How to configure and install nail
=================================

Quick start
-----------

        make
        make install

No 'configure' step is necessary anymore. If 'make install' fails because
no /usr/ucb/install program is present, try

        make install UCBINSTALL=/usr/bin/install

Detailed description
--------------------

Path names are configurable as Makefile variables:

PREFIX          The default Makefile puts BINDIR and MANDIR below this.

BINDIR          The nail binary is installed there.

MANDIR          The nail manual page is put in $(MANDIR)/man1.

SYSCONFDIR      nail.rc is installed in this directory unless it already
                exists.

MAILSPOOL       The directory where the mail files of users are stored
                under their respective names and in mbox format. If only
                POP3 is used to read mail, the value does not matter.

SENDMAIL        Path to the de-facto standard /usr/lib/sendmail interface
                normally offered by Unix MTAs. If only SMTP is used to send
                mail, the value does not matter.

DESTDIR         Prepended to BINDIR, MANDIR etc. at 'make install'. Mostly
                useful for package building.

UCBINSTALL      Path name to a BSD-style install, like /usr/ucb/install on
                SVR4 or GNU install.

Nail uses a simple shell script named 'makeconfig' to check for header
files and library functions. It is automatically invoked by 'make all'.
The script generates three files, 'config.h', 'LIBS', and 'config.log'.
'config.h' is included as usual, 'LIBS' contains options for the linker,
and 'config.log' contains all test programs and test results. Neither of
these files is changed by make once it exists until 'make mrproper' is
run, so they can be edited by hand without much fear of losing them.

Useful Makefile targets:

all             Initiates the build; just type 'make'.

install         Installs the binary and the manual page. If the systemwide
                configuration file is not present already, is is also
                installed.

clean           Removes object files.

mrproper        Removes object files and the configuration results.

Makefile variables to control the build process:

CFLAGS          Flags for the C compiler, such as '-O'.

CPPFLAGS        Flags for the C preprocessor.

INCLUDES        A list of additional include file directories, as
                '-I/usr/local/include'. Use this to locate the include
                files for NSS, OpenSSL, or iconv(3), if they are not present
                in the standard include directories. Also, some versions
                of RedHat Linux need -I/usr/kerberos/include to compile
                with OpenSSL, or to compile with GSSAPI authentication
                included.

LDFLAGS         Flags for the linker. To compile with GSSAPI authentication
                included, some RedHat versions need -L/usr/kerberos/lib.
                Also use this to specify the NSS or OpenSSL library path.

LIBS            A list of additional libraries such as '-lfoo'. -lsocket,
                -lnsl, -lssl, -lcrypto, -liconv, and NSS libraries are
		automatically included by makeconfig and should not be
		put into this.

As usual with Makefile variables, you can pass these values to make in
the environment or on the command line. Thus if you want to avoid to edit
the Makefile, you can create a shell script to invoke make, or set flags
of general use (such as CFLAGS) in .profile. Note that passing flags on
the command line does not override those specified in the Makefile itself
with several commercial versions of make in combination with the recursive
make calls that are executed at configuration time.


Transition remarks concerning the old configure system
======================================================

* --prefix and other common configure options: Path names can be specified
  in the Makefile or as assignment arguments to make.

* --with-openssl: No longer available. Nail is always built with OpenSSL
  support if possible. If you really want to have a nail binary without
  OpenSSL support, edit config.h after running 'make config.h'.

* --enable-all-chars: No longer available at compile time. 'print-all-chars'
  can be set in nail in those cases where use of this option was necessary.

* --with-rcfile, --with-mailspool, --with-sendmail: These path names can
  be set in the Makefile or as arguments to make.

* --with-csh: No longer used. Nail now uses /bin/sh for executing commands
  if the SHELL variable is not set.

* --with-more, --with-pg, --with-ed, --with-vi: No longer available. If the
  PAGER, EDITOR, or VISUAL variables are not set, the executable is looked
  up using $PATH.

* --with-catname=NAME: Contact the author if you want usable message
  catalogue support.

In short, if you were using
--------

        ./configure --prefix=/opt/nail --with-rcfile=/opt/nail/etc/nail.rc

up to now, replace it by

        make PREFIX=/opt/nail SYSCONFDIR=/opt/nail/etc

The DESTDIR variable for building packages is available as before.
If you intend to build nail packages, a look at 'nail.spec' might
be helpful - even if you don't use RPM, the process is likely to
be similar.


Why autoconf/automake are no longer used
========================================

Autoconf and automake are systems of considerable complexity which
one must know well to make real use of them. The autoconf/automake
scripts for nail were supplied by a contributor in 2000 and were
out of date as of 2004; they wouldn't work with recent versions of
automake, in particular. But I'm not very interested in learning
automake myself, and I'm absolutely not interested in keeping such
knowledge up-to-date with new automake versions.

Furthermore, I've made some horrible hacks for the autoconf/automake
scripts in previous versions (such as --with-rcfile) because once one
doesn't like some particular behavior of them, working around can be
difficult. Such hacks are unnecessary now.

The new build system needs approximately the same number of lines
as just the maintainer-supplied portions of the old autoconf/automake
system did. Since it is written in standard languages (shell and make),
any Unix developer can read and understand it; to make adjustments to
it, no special versions of third-party tools are needed. Every serious
developer should understand the advantage (except perhaps some GNU
addicts who have learned and installed all versions of automake anyway).

For the user who just wants to build nail, the new system is not more
complicated than the old one; transition mostly involves passing path
names to make instead of passing them to configure. (It's not even an
argument that the user needs to know the names of Makefile variables;
--prefix didn't work as designed by the GNU folks with the old system
anyway.)

In short, everything is better now.


Building S/MIME and SSL/TLS support using Mozilla NSS
=====================================================

It is possible to build encryption support using Mozilla NSS instead
of OpenSSL. Doing so has both advantages and disadvantages:

- With NSS, nail can use the same key and certificate databases as the
  Mozilla applications (Mozilla Suite, Firefox, Thunderbird). This makes
  it possible to install and configure certificates at one central location.
  Note that running nail and Mozilla at the same time from one certificate
  directory may result in 'Bad database' errors in nail if Mozilla modifies
  the configuration files (nail never modifies them). If you encounter such
  problems, create a copy of the .db files for exclusive use with nail.

- OpenSSL offers more transparent control over certificates. While it is
  possible to modify the NSS databases using command line utilities (see
  <http://www.mozilla.org/projects/security/pki/nss/tools/>), it is
  certainly easier to use PEM files along with descriptions in OpenSSL if
  direct control is desired (e.g. for batch use).

- NSS supports S/MIME in both versions 2 and 3, OpenSSL currently only
  supports version 2.

- Building OpenSSL is much easier than building NSS for use with non-Mozilla
  applications like nail.

To build using NSS, you need both the NSS and the NSPR libraries/include
files from the Mozilla project. If you are using a Linux distribution,
chances are that you can install appropriate RPMs from your vendor, e.g.

mozilla-nss-1.6
mozilla-nss-devel-1.6
mozilla-nspr-devel-1.6
mozilla-nspr-1.6

for Fedora Core Release 2. Note that you can install these without installing
the RPM for the Mozilla main application. Thus it is no problem if you prefer
to use a more recent Mozilla installation in /opt or so. NSS and NSPR are not
updated as often as the Mozilla end-user applications in recent times (but you
should watch for possible future security fixes regardless, of course.)

If you have these RPMs installed, you can uncomment the marked lines in either
the Makefile or in nail.spec. Nail should then build cleanly with NSS support
included, and that's all.

If you want to use NSS without RPMS, you can get binary or source .tar.gz
archives from the Mozilla project pages:

<http://www.mozilla.org/projects/security/pki/nss/>
<http://www.mozilla.org/projects/nspr/>

Or you can use the files from a Mozilla application build directory if you
are building Mozilla Suite, Firefox, Thunderbird etc. from source. Just set
the INCLUDES and LDFLAGS variables appropriately.

If both NSS and OpenSSL are available, NSS is used. This is just because
NSS is normally not found without special action, and thus the build process
simply assumes that you want to build NSS if it manages to build the test
executable.


        Gunnar Ritter                                   9/20/04
