added subjectaltname cert checks, incl regexp uri

[radsecproxy.git] / radsecproxy.conf.5

.TH radsecproxy.conf 5 "13 June 2007"

.SH "NAME"
radsecproxy.conf - Radsec proxy configuration file

.SH "DESCRIPTION"

When the proxy server starts, it will first check the command line arguments,
and then read the configuration file. If specified by the command line -c option
(read \fIradsecproxy(1)\fR for details), the specified file is tried first and
if that fails the file of the same name in current directory is tried.
.sp
If -c option isn't used the proxy will read the file 
\fB/etc/radsecproxy.conf\fR. If that fails server will look for
\fBradsecproxy.conf\fR in the \fBcurrent directory\fR.
.sp
If the configuration file can not be found, the proxy will exit with an error
message.

.SH "CONFIGURATION SYNTAX"
When the configuration file is processed, whitespace (spaces and tabs) are
generally ignored. For each line, leading and trailing whitespace are ignored.
A line is ignored if it is empty, only consists of whitespace, or if the first 
non-whitespace character is a \fB#\fR. The configuration is generally case 
insensitive, but in some cases the option values (see below) are not.
.sp
There are two types of configuration structures than can be used. The first
and simplest are lines of the format \fIoption value\fR. That is, an option name,
see below for a list of valid options, followed by whitespace (at least one
space or tab character), followed by a value. Note that if the value contains
whitespace, then it must be quoted using "" or ''. Any whitespace in front of
the option or after the value will be ignored.
.sp
The other type of structure is a block. A block spans at least two lines, and
has the format:
.sp
.IP
.nf
blocktype name {
    option value
    option value
    ...
}
.fi
.LP
That is, some blocktype, see below for a list of the different block types, and
then enclosed in braces you have zero or more lines that each have the previously
described \fIoption value\fR format. Different block types have different rules for
which options can be specified, they are listed below. The rules regarding white
space, comments and quotes are as above. Hence you may do things like:
.sp
.IP
.nf
blocktype name {
#    option value
    option "value with space"
    ...
}
.fi
.LP

.SH "BASIC OPTIONS"
The following basic options may be specified in the configuration file. Note that
blocktypes and options inside blocks are discussed later. Note that none of these
options are required, and indeed in many cases they are not needed. Note that you
should specify each at most once. The behaviour with multiple occurences is
undefined.
.sp
.TP
\fBLogLevel\fR
This option specifies the debug level. It must be set to 1, 2, 3 or 4, where 1
logs only serious errors, and 4 logs \fIeverything\fR. The default is 3 which logs
errors, warnings and some informational messages. Note that the command line option
\fB-d\fR overrides this if present.
.sp
.TP
\fBLogDestination\fR
This specifies where the log messages should go. By default the messages go to
syslog with facility \fBLOG_DAEMON\fR. Using this option you can specify another
syslog facility, or you may specify that logging should be to a particular file,
not using syslog. The value must be either a \fIfile\fR or \fIsyslog\fR URL. The
file URL is the standard one, specifying a local file that should be used. For
syslog, you must use the syntax: \fBx-syslog:///FACILITY\fR where
\fBFACILITY\fR must be one of \fBLOG_DAEMON\fR, \fBLOG_MAIL\fR, \fBLOG_USER\fR,
\fBLOG_LOCAL0\fR, \fBLOG_LOCAL1\fR, \fBLOG_LOCAL2\fR, \fBLOG_LOCAL3\fR,
\fBLOG_LOCAL4\fR, \fBLOG_LOCAL5\fR, \fBLOG_LOCAL6\fR or \fBLOG_LOCAL7\fR. You may
omit the facility from the URL to specify logging to the default facility, but
this is not very useful since this is the default log destination. Note that this
option is ignored if \fB-f\fR is specified on the command line.
.sp
.TP
\fBListenUDP\fR
Normally the proxy will listen to the standard RADIUS UDP port \fB1812\fR if
configured to handle UDP clients. On most systems it will do this for all of the
system's IP addresses (both IPv4 and IPv6). On some systems however, it may respond
to only IPv4 or only IPv6. To specify an alternate port you may use a value of
the form \fB*:port\fR where port is any valid port number. If you also want to
specify a specific address you can do e.g. \fB192.168.1.1:1812\fR or
\fB[2001:db8::1]:1812\fR. The port may be omitted if you want the default one
(like in these examples). These examples are equivalent to \fB192.168.1.1\fR and
\fB2001:db8::1\fR. Note that you must use brackets around the IPv6 address if
you specify port number.
.sp
.TP
\fBListenTCP\fR
This is similar to the \fBListenUDP\fR option, except that it used for receiving
connections from TCP clients. The default port number is \fB2083\fR.
.sp

.SH "BLOCKS"
There are four types of blocks, they are \fBClient\fR, \fBServer\fR, \fBRealm\fR
and \fBTLS\fR. At least one instance of each of \fBClient\fR, \fBServer\fR and
\fBRealm\fR is required. This is necessary for the proxy to do anything useful,
and it will exit if not. The \fBTLS\fR block is required if at least one TLS
client or server is configured. Note that there can be multiple blocks for each
type. For each type, the block names should be unique. The behaviour with multiple
occurences of the same name for the same block type is undefined. Also note that
some block option values may reference a block by name, in which case the block
name must be previously defined. Hence the order of the blocks may be significant.
.sp

.SH "CLIENT BLOCK"
The client block is used to configure a client. That is, tell the proxy about a
client, and what parameters should be used for that client. The \fBname\fR of the
client block must be either the IP address (IPv4 or IPv6) of the client, or a
domain name (FQDN). If a domain name is specified, then this will be resolved
immediately to all the addresses associated with the name, and the proxy will not
care about any possible DNS changes that might occur later. Hence there is no
dependency on DNS after startup. When some client later sends a request to the
proxy, the proxy will look at the IP address the request comes from, and then go
through all the addresses of each of the configured clients, to determine which
(if any) of the clients this is. In the case of TLS, the name of the client must
match the FQDN or IP address in the client certificate. Note that at the time of
writing it must match the certificate CN. This will be extended to check
subjectAltName if present.
.sp
The allowed options in a client block are \fBtype\fR, \fBsecret\fR and \fBtls\fR.
The value of \fBtype\fR must be either \fBudp\fR or \fBtls\fR. The value of
\fBsecret\fR is the shared RADIUS key used with this client. If the secret
contains whitespace, the value must be quoted. This option is optional for TLS.
For a TLS client you may also specify the \fBtls\fR option. The option value must
be the name of a previously defined TLS block. If this option is not specified,
the TLS block with the name \fBdefaultclient\fR will be used if defined. If not
defined, it will try to use the TLS block named \fBdefault\fR. If the specified
TLS block name does not exist, or the option is not specified and none of the
defaults exist, the proxy will exit with an error.
.sp

.SH "SERVER BLOCK"
The server block is used to configure a server. That is, tell the proxy about
a server, and what parameters should be used when communicating with that server.
The \fBname\fR of the server block must be either the IP address (IPv4 or IPv6)
of the server, or a domain name (FQDN). If a domain name is specified, then this
will be resolved immediately to all the addresses associated with the name, and
the proxy will not care about any possible DNS changes that might occur later.
Hence there is no dependency on DNS after startup. If the domain name resolves
to multiple addresses, then for UDP the first address is used. For TLS, the proxy
will loop through the addresses until it can connect to one of them. In the case
of TLS, the name of the server must match the FQDN or IP address in the server
certificate. Note that at the time of writing it must match the certificate CN.
This will be extended to check subjectAltName if present.
.sp
The allowed options in a server block are \fBtype\fR, \fBsecret\fR, \fBtls\fR,
\fBport\fR and \fBstatusServer\fR. The values of \fBtype\fR, \fBsecret\fR and
\fBtls\fR are just as specified for the \fIclient block\fR above, except that
\fBdefaultserve\fRr (and not \fBdefaultclient\fR) is used as a fallback if the
\fBtls\fR option is not used.
.sp
The \fBport\fR option allows you to specify which port number the server uses.
\fBstatusServer\fR can be specified to enable the use of statusServer messages
for this server. The value must be either \fBon\fR or \fBoff\fR. The default
when not specified, is \fBoff\fR. If statusServer is enabled, the proxy will
during idle periods send regular statusServer messages to the server to verify
that it is alive. This should only be enabled if the server supports it.

.SH "REALM BLOCK"
When the proxy receives an \fBAccess Request\fR it needs to figure out to which
server it should be forwarded. This is done by looking at the Username attribute
in the request, and matching that against the names of the defined realm blocks.
The proxy will match against the blocks in the order they are specified, using
the first match if any. If no realm matches, the proxy will simply ignore the
request. Each realm block specifies what the server should do when a match is
found. A realm block may contain at most one \fBserver\fR option, and at most
one \fBreplyMessage\fR option. We will discuss these later.
.sp

.TP
\fBRealm block names and matching\fR
.sp
In the general case the proxy will look for a @ in the username attribute, and
try to do an exact case insensitive match between what comes after the @ and
the name of the realm block. So if you get a request with the attribute value
\fBanonymous@example.com\fR, the proxy will go through the realm names in the
order they are specified, looking for a realm block named \fBexample.com\fR.
.sp
There are two exceptions to this, one is the realm name \fB*\fT which means
match everything. Hence if you have a realm block named \fB*\fR, then it will
always match. This should then be the last realm block defined, since any
blocks after this would never be checked. This is useful for having a default.
.sp
The other exception is regular expression matching. If the realm name starts
with a \fB/\fR, the name is treated as an regular expression. A case insensitive
regexp match will then be done using this regexp on the value of the entire
Username attribute. Optionally you may also have a trailing \fB/\fR after the
regexp. So as an example, if you want to use regexp matching the domain
\fBexample.com\fR you could have a realm block named \fB/@example\\.com$\fR.
Optinally this can also be written \fB/@example\\.com$/\fR. If you want to
match all domains under the \fB.com\fR top domain, you could do
\fB/@.*\\.com$\fR. Note that since the matching is done on the entire
attribute value, you can also use rules like \fB/^[a-k].*@example\\.com$/\fR
to get some of the users in this domain to use one server, while other users
could be matched by another realm block and use another server.
.sp 

.TP
\fBRealm block options\fR
.sp
A realm block may contain at most one \fBserver\fR option. If defined, the
value of the \fBserver\fR option must be the name of a previously defined
server block, and this will be the server that the request is forwarded to.
.sp
If there is no \fBserver\fR option, the proxy will reply back to the client
with an Access Reject message. Note that this is different from having no
match since then the request is simply ignored. You may wonder why this is
useful. One example is if you handle say all domains under say \fB.bv\fR.
Then you may have several realm blocks matching the domains that exists,
while for other domains under \fB.bv\fR you want to send a reject. At the
same time you might want to send all other requests to some default server.
After the realms for the subdomains, you would then have two realm
definitions. One with the name \fB/@.*\\.bv$\fR with no servers, followed
by one with the name \fB*\fR with the default server defined. This may also
be useful for blocking particular usernames.
.sp
When sending reject messages, the proxy will check if the option
\fBreplyMessage\fR is set for the realm. If it is, it will add a replyMessage
attribute to the reject message with this value. Note that you need to quote
the message if it contains white space.
.sp

.SH "TLS BLOCK"
The TLS block specifies TLS configuration options and you need at least one
of these if you have clients or servers using TLS. As discussed in the client
and server block descriptions, a client or server block may reference a
particular TLS block by name. There are also however the special TLS block
names \fBdefault\fR, \fBdefaultclient\fR and \fBdefaultserver\fR which are
used as defaults if the client or server block does not reference a TLS block.
Also note that a TLS block must be defined before the client or server block
that would use it. If you want the same TLS configuration for all TLS clients
and servers, you need just a single TLS block named \fBdefault\fR, and the client
and servers need not refer to it. If you want all TLS clients to use one
config, and all TLS servers to use another, then you would be fine only
defining two TLS blocks named \fBdefaultclient\fR and \fBdefaultserver\fR.
If you want different clients (or different servers) to have different TLS
parameters, then you may need to create other TLS blocks with other names,
and reference those from the client or server definitions. Note that you could
also have say a client block refer to a default, even \fBdefaultserver\fR
if you really want to.
.sp
The available TLS block options are \fBCACertificateFile\fR,
\fBCACertificatePath\fR, \fBCertificateFile\fR, \fBCertificateKeyFile\fR
and \fBCertificateKeyPassword\fR. When doing RADIUS over TLS, both the
client and the server present certificates, and they are both verified
by the peer. Hence you must always specify \fBCertificateFile\fR and
\fBCertificateKeyFile\fR options, as well as \fBCertificateKeyPassword\fR
if a password is needed to decrypt the private key. Note that
\fBCACertificateFile\fR may be a certificate chain. In order to verify
certificates, or send a chain of certificates to a peer, you also always
need to specify \fBCACertificateFile\fR or \fBCACertificatePath\fR. Note
that you may specify both, in which case the certificates in
\fBCACertificateFile\fR are checked first.

.SH "SEE ALSO"
radsecproxy(1), RadSec draft paper.