1=pod 2 3=head1 NAME 4 5EVP_PKEY_CTX_set_params, 6EVP_PKEY_CTX_settable_params, 7EVP_PKEY_CTX_get_params, 8EVP_PKEY_CTX_gettable_params 9- provider parameter passing operations 10 11=head1 SYNOPSIS 12 13 #include <openssl/evp.h> 14 15 int EVP_PKEY_CTX_set_params(EVP_PKEY_CTX *ctx, const OSSL_PARAM *params); 16 const OSSL_PARAM *EVP_PKEY_CTX_settable_params(const EVP_PKEY_CTX *ctx); 17 int EVP_PKEY_CTX_get_params(EVP_PKEY_CTX *ctx, OSSL_PARAM *params); 18 const OSSL_PARAM *EVP_PKEY_CTX_gettable_params(const EVP_PKEY_CTX *ctx); 19 20=head1 DESCRIPTION 21 22The EVP_PKEY_CTX_get_params() and EVP_PKEY_CTX_set_params() functions allow 23transfer of arbitrary key parameters to and from providers. 24Not all parameters may be supported by all providers. 25See L<OSSL_PROVIDER(3)> for more information on providers. 26The I<params> field is a pointer to a list of B<OSSL_PARAM> structures, 27terminated with a L<OSSL_PARAM_END(3)> struct. 28See L<OSSL_PARAM(3)> for information about passing parameters. 29These functions must only be called after the EVP_PKEY_CTX has been initialised 30for use in an operation. 31These methods replace the EVP_PKEY_CTX_ctrl() mechanism. (EVP_PKEY_CTX_ctrl now 32calls these methods internally to interact with providers). 33 34EVP_PKEY_CTX_gettable_params() and EVP_PKEY_CTX_settable_params() get a 35constant L<OSSL_PARAM(3)> array that describes the gettable and 36settable parameters for the current algorithm implementation, i.e. parameters 37that can be used with EVP_PKEY_CTX_get_params() and EVP_PKEY_CTX_set_params() 38respectively. 39These functions must only be called after the EVP_PKEY_CTX has been initialised 40for use in an operation. 41 42=head2 Parameters 43 44Examples of EVP_PKEY parameters include the following: 45 46L<provider-keymgmt(7)/Common parameters> 47L<provider-keyexch(7)/Key Exchange parameters> 48L<provider-signature(7)/Signature parameters> 49 50L<EVP_PKEY-RSA(7)/Common RSA parameters> 51L<EVP_PKEY-RSA(7)/RSA key generation parameters> 52L<EVP_PKEY-FFC(7)/FFC parameters> 53L<EVP_PKEY-FFC(7)/FFC key generation parameters> 54L<EVP_PKEY-DSA(7)/DSA parameters> 55L<EVP_PKEY-DSA(7)/DSA key generation parameters> 56L<EVP_PKEY-DH(7)/DH parameters> 57L<EVP_PKEY-DH(7)/DH key generation parameters> 58L<EVP_PKEY-EC(7)/Common EC parameters> 59L<EVP_PKEY-X25519(7)/Common X25519, X448, ED25519 and ED448 parameters> 60L<EVP_PKEY-ML-DSA(7)/Common parameters> 61L<EVP_PKEY-ML-KEM(7)/Common parameters> 62 63=head1 RETURN VALUES 64 65EVP_PKEY_CTX_set_params() returns 1 for success or 0 otherwise. 66EVP_PKEY_CTX_settable_params() returns an OSSL_PARAM array on success or NULL on 67error. 68It may also return NULL if there are no settable parameters available. 69 70All other functions and macros described on this page return a positive value 71for success and 0 or a negative value for failure. In particular a return value 72of -2 indicates the operation is not supported by the public key algorithm. 73 74=head1 SEE ALSO 75 76L<EVP_PKEY_CTX_new(3)>, 77L<EVP_PKEY_encrypt(3)>, 78L<EVP_PKEY_decrypt(3)>, 79L<EVP_PKEY_sign(3)>, 80L<EVP_PKEY_verify(3)>, 81L<EVP_PKEY_verify_recover(3)>, 82L<EVP_PKEY_derive(3)>, 83L<EVP_PKEY_keygen(3)> 84 85=head1 HISTORY 86 87All functions were added in OpenSSL 3.0. 88 89Support for B<ML-DSA>> and B<ML-KEM> was added in OpenSSL 3.5. 90 91=head1 COPYRIGHT 92 93Copyright 2020-2025 The OpenSSL Project Authors. All Rights Reserved. 94 95Licensed under the Apache License 2.0 (the "License"). You may not use 96this file except in compliance with the License. You can obtain a copy 97in the file LICENSE in the source distribution or at 98L<https://www.openssl.org/source/license.html>. 99 100=cut 101