uhttpd: use hexdump -v for the certificate ID

uhttpd.init appends four random bytes as hex digits to the default
organization of its self-signed certificate. Without -v, hexdump prints
"*" instead of repeated lines, and with the format used here each byte
is a line of its own. When adjacent bytes are equal, the organization
gets a "*" instead of the repeated bytes, followed by a newline if more
bytes follow. For example 8b 35 35 ba gives "OpenWrt8b35*", a newline
and "ba". This happens for about 1 in 86 generated certificates.

Pass -v to hexdump, so all four bytes are printed.

Signed-off-by: Josef Schlehofer <pepe.schlehofer@gmail.com>
Link: https://github.com/openwrt/openwrt/pull/25628
Signed-off-by: Robert Marko <robimarko@gmail.com>

package/network/services/uhttpd/Makefile

@@ -5,7 +5,7 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=uhttpd
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 
 PKG_SOURCE_PROTO:=git
 PKG_SOURCE_URL=$(PROJECT_GIT)/project/uhttpd.git

package/network/services/uhttpd/files/uhttpd.init

@@ -50,7 +50,7 @@ generate_keys() {
 	# Prefer px5g for certificate generation (existence evaluated last)
 	local GENKEY_CMD=""
 	local KEY_OPTS="rsa:${bits:-2048}"
-	local UNIQUEID=$(dd if=/dev/urandom bs=1 count=4 | hexdump -e '1/1 "%02x"')
+	local UNIQUEID=$(dd if=/dev/urandom bs=1 count=4 | hexdump -v -e '1/1 "%02x"')
 	[ "$key_type" = "ec" ] && KEY_OPTS="ec -pkeyopt ec_paramgen_curve:${ec_curve:-P-256}"
 	[ -x "$OPENSSL_BIN" ] && GENKEY_CMD="$OPENSSL_BIN req -x509 -sha256 -outform der -nodes"
 	[ -x "$PX5G_BIN" ] && GENKEY_CMD="$PX5G_BIN selfsigned -der"