EVP_PKEY_settable_params(3) | OpenSSL | EVP_PKEY_settable_params(3)

# NAME

EVP_PKEY_settable_params, EVP_PKEY_set_params, EVP_PKEY_set_int_param, EVP_PKEY_set_size_t_param, EVP_PKEY_set_bn_param, EVP_PKEY_set_utf8_string_param, EVP_PKEY_set_octet_string_param - set key parameters into a key

# SYNOPSIS

     #include <openssl/evp.h>
     const OSSL_PARAM *EVP_PKEY_settable_params(const EVP_PKEY *pkey);
     int EVP_PKEY_set_params(EVP_PKEY *pkey, OSSL_PARAM params[]);
     int EVP_PKEY_set_int_param(EVP_PKEY *pkey, const char *key_name, int in);
     int EVP_PKEY_set_size_t_param(EVP_PKEY *pkey, const char *key_name, size_t in);
     int EVP_PKEY_set_bn_param(EVP_PKEY *pkey, const char *key_name,
                               const BIGNUM *bn);
     int EVP_PKEY_set_utf8_string_param(EVP_PKEY *pkey, const char *key_name,
                                        const char *str);
     int EVP_PKEY_set_octet_string_param(EVP_PKEY *pkey, const char *key_name,
                                         const unsigned char *buf, size_t bsize);

# DESCRIPTION

These functions can be used to set additional parameters into an existing EVP_PKEY.

EVP_PKEY_set_params() sets one or more params into a pkey. See OSSL_PARAM(3) for information about parameters.

EVP_PKEY_settable_params() returns a constant list of params indicating the names and types of key parameters that can be set. See OSSL_PARAM(3) for information about parameters.

EVP_PKEY_set_int_param() sets an integer value in into a key pkey for the associated field key_name.

EVP_PKEY_set_size_t_param() sets an size_t value in into a key pkey for the associated field key_name.

EVP_PKEY_set_bn_param() sets the BIGNUM value bn into a key pkey for the associated field key_name.

EVP_PKEY_set_utf8_string_param() sets the UTF8 string str into a key pkey for the associated field key_name.

EVP_PKEY_set_octet_string_param() sets the octet string value buf with a size bsize into a key pkey for the associated field key_name.

# NOTES

These functions only work for EVP_PKEYs that contain a provider side key.

# RETURN VALUES

EVP_PKEY_settable_params() returns NULL on error or if it is not supported,

All other methods return 1 if a value was successfully set, or 0 if there was an error.

# SEE ALSO

EVP_PKEY_gettable_params(3), EVP_PKEY_CTX_new(3), provider-keymgmt(7), OSSL_PARAM(3),

# HISTORY

These functions were added in OpenSSL 3.0.

# COPYRIGHT

Copyright 2020-2021 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>.

2026-06-09 | 3.5.7