1=pod 2 3=head1 NAME 4 5EVP_ASYM_CIPHER_fetch, EVP_ASYM_CIPHER_free, EVP_ASYM_CIPHER_up_ref, 6EVP_ASYM_CIPHER_is_a, EVP_ASYM_CIPHER_get0_provider, 7EVP_ASYM_CIPHER_do_all_provided, EVP_ASYM_CIPHER_names_do_all, 8EVP_ASYM_CIPHER_get0_name, EVP_ASYM_CIPHER_get0_description, 9EVP_ASYM_CIPHER_gettable_ctx_params, EVP_ASYM_CIPHER_settable_ctx_params 10- Functions to manage EVP_ASYM_CIPHER algorithm objects 11 12=head1 SYNOPSIS 13 14 #include <openssl/evp.h> 15 16 EVP_ASYM_CIPHER *EVP_ASYM_CIPHER_fetch(OSSL_LIB_CTX *ctx, const char *algorithm, 17 const char *properties); 18 void EVP_ASYM_CIPHER_free(EVP_ASYM_CIPHER *cipher); 19 int EVP_ASYM_CIPHER_up_ref(EVP_ASYM_CIPHER *cipher); 20 const char *EVP_ASYM_CIPHER_get0_name(const EVP_ASYM_CIPHER *cipher); 21 int EVP_ASYM_CIPHER_is_a(const EVP_ASYM_CIPHER *cipher, const char *name); 22 OSSL_PROVIDER *EVP_ASYM_CIPHER_get0_provider(const EVP_ASYM_CIPHER *cipher); 23 void EVP_ASYM_CIPHER_do_all_provided(OSSL_LIB_CTX *libctx, 24 void (*fn)(EVP_ASYM_CIPHER *cipher, 25 void *arg), 26 void *arg); 27 int EVP_ASYM_CIPHER_names_do_all(const EVP_ASYM_CIPHER *cipher, 28 void (*fn)(const char *name, void *data), 29 void *data); 30 const char *EVP_ASYM_CIPHER_get0_description(const EVP_ASYM_CIPHER *cipher); 31 const OSSL_PARAM *EVP_ASYM_CIPHER_gettable_ctx_params(const EVP_ASYM_CIPHER *cip); 32 const OSSL_PARAM *EVP_ASYM_CIPHER_settable_ctx_params(const EVP_ASYM_CIPHER *cip); 33 34=head1 DESCRIPTION 35 36EVP_ASYM_CIPHER_fetch() fetches the implementation for the given 37B<algorithm> from any provider offering it, within the criteria given 38by the B<properties> and in the scope of the given library context B<ctx> (see 39L<OSSL_LIB_CTX(3)>). The algorithm will be one offering functions for performing 40asymmetric cipher related tasks such as asymmetric encryption and decryption. 41See L<crypto(7)/ALGORITHM FETCHING> for further information. 42 43The returned value must eventually be freed with EVP_ASYM_CIPHER_free(). 44 45EVP_ASYM_CIPHER_free() decrements the reference count for the B<EVP_ASYM_CIPHER> 46structure. Typically this structure will have been obtained from an earlier call 47to EVP_ASYM_CIPHER_fetch(). If the reference count drops to 0 then the 48structure is freed. If the argument is NULL, nothing is done. 49 50EVP_ASYM_CIPHER_up_ref() increments the reference count for an 51B<EVP_ASYM_CIPHER> structure. 52 53EVP_ASYM_CIPHER_is_a() returns 1 if I<cipher> is an implementation of an 54algorithm that's identifiable with I<name>, otherwise 0. 55 56EVP_ASYM_CIPHER_get0_provider() returns the provider that I<cipher> was 57fetched from. 58 59EVP_ASYM_CIPHER_do_all_provided() traverses all EVP_ASYM_CIPHERs implemented by 60all activated providers in the given library context I<libctx>, and for each of 61the implementations, calls the given function I<fn> with the implementation 62method and the given I<arg> as argument. 63 64EVP_ASYM_CIPHER_get0_name() returns the algorithm name from the provided 65implementation for the given I<cipher>. Note that the I<cipher> may have 66multiple synonyms associated with it. In this case the first name from the 67algorithm definition is returned. Ownership of the returned string is retained 68by the I<cipher> object and should not be freed by the caller. 69 70EVP_ASYM_CIPHER_names_do_all() traverses all names for I<cipher>, and calls 71I<fn> with each name and I<data>. 72 73EVP_ASYM_CIPHER_get0_description() returns a description of the I<cipher>, 74meant for display and human consumption. The description is at the 75discretion of the I<cipher> implementation. 76 77EVP_ASYM_CIPHER_gettable_ctx_params() and EVP_ASYM_CIPHER_settable_ctx_params() 78return a constant L<OSSL_PARAM(3)> array that describes the names and types of key 79parameters that can be retrieved or set by a key encryption algorithm using 80L<EVP_PKEY_CTX_get_params(3)> and L<EVP_PKEY_CTX_set_params(3)>. 81 82=head1 RETURN VALUES 83 84EVP_ASYM_CIPHER_fetch() returns a pointer to an B<EVP_ASYM_CIPHER> for success 85or B<NULL> for failure. 86 87EVP_ASYM_CIPHER_up_ref() returns 1 for success or 0 otherwise. 88 89EVP_ASYM_CIPHER_names_do_all() returns 1 if the callback was called for all 90names. A return value of 0 means that the callback was not called for any names. 91 92EVP_ASYM_CIPHER_gettable_ctx_params() and EVP_ASYM_CIPHER_settable_ctx_params() 93return a constant L<OSSL_PARAM(3)> array or NULL on error. 94 95=head1 SEE ALSO 96 97L<crypto(7)/ALGORITHM FETCHING>, L<OSSL_PROVIDER(3)> 98 99=head1 HISTORY 100 101The functions described here were added in OpenSSL 3.0. 102 103=head1 COPYRIGHT 104 105Copyright 2019-2024 The OpenSSL Project Authors. All Rights Reserved. 106 107Licensed under the Apache License 2.0 (the "License"). You may not use 108this file except in compliance with the License. You can obtain a copy 109in the file LICENSE in the source distribution or at 110L<https://www.openssl.org/source/license.html>. 111 112=cut 113