1IPSEC.SECRETS(5) strongSwan IPSEC.SECRETS(5)
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6 ipsec.secrets - secrets for IKE/IPsec authentication
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9 The file ipsec.secrets holds a table of secrets. These secrets are
10 used by the strongSwan Internet Key Exchange (IKE) daemons pluto
11 (IKEv1) and charon (IKEv2) to authenticate other hosts.
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13 It is vital that these secrets be protected. The file should be owned
14 by the super-user, and its permissions should be set to block all ac‐
15 cess by others.
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17 The file is a sequence of entries and include directives. Here is an
18 example.
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20 # /etc/ipsec.secrets - strongSwan IPsec secrets file
21 192.168.0.1 %any : PSK "v+NkxY9LLZvwj4qCC2o/gGrWDF2d21jL"
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23 : RSA moonKey.pem
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25 alice@strongswan.org : EAP "x3.dEhgN"
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27 carol : XAUTH "4iChxLT3"
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29 dave : XAUTH "ryftzG4A"
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31 # get secrets from other files
32 include ipsec.*.secrets
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34 Each entry in the file is a list of optional ID selectors, followed by
35 a secret. The two parts are separated by a colon (:) that is sur‐
36 rounded by whitespace. If no ID selectors are specified the line must
37 start with a colon.
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39 A selector is an IP address, a Fully Qualified Domain Name, user@FQDN,
40 %any or %any6 (other kinds may come).
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42 Matching IDs with selectors is fairly straightforward: they have to be
43 equal. In the case of a ``Road Warrior'' connection, if an equal match
44 is not found for the Peer's ID, and it is in the form of an IP address,
45 a selector of %any will match the peer's IP address if IPV4 and %any6
46 will match a the peer's IP address if IPV6. Currently, the obsolete
47 notation 0.0.0.0 may be used in place of %any.
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49 In IKEv1 an additional complexity arises in the case of authentication
50 by preshared secret: the responder will need to look up the secret be‐
51 fore the Peer's ID payload has been decoded, so the ID used will be the
52 IP address.
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54 To authenticate a connection between two hosts, the entry that most
55 specifically matches the host and peer IDs is used. An entry with no
56 selectors will match any host and peer. More specifically, an entry
57 with one selector will match a host and peer if the selector matches
58 the host's ID (the peer isn't considered). Still more specifically, an
59 entry with multiple selectors will match a host and peer if the host ID
60 and peer ID each match one of the selectors. If the key is for an
61 asymmetric authentication technique (i.e. a public key system such as
62 RSA), an entry with multiple selectors will match a host and peer even
63 if only the host ID matches a selector (it is presumed that the selec‐
64 tors are all identities of the host). It is acceptable for two entries
65 to be the best match as long as they agree about the secret or private
66 key.
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68 Authentication by preshared secret requires that both systems find the
69 identical secret (the secret is not actually transmitted by the IKE
70 protocol). If both the host and peer appear in the selector list, the
71 same entry will be suitable for both systems so verbatim copying be‐
72 tween systems can be used. This naturally extends to larger groups
73 sharing the same secret. Thus multiple-selector entries are best for
74 PSK authentication.
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76 Authentication by public key systems such as RSA requires that each
77 host have its own private key. A host could reasonably use a different
78 private keys for different interfaces and for different peers. But it
79 would not be normal to share entries between systems. Thus thus no-se‐
80 lector and one-selector forms of entry often make sense for public key
81 authentication.
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83 The key part of an entry must start with a token indicating the kind of
84 key. The following types of secrets are currently supported:
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86 PSK defines a pre-shared key
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88 RSA defines an RSA private key
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90 ECDSA defines an ECDSA private key
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92 P12 defines a PKCS#12 container
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94 EAP defines EAP credentials
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96 NTLM defines NTLM credentials
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98 XAUTH defines XAUTH credentials
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100 PIN defines a smartcard PIN
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102 Details on each type of secret are given below.
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104 Whitespace at the end of a line is ignored. At the start of a line or
105 after whitespace, # and the following text up to the end of the line is
106 treated as a comment.
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108 An include directive causes the contents of the named file to be pro‐
109 cessed before continuing with the current file. The filename is sub‐
110 ject to ``globbing'' as in sh(1), so every file with a matching name is
111 processed. Includes may be nested to a modest depth (10, currently).
112 If the filename doesn't start with a /, the directory containing the
113 current file is prepended to the name. The include directive is a line
114 that starts with the word include, followed by whitespace, followed by
115 the filename (which must not contain whitespace).
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117 TYPES OF SECRETS
118 [ <selectors> ] : PSK <secret>
119 A preshared secret is most conveniently represented as a se‐
120 quence of characters, which is delimited by double-quote charac‐
121 ters ("). The sequence cannot contain newline or double-quote
122 characters.
123 Alternatively, preshared secrets can be represented as hexadeci‐
124 mal or Base64 encoded binary values. A character sequence begin‐
125 ning with 0x is interpreted as sequence of hexadecimal digits.
126 Similarly, a character sequence beginning with 0s is interpreted
127 as Base64 encoded binary data.
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129 : RSA <private key file> [ <passphrase> | %prompt ]
130 : ECDSA <private key file> [ <passphrase> | %prompt ]
131 For the private key file both absolute paths or paths relative
132 to /etc/ipsec.d/private are accepted. If the private key file is
133 encrypted, the passphrase must be defined. Instead of a
134 passphrase %prompt can be used which then causes the daemon to
135 ask the user for the password whenever it is required to decrypt
136 the key.
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138 : P12 <PKCS#12 file> [ <passphrase> | %prompt ]
139 For the PKCS#12 file both absolute paths or paths relative to
140 /etc/ipsec.d/private are accepted. If the container is en‐
141 crypted, the passphrase must be defined. Instead of a passphrase
142 %prompt can be used which then causes the daemon to ask the user
143 for the password whenever it is required to decrypt the con‐
144 tainer. Private keys, client and CA certificates are extracted
145 from the container. To use such a client certificate in a con‐
146 nection set leftid to one of the subjects of the certificate.
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148 <user id> : EAP <secret>
149 The format of secret is the same as that of PSK secrets.
150 EAP secrets are IKEv2 only.
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152 <user id> : NTLM <secret>
153 The format of secret is the same as that of PSK secrets, but the
154 secret is stored as NTLM hash, which is MD4(UTF-16LE(secret)),
155 instead of as cleartext.
156 NTLM secrets can only be used with the eap-mschapv2 plugin.
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158 [ <servername> ] <username> : XAUTH <password>
159 The format of password is the same as that of PSK secrets.
160 XAUTH secrets are IKEv1 only.
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162 : PIN %smartcard[<slot nr>[@<module>]]:<keyid> <pin code> | %prompt
163 The smartcard selector always requires a keyid to uniquely se‐
164 lect the correct key. The slot number defines the slot on the
165 token, the module name refers to the module name defined in
166 strongswan.conf(5). Instead of specifying the pin code stati‐
167 cally, %prompt can be specified, which causes the daemon to ask
168 the user for the pin code.
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171 /etc/ipsec.secrets
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174 ipsec.conf(5), strongswan.conf(5), ipsec(8)
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177 Originally written for the FreeS/WAN project by D. Hugh Redelmeier.
178 Updated and extended for the strongSwan project
179 <http://www.strongswan.org> by Tobias Brunner and Andreas Steffen.
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182 If an ID is 0.0.0.0, it will match %any; if it is 0::0, it will match
183 %any6.
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1875.9.2 2011-12-14 IPSEC.SECRETS(5)