Mercurial > dropbear

annotate SMALL @ 56:6f091656c100

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
newlines which weren't there
author Matt Johnston <matt@ucc.asn.au>
date Sun, 08 Aug 2004 16:57:00 +0000
parents fe6bca95afa7
children b9d3f725e00b
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
4
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
1 Tips for a small system:
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
2
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
3 The following are set in options.h
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
4
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
5 - You can safely disable blowfish and twofish ciphers, and MD5 hmac, without
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
6 affecting interoperability
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
7
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
8 - If you're compiling statically, you can turn off host lookups
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
9
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
10 - You can disable either password or public-key authentication, though note
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
11 that the IETF draft states that pubkey authentication is required.
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
12
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
13 - Similarly with DSS and RSA, you can disable one of these if you know that
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
14 all clients will be able to support a particular one. The IETF draft
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
15 states that DSS is required, however you may prefer to use RSA.
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
16 DON'T disable either of these on systems where you aren't 100% sure about
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
17 who will be connecting and what clients they will be using.
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
18
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
19 - Disabling the MOTD code and SFTP-SERVER may save a small amount of codesize
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
20
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
21 - You can disable x11, tcp and agent forwarding as desired. None of these are
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
22 essential, although agent-forwarding is often useful even on firewall boxes.
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
23
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
24 If you are compiling statically, you may want to disable zlib, as it will use
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
25 a few tens of kB of binary-size (./configure --disable-zlib).
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
26
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
27 You can create a combined binary, see the file MULTI, which will put all
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
28 the functions into one binary, avoiding repeated code.
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
29
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
30 If you're compiling with gcc, you might want to look at gcc's options for
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
31 stripping unused code. The relevant vars to set before configure are:
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
32
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
33 LDFLAGS=-Wl,--gc-sections
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
34 CFLAGS="-ffunction-sections -fdata-sections"
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
35
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
36 You can also experiment with optimisation flags such as -Os, note that in some
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
37 cases these flags actually seem to increase size, so experiment before
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
38 deciding.
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
39
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
40 Of course using small C libraries such as uClibc and dietlibc can also help.
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
41
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
42 If you have any queries, mail me and I'll see if I can help.