0	if (BN_cmp(dh->params.g, tmp) >= 0)
94	0	*ret \|= DH_NOT_SUITABLE_GENERATOR;
95	0	if (BN_num_bits(dh->params.p) < DH_MIN_MODULUS_BITS)
96	0	*ret \|= DH_MODULUS_TOO_SMALL;
97	0	if (BN_num_bits(dh->params.p) > OPENSSL_DH_MAX_MODULUS_BITS)
98	0	*ret \|= DH_MODULUS_TOO_LARGE;
99
100	0	ok = 1;
101	0	err:
102	0	BN_CTX_end(ctx);
103	0	BN_CTX_free(ctx);
104	0	return ok;
105	0	}
106		#endif /* FIPS_MODULE */
107
108		/*-
109		* Check that p is a safe prime and
110		* g is a suitable generator.
111		*/
112		int DH_check_ex(const DH *dh)
113	0	{
114	0	int errflags = 0;
115
116	0	if (!DH_check(dh, &errflags))
117	0	return 0;
118
119	0	if ((errflags & DH_NOT_SUITABLE_GENERATOR) != 0)
120	0	ERR_raise(ERR_LIB_DH, DH_R_NOT_SUITABLE_GENERATOR);
121	0	if ((errflags & DH_CHECK_Q_NOT_PRIME) != 0)
122	0	ERR_raise(ERR_LIB_DH, DH_R_CHECK_Q_NOT_PRIME);
123	0	if ((errflags & DH_CHECK_INVALID_Q_VALUE) != 0)
124	0	ERR_raise(ERR_LIB_DH, DH_R_CHECK_INVALID_Q_VALUE);
125	0	if ((errflags & DH_CHECK_INVALID_J_VALUE) != 0)
126	0	ERR_raise(ERR_LIB_DH, DH_R_CHECK_INVALID_J_VALUE);
127	0	if ((errflags & DH_UNABLE_TO_CHECK_GENERATOR) != 0)
128	0	ERR_raise(ERR_LIB_DH, DH_R_UNABLE_TO_CHECK_GENERATOR);
129	0	if ((errflags & DH_CHECK_P_NOT_PRIME) != 0)
130	0	ERR_raise(ERR_LIB_DH, DH_R_CHECK_P_NOT_PRIME);
131	0	if ((errflags & DH_CHECK_P_NOT_SAFE_PRIME) != 0)
132	0	ERR_raise(ERR_LIB_DH, DH_R_CHECK_P_NOT_SAFE_PRIME);
133	0	if ((errflags & DH_MODULUS_TOO_SMALL) != 0)
134	0	ERR_raise(ERR_LIB_DH, DH_R_MODULUS_TOO_SMALL);
135	0	if ((errflags & DH_MODULUS_TOO_LARGE) != 0)
136	0	ERR_raise(ERR_LIB_DH, DH_R_MODULUS_TOO_LARGE);
137
138	0	return errflags == 0;
139	0	}
140
141		/* Note: according to documentation - this only checks the params */
142		int DH_check(const DH dh, int ret)
143	0	{
144		#ifdef FIPS_MODULE
145		return DH_check_params(dh, ret);
146		#else
147	0	int ok = 0, r, q_good = 0;
148	0	BN_CTX *ctx = NULL;
149	0	BIGNUM t1 = NULL, t2 = NULL;
150	0	int nid = DH_get_nid((DH *)dh);
151
152	0	*ret = 0;
153	0	if (nid != NID_undef)
154	0	return 1;
155
156		/* Don't do any checks at all with an excessively large modulus */
157	0	if (BN_num_bits(dh->params.p) > OPENSSL_DH_CHECK_MAX_MODULUS_BITS) {
158	0	ERR_raise(ERR_LIB_DH, DH_R_MODULUS_TOO_LARGE);
159	0	*ret = DH_MODULUS_TOO_LARGE \| DH_CHECK_P_NOT_PRIME;
160	0	return 0;
161	0	}
162
163	0	if (!DH_check_params(dh, ret))
164	0	return 0;
165
166	0	ctx = BN_CTX_new_ex(dh->libctx);
167	0	if (ctx == NULL)
168	0	goto err;
169	0	BN_CTX_start(ctx);
170	0	t1 = BN_CTX_get(ctx);
171	0	t2 = BN_CTX_get(ctx);
172	0	if (t2 == NULL)
173	0	goto err;
174
175	0	if (dh->params.q != NULL) {
176	0	if (BN_ucmp(dh->params.p, dh->params.q) > 0)
177	0	q_good = 1;
178	0	else
179	0	*ret \|= DH_CHECK_INVALID_Q_VALUE;
180	0	}
181
182	0	if (q_good) {
183	0	if (BN_cmp(dh->params.g, BN_value_one()) <= 0)
184	0	*ret \|= DH_NOT_SUITABLE_GENERATOR;
185	0	else if (BN_cmp(dh->params.g, dh->params.p) >= 0)
186	0	*ret \|= DH_NOT_SUITABLE_GENERATOR;
187	0	else {
188		/* Check g^q == 1 mod p */
189	0	if (!BN_mod_exp(t1, dh->params.g, dh->params.q, dh->params.p, ctx))
190	0	goto err;
191	0	if (!BN_is_one(t1))
192	0	*ret \|= DH_NOT_SUITABLE_GENERATOR;
193	0	}
194	0	r = BN_check_prime(dh->params.q, ctx, NULL);
195	0	if (r < 0)
196	0	goto err;
197	0	if (!r)
198	0	*ret \|= DH_CHECK_Q_NOT_PRIME;
199		/* Check p == 1 mod q i.e. q divides p - 1 */
200	0	if (!BN_div(t1, t2, dh->params.p, dh->params.q, ctx))
201	0	goto err;
202	0	if (!BN_is_one(t2))
203	0	*ret \|= DH_CHECK_INVALID_Q_VALUE;
204	0	if (dh->params.j != NULL
205	0	&& BN_cmp(dh->params.j, t1))
206	0	*ret \|= DH_CHECK_INVALID_J_VALUE;
207	0	}
208
209	0	r = BN_check_prime(dh->params.p, ctx, NULL);
210	0	if (r < 0)
211	0	goto err;
212	0	if (!r)
213	0	*ret \|= DH_CHECK_P_NOT_PRIME;
214	0	else if (dh->params.q == NULL) {
215	0	if (!BN_rshift1(t1, dh->params.p))
216	0	goto err;
217	0	r = BN_check_prime(t1, ctx, NULL);
218	0	if (r < 0)
219	0	goto err;
220	0	if (!r)
221	0	*ret \|= DH_CHECK_P_NOT_SAFE_PRIME;
222	0	}
223	0	ok = 1;
224	0	err:
225	0	BN_CTX_end(ctx);
226	0	BN_CTX_free(ctx);
227	0	return ok;
228	0	#endif /* FIPS_MODULE */
229	0	}
230
231		int DH_check_pub_key_ex(const DH dh, const BIGNUM pub_key)
232	0	{
233	0	int errflags = 0;
234
235	0	if (!DH_check_pub_key(dh, pub_key, &errflags))
236	0	return 0;
237
238	0	if ((errflags & DH_CHECK_PUBKEY_TOO_SMALL) != 0)
239	0	ERR_raise(ERR_LIB_DH, DH_R_CHECK_PUBKEY_TOO_SMALL);
240	0	if ((errflags & DH_CHECK_PUBKEY_TOO_LARGE) != 0)
241	0	ERR_raise(ERR_LIB_DH, DH_R_CHECK_PUBKEY_TOO_LARGE);
242	0	if ((errflags & DH_CHECK_PUBKEY_INVALID) != 0)
243	0	ERR_raise(ERR_LIB_DH, DH_R_CHECK_PUBKEY_INVALID);
244
245	0	return errflags == 0;
246	0	}
247
248		/*
249		* See SP800-56Ar3 Section 5.6.2.3.1 : FFC Full public key validation.
250		*/
251		int DH_check_pub_key(const DH dh, const BIGNUM pub_key, int *ret)
252	0	{
253		/* Don't do any checks at all with an excessively large modulus */
254	0	if (BN_num_bits(dh->params.p) > OPENSSL_DH_CHECK_MAX_MODULUS_BITS) {
255	0	ERR_raise(ERR_LIB_DH, DH_R_MODULUS_TOO_LARGE);
256	0	*ret = DH_MODULUS_TOO_LARGE \| DH_CHECK_PUBKEY_INVALID;
257	0	return 0;
258	0	}
259
260	0	if (dh->params.q != NULL && BN_ucmp(dh->params.p, dh->params.q) < 0) {
261	0	*ret \|= DH_CHECK_INVALID_Q_VALUE \| DH_CHECK_PUBKEY_INVALID;
262	0	return 1;
263	0	}
264
265	0	return ossl_ffc_validate_public_key(&dh->params, pub_key, ret);
266	0	}
267
268		/*
269		* See SP800-56Ar3 Section 5.6.2.3.1 : FFC Partial public key validation.
270		* To only be used with ephemeral FFC public keys generated using the approved
271		* safe-prime groups.
272		*/
273		int ossl_dh_check_pub_key_partial(const DH dh, const BIGNUM pub_key, int *ret)
274	0	{
275	0	return ossl_ffc_validate_public_key_partial(&dh->params, pub_key, ret)
276	0	&& *ret == 0;
277	0	}
278
279		int ossl_dh_check_priv_key(const DH dh, const BIGNUM priv_key, int *ret)
280	0	{
281	0	int ok = 0;
282	0	BIGNUM two_powN = NULL, upper;
283
284	0	*ret = 0;
285	0	two_powN = BN_new();
286	0	if (two_powN == NULL)
287	0	return 0;
288
289	0	if (dh->params.q != NULL) {
290	0	upper = dh->params.q;
291	0	#ifndef FIPS_MODULE
292	0	} else if (dh->params.p != NULL) {
293		/*
294		* We do not have q so we just check the key is within some
295		* reasonable range, or the number of bits is equal to dh->length.
296		*/
297	0	int length = dh->length;
298
299	0	if (length == 0) {
300	0	length = BN_num_bits(dh->params.p) - 1;
301	0	if (BN_num_bits(priv_key) <= length
302	0	&& BN_num_bits(priv_key) > 1)
303	0	ok = 1;
304	0	} else if (BN_num_bits(priv_key) == length) {
305	0	ok = 1;
306	0	}
307	0	goto end;
308	0	#endif
309	0	} else {
310	0	goto end;
311	0	}
312
313		/* Is it from an approved Safe prime group ?*/
314	0	if (DH_get_nid((DH *)dh) != NID_undef && dh->length != 0) {
315	0	if (!BN_lshift(two_powN, BN_value_one(), dh->length))
316	0	goto end;
317	0	if (BN_cmp(two_powN, dh->params.q) < 0)
318	0	upper = two_powN;
319	0	}
320	0	if (!ossl_ffc_validate_private_key(upper, priv_key, ret))
321	0	goto end;
322
323	0	ok = 1;
324	0	end:
325	0	BN_free(two_powN);
326	0	return ok;
327	0	}
328
329		/*
330		* FFC pairwise check from SP800-56A R3.
331		* Section 5.6.2.1.4 Owner Assurance of Pair-wise Consistency
332		*/
333		int ossl_dh_check_pairwise(const DH *dh, int return_on_null_numbers)
334	0	{
335	0	int ret = 0;
336	0	BN_CTX *ctx = NULL;
337	0	BIGNUM *pub_key = NULL;
338	0	OSSL_SELF_TEST *st = NULL;
339	0	OSSL_CALLBACK *stcb = NULL;
340	0	void *stcbarg = NULL;
341
342	0	if (dh->params.p == NULL
343	0	\|\| dh->params.g == NULL
344	0	\|\| dh->priv_key == NULL
345	0	\|\| dh->pub_key == NULL)
346	0	return return_on_null_numbers;
347
348	0	OSSL_SELF_TEST_get_callback(dh->libctx, &stcb, &stcbarg);
349	0	st = OSSL_SELF_TEST_new(stcb, stcbarg);
350	0	if (st == NULL)
351	0	goto err;
352	0	OSSL_SELF_TEST_onbegin(st, OSSL_SELF_TEST_TYPE_PCT,
353	0	OSSL_SELF_TEST_DESC_PCT_DH);
354
355	0	ctx = BN_CTX_new_ex(dh->libctx);
356	0	if (ctx == NULL)
357	0	goto err;
358	0	pub_key = BN_new();
359	0	if (pub_key == NULL)
360	0	goto err;
361
362		/* recalculate the public key = (g ^ priv) mod p */
363	0	if (!ossl_dh_generate_public_key(ctx, dh, dh->priv_key, pub_key))
364	0	goto err;
365
366		#ifdef FIPS_MODULE
367		{
368		int len;
369		unsigned char bytes[1024] = {0}; /* Max key size of 8192 bits */
370
371		if (BN_num_bytes(pub_key) > (int)sizeof(bytes))
372		goto err;
373		len = BN_bn2bin(pub_key, bytes);
374		OSSL_SELF_TEST_oncorrupt_byte(st, bytes);
375		if (BN_bin2bn(bytes, len, pub_key) == NULL)
376		goto err;
377		}
378		#endif
379		/* check it matches the existing public_key */
380	0	ret = BN_cmp(pub_key, dh->pub_key) == 0;
381	0	err:
382	0	BN_free(pub_key);
383	0	BN_CTX_free(ctx);
384
385	0	OSSL_SELF_TEST_onend(st, ret);
386	0	OSSL_SELF_TEST_free(st);
387	0	return ret;
388	0	}