1=pod
2
3=head1 NAME
4
5DSA_meth_new, DSA_meth_free, DSA_meth_dup, DSA_meth_get0_name,
6DSA_meth_set1_name, DSA_meth_get_flags, DSA_meth_set_flags,
7DSA_meth_get0_app_data, DSA_meth_set0_app_data, DSA_meth_get_sign,
8DSA_meth_set_sign, DSA_meth_get_sign_setup, DSA_meth_set_sign_setup,
9DSA_meth_get_verify, DSA_meth_set_verify, DSA_meth_get_mod_exp,
10DSA_meth_set_mod_exp, DSA_meth_get_bn_mod_exp, DSA_meth_set_bn_mod_exp,
11DSA_meth_get_init, DSA_meth_set_init, DSA_meth_get_finish, DSA_meth_set_finish,
12DSA_meth_get_paramgen, DSA_meth_set_paramgen, DSA_meth_get_keygen,
13DSA_meth_set_keygen - Routines to build up DSA methods
14
15=head1 SYNOPSIS
16
17 #include <openssl/dsa.h>
18
19The following functions have been deprecated since OpenSSL 3.0, and can be
20hidden entirely by defining B<OPENSSL_API_COMPAT> with a suitable version value,
21see L<openssl_user_macros(7)>:
22
23 DSA_METHOD *DSA_meth_new(const char *name, int flags);
24
25 void DSA_meth_free(DSA_METHOD *dsam);
26
27 DSA_METHOD *DSA_meth_dup(const DSA_METHOD *meth);
28
29 const char *DSA_meth_get0_name(const DSA_METHOD *dsam);
30 int DSA_meth_set1_name(DSA_METHOD *dsam, const char *name);
31
32 int DSA_meth_get_flags(const DSA_METHOD *dsam);
33 int DSA_meth_set_flags(DSA_METHOD *dsam, int flags);
34
35 void *DSA_meth_get0_app_data(const DSA_METHOD *dsam);
36 int DSA_meth_set0_app_data(DSA_METHOD *dsam, void *app_data);
37
38 DSA_SIG *(*DSA_meth_get_sign(const DSA_METHOD *dsam))(const unsigned char *,
39                                                       int, DSA *);
40 int DSA_meth_set_sign(DSA_METHOD *dsam, DSA_SIG *(*sign)(const unsigned char *,
41                                                          int, DSA *));
42
43 int (*DSA_meth_get_sign_setup(const DSA_METHOD *dsam))(DSA *, BN_CTX *,$
44                                                        BIGNUM **, BIGNUM **);
45 int DSA_meth_set_sign_setup(DSA_METHOD *dsam, int (*sign_setup)(DSA *, BN_CTX *,
46                                                                 BIGNUM **, BIGNUM **));
47
48 int (*DSA_meth_get_verify(const DSA_METHOD *dsam))(const unsigned char *,
49                                                    int, DSA_SIG *, DSA *);
50 int DSA_meth_set_verify(DSA_METHOD *dsam, int (*verify)(const unsigned char *,
51                                                         int, DSA_SIG *, DSA *));
52
53 int (*DSA_meth_get_mod_exp(const DSA_METHOD *dsam))(DSA *dsa, BIGNUM *rr, BIGNUM *a1,
54                                                     BIGNUM *p1, BIGNUM *a2, BIGNUM *p2,
55                                                     BIGNUM *m, BN_CTX *ctx,
56                                                     BN_MONT_CTX *in_mont);
57 int DSA_meth_set_mod_exp(DSA_METHOD *dsam, int (*mod_exp)(DSA *dsa, BIGNUM *rr,
58                                                           BIGNUM *a1, BIGNUM *p1,
59                                                           BIGNUM *a2, BIGNUM *p2,
60                                                           BIGNUM *m, BN_CTX *ctx,
61                                                           BN_MONT_CTX *mont));
62
63 int (*DSA_meth_get_bn_mod_exp(const DSA_METHOD *dsam))(DSA *dsa, BIGNUM *r, BIGNUM *a,
64                                                        const BIGNUM *p, const BIGNUM *m,
65                                                        BN_CTX *ctx, BN_MONT_CTX *mont);
66 int DSA_meth_set_bn_mod_exp(DSA_METHOD *dsam, int (*bn_mod_exp)(DSA *dsa,
67                                                                 BIGNUM *r,
68                                                                 BIGNUM *a,
69                                                                 const BIGNUM *p,
70                                                                 const BIGNUM *m,
71                                                                 BN_CTX *ctx,
72                                                                 BN_MONT_CTX *mont));
73
74 int (*DSA_meth_get_init(const DSA_METHOD *dsam))(DSA *);
75 int DSA_meth_set_init(DSA_METHOD *dsam, int (*init)(DSA *));
76
77 int (*DSA_meth_get_finish(const DSA_METHOD *dsam))(DSA *);
78 int DSA_meth_set_finish(DSA_METHOD *dsam, int (*finish)(DSA *));
79
80 int (*DSA_meth_get_paramgen(const DSA_METHOD *dsam))(DSA *, int,
81                                                      const unsigned char *,
82                                                      int, int *, unsigned long *,
83                                                      BN_GENCB *);
84 int DSA_meth_set_paramgen(DSA_METHOD *dsam,
85                           int (*paramgen)(DSA *, int, const unsigned char *,
86                                           int, int *, unsigned long *, BN_GENCB *));
87
88 int (*DSA_meth_get_keygen(const DSA_METHOD *dsam))(DSA *);
89 int DSA_meth_set_keygen(DSA_METHOD *dsam, int (*keygen)(DSA *));
90
91=head1 DESCRIPTION
92
93All of the functions described on this page are deprecated.
94Applications and extension implementations should instead use the
95OSSL_PROVIDER APIs.
96
97The B<DSA_METHOD> type is a structure used for the provision of custom DSA
98implementations. It provides a set of functions used by OpenSSL for the
99implementation of the various DSA capabilities.
100
101DSA_meth_new() creates a new B<DSA_METHOD> structure. It should be given a
102unique B<name> and a set of B<flags>. The B<name> should be a NULL terminated
103string, which will be duplicated and stored in the B<DSA_METHOD> object. It is
104the callers responsibility to free the original string. The flags will be used
105during the construction of a new B<DSA> object based on this B<DSA_METHOD>. Any
106new B<DSA> object will have those flags set by default.
107
108DSA_meth_dup() creates a duplicate copy of the B<DSA_METHOD> object passed as a
109parameter. This might be useful for creating a new B<DSA_METHOD> based on an
110existing one, but with some differences.
111
112DSA_meth_free() destroys a B<DSA_METHOD> structure and frees up any memory
113associated with it.
114
115DSA_meth_get0_name() will return a pointer to the name of this DSA_METHOD. This
116is a pointer to the internal name string and so should not be freed by the
117caller. DSA_meth_set1_name() sets the name of the DSA_METHOD to B<name>. The
118string is duplicated and the copy is stored in the DSA_METHOD structure, so the
119caller remains responsible for freeing the memory associated with the name.
120
121DSA_meth_get_flags() returns the current value of the flags associated with this
122DSA_METHOD. DSA_meth_set_flags() provides the ability to set these flags.
123
124The functions DSA_meth_get0_app_data() and DSA_meth_set0_app_data() provide the
125ability to associate implementation specific data with the DSA_METHOD. It is
126the application's responsibility to free this data before the DSA_METHOD is
127freed via a call to DSA_meth_free().
128
129DSA_meth_get_sign() and DSA_meth_set_sign() get and set the function used for
130creating a DSA signature respectively. This function will be
131called in response to the application calling DSA_do_sign() (or DSA_sign()). The
132parameters for the function have the same meaning as for DSA_do_sign().
133
134DSA_meth_get_sign_setup() and DSA_meth_set_sign_setup() get and set the function
135used for precalculating the DSA signature values B<k^-1> and B<r>. This function
136will be called in response to the application calling DSA_sign_setup(). The
137parameters for the function have the same meaning as for DSA_sign_setup().
138
139DSA_meth_get_verify() and DSA_meth_set_verify() get and set the function used
140for verifying a DSA signature respectively. This function will be called in
141response to the application calling DSA_do_verify() (or DSA_verify()). The
142parameters for the function have the same meaning as for DSA_do_verify().
143
144DSA_meth_get_mod_exp() and DSA_meth_set_mod_exp() get and set the function used
145for computing the following value:
146
147 rr = a1^p1 * a2^p2 mod m
148
149This function will be called by the default OpenSSL method during verification
150of a DSA signature. The result is stored in the B<rr> parameter. This function
151may be NULL.
152
153DSA_meth_get_bn_mod_exp() and DSA_meth_set_bn_mod_exp() get and set the function
154used for computing the following value:
155
156 r = a ^ p mod m
157
158This function will be called by the default OpenSSL function for
159DSA_sign_setup(). The result is stored in the B<r> parameter. This function
160may be NULL.
161
162DSA_meth_get_init() and DSA_meth_set_init() get and set the function used
163for creating a new DSA instance respectively. This function will be
164called in response to the application calling DSA_new() (if the current default
165DSA_METHOD is this one) or DSA_new_method(). The DSA_new() and DSA_new_method()
166functions will allocate the memory for the new DSA object, and a pointer to this
167newly allocated structure will be passed as a parameter to the function. This
168function may be NULL.
169
170DSA_meth_get_finish() and DSA_meth_set_finish() get and set the function used
171for destroying an instance of a DSA object respectively. This function will be
172called in response to the application calling DSA_free(). A pointer to the DSA
173to be destroyed is passed as a parameter. The destroy function should be used
174for DSA implementation specific clean up. The memory for the DSA itself should
175not be freed by this function. This function may be NULL.
176
177DSA_meth_get_paramgen() and DSA_meth_set_paramgen() get and set the function
178used for generating DSA parameters respectively. This function will be called in
179response to the application calling DSA_generate_parameters_ex() (or
180DSA_generate_parameters()). The parameters for the function have the same
181meaning as for DSA_generate_parameters_ex().
182
183DSA_meth_get_keygen() and DSA_meth_set_keygen() get and set the function
184used for generating a new DSA key pair respectively. This function will be
185called in response to the application calling DSA_generate_key(). The parameter
186for the function has the same meaning as for DSA_generate_key().
187
188=head1 RETURN VALUES
189
190DSA_meth_new() and DSA_meth_dup() return the newly allocated DSA_METHOD object
191or NULL on failure.
192
193DSA_meth_get0_name() and DSA_meth_get_flags() return the name and flags
194associated with the DSA_METHOD respectively.
195
196All other DSA_meth_get_*() functions return the appropriate function pointer
197that has been set in the DSA_METHOD, or NULL if no such pointer has yet been
198set.
199
200DSA_meth_set1_name() and all DSA_meth_set_*() functions return 1 on success or
2010 on failure.
202
203=head1 SEE ALSO
204
205L<DSA_new(3)>, L<DSA_new(3)>, L<DSA_generate_parameters(3)>, L<DSA_generate_key(3)>,
206L<DSA_dup_DH(3)>, L<DSA_do_sign(3)>, L<DSA_set_method(3)>, L<DSA_SIG_new(3)>,
207L<DSA_sign(3)>, L<DSA_size(3)>, L<DSA_get0_pqg(3)>
208
209=head1 HISTORY
210
211The functions described here were deprecated in OpenSSL 3.0.
212
213The functions described here were added in OpenSSL 1.1.0.
214
215=head1 COPYRIGHT
216
217Copyright 2016-2021 The OpenSSL Project Authors. All Rights Reserved.
218
219Licensed under the Apache License 2.0 (the "License").  You may not use
220this file except in compliance with the License.  You can obtain a copy
221in the file LICENSE in the source distribution or at
222L<https://www.openssl.org/source/license.html>.
223
224=cut
225