crypt(3) is used in the plain password file.

In addition, ocpasswd program was added to generate password file entries.

gl/m4/getpass.m4

@@ -0,0 +1,58 @@
+# getpass.m4 serial 14
+dnl Copyright (C) 2002-2003, 2005-2006, 2009-2013 Free Software Foundation,
+dnl Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+# Provide a getpass() function if the system doesn't have it.
+AC_DEFUN([gl_FUNC_GETPASS],
+[
+  dnl Persuade Solaris <unistd.h> and <stdlib.h> to declare getpass().
+  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+
+  AC_CHECK_FUNCS([getpass])
+  AC_CHECK_DECLS_ONCE([getpass])
+  if test $ac_cv_func_getpass = yes; then
+    HAVE_GETPASS=1
+  else
+    HAVE_GETPASS=0
+  fi
+])
+
+# Provide the GNU getpass() implementation. It supports passwords of
+# arbitrary length (not just 8 bytes as on HP-UX).
+AC_DEFUN([gl_FUNC_GETPASS_GNU],
+[
+  dnl Persuade Solaris <unistd.h> and <stdlib.h> to declare getpass().
+  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
+
+  AC_CHECK_DECLS_ONCE([getpass])
+  dnl TODO: Detect when GNU getpass() is already found in glibc.
+  REPLACE_GETPASS=1
+
+  if test $REPLACE_GETPASS = 1; then
+    dnl We must choose a different name for our function, since on ELF systems
+    dnl an unusable getpass() in libc.so would override our getpass() if it is
+    dnl compiled into a shared library.
+    AC_DEFINE([getpass], [gnu_getpass],
+      [Define to a replacement function name for getpass().])
+  fi
+])
+
+# Prerequisites of lib/getpass.c.
+AC_DEFUN([gl_PREREQ_GETPASS], [
+  AC_CHECK_HEADERS_ONCE([stdio_ext.h termios.h])
+  AC_CHECK_FUNCS_ONCE([__fsetlocking tcgetattr tcsetattr])
+  AC_CHECK_DECLS([__fsetlocking],,,
+    [[#include <stdio.h>
+      #if HAVE_STDIO_EXT_H
+       #include <stdio_ext.h>
+      #endif]])
+  AC_CHECK_DECLS_ONCE([fflush_unlocked])
+  AC_CHECK_DECLS_ONCE([flockfile])
+  AC_CHECK_DECLS_ONCE([fputs_unlocked])
+  AC_CHECK_DECLS_ONCE([funlockfile])
+  AC_CHECK_DECLS_ONCE([putc_unlocked])
+  :
+])