BIO_hostserv_priorities, BIO_parse_hostserv - utility routines to parse a standard host and service string

#include <openssl/bio.h>

enum BIO_hostserv_priorities {
int BIO_parse_hostserv(const char *hostserv, char **host, char **service,
                       enum BIO_hostserv_priorities hostserv_prio);

BIO_parse_hostserv() will parse the information given in hostserv, create strings with the hostname and service name and give those back via host and service. Those will need to be freed after they are used. hostserv_prio helps determine if hostserv shall be interpreted primarily as a hostname or a service name in ambiguous cases.

The syntax the BIO_parse_hostserv() recognises is:

host + ':' + service
host + ':' + '*'
host + ':'
       ':' + service
'*'  + ':' + service

The host part can be a name or an IP address. If it's a IPv6 address, it MUST be enclosed in brackets, such as '[::1]'.

The service part can be a service name or its port number.

The returned values will depend on the given hostserv string and hostserv_prio, as follows:

host + ':' + service  => *host = "host", *service = "service"
host + ':' + '*'      => *host = "host", *service = NULL
host + ':'            => *host = "host", *service = NULL
       ':' + service  => *host = NULL, *service = "service"
 '*' + ':' + service  => *host = NULL, *service = "service"

in case no ':' is present in the string, the result depends on
hostserv_prio, as follows:

when hostserv_prio == BIO_PARSE_PRIO_HOST
host                 => *host = "host", *service untouched

when hostserv_prio == BIO_PARSE_PRIO_SERV
service              => *host untouched, *service = "service"

BIO_parse_hostserv() returns 1 on success or 0 on error.


Copyright 2016-2020 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

2021-02-17 1.1.1j