X-Git-Url: https://git.distorted.org.uk/~mdw/secnet/blobdiff_plain/b02b720ac62afd3a45c44e7ced37c090e7b39da9..HEAD:/secnet.8

diff --git a/secnet.8 b/secnet.8
index 2bf2250..9ffa605 100644
--- a/secnet.8
+++ b/secnet.8
@@ -1,3 +1,21 @@
+.\" Man page for secnet.
+.\"
+.\" See the secnet.git README, or the Debian copyright file, for full
+.\" list of copyright holders.
+.\"
+.\" secnet is free software; you can redistribute it and/or modify it
+.\" under the terms of the GNU General Public License as published by
+.\" the Free Software Foundation; either version 3 of the License, or
+.\" (at your option) any later version.
+.\" 
+.\" secnet is distributed in the hope that it will be useful, but
+.\" WITHOUT ANY WARRANTY; without even the implied warranty of
+.\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+.\" General Public License for more details.
+.\" 
+.\" You should have received a copy of the GNU General Public License
+.\" version 3 along with secnet; if not, see
+.\" https://www.gnu.org/licenses/gpl.html.
 .TH secnet 8
 
 .SH NAME
@@ -266,7 +284,6 @@ Boolean.
 If \fBtrue\fR (the default) then check if \fIp\fR is prime.
 .PP
 A \fIdh closure\fR defines a group to be used for key exchange.
-The same group must be used by all sites in the VPN.
 
 .SS logfile
 \fBlogfile(\fIDICT\fB)\fR => \fIlog closure\fR
@@ -416,7 +433,7 @@ A \fIrandomsource closure\fR is a source of random numbers.
 Read the contents of the file \fIPATH\fR (a string) and return it as a string.
 
 .SS eax-serpent
-\eax-fBserpent(\fIDICT\fB)\fR => \fItransform closure\fR
+\fBeax-serpent(\fIDICT\fB)\fR => \fItransform closure\fR
 .PP
 Valid keys in the \fIDICT\fR argument are:
 .TP
@@ -434,6 +451,17 @@ blocksize, 16.  Must be have the same value at both ends.
 .B padding-rounding
 Messages are padded to a multiple of this many bytes.  This
 serves to obscure the exact length of messages.  The default is 16,
+.TP
+.B capab-num
+The transform capability number to use when advertising this
+transform.  Both ends must have the same meaning (or, at least, a
+compatible transform) for each transform capability number they have
+in common.  The default for serpent-eax is 9.
+.IP
+Transform capability numbers in the range 8..15 are intended for
+allocation by the implementation, and may be assigned as the default
+for new transforms in the future.  Transform capability numbers in the
+range 0..7 are reserved for definition by the user.
 .PP
 A \fItransform closure\fR is a reversible means of transforming
 messages for transmission over a (presumably) insecure network.
@@ -442,8 +470,15 @@ It is responsible for both confidentiality and integrity.
 .SS serpent256-cbc
 \fBserpent256-cbc(\fIDICT\fB)\fR => \fItransform closure\fR
 .PP
+This transform
+is deprecated as its security properties are poor; it should be
+specified only alongside a better transform such as eax-serpent.
+.PP
 Valid keys in the \fIDICT\fR argument are:
 .TP
+.B capab-num
+As above.  The default for serpent256-cbc is 8.
+.TP
 .B max-sequence-skew
 As above.
 .PP
@@ -520,8 +555,13 @@ An \fIrsapubkey closure\fR.
 The key used to verify the peer's identity.
 .TP
 .B transform
-A \fItransform closure\fR.
-Used to protect packets exchanged with the peer.
+One or more \fItransform closures\fR.
+Used to protect packets exchanged with the peer.  These should
+all have distinct \fBcapab-num\fR values, and the same \fBcapab-num\fR
+value should refer to the same (or a compatible) transform at both
+ends.  The list should be in order of preference, most preferred
+first.  (The end which sends MSG1,MSG3 ends up choosing; the ordering
+at the other end is irrelevant.)
 .TP
 .B dh
 A \fIdh closure\fR.