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IPSEC.SECRETS(5) strongSwan IPSEC.SECRETS(5)
NAME
ipsec.secrets - secrets for IKE/IPsec authentication
DESCRIPTION
The file ipsec.secrets holds a table of secrets. These secrets are
used by the strongSwan Internet Key Exchange (IKE) daemons pluto
(IKEv1) and charon (IKEv2) to authenticate other hosts.
It is vital that these secrets be protected. The file should be owned
by the super-user, and its permissions should be set to block all
access by others.
The file is a sequence of entries and include directives. Here is an
example.
# /usr/local/etc/ipsec.secrets - strongSwan IPsec secrets file
192.168.0.1 %any : PSK "v+NkxY9LLZvwj4qCC2o/gGrWDF2d21jL"
: RSA moonKey.pem
alice@strongswan.org : EAP "x3.dEhgN"
carol : XAUTH "4iChxLT3"
dave : XAUTH "ryftzG4A"
# get secrets from other files
include ipsec.*.secrets
Each entry in the file is a list of optional ID selectors, followed by
a secret. The two parts are separated by a colon (:) that is
surrounded by whitespace. If no ID selectors are specified the line
must start with a colon.
A selector is an IP address, a Fully Qualified Domain Name, user@FQDN,
%any or %any6 (other kinds may come).
Matching IDs with selectors is fairly straightforward: they have to be
equal. In the case of a ``Road Warrior'' connection, if an equal match
is not found for the Peer's ID, and it is in the form of an IP address,
a selector of %any will match the peer's IP address if IPV4 and %any6
will match a the peer's IP address if IPV6. Currently, the obsolete
notation 0.0.0.0 may be used in place of %any.
In IKEv1 an additional complexity arises in the case of authentication
by preshared secret: the responder will need to look up the secret
before the Peer's ID payload has been decoded, so the ID used will be
the IP address.
To authenticate a connection between two hosts, the entry that most
specifically matches the host and peer IDs is used. An entry with no
selectors will match any host and peer. More specifically, an entry
with one selector will match a host and peer if the selector matches
the host's ID (the peer isn't considered). Still more specifically, an
entry with multiple selectors will match a host and peer if the host ID
and peer ID each match one of the selectors. If the key is for an
asymmetric authentication technique (i.e. a public key system such as
identical secret (the secret is not actually transmitted by the IKE
protocol). If both the host and peer appear in the selector list, the
same entry will be suitable for both systems so verbatim copying
between systems can be used. This naturally extends to larger groups
sharing the same secret. Thus multiple-selector entries are best for
PSK authentication.
Authentication by public key systems such as RSA requires that each
host have its own private key. A host could reasonably use a different
private keys for different interfaces and for different peers. But it
would not be normal to share entries between systems. Thus thus no-
selector and one-selector forms of entry often make sense for public
key authentication.
The key part of an entry must start with a token indicating the kind of
key. The following types of secrets are currently supported:
PSK defines a pre-shared key
RSA defines an RSA private key
ECDSA defines an ECDSA private key
P12 defines a PKCS#12 container
EAP defines EAP credentials
NTLM defines NTLM credentials
XAUTH defines XAUTH credentials
PIN defines a smartcard PIN
Details on each type of secret are given below.
Whitespace at the end of a line is ignored. At the start of a line or
after whitespace, # and the following text up to the end of the line is
treated as a comment.
An include directive causes the contents of the named file to be
processed before continuing with the current file. The filename is
subject to ``globbing'' as in sh(1), so every file with a matching name
is processed. Includes may be nested to a modest depth (10,
currently). If the filename doesn't start with a /, the directory
containing the current file is prepended to the name. The include
directive is a line that starts with the word include, followed by
whitespace, followed by the filename (which must not contain
whitespace).
TYPES OF SECRETS
[ <selectors> ] : PSK <secret>
A preshared secret is most conveniently represented as a
sequence of characters, which is delimited by double-quote
characters ("). The sequence cannot contain newline or double-
quote characters.
Alternatively, preshared secrets can be represented as
hexadecimal or Base64 encoded binary values. A character
sequence beginning with 0x is interpreted as sequence of
hexadecimal digits. Similarly, a character sequence beginning
of a passphrase %prompt can be used which then causes the daemon
to ask the user for the password whenever it is required to
decrypt the key.
: P12 <PKCS#12 file> [ <passphrase> | %prompt ]
For the PKCS#12 file both absolute paths or paths relative to
/usr/local/etc/ipsec.d/private are accepted. If the container is
encrypted, the passphrase must be defined. Instead of a
passphrase %prompt can be used which then causes the daemon to
ask the user for the password whenever it is required to decrypt
the container. Private keys, client and CA certificates are
extracted from the container. To use such a client certificate
in a connection set leftid to one of the subjects of the
certificate.
<user id> : EAP <secret>
The format of secret is the same as that of PSK secrets.
EAP secrets are IKEv2 only.
<user id> : NTLM <secret>
The format of secret is the same as that of PSK secrets, but the
secret is stored as NTLM hash, which is MD4(UTF-16LE(secret)),
instead of as cleartext.
NTLM secrets can only be used with the eap-mschapv2 plugin.
[ <servername> ] <username> : XAUTH <password>
The format of password is the same as that of PSK secrets.
XAUTH secrets are IKEv1 only.
: PIN %smartcard[<slot nr>[@<module>]]:<keyid> <pin code> | %prompt
The smartcard selector always requires a keyid to uniquely
select the correct key. The slot number defines the slot on the
token, the module name refers to the module name defined in
strongswan.conf(5). Instead of specifying the pin code
statically, %prompt can be specified, which causes the daemon to
ask the user for the pin code.
FILES
/usr/local/etc/ipsec.secrets
SEE ALSO
ipsec.conf(5), strongswan.conf(5), ipsec(8)
HISTORY
Originally written for the FreeS/WAN project by D. Hugh Redelmeier.
Updated and extended for the strongSwan project
<http://www.strongswan.org> by Tobias Brunner and Andreas Steffen.
BUGS
If an ID is 0.0.0.0, it will match %any; if it is 0::0, it will match
%any6.
5.9.13 2011-12-14 IPSEC.SECRETS(5)