DSA_METH_NEW(3ossl)

📦
version 15.1 · 3 versions
, in freebsd 15.1

okay so bestie 💖 this is DSA_METH_NEW(3ossl), the OpenSSL page for building up DSA methods, and it’s lowkey a whole customizable-method moment. no cap, there are a lot of functions here, but we’re gonna get through every single one together. ✨

🌸 NAME 🌸

DSA_meth_new, DSA_meth_free, DSA_meth_dup, DSA_meth_get0_name, DSA_meth_set1_name, DSA_meth_get_flags, DSA_meth_set_flags, DSA_meth_get0_app_data, DSA_meth_set0_app_data, DSA_meth_get_sign, DSA_meth_set_sign, DSA_meth_get_sign_setup, DSA_meth_set_sign_setup, DSA_meth_get_verify, DSA_meth_set_verify, DSA_meth_get_mod_exp, DSA_meth_set_mod_exp, DSA_meth_get_bn_mod_exp, DSA_meth_set_bn_mod_exp, DSA_meth_get_init, DSA_meth_set_init, DSA_meth_get_finish, DSA_meth_set_finish, DSA_meth_get_paramgen, DSA_meth_set_paramgen, DSA_meth_get_keygen, DSA_meth_set_keygen — Routines to build up DSA methods. 🎀

✨ SYNOPSIS ✨

        #include <openssl/dsa.h>
heads up bestie: The following functions have been deprecated since OpenSSL 3.0, and can be hidden entirely by defining OPENSSL_API_COMPAT with a suitable version value, see openssl_user_macros(7):
        DSA_METHOD *DSA_meth_new(const char *name, int flags);

        void DSA_meth_free(DSA_METHOD *dsam);

        DSA_METHOD *DSA_meth_dup(const DSA_METHOD *meth);

        const char *DSA_meth_get0_name(const DSA_METHOD *dsam);
        int DSA_meth_set1_name(DSA_METHOD *dsam, const char *name);

        int DSA_meth_get_flags(const DSA_METHOD *dsam);
        int DSA_meth_set_flags(DSA_METHOD *dsam, int flags);

        void *DSA_meth_get0_app_data(const DSA_METHOD *dsam);
        int DSA_meth_set0_app_data(DSA_METHOD *dsam, void *app_data);

        DSA_SIG *(*DSA_meth_get_sign(const DSA_METHOD *dsam))(const unsigned char *,
                                                              int, DSA *);
        int DSA_meth_set_sign(DSA_METHOD *dsam, DSA_SIG *(*sign)(const unsigned char *,
                                                                 int, DSA *));

        int (*DSA_meth_get_sign_setup(const DSA_METHOD *dsam))(DSA *, BN_CTX *,$
                                                               BIGNUM **, BIGNUM **);
        int DSA_meth_set_sign_setup(DSA_METHOD *dsam, int (*sign_setup)(DSA *, BN_CTX *,
                                                                        BIGNUM **, BIGNUM **));

        int (*DSA_meth_get_verify(const DSA_METHOD *dsam))(const unsigned char *,
                                                           int, DSA_SIG *, DSA *);
        int DSA_meth_set_verify(DSA_METHOD *dsam, int (*verify)(const unsigned char *,
                                                                int, DSA_SIG *, DSA *));

        int (*DSA_meth_get_mod_exp(const DSA_METHOD *dsam))(DSA *dsa, BIGNUM *rr, BIGNUM *a1,
                                                            BIGNUM *p1, BIGNUM *a2, BIGNUM *p2,
                                                            BIGNUM *m, BN_CTX *ctx,
                                                            BN_MONT_CTX *in_mont);
        int DSA_meth_set_mod_exp(DSA_METHOD *dsam, int (*mod_exp)(DSA *dsa, BIGNUM *rr,
                                                                  BIGNUM *a1, BIGNUM *p1,
                                                                  BIGNUM *a2, BIGNUM *p2,
                                                                  BIGNUM *m, BN_CTX *ctx,
                                                                  BN_MONT_CTX *mont));

        int (*DSA_meth_get_bn_mod_exp(const DSA_METHOD *dsam))(DSA *dsa, BIGNUM *r, BIGNUM *a,
                                                               const BIGNUM *p, const BIGNUM *m,
                                                               BN_CTX *ctx, BN_MONT_CTX *mont);
        int DSA_meth_set_bn_mod_exp(DSA_METHOD *dsam, int (*bn_mod_exp)(DSA *dsa,
                                                                        BIGNUM *r,
                                                                        BIGNUM *a,
                                                                        const BIGNUM *p,
                                                                        const BIGNUM *m,
                                                                        BN_CTX *ctx,
                                                                        BN_MONT_CTX *mont));

        int (*DSA_meth_get_init(const DSA_METHOD *dsam))(DSA *);
        int DSA_meth_set_init(DSA_METHOD *dsam, int (*init)(DSA *));

        int (*DSA_meth_get_finish(const DSA_METHOD *dsam))(DSA *);
        int DSA_meth_set_finish(DSA_METHOD *dsam, int (*finish)(DSA *));

        int (*DSA_meth_get_paramgen(const DSA_METHOD *dsam))(DSA *, int,
                                                             const unsigned char *,
                                                             int, int *, unsigned long *,
                                                             BN_GENCB *);
        int DSA_meth_set_paramgen(DSA_METHOD *dsam,
                                  int (*paramgen)(DSA *, int, const unsigned char *,
                                                  int, int *, unsigned long *, BN_GENCB *));

        int (*DSA_meth_get_keygen(const DSA_METHOD *dsam))(DSA *);
        int DSA_meth_set_keygen(DSA_METHOD *dsam, int (*keygen)(DSA *));

💅 DESCRIPTION 💅

deprecation station, bestie: All of the functions described on this page are deprecated. Applications and extension implementations should instead use the OSSL_PROVIDER APIs. periodt.

The DSA_METHOD type is a structure used for the provision of custom DSA implementations. It provides a set of functions used by OpenSSL for the implementation of the various DSA capabilities. it’s giving plug-in energy, fr fr.

  • DSA_meth_new() — creates a new DSA_METHOD structure. It should be given a unique name and a set of flags. The name should be a NULL terminated string, which will be duplicated and stored in the DSA_METHOD object. It is the callers responsibility to free the original string. The flags will be used during the construction of a new DSA object based on this DSA_METHOD. Any new DSA object will have those flags set by default. 🎀
  • DSA_meth_dup() — creates a duplicate copy of the DSA_METHOD object passed as a parameter. This might be useful for creating a new DSA_METHOD based on an existing one, but with some differences. clone era.
  • DSA_meth_free() — destroys a DSA_METHOD structure and frees up any memory associated with it. If the argument is NULL, nothing is done. bye bestie 👋
  • DSA_meth_get0_name() — will return a pointer to the name of this DSA_METHOD. This is a pointer to the internal name string and so should not be freed by the caller. DSA_meth_set1_name() sets the name of the DSA_METHOD to name. The string is duplicated and the copy is stored in the DSA_METHOD structure, so the caller remains responsible for freeing the memory associated with the name. 🏷️
  • DSA_meth_get_flags() — returns the current value of the flags associated with this DSA_METHOD. DSA_meth_set_flags() provides the ability to set these flags. 🚩
  • DSA_meth_get0_app_data() and DSA_meth_set0_app_data() — provide the ability to associate implementation specific data with the DSA_METHOD. It is the application's responsibility to free this data before the DSA_METHOD is freed via a call to DSA_meth_free(). don't leak it, bestie. 💀
  • DSA_meth_get_sign() and DSA_meth_set_sign() — get and set the function used for creating a DSA signature respectively. This function will be called in response to the application calling DSA_do_sign() (or DSA_sign()). The parameters for the function have the same meaning as for DSA_do_sign(). ✍️
  • DSA_meth_get_sign_setup() and DSA_meth_set_sign_setup() — get and set the function used for precalculating the DSA signature values k^-1 and r. This function will be called in response to the application calling DSA_sign_setup(). The parameters for the function have the same meaning as for DSA_sign_setup(). 🧮
  • DSA_meth_get_verify() and DSA_meth_set_verify() — get and set the function used for verifying a DSA signature respectively. This function will be called in response to the application calling DSA_do_verify() (or DSA_verify()). The parameters for the function have the same meaning as for DSA_do_verify(). ✅
  • DSA_meth_get_mod_exp() and DSA_meth_set_mod_exp() — get and set the function used for computing the following value:
rr = a1^p1 * a2^p2 mod m

This function will be called by the default OpenSSL method during verification of a DSA signature. The result is stored in the rr parameter. This function may be NULL. 🔥

  • DSA_meth_get_bn_mod_exp() and DSA_meth_set_bn_mod_exp() — get and set the function used for computing the following value:
r = a ^ p mod m

This function will be called by the default OpenSSL function for DSA_sign_setup(). The result is stored in the r parameter. This function may be NULL. ✨

  • DSA_meth_get_init() and DSA_meth_set_init() — get and set the function used for creating a new DSA instance respectively. This function will be called in response to the application calling DSA_new() (if the current default DSA_METHOD is this one) or DSA_new_method(). The DSA_new() and DSA_new_method() functions will allocate the memory for the new DSA object, and a pointer to this newly allocated structure will be passed as a parameter to the function. This function may be NULL. 🌱
  • DSA_meth_get_finish() and DSA_meth_set_finish() — get and set the function used for destroying an instance of a DSA object respectively. This function will be called in response to the application calling DSA_free(). A pointer to the DSA to be destroyed is passed as a parameter. The destroy function should be used for DSA implementation specific clean up. The memory for the DSA itself should not be freed by this function. This function may be NULL. 🧹
  • DSA_meth_get_paramgen() and DSA_meth_set_paramgen() — get and set the function used for generating DSA parameters respectively. This function will be called in response to the application calling DSA_generate_parameters_ex() (or DSA_generate_parameters()). The parameters for the function have the same meaning as for DSA_generate_parameters_ex(). 🛠️
  • DSA_meth_get_keygen() and DSA_meth_set_keygen() — get and set the function used for generating a new DSA key pair respectively. This function will be called in response to the application calling DSA_generate_key(). The parameter for the function has the same meaning as for DSA_generate_key(). 🔑

🎀 RETURN VALUES 🎀

  • DSA_meth_new() and DSA_meth_dup() — return the newly allocated DSA_METHOD object or NULL on failure. 💖
  • DSA_meth_get0_name() and DSA_meth_get_flags() — return the name and flags associated with the DSA_METHOD respectively. 🏷️🚩
  • all other DSA_meth_get_*() functions — return the appropriate function pointer that has been set in the DSA_METHOD, or NULL if no such pointer has yet been set. 👀
  • DSA_meth_set1_name() and all DSA_meth_set_*() functions — return 1 on success or 0 on failure. ✅

🦋 SEE ALSO 🦋

DSA_new(3), DSA_new(3), DSA_generate_parameters(3), DSA_generate_key(3), DSA_dup_DH(3), DSA_do_sign(3), DSA_set_method(3), DSA_SIG_new(3), DSA_sign(3), DSA_size(3), DSA_get0_pqg(3)

🌈 HISTORY 🌈

The functions described here were deprecated in OpenSSL 3.0. 🕰️

The functions described here were added in OpenSSL 1.1.0. ✨

okay bestie, legal moment, but make it cute 🎀

Copyright 2016-2024 The OpenSSL Project Authors. All Rights Reserved.

So basically the OpenSSL Project Authors own this, all rights reserved, from 2016 through 2024 — that's the whole squad, no cap. 👑

This file is licensed under the Apache License 2.0 (that's "the License" — capital L, it's giving main character energy ✨). And listen, the rule is real:

You may not use this file except in compliance with the License. 💀

So like, read the License before you go wild, fr fr. If you want a copy of it, it's literally right there in the file LICENSE in the source distribution, or you can grab it at https://www.openssl.org/source/license.html. Easy. 🦋

and that's the whole page, bestie — we ate and left no crumbs 🍓 the whole thing lives in DSA_METH_NEW(3ossl) from OpenSSL 3.5.6, dated 2026-04-07 💅 go forth and be iconic with your DSA_METH ✨🫶

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