Add check for NetBSD-style 4-argument skeychallenge() as Gentoo also

has this.  Adapted from a patch from Diego Elio Petteno

configure

@@ -17892,29 +17892,27 @@ if test "${with_skey-'no'}" = "yes"; then
 	blibpath_add="${blibpath_add}:${with_skey}/lib"
     fi
 
-	cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-#include <skey.h>
-_ACEOF
-if ac_fn_c_try_cpp "$LINENO"; then :
+	ac_fn_c_check_header_compile "$LINENO" "skey.h" "ac_cv_header_skey_h" "#include <stdio.h>
+"
+if test "x$ac_cv_header_skey_h" = x""yes; then :
   found=yes
 else
   found=no
 fi
-rm -f conftest.err conftest.$ac_ext
+
+
     else
 	found=no
 	O_CPPFLAGS="$CPPFLAGS"
 	for dir in "" "/usr/local" "/usr/contrib"; do
 	    test -n "$dir" && CPPFLAGS="$O_CPPFLAGS -I${dir}/include"
-	    cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-#include <skey.h>
-_ACEOF
-if ac_fn_c_try_cpp "$LINENO"; then :
+	    ac_fn_c_check_header_compile "$LINENO" "skey.h" "ac_cv_header_skey_h" "#include <stdio.h>
+"
+if test "x$ac_cv_header_skey_h" = x""yes; then :
   found=yes; break
 fi
-rm -f conftest.err conftest.$ac_ext
+
+
 	done
 	if test "$found" = "no" -o -z "$dir"; then
 	    CPPFLAGS="$O_CPPFLAGS"
@@ -18033,6 +18031,38 @@ if test "x$ac_cv_lib_skey_skeyaccess" = x""yes; then :
 
 fi
 
+
+    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for RFC1938-compliant skeychallenge" >&5
+$as_echo_n "checking for RFC1938-compliant skeychallenge... " >&6; }
+    cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+#include <stdio.h>
+	    #include <skey.h>
+int
+main ()
+{
+skeychallenge(NULL, NULL, NULL, 0);
+
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+
+	    $as_echo "#define HAVE_RFC1938_SKEYCHALLENGE 1" >>confdefs.h
+
+	    { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
+$as_echo "yes" >&6; }
+
+else
+
+	    { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+
+
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+
     LDFLAGS="$O_LDFLAGS"
     SUDOERS_LIBS="${SUDOERS_LIBS} -lskey"
     AUTH_OBJS="$AUTH_OBJS rfc1938.lo"
@@ -21369,5 +21399,6 @@ fi
 
 
 
+
 
 

configure.in

@@ -2585,13 +2585,14 @@ if test "${with_skey-'no'}" = "yes"; then
 	CPPFLAGS="${CPPFLAGS} -I${with_skey}/include"
 	SUDO_APPEND_LIBPATH(LDFLAGS, [${with_skey}/lib])
 	SUDO_APPEND_LIBPATH(SUDOERS_LDFLAGS, [${with_skey}/lib])
-	AC_PREPROC_IFELSE([#include <skey.h>], [found=yes], [found=no])
+	AC_CHECK_HEADER([skey.h], [found=yes], [found=no], [#include <stdio.h>])
     else
 	found=no
 	O_CPPFLAGS="$CPPFLAGS"
 	for dir in "" "/usr/local" "/usr/contrib"; do
 	    test -n "$dir" && CPPFLAGS="$O_CPPFLAGS -I${dir}/include"
-	    AC_PREPROC_IFELSE([#include <skey.h>], [found=yes; break])
+	    AC_CHECK_HEADER([skey.h], [found=yes; break], [],
+		[#include <stdio.h>]) 
 	done
 	if test "$found" = "no" -o -z "$dir"; then
 	    CPPFLAGS="$O_CPPFLAGS"
@@ -2605,6 +2606,21 @@ if test "${with_skey-'no'}" = "yes"; then
     fi
     AC_CHECK_LIB(skey, main, [found=yes], [AC_MSG_WARN([Unable to locate libskey.a, you will have to edit the Makefile and add -L/path/to/skey/lib to SUDOERS_LDFLAGS])])
     AC_CHECK_LIB(skey, skeyaccess, AC_DEFINE(HAVE_SKEYACCESS))
+
+    AC_MSG_CHECKING([for RFC1938-compliant skeychallenge])
+    AC_COMPILE_IFELSE(
+	[AC_LANG_PROGRAM(
+	    [[#include <stdio.h>
+	    #include <skey.h>]],
+	    [[skeychallenge(NULL, NULL, NULL, 0);]]
+	)], [
+	    AC_DEFINE(HAVE_RFC1938_SKEYCHALLENGE)
+	    AC_MSG_RESULT([yes])
+	], [
+	    AC_MSG_RESULT([no])
+	]
+    )
+
     LDFLAGS="$O_LDFLAGS"
     SUDOERS_LIBS="${SUDOERS_LIBS} -lskey"
     AUTH_OBJS="$AUTH_OBJS rfc1938.lo"
@@ -3004,6 +3020,7 @@ AH_TEMPLATE(HAVE_SHL_LOAD, [Define to 1 if you have the `shl_load' function.])
 AH_TEMPLATE(HAVE_SIGACTION_T, [Define to 1 if <signal.h> has the sigaction_t typedef.])
 AH_TEMPLATE(HAVE_SKEY, [Define to 1 if you use S/Key.])
 AH_TEMPLATE(HAVE_SKEYACCESS, [Define to 1 if your S/Key library has skeyaccess().])
+AH_TEMPLATE(HAVE_RFC1938_SKEYCHALLENGE, [Define to 1 if the skeychallenge() function is RFC1938-compliant and takes 4 arguments])
 AH_TEMPLATE(HAVE_ST__TIM, [Define to 1 if your struct stat uses an st__tim union])
 AH_TEMPLATE(HAVE_ST_MTIM, [Define to 1 if your struct stat has an st_mtim member])
 AH_TEMPLATE(HAVE_ST_MTIMESPEC, [Define to 1 if your struct stat has an st_mtimespec member])

plugins/sudoers/auth/rfc1938.c

@@ -46,7 +46,7 @@
 #if defined(HAVE_SKEY)
 # include <skey.h>
 # define RFC1938				skey
-#  ifdef __NetBSD__
+#  ifdef HAVE_RFC1938_SKEYCHALLENGE
 #   define rfc1938challenge(a,b,c,d)	skeychallenge((a),(b),(c),(d))
 #  else
 #   define rfc1938challenge(a,b,c,d)	skeychallenge((a),(b),(c))