Update EVP_PKEY documentation.

=head1 NAME

EVP_PKEY_new, EVP_PKEY_free - private key allocation functions.

EVP_PKEY_new, EVP_PKEY_up_ref, EVP_PKEY_free - private key allocation functions.

=head1 SYNOPSIS

 #include <openssl/evp.h>

 EVP_PKEY *EVP_PKEY_new(void);

 void EVP_PKEY_up_ref(EVP_PKEY *key);

 void EVP_PKEY_free(EVP_PKEY *key);

=head1 DESCRIPTION

The EVP_PKEY_new() function allocates an empty B<EVP_PKEY> 

structure which is used by OpenSSL to store private keys.

The EVP_PKEY_new() function allocates an empty B<EVP_PKEY> structure which is

used by OpenSSL to store private keys. The reference count is set to B<1>.

EVP_PKEY_free() frees up the private key B<key>.

If B<key> is NULL, nothing is done.

EVP_PKEY_up_ref() increments the reference count of B<key>.

EVP_PKEY_free() decrements the reference count of B<key> and, if the reference

count is zero, frees it up. If B<key> is NULL, nothing is done.

=head1 NOTES

The B<EVP_PKEY> structure is used by various OpenSSL functions

which require a general private key without reference to any

particular algorithm.

The B<EVP_PKEY> structure is used by various OpenSSL functions which require a

general private key without reference to any particular algorithm.

The structure returned by EVP_PKEY_new() is empty. To add a

private key to this empty structure the functions described in

L<EVP_PKEY_set1_RSA(3)> should be used.

The structure returned by EVP_PKEY_new() is empty. To add a private key to this

empty structure the functions described in L<EVP_PKEY_set1_RSA(3)> should be

used.

=head1 RETURN VALUES

EVP_PKEY_new() returns either the newly allocated B<EVP_PKEY>

structure of B<NULL> if an error occurred.

EVP_PKEY_new() returns either the newly allocated B<EVP_PKEY> structure or

B<NULL> if an error occurred.

EVP_PKEY_free() does not return a value.

EVP_PKEY_up_ref() and EVP_PKEY_free() do not return a value.

=head1 SEE ALSO

=head1 HISTORY

TBA

EVP_PKEY_new() and EVP_PKEY_free() exist in all versions of OpenSSL.

EVP_PKEY_up_ref() was first added to OpenSSL 1.1.0.

=cut