wolfTPM (TPM 2.0)

Portable TPM 2.0 project designed for embedded use.

Project Features

This implementation provides all TPM 2.0 API's in compliance with the specification.
Wrappers provided to simplify Key Generation/Loading, RSA encrypt/decrypt, ECC sign/verify, ECDH, NV, Hashing/HACM, AES, Sealing/Unsealing, Attestation, PCR Extend/Quote and Secure Root of Trust.
Testing done using TPM 2.0 modules from STMicro ST33 (SPI/I2C), Infineon OPTIGA SLB9670/SLB9672/SLB9673, Microchip ATTPM20, Nations Tech Z32H330TC/NS350 and Nuvoton NPCT650/NPCT750.
wolfTPM uses the TPM Interface Specification (TIS) to communicate either over SPI, or using a memory mapped I/O range.
On Linux, wolfTPM auto-detects between the kernel TPM driver (/dev/tpmX) and direct SPI access at runtime — a simple ./configure && make works with either interface.
wolfTPM can also use the Linux TPM kernel interface (/dev/tpmX) to talk with any physical TPM on SPI, I2C and even LPC bus.
Platform support for Raspberry Pi (Linux), MMIO, STM32 with CubeMX, Atmel ASF, Xilinx, QNX Infineon TriCore and Barebox.
The design allows for easy portability to different platforms:
- Native C code designed for embedded use.
- Single IO callback for hardware SPI interface.
- No external dependencies.
- Compact code size and minimal memory use.
Includes example code for:
- Most TPM2 native API's
- All TPM2 wrapper API's
- PKCS 7
- Certificate Signing Request (CSR)
- TLS Client
- TLS Server
- Use of the TPM's Non-volatile memory
- Attestation (activate and make credential)
- Benchmarking TPM algorithms and TLS
- Key Generation (primary, RSA/ECC and symmetric), loading and storing to flash (NV memory)
- Sealing and Unsealing data with an RSA key or externally signed policy.
- Time signed or set
- PCR read/reset
- GPIO configure, read and write.
- Endorsement Key/Cert retrieval and validation.
Parameter encryption support using AES-CFB or XOR.
Support for salted unbound authenticated sessions.
Support for HMAC Sessions.
Support for reading Endorsement certificates (EK Credential Profile).

Note: See examples/README.md for details on using the examples.

TPM 2.0 Overview

Hierarchies

Platform    TPM_RH_PLATFORM
Owner       TPM_RH_OWNER
Endorsement TPM_RH_ENDORSEMENT

Each hierarchy has their own manufacture generated seed.

The arguments used on TPM2_Create or TPM2_CreatePrimary create a template, which is fed into a KDF to produce the same key based hierarchy used. The key generated is the same each time; even after reboot. The generation of a new RSA 2048 bit key takes about 15 seconds. Typically these are created and then stored in NV using TPM2_EvictControl. Each TPM generates their own keys uniquely based on the seed.

There is also an Ephemeral hierarchy (TPM_RH_NULL), which can be used to create ephemeral keys.

Platform Configuration Registers (PCRs)

Contains hash digests for SHA-1 and SHA-256 with an index 0-23. These hash digests can be extended to prove the integrity of a boot sequence (secure boot).

Terminology

This project uses the terms append vs. marshall and parse vs. unmarshall.

Acronyms:

HAL: Hardware Abstraction Layer.
NV: Non-Volatile memory.
TPM: Trusted Platform Module.

Platform

The examples in this library are written for use on a Raspberry Pi and use the spi_dev interface.

IO Callback (HAL)

See the HAL manual in hal/README.md.

For interfacing to your hardware interface (SPI/I2C) a single HAL callback is used and configuration on initialization when calling TPM2_Init or wolfTPM2_Init.

There are HAL examples in hal directory for:

Atmel ASF
BareBox
Espressif ESP-IDF
Infineon TriCore
Linux
STM32 CubeMX
Xilinx

We also support an advanced IO option (--enable-advio/WOLFTPM_ADV_IO), which adds the register and read/write flag as parameter to the IO callback. This is required for I2C support.

Hardware

Tested with:

Infineon OPTIGA (TM) Trusted Platform Module 2.0 SLB9670, SLB9672 and SLB9673 (I2C).
- LetsTrust: Vendor for TPM development boards http://letstrust.de.
STMicro STSAFE-TPM, ST33TPHF2XSPI/2XI2C and ST33KTPM2X (SPI and I2C)
Microchip ATTPM20 module
Nuvoton NPCT65X or NPCT75x TPM2.0 modules
Nations Technologies Z32H330 or NS350 TPM 2.0 modules

Device Identification

Infineon SLB9670: TPM2: Caps 0x30000697, Did 0x001b, Vid 0x15d1, Rid 0x10 Mfg IFX (1), Vendor SLB9670, Fw 7.85 (4555), FIPS 140-2 1, CC-EAL4 1

Infineon SLB9672: TPM2: Caps 0x30000697, Did 0x001d, Vid 0x15d1, Rid 0x36 Mfg IFX (1), Vendor SLB9672, Fw 16.10 (0x4068), FIPS 140-2 1, CC-EAL4 1

Infineon SLB9673: TPM2: Caps 0x1ae00082, Did 0x001c, Vid 0x15d1, Rid 0x16 Mfg IFX (1), Vendor SLB9673, Fw 26.13 (0x456a), FIPS 140-2 1, CC-EAL4 1

STMicro ST33KTPM2XSPI TPM2: Caps 0x30000415, Did 0x0003, Vid 0x104a, Rid 0x 0 Mfg STM (2), Vendor ST33KTPM2XSPI, Fw 9.256 (0x0), FIPS 140-2 1, CC-EAL4 0

STMicro ST33TPHF2XSPI TPM2: Caps 0x1a7e2882, Did 0x0000, Vid 0x104a, Rid 0x4e Mfg STM (2), Vendor , Fw 74.8 (1151341959), FIPS 140-2 1, CC-EAL4 0

STMicro ST33TPHF2XI2C TPM2: Caps 0x1a7e2882, Did 0x0000, Vid 0x104a, Rid 0x4e Mfg STM (2), Vendor , Fw 74.9 (1151341959), FIPS 140-2 1, CC-EAL4 0

Microchip ATTPM20 TPM2: Caps 0x30000695, Did 0x3205, Vid 0x1114, Rid 0x 1 Mfg MCHP (3), Vendor , Fw 512.20481 (0), FIPS 140-2 0, CC-EAL4 0

Nations Technologies Inc. Z32H330 TPM 2.0 module Mfg NTZ (0), Vendor Z32H330, Fw 7.51 (419631892), FIPS 140-2 0, CC-EAL4 0

Nations Technologies Inc. NS350 TPM 2.0 module TPM2: Caps 0x30000615, Did 0x0701, Vid 0x9999, Rid 0x 1 Mfg NSG (0), Vendor NS350, Fw 30.30 (0x24042510), FIPS 140-2 1, CC-EAL4 0

Nuvoton NPCT650 TPM2.0 Mfg NTC (0), Vendor rlsNPCT , Fw 1.3 (65536), FIPS 140-2 0, CC-EAL4 0

Nuvoton NPCT750 TPM2.0 TPM2: Caps 0x30000697, Did 0x00fc, Vid 0x1050, Rid 0x 1 Mfg NTC (0), Vendor NPCT75x"!!4rls, Fw 7.2 (131072), FIPS 140-2 1, CC-EAL4 0

Building

Building wolfSSL

git clone https://github.com/wolfSSL/wolfssl.git
cd wolfssl
./autogen.sh
./configure --enable-wolftpm
make
sudo make install
sudo ldconfig

autogen.sh requires: automake and libtool: sudo apt-get install automake libtool

Building wolfSSL with an alternate directory

# cd /your-wolfssl-repo
./autogen.h # as necessary
./configure --prefix=~/workspace/my_wolfssl_bin --enable-all
make install

# then for some other library such as wolfTPM:

# cd /your-wolftpm-repo
./configure --enable-swtpm --with-wolfcrypt=~/workspace/my_wolfssl_bin

Build options and defines

--enable-debug          Add debug code/turns off optimizations (yes|no|verbose|io) - DEBUG_WOLFTPM, WOLFTPM_DEBUG_VERBOSE, WOLFTPM_DEBUG_IO
--enable-examples       Enable Examples (default: enabled)
--enable-wrapper        Enable wrapper code (default: enabled) - WOLFTPM2_NO_WRAPPER
--enable-wolfcrypt      Enable wolfCrypt hooks for RNG, Auth Sessions and Parameter encryption (default: enabled) - WOLFTPM2_NO_WOLFCRYPT
--enable-advio          Enable Advanced IO (default: disabled) - WOLFTPM_ADV_IO
--enable-i2c            Enable I2C TPM Support (default: disabled, requires advio) - WOLFTPM_I2C
--enable-checkwaitstate Enable TIS / SPI Check Wait State support (default: depends on chip) - WOLFTPM_CHECK_WAIT_STATE
--enable-smallstack     Enable options to reduce stack usage
--enable-tislock        Enable Linux Named Semaphore for locking access to SPI device for concurrent access between processes - WOLFTPM_TIS_LOCK
--enable-firmware       Enable firmware upgrade support for Infineon SLB9672/SLB9673 and ST ST33 (default: disabled) - WOLFTPM_FIRMWARE_UPGRADE

--enable-autodetect     Enable Runtime Module Detection (default: enable - when no module specified) - WOLFTPM_AUTODETECT
                        On Linux this also auto-detects /dev/tpmrm0 or /dev/tpm0 at runtime,
                        falling back to SPI if the kernel driver is not available.
--enable-infineon       Enable Infineon SLB9670/SLB9672/SLB9673 TPM Support (default: disabled) - WOLFTPM_SLB9670 / WOLFTPM_SLB9672
--enable-st             Enable ST ST33 Support (default: disabled) - WOLFTPM_ST33
--enable-microchip      Enable Microchip ATTPM20 Support (default: disabled) - WOLFTPM_MICROCHIP
--enable-nuvoton        Enable Nuvoton NPCT65x/NPCT75x Support (default: disabled) - WOLFTPM_NUVOTON

--enable-devtpm         Enable using Linux kernel driver for /dev/tpmX (default: disabled) - WOLFTPM_LINUX_DEV
                        Note: With autodetect (default) this is no longer required on Linux;
                        the kernel driver is tried automatically before SPI.
--enable-swtpm          Enable using SWTPM TCP protocol. For use with simulator. (default: disabled) - WOLFTPM_SWTPM
--enable-winapi         Use Windows TBS API. (default: disabled) - WOLFTPM_WINAPI

WOLFTPM_USE_SYMMETRIC   Enables symmetric AES/Hashing/HMAC support for TLS examples.
WOLFTPM2_USE_SW_ECDHE   Disables use of TPM for ECC ephemeral key generation and shared secret for TLS examples.
TLS_BENCH_MODE          Enables TLS benchmarking mode.
NO_TPM_BENCH            Disables the TPM benchmarking example.

Note: For the I2C support on Raspberry Pi you may need to enable I2C. Here are the steps:

Edit sudo vim /boot/config.txt
Uncomment dtparam=i2c_arm=on
Reboot sudo reboot

Building Infineon

Support for SLB9670 or SLB9672 (SPI) / SLB9673 (I2C)

Build wolfTPM:

git clone https://github.com/wolfSSL/wolfTPM.git
cd wolfTPM
./autogen.sh
./configure --enable-infineon [--enable-i2c]
make

The default is SLB9672/SLB9673 (if I2C). To specify SLB9670 use --enable-infineon=slb9670.

Building ST ST33