DSA_METH_NEW(3ossl)

📦 version 3.5.0, in opensuse-leap 16.0

🌸 NAME 🌸

okay so bestie, you're on the DSA_METH_NEW(3ossl) page, and it's literally the whole friend group of routines that build up DSA methods. The squad is 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, and DSA_meth_set_keygen — all of them are routines to build up DSA methods. 💅

✨ SYNOPSIS ✨

first thing, bestie: these functions have been deprecated since OpenSSL 3.0, and they can be hidden entirely by defining OPENSSL_API_COMPAT with a suitable version value — see openssl_user_macros(7). 🫶

#include <openssl/dsa.h>

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 💖

okay so important vibe check first: all of the functions described on this page are deprecated. Applications and extension implementations should instead use the OSSL_PROVIDER APIs. No cap. 🫶

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-and-play DSA energy. ✨

  • DSA_meth_new() — creates a new DSA_METHOD structure. You give it 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 caller's 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, but make it custom. 💅
  • DSA_meth_free() — destroys a DSA_METHOD structure and frees up any memory associated with it. If the argument is NULL, nothing is done. 🧚
  • DSA_meth_get0_name() — returns 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(). 🦋
  • 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 🌈

the related-page squad is:

🦋 HISTORY 🦋

  • The functions described here were deprecated in OpenSSL 3.0. 😭
  • The functions described here were added in OpenSSL 1.1.0. 🌟

ok so the legal bit, and bestie i need you to actually read it, not just scroll past it 👀

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

that's the whole squad's work, 2016 through 2024, all rights reserved, no cap ✨

it's licensed under the Apache License 2.0 — yep, "the License" with a capital L, that's the one 💅 — and here's the catch, the real one:

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

fr fr, if you're not complying, you're not using it. no vibes-based licensing, okay? 🙈

and where do you find the actual license text? glad you asked:

like it's right there, zero excuses, go get it, it's giving "due diligence" and honestly that's iconic 👑

and that's a wrap on DSA_METH_NEW(3ossl)! 💫 this page is from OpenSSL 3.5.0, dated 2026-09-25 — screenshot it, cite it, print it out and put it on your wall, whatever feels right 🌈

go build something slay, bestie. mwah 💋🧚💜

📦 where this page comes from