Check tarball checksums after downloading

Makefile

@@ -19,6 +19,7 @@ endif
 WGET := wget -c
 UNTAR := tar -x -f
 UNZIP := unzip
+SHA256 := sha256check() { echo "$$2  $$1" | sha256sum -c; }; sha256check
 
 CROSSTOOL_NG_VERSION := 1.27.0
 RACK_SDK_VERSION := 2.6.3
@@ -39,6 +40,7 @@ toolchain-all: toolchain-lin toolchain-win toolchain-mac cppcheck
 crosstool-ng := $(LOCAL_DIR)/bin/ct-ng
 $(crosstool-ng):
 	$(WGET) "http://crosstool-ng.org/download/crosstool-ng/crosstool-ng-$(CROSSTOOL_NG_VERSION).tar.bz2"
+	$(SHA256) crosstool-ng-$(CROSSTOOL_NG_VERSION).tar.bz2 6307b93a0abdd1b20b85305210094195825ff00a2ed8b650eeab21235088da4b
 	$(UNTAR) crosstool-ng-$(CROSSTOOL_NG_VERSION).tar.bz2
 	rm crosstool-ng-$(CROSSTOOL_NG_VERSION).tar.bz2
 	cd crosstool-ng-$(CROSSTOOL_NG_VERSION) && ./configure --prefix="$(LOCAL_DIR)"
@@ -51,6 +53,7 @@ toolchain-lin := $(LOCAL_DIR)/x86_64-ubuntu16.04-linux-gnu
 toolchain-lin: $(toolchain-lin)
 $(toolchain-lin): $(crosstool-ng)
 	$(WGET) "https://ftp.gnu.org/gnu/texinfo/texinfo-7.2.tar.gz"
+	$(SHA256) texinfo-7.2.tar.gz e86de7dfef6b352aa1bf647de3a6213d1567c70129eccbf8977706d9c91919c8
 	$(UNTAR) texinfo-7.2.tar.gz
 	rm texinfo-7.2.tar.gz
 	cd texinfo-7.2 && ./configure --prefix="$(LOCAL_DIR)"