EVP_PKEY_CTX_set_params.3ossl - Man Page

provider parameter passing operations


 #include <openssl/evp.h>

 int EVP_PKEY_CTX_set_params(EVP_PKEY_CTX *ctx, const OSSL_PARAM *params);
 const OSSL_PARAM *EVP_PKEY_CTX_settable_params(const EVP_PKEY_CTX *ctx);
 int EVP_PKEY_CTX_get_params(EVP_PKEY_CTX *ctx, OSSL_PARAM *params);
 const OSSL_PARAM *EVP_PKEY_CTX_gettable_params(const EVP_PKEY_CTX *ctx);


The EVP_PKEY_CTX_get_params() and EVP_PKEY_CTX_set_params() functions allow transfer of arbitrary key parameters to and from providers. Not all parameters may be supported by all providers. See OSSL_PROVIDER(3) for more information on providers. See OSSL_PARAM(3) for more information on parameters. These functions must only be called after the EVP_PKEY_CTX has been initialised for use in an operation. These methods replace the EVP_PKEY_CTX_ctrl() mechanism. (EVP_PKEY_CTX_ctrl now calls these methods internally to interact with providers).

EVP_PKEY_CTX_gettable_params() and EVP_PKEY_CTX_settable_params() get a constant OSSL_PARAM array that describes the gettable and settable parameters for the current algorithm implementation, i.e. parameters that can be used with EVP_PKEY_CTX_get_params() and EVP_PKEY_CTX_set_params() respectively. See OSSL_PARAM(3) for the use of OSSL_PARAM as parameter descriptor. These functions must only be called after the EVP_PKEY_CTX has been initialised for use in an operation.


Examples of EVP_PKEY parameters include the following:

“Common parameters” in provider-keymgmt(7) “Key Exchange parameters” in provider-keyexch(7) “Signature parameters” in provider-signature(7)

“Common RSA parameters” in EVP_PKEY-RSA(7) “RSA key generation parameters” in EVP_PKEY-RSA(7) “FFC parameters” in EVP_PKEY-FFC(7) “FFC key generation parameters” in EVP_PKEY-FFC(7) “DSA parameters” in EVP_PKEY-DSA(7) “DSA key generation parameters” in EVP_PKEY-DSA(7) “DH parameters” in EVP_PKEY-DH(7) “DH key generation parameters” in EVP_PKEY-DH(7) “Common EC parameters” in EVP_PKEY-EC(7) “Common X25519, X448, ED25519 and ED448 parameters” in EVP_PKEY-X25519(7)

Return Values

EVP_PKEY_CTX_set_params() returns 1 for success or 0 otherwise. EVP_PKEY_CTX_settable_params() returns an OSSL_PARAM array on success or NULL on error. It may also return NULL if there are no settable parameters available.

All other functions and macros described on this page return a positive value for success and 0 or a negative value for failure. In particular a return value of -2 indicates the operation is not supported by the public key algorithm.

See Also

EVP_PKEY_CTX_new(3), EVP_PKEY_encrypt(3), EVP_PKEY_decrypt(3), EVP_PKEY_sign(3), EVP_PKEY_verify(3), EVP_PKEY_verify_recover(3), EVP_PKEY_derive(3), EVP_PKEY_keygen(3)


All functions were added in OpenSSL 3.0.

Referenced By

EVP_ASYM_CIPHER_free.3ossl(3), EVP_KEM_free.3ossl(3), EVP_KEYEXCH_free.3ossl(3), EVP_KEYMGMT.3ossl(3), EVP_PKEY_CTX_ctrl.3ossl(3), EVP_PKEY_decapsulate.3ossl(3), EVP_PKEY_encapsulate.3ossl(3), EVP_PKEY_keygen.3ossl(3), EVP_SIGNATURE-DSA.7ossl(7), EVP_SIGNATURE-ECDSA.7ossl(7), EVP_SIGNATURE_free.3ossl(3), EVP_SIGNATURE-RSA.7ossl(7).

The man pages EVP_PKEY_CTX_get_params.3ossl(3), EVP_PKEY_CTX_gettable_params.3ossl(3) and EVP_PKEY_CTX_settable_params.3ossl(3) are aliases of EVP_PKEY_CTX_set_params.3ossl(3).

2021-09-09 3.0.0 OpenSSL