1DH_METH_NEW(3) OpenSSL DH_METH_NEW(3)
2
6 DH_meth_new, DH_meth_free, DH_meth_dup, DH_meth_get0_name,
7 DH_meth_set1_name, DH_meth_get_flags, DH_meth_set_flags,
8 DH_meth_get0_app_data, DH_meth_set0_app_data, DH_meth_get_generate_key,
9 DH_meth_set_generate_key, DH_meth_get_compute_key,
10 DH_meth_set_compute_key, DH_meth_get_bn_mod_exp,
11 DH_meth_set_bn_mod_exp, DH_meth_get_init, DH_meth_set_init,
12 DH_meth_get_finish, DH_meth_set_finish, DH_meth_get_generate_params,
13 DH_meth_set_generate_params - Routines to build up DH methods
14
16 #include <openssl/dh.h>
17 DH_METHOD *DH_meth_new(const char *name, int flags);
19 void DH_meth_free(DH_METHOD *dhm);
21 DH_METHOD *DH_meth_dup(const DH_METHOD *dhm);
23 const char *DH_meth_get0_name(const DH_METHOD *dhm);
25 int DH_meth_set1_name(DH_METHOD *dhm, const char *name);
26 int DH_meth_get_flags(const DH_METHOD *dhm);
28 int DH_meth_set_flags(DH_METHOD *dhm, int flags);
29 void *DH_meth_get0_app_data(const DH_METHOD *dhm);
31 int DH_meth_set0_app_data(DH_METHOD *dhm, void *app_data);
32 int (*DH_meth_get_generate_key(const DH_METHOD *dhm))(DH *);
34 int DH_meth_set_generate_key(DH_METHOD *dhm, int (*generate_key)(DH *));
35 int (*DH_meth_get_compute_key(const DH_METHOD *dhm))
37 (unsigned char *key, const BIGNUM *pub_key, DH *dh);
38 int DH_meth_set_compute_key(DH_METHOD *dhm,
39 int (*compute_key)(unsigned char *key, const BIGNUM *pub_key, DH *dh));
40 int (*DH_meth_get_bn_mod_exp(const DH_METHOD *dhm))
42 (const DH *dh, BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
43 const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx);
44 int DH_meth_set_bn_mod_exp(DH_METHOD *dhm,
45 int (*bn_mod_exp)(const DH *dh, BIGNUM *r, const BIGNUM *a,
46 const BIGNUM *p, const BIGNUM *m, BN_CTX *ctx,
47 BN_MONT_CTX *m_ctx));
48 int (*DH_meth_get_init(const DH_METHOD *dhm))(DH *);
50 int DH_meth_set_init(DH_METHOD *dhm, int (*init)(DH *));
51 int (*DH_meth_get_finish(const DH_METHOD *dhm))(DH *);
53 int DH_meth_set_finish(DH_METHOD *dhm, int (*finish)(DH *));
54 int (*DH_meth_get_generate_params(const DH_METHOD *dhm))
56 (DH *, int, int, BN_GENCB *);
57 int DH_meth_set_generate_params(DH_METHOD *dhm,
58 int (*generate_params)(DH *, int, int, BN_GENCB *));
59
61 The DH_METHOD type is a structure used for the provision of custom DH
62 implementations. It provides a set of functions used by OpenSSL for the
63 implementation of the various DH capabilities.
64 DH_meth_new() creates a new DH_METHOD structure. It should be given a
66 unique name and a set of flags. The name should be a NULL terminated
67 string, which will be duplicated and stored in the DH_METHOD object. It
68 is the callers responsibility to free the original string. The flags
69 will be used during the construction of a new DH object based on this
70 DH_METHOD. Any new DH object will have those flags set by default.
71 DH_meth_dup() creates a duplicate copy of the DH_METHOD object passed
73 as a parameter. This might be useful for creating a new DH_METHOD based
74 on an existing one, but with some differences.
75 DH_meth_free() destroys a DH_METHOD structure and frees up any memory
77 associated with it.
78 DH_meth_get0_name() will return a pointer to the name of this
80 DH_METHOD. This is a pointer to the internal name string and so should
81 not be freed by the caller. DH_meth_set1_name() sets the name of the
82 DH_METHOD to name. The string is duplicated and the copy is stored in
83 the DH_METHOD structure, so the caller remains responsible for freeing
84 the memory associated with the name.
85 DH_meth_get_flags() returns the current value of the flags associated
87 with this DH_METHOD. DH_meth_set_flags() provides the ability to set
88 these flags.
89 The functions DH_meth_get0_app_data() and DH_meth_set0_app_data()
91 provide the ability to associate implementation specific data with the
92 DH_METHOD. It is the application's responsibility to free this data
93 before the DH_METHOD is freed via a call to DH_meth_free().
94 DH_meth_get_generate_key() and DH_meth_set_generate_key() get and set
96 the function used for generating a new DH key pair respectively. This
97 function will be called in response to the application calling
98 DH_generate_key(). The parameter for the function has the same meaning
99 as for DH_generate_key().
100 DH_meth_get_compute_key() and DH_meth_set_compute_key() get and set the
102 function used for computing a new DH shared secret respectively. This
103 function will be called in response to the application calling
104 DH_compute_key(). The parameters for the function have the same meaning
105 as for DH_compute_key().
106 DH_meth_get_bn_mod_exp() and DH_meth_set_bn_mod_exp() get and set the
108 function used for computing the following value:
109 r = a ^ p mod m
111 This function will be called by the default OpenSSL function for
113 DH_generate_key(). The result is stored in the r parameter. This
114 function may be NULL unless using the default generate key function, in
115 which case it must be present.
116 DH_meth_get_init() and DH_meth_set_init() get and set the function used
118 for creating a new DH instance respectively. This function will be
119 called in response to the application calling DH_new() (if the current
120 default DH_METHOD is this one) or DH_new_method(). The DH_new() and
121 DH_new_method() functions will allocate the memory for the new DH
122 object, and a pointer to this newly allocated structure will be passed
123 as a parameter to the function. This function may be NULL.
124 DH_meth_get_finish() and DH_meth_set_finish() get and set the function
126 used for destroying an instance of a DH object respectively. This
127 function will be called in response to the application calling
128 DH_free(). A pointer to the DH to be destroyed is passed as a
129 parameter. The destroy function should be used for DH implementation
130 specific clean up. The memory for the DH itself should not be freed by
131 this function. This function may be NULL.
132 DH_meth_get_generate_params() and DH_meth_set_generate_params() get and
134 set the function used for generating DH parameters respectively. This
135 function will be called in response to the application calling
136 DH_generate_parameters_ex() (or DH_generate_parameters()). The
137 parameters for the function have the same meaning as for
138 DH_generate_parameters_ex(). This function may be NULL.
139
141 DH_meth_new() and DH_meth_dup() return the newly allocated DH_METHOD
142 object or NULL on failure.
143 DH_meth_get0_name() and DH_meth_get_flags() return the name and flags
145 associated with the DH_METHOD respectively.
146 All other DH_meth_get_*() functions return the appropriate function
148 pointer that has been set in the DH_METHOD, or NULL if no such pointer
149 has yet been set.
150 DH_meth_set1_name() and all DH_meth_set_*() functions return 1 on
152 success or 0 on failure.
153
155 DH_new(3), DH_new(3), DH_generate_parameters(3), DH_generate_key(3),
156 DH_set_method(3), DH_size(3), DH_get0_pqg(3)
157
159 The functions described here were added in OpenSSL 1.1.0.
160
162 Copyright 2016-2018 The OpenSSL Project Authors. All Rights Reserved.
163 Licensed under the OpenSSL license (the "License"). You may not use
165 this file except in compliance with the License. You can obtain a copy
166 in the file LICENSE in the source distribution or at
167 <https://www.openssl.org/source/license.html>.
1681.1.1i 2021-07-22 DH_METH_NEW(3)