Basic Dropbear build instructions:

- Edit localoptions.h to set which features you want. Available options
  are described in default_options.h, these will be overridden by
  anything set in localoptions.h
  localoptions.h should be located in the build directory if you are
  building out of tree.

- If using a Mercurial or Git checkout, "autoconf; autoheader"

- Configure for your system:
  ./configure     (optionally with --disable-zlib or --disable-syslog,
                  or --help for other options)

- Compile:

  make PROGRAMS="dropbear dbclient dropbearkey dropbearconvert scp"

- Optionally install, or copy the binaries another way

  make install (/usr/local/bin is usual default):

  or

  make PROGRAMS="dropbear dbclient dropbearkey dropbearconvert scp" install

(you can leave items out of the PROGRAMS list to avoid compiling them. If you
recompile after changing the PROGRAMS list, you *MUST* "make clean" before
recompiling - bad things will happen otherwise)

See MULTI for instructions on making all-in-one binaries.

If you want to compile statically use ./configure --enable-static

By default Dropbear adds various build flags that improve robustness 
against programming bugs (good for security). If these cause problems
they can be disabled with ./configure --disable-harden

Binaries can be stripped with "make strip"

============================================================================

If you're compiling for a 386-class CPU, you will probably need to add
CFLAGS=-DLTC_NO_BSWAP so that libtomcrypt doesn't use 486+ instructions.

============================================================================

Compiling with uClibc:

Firstly, make sure you have at least uclibc 0.9.17, as getusershell() in prior
versions is broken. Also note that you may get strange issues if your uClibc
headers don't match the library you are running with, ie the headers might
say that shadow password support exists, but the libraries don't have it.

Compiling for uClibc should be the same as normal, just set CC to the magic
uClibc toolchain compiler (ie export CC=i386-uclibc-gcc or whatever).
You can use "make STATIC=1" to make statically linked binaries, and it is
advisable to strip the binaries too. If you're looking to make a small binary,
you should remove unneeded ciphers and MD5, by editing options.h

It is possible to compile zlib in, by copying zlib.h and zconf.h into a
subdirectory (ie zlibincludes), and 

export CFLAGS="-Izlibincludes -I../zlibincludes"
export LDFLAGS=/usr/lib/libz.a

before ./configure and make.

If you disable zlib, you must explicitly disable compression for the client -
OpenSSH is possibly buggy in this regard, it seems you need to disable it
globally in ~/.ssh/config, not just in the host entry in that file.

You may want to manually disable lastlog recording when using uClibc, configure
with --disable-lastlog.

One common problem is pty allocation. There are a number of types of pty
allocation which can be used -- if they work properly, the end result is the
same for each type. Running configure should detect the best type to use
automatically, however for some systems, this may be incorrect. Some
things to note:

    If your system expects /dev/pts to be mounted (this is a uClibc option),
	make sure that it is.

	Make sure that your libc headers match the library version you are using.

	If openpty() is being used (HAVE_OPENPTY defined in config.h) and it fails,
	you can try compiling with --disable-openpty. You will probably then need
	to create all the /dev/pty?? and /dev/tty?? devices, which can be
	problematic for devfs. In general, openpty() is the best way to allocate
	PTYs, so it's best to try and get it working.