px5g: generate unique serial numbers

Generate a random serial from /dev/urandom when creating selfsigned certs.
Fixes "sec_error_reused_issuer_and_serial" with Firefox.

Signed-off-by: Jo-Philipp Wich <jow@openwrt.org>

SVN-Revision: 43168

package/utils/px5g/Makefile

@@ -1,5 +1,5 @@
 #
-# Copyright (C) 2010 Jo-Philipp Wich <xm@subsignal.org>
+# Copyright (C) 2010-2014 Jo-Philipp Wich <xm@subsignal.org>
 #
 # This is free software, licensed under the GNU General Public License v2.
 # See /LICENSE for more information.
@@ -8,7 +8,7 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=px5g
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 
 PKG_BUILD_DIR := $(BUILD_DIR)/$(PKG_NAME)-$(BUILD_VARIANT)
 PKG_USE_MIPS16:=0

package/utils/px5g/px5g.c

@@ -143,7 +143,7 @@ int selfsigned(char **arg)
 	char *keypath = NULL, *certpath = NULL;
 	bool pem = true;
 	time_t from = time(NULL), to;
-	char fstr[20], tstr[20];
+	char fstr[20], tstr[20], sstr[17];
 	int len;
 
 	while (*arg && **arg == '-') {
@@ -222,8 +222,12 @@ int selfsigned(char **arg)
 	x509write_crt_set_subject_key_identifier(&cert);
 	x509write_crt_set_authority_key_identifier(&cert);
 
+	_urandom(NULL, buf, 8);
+	for (len = 0; len < 8; len++)
+		sprintf(sstr + len*2, "%02x", (unsigned char) buf[len]);
+
 	mpi_init(&serial);
-	mpi_read_string(&serial, 10, "1");
+	mpi_read_string(&serial, 16, sstr);
 	x509write_crt_set_serial(&cert, &serial);
 
 	if (pem) {