kobo: add CA certs for https resources

Used the Mozilla CA trust list to validate download site
Fixes issue #871

NEWS.txt

@@ -21,6 +21,8 @@ Version 7.24 - not yet released
   - new default fonts
 * XCVario/Borgelt
   - revert cruise/circling mode change 
+* Kobo
+  - add ca certificates for https downloads
 
 Version 7.23 - 2022/02/10
 * user interface

build/kobo.mk

@@ -82,16 +82,27 @@ THIRDPARTY_TOOL_FILES = $(addprefix $(THIRDPARTY_LIBS_ROOT)/bin/,$(THIRDPARTY_TO
 
 KOBO_KERNEL_DIR = /opt/kobo/kernel
 
+CA_URL = https://curl.se/ca/cacert-2022-04-26.pem
+CA_ALTERNATIVE_URL = $(CA_URL)
+CA_MD5 = aa5ac583708ca35225ac2d230f4acb62
+
+CA_DOWNLOAD = $(DOWNLOAD_DIR)/$(notdir $(CA_URL))
+
+$(CA_DOWNLOAD): | $(DOWNLOAD_DIR)/dirstamp
+	@$(NQ)echo "  GET     $@"
+	$(Q)./build/download.py $(CA_URL) $(CA_ALTERNATIVE_URL) $(CA_MD5) $(DOWNLOAD_DIR)
+
 # /mnt/onboard/.kobo/KoboRoot.tgz is a file that is picked up by
 # /etc/init.d/rcS, extracted to / on each boot; we can use it to
 # install XCSoar
 $(TARGET_OUTPUT_DIR)/KoboRoot.tgz: $(XCSOAR_BIN) \
 	$(KOBO_MENU_BIN) $(KOBO_POWER_OFF_BIN) \
 	$(BITSTREAM_VERA_FILES) \
-	$(topdir)/kobo/inittab $(topdir)/kobo/rcS $(topdir)/kobo/udev.rules
+	$(topdir)/kobo/inittab $(topdir)/kobo/rcS $(topdir)/kobo/udev.rules \
+	$(CA_DOWNLOAD)
 	@$(NQ)echo "  TAR     $@"
 	$(Q)rm -rf $(@D)/KoboRoot
-	$(Q)install -m 0755 -d $(@D)/KoboRoot/etc/udev/rules.d $(@D)/KoboRoot/opt/xcsoar/bin $(@D)/KoboRoot/opt/xcsoar/lib/kernel $(@D)/KoboRoot/opt/xcsoar/share/fonts
+	$(Q)install -m 0755 -d $(@D)/KoboRoot/etc/udev/rules.d $(@D)/KoboRoot/opt/xcsoar/bin $(@D)/KoboRoot/opt/xcsoar/lib/kernel $(@D)/KoboRoot/opt/xcsoar/share/fonts $(@D)/KoboRoot/etc/ssl/certs
 	$(Q)install -m 0755 $(XCSOAR_BIN) $(KOBO_MENU_BIN) $(KOBO_POWER_OFF_BIN) $(topdir)/kobo/rcS $(@D)/KoboRoot/opt/xcsoar/bin
 	$(Q)install -m 0755 --strip --strip-program=$(STRIP) $(THIRDPARTY_TOOL_FILES) $(@D)/KoboRoot/opt/xcsoar/bin
 	$(Q)if test -f $(KOBO_KERNEL_DIR)/uImage.kobo; then install -m 0644 $(KOBO_KERNEL_DIR)/uImage.kobo $(@D)/KoboRoot/opt/xcsoar/lib/kernel; fi
@@ -104,6 +115,7 @@ $(TARGET_OUTPUT_DIR)/KoboRoot.tgz: $(XCSOAR_BIN) \
 	$(Q)install -m 0644 $(topdir)/kobo/inittab $(@D)/KoboRoot/etc
 	$(Q)install -m 0644 $(topdir)/kobo/udev.rules $(@D)/KoboRoot/etc/udev/rules.d/99-xcsoar.rules
 	$(Q)install -m 0644 $(BITSTREAM_VERA_FILES) $(@D)/KoboRoot/opt/xcsoar/share/fonts
+	$(Q)install -T -m 0644 $(CA_DOWNLOAD) $(@D)/KoboRoot/etc/ssl/certs/ca-certificates.crt
 	$(Q)fakeroot tar czfC $@ $(@D)/KoboRoot .
 
 endif