Siemens Version: 1.2 manual

LISE-M EITNER-ALLEE 4 D - 44801 Boc hum TELEFON +49 (0) 234/43 87 02-09 TELE FAX +49 (0) 234/43 87 02-11 E-Mail info@e scrypt.com INTE RN ET www.e scrypt com Security Evaluation of the Siemens Scalance S 612/613 Security Module escrypt GmbH – Embedded Security http://www.escrypt.com Version: 1.2 Date: 19-Aug-05 █ escrypt GmbH GESCHÄFTSFÜHRER:[...]

Index Index 1 Introducti on........................................................................................................ 4 2 Security Se rvices............................................................................................... 6 2.1 Assumptions ..................................................................................[...]

Executive Summary Executive Summary The Scalance S 612/S 613 is a security module to protect the communication between automation networks and to avoid a ttacks to the networks. The security module provides the functionality of a fire wall and a virtual priv ate network (VPN). The system is based on the operating syst em VxWorks and the firewall an[...]

1. Introduction 1 Introduction The Siemens Scalance S 613 is a security module which protects the communication between automat ion networks. It provides authentication, data integrity and confidentiality and protects against data theft and data manipulation. In automation engineering more and more components are being connected. The connection wit[...]

1. Introduction Automation networks demand fo r a variety of security goals such that only basic default-rules are preset. Nonetheless, these default rules provide a secure configuration. The security modules are supposed to be easy to configure and handle, also by non IT-experts. The security module can still be pr ecisely configured according to [...]

2. Security Services 2 Security Services The security module has two Ethernet inte rfaces, one to the internal network which is protected, and the other one to the external network. The interfaces are easily recognizable by a color marker in green an d red color. The processor is an Intel IXP425, it supports AES, SHA-1, MD5, DES and 3DES in hardwar[...]

2. Security Services and 3 on the security module. The packe t filter controls the communication between the internal network and the external network (see Figure 2 ). Figure 2: Firewall function of the security module The firewall offers a packet filter adapt ed from OpenBSD for IP-packets with stateful packet inspection. Another packe t filter fo[...]

2. Security Services Figure 3: VPN-function of the Security -module For the communication over a VPN the se curity modules are collected in groups. For each VPN there is a so called network certificate with corresponding private key that identifies the VPN. Each security module that belongs to the VPN holds a certificate which is signed wit h the p[...]

2. Security Services 2.2.4 Firmware Update The firmware of the security device can be updated. For this purpose, Siemens supplies an encrypted and digitally signed firmware. The user has to authenticate to the security module before loadin g new firmware. The new firmware is transferred to the security module via HTTP s. The signature of the firmwa[...]

2. Security Services 2.3.1 First Initiation At first initialization an IP address is as signed to the Scalance S moduls. After the IP configuration the modules can also be configured over the network. The first user to take the module in operation ent ers a user name and pass word which puts him in the position of administrator. After the security [...]

2. Security Services • Exchange of addresses of the internal networks between security modules • Signalizing that a packet was reject ed because it was not received via an IPsec tunnel. The learning is always initiated if a node wants to communicate with another node and devices located in the same subnet actively scan by ICMP messages. The exc[...]

3. Security Analysis 3 Security Analysis The security module is designed for the use in automation networks. For automation networks availability and robust ness are of first priority since the network must be protected against any failure so that the production never stops. For instance, in the chemical indus try this is extremely important. Of co[...]

3. Security Analysis The implementation of the IKE protocol does not show any known security weaknesses. No known security weak nesses of the OpenBSD-Isakmpd daemon were found. Additionally, the system in corporates a VPN bridge to transport non- IP-packets through the IPsec-tunnel Bro adcast and multicast packets can be transported and also ISO-pr[...]

3. Security Analysis The pf-packet filter of O penBSD does not include any know n weaknesses. A test of the filter rules set by t he configuration tool does not identify any implement ation failures. Also a test of the Layer-2 filt er e2f revealed no security weaknesses. 3.1.3 Firmware Update A new firmware version is provided in an encrypted way a[...]

3. Security Analysis The MiniWeb server is well implemented. The SSL implementation does not show any failures. The only security weakness is the long life span of the certificate and the use of MD5 for the generat ion of the certificates. The key length of 1024 bits is sufficient for the next three to five years. 3.1.6 Time Synchronization and Log[...]

3. Security Analysis 3.2.1 Configuration Files The configuration tool transfers t he configuration data via SSL. Hence, eavesdropping of the connecti on and determination of the data is not possible. The analysis of the configurat ion files gives only information about the default settings of the firewall. The rules defi ned in the configuration fi[...]

4. Summary 4 Summary The security module is designed for using it in an automation network in order to protect the network from data theft and m anipulation as well as attacks from the external network. The reliabili ty of the network is of first priority, the aspect of security follows right after. Furthermore, the device needs to be easy to confi[...]

5. References 5 References Functional Specification, Version 1.0, 7.10.2003 Security Target, Version 0.2, 31.10.2003 Instruction Handbook, 1/2005 Design Specification, 19.1.2004 19-Aug-05 escrypt GmbH 18[...]