1DH_GET0_PQG(3ossl) OpenSSL DH_GET0_PQG(3ossl)
2
6 DH_get0_pqg, DH_set0_pqg, DH_get0_key, DH_set0_key, DH_get0_p,
7 DH_get0_q, DH_get0_g, DH_get0_priv_key, DH_get0_pub_key,
8 DH_clear_flags, DH_test_flags, DH_set_flags, DH_get0_engine,
9 DH_get_length, DH_set_length - Routines for getting and setting data in
10 a DH object
11
13 #include <openssl/dh.h>
14 The following functions have been deprecated since OpenSSL 3.0, and can
16 be hidden entirely by defining OPENSSL_API_COMPAT with a suitable
17 version value, see openssl_user_macros(7):
18 void DH_get0_pqg(const DH *dh,
20 const BIGNUM **p, const BIGNUM **q, const BIGNUM **g);
21 int DH_set0_pqg(DH *dh, BIGNUM *p, BIGNUM *q, BIGNUM *g);
22 void DH_get0_key(const DH *dh,
23 const BIGNUM **pub_key, const BIGNUM **priv_key);
24 int DH_set0_key(DH *dh, BIGNUM *pub_key, BIGNUM *priv_key);
25 const BIGNUM *DH_get0_p(const DH *dh);
26 const BIGNUM *DH_get0_q(const DH *dh);
27 const BIGNUM *DH_get0_g(const DH *dh);
28 const BIGNUM *DH_get0_priv_key(const DH *dh);
29 const BIGNUM *DH_get0_pub_key(const DH *dh);
30 void DH_clear_flags(DH *dh, int flags);
31 int DH_test_flags(const DH *dh, int flags);
32 void DH_set_flags(DH *dh, int flags);
33 long DH_get_length(const DH *dh);
35 int DH_set_length(DH *dh, long length);
36 ENGINE *DH_get0_engine(DH *d);
38
40 All of the functions described on this page are deprecated.
41 Applications should instead use EVP_PKEY_get_bn_param(3) for any
42 methods that return a BIGNUM. Refer to EVP_PKEY-DH(7) for more
43 infomation.
44 A DH object contains the parameters p, q and g. Note that the q
46 parameter is optional. It also contains a public key (pub_key) and
47 (optionally) a private key (priv_key).
48 The p, q and g parameters can be obtained by calling DH_get0_pqg(). If
50 the parameters have not yet been set then *p, *q and *g will be set to
51 NULL. Otherwise they are set to pointers to their respective values.
52 These point directly to the internal representations of the values and
53 therefore should not be freed directly. Any of the out parameters p,
54 q, and g can be NULL, in which case no value will be returned for that
55 parameter.
56 The p, q and g values can be set by calling DH_set0_pqg() and passing
58 the new values for p, q and g as parameters to the function. Calling
59 this function transfers the memory management of the values to the DH
60 object, and therefore the values that have been passed in should not be
61 freed directly after this function has been called. The q parameter may
62 be NULL. DH_set0_pqg() also checks if the parameters associated with p
63 and g and optionally q are associated with known safe prime groups. If
64 it is a safe prime group then the value of q will be set to q = (p - 1)
65 / 2 if q is NULL. The optional length parameter will be set to
66 BN_num_bits(q) if q is not NULL.
67 To get the public and private key values use the DH_get0_key()
69 function. A pointer to the public key will be stored in *pub_key, and a
70 pointer to the private key will be stored in *priv_key. Either may be
71 NULL if they have not been set yet, although if the private key has
72 been set then the public key must be. The values point to the internal
73 representation of the public key and private key values. This memory
74 should not be freed directly. Any of the out parameters pub_key and
75 priv_key can be NULL, in which case no value will be returned for that
76 parameter.
77 The public and private key values can be set using DH_set0_key().
79 Either parameter may be NULL, which means the corresponding DH field is
80 left untouched. As with DH_set0_pqg() this function transfers the
81 memory management of the key values to the DH object, and therefore
82 they should not be freed directly after this function has been called.
83 Any of the values p, q, g, priv_key, and pub_key can also be retrieved
85 separately by the corresponding function DH_get0_p(), DH_get0_q(),
86 DH_get0_g(), DH_get0_priv_key(), and DH_get0_pub_key(), respectively.
87 DH_set_flags() sets the flags in the flags parameter on the DH object.
89 Multiple flags can be passed in one go (bitwise ORed together). Any
90 flags that are already set are left set. DH_test_flags() tests to see
91 whether the flags passed in the flags parameter are currently set in
92 the DH object. Multiple flags can be tested in one go. All flags that
93 are currently set are returned, or zero if none of the flags are set.
94 DH_clear_flags() clears the specified flags within the DH object.
95 DH_get0_engine() returns a handle to the ENGINE that has been set for
97 this DH object, or NULL if no such ENGINE has been set. This function
98 is deprecated. All engines should be replaced by providers.
99 The DH_get_length() and DH_set_length() functions get and set the
101 optional length parameter associated with this DH object. If the length
102 is nonzero then it is used, otherwise it is ignored. The length
103 parameter indicates the length of the secret exponent (private key) in
104 bits. For safe prime groups the optional length parameter length can be
105 set to a value greater or equal to 2 *
106 maximum_target_security_strength(BN_num_bits(p)) as listed in
107 SP800-56Ar3 Table(s) 25 & 26. These functions are deprecated and
108 should be replaced with EVP_PKEY_CTX_set_params() and
109 EVP_PKEY_get_int_param() using the parameter key
110 OSSL_PKEY_PARAM_DH_PRIV_LEN as described in EVP_PKEY-DH(7).
111
113 Values retrieved with DH_get0_key() are owned by the DH object used in
114 the call and may therefore not be passed to DH_set0_key(). If needed,
115 duplicate the received value using BN_dup() and pass the duplicate.
116 The same applies to DH_get0_pqg() and DH_set0_pqg().
117
119 DH_set0_pqg() and DH_set0_key() return 1 on success or 0 on failure.
120 DH_get0_p(), DH_get0_q(), DH_get0_g(), DH_get0_priv_key(), and
122 DH_get0_pub_key() return the respective value, or NULL if it is unset.
123 DH_test_flags() returns the current state of the flags in the DH
125 object.
126 DH_get0_engine() returns the ENGINE set for the DH object or NULL if no
128 ENGINE has been set.
129 DH_get_length() returns the length of the secret exponent (private key)
131 in bits, or zero if no such length has been explicitly set.
132
134 DH_new(3), DH_new(3), DH_generate_parameters(3), DH_generate_key(3),
135 DH_set_method(3), DH_size(3), DH_meth_new(3)
136
138 The functions described here were added in OpenSSL 1.1.0.
139 All of these functions were deprecated in OpenSSL 3.0.
141
143 Copyright 2016-2021 The OpenSSL Project Authors. All Rights Reserved.
144 Licensed under the Apache License 2.0 (the "License"). You may not use
146 this file except in compliance with the License. You can obtain a copy
147 in the file LICENSE in the source distribution or at
148 <https://www.openssl.org/source/license.html>.
1493.0.5 2022-11-01 DH_GET0_PQG(3ossl)