EVP_ASYM_CIPHER_FREE(3)

NAME
EVP_ASYM_CIPHER_fetch, EVP_ASYM_CIPHER_free, EVP_ASYM_CIPHER_up_ref, EVP_ASYM_CIPHER_number, EVP_ASYM_CIPHER_is_a, EVP_ASYM_CIPHER_provider, EVP_ASYM_CIPHER_do_all_provided, EVP_ASYM_CIPHER_names_do_all - Functions to manage EVP_ASYM_CIPHER algorithm objects

SYNOPSIS
 #include <openssl/evp.h>

 EVP_ASYM_CIPHER *EVP_ASYM_CIPHER_fetch(OPENSSL_CTX *ctx, const char *algorithm,
                                        const char *properties);
 void EVP_ASYM_CIPHER_free(EVP_ASYM_CIPHER *cipher);
 int EVP_ASYM_CIPHER_up_ref(EVP_ASYM_CIPHER *cipher);
 int EVP_ASYM_CIPHER_number(const EVP_ASYM_CIPHER *cipher);
 int EVP_ASYM_CIPHER_is_a(const EVP_ASYM_CIPHER *cipher, const char *name);
 OSSL_PROVIDER *EVP_ASYM_CIPHER_provider(const EVP_ASYM_CIPHER *cipher);
 void EVP_ASYM_CIPHER_do_all_provided(OPENSSL_CTX *libctx,
                                      void (*fn)(EVP_ASYM_CIPHER *cipher,
                                                 void *arg),
                                      void *arg);
 void EVP_ASYM_CIPHER_names_do_all(const EVP_ASYM_CIPHER *cipher,
                                   void (*fn)(const char *name, void *data),
                                   void *data);

DESCRIPTION
EVP_ASYM_CIPHER_fetch() fetches the implementation for the given algorithm from any provider offering it, within the criteria given by the properties and in the scope of the given library context ctx (see OPENSSL_CTX(3)). The algorithm will be one offering functions for performing asymmetric cipher related tasks such as asymmetric encryption and decryption. See "Fetching algorithms" in provider(7) for further information.

The returned value must eventually be freed with EVP_ASYM_CIPHER_free().

EVP_ASYM_CIPHER_free() decrements the reference count for the EVP_ASYM_CIPHER structure. Typically this structure will have been obtained from an earlier call to EVP_ASYM_CIPHER_fetch(). If the reference count drops to 0 then the structure is freed.

EVP_ASYM_CIPHER_up_ref() increments the reference count for an EVP_ASYM_CIPHER structure.

EVP_ASYM_CIPHER_is_a() returns 1 if cipher is an implementation of an algorithm that's identifiable with name, otherwise 0.

EVP_ASYM_CIPHER_provider() returns the provider that cipher was fetched from.

EVP_ASYM_CIPHER_do_all_provided() traverses all EVP_ASYM_CIPHERs implemented by all activated providers in the given library context libctx, and for each of the implementations, calls the given function fn with the implementation method and the given arg as argument.

EVP_ASYM_CIPHER_number() returns the internal dynamic number assigned to cipher.

EVP_ASYM_CIPHER_names_do_all() traverses all names for cipher, and calls fn with each name and data.

RETURN VALUES
EVP_ASYM_CIPHER_fetch() returns a pointer to an EVP_ASYM_CIPHER for success or NULL for failure.

EVP_ASYM_CIPHER_up_ref() returns 1 for success or 0 otherwise.

SEE ALSO
"Fetching algorithms" in provider(7), OSSL_PROVIDER(3)

HISTORY
The functions described here were added in OpenSSL 3.0.

COPYRIGHT
Copyright 2019 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the Apache License 2.0 (the "License"). You may not use this file except in compliance with the License. You can obtain a copy in the file LICENSE in the source distribution or at <https://www.openssl.org/source/license.html>.