Mercurial > dropbear

annotate SMALL @ 404:a588558bfc94

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Fix potential null pointer dereference found by Klokwork
author Matt Johnston <matt@ucc.asn.au>
date Sat, 03 Feb 2007 09:58:14 +0000
parents b9d3f725e00b
children 13cb8cc1b0e4
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
161
b9d3f725e00b 0.44 release changes
Matt Johnston <matt@ucc.asn.au>
parents: 4
diff changeset
3 If you only want server functionality (for example), compile with
b9d3f725e00b 0.44 release changes
Matt Johnston <matt@ucc.asn.au>
parents: 4
diff changeset
4 make PROGRAMS=dropbear
b9d3f725e00b 0.44 release changes
Matt Johnston <matt@ucc.asn.au>
parents: 4
diff changeset
5 rather than just
b9d3f725e00b 0.44 release changes
Matt Johnston <matt@ucc.asn.au>
parents: 4
diff changeset
6 make dropbear
b9d3f725e00b 0.44 release changes
Matt Johnston <matt@ucc.asn.au>
parents: 4
diff changeset
7 so that client functionality in shared portions of Dropbear won't be included.
b9d3f725e00b 0.44 release changes
Matt Johnston <matt@ucc.asn.au>
parents: 4
diff changeset
8 The same applies if you are compiling just a client.
4
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
9
161
b9d3f725e00b 0.44 release changes
Matt Johnston <matt@ucc.asn.au>
parents: 4
diff changeset
10 ---
b9d3f725e00b 0.44 release changes
Matt Johnston <matt@ucc.asn.au>
parents: 4
diff changeset
11
b9d3f725e00b 0.44 release changes
Matt Johnston <matt@ucc.asn.au>
parents: 4
diff changeset
12 The following are set in options.h:
4
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
13
161
b9d3f725e00b 0.44 release changes
Matt Johnston <matt@ucc.asn.au>
parents: 4
diff changeset
14 - You can safely disable blowfish and twofish ciphers, and MD5 hmac, without
b9d3f725e00b 0.44 release changes
Matt Johnston <matt@ucc.asn.au>
parents: 4
diff changeset
15 affecting interoperability
b9d3f725e00b 0.44 release changes
Matt Johnston <matt@ucc.asn.au>
parents: 4
diff changeset
16
b9d3f725e00b 0.44 release changes
Matt Johnston <matt@ucc.asn.au>
parents: 4
diff changeset
17 - If you're compiling statically, you can turn off host lookups
4
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
18
161
b9d3f725e00b 0.44 release changes
Matt Johnston <matt@ucc.asn.au>
parents: 4
diff changeset
19 - You can disable either password or public-key authentication, though note
b9d3f725e00b 0.44 release changes
Matt Johnston <matt@ucc.asn.au>
parents: 4
diff changeset
20 that the IETF draft states that pubkey authentication is required.
4
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
21
161
b9d3f725e00b 0.44 release changes
Matt Johnston <matt@ucc.asn.au>
parents: 4
diff changeset
22 - Similarly with DSS and RSA, you can disable one of these if you know that
b9d3f725e00b 0.44 release changes
Matt Johnston <matt@ucc.asn.au>
parents: 4
diff changeset
23 all clients will be able to support a particular one. The IETF draft
b9d3f725e00b 0.44 release changes
Matt Johnston <matt@ucc.asn.au>
parents: 4
diff changeset
24 states that DSS is required, however you may prefer to use RSA.
b9d3f725e00b 0.44 release changes
Matt Johnston <matt@ucc.asn.au>
parents: 4
diff changeset
25 DON'T disable either of these on systems where you aren't 100% sure about
b9d3f725e00b 0.44 release changes
Matt Johnston <matt@ucc.asn.au>
parents: 4
diff changeset
26 who will be connecting and what clients they will be using.
4
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
27
161
b9d3f725e00b 0.44 release changes
Matt Johnston <matt@ucc.asn.au>
parents: 4
diff changeset
28 - Disabling the MOTD code and SFTP-SERVER may save a small amount of codesize
b9d3f725e00b 0.44 release changes
Matt Johnston <matt@ucc.asn.au>
parents: 4
diff changeset
29
b9d3f725e00b 0.44 release changes
Matt Johnston <matt@ucc.asn.au>
parents: 4
diff changeset
30 - You can disable x11, tcp and agent forwarding as desired. None of these are
b9d3f725e00b 0.44 release changes
Matt Johnston <matt@ucc.asn.au>
parents: 4
diff changeset
31 essential, although agent-forwarding is often useful even on firewall boxes.
b9d3f725e00b 0.44 release changes
Matt Johnston <matt@ucc.asn.au>
parents: 4
diff changeset
32
b9d3f725e00b 0.44 release changes
Matt Johnston <matt@ucc.asn.au>
parents: 4
diff changeset
33 ---
4
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
34
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
35 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
36 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
37
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
38 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
39 the functions into one binary, avoiding repeated code.
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
40
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
41 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
42 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
43
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
44 LDFLAGS=-Wl,--gc-sections
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
45 CFLAGS="-ffunction-sections -fdata-sections"
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
46
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
47 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
48 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
49 deciding.
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
50
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
51 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
52
fe6bca95afa7 Makefile.in contains updated files required
Matt Johnston <matt@ucc.asn.au>
parents:
diff changeset
53 If you have any queries, mail me and I'll see if I can help.