summaryrefslogtreecommitdiffstats
path: root/lib/libradius/libradius.3
blob: 3ccd9e4275b2a1a35d21b1d0db395696c71e901c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
.\" Copyright 1998 Juniper Networks, 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.
.\"
.\" $FreeBSD$
.\"
.Dd October 30, 1999
.Dt LIBRADIUS 3
.Os
.Sh NAME
.Nm libradius
.Nd RADIUS client library
.Sh SYNOPSIS
.In radlib.h
.Ft struct rad_handle *
.Fn rad_acct_open "void"
.Ft int
.Fn rad_add_server "struct rad_handle *h" "const char *host" "int port" "const char *secret" "int timeout" "int max_tries"
.Ft struct rad_handle *
.Fn rad_auth_open "void"
.Ft void
.Fn rad_close "struct rad_handle *h"
.Ft int
.Fn rad_config "struct rad_handle *h" "const char *file"
.Ft int
.Fn rad_continue_send_request "struct rad_handle *h" "int selected" "int *fd" "struct timeval *tv"
.Ft int
.Fn rad_create_request "struct rad_handle *h" "int code"
.Ft struct in_addr
.Fn rad_cvt_addr "const void *data"
.Ft u_int32_t
.Fn rad_cvt_int "const void *data"
.Ft char *
.Fn rad_cvt_string "const void *data" "size_t len"
.Ft int
.Fn rad_get_attr "struct rad_handle *h" "const void **data" "size_t *len"
.Ft int
.Fn rad_get_vendor_attr "u_int32_t *vendor" "const void **data" "size_t *len"
.Ft int
.Fn rad_init_send_request "struct rad_handle *h" "int *fd" "struct timeval *tv"
.Ft int
.Fn rad_put_addr "struct rad_handle *h" "int type" "struct in_addr addr"
.Ft int
.Fn rad_put_attr "struct rad_handle *h" "int type" "const void *data" "size_t len"
.Ft int
.Fn rad_put_int "struct rad_handle *h" "int type" "u_int32_t value"
.Ft int
.Fn rad_put_string "struct rad_handle *h" "int type" "const char *str"
.Ft int
.Fn rad_put_vendor_addr "struct rad_handle *h" "int vendor" "int type" "struct in_addr addr"
.Ft int
.Fn rad_put_vendor_attr "struct rad_handle *h" "int vendor" "int type" "const void *data" "size_t len"
.Ft int
.Fn rad_put_vendor_int "struct rad_handle *h" "int vendor" "int type" "u_int32_t value"
.Ft int
.Fn rad_put_vendor_string "struct rad_handle *h" "int vendor" "int type" "const char *str"
.Ft int
.Fn rad_send_request "struct rad_handle *h"
.Ft const char *
.Fn rad_strerror "struct rad_handle *h"
.Sh DESCRIPTION
The
.Nm
library implements the client side of the Remote Authentication Dial
In User Service (RADIUS).  RADIUS, defined in RFCs 2138 and 2139,
allows clients to perform authentication and accounting by means of
network requests to remote servers.
.Sh INITIALIZATION
To use the library, an application must first call
.Fn rad_auth_open
or
.Fn rad_acct_open
to obtain a
.Va struct rad_handle * ,
which provides the context for subsequent operations.
The former function is used for RADIUS authentication and the
latter is used for RADIUS accounting.
Calls to
.Fn rad_auth_open
and
.Fn rad_acct_open
always succeed unless insufficient virtual memory is available.  If
the necessary memory cannot be allocated, the functions return
.Dv NULL .
For compatibility with earlier versions of this library,
.Fn rad_open
is provided as a synonym for
.Fn rad_auth_open .
.Pp
Before issuing any RADIUS requests, the library must be made aware
of the servers it can contact.  The easiest way to configure the
library is to call
.Fn rad_config .
.Fn rad_config
causes the library to read a configuration file whose format is
described in
.Xr radius.conf 5 .
The pathname of the configuration file is passed as the
.Va file
argument to
.Fn rad_config .
This argument may also be given as
.Dv NULL ,
in which case the standard configuration file
.Pa /etc/radius.conf
is used.
.Fn rad_config
returns 0 on success, or -1 if an error occurs.
.Pp
The library can also be configured programmatically by calls to
.Fn rad_add_server .
The
.Va host
parameter specifies the server host, either as a fully qualified
domain name or as a dotted-quad IP address in text form.
The
.Va port
parameter specifies the UDP port to contact on the server.  If
.Va port
is given as 0, the library looks up the
.Ql radius/udp
or
.Ql radacct/udp
service in the network services database, and uses the port found
there.  If no entry is found, the library uses the standard RADIUS
ports, 1812 for authentication and 1813 for accounting.
The shared secret for the server host is passed to the
.Va secret
parameter.
It may be any NUL-terminated string of bytes.  The RADIUS protocol
ignores all but the leading 128 bytes of the shared secret.
The timeout for receiving replies from the server is passed to the
.Va timeout
parameter, in units of seconds.  The maximum number of repeated
requests to make before giving up is passed into the
.Va max_tries
parameter.
.Fn rad_add_server
returns 0 on success, or -1 if an error occurs.
.Pp
.Fn rad_add_server
may be called multiple times, and it may be used together with
.Fn rad_config .
At most 10 servers may be specified.
When multiple servers are given, they are tried in round-robin
fashion until a valid response is received, or until each server's
.Va max_tries
limit has been reached.
.Sh CREATING A RADIUS REQUEST
A RADIUS request consists of a code specifying the kind of request,
and zero or more attributes which provide additional information.  To
begin constructing a new request, call
.Fn rad_create_request .
In addition to the usual
.Va struct rad_handle * ,
this function takes a
.Va code
parameter which specifies the type of the request.  Most often this
will be
.Dv RAD_ACCESS_REQUEST .
.Fn rad_create_request
returns 0 on success, or -1 on if an error occurs.
.Pp
After the request has been created with
.Fn rad_create_request ,
attributes can be attached to it.  This is done through calls to
.Fn rad_put_addr ,
.Fn rad_put_int ,
and
.Fn rad_put_string .
Each accepts a
.Va type
parameter identifying the attribute, and a value which may be
an Internet address, an integer, or a NUL-terminated string,
respectively.
Alternatively,
.Fn rad_put_vendor_addr ,
.Fn rad_put_vendor_int
or
.Fn rad_put_vendor_string
may be used to specify vendor specific attributes.  Vendor specific
definitions may be found in
.In radlib_vs.h
.Pp
The library also provides a function
.Fn rad_put_attr
which can be used to supply a raw, uninterpreted attribute.  The
.Va data
argument points to an array of bytes, and the
.Va len
argument specifies its length.
.Pp
The
.Fn rad_put_X
functions return 0 on success, or -1 if an error occurs.
.Sh SENDING THE REQUEST AND RECEIVING THE RESPONSE
After the RADIUS request has been constructed, it is sent either by means of
.Fn rad_send_request
or by a combination of calls to
.Fn rad_init_send_request
and
.Fn rad_continue_send_request .
.Pp
The
.Fn rad_send_request
function sends the request and waits for a valid reply,
retrying the defined servers in round-robin fashion as necessary.
If a valid response is received,
.Fn rad_send_request
returns the RADIUS code which specifies the type of the response.
This will typically be
.Dv RAD_ACCESS_ACCEPT ,
.Dv RAD_ACCESS_REJECT ,
or
.Dv RAD_ACCESS_CHALLENGE .
If no valid response is received,
.Fn rad_send_request
returns -1.
.Pp
As an alternative, if you do not wish to block waiting for a response,
.Fn rad_init_send_request
and
.Fn rad_continue_send_request
may be used instead.  If a reply is received from the RADIUS server or a
timeout occurs, these functions return a value as described for
.Fn rad_send_request .
Otherwise, a value of zero is returned and the values pointed to by
.Ar fd
and
.Ar tv
are set to the descriptor and timeout that should be passed to
.Xr select 2 .
.Pp
.Fn rad_init_send_request
must be called first, followed by repeated calls to
.Fn rad_continue_send_request
as long as a return value of zero is given.
Between each call, the application should call
.Xr select 2 ,
passing
.Ar *fd
as a read descriptor and timing out after the interval specified by
.Ar tv .
When select returns,
.Fn rad_continue_send_request
should be called with
.Ar selected
set to a non-zero value if
.Xr select 2
indicated that the descriptor is readable.
.Pp
Like RADIUS requests, each response may contain zero or more
attributes.  After a response has been received successfully by
.Fn rad_send_request
or
.Fn rad_continue_send_request ,
its attributes can be extracted one by one using
.Fn rad_get_attr .
Each time
.Fn rad_get_attr
is called, it gets the next attribute from the current response, and
stores a pointer to the data and the length of the data via the
reference parameters
.Va data
and
.Va len ,
respectively.  Note that the data resides in the response itself,
and must not be modified.
A successful call to
.Fn rad_get_attr
returns the RADIUS attribute type.
If no more attributes remain in the current response,
.Fn rad_get_attr
returns 0.
If an error such as a malformed attribute is detected, -1 is
returned.
.Pp
If
.Fn rad_get_attr
returns
.Dv RAD_VENDOR_SPECIFIC ,
.Fn rad_get_vendor_attr
may be called to determine the vendor.
The vendor specific RADIUS attribute type is returned.
The reference parameters
.Va data
and
.Va len
.Pq as returned from Fn rad_get_attr
are passed to
.Fn rad_get_vendor_attr ,
and are adjusted to point to the vendor specific attribute data.
.Pp
The common types of attributes can be decoded using
.Fn rad_cvt_addr ,
.Fn rad_cvt_int ,
and
.Fn rad_cvt_string .
These functions accept a pointer to the attribute data, which should
have been obtained using
.Fn rad_get_attr
and optionally
.Fn rad_get_vendor_attr .
In the case of
.Fn rad_cvt_string ,
the length
.Va len
must also be given.  These functions interpret the attribute as an
Internet address, an integer, or a string, respectively, and return
its value.
.Fn rad_cvt_string
returns its value as a NUL-terminated string in dynamically
allocated memory.  The application should free the string using
.Xr free 3
when it is no longer needed.
.Pp
If insufficient virtual memory is available,
.Fn rad_cvt_string
returns
.Dv NULL .
.Fn rad_cvt_addr
and
.Fn rad_cvt_int
cannot fail.
.Sh OBTAINING ERROR MESSAGES
Those functions which accept a
.Va struct rad_handle *
argument record an error message if they fail.  The error message
can be retrieved by calling
.Fn rad_strerror .
The message text is overwritten on each new error for the given
.Va struct rad_handle * .
Thus the message must be copied if it is to be preserved through
subsequent library calls using the same handle.
.Sh CLEANUP
To free the resources used by the RADIUS library, call
.Fn rad_close .
.Sh RETURN VALUES
The following functions return a non-negative value on success.  If
they detect an error, they return -1 and record an error message
which can be retrieved using
.Fn rad_strerror .
.Pp
.Bl -item -offset indent -compact
.It
.Fn rad_add_server
.It
.Fn rad_config
.It
.Fn rad_create_request
.It
.Fn rad_get_attr
.It
.Fn rad_put_addr
.It
.Fn rad_put_attr
.It
.Fn rad_put_int
.It
.Fn rad_put_string
.It
.Fn rad_init_send_request
.It
.Fn rad_continue_send_request
.It
.Fn rad_send_request
.El
.Pp
The following functions return a
.No non- Ns Dv NULL
pointer on success.  If they are unable to allocate sufficient
virtual memory, they return
.Dv NULL ,
without recording an error message.
.Pp
.Bl -item -offset indent -compact
.It
.Fn rad_acct_open
.It
.Fn rad_auth_open
.It
.Fn rad_cvt_string
.El
.Sh FILES
.Pa /etc/radius.conf
.Sh SEE ALSO
.Xr radius.conf 5
.Rs
.%A C. Rigney, et al
.%T "Remote Authentication Dial In User Service (RADIUS)"
.%O RFC 2138
.Re
.Rs
.%A C. Rigney
.%T RADIUS Accounting
.%O RFC 2139
.Re
.Sh AUTHORS
This software was originally written by
.An John Polstra ,
and donated to the
.Fx
project by Juniper Networks, Inc.
Oleg Semyonov subsequently added the ability to perform RADIUS
accounting.
OpenPOWER on IntegriCloud