mirror of
http://galexander.org/git/simplesshd.git
synced 2024-11-30 19:28:10 +00:00
54 lines
2.0 KiB
Plaintext
54 lines
2.0 KiB
Plaintext
|
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.
|