commit 70d1cbafe4ab0176cd9fc01f740e34cd1bae326b
Author: Sebastian Kemper <sebastian_ml@gmx.net>
Date:   Wed Nov 13 20:29:50 2019 +0100

    [gentls_cert] Update message digest
    
    Debian Buster updated /etc/ssl/openssl.cnf to default to
    
    MinProtocol = TLSv1.2
    CipherString = DEFAULT@SECLEVEL=2
    
    gentls_cert currently uses SHA1 as message digest. According to OpenSSL
    documentation this only offers 80 bit of security. 80 bits is enough for
    security level 1, but not 2.
    
    The OpenSSL default MD nowadays is SHA256. This commit updates
    gentls_cert to use it.
    
    Issue was reported on the FS mailing list. The certificates created by
    gentls_cert caused "md too weak" errors and clients were unable to
    connect.
    
    Signed-off-by: Sebastian Kemper <sebastian_ml@gmx.net>

--- a/scripts/gentls_cert.in
+++ b/scripts/gentls_cert.in
@@ -89,7 +89,7 @@ setup_ca() {
 
 	openssl req -out "${CONFDIR}/CA/cacert.pem" \
 		-new -x509 -keyout "${CONFDIR}/CA/cakey.pem" \
-		-config "${TMPFILE}.cfg" -nodes -days ${DAYS} -sha1 >/dev/null || exit 1
+		-config "${TMPFILE}.cfg" -nodes -days ${DAYS} -sha256 >/dev/null || exit 1
 	cat "${CONFDIR}/CA/cacert.pem" > "${CONFDIR}/cafile.pem"
 	cp $TMPFILE.cfg /tmp/ssl.cfg
 	rm "${TMPFILE}.cfg"
@@ -131,11 +131,11 @@ generate_cert() {
 
 	openssl req -new -out "${TMPFILE}.req" \
 		-newkey rsa:${KEY_SIZE} -keyout "${TMPFILE}.key" \
-		-config "${TMPFILE}.cfg" -nodes -sha1 >/dev/null || exit 1
+		-config "${TMPFILE}.cfg" -nodes -sha256 >/dev/null || exit 1
 
 	openssl x509 -req -CAkey "${CONFDIR}/CA/cakey.pem" -CA "${CONFDIR}/CA/cacert.pem" -CAcreateserial \
 		-in "${TMPFILE}.req" -out "${TMPFILE}.crt" -extfile "${TMPFILE}.cfg" \
-		-extensions "${EXTENSIONS}" -days ${DAYS} -sha1 >/dev/null || exit 1
+		-extensions "${EXTENSIONS}" -days ${DAYS} -sha256 >/dev/null || exit 1
 
 	cat "${TMPFILE}.crt" "${TMPFILE}.key" > "${CONFDIR}/${OUTFILE}"