Add description of SSL_[CTX_]_check_private_key().

=head1 NAME

SSL_CTX_use_certificate, SSL_CTX_use_certificate_ASN1, SSL_CTX_use_certificate_file, SSL_use_certificate, SSL_use_certificate_ASN1, SSL_use_certificate_file, SSL_CTX_use_certificate_chain_file, SSL_CTX_use_PrivateKey, SSL_CTX_use_PrivateKey_ASN1, SSL_CTX_use_PrivateKey_file, SSL_CTX_use_RSAPrivateKey, SSL_CTX_use_RSAPrivateKey_ASN1, SSL_CTX_use_RSAPrivateKey_file, SSL_use_PrivateKey_file, SSL_use_PrivateKey_ASN1, SSL_use_PrivateKey, SSL_use_RSAPrivateKey, SSL_use_RSAPrivateKey_ASN1, SSL_use_RSAPrivateKey_file - load certificate and key data

SSL_CTX_use_certificate, SSL_CTX_use_certificate_ASN1, SSL_CTX_use_certificate_file, SSL_use_certificate, SSL_use_certificate_ASN1, SSL_use_certificate_file, SSL_CTX_use_certificate_chain_file, SSL_CTX_use_PrivateKey, SSL_CTX_use_PrivateKey_ASN1, SSL_CTX_use_PrivateKey_file, SSL_CTX_use_RSAPrivateKey, SSL_CTX_use_RSAPrivateKey_ASN1, SSL_CTX_use_RSAPrivateKey_file, SSL_use_PrivateKey_file, SSL_use_PrivateKey_ASN1, SSL_use_PrivateKey, SSL_use_RSAPrivateKey, SSL_use_RSAPrivateKey_ASN1, SSL_use_RSAPrivateKey_file, SSL_CTX_check_private_key, SSL_check_private_key- load certificate and key data

=head1 SYNOPSIS

 int SSL_use_RSAPrivateKey_ASN1(SSL *ssl, unsigned char *d, long len);

 int SSL_use_RSAPrivateKey_file(SSL *ssl, const char *file, int type);

 int SSL_CTX_check_private_key(SSL_CTX *ctx);

 int SSL_check_private_key(SSL *ssl);

=head1 DESCRIPTION

These functions load the certificates and private keys into the SSL_CTX

in B<file> to B<ssl>; SSL_use_RSAPrivateKey_file() adds the first private

RSA key found to B<ssl>.

SSL_CTX_check_private_key() checks the consistency of a private key with

the corresponding certificate loaded into B<ctx>. If more than one

key/certificate pair (RSA/DSA) is installed, the last item installed will

be checked. If e.g. the last item was a RSA certificate or key, the RSA

key/certificate pair will be checked. SSL_check_private_key() performs

the same check for B<ssl>. If no key/certificate was explicitly added for

this B<ssl>, the last item added into B<ctx> will be checked.

=head1 NOTES

The internal certificate store of OpenSSL can hold two private key/certificate