1DSA_METH_NEW(3)                     OpenSSL                    DSA_METH_NEW(3)
2
3
4

NAME

6       DSA_meth_new, DSA_meth_free, DSA_meth_dup, DSA_meth_get0_name,
7       DSA_meth_set1_name, DSA_meth_get_flags, DSA_meth_set_flags,
8       DSA_meth_get0_app_data, DSA_meth_set0_app_data, DSA_meth_get_sign,
9       DSA_meth_set_sign, DSA_meth_get_sign_setup, DSA_meth_set_sign_setup,
10       DSA_meth_get_verify, DSA_meth_set_verify, DSA_meth_get_mod_exp,
11       DSA_meth_set_mod_exp, DSA_meth_get_bn_mod_exp, DSA_meth_set_bn_mod_exp,
12       DSA_meth_get_init, DSA_meth_set_init, DSA_meth_get_finish,
13       DSA_meth_set_finish, DSA_meth_get_paramgen, DSA_meth_set_paramgen,
14       DSA_meth_get_keygen, DSA_meth_set_keygen - Routines to build up DSA
15       methods
16

SYNOPSIS

18        #include <openssl/dsa.h>
19
20        DSA_METHOD *DSA_meth_new(const char *name, int flags);
21
22        void DSA_meth_free(DSA_METHOD *dsam);
23
24        DSA_METHOD *DSA_meth_dup(const DSA_METHOD *meth);
25
26        const char *DSA_meth_get0_name(const DSA_METHOD *dsam);
27        int DSA_meth_set1_name(DSA_METHOD *dsam, const char *name);
28
29        int DSA_meth_get_flags(const DSA_METHOD *dsam);
30        int DSA_meth_set_flags(DSA_METHOD *dsam, int flags);
31
32        void *DSA_meth_get0_app_data(const DSA_METHOD *dsam);
33        int DSA_meth_set0_app_data(DSA_METHOD *dsam, void *app_data);
34
35        DSA_SIG *(*DSA_meth_get_sign(const DSA_METHOD *dsam))(const unsigned char *,
36                                                              int, DSA *);
37        int DSA_meth_set_sign(DSA_METHOD *dsam, DSA_SIG *(*sign)(const unsigned char *,
38                                                                 int, DSA *));
39
40        int (*DSA_meth_get_sign_setup(const DSA_METHOD *dsam))(DSA *, BN_CTX *,$
41                                                               BIGNUM **, BIGNUM **);
42        int DSA_meth_set_sign_setup(DSA_METHOD *dsam, int (*sign_setup)(DSA *, BN_CTX *,
43                                                                        BIGNUM **, BIGNUM **));
44
45        int (*DSA_meth_get_verify(const DSA_METHOD *dsam))(const unsigned char *,
46                                                           int, DSA_SIG *, DSA *);
47        int DSA_meth_set_verify(DSA_METHOD *dsam, int (*verify)(const unsigned char *,
48                                                                int, DSA_SIG *, DSA *));
49
50        int (*DSA_meth_get_mod_exp(const DSA_METHOD *dsam))(DSA *dsa, BIGNUM *rr, BIGNUM *a1,
51                                                            BIGNUM *p1, BIGNUM *a2, BIGNUM *p2,
52                                                            BIGNUM *m, BN_CTX *ctx,
53                                                            BN_MONT_CTX *in_mont);
54        int DSA_meth_set_mod_exp(DSA_METHOD *dsam, int (*mod_exp)(DSA *dsa, BIGNUM *rr,
55                                                                  BIGNUM *a1, BIGNUM *p1,
56                                                                  BIGNUM *a2, BIGNUM *p2,
57                                                                  BIGNUM *m, BN_CTX *ctx,
58                                                                  BN_MONT_CTX *mont));
59
60        int (*DSA_meth_get_bn_mod_exp(const DSA_METHOD *dsam))(DSA *dsa, BIGNUM *r, BIGNUM *a,
61                                                               const BIGNUM *p, const BIGNUM *m,
62                                                               BN_CTX *ctx, BN_MONT_CTX *mont);
63        int DSA_meth_set_bn_mod_exp(DSA_METHOD *dsam, int (*bn_mod_exp)(DSA *dsa,
64                                                                        BIGNUM *r,
65                                                                        BIGNUM *a,
66                                                                        const BIGNUM *p,
67                                                                        const BIGNUM *m,
68                                                                        BN_CTX *ctx,
69                                                                        BN_MONT_CTX *mont));
70
71        int (*DSA_meth_get_init(const DSA_METHOD *dsam))(DSA *);
72        int DSA_meth_set_init(DSA_METHOD *dsam, int (*init)(DSA *));
73
74        int (*DSA_meth_get_finish(const DSA_METHOD *dsam))(DSA *);
75        int DSA_meth_set_finish(DSA_METHOD *dsam, int (*finish)(DSA *));
76
77        int (*DSA_meth_get_paramgen(const DSA_METHOD *dsam))(DSA *, int,
78                                                             const unsigned char *,
79                                                             int, int *, unsigned long *,
80                                                             BN_GENCB *);
81        int DSA_meth_set_paramgen(DSA_METHOD *dsam,
82                                  int (*paramgen)(DSA *, int, const unsigned char *,
83                                                  int, int *, unsigned long *, BN_GENCB *));
84
85        int (*DSA_meth_get_keygen(const DSA_METHOD *dsam))(DSA *);
86        int DSA_meth_set_keygen(DSA_METHOD *dsam, int (*keygen)(DSA *));
87

DESCRIPTION

89       The DSA_METHOD type is a structure used for the provision of custom DSA
90       implementations. It provides a set of functions used by OpenSSL for the
91       implementation of the various DSA capabilities. See the dsa page for
92       more information.
93
94       DSA_meth_new() creates a new DSA_METHOD structure. It should be given a
95       unique name and a set of flags. The name should be a NULL terminated
96       string, which will be duplicated and stored in the DSA_METHOD object.
97       It is the callers responsibility to free the original string. The flags
98       will be used during the construction of a new DSA object based on this
99       DSA_METHOD. Any new DSA object will have those flags set by default.
100
101       DSA_meth_dup() creates a duplicate copy of the DSA_METHOD object passed
102       as a parameter. This might be useful for creating a new DSA_METHOD
103       based on an existing one, but with some differences.
104
105       DSA_meth_free() destroys a DSA_METHOD structure and frees up any memory
106       associated with it.
107
108       DSA_meth_get0_name() will return a pointer to the name of this
109       DSA_METHOD. This is a pointer to the internal name string and so should
110       not be freed by the caller. DSA_meth_set1_name() sets the name of the
111       DSA_METHOD to name. The string is duplicated and the copy is stored in
112       the DSA_METHOD structure, so the caller remains responsible for freeing
113       the memory associated with the name.
114
115       DSA_meth_get_flags() returns the current value of the flags associated
116       with this DSA_METHOD. DSA_meth_set_flags() provides the ability to set
117       these flags.
118
119       The functions DSA_meth_get0_app_data() and DSA_meth_set0_app_data()
120       provide the ability to associate implementation specific data with the
121       DSA_METHOD. It is the application's responsibility to free this data
122       before the DSA_METHOD is freed via a call to DSA_meth_free().
123
124       DSA_meth_get_sign() and DSA_meth_set_sign() get and set the function
125       used for creating a DSA signature respectively. This function will be
126       called in response to the application calling DSA_do_sign() (or
127       DSA_sign()). The parameters for the function have the same meaning as
128       for DSA_do_sign().
129
130       DSA_meth_get_sign_setup() and DSA_meth_set_sign_setup() get and set the
131       function used for precalculating the DSA signature values k^-1 and r.
132       This function will be called in response to the application calling
133       DSA_sign_setup(). The parameters for the function have the same meaning
134       as for DSA_sign_setup().
135
136       DSA_meth_get_verify() and DSA_meth_set_verify() get and set the
137       function used for verifying a DSA signature respectively. This function
138       will be called in response to the application calling DSA_do_verify()
139       (or DSA_verify()). The parameters for the function have the same
140       meaning as for DSA_do_verify().
141
142       DSA_meth_get_mod_exp() and DSA_meth_set_mod_exp() get and set the
143       function used for computing the following value:
144
145        rr = a1^p1 * a2^p2 mod m
146
147       This function will be called by the default OpenSSL method during
148       verification of a DSA signature. The result is stored in the rr
149       parameter. This function may be NULL.
150
151       DSA_meth_get_bn_mod_exp() and DSA_meth_set_bn_mod_exp() get and set the
152       function used for computing the following value:
153
154        r = a ^ p mod m
155
156       This function will be called by the default OpenSSL function for
157       DSA_sign_setup(). The result is stored in the r parameter. This
158       function may be NULL.
159
160       DSA_meth_get_init() and DSA_meth_set_init() get and set the function
161       used for creating a new DSA instance respectively. This function will
162       be called in response to the application calling DSA_new() (if the
163       current default DSA_METHOD is this one) or DSA_new_method(). The
164       DSA_new() and DSA_new_method() functions will allocate the memory for
165       the new DSA object, and a pointer to this newly allocated structure
166       will be passed as a parameter to the function. This function may be
167       NULL.
168
169       DSA_meth_get_finish() and DSA_meth_set_finish() get and set the
170       function used for destroying an instance of a DSA object respectively.
171       This function will be called in response to the application calling
172       DSA_free(). A pointer to the DSA to be destroyed is passed as a
173       parameter. The destroy function should be used for DSA implementation
174       specific clean up. The memory for the DSA itself should not be freed by
175       this function. This function may be NULL.
176
177       DSA_meth_get_paramgen() and DSA_meth_set_paramgen() get and set the
178       function used for generating DSA parameters respectively. This function
179       will be called in response to the application calling
180       DSA_generate_parameters_ex() (or DSA_generate_parameters()). The
181       parameters for the function have the same meaning as for
182       DSA_generate_parameters_ex().
183
184       DSA_meth_get_keygen() and DSA_meth_set_keygen() get and set the
185       function used for generating a new DSA key pair respectively. This
186       function will be called in response to the application calling
187       DSA_generate_key(). The parameter for the function has the same meaning
188       as for DSA_generate_key().
189

RETURN VALUES

191       DSA_meth_new() and DSA_meth_dup() return the newly allocated DSA_METHOD
192       object or NULL on failure.
193
194       DSA_meth_get0_name() and DSA_meth_get_flags() return the name and flags
195       associated with the DSA_METHOD respectively.
196
197       All other DSA_meth_get_*() functions return the appropriate function
198       pointer that has been set in the DSA_METHOD, or NULL if no such pointer
199       has yet been set.
200
201       DSA_meth_set1_name() and all DSA_meth_set_*() functions return 1 on
202       success or 0 on failure.
203

SEE ALSO

205       DSA_new(3), DSA_new(3), DSA_generate_parameters(3),
206       DSA_generate_key(3), DSA_dup_DH(3), DSA_do_sign(3), DSA_set_method(3),
207       DSA_SIG_new(3), DSA_sign(3), DSA_size(3), DSA_get0_pqg(3)
208

HISTORY

210       The functions described here were added in OpenSSL 1.1.0.
211
213       Copyright 2016-2018 The OpenSSL Project Authors. All Rights Reserved.
214
215       Licensed under the OpenSSL license (the "License").  You may not use
216       this file except in compliance with the License.  You can obtain a copy
217       in the file LICENSE in the source distribution or at
218       <https://www.openssl.org/source/license.html>.
219
220
221
2221.1.1q                            2022-07-07                   DSA_METH_NEW(3)
Impressum