Provided by: strongswan-starter_5.9.8-3ubuntu4_amd64 
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.
# /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 RSA), an entry with multiple selectors will match a host and peer even
if only the host ID matches a selector (it is presumed that the selectors are all
identities of the host). It is acceptable for two entries to be the best match as long as
they agree about the secret or private key.
Authentication by preshared secret requires that both systems find the 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 with 0s
is interpreted as Base64 encoded binary data.
: RSA <private key file> [ <passphrase> | %prompt ]
: ECDSA <private key file> [ <passphrase> | %prompt ]
For the private key file both absolute paths or paths relative to
/etc/ipsec.d/private are accepted. If the private key file 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 key.
: P12 <PKCS#12 file> [ <passphrase> | %prompt ]
For the PKCS#12 file both absolute paths or paths relative to /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
/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.