Move file download verification from md5sum to sha256sum

This leaves all the md5sum parts in place for now, but switches
to using sha256sum. Tries both shasum -a 256 and sha256sum.

Change-Id: I393d0dde56521f6e9e76f3d5a8d15c6c830fd683
Reviewed-on: https://gerrit.libreoffice.org/34633Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Norbert Thiebaud <nthiebaud@gmail.com>

Makefile.fetch

@@ -21,9 +21,9 @@ endef
 
 endif
 
-ifneq (,$(MD5SUM))
+ifneq (,$(SHA256SUM))
 define fetch_Download__checksum_command
-&& SUM=`$(MD5SUM) $1 | sed "s/ .*//"` \
+&& SUM=`$(SHA256SUM) $1 | sed "s/ .*//"` \
 && if test "$$SUM" != "$2"; then \
 	echo ERROR: expected checksum for $1 is $2 2>&1 | tee -a $(fetch_LOGFILE); \
 	false; \
@@ -35,7 +35,7 @@ fetch_Download__checksum_command :=
 
 endif
 
-# fetch__Download_item url tarball-name md5sum
+# fetch__Download_item url tarball-name sha256sum
 define fetch__Download_item
 $(if $(wildcard $(TARFILE_LOCATION)/$2),, \
 cd $(TARFILE_LOCATION)/tmp \
@@ -52,7 +52,7 @@ $(filter 32,$(words $(shell echo $(1) | sed -e 's/./& /g')))
 endef
 
 define fetch_Download__subst_var
-$(subst _DLL,_MD5SUM,$(subst _TARBALL,_MD5SUM,$(subst _PACK,_MD5SUM,$(subst _JAR,_MD5SUM,$(1)))))
+$(subst _DLL,_SHA256SUM,$(subst _TARBALL,_SHA256SUM,$(subst _PACK,_SHA256SUM,$(subst _JAR,_SHA256SUM,$(1)))))
 endef
 
 # fetch_Download_item url variable-name

config_host.mk.in

@@ -476,6 +476,7 @@ export SDKDIRNAME=@SDKDIRNAME@
 export SDKDIRNAME_FOR_BUILD=@SDKDIRNAME_FOR_BUILD@
 export SERF_CFLAGS=$(gb_SPACE)@SERF_CFLAGS@
 export SERF_LIBS=$(gb_SPACE)@SERF_LIBS@
+export SHA256SUM=@SHA256SUM@
 export SHOWINCLUDES_PREFIX=@SHOWINCLUDES_PREFIX@
 export SOLARINC=@SOLARINC@
 export SORT=@SORT@

configure.ac

@@ -11853,6 +11853,37 @@ fi
 
 AC_SUBST(MD5SUM)
 
+#
+# check for sha256sum
+#
+SHA256SUM=
+
+for i in shasum /usr/local/bin/shasum /usr/sfw/bin/shasum /opt/sfw/bin/shasum /opt/local/bin/shasum; do
+    eval "$i -a 256 --version" > /dev/null 2>&1
+    ret=$?
+    if test $ret -eq 0; then
+        SHA256SUM="$i -a 256"
+        break
+    fi
+done
+
+if test -z "$SHA256SUM"; then
+    for i in sha256sum /usr/local/bin/sha256sum /usr/sfw/bin/sha256sum /opt/sfw/bin/sha256sum /opt/local/bin/sha256sum; do
+        eval "$i --version" > /dev/null 2>&1
+        ret=$?
+        if test $ret -eq 0; then
+            SHA256SUM=$i
+            break
+        fi
+    done
+fi
+
+if test -z "$SHA256SUM"; then
+    AC_MSG_ERROR([no sha256sum found!])
+fi
+
+AC_SUBST(SHA256SUM)
+
 dnl ===================================================================
 dnl Dealing with l10n options
 dnl ===================================================================