1/*
2 * Copyright 2016 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 <openssl/dh.h>
11#include "internal/refcount.h"
12
13#define DH_MIN_MODULUS_BITS 512
14
15struct dh_st {
16 /*
17 * This first argument is used to pick up errors when a DH is passed
18 * instead of a EVP_PKEY
19 */
20 int pad;
21 int version;
22 BIGNUM *p;
23 BIGNUM *g;
24 int32_t length; /* optional */
25 BIGNUM *pub_key; /* g^x % p */
26 BIGNUM *priv_key; /* x */
27 int flags;
28 BN_MONT_CTX *method_mont_p;
29 /* Place holders if we want to do X9.42 DH */
30 BIGNUM *q;
31 BIGNUM *j;
32 unsigned char *seed;
33 int seedlen;
34 BIGNUM *counter;
35 CRYPTO_REF_COUNT references;
36 CRYPTO_EX_DATA ex_data;
37 const DH_METHOD *meth;
38 ENGINE *engine;
39 CRYPTO_RWLOCK *lock;
40
41 /* Provider data */
42 size_t dirty_cnt; /* If any key material changes, increment this */
43};
44
45struct dh_method {
46 char *name;
47 /* Methods here */
48 int (*generate_key) (DH *dh);
49 int (*compute_key) (unsigned char *key, const BIGNUM *pub_key, DH *dh);
50
51 /* Can be null */
52 int (*bn_mod_exp) (const DH *dh, BIGNUM *r, const BIGNUM *a,
53 const BIGNUM *p, const BIGNUM *m, BN_CTX *ctx,
54 BN_MONT_CTX *m_ctx);
55 int (*init) (DH *dh);
56 int (*finish) (DH *dh);
57 int flags;
58 char *app_data;
59 /* If this is non-NULL, it will be used to generate parameters */
60 int (*generate_params) (DH *dh, int prime_len, int generator,
61 BN_GENCB *cb);
62};
63
64int dh_buf2key(DH *key, const unsigned char *buf, size_t len);
65size_t dh_key2buf(const DH *dh, unsigned char **pbuf);
66