[thirdparty/openssl.git] / crypto / dh / dh_check.c

/*
 * Copyright 1995-2019 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 "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)
        DHerr(DH_F_DH_CHECK_PARAMS_EX, DH_R_CHECK_P_NOT_PRIME);
    if ((errflags & DH_NOT_SUITABLE_GENERATOR) != 0)
        DHerr(DH_F_DH_CHECK_PARAMS_EX, DH_R_NOT_SUITABLE_GENERATOR);
    if ((errflags & DH_MODULUS_TOO_SMALL) != 0)
        DHerr(DH_F_DH_CHECK_PARAMS_EX, DH_R_MODULUS_TOO_SMALL);
    if ((errflags & DH_MODULUS_TOO_LARGE) != 0)
        DHerr(DH_F_DH_CHECK_PARAMS_EX, DH_R_MODULUS_TOO_LARGE);

    return errflags == 0;
}

#ifdef FIPS_MODE
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 ffc_params_FIPS186_4_validate(&dh->params, FFC_PARAM_TYPE_DH, NULL,
                                         FFC_PARAMS_VALIDATE_ALL, 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();
    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_MODE */

/*-
 * 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)
        DHerr(DH_F_DH_CHECK_EX, DH_R_NOT_SUITABLE_GENERATOR);
    if ((errflags & DH_CHECK_Q_NOT_PRIME) != 0)
        DHerr(DH_F_DH_CHECK_EX, DH_R_CHECK_Q_NOT_PRIME);
    if ((errflags & DH_CHECK_INVALID_Q_VALUE) != 0)
        DHerr(DH_F_DH_CHECK_EX, DH_R_CHECK_INVALID_Q_VALUE);
    if ((errflags & DH_CHECK_INVALID_J_VALUE) != 0)
        DHerr(DH_F_DH_CHECK_EX, DH_R_CHECK_INVALID_J_VALUE);
    if ((errflags & DH_UNABLE_TO_CHECK_GENERATOR) != 0)
        DHerr(DH_F_DH_CHECK_EX, DH_R_UNABLE_TO_CHECK_GENERATOR);
    if ((errflags & DH_CHECK_P_NOT_PRIME) != 0)
        DHerr(DH_F_DH_CHECK_EX, DH_R_CHECK_P_NOT_PRIME);
    if ((errflags & DH_CHECK_P_NOT_SAFE_PRIME) != 0)
        DHerr(DH_F_DH_CHECK_EX, DH_R_CHECK_P_NOT_SAFE_PRIME);
    if ((errflags & DH_MODULUS_TOO_SMALL) != 0)
        DHerr(DH_F_DH_CHECK_EX, DH_R_MODULUS_TOO_SMALL);
    if ((errflags & DH_MODULUS_TOO_LARGE) != 0)
        DHerr(DH_F_DH_CHECK_EX, 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_MODE
    return DH_check_params(dh, ret);
#else
    int ok = 0, r;
    BN_CTX *ctx = NULL;
    BIGNUM *t1 = NULL, *t2 = NULL;
    int nid = DH_get_nid((DH *)dh);

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

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

    ctx = BN_CTX_new();
    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_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_MODE */
}

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)
        DHerr(DH_F_DH_CHECK_PUB_KEY_EX, DH_R_CHECK_PUBKEY_TOO_SMALL);
    if ((errflags & DH_CHECK_PUBKEY_TOO_LARGE) != 0)
        DHerr(DH_F_DH_CHECK_PUB_KEY_EX, DH_R_CHECK_PUBKEY_TOO_LARGE);
    if ((errflags & DH_CHECK_PUBKEY_INVALID) != 0)
        DHerr(DH_F_DH_CHECK_PUB_KEY_EX, 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)
{
    return 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 dh_check_pub_key_partial(const DH *dh, const BIGNUM *pub_key, int *ret)
{
    return ffc_validate_public_key_partial(&dh->params, pub_key, ret);
}

int 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)
        goto err;
    upper = dh->params.q;

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

    ok = 1;
err:
    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 dh_check_pairwise(DH *dh)
{
    int ret = 0;
    BN_CTX *ctx = NULL;
    BIGNUM *pub_key = NULL;

    if (dh->params.p == NULL
        || dh->params.g == NULL
        || dh->priv_key == NULL
        || dh->pub_key == NULL)
        return 0;

    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 (!dh_generate_public_key(ctx, dh, dh->priv_key, pub_key))
        goto err;
    /* check it matches the existing pubic_key */
    ret = BN_cmp(pub_key, dh->pub_key) == 0;
err:
    BN_free(pub_key);
    BN_CTX_free(ctx);
    return ret;
}
Commit	Line	Data
aa6bb135	1	/*
a38c878c	2	* Copyright 1995-2019 The OpenSSL Project Authors. All Rights Reserved.
d02b48c6	3	*
e38873f5	4	* Licensed under the Apache License 2.0 (the "License"). You may not use
aa6bb135 RS	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
d02b48c6 RE	8	*/
d02b48c6 RE	9
ada66e78 P	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
d02b48c6	16	#include <stdio.h>
b39fc560	17	#include "internal/cryptlib.h"
ec577822	18	#include <openssl/bn.h>
706457b7	19	#include "dh_local.h"
8083fd3a	20	#include "crypto/dh.h"
d02b48c6	21
26505153 RL	22	/*-
	23	* Check that p and g are suitable enough
	24	*
	25	* p is odd
	26	* 1 < g < p - 1
	27	*/
b0004708 PY	28	int DH_check_params_ex(const DH *dh)
	29	{
	30	int errflags = 0;
	31
a38c878c BE	32	if (!DH_check_params(dh, &errflags))
a38c878c BE	33	return 0;
b0004708 PY	34
	35	if ((errflags & DH_CHECK_P_NOT_PRIME) != 0)
	36	DHerr(DH_F_DH_CHECK_PARAMS_EX, DH_R_CHECK_P_NOT_PRIME);
	37	if ((errflags & DH_NOT_SUITABLE_GENERATOR) != 0)
	38	DHerr(DH_F_DH_CHECK_PARAMS_EX, DH_R_NOT_SUITABLE_GENERATOR);
feeb7ecd BE	39	if ((errflags & DH_MODULUS_TOO_SMALL) != 0)
	40	DHerr(DH_F_DH_CHECK_PARAMS_EX, DH_R_MODULUS_TOO_SMALL);
	41	if ((errflags & DH_MODULUS_TOO_LARGE) != 0)
	42	DHerr(DH_F_DH_CHECK_PARAMS_EX, DH_R_MODULUS_TOO_LARGE);
b0004708 PY	43
	44	return errflags == 0;
	45	}
26505153	46
8083fd3a SL	47	#ifdef FIPS_MODE
	48	int DH_check_params(const DH dh, int ret)
	49	{
	50	int nid;
	51
	52	*ret = 0;
	53	/*
	54	* SP800-56A R3 Section 5.5.2 Assurances of Domain Parameter Validity
	55	* (1a) The domain parameters correspond to any approved safe prime group.
	56	*/
	57	nid = DH_get_nid((DH *)dh);
	58	if (nid != NID_undef)
	59	return 1;
	60	/*
	61	* OR
	62	* (2b) FFC domain params conform to FIPS-186-4 explicit domain param
	63	* validity tests.
	64	*/
	65	return ffc_params_FIPS186_4_validate(&dh->params, FFC_PARAM_TYPE_DH, NULL,
	66	FFC_PARAMS_VALIDATE_ALL, ret, NULL);
	67	}
	68	#else
26505153 RL	69	int DH_check_params(const DH dh, int ret)
	70	{
	71	int ok = 0;
	72	BIGNUM *tmp = NULL;
	73	BN_CTX *ctx = NULL;
	74
	75	*ret = 0;
	76	ctx = BN_CTX_new();
	77	if (ctx == NULL)
	78	goto err;
	79	BN_CTX_start(ctx);
	80	tmp = BN_CTX_get(ctx);
	81	if (tmp == NULL)
	82	goto err;
	83
dc8de3e6	84	if (!BN_is_odd(dh->params.p))
26505153	85	*ret \|= DH_CHECK_P_NOT_PRIME;
dc8de3e6 SL	86	if (BN_is_negative(dh->params.g)
	87	\|\| BN_is_zero(dh->params.g)
	88	\|\| BN_is_one(dh->params.g))
26505153	89	*ret \|= DH_NOT_SUITABLE_GENERATOR;
dc8de3e6	90	if (BN_copy(tmp, dh->params.p) == NULL \|\| !BN_sub_word(tmp, 1))
26505153	91	goto err;
dc8de3e6	92	if (BN_cmp(dh->params.g, tmp) >= 0)
26505153	93	*ret \|= DH_NOT_SUITABLE_GENERATOR;
dc8de3e6	94	if (BN_num_bits(dh->params.p) < DH_MIN_MODULUS_BITS)
feeb7ecd	95	*ret \|= DH_MODULUS_TOO_SMALL;
dc8de3e6	96	if (BN_num_bits(dh->params.p) > OPENSSL_DH_MAX_MODULUS_BITS)
feeb7ecd	97	*ret \|= DH_MODULUS_TOO_LARGE;
26505153 RL	98
	99	ok = 1;
	100	err:
ce1415ed SL	101	BN_CTX_end(ctx);
ce1415ed SL	102	BN_CTX_free(ctx);
26a7d938	103	return ok;
26505153	104	}
8083fd3a	105	#endif /* FIPS_MODE */
26505153	106
1d97c843 TH	107	/*-
1d97c843 TH	108	* Check that p is a safe prime and
a38c878c	109	* g is a suitable generator.
d02b48c6	110	*/
b0004708 PY	111	int DH_check_ex(const DH *dh)
	112	{
	113	int errflags = 0;
	114
a38c878c BE	115	if (!DH_check(dh, &errflags))
a38c878c BE	116	return 0;
b0004708 PY	117
	118	if ((errflags & DH_NOT_SUITABLE_GENERATOR) != 0)
	119	DHerr(DH_F_DH_CHECK_EX, DH_R_NOT_SUITABLE_GENERATOR);
	120	if ((errflags & DH_CHECK_Q_NOT_PRIME) != 0)
	121	DHerr(DH_F_DH_CHECK_EX, DH_R_CHECK_Q_NOT_PRIME);
	122	if ((errflags & DH_CHECK_INVALID_Q_VALUE) != 0)
	123	DHerr(DH_F_DH_CHECK_EX, DH_R_CHECK_INVALID_Q_VALUE);
	124	if ((errflags & DH_CHECK_INVALID_J_VALUE) != 0)
	125	DHerr(DH_F_DH_CHECK_EX, DH_R_CHECK_INVALID_J_VALUE);
	126	if ((errflags & DH_UNABLE_TO_CHECK_GENERATOR) != 0)
	127	DHerr(DH_F_DH_CHECK_EX, DH_R_UNABLE_TO_CHECK_GENERATOR);
	128	if ((errflags & DH_CHECK_P_NOT_PRIME) != 0)
	129	DHerr(DH_F_DH_CHECK_EX, DH_R_CHECK_P_NOT_PRIME);
	130	if ((errflags & DH_CHECK_P_NOT_SAFE_PRIME) != 0)
	131	DHerr(DH_F_DH_CHECK_EX, DH_R_CHECK_P_NOT_SAFE_PRIME);
feeb7ecd BE	132	if ((errflags & DH_MODULUS_TOO_SMALL) != 0)
	133	DHerr(DH_F_DH_CHECK_EX, DH_R_MODULUS_TOO_SMALL);
	134	if ((errflags & DH_MODULUS_TOO_LARGE) != 0)
	135	DHerr(DH_F_DH_CHECK_EX, DH_R_MODULUS_TOO_LARGE);
b0004708 PY	136
	137	return errflags == 0;
	138	}
d02b48c6	139
8083fd3a	140	/* Note: according to documentation - this only checks the params */
f971ccb2	141	int DH_check(const DH dh, int ret)
0f113f3e	142	{
8083fd3a SL	143	#ifdef FIPS_MODE
	144	return DH_check_params(dh, ret);
	145	#else
748e8530	146	int ok = 0, r;
0f113f3e	147	BN_CTX *ctx = NULL;
0f113f3e	148	BIGNUM t1 = NULL, t2 = NULL;
8083fd3a SL	149	int nid = DH_get_nid((DH *)dh);
	150
	151	*ret = 0;
	152	if (nid != NID_undef)
	153	return 1;
0f113f3e	154
a38c878c BE	155	if (!DH_check_params(dh, ret))
	156	return 0;
	157
0f113f3e MC	158	ctx = BN_CTX_new();
	159	if (ctx == NULL)
	160	goto err;
	161	BN_CTX_start(ctx);
	162	t1 = BN_CTX_get(ctx);
0f113f3e MC	163	t2 = BN_CTX_get(ctx);
	164	if (t2 == NULL)
	165	goto err;
d02b48c6	166
dc8de3e6 SL	167	if (dh->params.q != NULL) {
dc8de3e6 SL	168	if (BN_cmp(dh->params.g, BN_value_one()) <= 0)
0f113f3e	169	*ret \|= DH_NOT_SUITABLE_GENERATOR;
dc8de3e6	170	else if (BN_cmp(dh->params.g, dh->params.p) >= 0)
0f113f3e MC	171	*ret \|= DH_NOT_SUITABLE_GENERATOR;
	172	else {
	173	/* Check g^q == 1 mod p */
dc8de3e6	174	if (!BN_mod_exp(t1, dh->params.g, dh->params.q, dh->params.p, ctx))
0f113f3e MC	175	goto err;
	176	if (!BN_is_one(t1))
	177	*ret \|= DH_NOT_SUITABLE_GENERATOR;
	178	}
dc8de3e6	179	r = BN_check_prime(dh->params.q, ctx, NULL);
748e8530 DB	180	if (r < 0)
	181	goto err;
	182	if (!r)
0f113f3e MC	183	*ret \|= DH_CHECK_Q_NOT_PRIME;
0f113f3e MC	184	/* Check p == 1 mod q i.e. q divides p - 1 */
dc8de3e6	185	if (!BN_div(t1, t2, dh->params.p, dh->params.q, ctx))
0f113f3e MC	186	goto err;
	187	if (!BN_is_one(t2))
	188	*ret \|= DH_CHECK_INVALID_Q_VALUE;
dc8de3e6 SL	189	if (dh->params.j != NULL
dc8de3e6 SL	190	&& BN_cmp(dh->params.j, t1))
0f113f3e	191	*ret \|= DH_CHECK_INVALID_J_VALUE;
a38c878c	192	}
d02b48c6	193
dc8de3e6	194	r = BN_check_prime(dh->params.p, ctx, NULL);
748e8530 DB	195	if (r < 0)
	196	goto err;
	197	if (!r)
0f113f3e	198	*ret \|= DH_CHECK_P_NOT_PRIME;
dc8de3e6 SL	199	else if (dh->params.q == NULL) {
dc8de3e6 SL	200	if (!BN_rshift1(t1, dh->params.p))
0f113f3e	201	goto err;
42619397	202	r = BN_check_prime(t1, ctx, NULL);
748e8530 DB	203	if (r < 0)
748e8530 DB	204	goto err;
e705fcf1	205	if (!r)
0f113f3e MC	206	*ret \|= DH_CHECK_P_NOT_SAFE_PRIME;
	207	}
	208	ok = 1;
	209	err:
ce1415ed SL	210	BN_CTX_end(ctx);
ce1415ed SL	211	BN_CTX_free(ctx);
26a7d938	212	return ok;
8083fd3a	213	#endif /* FIPS_MODE */
0f113f3e	214	}
bf3d6c0c	215
b0004708 PY	216	int DH_check_pub_key_ex(const DH dh, const BIGNUM pub_key)
	217	{
	218	int errflags = 0;
	219
2b95e8ef BE	220	if (!DH_check_pub_key(dh, pub_key, &errflags))
2b95e8ef BE	221	return 0;
b0004708 PY	222
	223	if ((errflags & DH_CHECK_PUBKEY_TOO_SMALL) != 0)
	224	DHerr(DH_F_DH_CHECK_PUB_KEY_EX, DH_R_CHECK_PUBKEY_TOO_SMALL);
	225	if ((errflags & DH_CHECK_PUBKEY_TOO_LARGE) != 0)
	226	DHerr(DH_F_DH_CHECK_PUB_KEY_EX, DH_R_CHECK_PUBKEY_TOO_LARGE);
	227	if ((errflags & DH_CHECK_PUBKEY_INVALID) != 0)
	228	DHerr(DH_F_DH_CHECK_PUB_KEY_EX, DH_R_CHECK_PUBKEY_INVALID);
	229
	230	return errflags == 0;
	231	}
	232
8083fd3a SL	233	/*
	234	* See SP800-56Ar3 Section 5.6.2.3.1 : FFC Full public key validation.
	235	*/
bf3d6c0c	236	int DH_check_pub_key(const DH dh, const BIGNUM pub_key, int *ret)
8083fd3a SL	237	{
	238	return ffc_validate_public_key(&dh->params, pub_key, ret);
	239	}
	240
	241	/*
	242	* See SP800-56Ar3 Section 5.6.2.3.1 : FFC Partial public key validation.
	243	* To only be used with ephemeral FFC public keys generated using the approved
	244	* safe-prime groups.
	245	*/
	246	int dh_check_pub_key_partial(const DH dh, const BIGNUM pub_key, int *ret)
	247	{
	248	return ffc_validate_public_key_partial(&dh->params, pub_key, ret);
	249	}
	250
	251	int dh_check_priv_key(const DH dh, const BIGNUM priv_key, int *ret)
0f113f3e MC	252	{
0f113f3e MC	253	int ok = 0;
8083fd3a	254	BIGNUM two_powN = NULL, upper;
bf3d6c0c	255
0f113f3e	256	*ret = 0;
8083fd3a SL	257	two_powN = BN_new();
	258	if (two_powN == NULL)
	259	return 0;
	260	if (dh->params.q == NULL)
f5a12207	261	goto err;
8083fd3a	262	upper = dh->params.q;
bf3d6c0c	263
8083fd3a SL	264	/* Is it from an approved Safe prime group ?*/
	265	if (DH_get_nid((DH *)dh) != NID_undef) {
	266	if (!BN_lshift(two_powN, BN_value_one(), dh->length))
b128abc3	267	goto err;
8083fd3a SL	268	if (BN_cmp(two_powN, dh->params.q) < 0)
8083fd3a SL	269	upper = two_powN;
b128abc3	270	}
8083fd3a SL	271	if (!ffc_validate_private_key(upper, priv_key, ret))
8083fd3a SL	272	goto err;
b128abc3	273
0f113f3e	274	ok = 1;
8083fd3a SL	275	err:
8083fd3a SL	276	BN_free(two_powN);
26a7d938	277	return ok;
0f113f3e	278	}
8083fd3a SL	279
	280	/*
	281	* FFC pairwise check from SP800-56A R3.
	282	* Section 5.6.2.1.4 Owner Assurance of Pair-wise Consistency
	283	*/
	284	int dh_check_pairwise(DH *dh)
	285	{
	286	int ret = 0;
	287	BN_CTX *ctx = NULL;
	288	BIGNUM *pub_key = NULL;
	289
	290	if (dh->params.p == NULL
	291	\|\| dh->params.g == NULL
	292	\|\| dh->priv_key == NULL
	293	\|\| dh->pub_key == NULL)
	294	return 0;
	295
	296	ctx = BN_CTX_new_ex(dh->libctx);
	297	if (ctx == NULL)
	298	goto err;
	299	pub_key = BN_new();
	300	if (pub_key == NULL)
	301	goto err;
	302
	303	/* recalculate the public key = (g ^ priv) mod p */
	304	if (!dh_generate_public_key(ctx, dh, dh->priv_key, pub_key))
	305	goto err;
	306	/* check it matches the existing pubic_key */
	307	ret = BN_cmp(pub_key, dh->pub_key) == 0;
	308	err:
	309	BN_free(pub_key);
	310	BN_CTX_free(ctx);
	311	return ret;
	312	}