diff SMALL @ 389:5ff8218bcee9

propagate from branch 'au.asn.ucc.matt.ltm.dropbear' (head 2af95f00ebd5bb7a28b3817db1218442c935388e) to branch 'au.asn.ucc.matt.dropbear' (head ecd779509ef23a8cdf64888904fc9b31d78aa933)
author Matt Johnston <matt@ucc.asn.au>
date Thu, 11 Jan 2007 03:14:55 +0000
parents b9d3f725e00b
children 13cb8cc1b0e4
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/SMALL	Thu Jan 11 03:14:55 2007 +0000
@@ -0,0 +1,53 @@
+Tips for a small system:
+
+If you only want server functionality (for example), compile with
+	make PROGRAMS=dropbear
+rather than just
+	make dropbear
+so that client functionality in shared portions of Dropbear won't be included.
+The same applies if you are compiling just a client.
+
+---
+
+The following are set in options.h:
+
+	- You can safely disable blowfish and twofish ciphers, and MD5 hmac, without
+	  affecting interoperability
+
+	- If you're compiling statically, you can turn off host lookups
+
+	- You can disable either password or public-key authentication, though note
+	  that the IETF draft states that pubkey authentication is required.
+
+	- Similarly with DSS and RSA, you can disable one of these if you know that
+	  all clients will be able to support a particular one. The IETF draft
+	  states that DSS is required, however you may prefer to use RSA. 
+	  DON'T disable either of these on systems where you aren't 100% sure about
+	  who will be connecting and what clients they will be using.
+
+	- Disabling the MOTD code and SFTP-SERVER may save a small amount of codesize
+
+	- You can disable x11, tcp and agent forwarding as desired. None of these are
+	  essential, although agent-forwarding is often useful even on firewall boxes.
+
+---
+
+If you are compiling statically, you may want to disable zlib, as it will use
+a few tens of kB of binary-size (./configure --disable-zlib).
+
+You can create a combined binary, see the file MULTI, which will put all
+the functions into one binary, avoiding repeated code.
+
+If you're compiling with gcc, you might want to look at gcc's options for
+stripping unused code. The relevant vars to set before configure are:
+
+LDFLAGS=-Wl,--gc-sections
+CFLAGS="-ffunction-sections -fdata-sections"
+
+You can also experiment with optimisation flags such as -Os, note that in some
+cases these flags actually seem to increase size, so experiment before
+deciding.
+
+Of course using small C libraries such as uClibc and dietlibc can also help.
+
+If you have any queries, mail me and I'll see if I can help.