Updated: 2022/Sep/29

Please read Privacy Policy. It's for your privacy.

EVP_PKEY_todata(3)                  OpenSSL                 EVP_PKEY_todata(3)



NAME
       EVP_PKEY_todata, EVP_PKEY_export - functions to return keys as an array
       of key parameters

LIBRARY
       libcrypto, -lcrypto

SYNOPSIS
        #include <openssl/evp.h>

        int EVP_PKEY_todata(const EVP_PKEY *pkey, int selection, OSSL_PARAM **params);
        int EVP_PKEY_export(const EVP_PKEY *pkey, int selection,
                            OSSL_CALLBACK *export_cb, void *export_cbarg);

DESCRIPTION
       The functions described here are used to extract EVP_PKEY key values as
       an array of OSSL_PARAM(3).

       EVP_PKEY_todata() extracts values from a key pkey using the selection.
       selection is described in "Selections" in EVP_PKEY_fromdata(3).
       OSSL_PARAM_free(3) should be used to free the returned parameters in
       *params.

       EVP_PKEY_export() is similar to EVP_PKEY_todata() but uses a callback
       export_cb that gets passed the value of export_cbarg.  See
       openssl-core.h(7) for more information about the callback. Note that
       the OSSL_PARAM(3) array that is passed to the callback is not
       persistent after the callback returns. The user must preserve the items
       of interest, or use EVP_PKEY_todata() if persistence is required.

NOTES
       These functions only work with key management methods coming from a
       provider.  This is the mirror function to EVP_PKEY_fromdata(3).

RETURN VALUES
       EVP_PKEY_todata() and EVP_PKEY_export() return 1 for success and 0 for
       failure.

SEE ALSO
       OSSL_PARAM(3), openssl-core.h(7), EVP_PKEY_fromdata(3),
       EVP_PKEY-RSA(7), EVP_PKEY-DSA(7), EVP_PKEY-DH(7), EVP_PKEY-EC(7),
       EVP_PKEY-ED448(7), EVP_PKEY-X25519(7), EVP_PKEY-X448(7),
       EVP_PKEY-ED25519(7)

HISTORY
       These functions were added in OpenSSL 3.0.

COPYRIGHT
       Copyright 2021-2023 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>.



3.0.12                            2023-10-25                EVP_PKEY_todata(3)