.\" $OpenBSD: radius.3,v 1.1 2015/07/20 23:52:29 yasuoka Exp $
.\"
.\" Copyright (c) 2009 Internet Initiative Japan Inc.
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.Dd $Mdocdate: July 20 2015 $
.Dt NRADIUS 3
.Os
.Sh NAME
.Nm radius
.Nd manipulate RADIUS packets for RADIUS clients/servers
.Sh SYNOPSIS
.In sys/types.h
.In sys/socket.h
.In netinet/in.h
.In stdbool.h
.In radius.h
.Sh DESCRIPTION
.Nm radius
provides a facility to manipulate RADIUS packets and some helper functions.
.Sh CREATING AND DESTROYING PACKETS
RADIUS packet objects are created by
.Fn radius_new_request_packet ,
.Fn radius_new_response_packet
or
.Fn radius_convert_packet .
Authenticator field of the packet that is returned by
.Fn radius_new_request_packet
and
.Fn radius_new_response_packet
is filled with random bytes.
.Pp
You must call
.Fn radius_delete_packet
to free memory associated with the packet object.
.Sh HEADER ACCESSOR
.Fn radius_get_id ,
.Fn radius_get_code ,
.Fn radius_get_authenticator ,
.Fn radius_get_authenticator_retval
and
.Fn radius_get_length
retreives specified property of the packet.
.Fn radius_update_id
update packet's ID field with internal id counter.
.Fn radius_set_id
sets packet's ID field.
.Pp
.Fn radius_set_request_packet
associate request packet to response packet.
Associated request packet can be retrieved by
.Fn radius_get_request_packet .
.Pp
.Fn radius_set_response_authenticator
sets response authenticator to response packet.
.Fn radius_check_response_authenticator
checks response authenticator of response packet.
The request packet must be associated with response packet by
.Fn radius_new_response_packet
or
.Fn radius_set_request_packet .
.Pp
.Fn radius_set_accounting_request_authenticator
sets request authenticator to accounting request packet.
.Fn radius_check_accounting_request_authenticator
checks request authenticator of accounting request packet.
.Pp
.Fn radius_get_request_authenticator_retval
returns authenticator field of the packet if the argument is
a request packet, and returns that of the associated request packet
if the argument is a response packet.
.Pp
.Fn radius_get_data
returns packet data itself.
.Sh RAW ATTRIBUTE ACCESSOR
.Fn radius_get_raw_attr
retrieves attribute value.
.Fa length
is a value-result parameter, initially containing the size of the buffer
and modified on return to indicate the size of the value returned.
If buffer size is not sufficient, returned value is truncated.
.Pp
.Fn radius_put_raw_attr
appends attribute data to the last of the packet.
If buffer size is larger than maximum size of single attribute, this
function returns error.
.Pp
.Fn radius_get_raw_attr_cat
retrieves attrbute value.
Unlike
.Fn radius_get_raw_attr ,
.Fn radius_get_raw_attr_cat
retreives concatenated ALL attrbiute value that have specified attribute type.
If buffer size is not sufficient, this function returns error.
If
.Fa buf
is
.Dv NULL ,
the initial value of
.Fa length
is not cared and the actual size of concatenated values is returned.
.Pp
.Fn radius_put_raw_attr_cat
appends attribute data to the last of the packet.
Unlike
.Fn radius_put_raw_attr ,
.Fn radius_put_raw_attr_cat
divides data into multiple attributes and append them if buffer size is
larger than maximum size of single attribute.
Note that packet object may be broken (but can be deleted normally by
.Fn radius_delete_packet )
if this function have returned error.
.Pp
.Fn radius_get_raw_attr_ptr
retreives pointer and length of specified attribute.
returned buffer must not be modified.
.Pp
.Fn radius_set_raw_attr
overwrite existing attribute value.
If specified attribute does not exist, this function returns error.
If
.Fa length
is different from length of the specified attribute, this function returns error.
.Pp
.Fn radius_del_attr_all
deletes all attributes matching its arguments.
.Pp
.Fn radius_has_attr
returns whether packet has specified attribute.
.Pp
.Fn radius_get_vs_raw_attr ,
.Fn radius_put_vs_raw_attr ,
.Fn radius_get_vs_raw_attr_cat ,
.Fn radius_put_vs_raw_attr_cat ,
.Fn radius_get_vs_raw_attr_ptr ,
.Fn radius_set_vs_raw_attr ,
.Fn radius_del_vs_attr_all
and
.Fn radius_has_vs_attr
are vendor-specific version of raw attribute accessors.
.Sh TYPED ATTRIBUTE ACCESSOR
To make code simple, there are many typed attribute accessors.
.Nm radius
provides typed accessors for
.Li uint16_t ,
.Li uint32_t ,
.Li uint64_t ,
.Li struct in_addr
and
.Li struct in6_addr .
Byte endian may be appropriately swapped for
.Li uint16_t ,
.Li uint32_t
and
.Li uint64_t .
.Pp
These typed accessors do not requires
.Fa length
parameters because length is implied by the type.
For "get" functions, if actual attribute size is different from the size of
the type, the functions return error.
.Pp
There are also typed accessors for string (
.Li char * ).
For "get" function for string, returned string is always NUL-terminated
even if buffer size is smaller than actual attribute size.
This behavior is similar to
.Fn strlcpy .
.Sh MESSAGE AUTHENTICATOR
There exist helper functions for Message-Authenticator attribute.
.Pp
.Fn radius_put_message_authenticator
and
.Fn radius_set_message_authenticator
calculate Message-Authenticator and put or set it to packet, respectively.
.Pp
.Fn radius_check_message_authenticator
checks Message-Authenticator.
.Pp
The request packet must be associated with response packet by
.Fn radius_new_response_packet
or
.Fn radius_set_request_packet ,
otherwise packet is treated as request packet.
.Sh ENCRYPTED ATTRIBUTE
There exist helper functions for encrypted attributes.
.Pp
.Fn radius_encrypt_user_password_attr ,
.Fn radius_decrypt_user_password_attr ,
.Fn radius_encrypt_mppe_key_attr
and
.Fn radius_decrypt_mppe_key_attr
encrypt or decrypt User-Password attribute or MS-MPPE-{Send,Recv}-Key
attributes respectively.
.Pp
.Fn radius_get_user_password_attr ,
.Fn radius_put_user_password_attr ,
.Fn radius_get_mppe_send_key_attr ,
.Fn radius_put_mppe_send_key_attr ,
.Fn radius_get_mppe_recv_key_attr
and
.Fn radius_put_mppe_recv_key_attr
are shortcuts of combination of encrypt/decrypt functions
and get/put functions.
.Sh SENDING AND RECEIVING PACKETS
There exist helper functions to sending and receiving packets.
.Pp
.Fn radius_send ,
.Fn radius_sendto ,
.Fn radius_sendmsg ,
.Fn radius_recv ,
.Fn radius_recvfrom
and
.Fn radius_recvmsg
are helper version of
.Fn send ,
.Fn sendto ,
.Fn sendmsg ,
.Fn recv ,
.Fn recvfrom
and
.Fn recvmsg ,
respectively.
.Pp
.Fn radius_send ,
.Fn radius_sendto
and
.Fn radius_sendmsg
return 0 on success and nonzero on failure.
.Pp
.Fn radius_recv
.Fn radius_recvfrom
and
.Fn radius_recvmsg
return received packet on success and return NULL on failure.
.Pp
Note that
.Li msg_iov
must be
.Li NULL
and
.Li msg_iovlen
must be zero in case of
.Fn radius_sendmsg
and
.Fn radius_recvmsg .
.Sh RETURN VALUES
Functions that return int return 0 on success and nonzero on failure.
Functions that return pointer return non-NULL pointer on success and
NULL on failure.
.\" .Sh SEE ALSO
.Sh HISTORY
.Nm radius+
library is first written by UMEZAWA Takeshi in 2002 for ID gateway service
of Internet Initiative Japan.
YASUOKA Masahiko added support for Message-Authentication attribute in 2008.
OpenBSD project rewrite C++ code to pure C code in 2010.
.Nm radius+
library is renamed
.Nm radius
library and moved to under lib/ in 2013.
.\" .Sh AUTHROS