upstream_archive = $(OPK_SOURCE)-$(OPK_SOURCE_VERSION_UPSTREAM).tar.bz2
upstream_url = ftp://ftp.gnupg.org/gcrypt/$(OPK_SOURCE)/$(upstream_archive)
source_archive = ../$(OPK_SOURCE)-$(OPK_SOURCE_VERSION_UPSTREAM).orig.tar.bz2
keys = \
	'D869 2123 C406 5DEA 5E0F  3AB5 249B 39D2 4F25 E3B6' \
	'031E C253 6E58 0D8E A286  A9F2 2071 B08A 33BD 3F06' \
	'46CC 7308 65BB 5C78 EBAB  ADCF 0437 6F3E E085 6959' \
	'5B80 C575 4298 F0CB 55D8  ED6A BCEF 7E29 4B09 2E28'

$(source_archive):
	wget -c '$(upstream_url)'
	set -e; if gpg --version >/dev/null 2>&1; then \
		wget -c '$(upstream_url).sig'; \
		[ -e ../keyring.gpg ] || \
			gpg --no-default-keyring --keyring ../keyring.gpg \
				--keyserver hkp://pool.sks-keyservers.net \
				--recv-keys $(keys) || true; \
		rm -f ../keyring.gpg~; \
		gpg --no-default-keyring --keyring ../keyring.gpg \
			--verify '$(upstream_archive).sig'; \
	fi
	mv '$(upstream_archive)' '$(source_archive)'

source: $(source_archive)