package/pppd: use uclibc libcrypt instead of openssl

glibc since 2.28 dropped DES encryption routines setkey() and encrypt(),
but uclibc still provides them. So, if building with uclibc, we can
avoid using huge openssl library.

Signed-off-by: Alexander Mukhin <alexander.i.mukhin@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/pppd/Config.in

@@ -3,7 +3,7 @@ config BR2_PACKAGE_PPPD
 	depends on !BR2_STATIC_LIBS
 	depends on !BR2_TOOLCHAIN_USES_MUSL # Use __P() macro all over the tree
 	depends on BR2_USE_MMU
-	select BR2_PACKAGE_OPENSSL
+	select BR2_PACKAGE_OPENSSL if BR2_TOOLCHAIN_USES_GLIBC
 	help
 	  An implementation of the Point-to-point protocol.
 

package/pppd/pppd.mk

@@ -12,10 +12,14 @@ PPPD_LICENSE_FILES = \
 	pppd/tdb.c pppd/plugins/pppoatm/COPYING \
 	pppdump/bsd-comp.c pppd/ccp.c pppd/plugins/passprompt.c
 
-PPPD_DEPENDENCIES = openssl
-PPPD_MAKE_OPTS = \
-	HAVE_INET6=y \
-	OPENSSL_INCLUDE_DIR=$(STAGING_DIR)/usr/include/openssl
+PPPD_MAKE_OPTS = HAVE_INET6=y
+ifeq ($(BR2_TOOLCHAIN_USES_GLIBC),y)
+PPPD_DEPENDENCIES += openssl
+PPPD_MAKE_OPTS += OPENSSL_INCLUDE_DIR=$(STAGING_DIR)/usr/include/openssl
+else
+PPPD_MAKE_OPTS += USE_CRYPT=y
+endif
+
 PPPD_INSTALL_STAGING = YES
 PPPD_TARGET_BINS = chat pppd pppdump pppstats
 PPPD_RADIUS_CONF = \