Chip Card & Security M7791 B12 M7791 B12 M7791 B12 M7791 B12 M7791 B12 M7791 B12 M7791 B12 M7791 B12 M7791 B12 M7791 B12 M7791 B12 M7791 B12 M7791 B12 M7791 B12 M7791 B12 Security Target Lite Version 3.3, 2013-08-06 Author: Steffen Heinkel PUBLIC Author: Steffen Heinkel PUBLIC Edition 2013-08-06 Published by Infineon Technologies AG 81726 Munich, Germany © 2013 Infineon Technologies AG All Rights Reserved. Legal Disclaimer The information given in this document shall in no event be regarded as a guarantee of conditions or characteristics. With respect to any examples or hints given herein, any typical values stated herein and/or any information regarding the application of the device, Infineon Technologies hereby disclaims any and all warranties and liabilities of any kind, including without limitation, warranties of non-infringement of intellectual property rights of any third party. Information For further information on technology, delivery terms and conditions and prices, please contact the nearest Infineon Technologies Office (www.infineon.com). Warnings Due to technical requirements, components may contain dangerous substances. For information on the types in question, please contact the nearest Infineon Technologies Office. Infineon Technologies components may be used in life-support devices or systems only with the express written approval of Infineon Technologies, if a failure of such components can reasonably be expected to cause the failure of that life-support device or system or to affect the safety or effectiveness of that device or system. Life support devices or systems are intended to be implanted in the human body or to support and/or maintain and sustain and/or protect human life. If they fail, it is reasonable to assume that the health of the user or other persons may be endangered. Security Target Lite of M7791 B12 PUBLIC 3 2013-08-06 Revision History Page or Item Subjects (major changes since previous revision) 1.0 Initial Version 3.3 Final Version Trademarks of Infineon Technologies AG used in this document SOLID FLASH™ Miscellaneous The term "Mifare" in this document is only used as an indicator of product compatibility to the corresponding established technology. This applies to the entire document wherever the term is used. Last Trademarks Update 2011-02-24 Security Target Lite of M7791 B12 PUBLIC 4 Content 1 Security Target Introduction (ASE_INT) .........................................................................6 1.1 Security Target and Target of Evaluation Reference ..........................................................6 1.2 Target of Evaluation Overview............................................................................................8 2 Target of Evaluation Description.....................................................................................9 2.1 TOE Definition....................................................................................................................9 2.2 Scope of the TOE.............................................................................................................11 2.2.1 Hardware of the TOE........................................................................................................11 2.2.2 Firmware and Software of the TOE ..................................................................................12 2.2.3 Interfaces of the TOE .......................................................................................................13 2.2.4 Guidance Documentation .................................................................................................13 2.2.5 Forms of Delivery .............................................................................................................13 2.2.6 Production sites................................................................................................................14 2.2.7 TOE Configuration............................................................................................................14 2.2.8 TOE initialization with Customer Software........................................................................16 3 Conformance Claims (ASE_CCL)..................................................................................17 3.1 CC Conformance Claim....................................................................................................17 3.2 PP Claim ..........................................................................................................................17 3.3 Package Claim .................................................................................................................17 3.4 Conformance Rationale....................................................................................................18 3.5 Application Notes .............................................................................................................19 4 Security Problem Definition (ASE_SPD).......................................................................20 4.1 Threats.............................................................................................................................20 4.1.1 Additional Threat due to TOE specific Functionality..........................................................20 4.1.2 Assets regarding the Threats............................................................................................21 4.2 Organizational Security Policies .......................................................................................22 4.2.1 Augmented Organizational Security Policy .......................................................................22 4.3 Assumptions.....................................................................................................................23 4.3.1 Augmented Assumptions..................................................................................................24 5 Security objectives (ASE_OBJ).....................................................................................25 5.1 Security objectives of the TOE .........................................................................................25 5.2 Security Objectives for the development and operational Environment.............................26 5.2.1 Clarification of “Usage of Hardware Platform (OE.Plat-Appl)”...........................................26 5.2.2 Clarification of “Treatment of User Data (OE.Resp-Appl)”.................................................27 5.2.3 Clarification of “Protection during Composite product manufacturing (OE.Process-Sec-IC)” 27 5.3 Security Objectives Rationale...........................................................................................27 6 Extended Component Definition (ASE_ECD) ...............................................................29 6.1 Component “Subset TOE security testing (FPT_TST)” .....................................................29 6.2 Definition of FPT_TST.2 ...................................................................................................29 6.3 TSF self test (FPT_TST)...................................................................................................30 6.4 Family “Generation of Random Numbers (FCS_RNG)” ...................................................30 6.5 Definition of FCS_RNG.1..................................................................................................30 7 Security Requirements (ASE_REQ) ..............................................................................32 Security Target Lite of M7791 B12 PUBLIC 5 7.1 TOE Security Functional Requirements............................................................................32 7.1.1 Extended Components FCS_RNG.1 and FAU_SAS.1 .....................................................33 7.1.2 Subset of TOE testing ......................................................................................................35 7.1.3 Memory access control.....................................................................................................35 7.1.4 Support of Cipher Schemes..............................................................................................39 7.1.5 Data Integrity....................................................................................................................40 7.2 TOE Security Assurance Requirements ...........................................................................42 7.2.1 Refinements .....................................................................................................................43 7.3 Security Requirements Rationale .....................................................................................43 7.3.1 Rationale for the Security Functional Requirements .........................................................43 7.3.2 Rationale of the Assurance Requirements........................................................................47 8 TOE Summary Specification (ASE_TSS) ......................................................................49 8.1 SF_DPM: Device Phase Management .............................................................................49 8.2 SF_PS: Protection against Snooping................................................................................49 8.3 SF_PMA: Protection against Modifying Attacks................................................................49 8.4 SF_PLA: Protection against Logical Attacks.....................................................................49 8.5 SF_CS: Cryptographic Support ........................................................................................49 8.6 Assignment of Security Functional Requirements to TOE’s Security Functionality ...........50 8.7 Security Requirements are internally Consistent ..............................................................51 9 References......................................................................................................................52 9.1 Literature..........................................................................................................................52 10 Appendix: hash signatures of the SCL.........................................................................53 11 List of Abbreviations......................................................................................................54 12 Glossary..........................................................................................................................56 Security Target Lite of M7791 B12 PUBLIC 6 1 Security Target Introduction (ASE_INT) 1.1 Security Target and Target of Evaluation Reference The title of this document is Security Target Lite (ST-Lite). The Security Target comprises the Infineon Technologies SmartCard IC (Security Controller) M7791 B12 with optional SCL v1.01.009 library and with specific IC-dedicated firmware. The target of evaluation (TOE) M7791 B12 is described in the following sections. The Security Target Lite has the revision 3.3 and is dated 2013-08-06. The Target of Evaluation (TOE) is an Infineon smartcard IC (Security Controller) M7791 B12 with optional SCL library version 1.01.009 and with specific IC-dedicated firmware. The versions are listed in Table 1. The Security Target is based on the Protection Profile “Smartcard IC Platform Protection Profile” [1]. The Protection Profile and the Security Target are built in compliance to Common Criteria v3.1. The ST takes into account all relevant current final interpretations. The targeted certificate is EAL5+. Security Target Lite of M7791 B12 PUBLIC 7 Table 1: Identification Version Date Registration Security Target this version see cover page M7791 B12 M7791 B12 with Firmware consisting of STS, RMS, SAM, Mifare compatible software interface and FlashLoader; identifier V77.014.11.2 and optional SW: SCL V1.01.009 and guidance documentation Edition 2012-05 M7791 SOLID FLASHTM Controller for Contactless Transport, Payment and Basic ID Applications Hardware Reference Manual 2012-03 AMM Advanced Mode for Mifare-Compatible Technology Addendum to M7791 Hardware Reference Manual (optional) 2012-06 SLx 70 Family Production and Personalization User's Manual 2013-03 SLE 70 Family Programmer’s Reference User's Manual 2013-08-06 M7791 Security Guidelines User's manual 2013-07 M7790/M7791/M7793/M7794 - Errata Sheet 2013-03 SLE77P Symmetric Crypto Library for µSCP version 2 DES/AES Evaluation based on Protection Profile 1.0 15.06.2007 Security IC Platform Protection Profile PP0035 Version 3.1 Common Criteria for Information Technology Security Evaluation Revision 4 Part 1: Introduction and general model CCMB-2012-09- 001 Part 2: Security functional requirements CCMB-2012-09- 002 Part 3: Security Assurance Components CCMB-2012-09- 003 Common Criteria 2012-Sept Target of Evaluation B12 Guidance Document ation A customer can identify the TOE and its configuration (for details see chapter 2.2.7) using a dedicated signalling sequence during startup in combination with firmware functions. The TOE answers this signalling sequence with a Generic Chip Identification Mode (GCIM). This GCIM outputs a.o. a chip identifier byte, design step, firmware identifier, metal configuration identifier, temperature range and system frequency. The SCL offers a function to extract its version. The identification data and configuration details are described in the confidential Security Target [8] and in the Family Hardware Reference Manual [7]. Security Target Lite of M7791 B12 PUBLIC 8 1.2 Target of Evaluation Overview The TOE comprises the Infineon Technologies SmartCard IC (Security Controller) M7791 B12 with specific IC-dedicated software and optional SCL library. This Security Target (ST) describes the TOE known as the Infineon Technologies AG security controller group as listed in Table 1 and gives a summary product description. The TOE is a member of the Security Controller family SLE70 and meets high requirements in terms of performance and security. The major components of the core system are the CPU, the MMU (Memory Management Unit) and MED (Memory Encryption/Decryption Unit). The TOE implements a 16-MByte linear addressable memory space, a simple scaleable Memory Management concept and a scaleable stack size. The flexible memory concept consists of ROM and SOLID FLASH™ NVM. For the SOLID FLASH™ NVM the Unified Channel Programming (UCP) memory technology is used. The TOE is able to communicate using its contactless interface. The interface provides the flexibility to use different communication protocols: e.g. ISO 14443 Type A and Type B, ISO/IEC 18092 passive mode can be chosen and configured. The RMS library providing some functionality via an API to the Smartcard Embedded Software contains, for example, NVM service routines. The service algorithm provides functionality for the tearing-safe writing to the NVM. The STS firmware is used for test purposes during startup and the Flash Loader allows downloading of user software to NVM during the manufacturing process. The STS resides in a dedicated test ROM area, that is part of the TOE. The routines of the Mifare compatible software interface can be called from the RMS. The µSCP in combination with the optional SCL provides a 3DES and AES implementation and includes countermeasures against SPA, DPA and DFA attacks. The TRNG (True Random Number Generator) is a physical random number generator and meets the requirements of the functionality class PTG.2 of [6]. The TOE can be delivered with or without the SCL library. If the user decides not to use the SCL library, the accompanying “Additional Specific Security Functionality (O.Add-Functions)” Triple Data- Encryption-Standard (3DES) and Advanced Encryption Standard AES are not provided by the TOE. Security Target Lite of M7791 B12 PUBLIC 9 2 Target of Evaluation Description The TOE description helps the reader to understand the specific security environment and the security policy. 2.1 TOE Definition The TOE consists of smartcard ICs (Security Controllers) meeting the highest requirements in terms of performance and security. They are manufactured by Infineon Technologies in a 90 nm CMOS technology. This TOE is intended to be used in smartcards and for its previous use as a development platform for smartcard operating systems according to the lifecycle model from [1] The term Smartcard Embedded Software is used in the following for all operating systems and applications stored and executed on the TOE. The TOE is the platform for the Smartcard Embedded Software. The Smartcard Embedded Software itself is not part of the TOE. Figure 1 shows the block diagram of the M7791: Memories IFX ROM Solid FlashTM NVM RAM Coprocessors µSCP Peripherals 2x timer & WDT CRC RF interface Security Peripherals Voltage Regulator UMSLC Core MMU MED ICO Power Mgmt. IMM Cache Peripheral Bus (16 Bit) Sensors Filters CPU ITP ICU/PEC PRNG TRNG Memory Bus (32 Bit) Figure 1: Block diagram of the TOE The TOE consists of a core system, memories, coprocessor, peripherals, security modules and analog peripherals. The major components of the core system are the CPU, the MMU (Memory Management Unit) and MED (Memory Encryption/Decryption Unit). The µSCP co-processor supports 3DES and AES processing, while the peripheral block contains the random number generation and the external interfaces service. The peripheral block also contains timers and a watchdog. All data of the memory block is encrypted, RAM and ROM are equipped with an error detection code and the NVM is equipped with an error correction code (ECC). Security modules manage the alarms. Alarms may be triggered when the environmental conditions are outside the specified operational range. The CPU accesses memory via the integrated Memory Encryption and Decryption unit (MED). The access rights of the application to the memories can be controlled with the memory management unit Security Target Lite of M7791 B12 PUBLIC 10 (MMU). Errors in RAM and ROM are automatically detected (EDC, Error Detection Code) in terms of the NVM 1-Bit-errors are also corrected (ECC, Error Correction Code). The controller of this TOE stores both code and data in a linear 16-Mbyte memory space, allowing direct access without the need to swap memory segments in and out of memory using a memory management unit. The cache is a high-speed memory buffer located between the CPU and (external) main memories holding a copy of some of the memory contents to enable access. The TRNG (True Random Number Gerenator) is specially designed for smartcard applications. The TRNG fulfils the requirements of the functionality class PTG.2 of [6] and produces genuine random numbers which then can be used directly or as seed for the PRNG (Pseudo Random Number gerenator). The PRNG is not in the scope of the evaluation. The low-power HALT mode is used to reduce the overall power consumption during data transfer between peripherals and volatile memories. The timer can be used to implement timing critical communication protocols. The RF interface is a contactless interface compliant to ISO14443. The Clock Unit (CLKU) supplies the clocks for all components of the TOE. The Clock Unit can work in an internal and external clock mode. When operating in the internal clock mode the system frequency is derived from an internal DCO, whereas in external clock mode, the system clock is derived from an externally applied interface clock. The micro Symmetric Cryptographic Processor (µSCP) supports calculation of dual-key or triple-key triple-DES and AES. The µSCP in combination with the optional SCL compute the complete 3DES and AES algorithm and are designed to counter attacks like DPA, EMA and DFA. Note that the µSCP can be blocked. The blocking depends on the user’s choice prior to the production of the hardware. No accessibility of the µSCP is without impact on any other security policy of the TOE. The STS (self-test software), RMS (Resource Management System), Service Algorithm Minimal (SAM) and Flash Loader together compose the TOE firmware stored in the ROM. All mandatory functions for internal testing, production usage and start-up behavior (STS), and also the RMS and SAM functions are grouped together in a common privilege level. These privilege levels are protected by a hardwired Memory Management Unit (MMU) setting. The user software has to be implemented in NVM. The user can choose, whether the software is loaded into the NVM by Infineon Technologies AG or by the user. The TOE uses Special Function Registers (SFRs). These SFRs are used for general purposes and chip configuration; they are located in NVM in a configuration area page. The bus system comprises two separate bus entities: a memory bus and a peripheral bus for high- speed communication with the peripherals. An intelligent shielding algorithm finishes the upper layers above security critical signals and wires, finally providing the so called “I2 -shield”. The following is a list of features provided by the TOE:  24-bit linear addressing  Up to 16 Mbytes of addressable memory  Extensive set of powerful instructions, including 16- and 32-bit arithmetic and logic instructions  Cache with single-cycle access searching  16-bit ALU Security Target Lite of M7791 B12 PUBLIC 11 2.2 Scope of the TOE The TOE comprises three parts: 1. Hardware of the smartcard security controller 2. Associated firmware and software 3. Documents The hardware configuration options and configuration methods are described in Section 1.1. The second part of this TOE includes the associated firmware and software required for operation and cryptographic support. The documents as described in Section 2.2.4 and listed in Table 1, are supplied for user guidance. In the following description, the term “manufacturer” stands for Infineon Technologies, the manufacturer of the TOE. The Smartcard Embedded Software or user software is not part of the TOE. 2.2.1 Hardware of the TOE The hardware part of the TOE (see Figure 1) as defined in [1] comprises the following: Core System  CPU  Memory Encryption/Decryption Unit (MED)  Memory Management Unit (MMU) Memories  Read-Only Memory (ROM)  Random Access Memory (RAM)  SOLID FLASH™ NVM Peripherals  True Random Number Generator (TRNG)  Pseudo Random Number Generator (PRNG)  Watchdog and timers  Checksum module (CRC)  Radio Frequency Interface (RFI) Control  Dynamic Power Management Security Target Lite of M7791 B12 PUBLIC 12  Internal Clock Oscillator (ICO)  Interrupt and Peripheral Event Channel Controller (ITP and PEC)  Interface Management Module (IMM) Coprocessors  Micro Symmetric Crypto Coprocessor supporting AES and 3DES Standard (optionally blocked) Security Peripherals  Filters  Sensors  User mode Security Life Control (UmSLC)  Voltage regulator Buses  Memory Bus  Peripheral Bus 2.2.2 Firmware and Software of the TOE The entire firmware of the TOE consists of different parts, as described below: One part comprises the RMS and SAM routines for NVM programming, security functional test, and random number online testing (Resource Management System, IC Dedicated Support Software in PP [1]). The RMS and SAM routines are stored by Infineon Technologies in ROM. The second part is the STS, consisting of test and initialization routines (Self Test Software, IC Dedicated Test Software in PP [1]). The STS routines are stored in a specially protected test ROM and are not accessible by user software. The third part is the Flash Loader, a piece of software located in ROM and NVM. It supports download of user software or parts of it to NVM. After completion of the download the Flash Loader can be deactivated permanently by the user. The fourth part is the Mifare compatible software interface, accessible via RMS routines, if the Mifare compatible interface option is active. Note that the Mifare compatible Interface portion is always present but deactivated in case of non-Mifare compatible Interface derivatives. The optional software part of the TOE is the SCL library. The SCL library is used to provide a high level interface to the 3DES and AES cryptography, which is partly implemented on the hardware component µSCP and includes countermeasures against SPA, DPA and DFA attacks. The SCL library is delivered as object code and in this way integrated into the user software. Note: The TOE can be delivered with or without the SCL library. If the user decides not to use the SCL library, the accompanying “Additional Specific Security Functionality (O.Add-Functions)” Triple Security Target Lite of M7791 B12 PUBLIC 13 Data-Encryption-Standard (3DES) and Advanced Encryption Standard AES are not provided by the TOE 2.2.3 Interfaces of the TOE  The physical interface of the TOE to the external environment is the entire surface of the IC.  The RF interface (radio frequency power and signal interface) enables contactless communication between a PICC (proximity integration chip card, PICC) and a PCD reader/writer (proximity coupling device, PCD). Power supply is received and data are received or transmitted by an antenna which consists of a coil with a few turns directly connected to the IC.  The interface to the firmware consists of special registers used for hardware configuration and control (Special Function Registers, SFR).  The interface of the TOE to the operating system is covered by the RMS routines and by the instruction set of the TOE.  The interface of the TOE to the test routines is formed by the STS test routine call, i.e. entry to test mode (STS-TM entry).  The interface to the SCL calculations is defined by the SCL Note that the interfaces of the SCL are optional, as these depend on the procurement order. 2.2.4 Guidance Documentation The guidance documentation consists of:  M7791 SOLID FLASHTM Controller for Contactless Transport, Payment and Basic ID Applications Hardware Reference Manual  AMM Advanced Mode for Mifare-Compatible Technology Addendum to M7791 Hardware Reference Manual (optional). This addendum document describes the AMM (Advanced mode for Mifare-Compatible Technology) and is only provided in case the configuration option AMM is chosen.  SLx 70 Family Production and Personalization User's Manual  SLE 70 Family Programmer’s Reference User’s Manual  M7790/M7791/M7793/M7794 - Errata Sheet These documents contain the description of all interfaces of the software to the hardware relevant for programming the TOE.  M7791 Security Guidelines User's manual: This document provides secure coding guidance to the application writer.  SLE77P Symmetric Crypto Library for µSCP version 2 DES/AES (optional): User Interface, contains all interfaces of the SCL. This document is only delivered to the user in case the SCL is part of the delivered TOE. The “M7790/M7791/M7793/M7794 - Errata Sheet” may be changed during the life cycle of the TOE. Changes are reported in a monthly updated list [5] provided by Infineon Technologies to the user. Finally the certification report may contain an overview of recommendations to a software developer regarding the secure use of the TOE. 2.2.5 Forms of Delivery The TOE can be delivered in the form of complete modules, as plain wafers in an IC case (e.g. DSO20) or in bare dies. The delivery can therefore be at the end of phase 3 or at the end of phase 4 Security Target Lite of M7791 B12 PUBLIC 14 which may also include pre-personalization steps according to [1]. In any case the testing of the TOE is finished and the extended test features are removed. From a security policy point of view the different forms of delivery do not have any impact. The delivery to the software developer (phase 2  phase 1) contains the development package, which is delivered in electronic form. It contains the documents as described above, the development and debugging tools. Part of the software delivery is the Flash Loader program, provided by Infineon Technologies AG, running on the TOE and controlling the download of user software onto the TOE via the RF interface. The download is only possible after successful authentication. The user software can also be downloaded in an encrypted way. In addition, the user can permanently block further use of the Flash Loader. 2.2.6 Production sites The TOE may be handled at different production sites but the silicon is produced in Dresden only. To distinguish the different production sites of various products in the field, the site is coded in the Generic Chip Ident Mode data. The exact coding of the relevant Generic chip identification data is described in [7]. The delivery measures are described in the ALC_DVS aspect. 2.2.7 TOE Configuration This TOE is represented by various configurations called products. The module design, layout and footprint, of all products are identical. However, minor differences between one metal mask allows the TOE to connect to different types of antennas (not part of the TOE). The metal masks differ in their input capacities of the RFI peripheral. The degree of freedom for configuring the TOE is predefined by Infineon Technologies AG. Table 2 shows the TOE hardware configurations such as the maximum configurable memory sizes and availability of cryptographic coprocessors. Security Target Lite of M7791 B12 PUBLIC 15 Table 2: TOE hardware configuration options Module / Feature Values Memories SOLID FLASH™ up to FLASH_MAXSIZEi kBytes RAM for the user up to RAM_MAXSIZEi kBytes Modules µSCP Available/unavailable Interfaces RFI – ISO 14443 generally Available/unavailable RFI Input Capacity CAPA_VALUESi ISO 14443 Type A card mode Available/unavailable ISO 14443 Type B card mode Available/unavailable ISO 14443 Type C card mode (1) Available/unavailable Advanced Communication Mode Available/unavailable Mifare (3) availability Available/unavailable Mifare Hardware support card mode Available/unavailable Advanced Mode for Mifare-Compatible Technology (AMM) Available/unavailable SW support for Mifare compatible 4k cards Available/unavailable SW support for Mifare compatible 1k cards Available/unavailable Direct data transfer (DDT) Available/unavailable Miscellaneous maximum System Frequency 33MHz to HIGHii metal configuration number 0x0 ii) the value for HIGH is defined in [7] i) the values for FLASH_MAXSIZE, RAM_MAXSIZE and CAPA_VALUES are defined in [8] Two methods are available to customers to configure the TOE: 1. To order a configuration, which is defined and offered by Infineon Technologies. Security Target Lite of M7791 B12 PUBLIC 16 2. To apply the Bill-Per-Use (BPU) method for the TOE. This method enables a customer to use tailored products of the TOE within the TOE´s configuration options BPU allows a customer to block chips on demand at the customer´s premises. Customers, who intend to use this feature receive the TOEs in a predefined configuration. The blocking information is part of a chip configuration area. Dedicated blocking information can be modified by customers using specific APDUs. Once final blocking is done, further modifications are disabled. The BPU software part is only present on predefined products, which have been ordered with the BPU option. In all other cases this software is not present on the product. 2.2.8 TOE initialization with Customer Software Several options are available to initialize the TOE with customer software: Table 3: Options to initialize the TOE with customer software 1. The user or/and a subcontractor downloads the software into the NVM. Infineon Technologies does not receive any user software. The Flash Loader can be activated or reactivated by the user or subcontractor to download software into the NVM. 2 The user provides software to download into the NVM to Infineon Technologies AG. The software is loaded into the NVM during chip production. There is no Flash Loader present. 3 The user provides software to download into the NVM to Infineon Technologies AG. The software is loaded into the NVM during chip production. The Flash Loader is blocked by Infineon but can be activated or reactivated by the user or subcontractor to download software into the NVM. The user is required to provide a reactivation procedure as part of the software to Infineon Technologies AG. Security Target Lite of M7791 B12 PUBLIC 17 3 Conformance Claims (ASE_CCL) 3.1 CC Conformance Claim This Security Target (ST) and the TOE claim conformance to Common Criteria version v3.1 part 1 [2], part 2 [3] and part 3 [4]. Conformance of this ST is claimed for: Common Criteria part 2 extended and Common Criteria part 3 conformant. 3.2 PP Claim This Security Target is in strict conformance to the Security IC Platform Protection Profile [1]. The Security IC Platform Protection Profile is registered and certified by the Bundesamt für Sicherheit in der Informationstechnik1 (BSI) under the reference BSI-PP-0035, Version 1.0, dated 15.06.2007. The security assurance requirements of the TOE are according to the Security IC Platform Protection Profile [1]. They are all drawn from Part 3 of the Common Criteria version v3.1. The augmentations of the PP [1] are listed below. Table 4: Augmentations of the assurance level of the TOE Assurance Class Assurance components Description Life-cycle support ALC_DVS.2 Sufficiency of security measures Vulnerability assessment AVA_VAN.5 Advanced methodical vulnerability analysis 3.3 Package Claim The assurance level for the TOE is EAL5 augmented with the components ALC_DVS.2 and AVA_VAN.5. This Security Target does not claim conformance to any additional package of [1]. 1 Bundesamt für Sicherheit in der Informationstechnik (BSI) is the German Federal Authority for Information Security Security Target Lite of M7791 B12 PUBLIC 18 3.4 Conformance Rationale This security target claims strict conformance to [1]. The Target of Evaluation (TOE) is a typical security IC as defined in PP chapter 1.2.2 comprising:  the circuitry of the IC (hardware including the physical memories),  configuration data, initialisation data related to the IC Dedicated Software and the behaviour of the security functionality  the IC Dedicated Software with the parts  the IC Dedicated Test Software,  the IC Dedicated Support Software. The TOE is designed, produced and/or generated by the TOE Manufacturer. Security Problem Definition: Following [1], the security problem definition is enhanced by adding a threat, an organization security policy and an augmented assumption. Including these add-ons, the security problem definition of this security target is consistent with the statement of the security problem definition in [1], as the security target claimed strict conformance to [1]. Conformance Rationale: The augmented organizational security policy P.Add-Functions, coming from the additional security functionality of the cryptographic libraries, the augmented assumption A.Key-Function, related to the usage of key-depending function, and the threat memory access violation T.Mem-Access, due to specific TOE memory access control functionality, have been added. These add-ons have no impact on the conformance statements regarding CC [2] and PP [1], with following rational:  The security target remains conformant to [2], claim 482 as the possibility to introduce additional restrictions is given.  The security target fulfils the strict conformance claim to [1] due to the application notes 5, 6 and 7 which apply here. By those notes the addition of further security functions and security services are covered, even without deriving particular security functionality from a threat but from a policy. Due to additional security functionality, one coming from the cryptographic libraries - O.Add- Functions, and due to the memory access control - O.Mem-Access, additional security objectives have been introduced. These add-ons have no impact on the conformance statements regarding [2] and [1], with following rational:  The security target remains conformant to CC [2], claim 482 as the possibility to introduce additional restrictions is given.  The security target fulfils the strict conformance to [1] due to the application note 9 applying here. This note allows the definition of high-level security goals due to further functions or services provided to the Security IC Embedded Software. Therefore, the security objectives of this security target are consistent with the statement of the security objectives in [1], as the security target claimed strict conformance to [1]. All security functional requirements defined in [1] are included and completely defined in this ST. The security functional requirements listed in the following are all taken from Common Criteria part 2 [3] and additionally included and completely defined in this ST: Security Target Lite of M7791 B12 PUBLIC 19  FDP_ACC.1 “Subset access control”  FDP_ACF.1 “Security attribute based access control”  FMT_MSA.1 “Management of security attributes”  FMT_MSA.3 “Static attribute initialisation”  FMT_SMF.1 “Specification of Management functions”  FCS_COP.1 “Cryptographic support”  FDP_SDI.1 “Stored data integrity monitoring”  FDP_SDI.2 “Stored data integrity monitoring and action” The security functional requirement  FPT_TST.2 “Subset TOE security testing“(Requirement from [3])  FCS_RNG.1 “Random number generation” are included and completely defined in this ST, section 6. All assignments and selections of the security functional requirements are done in [1] and in this security target in section 7.2. The Assurance Requirements of the TOE obtain the Evaluation Assurance Level 5 augmented with the assurance components ALC_DVS.2 and AVA_VAN.5 for the TOE. 3.5 Application Notes The functional requirement FCS_RNG.1 is a refinement of the FCS_RNG.1 defined in the Protection Profile [1] according to “Anwendungshinweise und Interpretationen zum Schema (AIS)” [6]. Security Target Lite of M7791 B12 PUBLIC 20 4 Security Problem Definition (ASE_SPD) The content of [1] applies to this chapter completely. 4.1 Threats The threats are directed against the assets and/or the security functions of the TOE. For example, certain attacks are only one step towards a disclosure of assets while others may directly lead to a compromise of the application security. The more detailed description of specific attacks is given later on in the process of evaluation and certification. An overview on attacks is given in [1] section 3.2. The threats to security are defined and described in [1] section 3.2. Table 5: Threats according [1] T.Phys-Manipulation Physical Manipulation T.Phys-Probing Physical Probing T.Malfunction Malfunction due to Environmental Stress T.Leak-Inherent Inherent Information Leakage T.Leak-Forced Forced Information Leakage T.Abuse-Func Abuse of Functionality T.RND Deficiency of Random Numbers 4.1.1 Additional Threat due to TOE specific Functionality The additional functionality of introducing sophisticated privilege levels and access control allows the secure separation between the operation system(s) and applications, the secure downloading of applications after personalization and enables multitasking by separating memory areas and performing access controls between different applications. Due to this additional functionality “area based memory access control” a new threat is introduced. The Smartcard Embedded Software is responsible for its User Data according to the assumption “Treatment of User Data (A.Resp-Appl)”. However, the Smartcard Embedded Software may comprise different parts, for instance an operating system and one or more applications. In this case, such parts may accidentally or deliberately access data (including code) of other parts, which may result in a security violation. The TOE shall avert the threat “Memory Access Violation (T.Mem-Access)” as specified below. T.Mem-Access Memory Access Violation Parts of the Smartcard Embedded Software may cause security violations by accidentally or deliberately accessing restricted data (which may include code) or privilege levels. Any restrictions are defined by the Security Target Lite of M7791 B12 PUBLIC 21 security policy of the specific application context and must be implemented by the Smartcard Embedded Software. Table 6: Additional threats due to TOE specific functions and augmentations T.Mem-Access Memory Access Violation For details see [1] section 3.2. 4.1.2 Assets regarding the Threats The primary assets concern the User Data which includes the user data as well as program code (Security IC Embedded Software) stored and in operation and the provided security services. These assets have to be protected while being executed and or processed and on the other hand, when the TOE is not in operation. This leads to four primary assets with its related security concerns:  SC1 Integrity of User Data and of the Security IC Embedded Software (while being executed/processed and while being stored in the TOE’s memories),  SC2 Confidentiality of User Data and of the Security IC Embedded Software (while being processed and while being stored in the TOE’s memories)  SC3 Correct operation of the security services provided by the TOE for the Security IC Embedded Software.  SC4 Continuous availability of random numbers SC4 is an additional security service provided by this TOE which is the availability of random numbers. These random numbers are generated either by a true random number or a deterministic random number generator or by both, when a true random number is used as seed for the deterministic random number generator. Note that the generation of random numbers is a requirement of [1]. To be able to protect the listed assets the TOE shall protect its security functionality as well. Therefore critical information about the TOE shall be protected. Critical information includes:  logical design data, physical design data, IC Dedicated Software, and configuration data  Initialisation Data and Pre-personalisation Data, specific development aids, test and characterisation related data, material for software development support, and reticles. The information and material produced and/or processed by the TOE Manufacturer in the TOE development and production environment (Phases 2 up to TOE Delivery) can be grouped as follows:  logical design data,  physical design data,  IC Dedicated Software, Security IC Embedded Software, Initialisation Data and Pre- personalisation Data,  specific development aids,  test and characterisation related data, Security Target Lite of M7791 B12 PUBLIC 22  material for software development support, and  reticles and products in any form as long as they are generated, stored, or processed by the TOE Manufacturer. For details see [1] section 3.1. 4.2 Organizational Security Policies The TOE has to be protected during the first phases of their lifecycle (phases 2 up to TOE delivery which can be after phase 3 or phase 4). Later on each variant of the TOE has to protect itself. The organisational security policy covers this aspect. P.Process-TOE Protection during TOE Development and Production An accurate identification must be established for the TOE. This requires that each instantiation of the TOE carries this unique identification. The organisational security policies are defined and described in [1] section 3.3. Due to the augmentations of [1] an additional policy is introduced and described in the next chapter. Table 7: Organizational Security Policies according to [1] P.Process-TOE Protection during TOE Development and Production 4.2.1 Augmented Organizational Security Policy Due to the augmentations of [1] an additional policy is introduced. The TOE provides specific security functionality, which can be used by the Smartcard Embedded Software. In the following specific security functionality is listed which is not derived from threats identified for the TOE’s environment because it can only be decided in the context of the smartcard application, against which threats the Smartcard Embedded Software will use the specific security functionality. The IC Developer / Manufacturer must apply the policy “Additional Specific Security Functionality (P.Add-Functions)” as specified below. P.Add-Functions Additional Specific Security Functionality The TOE shall provide the following specific security functionality to the Smartcard Embedded Software:  Advanced Encryption Standard (AES)  Triple Data Encryption Standard (3DES) Note 1: The TOE can be delivered with or without the SCL library. If the user decides not to use the SCL library, the accompanying “Additional Specific Security Functionality (O.Add-Functions)” Triple Data- Encryption-Standard (3DES) and Advanced Encryption Standard AES are not provided by the TOE End of note. Security Target Lite of M7791 B12 PUBLIC 23 Note 2: The µSCP can be blocked. The blocking depends on the user’s choice prior to the production of the hardware. No accessibility of the µSCP infers, that Triple Data-Encryption-Standard (3DES) and Advanced Encryption Standard AES are not provided by the TOE. However it is without impact on any other security policy of the TOE; it is exactly equivalent to the situation where the user decides just not to use the µSCP End of note. 4.3 Assumptions The TOE assumptions on the operational environment are defined and described in [1] section 3.4. The assumptions concern the phases where the TOE has left the chip manufacturer. A.Process-Sec-IC Protection during Packaging, Finishing and Personalization It is assumed that security procedures are used after delivery of the TOE by the TOE Manufacturer up to delivery to the end-consumer to maintain confidentiality and integrity of the TOE and of its manufacturing and test data (to prevent any possible copy, modification, retention, theft or unauthorised use). A.Plat-Appl Usage of Hardware Platform The Security IC Embedded Software is designed so that the requirements from the following documents are met: (i) TOE guidance documents (refer to the Common Criteria assurance class AGD) such as the hardware data sheet, and the hardware application notes, and (ii) findings of the TOE evaluation reports relevant for the Security IC Embedded Software as documented in the certification report. A.Resp-Appl Treatment of User Data All User Data are owned by Security IC Embedded Software. Therefore, it must be assumed that security relevant User Data (especially cryptographic keys) are treated by the Security IC Embedded Software as defined for its specific application context. The support of cipher schemas needs to make an additional assumption. Table 8: Assumption according PP [1] A.Process-Sec-IC Protection during Packaging, Finishing and Personalization A.Plat-Appl Usage of Hardware Platform A.Resp-Appl Treatment of User Data Security Target Lite of M7791 B12 PUBLIC 24 4.3.1 Augmented Assumptions The developer of the Smartcard Embedded Software must ensure the appropriate “Usage of Key- dependent Functions (A.Key-Function)” while developing this software in Phase 1 as specified below. A.Key-Function Usage of Key-dependent Functions Key-dependent functions (if any) shall be implemented in the Smartcard Embedded Software in a way that they are not susceptible to leakage attacks (as described under T.Leak-Inherent and T.Leak-Forced). Note that here the routines which may compromise keys when being executed are part of the Smartcard Embedded Software. In contrast to this the threats T.Leak-Inherent and T.Leak-Forced address (i) the cryptographic routines which are part of the TOE For details see [1] section 3.4. Security Target Lite of M7791 B12 PUBLIC 25 5 Security objectives (ASE_OBJ) This section shows the subjects and objects, which are relevant to the TOE. A short overview is given in the following. The user has the following standard high-level security goals related to the assets:  SG1 maintain the integrity of User Data and of the Security IC Embedded Software  SG2 maintain the confidentiality of User Data and of the Security IC Embedded Software  SG3 maintain the correct operation of the security services provided by the TOE for the Security IC Embedded Software  SG4 provision of random numbers. 5.1 Security objectives of the TOE The security objectives of the TOE are defined and described in [1] section 4.1. Table 9: Objectives for the TOE according to [1] O.Phys-Manipulation Protection against Physical Manipulation O.Phys-Probing Protection against Physical Probing O.Malfunction Protection against Malfunction O.Leak-Inherent Protection against Inherent Information Leakage O.Leak-Forced Protection against Forced Information Leakage O.Abuse-Func Protection against Abuse of Functionality O.Identification TOE Identification O.RND Random Numbers The TOE provides “Additional Specific Security Functionality (O.Add-Functions)” as specified below. O.Add-Functions Additional Specific Security Functionality The TOE must provide the following specific security functionality to the Smartcard Embedded Software:  Advanced Encryption Standard (AES)  Triple Data Encryption Standard (3DES), Note 3: The TOE can be delivered with or without the SCL library. If the user decides not to use the SCL library, the accompanying “Additional Specific Security Functionality (O.Add-Functions)” Triple Data- Encryption-Standard (3DES) and Advanced Encryption Standard AES are not provided by the TOE. Security Target Lite of M7791 B12 PUBLIC 26 End of note. Note 4: The µSCP can be blocked. The blocking depends on the user’s choice prior to the production of the hardware. No accessibility of the µSCP infers, that Triple Data-Encryption-Standard (3DES) and Advanced Encryption Standard AES are not provided by the TOE. However it is without impact on any other security policy of the TOE; it is exactly equivalent to the situation where the user decides just not to use the µSCP End of note. The TOE shall provide “Area based Memory Access Control (O.Mem-Access)” as specified below. O.Mem-Access Area based Memory Access Control The TOE must provide the Smartcard Embedded Software with the capability to define restricted access memory areas. The TOE must then enforce the partitioning of such memory areas so that access of software to memory areas and privilege levels is controlled as required, for example, in a multi-application environment. Table 10: Additional objectives due to TOE specific functions and augmentations O.Add-Functions Additional specific security functionality O.Mem-Access Area based Memory Access Control 5.2 Security Objectives for the development and operational Environment The security objectives for the security IC embedded software development environment and the operational environment is defined in [1] section 4.2 and 4.3. The table below lists the security objectives. Table 11: Security objectives for the environment according to [1] Phase 1 OE.Plat-Appl OE.Resp-Appl Usage of Hardware Platform Treatment of User Data Phase 5 – 6 optional Phase 4 OE.Process-Sec-IC Protection during composite product manufacturing 5.2.1 Clarification of “Usage of Hardware Platform (OE.Plat-Appl)” Regarding the cryptographic services this objective of the environment has to be clarified. The TOE supports cipher schemes as additional specific security functionality. If required the Smartcard Embedded Software shall use these cryptographic services of the TOE and their interface as specified. When key-dependent functions implemented in the Smartcard Embedded Software are just being executed, the Smartcard Embedded Software must provide protection against disclosure of confidential data (User Data) stored and/or processed in the TOE by using the methods described under “Inherent Information Leakage (T.Leak-Inherent)” and “Forced Information Leakage (T.Leak- Forced)“. Security Target Lite of M7791 B12 PUBLIC 27 The objectives of the environment regarding the memory, software and firmware protection and the SFR and peripheral-access-rights-handling have to be clarified. For the separation of different applications the Smartcard Embedded Software (Operating System) may implement a memory management scheme based upon security functions of the TOE. 5.2.2 Clarification of “Treatment of User Data (OE.Resp-Appl)” Regarding the cryptographic services this objective of the environment has to be clarified. By definition cipher or plain text data and cryptographic keys are User Data. The Smartcard Embedded Software shall treat these data appropriately, use only proper secret keys (chosen from a large key space) as input for the cryptographic function of the TOE and use keys and functions appropriately in order to ensure the strength of cryptographic operation. This means that keys are treated as confidential as soon as they are generated. The keys must be unique with a very high probability, as well as cryptographically strong. For example, it must be ensured that it is beyond practicality to derive the private key from a public key if asymmetric algorithms are used. If keys are imported into the TOE and/or derived from other keys, quality and confidentiality must be maintained. This implies that appropriate key management has to be realised in the environment. Regarding the memory, software and firmware protection and the SFR and peripheral access rights handling these objectives of the environment has to be clarified. The treatment of User Data is also required when a multi-application operating system is implemented as part of the Smartcard Embedded Software on the TOE. In this case the multi-application operating system should not disclose security relevant user data of one application to another application when it is processed or stored on the TOE. 5.2.3 Clarification of “Protection during Composite product manufacturing (OE.Process-Sec-IC)” The protection during packaging, finishing and personalization includes also the personalization process (Flash Loader software) and the personalization data (TOE software components) during Phase 4, Phase 5 and Phase 6. 5.3 Security Objectives Rationale The security objectives rationale of the TOE are defined and described in [1] section 4.4. For organizational security policy P.Add-Functions, OE.Plat-Appl and OE.Resp-Appl the rationale is given in the following description. Table 12: Security Objective Rational Assumption, Threat or Organisational Security Policy Security Objective P.Add-Functions O.Add-Functions A.Key-Function OE.Plat-Appl OE.Resp-Appl T.Mem-Access O.Mem-Access The justification related to the security objective “Additional Specific Security Functionality (O.Add-Functions)” is as follows: Since O.Add-Functions requires the TOE to implement exactly the Security Target Lite of M7791 B12 PUBLIC 28 same specific security functionality as required by P.Add-Functions; the organisational security policy is covered by the objective. Nevertheless the security objectives O.Leak-Inherent, O.Phys-Probing, O.Malfunction, O.Phys- Manipulation and O.Leak-Forced define how to implement the specific security functionality required by P.Add-Functions. (Note that these objectives support that the specific security functionality is provided in a secure way as expected from P.Add-Functions.) Especially O.Leak-Inherent and O.Leak-Forced refer to the protection of confidential data (User Data or TSF data) in general. User Data are also processed by the specific security functionality required by P.Add-Functions. Compared to [1] clarification has been made for the security objective “Usage of Hardware Platform (OE.Plat-Appl)”: If required the Smartcard Embedded Software shall use these cryptographic services of the TOE and their interface as specified. In addition, the Smartcard Embedded Software must implement functions which perform operations on keys (if any) in such a manner that they do not disclose information about confidential data. The non disclosure due to leakage A.Key-Function attacks is included in this objective OE.Plat-Appl. This addition ensures that the assumption A.Plat-Appl is still covered by the objective OE.Plat-Appl although additional functions are being supported according to O.Add-Functions. Compared to [1] a clarification has been made for the security objective “Treatment of User Data (OE.Resp-Appl)”: By definition cipher or plain text data and cryptographic keys are User Data. So, the Smartcard Embedded Software will protect such data if required and use keys and functions appropriately in order to ensure the strength of cryptographic operation. Quality and confidentiality must be maintained for keys that are imported and/or derived from other keys. This implies that appropriate key management has to be realised in the environment. That is expressed by the assumption A.Key—Function which is covered from OE.Resp–Appl. These measures make sure that the assumption A.Resp-Appl is still covered by the security objective OE.Resp-Appl although additional functions are being supported according to P.Add-Functions. Compared to the PP [1] an enhancement regarding memory area protection has been established. The clear definition of privilege levels for operated software establishes the clear separation of different restricted memory areas for running the firmware, downloading and/or running the operating system and to establish a clear separation between different applications. Nevertheless, it is also possible to define a shared memory section where separated applications may exchange defined data. The privilege levels clearly define by using a hierarchical model the access right from one level to the other. These measures ensure that the threat T.Mem-Access is clearly covered by the security objective O.Mem-Access. The objective O.RND corresponds directly to the description of the threat T.RND. Therefore T.RND is covered by O.RND. The justification of the additional policy and the additional assumption show that they do not contradict to the rationale already given in the Protection Profile for the assumptions, policy and threats defined there. Security Target Lite of M7791 B12 PUBLIC 29 6 Extended Component Definition (ASE_ECD) There are four extended components defined and described for the TOE:  the family FCS_RNG at the class FCS Cryptographic Support  the family FMT_LIM at the class FMT Security Management  the family FAU_SAS at the class FAU Security Audit  the component FPT_TST.2 at the class FPT Protection of the TSF The extended components FMT_LIM and FAU_SAS are defined and described in PP [1] section 5. The components FPT_TST.2 and FCS_RNG.1 are defined in the following sections. 6.1 Component “Subset TOE security testing (FPT_TST)” The security is strongly dependent on the correct operation of the security functions. Therefore, the TOE shall support that particular security functions or mechanisms are tested in the operational phase (Phase 7). The tests can be initiated by the Smartcard Embedded Software and/or by the TOE or is done automatically and continuously. Part 2 of the Common Criteria provides the security functional component “TSF testing (FPT_TST.1)”. The component FPT_TST.1 provides the ability to test the TSF’s correct operation. For the user it is important to know which security functions or mechanisms can be tested. The functional component FPT_TST.1 does not mandate to explicitly specify the security functions being tested. In addition, FPT_TST.1 requires verification of the integrity of TSF data and of the stored TSF executable code which might violate the security policy. Therefore, the functional component ”Subset TOE security testing (FPT_TST.2)” of the family TSF self test has been newly created. This component allows that particular parts of the security mechanisms and functions provided by the TOE are tested. 6.2 Definition of FPT_TST.2 The functional component “Subset TOE security testing (FPT_TST.2)” has been newly created (Common Criteria Part 2 extended). This component allows that particular parts of the security mechanisms and functions provided by the TOE can be tested after TOE Delivery or are tested automatically and continuously during normal operation transparent for the user. This security functional component is used instead of the functional component FPT_TST.1 from Common Criteria Part 2. For the user it is important to know which security functions or mechanisms can be tested. The functional component FPT_TST.1 does not mandate to explicitly specify the security functions being tested. In addition, FPT_TST.1 requires verifying the integrity of TSF data and stored TSF executable code which might violate the security policy. The functional component “Subset TOE testing (FPT_TST.2)” is specified as follows (Common Criteria Part 2 extended). Security Target Lite of M7791 B12 PUBLIC 30 6.3 TSF self test (FPT_TST) Family Behavior The Family Behavior is defined in [3] section 15.14 (438,439). Component levelling FPT_TST TSF self test 1 2 FPT_TST.1: The component FPT_TST.1 is defined in [3] section 15.14 (440, 441,442). FPT_TST.2: Subset TOE security testing, provides the ability to test the correct operation of particular security functions or mechanisms. These tests may be performed at start-up, periodically, at the request of the authorized user, or when other conditions are met. It also provides the ability to verify the integrity of TSF data and executable code. Management: FPT_TST.2 The following actions could be considered for the management functions in FMT:  management of the conditions under which subset TSF self testing occurs, such as during initial start-up, regular interval or under specified conditions  management of the time of the interval appropriate. Audit: FPT_TST.2 There are no auditable events foreseen. FPT_TST.2 Subset TOE testing Hierarchical to: No other components. Dependencies: No dependencies FPT_TST.2.1: The TSF shall run a suite of self tests [selection: during initial start-up, periodically during normal operation, at the request of the authorized user, and/or at the conditions [assignment: conditions under which self test should occur]] to demonstrate the correct operation of [assignment: functions and/or mechanisms]. 6.4 Family “Generation of Random Numbers (FCS_RNG)” The component “Random number generation (FCS_RNG.1)” has to be newly created according the new version of the “Anwendungshinweise und Interpretationen zum Schema (AIS)” [6]. This security functional component is used instead of the functional component FCS_RNG.1 defined in [1]. The family “Generation of random numbers (FCS_RNG)” is specified as follows (Common Criteria Part 2 extended). 6.5 Definition of FCS_RNG.1 This section describes the functional requirements for the generation of random numbers, which Security Target Lite of M7791 B12 PUBLIC 31 may be used as secrets for cryptographic purposes or authentication. The IT security functional requirements for the TOE are defined in an additional family (FCS_RNG) of the Class FCS (Cryptographic support). FCS_RNG Generation of random numbers Family Behaviour This family defines quality requirements for the generation of random numbers that are intended to be used for cryptographic purposes. Component levelling: FCS_RNG: Generation of random numbers TSF self test 1 FCS_RNG.1: Generation of random numbers, requires that the random number generator implements defined security capabilities and that the random numbers meet a defined quality metric. Management: FCS_RNG.1 There are no management activities foreseen. Audit: FCS_RNG.1 There are no actions defined to be auditable. FCS_RNG.1 Random number generation Hierarchical to: No other components. Dependencies: No dependencies. FCS_RNG.1.1: The TSF shall provide a [selection: physical, non-physical true, deterministic, hybrid physical, hybrid deterministic] random number generator that imple- ments: [assignment: list of security capabilities]. FCS_RNG.1.2: The TSF shall provide random numbers that meet [assignment: a defined quality metric]. Application Note 1: The functional requirement FCS_RNG.1 is a refinement of the FCS_RNG.1 defined in the Protection Profile [1] according to “Anwendungshinweise und Interpretationen zum Schema (AIS)” [6]. Security Target Lite of M7791 B12 PUBLIC 32 7 Security Requirements (ASE_REQ) For this section [1] section 6 can be applied completely. 7.1 TOE Security Functional Requirements The security functional requirements (SFR) for the TOE are defined and described in [1] section 6.1 and in the following description. Table 13 provides an overview of the functional security requirements of the TOE, defined in [1] section 6.1. The last column shows, whether the requirement is refined. The refinements are also valid for this ST. Table 13: Security functional requirements defined in PP [1] Security Functional Requirement Refined in PP [1] FRU_FLT.2 “Limited fault tolerance“ Yes FPT_FLS.1 “Failure with preservation of secure state” Yes FMT_LIM.1 “Limited capabilities” No FMT_LIM.2 “Limited availability” No FAU_SAS.1 “Audit storage” No FPT_PHP.3 “Resistance to physical attack” Yes FDP_ITT.1 “Basic internal transfer protection” Yes FPT_ITT.1 “Basic internal TSF data transfer protection Yes FDP_IFC.1 “Subset information flow control” No Table 14 provides an overview about the augmented security functional requirements, which are added to the TOE and defined in this ST. All requirements are taken from [3] Part 2, with the exception of requirement FPT_TST.2 and FCS_RNG.1, which are defined in this ST completely. Table 14: Augmented security functional requirements Security Functional Requirement FPT_TST.2 “Subset TOE security testing“ FDP_ACC.1 “Subset access control” FDP_ACF.1 “Security attribute based access control” FMT_MSA.1 “Management of security attributes” FMT_MSA.3 “Static attribute initialisation” Security Target Lite of M7791 B12 PUBLIC 33 Security Functional Requirement FMT_SMF.1 “Specification of Management functions” FCS_COP.1 “Cryptographic support” FDP_SDI.1 “Stored data integrity monitoring FDP_SDI.2 “Stored data integrity monitoring and action” FCS_RNG.1 “Random number generation” All assignments and selections of the security functional requirements of the TOE are done in [1] and in the following description. The above marked extended components FMT_LIM.1 and FMT_LIM.2 are introduced in [1] to define the IT security functional requirements of the TOE as an additional family (FMT_LIM) of the Class FMT (Security Management). This family describes the functional requirements for the Test Features of the TOE. The new functional requirements were defined in the class FMT because this class addresses the management of functions of the TSF. The additional component FAU_SAS is introduced to define the security functional requirements of the TOE of the Class FAU (Security Audit). This family describes the functional requirements for the storage of audit data and is described in the next chapter. The requirement FPT_TST.2 is the subset of TOE testing and originated in [3]. This requirement is given as the correct operation of the security functions is essential. The TOE provides mechanisms to cover this requirement by the smartcard embedded software and/or by the TOE itself. 7.1.1 Extended Components FCS_RNG.1 and FAU_SAS.1 7.1.1.1 FCS_RNG To define the IT security functional requirements of the TOE an additional family (FCS_RNG) of the Class FCS (cryptographic support) is defined here. This family describes the functional requirements for random number generation used for cryptographic purposes. FCS_RNG.1 Random Number Generation Hierarchical to: No other components Dependencies: No dependencies FCS_RNG.1 Random numbers generation Class PTG.2 according to [6] FCS_RNG.1.1 The TSF shall provide a physical random number generator that implements: PTG.2.1 A total failure test detects a total failure of entropy source immedia- tely when the RNG has started. When a total failure is detected, no random numbers will be output. PTG.2.2 If a total failure of the entropy source occurs while the RNG is being operated, the RNG prevents the output of any internal random num- Security Target Lite of M7791 B12 PUBLIC 34 ber that depends on some raw random numbers that have been gen- erated after the total failure of the entropy source. PTG.2.3 The online test shall detect non-tolerable statistical defects of the raw random number sequence (i) immediately when the RNG has started, and (ii) while the RNG is being operated. The TSF must not output any random numbers before the power-up online test has finished successfully or when a defect has been detected. PTG.2.4 The online test procedure shall be effective to detect non-tolerable weaknesses of the random numbers soon. PTG.2.5 The online test procedure checks the quality of the raw random num- ber sequence. It is triggered continuously. The online test is suitable for detecting non-tolerable statistical defects of the statistical proper- ties of the raw random numbers within an acceptable period of time. FCS_RNG.1.2 The TSF shall provide numbers in the format 8- or 16-bit that meet PTG.2.6 Test procedure A, as defined in [6] does not distinguish the internal random numbers from output sequences of an ideal RNG. PTG.2.7 The average Shannon entropy per internal random bit exceeds 0.997. Application Note 2: The functional requirement FCS_RNG.1 is a refinement of FCS_RNG.1 defined in the Protection Profile [1] according to “Anwendungshinweise und Interpretationen zum Schema (AIS)” [6]. 7.1.1.2 FAU_SAS To define the security functional requirements of the TOE an additional family (FAU_SAS) of the Class FAU (Security Audit) is defined here. This family describes the functional requirements for the storage of audit data. It has a more general approach than FAU_GEN, because it does not necessarily require the data to be generated by the TOE itself and because it does not give specific details of the content of the audit records. The TOE shall meet the requirement “Audit storage (FAU_SAS.1)” as specified below (Common Criteria Part 2 extended). FAU_SAS.1 Audit Storage Hierarchical to: No dependencies Dependencies: No dependencies. FAU_SAS.1.1 The TSF shall provide the test process before TOE Delivery with the capability to store the Initialization Data and/or Pre-personalization Data and/or supplements of the Security IC Embedded Software in the not changeable configuration page area and non-volatile memory. Note, that the TOE can be clearly identified by the Generic Chip Identification Mode (GCIM) and dedicated firmware functions. The GCIM outputs a.o. the chip identification, design step and firmware identifier. Dedicated firmware functions allow a customer to extract the present hardware configuration and the original Chip Identifier Byte, which was valid before blocking. Security Target Lite of M7791 B12 PUBLIC 35 7.1.2 Subset of TOE testing The security is strongly dependent on the correct operation of the security functions. Therefore, the TOE shall support that particular security functions or mechanisms are tested in the operational phase (Phase 7). The tests can be initiated by the Smartcard Embedded Software and/or by the TOE. The TOE shall meet the requirement “Subset TOE testing (FPT_TST.2)” as specified below (Common Criteria Part 2 extended). FPT_TST.2 Subset TOE testing Hierarchical to: No other components. Dependencies: No dependencies FPT_TST.2.1 The TSF shall run a suite of self tests at the request of the authorised user to demonstrate the correct operation of the alarm lines and/or following environmental sensor mechanisms:  CORE – CPU related alarms  Temperature alarm  Memory Bus  NVM_MISS – NVM illegal addressing alarm  FSE – Internal Frequency Sensor alarm  Light – Light sensitive alarm  WDT - Watch Dog Timer related alarms  SW – Software triggered alarm  TRNG – True Random Number Generator  Backside light detection (BLD) - alarm  RAM/ROM EDC or NVM ECC 7.1.3 Memory access control Usage of multiple applications in one Smartcard often requires code and data separation in order to prevent one application from accessing code and/or data of another application. For this reason the TOE provides Area based Memory Access Control. The underlying memory management unit (MMU) is documented in section 4 of [7]. The security service being provided is described in the Security Function Policy (SFP) Memory Access Control Policy. The security functional requirement “Subset access control (FDP_ACC.1)” requires that this policy is in place and defines the scope were it applies. The security functional requirement “Security attribute based access control (FDP_ACF.1)” defines security attribute usage and characteristics of policies. It describes the rules for the function that implements the Security Function Policy (SFP) as identified in FDP_ACC.1. The decision whether an access is permitted or not is taken based upon attributes allocated to the software. The Smartcard Embedded Security Target Lite of M7791 B12 PUBLIC 36 Software defines the attributes and memory areas. The corresponding permission control information is evaluated “on-the-fly” by the hardware so that access is granted/effective or denied/inoperable. The security functional requirement “Static attribute initialisation (FMT_MSA.3)” ensures that the default values of security attributes are appropriately either permissive or restrictive in nature. Alternative values can be specified by any subject provided that the Memory Access Control Policy allows that. This is described by the security functional requirement “Management of security attributes (FMT_MSA.1)”. The attributes are determined during TOE manufacturing (FMT_MSA.3) or set at run-time (FMT_MSA.1). From TOE’s point of view the different roles in the Smartcard Embedded Software can be distinguished according to the memory based access control. However the definition of the roles belongs to the user software. The following Security Function Policy (SFP) Memory Access Control Policy is defined for the requirement “Security attribute based access control (FDP_ACF.1)”: Memory Access Control Policy The TOE shall control read, write, delete and execute accesses of software running at the privilege levels as defined below. Any access is controlled, regardless whether the access is on code or data or a jump on any other privilege level outside the current one. The memory model provides distinct, independent privilege levels separated from each other in the virtual address space. These levels are referred to as the Infineon Technologies (IFX) level, operating system 1 and 2 levels (OS1, OS2), shared application level, and application 1 and 2 levels. A pseudo-level is the “current” level, which is simply the level on which code is currently being executed. The access rights are controlled by the MMU and related to the privilege level as depicted in following diagram: Figure 2: Privilege Levels of the TOE The TOE shall meet the requirement “Subset access control (FDP_ACC.1)” as specified below. Security Target Lite of M7791 B12 PUBLIC 37 FDP_ACC.1 Subset access control Hierarchical to: No other components. Dependencies: FDP_ACF.1 Security attribute based access control FDP_ACC.1.1 The TSF shall enforce the Memory Access Control Policy on all subjects (software running at the defined and assigned privilege levels), all objects (data including code stored in memories) and all the operations defined in the Memory Access Control Policy, i.e. privilege levels. The TOE shall meet the requirement “Security attribute based access control (FDP_ACF.1)” as specified below. FDP_ACF.1 Security attribute based access control Hierarchical to: No other components. Dependencies: FDP_ACC.1 Subset access control FMT_MSA.3 Static attribute initialisation FDP_ACF.1.1 The TSF shall enforce the Memory Access Control Policy to objects based on the following: Subject: - software running at the IFX, OS1 and OS2 privilege levels required to securely operate the chip. This includes also privilege levels running interrupt routines. - software running at the privilege levels containing the application software Object: - data including code stored in memories Attributes: - the memory area where the access is performed to and/or - the operation to be performed. FDP_ACF.1.2 The TSF shall enforce the following rules to determine if an operation among controlled subjects and controlled objects is allowed: evaluate the corresponding permission control information of the relevant memory range before, during or after the access so that accesses to be denied can not be utilised by the subject attempting to perform the operation. FDP_ACF.1.3 The TSF shall explicitly authorize access of subjects to objects based on the following additional rules: none. FDP_ACF.1.4 The TSF shall explicitly deny access of subjects to objects based on the following additional rules: none. The TOE shall meet the requirement “Static attribute initialisation (FMT_MSA.3)” as specified below. FMT_MSA.3 Static attribute initialisation Security Target Lite of M7791 B12 PUBLIC 38 Hierarchical to: No other components. Dependencies: FMT_MSA.1 Management of security attributes FMT_SMR.1 Security roles FMT_MSA.3.1 The TSF shall enforce the Memory Access Control Policy to provide well defined1 default values for security attributes that are used to enforce the SFP. FMT_MSA.3.2 The TSF shall allow any subject, provided that the Memory Access Control Policy is enforced and the necessary access is therefore allowed2 , to specify alternative initial values to override the default values when an object or information is created. The TOE shall meet the requirement “Management of security attributes (FMT_MSA.1)” as specified below: FMT_MSA.1 Management of security attributes Hierarchical to: No other components. Dependencies: [FDP_ACC.1 Subset access control or FDP_IFC.1 Subset information flow control] FMT_SMF.1 Specification of management functions FMT_SMR.1 Security roles FMT_MSA.1.1 The TSF shall enforce the Memory Access Control Policy to restrict the ability to change default, modify or delete the security attributes permission control information to the software running on the privilege levels. The TOE shall meet the requirement “Specification of management functions (FMT_SMF.1)” as specified below: FMT_SMF.1 Specification of management functions Hierarchical to: No other components Dependencies: No dependencies FMT_SMF.1.1 The TSF shall be capable of performing the following security management functions: access the configuration registers of the MMU. 1 The static definition of the access rules is documented in [7] 2 The Smartcard Embedded Software is intended to set the memory access control policy Security Target Lite of M7791 B12 PUBLIC 39 7.1.4 Support of Cipher Schemes The following additional specific security functionality is implemented in the TOE: FCS_COP.1 Cryptographic operation requires a cryptographic operation to be performed in accordance with a specified algorithm and with a cryptographic key of specified sizes. The specified algorithm and cryptographic key sizes can be based on an assigned standard; dependencies are discussed in Section 7.3.1.1. The following additional specific security functionality is implemented in the TOE:  Advanced Encryption Standard (AES)  Triple Data Encryption Standard (3DES) Preface regarding Security Level related to Cryptography The strength of the cryptographic algorithms was not rated in the course of the product certification (see BSIG Section 9, Para.4, Clause 2). But cryptographic functionalities with a security level of 80 bits or lower can no longer be regarded as secure against attacks with high attack potential without considering the application context. Therefore for these functions it shall be checked whether the related cryptographic operations are appropriate for the intended system. Some further hints and guidelines can be derived from the “Technische Richtlinie BSI TR-02102”, www.bsi.bund.de. The cryptographic functionalities 2-key Triple-DES provided by the TOE achieves a security level of maximum 80 Bits (in general context). Triple-DES Operation The 3DES Operation of the TOE shall meet the requirement “Cryptographic operation (FCS_COP.1)” as specified below. FCS_COP.1/3DES Cryptographic operation Hierarchical to: No other components. Dependencies: [FDP_ITC.1 Import of user data without security attributes, or FDP_ITC.2 Import of user data with security attributes, or FCS_CKM.1 Cryptographic key management] FCS_CKM.4 Cryptographic key destruction FCS_COP.1.1/3DES The TSF shall perform encryption and decryption in accordance to a specified cryptographic algorithm Triple Data Encryption Standard (3DES) with cryptographic key sizes of 2 x 56 bit or 3 x 56 bit, that meet the following standards National Institute of Standards and Technology (NIST), Technology Administration, U.S. Department of Data Encryption Standard (DES), NIST Special Publication 800-67, Version 1.1 Note 5: In case the µSCP is blocked or the SCL is not part of the delivery no 3DES computation by hardware is supported. End of Note Security Target Lite of M7791 B12 PUBLIC 40 AES Operation The AES Operation of the TOE shall meet the requirement “Cryptographic operation (FCS_COP.1)” as specified below. FCS_COP.1/AES Cryptographic operation Hierarchical to: No other components. Dependencies: [FDP_ITC.1 Import of user data without security attributes, or FDP_ITC.2 Import of user data with security attributes, or FCS_CKM.1 Cryptographic key generation] FCS_CKM.4 Cryptographic key destruction FCS_COP.1.1/AES The TSF shall perform encryption and decryption in accordance to a specified cryptographic algorithm Advanced Encryption Standard (AES) and cryptographic key sizes of 128 bit or 192 bit or 256 bit that meet the following standards: U.S. Department of Commerce, National Institute of Standards and Technology, Information Technology Laboratory (ITL), Advanced Encryption Standard (AES), FIPS PUB 197 Note 6: In case the µSCP is blocked or the SCL is not part of the delivery no AES computation by hardware is supported. End of note 7.1.5 Data Integrity The TOE shall meet the requirement “Stored data integrity monitoring (FDP_SDI.1)” as specified below: FDP_SDI.1 Stored data integrity monitoring Hierarchical to: No other components Dependencies: No dependencies FDP_SDI.1.1 The TSF shall monitor user data stored in containers controlled by the TSF for inconsistencies between stored data based on the following attributes: EDC value for ROM and RAM smart parity for the cache and ECC value for the NVM and verification of stored data in NVM. The TOE shall meet the requirement “Stored data integrity monitoring and action (FDP_SDI.2)” as specified below: FDP_SDI.2 Stored data integrity monitoring and action Hierarchical to: FDP_SDI.1 stored data integrity monitoring Dependencies: No dependencies FDP_SDI.2.1 The TSF shall monitor user data stored in containers controlled by the TSF for data integrity and one- and/or more-bit-errors on all objects, Security Target Lite of M7791 B12 PUBLIC 41 based on the following attributes: corresponding EDC value for ROM and RAM, smart parity for Cache and error correction ECC for the NVM. FDP_SDI.2.2 Upon detection of a data integrity error, the TSF shall correct 1 bit errors in the NVM automatically and inform the user about other bit errors. Security Target Lite of M7791 B12 PUBLIC 42 7.2 TOE Security Assurance Requirements The evaluation assurance level is EAL5 augmented with ALC_DVS.2 and AVA_VAN.5. In the following table, the security assurance requirements are given. The augmentation of the assurance components compared to [1] is expressed with bold letters. Table 15: Assurance components Aspect Acronym Description Refinement Development ADV_ARC.1 Security Architecture Description [1] ADV_FSP.5 Complete semi-formal functional specification with additional error information [1] ADV_IMP.1 Implementation representation of the TSF [1] ADV_INT.2 Well-structured internals ADV_TDS.4 Semi-formal modular design Guidance Documents AGD_OPE.1 Operational user guidance [1] AGD_PRE.1 Preparative procedures [1] Life-Cycle Support ALC_CMC.4 Production support, acceptance procedures and automation [1] ALC_CMS.5 Development tools CM coverage in ST ALC_DEL.1 Delivery procedures [1] ALC_DVS.2 Identification of security measures [1] ALC_LCD.1 Developer defined life-cycle model ALC_TAT.2 Compliance with implementation standards Security Target Evaluation ASE_CCL.1 Conformance claims ASE_ECD.1 Extended components definition ASE_INT.1 ST introduction ASE_OBJ.2 Security objectives ASE_REQ.2 Derived security requirements Security Target Lite of M7791 B12 PUBLIC 43 ASE_SPD.1 Security problem definition ASE_TSS.1 TOE summary specification Tests ATE_COV.2 Analysis of coverage [1] ATE_DPT.3 Testing: modular design ATE_FUN.1 Functional testing ATE_IND.2 Independent testing - sample Vulnerability Assessment AVA_VAN.5 Advanced methodical vulnerability testing [1] 7.2.1 Refinements Some refinements are taken unchanged from [1] Table 15 provides an overview. 7.3 Security Requirements Rationale 7.3.1 Rationale for the Security Functional Requirements The security functional requirements rationale of the TOE are defined and described in [1] section 6.3 for the following security functional requirements: FDP_ITT.1, FDP_IFC.1, FPT_ITT.1, FPT_PHP.3, FPT_FLS.1, FRU_FLT.2, FMT_LIM.1, FMT_LIM.2, FCS_RNG.1, and FAU_SAS.1. The security functional requirements FPT_TST.2, FDP_ACC.1, FDP_ACF.1, FMT_MSA.1, FMT_MSA.3, FMT_SMF.1, FCS_COP.1, FDP_SDI.1 and FDP_SDI.2 are defined in the following description: Table 16: Rational for additional SFR in the ST Objective TOE Security Functional Requirements O.Add-Functions - FCS_COP.1/3DES „Cryptographic operation“ - FCS_COP.1/AES „Cryptographic operation“ O.Phys-Manipulation - FPT_TST.2 „ Subset TOE security testing “ O.Mem-Access - FDP_ACC.1 “Subset access control” - FDP_ACF.1 “Security attribute based access control” - FMT_MSA.3 “Static attribute initialisation” - FMT_MSA.1 “Management of security attributes” - FMT_SMF.1 “Specification of Management Functions” O.Malfunction - FDP_SDI.1 „Stored data integrity monitoring“ - FDP_SDI.2 „Stored data integrity monitoring and action“ Security Target Lite of M7791 B12 PUBLIC 44 The table above gives an overview, how the security functional requirements are combined to meet the security objectives. The detailed justification is given in the following: The justification related to the security objective “Additional Specific Security Functionality (O.Add-Functions)” is as follows: The security functional requirement(s) “Cryptographic operation (FCS_COP.1)” exactly requires those functions to be implemented which are demanded by O.Add-Functions. Nevertheless, the developer of the Smartcard Embedded Software must ensure that the additional functions are used as specified and that the User Data processed by these functions are protected as defined for the application context. These issues are addressed by the specific security functional requirements:  [FDP_ITC.1 Import of user data without security attributes or FDP_ITC.2 Import of user data with security attributes or FCS_CKM.1 Cryptographic key generation],  FCS_CKM.4 Cryptographic key destruction,  FMT_MSA.2 Secure security attributes. All these requirements have to be fulfilled to support OE.Resp-Appl for FCS_COP.1/3DES (3DES algorithm) and for FCS_COP.1/AES (AES algorithm). The security functional requirements to meet the security objectives O.Leak-Inherent, O.Phys- Probing, O.Malfunction, O.Phys-Manipulation and O.Leak-Forced define how to implement the specific security functionality. However, key-dependent functions could be implemented in the Smartcard Embedded Software. The usage of cryptographic algorithms requires the use of appropriate keys. Otherwise these cryptographic functions do not provide security. The keys have to be unique with a very high probability, and must have a certain cryptographic strength etc. In case of a key import into the TOE (which is usually after TOE delivery) it has to be ensured that quality and confidentiality are maintained. Keys for 3DES and AES are provided by the environment. In this ST the objectives for the environment OE.Plat-Appl and OE.Resp-Appl have been clarified. The Smartcard Embedded Software defines the use of the cryptographic functions FCS_COP.1 provided by the TOE. The requirements for the environment FDP_ITC.1, FDP_ITC.2 and FMT_MSA.2 support an appropriate key management. These security requirements are suitable to meet OE.Resp-Appl. The justification of the security objective and the additional requirements (both for the TOE and its environment) show that they do not contradict the rationale already given in the Protection Profile for the assumptions, policy and threats defined there. The security functional component Subset TOE security testing (FPT_TST.2) has been newly created (Common Criteria Part 2 extended). This component allows that particular parts of the security mechanisms and functions provided by the TOE can be tested after TOE Delivery. This security functional component is used instead of the functional component FPT_TST.1 from Common Criteria Part 2. For the user it is important to know which security functions or mechanisms can be tested. The functional component FPT_TST.1 does not mandate to explicitly specify the security functions being tested. In addition, FPT_TST.1 requires verification of the integrity of TSF data and stored TSF executable code which might violate the security policy. The tested security enforcing functions are SF_PS Protection against Snooping, SF_PMA Protection against Modifying Attacks and SF_CS Cryptographic Support (random numbers). Security Target Lite of M7791 B12 PUBLIC 45 The security functional requirement FPT_TST.2 will detect attempts to conduce a physical manipulation on the monitoring functions of the TOE. The objective of FPT_TST.2 is O.Phys- Manipulation. The physical manipulation will be tried to overcome security enforcing functions. The security functional requirement “Subset access control (FDP_ACC.1)” with the related Security Function Policy (SFP) “Memory Access Control Policy” exactly require the implementation of an area based memory access control as required by O.Mem-Access. The related TOE security functional requirements FDP_ACC.1, FDP_ACF.1, FMT_MSA.3, FMT_MSA.1 and FMT_SMF.1 cover this security objective. The implementation of these functional requirements is represented by the dedicated privilege level concept. The justification of the security objective and the additional requirements show that they do not contradict the rationale already given in [1] for the assumptions, policy and threats defined there. Moreover, these additional security functional requirements cover the requirements by [3] user data protection of chapter 11 which are not refined by [1]. Nevertheless, the developer of the Smartcard Embedded Software must ensure that the additional functions are used as specified and that the User Data processed by these functions are protected as defined for the application context. The TOE only provides the tool to implement the policy defined in the context of the application. The justification related to the security objective “Protection against Malfunction due to Environmental Stress (O.Malfunction)” is as follows: The security functional requirement “Stored data integrity monitoring (FDP_SDI.1)” requires the implementation of an Error Detection (EDC) algorithm which detects integrity errors of the data stored in RAM and ROM. By this the malfunction of the TOE using corrupt data is prevented. Therefore FDP_SDI.1 is suitable to meet the security objective. The security functional requirement “Stored data integrity monitoring and action (FDP_SDI.2)” requires the implementation of an integrity observation and correction which is implemented by the Error Detection (EDC) and Error Correction (ECC) measures. The EDC is present in RAM and ROM of the TOE while the ECC is realized in the NVM. These measures detect and inform about one and more bit errors. In case of the NVM 1 bit errors of the data are corrected automatically. The ECC mechanisms prevent the TOE from using corrupt data. Therefore FDP_SDI.2 is suitable to meet the security objective. The CC part 2 defines the component FIA_SOS.2, which is similar to FCS_RNG.1, as follows: FIA_SOS.2 TSF Generation of secrets Hierarchical to: No other components. Dependencies: No dependencies. FIA_SOS.2.1 The TSF shall provide a mechanism to generate secrets that meet [assignment:a defined quality metric]. FIA_SOS.2.2 The TSF shall be able to enforce the use of TSF generated secrets for [assignment: list of TSF functions]. The CC part 2, annex G.3 [3], states: “This family defines requirements for mechanisms that enforce defined quality metrics on provided secrets, and generate secrets to satisfy the defined metric“. Even the operation in the element FIA_SOS.2.2 allows listing the TSF functions using the generated secrets. Because all applications discussed in annex G.3 are related to authentication, the component FIA_SOS.2 is also intended for authentication purposes while the term “secret” is not limited to authentication data (cf. CC part 2, paragraphs 39-42). Security Target Lite of M7791 B12 PUBLIC 46 Paragraph 685 in the CC part 2 [CCV31_2] recommends use of the component FCS_CKM.1 to address random number generation. However, this may hide the nature of the secrets used for key generation and does not allow describing random number generation for other cryptographic methods (e.g., challenges, padding), authentication (e.g., password seeds), or other purposes (e.g., blinding as a countermeasure against side channel attacks). The component FCS_RNG addresses general RNG, the use of which includes but is not limited to cryptographic mechanisms. FCS_RNG allows to specify requirements for the generation of random numbers including necessary information for the intended use. These details describe the quality of the generated data where other security services rely on. Thus by using FCS_RNG a ST or PP author is able to express a coherent set of SFRs that include or use the generation of random numbers as a security service. 7.3.1.1 Dependencies of Security Functional Requirements The dependencies of security functional requirements are defined and described in [1] section 6.3.2 for the following security functional requirements: FDP_ITT.1, FDP_IFC.1, FPT_ITT.1, FPT_PHP.3, FPT_FLS.1, FRU_FLT.2, FMT_LIM.1, FMT_LIM.2, FCS_RNG.1 and FAU_SAS.1. The dependencies of security functional requirements for the security functional requirements FPT_TST.2, FDP_ACC.1, FDP_ACF.1, FMT_MSA.1, FMT_MSA.3, FMT_SMF.1, FCS_COP.1, FDP_SDI.1 and FDP_SDI.2 are defined in the following description. Table 17: Dependency for cryptographic operation requirement Security Functional Requirement Dependencies Fulfilled by security requirements FCS_COP.1/3DES FCS_CKM.1 Yes, see comment 3 FDP_ITC.1 or FDP_ITC.2 (if not FCS_CKM.1) FCS_CKM.4 Yes, see comment 3 FCS_COP.1/AES FCS_CKM.1 Yes, see comment 3 FDP_ITC.1 or FDP_ITC.2 (if not FCS_CKM.1) FCS_CKM.4 Yes, see comment 3 FPT_TST.2 None see comment 1 FDP_ACC.1 FDP_ACF.1 Yes FDP_ACF.1 FDP_ACC.1 FMT_MSA.3 Yes Yes FMT_MSA.3 FMT_MSA.1 FMT_SMR.1 Yes Not required, see comment 2 FMT_MSA.1 FDP_ACC.1 or FDP_IFC.1 FMT_SMR.1 FMT_SMF.1 Yes see comment 2 Yes FMT_SMF.1 None N/A FDP_SDI.1 None N/A FDP_SDI.2 None N/A Security Target Lite of M7791 B12 PUBLIC 47 Comment 1: The TOE is a platform representing the lowest level in a Smartcard. There is no lower or »underlying abstract machine« used by the TOE which can be tested. Therefore, the former dependency to FPT_AMT.1 is met already and by that dispensable. CC Revision 3 considered this and dropped this dependency. The requirement FPT_TST.2 is satisfied. End of comment. Comment 2: The dependency FMT_SMR.1 introduced by the two components FMT_MSA.1 and FMT_MSA.3 is considered to be satisfied because the access control specified for the intended TOE is not role- based but enforced for each subject. Therefore, there is no need to identify roles in form of a security functional requirement FMT_SMR.1. End of note comment. Comment 3: The security functional requirement “Cryptographic operation (FCS_COP.1)” met by the TOE has the following dependencies: - [FDP_ITC.1 Import of user data without security attributes, or - FDP_ITC.2 Import of user data with security attributes] - FCS_CKM.1 Cryptographic key generation - FCS_CKM.4 Cryptographic key destruction. For the security functional requirement FCS_COP.1/3DES and FCS_COP.1/AES the respective dependencies FCS_CKM.1, FCS_CKM.4 and FDP_ITC.1 or FDP_ITC.2 have to be fulfilled by the environment. That means, that the environment shall meet the requirements FCS_CKM.1 and FCS_CKM.4 as defined in [3], section 10.1 and shall meet the requirements FDP_ITC.1 or FDP_ITC.2 as defined in [3], section 11.7. End of Comment. 7.3.2 Rationale of the Assurance Requirements The chosen assurance level EAL5 and the augmentation with the requirements ALC_DVS.2 and AVA_VAN.5 were chosen in order to meet the assurance expectations explained in the following paragraphs. In Table 15 the different assurance levels are shown as well as the augmentations. The augmentations are in compliance with the [1]. An assurance level EAL5 with the augmentations ALC_DVS.2 and AVA_VAN.5 are required for this type of TOE since it is intended to defend against highly sophisticated attacks without protective environment. This evaluation assurance package was selected to permit a developer to gain maximum assurance from positive security engineering based on good commercial practices. In order to provide a meaningful level of assurance that the TOE provides an adequate level of defence against such attacks, the evaluators should have access to all information regarding the TOE including the TSF internals, the low level design and source code including the testing of the modular design. Additionally the mandatory technical document [11] shall be taken as a basis for the vulnerability analysis of the TOE. Security Target Lite of M7791 B12 PUBLIC 48 ALC_DVS.2 Sufficiency of security measures Development security is concerned with physical, procedural, personnel and other technical measures that may be used in the development environment to protect the TOE. In the particular case of a Security IC the TOE is developed and produced within a complex and distributed industrial process which must especially be protected. Details about the implementation, (e.g. from design, test and development tools as well as Initialization Data) may make such attacks easier. Therefore, in the case of a Security IC, maintaining the confidentiality of the design is very important. This assurance component is a higher hierarchical component to EAL5 (which only requires ALC_DVS.1). ALC_DVS.2 has no dependencies. AVA_VAN.5 Advanced methodical vulnerability analysis Due to the intended use of the TOE, it must be shown to be highly resistant to penetration attacks. This assurance requirement is achieved by AVA_VAN.5. Independent vulnerability analysis is based on highly detailed technical information. The main intent of the evaluator analysis is to determine that the TOE is resistant to penetration attacks performed by an attacker possessing high attack potential. AVA_VAN.5 has dependencies to ADV_ARC.1 “Security architecture description”, ADV_FSP.2 “Security enforcing functional specification”, ADV_TDS.3 “Basic modular design”, ADV_IMP.1 “Implementation representation of the TSF”, AGD_OPE.1 “Operational user guidance”, and AGD_PRE.1 “Preparative procedures”. All these dependencies are satisfied by EAL5. It has to be assumed that attackers with high attack potential try to attack Security ICs like smartcards used for digital signature applications or payment systems. Therefore, specifically AVA_VAN.5 was chosen in order to assure that even these attackers cannot successfully attack the TOE. Security Target Lite of M7791 B12 PUBLIC 49 8 TOE Summary Specification (ASE_TSS) The product overview is given in Section 2.1. The Security Features are described below and the relation to the security functional requirements is shown. The TOE is equipped with the following security features to meet the security functional requirements: Table 18: TOE Security Features SF_DPM Device Phase Management SF_PS Protection against Snooping SF_PMA Protection against Modification Attacks SF_PLA Protection against Logical Attacks SF_CS Cryptographic Support The following description of the security features is a complete representation of the TSF. 8.1 SF_DPM: Device Phase Management The life cycle of the TOE is split up into several phases. Different operation modes help to protect the TOE during each phase of its lifecycle. 8.2 SF_PS: Protection against Snooping The TOE uses various means to protect from snooping of memories and busses and prevents single stepping. 8.3 SF_PMA: Protection against Modifying Attacks This TOE implements protection against modifying attacks of memories, alarm lines and sensors. 8.4 SF_PLA: Protection against Logical Attacks Memory access of the TOE is controlled by a Memory Management Unit (MMU), which implements different priviledge levels. The MMU decides, whether access to a physical memory location is allowed based on the access rights of the privilege levels 8.5 SF_CS: Cryptographic Support The TOE is equipped with a hardware accelerator and an optional software package, which together support symmetric cryptographic operations. It further provides random numbers to meet FCS_RNG.1. Security Target Lite of M7791 B12 PUBLIC 50 8.6 Assignment of Security Functional Requirements to TOE’s Security Functionality The justification and overview of the mapping between security functional requirements (SFR) and the TOE’s security functionality (SF) is given in the sections above. The results are shown in Table 19. The security functional requirements are addressed by at least one related security feature. Table 19: Mapping of SFR and SF SFR SF_DPM SF_PS SF_PMA SF_PLA SF_CS FAU_SAS.1 X FMT_LIM.1 X FMT_LIM.2 X FDP_ACC.1 X X X FDP_ACF.1 X X X FPT_PHP.3 X X X X X FDP_ITT.1 X X X X X FDP_SDI.1 X FDP_SDI.2 X FDP_IFC.1 X X X FMT_MSA.1 X X X FMT_MSA.3 X X X FMT_SMF.1 X X X FRU_FLT.2 X FPT_ITT.1 X X X X FPT_TST.2 X X FPT_FLS.1 X X X X FCS_RNG.1 X FCS_COP.1 /3DES X FCS_COP.1 /AES X Security Target Lite of M7791 B12 PUBLIC 51 8.7 Security Requirements are internally Consistent For this chapter [1] section 6.3.4 can be applied completely. In addition to the discussion of section 6.3 of [1] the security functional requirement FCS_COP.1 is introduced. The security functional requirements required to meet the security objectives O.Leak- Inherent, O.Phys-Probing, O.Malfunction, O.Phys-Manipulation and O.Leak-Forced also protect the cryptographic algorithms implemented according to the security functional requirement FCS_COP.1. Therefore, these security functional requirements support the secure implementation and operation of FCS_COP.1. The functional requirement FPT_TST.2 requires further protection to prevent manipulation of test results, while checking the security functions of the TOE. An attacker could aim to switch off or disturb certain sensors or filters and prevent the detection of distortion by blocking the correct operation of FPT_TST.2. The security functional requirements to meet the security objectives O.Leak-Inherent, O.Phys-Probing, O.Malfunction, O.Phys-Manipulation and O.Leak-Forced also protect the security functional requirement FPT_TST.2. Therefore, the related security functional requirements support the secure implementation and operation of FPT_TST.2. The requirement FPT_TST.2 allows testing of some security mechanisms by the Smartcard Embedded Software after delivery. The implemented privilege level concept represents the area based memory access protection enforced by the MMU. As an attacker could attempt to manipulate the level concept as defined and present in the TOE, the functional requirement FDP_ACC.1 and the related other requirements have to be protected. The security functional requirements necessary to meet the security objectives O.Leak-Inherent, O.Phys-Probing, O.Malfunction, O.Phys-Manipulation and O.Leak-Forced also protect the area based memory access control function implemented according to the security functional requirement described in the security functional requirement FDP_ACC.1 with reference to the Memory Access Control Policy and details given in FDP_ACF.1. Therefore, those security functional requirements support the secure implementation and operation of FDP_ACF.1 with its dependent security functional requirements. The requirement FDP_SDI.2.1 allows detection of integrity errors of data stored in memory. FDP_SDI.2.2 in addition allows correction of one bit errors or taking further action. Both meet the security objective O.Malfunction. The requirements FRU_FLT.2, FPT_FLS.1, and FDP_ACC.1 which also meet this objective are independent from FDP_SDI.2 since they deal with the observation of the correct operation of the TOE and not with the memory content directly. Security Target Lite of M7791 B12 PUBLIC 52 9 References 9.1 Literature [1] Security IC Platform Protection Profile, Version 1.0, 15.06.2007, BSI-PP-0035 [2] Common Criteria for Information Technology Security Evaluation Part 1: Introduction and General Model; Version 3.1 Revision 4 Sept 2012, CCMB-2012-09-001 [3] Common Criteria for Information Technology Security Evaluation Part 2: Security Functional Requirements; Version 3.1 Revision 4 Sept 2012, CCMB-2012-09-002 [4] Common Criteria for Information Technology Security Evaluation Part 3: Security Assurance Requirements; Version 3.1 Revision 4 Sept 2012, CCMB-2012-09-003 [5] Status report, List of all available user guidance [6] Functionality classes and evaluation methodology for physical random number generators AIS31, Version 2.1, 2011-12-02, Bundesamt für Sicherheit in der Informationstechnik. [7] M7791 Controller Family for Payment Application Family Hardware Reference Manual [8] Security Target M7791 [11] Joint Interpretation Library, Application of Attack Potential to Smartcards, Version 2.7, April 2006 [12] M7790 M7793 M7794 M7791 Errata Sheet [13] SLE 70 Family Programmer’s Reference User’s Manual [18] SLx 70 Family Production and Personalization User's Manual Note that the versions of these documents are listed in the certification report. Security Target Lite of M7791 B12 PUBLIC 53 10 Appendix: hash signatures of the SCL Scl77P-uSCP-v2-LIB-base-XSMALL-HUGE.lib: MD5=cf125a71b42099ed2a362ab8360c2884 SHA1=ea7bb8293a3af94037fdc20a97eae2e1fe4272d1 SHA256=4107de6648744266b4d5ce512b1a57c9a0dc6269db316644a40041c6a4fcbcd9 Scl77P-uSCP-v2-LIB-des-XSMALL-HUGE.lib: MD5=52c1ec7ba7e3ca3402512ae0361ac438 SHA1=1d000b17aac566c5ad296f811083ec4b7626f103 SHA256=5375144be53285e2dc3f0e44d1b2c9870f456271f31774974e557eed36ed17e3 Scl77P-uSCP-v2-LIB-aes-XSMALL-HUGE.lib: MD5=0719593879f718f5782cc1ce20dbaa72 SHA1=c08965506f8d964dd516c75e108d6a92ba4ee233 SHA256=c562f9f42569fbb9d3e61683903ebe45be44b124720e5f95a0f3539731daab48 Security Target Lite of M7791 B12 PUBLIC 54 11 List of Abbreviations AES Advanced Encryption Standard AIS31 “Anwendungshinweise und Interpretationen zu ITSEC und CC Funktionalitätsklassen und Evaluationsmethodologie für physikalische Zufallszahlengeneratoren” API Application Programming Interface CC Common Criteria GCIM Generic Chip Identification Mode CPU Central Processing Unit CRC Cyclic Redundancy Check DPA Differential Power Analysis DFA Differential Failure Analysis ECC Error Correction Code EDC Error Detection Code EMA Electro magnetic analysis Flash Flash Memory HW Hardware IC Integrated Circuit ID Identification IMM Interface Management Module ITP Interrupt and Peripheral Event Channel Controller ITSEC Information Technology Security Evaluation Criteria MED Memory Encryption and Decryption MMU Memory Management Unit NVM Non Volatile Memory O Object OS Operating system PEC Peripheral Event Channel PRNG Pseudo Random Number Generator RAM Random Access Memory RMS Resource Management System Security Target Lite of M7791 B12 PUBLIC 55 RNG Random Number Generator ROM Read Only Memory SAM Service Algorithm Minimal µSCP micro Symmetric Cryptographic Processor TSF TOE Security Functionality UM User Mode (STS) UMSLC User mode Security Life Control WDT Watch Dog Timer 3DES Triple DES Encryption Standard Security Target Lite of M7791 B12 PUBLIC 56 12 Glossary Application Program/Data Software which implements the actual TOE functionality provided for the user or the data required for that purpose Central Processing Unit Logic circuitry for digital information processing Chip Identification Data Data to identify the TOE Generic Chip Identification Mode Operational status phase of the TOE, in which actions for identifying the individual chip by transmitting the Chip Identification Data take place Memory Encryption and Decryption Method of encoding/decoding data transfer between CPU and memory Memory Hardware part containing digital information (binary data) Microprocessor CPU with peripherals Object Physical or non-physical part of a system which contains information and is acted upon by subjects Operating System Software which implements the basic TOE actions necessary for operation Programmable Read Only Memory Non-volatile memory which can be written once and then only permits read operations Random Access Memory Volatile memory which permits write and read operations Random Number Generator Hardware part for generating random numbers Read Only Memory Non-volatile memory which permits read operations only Resource Management System Part of the firmware containing NVM programming routines, AIS31 testbench etc. Self Test Software Part of the firmware with routines for controlling the operating state and testing the TOE hardware Security Function Part(s) of the TOE used to implement part(s) of the security objectives Security Target Description of the intended state for countering threats SmartCard Plastic card in credit card format with built-in chip Software Information (non-physical part of the system) which is required to implement functionality in conjunction with the hardware (program code) Subject Entity, generally in the form of a person, who performs actions Security Target Lite of M7791 B12 PUBLIC 57 Target of Evaluation Product or system which is being subjected to an evaluation Test Mode Operational status phase of the TOE in which actions to test the TOE hardware take place Threat Action or event that might prejudice security User Mode Operational status phase of the TOE in which actions intended for the user takes place Infineon Technologies – innovative semiconductor solutions for energy efficiency, mobility and security. Infineon Technologies – innovative semiconductor solutions for energy efficiency, mobility and security. Infineon Technologies – innovative semiconductor solutions for energy efficiency, mobility and security. Infineon Technologies – innovative semiconductor solutions for energy efficiency, mobility and security. Infineon Technologies – innovative semiconductor solutions for energy efficiency, mobility and security. www.infineon.com Published by Infineon Technologies AG