aboutsummaryrefslogtreecommitdiff
path: root/docs/technical_references/profiles/tfm_profile_medium.rst
diff options
context:
space:
mode:
Diffstat (limited to 'docs/technical_references/profiles/tfm_profile_medium.rst')
-rw-r--r--docs/technical_references/profiles/tfm_profile_medium.rst477
1 files changed, 0 insertions, 477 deletions
diff --git a/docs/technical_references/profiles/tfm_profile_medium.rst b/docs/technical_references/profiles/tfm_profile_medium.rst
deleted file mode 100644
index b1ab1c1786..0000000000
--- a/docs/technical_references/profiles/tfm_profile_medium.rst
+++ /dev/null
@@ -1,477 +0,0 @@
-########################################
-Trusted Firmware-M Profile Medium Design
-########################################
-
-:Authors: David Hu
-:Organization: Arm Limited
-:Contact: david.hu@arm.com
-
-************
-Introduction
-************
-
-Compared with Profile Small, Profile Medium aims to securely connect devices to
-Cloud services with asymmetric cipher support.
-Profile Medium target devices need more resources for more cipher algorithms
-and higher isolation levels.
-
-For more descriptions and background of TF-M Profile, please refer to Profile
-Small design document [PROFILE-S]_.
-
-**************
-Overall design
-**************
-
-TF-M Profile Medium defines the following feature set:
-
- - Firmware Framework
-
- - Inter-Process Communication (IPC) model [PSA-FF-M]_
- - Isolation level 2 [PSA-FF-M]_
-
- - Internal Trusted Storage (ITS)
-
- - Crypto
-
- - Support both symmetric ciphers and asymmetric ciphers
- - Asymmetric key based cipher suite suggested in TLS/DTLS profiles for
- IoT [RFC7925]_ and CoAP [RFC7252]_, including
-
- - Authenticated Encryption with Associated Data (AEAD) algorithm
- - Asymmetric key algorithm based signature and verification
- - Public-key cryptography based key exchange
- - Hash function
- - HMAC for default Pseudorandom Function (PRF)
-
- - Asymmetric digital signature and verification for Initial Attestation
- Token (IAT)
-
- - Initial Attestation
-
- - Asymmetric key algorithm based Initial Attestation
-
- - Lightweight boot
-
- - Anti-rollback protection
- - Multiple image boot
-
- - Protected Storage (PS) if off-chip storage device is integrated
-
- - Data confidentiality
- - Data integrity
- - Rollback protection
-
-**************
-Design details
-**************
-
-More details of TF-M Profile Medium design are described in following sections.
-
-Firmware framework
-==================
-
-Profile Medium with IPC model and isolation level 2 aims to support usage
-scenarios which require more complicated secure service model and additional
-protection to PSA RoT.
-
-Level 2 isolation
------------------
-
-Profile Medium selects isolation level 2 by default. In addition to isolation
-level 1, the PSA Root of Trust (PSA RoT) is also protected from access by the
-Application Root of Trust (App RoT) in level 2 isolation.
-
-IPC model
----------
-
-Profile Medium enables IPC model by default. IPC model can achieve a more
-flexible framework and higher levels of isolation, but may require more memory
-footprint and bring in longer latency, compared to Library model.
-
-TF-M IPC model implementation follows the PSA Firmware Framework for M
-(PSA-FF-M) [PSA-FF-M]_.
-
-Crypto service
-==============
-
-Compared to Profile Small, Profile Medium includes asymmetric cipher to support
-direct connection to Cloud services via common protocols, such as TLS/DTLS 1.2.
-
-As suggested in CoAP [RFC7252]_ and [RFC7925]_, TF-M Profile Medium by default
-selects ``TLS_ECDHE_ECDSA_WITH_AES_128_CCM`` as reference, which requires:
-
- - ECDHE_ECDSA as key exchange algorithm.
- - AES-128-CCM (AES CCM mode with 128-bit key) as AEAD algorithm.
- Platforms can implement AES-128-CCM with truncated authentication tag to
- achieve less network bandwidth [RFC7925]_.
- - SHA256 as Hash function.
- - HMAC as Message Authentication Code algorithm.
-
-Applications can also support TLS PSK [RFC4279]_ cipher suites, such as
-``TLS_PSK_WITH_AES_128_CCM`` [RFC7925]_.
-
-.. note ::
-
- **Implementation note**
-
- Developers can replace default algorithms with others or implement more
- algorithms according to actual usage scenarios and device capabilities.
-
- If a Crypto hardware accelerator is integrated, the cipher suites and
- algorithms also depend on those accelerator features.
-
-More details of cipher suite are described below.
-
-Digital signature and verification
-----------------------------------
-
-ECDSA is selected by default in Profile Medium.
-ECDSA requires much shorter keys compared with RSA at the same security level.
-Therefore, ECDSA can cost less storage area for assets and less network
-bandwidth to setup a TLS connection.
-ECDSA is also preferred for forward compatibility of future TLS versions.
-
-As requested in [RFC7251]_, ECC curve ``secp256r1`` should be supported. More
-ECC curves can be added based on the requirements in production.
-
-If usage scenarios require RSA algorithm for backward compatibility and legacy
-applications, platforms can add RSA support or replace ECDSA with RSA. The
-cipher suite should be switched accordingly.
-
-AEAD algorithm
---------------
-
-If Protected Storage (PS) is implemented, it is recommended to select the same
-AEAD algorithm for PS service as the one used by TLS/DTLS cipher suite.
-
-Internal Trusted Storage
-========================
-
-The configuration of ITS is the same as those in Profile Small [PROFILE-S]_.
-
-Lightweight boot
-================
-
-BL2 implementation can be device specific. Devices may implement diverse
-boot processes with different features and configurations.
-However, the boot loader must support anti-rollback protection. Boot loader must
-be able to prevent unauthorized rollback, to protect devices from being
-downgraded to earlier versions with known vulnerabilities.
-
-MCUBoot in TF-M is configured as multiple image boot by default in Profile
-Medium. In multiple image boot, secure and non-secure images can be signed
-independently with different keys and they can be updated separately. It can
-support multiple vendors scenarios, in which non-secure and secure images are
-generated and updated by different vendors.
-Multiple image boot may require more storage area compared with single image
-boot.
-
-Protected Storage
-=================
-
-PS service is required if an off-chip storage device is integrated and used on
-the platform.
-
-TF-M PS service relies on an AEAD algorithm to ensure data confidentiality and
-integrity. It is recommended to select the same AEAD algorithm as the one used
-for TLS/DTLS cipher suite.
-
-Anti-rollback protection in PS relies on non-volatile counter(s) provided by
-TF-M Platform Secure Partition (SP).
-
-TF-M audit logging service
-==========================
-
-TF-M audit logging service allows secure services in the system to log critical
-system events and information.
-
-TF-M audit logging service is not enabled in Profile Medium since its IPC model
-dedicated interface is not ready yet.
-
-.. note ::
-
- **Implementation note**
-
- Please note that there is no dedicated PSA specification for Audit Logging
- yet.
- The design, interfaces and implementation of TF-M audit logging service may
- change.
-
-**************
-Implementation
-**************
-
-Overview
-========
-
-The basic idea is to add dedicated profile CMake configuration files under
-folder ``config/profile`` for TF-M Profile Medium default configuration, the
-same as Profile Small does.
-
-The top-level Profile Medium config file collects all the necessary
-configuration flags and set them to default values, to explicitly enable the
-features required in Profile Medium and disable the unnecessary ones, during
-TF-M build.
-
-A platform/use case can provide a configuration extension file to overwrite
-Profile Medium default setting and append other configurations.
-This configuration extension file can be added via parameter
-``TFM_EXTRA_CONFIG_PATH`` in build command line.
-
-The behaviour of the Profile Medium build flow (particularly the order of
-configuration loading and overriding) can be found at
-:ref:`tfm_cmake_configuration`
-
-The details of configurations will be covered in each module in
-`Implementation details`_.
-
-Implementation details
-======================
-
-This section discusses the details of Profile Medium implementation.
-
-Top-level configuration files
------------------------------
-
-The firmware framework configurations in ``config/profile/profile_medium`` are
-shown below.
-
-.. table:: Config flags in Profile Medium top-level CMake config file
- :widths: auto
- :align: center
-
- +--------------------------------------------+-----------------------------------------------------------------------------------------------------+-------------------------------------+
- | Configs | Default value | Descriptions |
- +============================================+=====================================================================================================+=====================================+
- | ``TFM_ISOLATION_LEVEL`` | ``2`` | Select level 2 isolation |
- +--------------------------------------------+-----------------------------------------------------------------------------------------------------+-------------------------------------+
- | ``TFM_PSA_API`` | ``True`` | Select IPC model |
- +--------------------------------------------+-----------------------------------------------------------------------------------------------------+-------------------------------------+
- | ``TFM_PARTITION_INTERNAL_TRUSTED_STORAGE`` | ``ON`` | Enable ITS SP |
- +--------------------------------------------+-----------------------------------------------------------------------------------------------------+-------------------------------------+
- | ``ITS_BUF_SIZE`` | ``32`` | ITS internal transient buffer size |
- +--------------------------------------------+-----------------------------------------------------------------------------------------------------+-------------------------------------+
- | ``TFM_PARTITION_CRYPTO`` | ``ON`` | Enable Crypto service |
- +--------------------------------------------+-----------------------------------------------------------------------------------------------------+-------------------------------------+
- | ``TFM_MBEDCRYPTO_CONFIG_PATH`` | ``${CMAKE_SOURCE_DIR}/lib/ext/mbedcrypto/mbedcrypto_config/tfm_mbedcrypto_config_profile_medium.h`` | Mbed Crypto config file path |
- +--------------------------------------------+-----------------------------------------------------------------------------------------------------+-------------------------------------+
- | ``TFM_PARTITION_INITIAL_ATTESTATION`` | ``ON`` | Enable Initial Attestation service |
- +--------------------------------------------+-----------------------------------------------------------------------------------------------------+-------------------------------------+
- | ``TFM_PARTITION_PROTECTED_STORAGE`` [1]_ | ``ON`` | Enable PS service |
- +--------------------------------------------+-----------------------------------------------------------------------------------------------------+-------------------------------------+
- | ``TFM_PARTITION_PLATFORM`` | ``ON`` | Enable TF-M Platform SP |
- +--------------------------------------------+-----------------------------------------------------------------------------------------------------+-------------------------------------+
- | ``TFM_PARTITION_AUDIT_LOG`` | ``OFF`` | Disable TF-M audit logging service |
- +--------------------------------------------+-----------------------------------------------------------------------------------------------------+-------------------------------------+
-
-.. [1] PS service is enabled by default. Platforms without off-chip storage
- devices can turn off ``TFM_PARTITION_PROTECTED_STORAGE`` to disable PS
- service. See `Protected Storage Secure Partition`_ for details.
-
-.. Note::
-
- Where a configuration is the same as the default in
- ``config/config_default.cmake``, it is omitted from the profile configuration
- file.
-
-Test configuration
-^^^^^^^^^^^^^^^^^^
-
-Standard regression test configuration applies. This means that enabling
-regression testing via
-
-``-DTEST_S=ON -DTEST_NS=ON``
-
-Will enable testing for all enabled partitions. See above for details of enabled
-partitions. Because Profile Medium enables IPC mode, the IPC tests are also
-enabled.
-
-Some cryptography tests are disabled due to the reduced Mbed Crypto config.
-
-.. table:: TFM options in Profile Medium top-level CMake config file
- :widths: auto
- :align: center
-
- +--------------------------------------------+-----------------------------------------------------------------------------------------------------+-------------------------------------+
- | Configs | Default value | Descriptions |
- +============================================+=====================================================================================================+=====================================+
- | ``TFM_CRYPTO_TEST_ALG_CBC`` | ``OFF`` | Test CBC cryptography mode |
- +--------------------------------------------+-----------------------------------------------------------------------------------------------------+-------------------------------------+
- | ``TFM_CRYPTO_TEST_ALG_CCM`` | ``ON`` | Test CCM cryptography mode |
- +--------------------------------------------+-----------------------------------------------------------------------------------------------------+-------------------------------------+
- | ``TFM_CRYPTO_TEST_ALG_CFB`` | ``OFF`` | Test CFB cryptography mode |
- +--------------------------------------------+-----------------------------------------------------------------------------------------------------+-------------------------------------+
- | ``TFM_CRYPTO_TEST_ALG_CTR`` | ``OFF`` | Test CTR cryptography mode |
- +--------------------------------------------+-----------------------------------------------------------------------------------------------------+-------------------------------------+
- | ``TFM_CRYPTO_TEST_ALG_GCM`` | ``OFF`` | Test GCM cryptography mode |
- +--------------------------------------------+-----------------------------------------------------------------------------------------------------+-------------------------------------+
- | ``TFM_CRYPTO_TEST_ALG_SHA_512`` | ``OFF`` | Test SHA-512 cryptography algorithm |
- +--------------------------------------------+-----------------------------------------------------------------------------------------------------+-------------------------------------+
- | ``TFM_CRYPTO_TEST_HKDF`` | ``OFF`` | Test SHA-512 cryptography algorithm |
- +--------------------------------------------+-----------------------------------------------------------------------------------------------------+-------------------------------------+
-
-Device configuration extension
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-To change default configurations and add platform specific configurations,
-a platform can add a platform configuration file at
-``platform/ext<TFM_PLATFORM>/config.cmake``
-
-Crypto service configurations
------------------------------
-
-Crypto Secure Partition
-^^^^^^^^^^^^^^^^^^^^^^^
-
-TF-M Profile Medium enables Crypto SP in top-level CMake config file and selects
-all the Crypto modules.
-
-Mbed Crypto configurations
-^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-TF-M Profile Medium adds a dedicated Mbed Crypto config file
-``tfm_mbedcrypto_config_profile_medium.h`` at
-``/lib/ext/mbedcrypto/mbedcrypto_config``
-file, instead of the common one ``tfm_mbedcrypto_config_default.h`` [CRYPTO-DESIGN]_.
-
-Major Mbed Crypto configurations are set as listed below:
-
- - Enable SHA256
- - Enable generic message digest wrappers
- - Enable AES
- - Enable CCM mode for symmetric ciphers
- - Disable other modes for symmetric ciphers
- - Enable ECDH
- - Enable ECDSA
- - Select ECC curve ``secp256r1``
- - Other configurations required by selected option above
-
-Other configurations can be selected to optimize the memory footprint of Crypto
-module.
-
-A device/use case can append an extra config header to the Profile Medium
-default Mbed Crypto config file. This can be done by setting the
-``TFM_MBEDCRYPTO_PLATFORM_EXTRA_CONFIG_PATH`` cmake variable in the platform
-config file ``platform/ext<TFM_PLATFORM>/config.cmake``. This cmake variable is
-a wrapper around the ``MBEDTLS_USER_CONFIG_FILE`` options, but is preferred as
-it keeps all configuration in cmake.
-
-Internal Trusted Storage configurations
----------------------------------------
-
-ITS service is enabled in top-level Profile Medium CMake config file by default.
-
-The internal transient buffer size ``ITS_BUF_SIZE`` [ITS-INTEGRATE]_ is set to
-32 bytes by default. A platform/use case can overwrite the buffer size in its
-specific configuration extension according to its actual requirement of assets
-and Flash attributes.
-
-Profile Medium CMake config file won't touch the configurations of device
-specific Flash hardware attributes [ITS-INTEGRATE]_.
-
-Protected Storage Secure Partition
-----------------------------------
-
-Data confidentiality, integrity and anti-rollback protection are enabled by
-default in PS.
-
-If PS is selected, AES-CCM is used as AEAD algorithm by default. It requires to
-enable PS implementation to select diverse AEAD algorithm.
-
-If platforms don't integrate any off-chip storage device, platforms can disable
-PS in platform specific configuration extension file via
-``platform/ext<TFM_PLATFORM>/config.cmake``.
-
-BL2 setting
------------
-
-Profile Medium enables MCUBoot provided by TF-M by default. A platform can
-overwrite this configuration by disabling MCUBoot in its configuration extension
-file ``platform/ext<TFM_PLATFORM>/config.cmake``.
-
-If MCUBoot provided by TF-M is enabled, multiple image boot is selected by
-default in TF-M Profile Medium top-level CMake config file.
-
-If a device implements its own boot loader, the configurations are
-implementation defined.
-
-****************
-Platform support
-****************
-
-To enable Profile Medium on a platform, the platform specific CMake file should
-be added into the platform support list in top-level Profile Medium CMake config
-file.
-
-Building Profile Medium
-=======================
-
-To build Profile Medium, argument ``TFM_PROFILE`` in build command line should be
-set to ``profile_medium``.
-
-Take AN521 as an example:
-
-The following commands build Profile Medium without test cases on **AN521** with
-build type **MinSizeRel**, built by **Armclang**.
-
-.. code-block:: bash
-
- cd <TFM root dir>
- mkdir build && cd build
- cmake -DTFM_PLATFORM=mps2/an521 \
- -DTFM_TOOLCHAIN_FILE=../toolchain_ARMCLANG.cmake \
- -DTFM_PROFILE=profile_medium \
- -DCMAKE_BUILD_TYPE=MinSizeRel \
- ../
- cmake --build ./ -- install
-
-The following commands build Profile Medium with regression test cases on
-**AN521** with build type **MinSizeRel**, built by **Armclang**.
-
-.. code-block:: bash
-
- cd <TFM root dir>
- mkdir build && cd build
- cmake -DTFM_PLATFORM=mps2/an521 \
- -DTFM_TOOLCHAIN_FILE=../toolchain_ARMCLANG.cmake \
- -DTFM_PROFILE=profile_medium \
- -DCMAKE_BUILD_TYPE=MinSizeRel \
- -DTEST_S=ON -DTEST_NS=ON \
- ../
- cmake --build ./ -- install
-
-.. Note::
-
- - For devices with more contrained memory and flash requirements, it is
- possible to build with either only TEST_S enabled or only TEST_NS enabled.
- This will decrease the size of the test images. Note that both test suites
- must still be run to ensure correct operation.
-
-More details of building instructions and parameters can be found TF-M build
-instruction guide [TFM-BUILD]_.
-
-*********
-Reference
-*********
-
-.. [PSA-FF-M] `Arm Platform Security Architecture Firmware Framework 1.0 <https://developer.arm.com/-/media/Files/pdf/PlatformSecurityArchitecture/Architect/DEN0063-PSA_Firmware_Framework-1.0.0-2.pdf?revision=2d1429fa-4b5b-461a-a60e-4ef3d8f7f4b4>`_
-
-.. [RFC7925] `Transport Layer Security (TLS) / Datagram Transport Layer Security (DTLS) Profiles for the Internet of Things <https://tools.ietf.org/html/rfc7925>`_
-
-.. [PROFILE-S] :doc:`Trusted Firmware-M Profile Small Design </docs/technical_references/profiles/tfm_profile_small>`
-
-.. [RFC7252] `The Constrained Application Protocol (CoAP) <https://tools.ietf.org/html/rfc7252>`_
-
-.. [RFC4279] `Pre-Shared Key Ciphersuites for Transport Layer Security (TLS) <https://tools.ietf.org/html/rfc4279>`_
-
-.. [RFC7251] `AES-CCM Elliptic Curve Cryptography (ECC) Cipher Suites for TLS <https://tools.ietf.org/html/rfc7251>`_
-
-.. [CRYPTO-DESIGN] :doc:`Crypto design </docs/technical_references/tfm_crypto_design>`
-
-.. [ITS-INTEGRATE] :doc:`ITS integration guide </docs/integration_guide/services/tfm_its_integration_guide>`
-
-.. [TFM-BUILD] :doc:`TF-M build instruction </docs/getting_started/tfm_build_instruction>`
-
---------------
-
-*Copyright (c) 2020-2021, Arm Limited. All rights reserved.*