* configure.in: New configure option: --with-sha-crypt enabled by

default. Keeping the feature enabled is safe. Disabling it permits
  to disable the references to the SHA256 and SHA512 password
  encryption algorithms from the usage help and manuals (in addition
  to the support for these algorithms in the code).
* libmisc/obscure.c, libmisc/salt.c, src/newusers.c,
  src/chpasswd.c, src/chgpasswd.c, src/passwd.c: ENCRYPT_METHOD is
  always supported in login.defs. Remove the ENCRYPTMETHOD_SELECT
  preprocessor condition.
* libmisc/obscure.c, libmisc/salt.c, src/newusers.c,
  src/chpasswd.c, src/chgpasswd.c, src/passwd.c: Disable SHA256 and
  SHA512 if USE_SHA_CRYPT is not defined (this corresponds to a
  subset of the ENCRYPTMETHOD_SELECT sections).

configure.in

@@ -228,6 +228,14 @@ AC_ARG_WITH(skey,
 AC_ARG_WITH(libcrack,
 	[AC_HELP_STRING([--with-libcrack], [use libcrack @<:@default=yes if found and if PAM not enabled@:>@])],
 	[with_libcrack=$withval], [with_libcrack=no])
+AC_ARG_WITH(sha-crypt,
+	[AC_HELP_STRING([--with-sha-crypt], [allow the SHA256 and SHA512 password encryption algorithms @<:@default=yes@:>@])],
+	[with_sha_crypt=$withval], [with_sha_crypt=yes])
+
+AM_CONDITIONAL(USE_SHA_CRYPT, test "x$with_sha_crypt" = "xyes")
+if test "$with_sha_crypt" = "yes"; then
+		AC_DEFINE(USE_SHA_CRYPT, 1, [Define to allow the SHA256 and SHA512 password encryption algorithms])
+fi
 
 dnl Check for some functions in libc first, only if not found check for
 dnl other libraries.  This should prevent linking libnsl if not really
@@ -378,4 +386,5 @@ echo "	PAM support:			$with_libpam"
 echo "	SELinux support:		$with_selinux"
 echo "	shadow group support:		$enable_shadowgrp"
 echo "	S/Key support:			$with_skey"
+echo "	SHA passwords encryption:	$with_sha_crypt"
 echo