swtpm_setup - Man Page

Swtpm utility to simulate the manufacturing of a TPM 1.2 or 2.0

Synopsis

swtpm_setup [OPTIONS]

Description

swtpm_setup is a tool that prepares the intial state for a libtpms-based TPM.

For creating the initial state of a TPM 1.2, swtpm_setup must be run either as root or as the user the that tcsd requires, which is typically tss.

The following options are supported:

--runas <userid>

Use this userid to run swtpm_setup.sh; by default 'tss' is used.

--config <file>

Path to configuration file containing the tool to use for creating certificates; see also swtpm_setup.conf

If this parameter is not provided, the default configuration file /etc/swtpm_setup.conf will be used. If the environment variable XDG_CONFIG_HOME is set, the configuration file is assumed to be $XDG_CONFIG_HOME/swtpm_setup.conf.

--tpm-state <dir> or --tpmstate <dir>

Path to a directory where the TPM's state will be written into; this is a mandatory argument

--tpm <path to executable>

Path to the TPM executable; this is an optional argument and by default the swtpm executable found in the PATH will be used.

--tpm2

Do setup on a TPM 2; by default a TPM 1.2 is setup.

--createek

Create the EK

--allow-signing

Create an EK that can sign. This option requires --tpm2.

Note that the TCG specification “EK Credential Profile For TPM Family 2.0; Level 0” suggests in its section on “EK Usage” that “the Endorsement Key can be a created as a decryption or signing key.” However, some platforms will not accept an EK as a signing key, or as a signing and encryption key, and therefore this option should be used very carfully.

--decryption

Create an EK that can be used for key encipherment. This is the default unless --allow-signing is passed. This option requires --tpm2.

--ecc

Create elliptic curve crypto (ECC) keys; by default RSA keys are generated.

--take-ownership

Take ownership; this option implies --createek

--ownerpass  <password>

Provide custom owner password; default is ooo

--owner-well-known

Use a password of all zeros (20 bytes of zeros) as the owner password

--srkpass <password>

Provide custom SRK password; default is sss

--srk-well-known

Use a password of all zeros (20 bytes of zeros) as the SRK password

--create-ek-cert

Create an EK certificate; this implies --createek (NOT SUPPORTED YET)

--create-platform-cert

Create a platform certificate; this implies --create-ek-cert

--lock-nvram

Lock NVRAM access

--display

At the end display as much info as possible about the configuration of the TPM

--logfile <logfile>

The logfile to log to. By default logging goes to stdout and stderr.

--keyfile <keyfile>

The key file contains an ASCII hex key consisting of 32 hex digits with an optional leading '0x'. This is the key to be used by the TPM emulator for encrypting the state of the TPM.

--keyfile-fd <file descriptor>

Like --keyfile but the key will be read from the file descriptor.

--pwdfile <passphrase file>

The passphrase file contains a passphrase from which the TPM emulator will derive the encyrption key from and use the key for encrypting the TPM state.

--pwdfile-fd <file descriptor>

Like --pwdfile but the passphrase will be read from the file descriptor.

--ciper <cipher>

The cipher may be either aes-cbc or aes-128-cbc for 128 bit AES encryption, or aes-256-cbc for 256 bit AES encryption. The same cipher must be used on the swtpm command line later on.

--overwrite

Overwrite existing TPM state. All previous state will be erased. If this option is not given and an existing state file is found, an error code is returned.

--not-overwrite

Do not overwrite existing TPM state. If exising TPM state is found, the program ends without an error.

--vmid <VM ID>

Optional VM ID that can be used to keep track of certificates issued for VMs (or containers). This parameter will be passed through to the tool used for creating the certificates and may be required by that tool.

--pcr-banks <PCR banks>

Optional comma-separated list of PCR banks to activate. Providing '-' allows to skip the selection and activates all PCR banks. By default the sha1 and sha256 banks are activated.

--swtpm_ioctl <executable>

Pass the path to the swtpm_ioctl executable. By default the swtpm_ioctl in the PATH is used.

--tcsd-system-ps-file <file>

A file to copy TCSD's system_ps_file to. The system_ps_file contains the TPM 1.2 SRK public key after taking ownership of the TPM. The file is needed by TCSD for key related functions.

This option is only useful with TPM 1.2 and in if ownership is taken.

--print-capabilities (since v0.2)

Print capabilities that were added to swtpm_setup after version 0.1. The output contains the following:

    {
      "type": "swtpm_setup",
      "features": [
        "cmdarg-keyfile-fd",
        "cmdarg-pwdfile-fd"
      ]
    }

The meaning of the feature verbs is as follows:

cmdarg-key-fd

The --keyfile-fd option is supported.

cmdarg-pwd-fd

The --pwdfile-fd option is supported.

--help, -h

Display the help screen

Example Usage

To simulate manufacturing of a TPM, one would typically run the following command:

  #> sudo swtpm_setup --tpmstate /tmp/mytpm1/ \
      --create-ek-cert --create-platform-cert --lock-nvram

Note: since setting up a TPM 1.2 relies on the tcsd for some of its operations, swtpm_setup has to be run as root so that it can invoke the tcsd either as root or tss user.

A normal user can also simulate the manufacturing of a TPM 2 using the swtpm-localca plugin. The following example assumes that the user has set the environment variable XDG_CONFIG_HOME as follows (using bash for example):

    export XDG_CONFIG_HOME=~/.config

Note: The XDG_CONFIG_HOME variable is part of the XDG Base Directory Specification.

The following configuration files need to be created:

~/.config/swtpm_setup.conf:

    # Program invoked for creating certificates
    create_certs_tool= /usr/share/swtpm/swtpm-localca
    create_certs_tool_config = ${XDG_CONFIG_HOME}/swtpm-localca.conf
    create_certs_tool_options = ${XDG_CONFIG_HOME}/swtpm-localca.options

~/.config/swtpm-localca.conf:

    statedir = ${XDG_CONFIG_HOME}/var/lib/swtpm-localca
    signingkey = ${XDG_CONFIG_HOME}/var/lib/swtpm-localca/signkey.pem
    issuercert = ${XDG_CONFIG_HOME}/var/lib/swtpm-localca/issuercert.pem
    certserial = ${XDG_CONFIG_HOME}/var/lib/swtpm-localca/certserial

~/.config/swtpm-localca.options:

    --platform-manufacturer Fedora
    --platform-version 2.12
    --platform-model QEMU

The following commands now create a TPM 2 with an EK and platform certificate. The state of the TPM 2 will be stored in the directory ${XDG_CONFIG_HOME}/mytpm1.

  #> mkdir -p ${XDG_CONFIG_HOME}/mytpm1
  #> swtpm_setup --tpm2 --tpmstate ${XDG_CONFIG_HOME}/mytpm1 \
      --create-ek-cert --create-platform-cert --lock-nvram

See Also

swtpm_setup.conf

Reporting Bugs

Report bugs to Stefan Berger <stefanb@linux.vnet.ibm.com>

Referenced By

The man page swtpm_setup.sh(8) is an alias of swtpm_setup(8).

2019-07-09 swtpm