/usr/man/cat.3/X509_check_private_key.3

X509_check_private_key(3)    OpenSSL    X509_check_private_key(3)

NAME

     X509_check_private_key, X509_REQ_check_private_key - check
     the consistency of a private key with the public key in an
     X509 certificate or certificate request

SYNOPSIS

      #include <openssl/x509.h>

      int X509_check_private_key(X509 *x, EVP_PKEY *k);

      int X509_REQ_check_private_key(X509_REQ *x, EVP_PKEY *k);

DESCRIPTION

     X509_check_private_key() function checks the consistency of
     private key k with the public key in x.

     X509_REQ_check_private_key() is equivalent to
     X509_check_private_key() except that x represents a
     certificate request of structure X509_REQ.

RETURN VALUE

     X509_check_private_key() and X509_REQ_check_private_key()
     return 1 if the keys match each other, and 0 if not.

     If the key is invalid or an error occurred, the reason code
     can be obtained using ERR_get_error(3).

BUGS

     The check_private_key functions don't check if k itself is
     indeed a private key or not. It merely compares the public
     materials (e.g. exponent and modulus of an RSA key) and/or
     key parameters (e.g. EC params of an EC key) of a key pair.
     So if you pass a public key to these functions in k, it will
     return success.

SEE ALSO

     ERR_get_error(3)

COPYRIGHT

     Copyright 2017 The OpenSSL Project Authors. All Rights
     Reserved.

     Licensed under the OpenSSL license (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>.

1.0.2t               Last change: 2019-09-10                    1

See also X509_REQ_check_private_key(3)