openssl/crypto/dh/dh_rfc7919.c

75 lines
2.0 KiB
C

/*
* Copyright 2017 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (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 <stdio.h>
#include "internal/cryptlib.h"
#include "dh_local.h"
#include <openssl/bn.h>
#include <openssl/objects.h>
#include "crypto/bn_dh.h"
static DH *dh_param_init(const BIGNUM *p, int32_t nbits)
{
DH *dh = DH_new();
if (dh == NULL)
return NULL;
dh->p = (BIGNUM *)p;
dh->g = (BIGNUM *)&_bignum_const_2;
dh->length = nbits;
return dh;
}
DH *DH_new_by_nid(int nid)
{
switch (nid) {
case NID_ffdhe2048:
return dh_param_init(&_bignum_ffdhe2048_p, 225);
case NID_ffdhe3072:
return dh_param_init(&_bignum_ffdhe3072_p, 275);
case NID_ffdhe4096:
return dh_param_init(&_bignum_ffdhe4096_p, 325);
case NID_ffdhe6144:
return dh_param_init(&_bignum_ffdhe6144_p, 375);
case NID_ffdhe8192:
return dh_param_init(&_bignum_ffdhe8192_p, 400);
default:
DHerr(DH_F_DH_NEW_BY_NID, DH_R_INVALID_PARAMETER_NID);
return NULL;
}
}
int DH_get_nid(const DH *dh)
{
int nid;
if (BN_get_word(dh->g) != 2)
return NID_undef;
if (!BN_cmp(dh->p, &_bignum_ffdhe2048_p))
nid = NID_ffdhe2048;
else if (!BN_cmp(dh->p, &_bignum_ffdhe3072_p))
nid = NID_ffdhe3072;
else if (!BN_cmp(dh->p, &_bignum_ffdhe4096_p))
nid = NID_ffdhe4096;
else if (!BN_cmp(dh->p, &_bignum_ffdhe6144_p))
nid = NID_ffdhe6144;
else if (!BN_cmp(dh->p, &_bignum_ffdhe8192_p))
nid = NID_ffdhe8192;
else
return NID_undef;
if (dh->q != NULL) {
BIGNUM *q = BN_dup(dh->p);
/* Check q = p * 2 + 1 we already know q is odd, so just shift right */
if (q == NULL || !BN_rshift1(q, q) || !BN_cmp(dh->q, q))
nid = NID_undef;
BN_free(q);
}
return nid;
}