Add notes on shadow passwords

diff --git a/PORTING b/PORTING
index e69dd7560405be33575f8a9d326d1328c5d7e16a..861e0c03ea7e88bd9ea2c120acb97a1dcdc74273 100644 (file)
--- a/PORTING
+++ b/PORTING
@@ -5,7 +5,10 @@ Before trying to port sudo to a new architecture, please join the
 sudo-workers mailing list (see the README file) and ask if anyone
 has a port working or in-progress.  Sudo should be fairly easy to
 port.  Since it uses a configure script, most of the work is often
-done for you.
+done for you.  As long as your operating system is reasonably POSIX
+compliant porting should be easy.  If your operating system has a
+separate library for POSIX compatibility you may need to add it by
+using configure's --with-libraries option.
 
 If your OS is an SVR4 derivative (or some approximation thereof), it may
 be sufficient to tell configure you are runnng SVR4, something like:
@@ -35,7 +38,28 @@ at the Password: prompt).  It is possible that your C library
 contains a broken or unusable crypt() function--try linking with
 -lcrypt if that exists.  Another possibility is that select() is
 not fully functional; running configure with --with-password-timeout=0
-will disable the use of select().
+will disable the use of select().  If sudo prompts you for a
+password but never accepts it, see below.
+
+Sudo detects and recognizes most common shadow password schemes
+automatically.  If you find that sudo is not accepting your password
+and you are sure that it has been typed in correctly there are two
+likely problems.  One possibility is that your C library has a
+broken crypt() function (see above).  The other is that your operating
+system is using shadow passwords and sudo has not detected that
+fact.  Look in config.h to see what, if any, shadow password scheme
+was detected.  The most common are SVR4 (HAVE_GETSPNAM will be
+defined) and SecureWare (HAVE_GETPRPWNAM will be defined).  Check
+the manual pages on your system for "getspnam" and "getprpwnam".
+If one of those exist but the appropriate define does not exist in
+config.h then the problem is most likely that those routines live
+in a library that sudo does not know to link against.  The manual
+page should tell you what library this is.  You can then use the
+--with-libraries option to configure to tell sudo to link with the
+library in question.  For example:
+    --with-libraries='-lgen'
+would cause sudo to link in libgen which contains "getspnam" on SCO
+systems.
 
 If you are trying to port to a system without standard Berkeley
 networking you may find that interfaces.c will not compile.  This